U.S. patent application number 15/193605 was filed with the patent office on 2018-05-03 for amidated dopamine neuron stimulating peptide restoration of mitochondrial activity.
The applicant listed for this patent is University of Kentucky Research Foundation. Invention is credited to Luke H. BRADLEY, Don Marshall GASH, Greg A. GERHARDT.
Application Number | 20180117113 15/193605 |
Document ID | / |
Family ID | 47830382 |
Filed Date | 2018-05-03 |
United States Patent
Application |
20180117113 |
Kind Code |
A1 |
BRADLEY; Luke H. ; et
al. |
May 3, 2018 |
Amidated Dopamine Neuron Stimulating Peptide Restoration of
Mitochondrial Activity
Abstract
The present invention relates to the use of novel proteins,
referred to herein as amidated glial cell line-derived neurotrophic
factor (GDNF) peptides (or "Amidated Dopamine Neuron Stimulating
peptides (ADNS peptides)"), for treating brain diseases and
injuries that result in dopaminergic deficiencies and mitochodrial
dysfunction, e.g., reduced complex I enzyme activity.
Inventors: |
BRADLEY; Luke H.;
(Lexington, KY) ; GASH; Don Marshall; (Lexington,
KY) ; GERHARDT; Greg A.; (Nicholasville, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
University of Kentucky Research Foundation |
Lexington |
KY |
US |
|
|
Family ID: |
47830382 |
Appl. No.: |
15/193605 |
Filed: |
June 27, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13586617 |
Aug 15, 2012 |
9402875 |
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15193605 |
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12646511 |
Dec 23, 2009 |
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13586617 |
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12508916 |
Jul 24, 2009 |
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12646511 |
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12447213 |
Mar 25, 2010 |
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PCT/US2007/022696 |
Oct 26, 2007 |
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12508916 |
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60854693 |
Oct 27, 2006 |
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61140365 |
Dec 23, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 38/08 20130101;
A61K 38/185 20130101; A61P 25/16 20180101; A61K 38/10 20130101;
A61P 25/28 20180101; A61P 25/00 20180101 |
International
Class: |
A61K 38/08 20060101
A61K038/08; A61K 38/18 20060101 A61K038/18; A61K 38/10 20060101
A61K038/10 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with U.S. government support under
grant numbers PO1 AG13494, P50 NS39787-01, R03 NS075694 and T32
AG000242 awarded by the National Institutes of Health. The U.S.
government has certain rights in the invention.
Claims
1-4. (canceled)
5. A method for treating a condition associated with a deficiency
in mitochondrial complex I enzyme activity in a subject comprising
administering to a subject in need thereof a pharmaceutically
effective amount of a composition comprising (a) a purified
Amidated Dopamine Neuron Stimulating peptide (ADNS peptide)
comprising the amino acid sequence ERNRQAAAANPENSRGK-amide (SEQ ID
NO: 2); (b) a purified ADNS peptide comprising the amino acid
sequence FPLPA-amide (SEQ ID NO: 3); or (c) a purified ADNS peptide
comprising the amino acid sequence PPEAPAEDRSL-amide (SEQ ID NO:
4), or mixtures thereof, and at least one of a pharmaceutically
acceptable vehicle, excipient, and diluent, wherein the composition
is administered nasally, wherein the subject in need thereof has
early onset Parkinson's Disease, ALS, or a spinal cord injury,
wherein the composition is administered in an amount that restores
mitochondrial activity as evidenced by an increase in levels of at
least one of dopamine and a dopamine metabolite in the subject.
6. The method of claim 5, wherein the ADNS peptide is a purified
ADNS peptide comprising the amino acid sequence
ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2).
7. The method of claim 5, wherein the ADNS peptide is a purified
ADNS peptide comprising the amino acid sequence FPLPA-amide (SEQ ID
NO: 3).
8. The method of claim 5, wherein the ADNS peptide is a purified
ADNS peptide comprising the amino acid sequence PPEAPAEDRSL-amide
(SEQ ID NO: 4).
9-16. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of Ser. No. 13/586,617,
filed Aug. 15, 2012, which is a continuation in part of U.S.
application Ser. No. 12/646,511, filed Dec. 23, 2009, which is a
continuation-in-part of U.S. application Ser. No. 12/508,916, filed
Jul. 24, 2009, which is a continuation-in-part of U.S. application
Ser. No. 12/447,213 filed Apr. 24, 2009, which is a 371 application
of PCT/US2007/022696 filed Oct. 26, 2007, which claims priority of
U.S. Application Ser. No. 60/854,693 filed Oct. 27, 2006, the
disclosures of which are incorporated herein in their entireties.
This application claims priority under 35 U.S.C. .sctn. 119(e) to
U.S. Provisional Application Ser. No. 61/140,365 filed Dec. 23,
2008, incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0003] The present invention relates to novel proteins, referred to
herein as amidated glial cell line-derived neurotrophic factor
(GDNF) peptides (or "Dopamine Neuron Stimulating peptides" ("DNSP")
or "Amidated Dopamine Neuron Stimulating peptides" ("ADNS
peptides")), that are useful for treating brain diseases, injuries
that result in dopaminergic deficiencies, and diseases or
conditions associated with inhibition of mitochondrial
activity.
BACKGROUND OF THE INVENTION
[0004] Neurotrophic factors are endogenous proteins that modulate
cell signaling pathways regulating stem cell proliferation,
neuronal differentiation, differentiation, growth and regeneration
(Barde Y., Neuron 2:1525-1534 (1989); Gotz, R., et al., Comp
Biochem Physiol Pharmacol Toxicol Endocrinol 108: 1-10 (1994); and
Goldman, S. A., J. Neurobiol 36: 267-86 (1998)). They are generally
small, soluble proteins with molecular weights between 13 and 24
KDa and often function as homodimers. Because of this physiological
role, neurotrophic factors are useful in treating the degeneration
of nerve cells and the loss of differentiated function that occurs
in a variety of neurodegenerative diseases.
[0005] Many neurotrophic factors are both neuroprotective
(protecting neurons from injury) and neurorestorative (promoting
structural and functional regeneration). The best defined
protective functions are seen during neural development. During
development, excessive numbers of neurons are generated in many
brain regions. Developing neurons that fail to make connections
with appropriate trophic factor producing target cells are deprived
of necessary neurotrophic factors and die. Those neurons that
establish connections survive and function properly (e.g. NGF; see
Campenot, R. B. and MacInnis, B. L, J Neurobiol 58: 217-229
(2004)). Neurotrophic factors are also capable of promoting the
re-growth of damaged neurons and their processes both in vitro and
in animal models (see Lad, S. P. et al., J Blol Chem 278:
24808-24817 (2003a) and Lad, S. P. et al., Curr Drug Targets CNS
Neurol Disord 2: 315-334 (2003b)). Identifying neurotrophic factors
with the right combination of protective and restorative actions
and developing effective strategies for drug delivery have profound
therapeutic implications for Parkinson's disease, Alzheimer's
disease, Huntington's disease and other degenerative processes in
the brain (including those induced by brain injury).
[0006] Glial cell line-derived neurotrophic factor (GDNF) is a
trophic factor shown to dramatically protect and enhance the
function of dopamine neurons in vitro and in vivo in rodents and
monkeys (Beck, K. D., et al, Nature, 373:339-41 (1995); and
Bjorklund, A., et al., "Brain Res., 886:82-98 (2000), Gash, D. M.,
et al., Nature, 380:252-255 (1996); Grondin, R., et al., Brain,
125:2191-2201 (2002); Grondin, R., et al., J Neurosci.,
23:1974-1980 (2003); Hebert M. A., et al., J. Pharm. Exp. Ther.,
279:1181-1190 (1996); Hebert M. A. and Gerhardt, G. A.," J. Pharm.
Exp. Ther., 282:760-768 (1997); Hou, J. G. G., et al., J.
Neurochem., 66:74-82 (1996); Kordower, J. H., et al., Ann Neurol.,
46(3):419-424 (1999); Kordower, J. H., et al., Science, 290:767-773
(2000); Palfi, S., et al., J Neurosci., 22:4942-4954 (2002); Tomac,
A., et al., Nature, 373:335-339 (1995)).
[0007] The current standard treatment, levodopa, is palliative and
does not prevent the relentless progression of Parkinson's
degeneration. GDNF exerts effects on dopamine neurons that slow the
process of Parkinson's disease and even reverses some of the
degenerative changes. Preclinical studies conducted to date suggest
that GDNF exerts at least three general trophic actions on dopamine
neurons in the substantia nigra: pharmacological upregulation,
restoration and neuroprotection. With regard to pharmacological
upregulation, GDNF upregulates dopaminergic functions, such as
increasing the evoked release of dopamine (Gerhardt, G. A. et al.,
Brain Res 817: 163-171 (1999) and Grondin et al., 2003). It also
appears to modulate the phosphorylation of TH (Salvatore, M. et al.
J Neurochem. 90:245-54., (2004)). With regard to restoration, GDNF
increases the number of neurons expressing the dopamine markers TH
and DAT in the substantia nigra (Gash et al., 1996; Kordower et
al., 2000; and Grondin et al., 2002). This suggests that one
trophic action is to stimulate recovery of injured/quiescent nigral
neurons. Supporting this interpretation is the consistent
observation that GDNF promotes increases in dopamine neuron
perikaryal size and the number of neurites. With regard to
neuroprotection, nigrostriatal administration of GDNF either
shortly before or following a neurotoxic challenge (e.g. 6-OHDA,
methyl-amphetamine or MPTP) protects dopamine neurons from injury
in rodents and nonhuman primates (Kordower et al., 2000 and Fox, C.
M., Brain Res 896:56-63 (2001)).
[0008] Accordingly, GDNF therapy is expected to be helpful in the
treatment of nerve damage caused by conditions that compromise the
survival and/or proper function of one or more types of nerve
cells. Such nerve damage may occur from a wide variety of different
causes. Nerve damage may occur to one or more types of nerve cells
by, for example: (1) physical injury, which causes the degeneration
of the axonal processes and/or nerve cell bodies near the site of
injury; (2) temporary or permanent cessation of blood flow to parts
of the nervous system, as in stroke; (3) intentional or accidental
exposure to neurotoxins, such as chemotherapeutic agents (e.g.,
cisplatinum) for the treatment of cancer, dideoxycytidine (ddC) for
the treatment of AIDS; (4) chronic metabolic diseases, such as
diabetes or renal dysfunction; or (5) neurodegenerative diseases
such as Parkinson's disease, Alzheimer's disease, and Amyotrophic
Lateral Sclerosis (ALS), which result from the degeneration of
specific neuronal populations.
[0009] GDNF therapy may be particularly helpful in the treatment of
neurodegenerative conditions involving the degeneration of the
dopaminergic neurons of the substantia nigra, such as Parkinson's
disease. The expected impact of GDNF therapy is not just to produce
an increase in the dopaminergic neurotransmission at the
dopaminergic nerve terminals in the striatum (which will result in
a relief of the symptoms), but also to slow down, or even stop, the
progression of the degenerative processes and to repair the damaged
nigrostriatal pathway and restore its function. GDNF may also be
used in treating other forms of damage to or improper function of
dopaminergic nerve cells in human subjects. Such damage or
malfunction may occur in schizophrenia and other forms of
psychosis. The only current treatments for such conditions are
symptomatic and require drugs which act upon dopamine receptors or
dopamine uptake sites, consistent with the view that the improper
functioning of the dopaminergic neurons which innervate these
receptor-bearing neuronal populations may be involved in the
disease process.
[0010] However, initial clinical trials involving ventricular
delivery of GDNF showed no statistically significant
differentiation of the placebo and active treatment groups (Nutt,
J. G. et al., Neurology 60: 69-73 (2003)), perhaps because
insufficient amounts of GDNF reached critical target sites from the
CSF (Ai, Y. et al., J Comp Neurol 461: 250-26125 (2003); and
Kordower, J. H., et al. (2000)). In addition, a phase 2 trial
evaluating intraputamenal delivery of glial cell line-derived
neurotrophic factor (GDNF) for the treatment of Parkinson's disease
failed to achieve its primary end point, a 25% improvement on the
Unified Parkinson Disease Rating Scale (UPDRS) motor score "off"
medication after six months of treatment (Lang, A. E. et al., Ann
Neurol 59:459-466 (2006)). There are strong indications from
studies in rhesus monkeys using the same delivery system and
protocol followed in the phase 2 study that drug bioavailability
significantly contributed to the failure of the trial (Salvatore et
al., Exp Neurol 202(2):497-505 (2006)). The concentration of GDNF
around the catheter tip and limited diffusion into surrounding
brain parenchyma was limited to a brain volume representing 2-9% of
the human putamen. Thus GDNF distribution in the phase 2 trial was
likely limited to a small brain region, and could affect only a
limited segment of the brain undergoing parkinsonian
degeneration.
[0011] Successful trophic factor therapy requires site-specific
delivery and distribution of the trophic factor throughout the
target tissue (the putamen for Parkinson's disease). The blood
brain barrier effectively blocks entry from blood borne proteins,
including trophic factors. Infusions into the cerebrospinal fluid
are not effective in humans because of brain size and may produce
unwanted side effects by stimulating other trophic factor
responsive populations such as sensory neurons.
[0012] In addition to focal delivery into the appropriate site, the
delivery must be tightly regulated. Regardless of the method used
to deliver GDNF (i.e., direct infusion, stem cells, encapsulated
cells, gene therapy) prolonged elevated levels of GDNF in the brain
outside of the target area may produce adverse side-effects.
Circulating antibodies to GDNF are one possible outcome and it is
quite typical to find antibodies to endogenous proteins used
therapeutically (e.g. beta interferon and insulin, see Durelli, L.,
et al., Front Biosci 9: 2192-2204 (2004) and Stoever, J. A. et al.,
Diabetes Technol Ther 4: 157-161 (2002)). The effects of
circulating GDNF antibodies are not known. Focal Purkinje cell
lesions have been reported in some monkeys receiving high levels of
GDNF in a toxicology study (see Sherer, T. B., et al., Movement Dis
21:136-141 (2006)). Another possible side-effect is aberrant
sprouting and tyrosine hydroxylase downregulation of the
nigrostriatal dopaminergic pathway in rats exposed to high GDNF
levels from viral vector gene transfer (Georgievska, B., et al,
Neuroreport 13: 75-82 (2002)). Also, increased neuronal death has
been reported in rats with elevated GDNF from viral vector gene
transfer in a stroke model (Arvidsson, A. et al., Neurobiol Dis 14:
542-556, (2003)).
[0013] While GDNF has not met the criteria for clinical efficacy in
the two phase 2 trials conducted to date (Nutt et al., 2003; Lang
et al., 2006), it appears to be the most potent dopaminergic
trophic factor found to date. Thus, the ideal drug for treating
Parkinson's disease and other neurodegenerative processes in the
brain would possess the positive trophic actions of GDNF. Delivery
could be targeted to the appropriate brain area by any of a number
of methods including direct infusion, viral vectors or even nasal
sprays. In particular, biologically active peptides with trophic
actions may offer many of the desired properties. To date, such
biologically active peptides have not been identified.
[0014] A crude peptide extract from the brain cerebrolysin has been
tested in human studies, with modest effects reported (Lukhanina,
E. P. et al., Zh Nevrol Psikhiatr Im S S Korsakova 104: 54-60
(2004)). Three small molecule compounds have also been tested in
Parkinson's disease patients: the tripeptide glutathione,
tocopherol, and Coenzyme Q10 (Weber, C. A., et al., Ann
Pharmacother 40: 935-938 (2006)). The three small molecule
compounds also appear to have only minor benefits for patients.
[0015] Consequently, there continues to exist a long-felt need for
effective agents and methods for the treatment and prevention of
brain diseases and injuries that result in dopaminergic
deficiencies. Accordingly, it is an object of the present invention
to provide agents for treating and preventing such diseases and
injuries in a subject, comprising novel amidated GDNF-derived
peptides that have dopaminergic trophic factor activity. This and
other such objectives will be readily apparent to the skilled
artisan from this disclosure.
SUMMARY OF THE INVENTION
[0016] The present invention provides a method for treating a brain
disease or injury resulting in dopaminergic deficiencies, or
diseases and conditions associated with mitochondrial dysfunction,
e.g., diseases and conditions associated with inhibited or reduced
levels of complex I enzyme (NADH:ubiquinone oxidoreductase)
activity. Treating a brain disease includes, e.g., relieving the
symptoms of the disease or condition, as well as slowing down, or
even stopping, the progression of the disease, including the repair
or the damaged nigrostriatal pathway and restoring its function.
The methods comprise administering a pharmaceutically effective
amount of a composition comprising at least one of the following
peptides: (a) a purified ADNS peptide comprising the amino acid
sequence ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2); (b) a purified
ADNS peptide comprising the amino acid sequence FPLPA-amide (SEQ ID
NO: 3); and (c) a purified ADNS peptide comprising the amino acid
sequence PPEAPAEDRSL-amide (SEQ ID NO: 4), to a subject in need
thereof wherein the composition also comprises at least one of a
pharmaceutically acceptable vehicle, excipient, and diluent.
Preferably, the subject is a mammal, and most preferably, the
subject is human. The methods also encompass ameliorating or
inhibiting the effects of a mitochodrial toxin, e.g., a
mitochodrial complex I toxin, by contacting mitochodria or cells
comprising mitochondria with at least one of (a) a purified ADNS
peptide comprising the amino acid sequence ERNRQAAAANPEN-SRGK-amide
(SEQ ID NO: 2); (b) a purified ADNS peptide comprising the amino
acid sequence FPLPA-amide (SEQ ID NO: 3); and (c) a purified ADNS
peptide comprising the amino acid sequence PPEAPAEDRSL-amide (SEQ
ID NO: 4) or truncated fragments thereof in an amount and for a
time sufficient to ameliorate or inhibit the effects of the
mitochondrial toxin.
BRIEF DESCRIPTION OF THE FIGURES
[0017] FIG. 1 depicts the nucleotide sequence (top strand) and
amino acid sequence (bottom strand) of mature human GDNF (SEQ ID
NO: 5 and SEQ ID NO: 1).
[0018] FIG. 2 depicts the post-translational processing of splice
form 1 of human GDNF. Sequences from top to bottom are: SEQ ID NO:
6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID
NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 3, SEQ ID NO:4,
and SEQ ID NO: 2.
[0019] FIG. 3 depicts the precursor segments of the ADNS peptides
ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2), FPLPA-amide (SEQ ID NO:3),
and PPEAPAEDRSL-amide (SEQ ID NO:4). From top to bottom SEQ ID NO:
8, SEQ ID NO: 14, and SEQ ID NO:15.
[0020] FIG. 4 depicts the average K.sup.+-evoked release of
dopamine in Fischer 344 rats treated with ADNS peptides.
[0021] FIG. 5 depicts the increase in major metabolites of dopamine
in Fischer 344 rats treated with ADNS peptides.
[0022] FIG. 6 depicts the increased survival of dopamine neurons in
cell cultures treated with ADNS peptides.
[0023] FIGS. 7A and 7B depict the results of in vivo microdialysis
used to investigate the dynamics of dopamine release in the basal
ganglia of the right putamen following treatment with ADNS
peptides.
[0024] FIGS. 8A-8F depict the histopathological response to the
injection of ADNS peptides in the nigral region using standard
histochemical techniques.
[0025] FIGS. 9A-9D depict a series of photomicrographs evaluating
the substantia nigra compacta (SNc) containing the population of
dopamine neurons that degenerates in Parkinson's disease after
treatment with ADNS peptides.
[0026] FIGS. 10A and 10B depict the sequence origin and homology of
dopamine neuron stimulating peptide-11 (DNSP-11).
[0027] FIGS. 11A-11D depict the neurotropic effects of DNSP-11 and
GDNF on mesencephalic (FIG. 11A and FIG. 11B) and MN9D (FIG. 11C
and FIG. 11D) dopaminergic cells.
[0028] FIGS. 12A-12C depict the effects of DNSP-11 in normal (FIG.
12A) and unilateral 6-OHDA-lesioned (FIG. 12B and FIG. 12C)
rats.
[0029] FIG. 13 depicts the interactions of DNSP-11 with protein
partners.
[0030] FIG. 14 depicts the gel filtration analysis of the
interaction between GAPDH and GDNF.
[0031] FIGS. 15A-15C depict the solubility and stability of DNSP-11
at various storage and experimental conditions: mean residue
ellipticity (MRE) at 200 nm (FIG. 15A); Reverse Phase HPLC
(RP-HPLC) results (FIG. 15B); peptide stability at 37.degree. C.
for one month (FIG. 15C).
[0032] FIG. 16 shows the effects of citrate vehicle or DNSP-11 on
resting levels of DOPAC one month after a single infusion.
[0033] FIG. 17 shows the broad distribution of DNSP-11 in the rat
substantia nigra region of the midbrain within 30 minutes of
DNSP-11 injection (panels A-F).
[0034] FIGS. 18A and 18B show the DNSP-11 increased State III
oxygen consumption vs. vehicle in both the SN and striatum, 28 days
post bilateral intranigral injections (*p<0.05 vs control,
two-tailed, unpaired tests). The results in the Substantia nigra at
28 days (FIG. 18A); the results in the Striatum at 28 days (FIG.
18B).
[0035] FIG. 19A demonstrates that DNSP-11 produced a significant,
about 50%, decrease in apomorphine-induced rotational behavior and
FIG. 19B demonstrates that DNSP-11 produced significantly increased
levels of dopamine and the dopamine metabolite, DOPAC, by about
100% in the substantia nigra.
[0036] FIG. 20A-20I demonstrate the protective effect of DNSP-11 on
MN9D and B65 cells incubated with rotenone, NIPP+ or TaClo as
determined in JC-1 mitochodrial membrane potential assay (FIG.
20A-20D), a TUNEL assay (FIG. 20E-20G) and Capase 3 assay (FIG.
20H-20I).
[0037] FIG. 21A depicts the effect of GDNF and DNSP-11 on Erk1/2
activation in MN9D, and FIG. 21B depicts the effect of GDNF and
DNSP-11 on Erk1/2 activation in B65 cells.
[0038] FIG. 22 depicts the evaluation of DNSP-11's effect on oxygen
consumption rates in MN9D cells.
[0039] FIG. 23A depicts the oxygen consumption rate of MN9D cells
exposed to TaClo with or without DNSP-11 and FIG. 23B depicts the
oxygen consumption rate of MN9D cells exposed to rotenone with or
without DNSP-11.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Human glial cell line-derived neurotrophic factor (hGDNF) is
synthesized as a precursor that is processed and secreted as a
mature protein of 134 amino acids. Mature human GDNF has the amino
acid sequence depicted in FIG. 1 (SEQ ID NO:1).
[0041] The present invention is related to the realization that
human GDNF (splice form 1) precursor protein conforms to a rather
exacting sequence profile characteristic of neuropeptide precursor
proteins. GDNF is expressed in at least three isoforms that result
from alternative splicing of mRNA. Proteins expressed from these
RNA splice variants differ in their N-terminal regions (see NCBI
entry NP 000505 for isoform 1; NCBI entry NP 964701 for isoform 2;
and NCBI entry NP 954704 for isoform 3). Isoforms 1 and 2 are
secretory protein precursors with N-terminal signal peptides.
Isoform 3 is likely a nuclear-targeted protein with a nuclear
localization signal (NLS), but no signal peptide. The three
isoforms are differentially expressed, apparently under regulatory
control.
[0042] All of the isoforms contain the sequence that is considered
mature GDNF with "full biological activity" (residues 78-211 in
isoform 1). In fact, recombinant proteins further truncated at the
N-terminus are purported to have the "full biological activity".
From the fact that three separate precursors of the same GDNF
molecule are expressed under separate regulation, two with signal
peptides and the third with a probable nuclear localization signal,
suggests that there are both nuclear and cell surface receptors for
GDNF.
[0043] The separately regulated expression of two different
secretory isoforms (isoforms 1 and 2) suggests a biologically
significant function for the different N-terminal sequences of the
isoforms. The conventional wisdom is that residues 20-77 of isoform
1 precursor constitute a "domain propeptide". The present invention
provides a new interpretation of the importance of the 20-77
"domain propeptide" region of isoform 1 precursor. The "domain
propeptide" segment of isoform 1 precursor is the metabolic
precursor of two small amidated peptides, according to well
established enzymatic pathways for release of peptide amide
hormones and neuropeptides from their precursor proteins. The two
small amidated peptides are FPLPA-amide (SEQ ID NO: 3) and
PPEAPAEDRSL-amide (SEQ ID NO: 4).
[0044] Furthermore, a third small amidated peptide,
ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2), may be released from
consensus enzymatic processing of residues 88-110 of the isoform 1
precursor. This consensus peptide amide precursor occupies the
N-terminal sequence of "mature GDNF", which is presumably not
critical or at least includes residues that are not critical for
biological activity, according to the patent literature. The
isoform 2 precursor contains the sequence FPLPA (SEQ ID NO: 6), but
does not contain the amidation signal (GKR, residues 25-27) in the
case of Isoform 1 precursor. Isoform 2 is not, in other words, a
potential precursor of FPLPA-amide (SEQ ID NO: 3) according to
known enzymatic pathways. Isoform 3 does not contain the sequence
FPLPA at all, so likewise can not be a metabolic precursor of
FPLPA-amide (SEQ ID NO: 3). Both isoforms 1 and 2 are consensus
precursors of ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2), but isoform 3
is not.
[0045] Thus, human GDNF isoform 1 is a secretory protein that can
potentially yield three small amidated peptides by consensus
enzymatic pathways known to release peptide amide hormones and
neuropeptides from their known precursor proteins. This is a rare
combination of enzymatic processing motifs and strongly suggests
that GDNF isoform 1 precursor is the metabolic precursor of up to
three small ADNS peptides, in addition to the larger C-terminal
domain that is widely supposed to posses the "full biological
activity" of GDNF. C-terminal amidation in natural peptides is
highly correlated with receptor mediated signal transduction: about
half of the known peptide hormones and neuropeptides and C-terminal
amidation is rare and almost unknown among other peptides of
biological origin.
[0046] Animal studies with synthetic peptides corresponding to the
consensus products of Isoform 1 precursor protein are consistent
with some or all of these peptides being biologically active and
involved in regulation of dopamine metabolism. This is to be
expected from a protein that yields multiple biologically active
regulatory peptides in a fixed molar ratio. The fact that the
different Isoforms of GDNF precursor protein are consensus
precursors of different combinations of amidated peptides in
addition to GDNF, suggests a reason for differential expression of
three separate isoforms (in addition to differential secretory and
nuclear routing).
[0047] According to this model, splice form 1 of human GDNF may be
post-translationally processed in vivo to yield three small
amidated peptides, as indicated in FIG. 2. These small amidated
peptides may mediate some or all of the biological effects of GDNF.
The present invention is based on the unexpected discovery that
these small amidated fragments of the mature GDNF protein retain
the biological activity of GDNF.
[0048] Thus, the ADNS peptides of the present invention include
these three small amidated peptides, which are represented by the
amino acid sequences ERNRQAAAANPENSRGK-amide; FPLPA-amide; and
PPEAPAEDRSL-amide (SEQ ID NOs:2, 3, and 4, respectively).
[0049] The ADNS peptides of the present invention are useful for
treatment and prevention of neurodegenerative conditions involving
dopaminergic deficiencies, such as Parkinson's disease,
age-associated motor and cognitive slowing, and other diseases and
injuries to the brain, e.g., Alzheimer's Disease. Also an
embodiment of this invention is a method for treating
neurodegenerative conditions associated with mitochondrial
dysfunction, particularly reduced mitochondrial Complex I enzyme
activity, by administering the peptides of this invention to a
subject in need thereof in an amount and for a time sufficient to
treat or prevent the condition. Such conditions include, e.g.,
early onset Parkinson's Disease, Bipolar disorder, Schizophrenia,
ALS, traumatic brain injury, spinal cord injury, stroke, congenital
diseases, Leber's hereditary optic neuropathy, Leigh Syndrome,
encephalomyopathy, mitochondrial myopathy, encephalopathy, lactic
acidosis, and stroke-like episodes (MELAS), myoclonic epilespy and
ragged-red fiber disease (MERFF), particularly early onset
Parkinson's Disease, traumatic brain injury, spinal cord injury, or
ALS.
[0050] Furthermore this invention relates to method for treating or
preventing the effects induced by toxins, e.g., pesticides and
solvents, particularly mitochondrial Complex I toxins, e.g.,
rotenone, MPP+, MPTP, and TaClo, by contacting mitochondria or
mitochondria-containing cells in need thereof with the ADNS
peptides of this invention in an amount and for sufficient duration
to treat or prevent the effects of the mitochondrial toxins. The
mitochondria and cells may be contacted with the ADNS peptides of
this invention prior to, during, and/or after exposure to the
toxin.
[0051] Thus an embodiment of this invention is a method for
protecting or restoring mitochondrial activity, by contacting
mitochodria, mitochondria-containing cells, or a subject, having
reduced mitochondrial activity with a purified ADNS peptide of this
invention, e.g., a purified comprising the amino acid sequence
ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2), FPLPA-amide (SEQ ID NO: 3);
or PPEAPAEDRSL-amide (SEQ ID NO: 4), or mixtures thereof, or
fragments thereof (for example nested fragments), in an amount and
for sufficient time to restore, at least partially, mitochondrial
activity, particularly complex I enzyme activity. The reduced
mitochondrial activity may be the result of the effects of the
toxin, e.g., a toxin that inhibits mitochondria complex I enzyme
(NADH:ubiquinone oxidoreductase) activity, a traumatic brain
injury, a spinal cord injury, or a genetic condition that results
in mitochodrial dysfunction, particularly a reduction in complex I
enzyme activity. In an embodiment of the invention the
mitochondria, mitochondria-containing cells or subject having
mitochondrial dysfunction, particularly reduced complex I enzyme
activity, may be treated by contacting the mitochondria, cells or
subject with the ADNS peptide of this invention, in an amount and
for a time sufficient to restore, at least partially, mitochondrial
activity, preferably complex I enzyme activity. For examples, where
mitochondrial activity has been reduced in response to a traumatic
brain injury or a spinal cord injury or a genetic condition, the
peptides may be administered to the subject within minutes, hours,
days or weeks of the injury, in a therapeutically effective amount
and for a time sufficient to restore at least partial mitochondrial
function and alleviate symptoms associated with mitochondrial
dysfunction. The peptides may be administered in a single dose or
in multiple doses over a prolonged period of time suffient to
reduce the symptoms associated with a reduction in mitochondrial
activity, particularly complex I enzyme activity. The subject is
preferably a mammal, e.g., a human.
[0052] Another embodiment of the invention is a method for treating
a subject prior to exposure to a mitochondrial toxin comprising
administering to a subject a pharmaceutically effective amount of a
composition comprising a purified ADNS peptide before exposure to a
mitochondrial toxin. For example the ADNS peptide may be peptide
comprising the amino acid sequence ERNRQAAAANPENSRGK-amide (SEQ ID
NO: 2) or FPLPA-amide (SEQ ID NO: 3); or PPEAPAEDRSL-amide (SEQ ID
NO: 4), or mixtures thereof, or nested fragments thereof, and at
least one of a pharmaceutically acceptable vehicle, excipient, and
diluent. The ADNS peptide may be administered to the subject in an
amount and for a time sufficient to treat the effects of the
mitochondrial toxin. For example, the ADNS peptide(s) may be
administered to the subject within 24 hours, within 12 hours,
within 3 hours, within 1 hour, within 30 minutes, or within 1
minute before being exposed to the toxin or is administered to the
subject concommitantly with exposure to the toxin. In another
embodiment, the ADNS peptides of this invention are administered to
a subject after the subject is exposed to the toxin, preferably
within minutes, hours, days, weeks or months of being exposed to
the toxin, in a therapeutically effective amount for a time
sufficient to restore at least partial mitochondrial function and
alleviate symptoms associated with mitochondrial dysfunction,
particularly a reduction in complex I enzyme activity. The subject
is preferably a mammal, e.g., a human. Alternatively, the
mitochodria, cells containing mitochondria or the subject may be
treated concurrently with exposure to the toxin, for at least for
part of the time that the mitochondria or cells are exposed to the
toxin. In another alternative of the invention, the peptides may be
contacted with the mitochondria, mitochondria-containing cells
after the mitochondria or cells have been exposed to the toxin.
[0053] The small ADNS peptides of this invention are easily within
the range of synthetic production methods, so that the molecules
could be subjected to rigorous structure-activity studies to
optimize pharmacological activities and biostability. In addition,
as the difficulties in delivering GDNF clinically may well be
related to the fact that recombinant GDNF is not properly processed
into active forms, the small ADNS peptides may overcome some of
these difficulties. Finally, small peptides are generally much less
antigenic than proteins and can be synthesized free of the trace
host protein contaminants always present in recombinant
proteins.
[0054] The small ADNS peptides of the present invention include
biologically active synthetic or recombinant ADNS peptides, ADNS
peptides produced from GDNF, biologically active ADNS peptide
variants (including insertion, substitution, and deletion
variants), and chemically modified derivatives thereof. Also
included are biologically active ADNS peptide variants that are
substantially homologous to any one of the ADNS peptides having the
amino acid sequence set forth in SEQ ID NOs:2, 3, or 4. The
peptides of this invention also include fragments of SEQ ID NO: 2,
3 or 4, produced by sequentially truncating single amino acids from
the N-terminus, the C-terminus or both the N- and C-termini of the
sequences to generate shorter and shorter peptide sequences
ultimately generating a 3 amino acid sequence. For example, SEQ ID
NO:2 may be truncated by sequentially truncating single amino acids
from the N-terminal generating shorter and shorter peptide
sequences ultimately leaving the final three amino acids of the
sequence Arg-Ser-Leu, or by sequentially truncating single amino
acids from the C-terminus of SEQ ID NO:2 ultimately leaving the
final three amino acids of the sequence Pro-Pro-Glu, or by
sequentially truncating one amino acid sequentially from both the
N- and C-termini yielding ultimately a Pro-Ala-Glu (PAE) peptide
sequence. These nested fragments may all be amidated.
[0055] The term "biologically active" as used herein means that the
ADNS peptide demonstrates similar neurotrophic properties, but not
necessarily all of the same properties, and not necessarily to the
same degree, as the GDNF protein having the amino acid sequence set
forth in SEQ ID NO:1. The selection of the particular neurotrophic
properties of interest depends upon the use for which the ADNS
peptide is being administered. The ADNS peptides are biologically
active and demonstrate dopaminergic neuron survival characteristics
similar to that demonstrated by the combination of amide peptides
represented by SEQ ID NOs:2, 3, or 4 using the evaluation of
dopamine neuron survival in cultures of newborn rat midbrain
dopamine neurons as an exemplary bioassay, as discussed in the
examples below.
[0056] The term "substantially homologous", as used herein, means a
degree of sequence homology to any one of the ADNS peptides having
the amino acid sequences set forth in SEQ ID NOs:2, 3, or 4 that is
preferably at least 70%, most preferably at least 80%, and even
more preferably at least 90% or even 95%.
[0057] As used herein, the term "ADNS peptide," "peptide amide," or
"amidated peptide" means a peptide comprising the group
--CONH.sub.2 at the C-terminal end. This amidation occurs in vivo,
once the peptides are formed by the enzyme, peptidylglycine
amidating monooxygenase (PAM). The ADNS peptides of the present
invention can be readily obtained in a variety of ways, including,
without limitation, recombinant expression, purification from
natural sources, and/or chemical synthesis. Preferably, the ADNS
peptides can be chemically synthesized by commercial venders. The
ADNS peptides used in the present examples were synthesized using
tBOC chemistry and at a single scale range (which generates a
theoretical crude yield of 500-1,000 mg for a 10-20 mer
respectively), by the Keck Biotechnology Resource Laboratory at
Yale University (New Haven, Conn.).
[0058] ADNS peptide pharmaceutical compositions typically include a
therapeutically effective amount of at least one of a ADNS peptide
represented by SEQ ID NOs:2, 3, and 4 in admixture with one or more
pharmaceutically and physiologically acceptable formulation
materials. Suitable formulation materials include, but are not
limited to, antioxidants, preservatives, coloring, flavoring and
diluting agents, emulsifying agents, suspending agents, solvents,
fillers, bulking agents, buffers, delivery vehicles, diluents,
excipients and/or pharmaceutical adjuvants. For example, a suitable
vehicle may be water for injection, physiological saline solution,
or artificial cerebrospinal fluid (CSF), possibly supplemented with
other materials common in compositions for parenteral
administration. Neutral buffered saline or saline mixed with serum
albumin are further exemplary vehicles.
[0059] The primary solvent in a vehicle may be either aqueous or
non-aqueous in nature. In addition, the vehicle may contain other
pharmaceutically-acceptable excipients for modifying or maintaining
the pH, osmolarity, viscosity, clarity, color, sterility,
stability, rate of dissolution, or odor of the formulation.
Similarly, the vehicle may contain still other
pharmaceutically-acceptable excipients for modifying or maintaining
the stability, rate of dissolution, or rate of release of ADNS
peptide, or for promoting the absorption or penetration of ADNS
peptide across the blood-brain barrier. Such excipients are those
substances usually and customarily employed to formulate dosages
for parenteral administration in either unit dose or multi-dose
form or for direct infusion into the CSF by continuous or periodic
infusion from an implanted pump.
[0060] Once the therapeutic composition has been formulated, it may
be stored in sterile vials as a solution, suspension, gel,
emulsion, solid, or dehydrated or lyophilized powder. Such
formulations may be stored either in a ready to use form or in a
form, e.g., lyophilized, requiring reconstitution prior to
administration.
[0061] The optimal pharmaceutical formulation will be determined by
one skilled in the art depending upon the route of administration
and desired dosage. See for example, Remington's Pharmaceutical
Sciences, 18th Ed. (1990, Mack Publishing Co., Easton, Pa. 18042)
pages 1435-1712 the disclosure of which is hereby incorporated by
reference. The composition may also involve particulate
preparations of polymeric compounds such as polylactic acid,
polyglycolic acid, etc. or into liposomes. Hylauronic acid may also
be used, and this may have the effect of promoting sustained
duration in the circulation. Such compositions may influence the
physical state, stability, rate of in vivo release, and rate of in
vivo clearance of the present proteins and derivatives.
[0062] Other effective administration forms, such as parenteral
slow-release formulations, inhalant mists, orally active
formulations, or suppositories, are also envisioned. Preferred ADNS
peptide pharmaceutical compositions are formulated for parenteral
administration, e.g., intracerebroventricular injection. Such
parenterally administered therapeutic compositions are typically in
the form of a pyrogen-free, parenterally acceptable aqueous
solution comprising ADNS peptide in a pharmaceutically acceptable
vehicle. One preferred vehicle is physiological saline.
[0063] It is also contemplated that certain formulations containing
ADNS peptides are to be administered orally. ADNS peptide which is
administered in this fashion may be encapsulated and may be
formulated with or without those carriers customarily used in the
compounding of solid dosage forms. The capsule may designed to
release the active portion of the formulation at the point in the
gastrointestinal tract when bioavailability is maximized and
pre-systemic degradation is minimized. Additional excipients may be
included to facilitate absorption of ADNS peptide.
[0064] Diluents, flavorings, low melting point waxes, vegetable
oils, lubricants, suspending agents, tablet disintegrating agents,
and binders may also be employed.
[0065] It is further contemplated that formulations containing ADNS
peptides are to be administered nasally. As used herein, nasally
administering or nasal administration includes administering the
formulation containing ADNS to the mucous membranes of the nasal
passage or nasal cavity of the patient. Formulations for nasal
administration include a pharmaceutically effective amount of the
peptides prepared by well-known methods, to be administered, for
example, as a nasal spray, drop, suspension, gel, ointment, cream
or powder. Administration of the ADNS-containing formulation may
also take place using a nasal tampon, or nasal sponge.
[0066] The ADNS peptides may be administered parenterally via a
subcutaneous, intramuscular, intravenous, transpulmonary,
transdermal, intrathecal or intracerebral route. ADNS peptides that
do not cross the blood-brain barrier may be given directly
intracerebrally or otherwise in association with other elements
that will transport them across the barrier. It is preferred that
the ADNS peptide is administered intracerebroventricularly or into
the brain or spinal cord subarachnoid space. ADNS peptides may also
be administered intracerebrally directly into the brain parenchyma.
Slow-releasing implants in the brain containing the neurotrophic
factor embedded in a biodegradable polymer matrix can also deliver
ADNS peptides. ADNS peptides may be administered extracerebrally in
a form that has been modified chemically or packaged so that it
passes the blood-brain barrier, or it may be administered in
connection with one or more agents capable of promoting penetration
ADNS peptide across the barrier. For example, a conjugate of NGF
and monoclonal anti-transferrin receptor antibodies has been shown
to be transported to the brain via binding to transferrin
receptors. To achieve the desired dose of ADNS peptide, repeated
daily or less frequent injections may be administered, or truncated
ADNS peptide may be infused continuously or periodically from a
constant- or programmable-flow implanted pump. The frequency of
dosing will depend on the pharmacokinetic parameters of ADNS
peptide as formulated, and the route of administration.
[0067] Regardless of the manner of administration, the specific
dose is typically calculated according to body weight or body
surface area. For diseases involving the brain, the specific dose
is typically calculated according to the approximate brain weight
of the subject, which also may be estimated based on body weight or
body surface area. Further refinement of the calculations necessary
to determine the appropriate dosage for treatment involving each of
the above mentioned formulations is routinely made by those of
ordinary skill in the art, especially in light of the dosage
information and assays disclosed herein. Appropriate dosages may be
ascertained through use of the established assays for determining
dosages utilized in conjunction with appropriate dose-response
data. The final dosage regimen involved in a method of treating a
specific condition will be determined by the attending physician,
considering various factors which modify the action of drugs, e.g.,
the age, condition, body weight, sex and diet of the subject, the
severity of any infection, time of administration and other
clinical factors.
[0068] ADNS peptides of the present invention may also be employed,
alone or in combination with other growth factors in the treatment
of nerve disease. For example, ADNS peptides may be used in
treating some forms of nerve disease in combination with nerve
growth factor. In addition, other factors or other molecules,
including chemical compositions, may be employed together with ADNS
peptides. In the treatment of Parkinson's disease, it is
contemplated that ADNS peptide be used by itself or in conjunction
with the administration of Levodopa, wherein the ADNS peptide would
enhance the production of endogenous dopamine and the neuronal
uptake of the increased concentration of dopamine.
[0069] As stated above, it is also contemplated that additional
neurotrophic or neuron nurturing factors will be useful or
necessary to treat some neuronal cell populations or some types of
injury or disease. Other factors that may be used in conjunction
with ADNS peptides include, but are not limited to: mitogens such
as insulin, insulin-like growth factors, epidermal growth factor,
vasoactive growth factor, pituitary adenylate cyclase activating
polypeptide, interferon and somatostatin; neurotrophic factors such
as brain derived neurotrophic factor, neurotrophin-3,
neurotrophin-4/5, neurotrophin-6, insulin-like growth factor,
ciliary neurotrophic factor, acidic and basic fibroblast growth
factors, fibroblast growth factor-5, transforming growth
factor-.beta., cocaine-amphetamine regulated transcript (CART) and
mature GDNF; and other growth factors such as epidermal growth
factor, leukemia inhibitory factor, interleukins, interferon, and
colony stimulating factors; as well as molecules and materials
which are the functional equivalents to these factors.
[0070] It is envisioned that the continuous administration or
sustained delivery of a ADNS peptide may be advantageous for a
given treatment. While continuous administration may be
accomplished via a mechanical means, such as with an infusion pump,
it is contemplated that other modes of continuous or near
continuous administration may be practiced. For example, chemical
derivatization may result in sustained release forms of the protein
which have the effect of continuous presence in the blood stream,
in predictable amounts, based on a determined dosage regimen. Thus,
ADNS peptides of the present invention include ADNS peptides
derivatized to effectuate such continuous administration.
[0071] ADNS peptide cell therapy, e.g., intracerebral implantation
of cells producing ADNS peptides, is also contemplated. This
embodiment of the present invention may include implanting into
subject's cells which are capable of synthesizing and secreting a
biologically active form of the ADNS peptides of the present
invention. Such ADNS peptide producing-cells may be cells which do
not normally produce a neurotrophic factor but have been modified
to produce ADNS peptides, or they could be cells whose ability to
produce GDNF has been augmented by transformation with a
polynucleotide suitable for the expression and secretion of ADNS
peptides. In order to minimize a potential immunological reaction
in subjects, it is preferred that the cells be of human origin.
[0072] Implanted cells may be encapsulated to avoid infiltration of
the cells into brain tissue. Human or non-human animal cells may be
implanted in subjects in biocompatible, semi-permeable polymeric
enclosures or membranes to allow release of an ADNS peptide, but
that prevent destruction of the cells by the subject's immune
system or by other detrimental factors from the surrounding tissue.
Alternatively, the subject's own cells, transformed ex vivo to
produce ADNS peptides, could be implanted directly into the subject
without such encapsulation.
[0073] The methodology for the membrane encapsulation of living
cells is familiar to those of ordinary skill in the art, and the
preparation of the encapsulated cells and their implantation in
subjects may be accomplished. See for example, U.S. Pat. Nos.
4,892,538; 5,011,472; and 5,106,627, the disclosures of which are
hereby incorporated by reference. A system for encapsulating living
cells is also described in PCT Application WO 91/10425 of Aebischer
et al., specifically incorporated herein by reference. See also,
PCT Application WO 91/10470 of Aebischer et al.; Winn et al.,
Exper. Neurol., 113:322-329, 1991; Aebischer et al., Exper.
Neurol., 111:269-275, 1991; and Tresco et al., ASAIO, 38:17-23,
1992, the disclosures of which are hereby incorporated by
reference.
[0074] ADNS peptide gene therapy in vivo is also envisioned,
wherein a nucleic acid sequence encoding an ADNS peptide is
introduced directly into the subject. For example, a nucleic acid
sequence encoding an ADNS peptide is introduced into target cells
via local injection of a nucleic acid construct with or without an
appropriate delivery vector, such as an adeno-associated viral
vector. Alternative viral vectors include, but are not limited to,
retrovirus, adenovirus, herpes simplex virus and papilloma virus
vectors. Physical transfer may be achieved in vivo by local
injection of the desired nucleic acid construct or other
appropriate delivery vector containing the desired nucleic acid
sequence, liposome-mediated transfer, direct injection (naked DNA),
receptor-mediated transfer (ligand-DNA complex), or microparticle
bombardment (gene gun). It should be noted that the ADNS peptide
formulations described herein may be used for veterinary as well as
human applications and that the term "subject" should not be
construed in a limiting manner. In the case of veterinary
applications, the dosage ranges should be the same as specified
above.
[0075] As a means of further characterizing the ADNS peptides of
the present invention, antibodies can be developed which bind to
the ADNS peptides. One of ordinary skill in the art can use
well-known, published procedures to obtain monoclonal and
polyclonal antibodies, or recombinant antibodies, which
specifically recognize and bind to the various ADNS peptides of the
present invention.
[0076] Other aspects and advantages of the present invention will
be understood upon consideration of the following illustrative
examples. The examples are not to be construed in any way as
limiting the scope of this invention.
EXAMPLES
Example 1: BLAST Analysis
[0077] The three hypothetical precursor segments
(RRERNRQAAAANPENSRGKGRR (SEQ ID NO: 15); FPLPAGKR (SEQ ID NO: 8);
and KRPPEAPAEDRSLGRR (SEQ ID NO: 7); see FIG. 3) were subjected to
BLAST searches for short, nearly identical sequences.
RRERNRQAAAANPENSRGKGRR (SEQ ID NO: 15) is present in GDNF splice
forms 1 and 2. There are some sequence variations by species, but
consensus post-translational processing signals are maintained
across species. FPLPAGKR (SEQ ID NO: 8) was found to be invariant
in the available GDNF splice form 1 sequences, but does not occur
in splice forms 2 and 3. KRPPEAPAEDRSLGRR (SEQ ID NO: 7) scored
hits in splice form 1, but not in the other GDNF splice forms.
There are some sequence variations by species, but consensus
processing signals are maintained across species. Thus, these ADNS
peptides are unique to mostly splice form 1 of GDNF and not other
splice forms of the pre pro GDNF.
Example 2: Synthesis of ADNS Peptides
[0078] Three peptides, designated GER9263, GER9264, and GDR9265
(see Table 1, below) were synthesized by Keck Biotechnology
Resource Laboratory, Yale University New Haven, Conn. Synthetic
peptides can be made routinely up to 40 residues and often,
depending on sequence, up to 70 residues by this facility. All
peptides were separated and purified on a preparative C-18 or C-4
RP-HPLC system and delivered as a lyophilized material. Yields for
normal peptides under 40 residues were "guaranteed" at 50 mg or
more and at 90+% purity. Yields and purity are often higher,
varying with the peptide sequence and length. All peptides made in
the Keck facility at the 0.5 mmole scale are done by tBOC chemistry
and at a single scale range (which generates a theoretical crude
yield of 500-1,000 mg for a 10-20 mer respectively). The purified
peptides were characterized by analytical RP-HPLC, amino acid
analysis, and FAB mass spectroscopy.
TABLE-US-00001 TABLE 1 ADNS peptides Peptide Sequence GER9263
ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2) GER9264 FPLPA-amide (SEQ ID
NO: 3) GDR9265 PPEAPAEDRSL-amide (SEQ ID NO: 4)
Example 3: Dopaminergic Activity of ADNS Peptides in Fischer 344
Rats
[0079] Experiments were performed to test the effects of the three
ADNS peptides (GER9263, GER9264, and GDR9265) on dopaminergic
activity in normal young adult male Fischer 344 rats. The peptides
were combined in a 1:1:1 ratio. There were three test groups with
six animals per group: vehicle (citrate buffer), vehicle plus 30
peptide mixture, and vehicle plus 100 .mu.g peptide mixture. The
vehicle or vehicle plus peptide solutions were steriotaxically
injected in equal portions into two sites each in the right
substantia nigra.
[0080] One month after drug administration, the basal levels of
dopamine and dopamine metabolites were measured by microdialysis in
the right striatum. Potassium and amphetamine evoked release of
dopamine were also evaluated.
[0081] While basal levels of dopamine were not significantly
altered in the striatum, average K.sup.+-evoked release of dopamine
increased by over 50% (FIG. 4). Average amphetamine-evoked release
was more variable, but ranged from about 30% for 100 .mu.g to about
45% for 30 .mu.g. While basal dopamine levels were about the same
in all three groups, basal metabolite levels were elevated. As
shown in FIG. 5, the major metabolites 3,4-Dihydroxy-Phenylacetic
Acid (DOPAC) and Homovanillic Acid (HVA) were increased by about
40% (DOPAC) and 20-40% (HVA), depending upon the dose.
Example 4: ADNS Peptides and Response to CNS Delivery in an Aged
Rhesus Monkey
[0082] A study was performed demonstrating that a mixture of three
ADNS peptides (GER9263, GER9264, and GDR9265 combined in a 1:1:1
ratio) exerts pharmacological effects on CNS nigral dopamine
neurons in an aged rhesus monkey similar to those produced by GDNF.
Marked increases of 68-125% in stimulus-evoked dopamine release
were measured in the putamen by in vivo microdialysis. Motor speed,
as measured in fine motor hand movements, increased by up to 58%,
into the range of young adult monkeys. General body movements
increase by 38%, indicating much higher activity levels. The
effects from unilateral treatment were long-lasting (for at least
one month) and bilateral, similar to those resulting from GDNF
treatment. Histopathological analysis of the injection sites in the
substantia nigra revealed only mild, circumscribed pathology from
the peptide injections. The pharmacological effects of ADNS
peptides on upregulating nigrostriatal dopamine system functions
are extraordinary and suggest their potential therapeutic use for
the treatment of Parkinson's disease and age-associated movement
dysfunctions.
[0083] The ADNS peptides tested in this Example are three amidated
peptides predicted to exert potent biological effects similar to
those of Glial Cell Line-Derived Neurotrophic Factor (GDNF). The
effects of GDNF on CNS dopamine neurons fall generally into three
categories: pharmacological upregulation of dopaminergic activity,
neuronal regeneration and neuroprotection. This study was designed
to assess the pharmacological effects of ADNS peptides on
substantia nigra dopamine neurons in the nonhuman primate brain. It
was previously shown that CNS delivery of GDNF increases
stimulus-evoked dopamine release in aged rhesus monkeys (Grondin et
al., 2003). In addition, behavioral correlates of increased
dopaminergic activity were recorded in these animals, improved
motor functions and increased motor speed. The present study was a
case report on one aged monkey that received a 100 .mu.g injection
of ADNS peptides into the substantia nigra of the brain and was
followed for 30 days. Motor speed was measured weekly using an
automated movement analysis panel (MAP) and EthoVision, a video
tracking program. Movement features were rated weekly using a
nonhuman primate clinical rating scale (Zhang, Z. et al., J
Gerontology: Biol. Sci. 55A:B473-B480, (2000)). Stimulus-evoked
dopamine release was analyzed by microdialysis at the 30 day time
point. The animal was then euthanized and the brain recovered for
histopathological analysis.
[0084] Methods Used for Studying ADNS Peptides
[0085] Animal:
[0086] A thirty-four year old female rhesus monkey (1D# NJ05)
weighing 7 kg was used. The animal was diagnosed as having an
inoperable mammary tumor, with the attending veterinarian
suggesting that the monkey be placed in a terminal study and
euthanized for humanitarian reasons. The animal was maintained on a
12-hour light/12-hour dark cycle and housed individually in a cage
measuring 9 square feet, with an elevated perch, front access doors
and side rear access doors connecting the housing cage to an
adjacent activity module. The diet consisted of certified primate
biscuits given in the morning (7:30 AM), and supplemented daily in
the afternoon (1:30 PM) with fresh fruit or vegetables. Water was
available ad libitum.
[0087] All procedures were conducted in the Laboratory Animal
Facilities of the University of Kentucky, which are fully
accredited by the Association for Assessment and Accreditation of
Laboratory Animal Care. Veterinarians skilled in the health care
and maintenance of nonhuman primates supervised all animal
care.
[0088] MRI Imaging:
[0089] Magnetic resonance images (MM) were obtained on a I 0.5T
clinical imager (Siemens Magnetom Vision) using a standard cross
polarized extremity coil. After being sedated with ketamine
hydrochloride (.about.20 mg/kg; i.m.) plus atropine sulfate
(.about.0.04 mg/kg; i.m.), the animal was anesthetized with sodium
pentobarbital (.about.10 mg/kg; i.v.) and imaged to provide
stereotaxic coordinates for peptide delivery. The animal's head was
positioned in the extremity coil using an MRI compatible
stereotaxic head frame. This frame kept the animal's head level and
immobilized at the center of the radio frequency coil using ear and
mouth bars. An initial set of coordinates was taken using the
earbars, toothbar and a zeroing bar targeted to the gum line
between the two upper middle incisors to allow replication any time
the animal was replaced in the stereotaxic apparatus.
[0090] The coil/frame assembly was then positioned to place the
animal's head at magnet isocenter. Sets of T1-weighted 3D-FLASH
images were collected for determination of the brain coordinates
(TR/TE=22/9 ms; FA=35.degree.; FOV=96.times.96.times.90 mm;
Matrix=128.times.128.times.90; Nacq=2; TA=6 min 48 sec). All images
were acquired as coronal slices relative to the brain.
Antero-posterior, lateral and vertical coordinates for stereotaxic
surgery were derived from the T1-weighted coronal brain images. The
interaural line was identified on the scans by modified earbars
containing Vitamin E. This provided a precise reference-point,
which allowed for anteroposterior measurements to the target.
Lateral measurements were determined by measuring the distance from
the sagittal sinus/third ventricle to the target site. Vertical
measurements were determined from the surface of the brain to the
target at the lateral coordinate.
[0091] Surgery:
[0092] Following sedation with ketamine hydrochloride (.about.20
mg/kg; i.m.) plus atropine sulfate (.about.0.04 mg/kg; i.m.), the
animal was intubated via the orotracheal method and intravenous
lines secured. Then, the animal was anesthetized with isoflurane
(1-3%) and placed in an MRI compatible Kopf stereotaxic apparatus
in a ventral-lateral position as per the coordinates previously
(see Anatomical MRI above). The animal was maintained on a heated
blanket and had cardiac and respiratory parameters monitored during
the procedure, which was carried out using sterile field
conditions. Coordinates for peptide injections were determined by
MRI prior to the surgery as described above. After being shaved,
the scalp area was cleaned using antiseptic procedures with sterile
4.times.4 sponges soaked in Betadine.RTM. surgical scrub followed
by 70% isopropyl alcohol. This procedure was repeated. After the
alcohol dried, Betadine.RTM. prep was applied and the animal was
covered with sterile drapes. Then, an incision was made through the
scalp and the skin and muscles overlying the skull were reflected.
Small holes were drilled in the skull directly over the target
area. The overlying meninges were removed to expose the surface of
the brain.
[0093] A 1.0 mg/ml concentration of the three-peptide mixture in
citrate buffer was used. It was sterilized by filtration prior to
injection Using MRI-guided procedures, a 27G needle coupled to a
Hamilton syringe containing 100 .mu.l (i.e. 100 .mu.g) of the
peptide mixture was lowered in the right rostral SNc (AP: 11, L: 5,
DV: 30 from surface of the brain). A volume of 50 .mu.l was
delivered using a nanopump at a rate of 1 .mu.l/min. This was
followed by a 20 min waiting period before retracting the needle
out of the brain (1 mm/min). The needle/syringe assembly was then
moved 1 mm caudally and 0.5 mm laterally and lowered into the more
caudal SNc (AP: 10, L: 5.5, DV: 29 from surface of the brain). This
was followed by a 20 min waiting period before retracting the
needle out of the brain (1 mm/min). After completion of the
injections, the scalp incision was sutured over the exposed areas
per normal procedures and the animal was given an analgesic
(buprenorphine, 0.01 mg/kg, i.m.). Vital signs were monitored until
the animal awakened, at which point the animal was covered with
warm blankets and taken back to its cage and monitored until it was
ambulatory.
[0094] Behavioral Tests:
[0095] To assess changes in motor functions, the animal was
videotaped prior to injecting the peptide mixture, and weekly after
the injection for four weeks. The videotaping cage measured 28
inW.times.32 inH.times.32 inD, had a white background wall and a
clear Lexan window permitting videotaping. The videotaping cage was
illuminated by two 48 in-long fluorescent lights located 30 in
above. Water (via a cage attached bottle) was available ad libitum
throughout the session. The animal was fed fruit or vegetables
after completion of data acquisition and upon return to its home
cage.
[0096] Beginning at 1 PM, a technician entered the room and placed
small food items (e.g. gummy bears) on the ledge of the cage to
elicit the animal to stand-up and reach out for the food. Then, the
animal was videotaped for 30 minutes with no one in the room.
Following this 30-minute videotaping period, the technician
re-entered the room, stopped recording and attached a non-wired
version of the monkey Movement Analysis Panel (MAP, see below) to
the doorway of the cage for a hand retrieval test. Five to six
preferred small food items (e.g. miniature marshmallows) were
placed on each side of the panel. The animals was given 10 minutes
(default time) to retrieve the food items, at which point the
tester re-entered the room and stopped recording. This portion of
the session was videotaped, with a focus on the hands. Starting at
2 PM, the same procedures described above were repeated. At the end
of the testing session, the animal was returned to its home
cage.
[0097] As described above, standardized videotaping procedures were
conducted pre- and post-treatment. Behavioral parameters associated
with motor function were scored from coded videotapes from 0
(normal) to 3 (severe disability) in the following categories:
rigidity, bradykinesia, posture, balance, tremor, and hand
dexterity (see Zhang et al., 2000). Rigidity is defined as a
decrease in limb extension and/or use. Motor dysfunctions were
rated in half-point increments by an experienced rater.
[0098] Distance traveled (cm) was quantified from 8-mm videotapes
(SONY P6-120MPL) using a commercially available video tracking
system EthoVision Pro (version 2.3, Noldus Information Technology,
Asheville, N.C.) coupled to a SONY Digital 8 video cassette
recorder. This system runs on a Pentium based computer with a frame
grabber card (PICOLO, Belgium), so that the analog video signal
coming from the video cassette recorder is digitized and
transferred to the computer. A window on the computer screen
directly displays the video image, and the boundaries within which
tracking took place were defined by accurately tracing the outline
of the cage in the video image, in addition, two zones were
outlined, so that the overall activity measured in the entire cage
could be analyzed in terms of vertical (top half) or horizontal
(bottom half) activity. As described above, the animal was
videotaped for 60-minute periods, pre- and post-treatment, and the
video tracks were analyzed at a rate of 6-sample/sec. For every
sample, the cage was scanned and the position of the tracked animal
was determined by using a gray scale detection method (brightness).
This entails calibrating the software to distinguish the
dark-colored animal from the background, which is then defined as
all other pixels. The back wall of the cage was painted white to
provide a background with a maximum degree of contrast with the
dark-colored primate. This automated method relies on determining
the position of the center of mass of the animal in the cage, and
the resultant x-y coordinates extracted as a function of time are
used for calculating the movement pattern during the observation
period. These coordinates were subsequently related to actual
spatial measures by calibrating the software to the dimension
(width) of the cage, the distance traveled by the animal were
calculated in centimeters instead of pixels.
[0099] Movement Analysis Panel (MAP):
[0100] In addition, fine/hand motor movement times in retrieving
food items from a platform level placed in a receptacle chamber
were measured using an automated clear Lexan MAP attached to the
door opening of the home cage (see Gash, D. M. et al. J. Neurosci
Methods 89:111-117, (1999) and Zhang et al., 2000). The receptacle
chamber is divided into left and right halves, and is accessible on
each side through two portals (armhole portal and receptacle
portal). Movement times were measured by arrays of three
photodiodes around each portal that automatically relayed to the
computer when one or more beams were broken by passage of the
monkey's arm/hand. Testing was conducted in the afternoon, prior to
injecting the peptide mixture, and weekly thereafter for four
weeks. Fresh fruit and vegetables were given to the animal after
completion of the testing session. A day's testing session
consisted of twelve trials, six on each side alternating between
the right and left hand.
[0101] Microdialysis Studies:
[0102] The animal underwent bilateral putamenal microdialysis one
month post ADNS peptide injection. Using the method described
below, in vivo microdialysis procedures had also been conducted
previously in the right striatum of the same animal (date: 2/10/04;
coordinates: AP:20.5 mm, L:10.2 mm, DV from cortex:21 mm).
[0103] Following normal MRI-guided stereotactic procedures (see
Surgical procedures for ADNS peptide injection), custom-made CMA/11
dialysis probes with a membrane length of 3 mm and diameter of 0.24
mm (CMA Microdialysis, North Chelmsford, Mass.) were positioned (1
mm/min) bilaterally in the putamen (AP:20 mm, L:10.5 mm, DV from
cortex:20 mm). Probes were perfused continuously at a rate of 1.2
.mu.l/min with artificial cerebrospinal fluid using a computerized
multisyringe pump (World Precision Instruments). Microdialysate
fractions were collected at 30 min intervals.
[0104] Following a 1-hour application of artificial cerebrospinal
fluid to collect baseline fractions, excess potassium (100 mM KCl,
47.7 mM NaCl) was then included in the perfusate for a single
30-min fraction (t.sub.0-t.sub.30). Two hours later 250 .mu.M
amphetamine was included in the perfusate for a single 30-min
fraction (t.sub.1-t.sub.150). Three additional fractions were
collected after discontinuing amphetamine administration
(t.sub.180-t.sub.240). The incision was then closed as per normal
surgical procedures. Microdialysate fractions were analyzed using
standard high performance liquid chromatography procedures coupled
with electrochemical detection.
[0105] Tissue Collection Procedures:
[0106] Tissue biopsies were collected for possible future use. At
the end of the dialysis session, the animal was immediately
euthanized. The deeply anesthetized animal (2 ml pentobarbital,
i.v.) was transcardially perfused with heparinized ice-cold saline
(6 L). Then, the brain was removed quickly, and dropped into a
container of cold saline, which was placed on wet ice and taken
back to the laboratory. Using an ice-cold mold, the brain was
sectioned into 4-mm coronal slabs, rostral of the midbrain.
[0107] Multiple tissue punches were taken bilaterally from frozen
4-mm thick coronal tissue sections using a 14G biopsy needle in the
caudate nucleus (n=18 per side, tissue slabs #3, #4 and #5),
putamen (n=18 per side, tissue slabs #4, #5, #6), nucleus accumbens
(n=7 per side, tissue slabs #3 and #4) and globus pallidus (n=5 per
side, tissue slabs #6). Separate needles were used for the right
and left (green tape) hemisphere. All punches were rapidly
transferred to pre-weighed storage tubes, weighed once more, and
stored at -80.degree. C. Pictures of the punched slabs were taken
to document the punching pattern, and then they were stored at
-80.degree. C.
[0108] The midbrain was taken out as a block, which included the
cerebellum, and post-fixed for quantitative immunocytochemistry of
substanita nigra dopamine neurons and TH+ processes. To do so, the
midbrain was immediately immersed in 4% paraformaldehyde in 0.1 M
phosphate buffer (pH 7.4) at 4.degree. C. for three days and
transferred to 15% sucrose solution until saturated for sectioning.
Then, a series of 40 .mu.m-thick coronal sections were cut on a
frozen sliding microtome. One out of every 12th adjacent sections
was processed for cresyl violet (Nissl) and hemotoxylin and eosin
(H & E) staining. Also, 1/12th adjacent sections were processed
for the following staining: a) 1:1000 mouse anti-glia fibrillary
acidic protein (GFAP) antibody for astrocytes, b) 1:200 mouse
anti-HLA-DR antibody for reactive microglia, and c) 1:1000 mouse
anti-tyrosine hydroxylase (TH) antibody for dopaminergic neurons
(see Ai et al., 2003).
[0109] Effects of ADNS Peptides on an Aged Rhesus Money
[0110] The animal recovered without problems from peptide delivery
into the right substantia nigra. No clinically observable abnormal
behaviors (e.g. auto-mutilation, stereotypic movements, dyskinesia,
vomiting) were noted throughout the 30-day study.
[0111] As described above, standardized videotaping procedures were
conducted pre- and post-treatment to assess changes in motor
functions from coded videotapes. Prior to injecting the
three-peptide mixture into the right substantia nigra, the animal
was given a cumulative score of 3.25 points on the rating scale
(See Table 2). Although the effect was variable, this score
improved (the lower the score, the better the movement functions)
by over 30% (i.e. 1 point) by the fourth week of the study.
Similarly, distance traveled (cm) measured over weekly 60-minute
periods using the automated video-tracking system (EthoVision)
improved up to 38% by the fourth week post treatment versus
baseline locomotor activity (from 7064 cm to 9780 cm). Last but not
least, MAP performance times for left hand motor were 56% faster by
week four post peptide treatment (from 0.81 sec to 0.36 sec). Right
hand performance times were already faster than the left
pre-peptide treatment. They further improved in the 4 weeks
post-treatment, with performance times 14% faster (from 0.36 sec to
0.31 sec).
[0112] In vivo microdialysis was used to investigate the dynamics
of dopamine release in the basal ganglia. Measurements were carried
out in the right putamen four weeks post peptide treatment (see
FIGS. 7A and B). In particular, FIG. 7 shows the results of
potassium (K+) and d-amphetamine (d-AMPH) evoked release of
dopamine measured in the right putamen of NJO5 using microdialysis
to collect samples for neurochemical analysis. FIG. 7A shows the
first recordings made Feb. 10, 2004, several years prior to the
ADNS peptide study. In aging monkeys, dopamine evoked release of
dopamine to K+ and d-AMPH normally decreases with increasing age.
FIG. 7B shows the second set of recordings made thirty days after
ADNS peptide injections into the right substantia nigra on Apr. 27,
2006. K+ evoked release was increased from the 2004 reading from
36.5 nM to 82 nM. D-AMPH evoked release of dopamine increased from
74 nM to 125 nM after ADNS peptide administration. Thus, in
comparison to measurements recorded under similar conditions two
years earlier in the same animal, potassium-evoked overflow of
dopamine was increased by 125% at 30 days post ADNS peptide
administration (from 36.5 nM to 82 nM). Similarly,
amphetamine-induced overflow of dopamine was increased by 68%
compared to measurements recorded two years earlier (from 74 nM to
125 nM).
[0113] Basal levels of dopamine and dopamine metabolites in the
striatum were determined from measurements in the microdialysates
prior to potassium and amphetamine stimulation. Basal dialysate
levels of dopamine and HVA showed small changes from the baseline
levels two years earlier (Table 2). However, basal levels of
extracellular DOPAC were increased by 230% at thirty days post
peptide injection compared to the earlier baseline measures (Table
3).
[0114] The histopathological response to the injection of peptides
in the nigral region was mild (see FIGS. 8 and 9). In FIG. 8, one
of the injection sites (arrow) is shown using standard
histochemical techniques for Nissl staining and hematoxylin and
eosin (H & E) staining. Immunostaining was conducted to assess
the response of astrocytes (GFAP positive cells) and microglia
(HLA-DR positive cells) to the injections. In FIGS. 8A and B, this
injection site (arrow) was just dorsal to the substantia nigra,
pars compacta (SNc). While there is an evident response at the
injection site and a smaller satellite area (*) of reactivity
dorsal to the main area, the injury response is very circumscribed.
FIG. 8C shows that reactive astrocytosis, as assessed by GFAP
positive reactivity around the needle track, is minimal,
approximately that expected from a needle tract injury alone. In
FIGS. 8D and E, the injury response appears similar using H & E
to that seen with Nissl. The injury response is localized and does
not seem to involve adjacent cells. Reactive microglia (HLA-DR+
cells) are a prominent constituent of the injury response (arrow
and *, FIG. 8F). (In FIG. 8, Cerebral peduncle=CP; Substantia nigra
reticulatia=SNr; Ventral Tegmental Area=VTA. Scale bars are
included in each photomicrograph.) The injection site showed
reactive cells in an area about 200 .mu.m wide by 400 .mu.m long in
Nissl-stained and H & E-stained sections (FIGS. 8 A, B, D and
E). The response consisted of activated microglia (HLA-DR positive
cells, FIG. 8F). The absence of pronounced GFAP immunostaining
(FIG. 8) indicated that the injection did not stimulate a glial
reaction.
[0115] The substantia nigra pars compacta (SNc) containing the
population of dopamine neurons that degenerates in Parkinson's
disease is evaluated in the series of photomicrographs set forth in
FIG. 9. In FIG. 9A, Nissl-rich neurons (arrowheads) adjacent to the
peptide injection site (*) appear normal with prominent nuclei
evident in the nucleus of some cells. Nissl staining corresponds to
the presence of rough endoplasmic reticulum in the cytoplasm and
indicates cells actively synthesizing protein. The H & E
stained section in FIG. 9B also shows neurons with normal features
(arrowheads) adjacent to the injection site (*). FIG. 9C shows that
there are only a few scattered activated microglia (arrowheads
showing HLA-DR positive cells) in the SNc. Large numbers would
indicate ongoing pathological processes. Tyrosine hydroxylase (TH)
is the rate-limiting enzyme in dopamine synthesis. The TH positive
cells shown in FIG. 9D are dopamine neurons. Their size and
exuberant expression of TH positive processes are indicative of
healthy, active cells. Scale bars are included in each
photomicrograph. Dopamine neurons in the substantia nigra appeared
to be normal (FIG. 9). Tyrosine hydroxylase immunostaining (FIG.
9D) revealed large dopamine neuron perikarya (cell bodies) with
extensive neuritic processes. Along with the Nissl and H & E
stained sections (FIGS. 9 A and B), the nigral cells showed
features characteristic of healthy neurons. A few activated
microglia (HLA-DR positive cells, FIG. 9C) were present in the
nigral region, a typical feature of this brain region in healthy
aged monkeys. Large numbers of activated microglia would be
indicative of an ongoing disease process.
[0116] The subject in this study was a very old rhesus monkey, 34
years old. One year for a rhesus monkey is roughly equivalent to
three years of human life, making this animal equivalent to a 100
year old person. The monkey was used in this study because it had a
terminal disease, mammary cancer. The closest comparable monkeys in
an earlier study treated with GDNF were 22-24 years old (Grondin et
al., 2003). They received infusions of GDNF into the brain for 24
weeks while NJO5 had a single injection of an ADNS peptide mixture
and was monitored for one month. Despite the differences, many of
the responses were comparable to those seen to GDNF. NJO5 motor
performance times on the MAP improved within four weeks on both the
right (14%) and left (56%) sides. The improved motor speeds
approached the speeds of aged monkeys receiving GDNF and those of
normal young adult animals. Consistent with increased motor speed,
general locomotor activity was increased by 38% by four weeks of
treatment in NJO5. There were neurochemical changes in NJO5's brain
along with the behavioral improvements. Both potassium- and
amphetamine-evoked release were increased (125% and 68%,
respectively) in the putamen in comparison to pretreatment levels.
This was similar to the increased evoked release of dopamine in
response to the same stimulants in aged rhesus monkeys treated with
GDNF (Grondin et al., 2003). Basal dialysate levels of dopamine,
HVA and DOPAC showed high variability, but were not significantly
changed in aged GDNF recipients. NJO5's basal dopamine and dopamine
metabolite levels were in the same range as the GDNF and
vehicle-treated old animals. The only dramatic change seen in this
animal was in DOPAC levels, which increased over three-fold post
ADNS peptide treatment. The significance of this response is that
it reflects higher levels of dopamine metabolism in the
striatum.
[0117] Histopathology was much less extensive than the damage in
the same region from the infusion of GDNF (see Gash, D. M. et al.,
Ann Neurol 58(2):224-33 (2005)). The dopamine neurons in the
substantia nigra appeared healthy, with numerous neuritic
processes.
TABLE-US-00002 TABLE 2 Changes in motor functions post ADNS
peptides delivery into the right substantia nigra. The reduction in
the disability score means that the motor functions such as walking
and balance were improving. The locomotor activity level increases
by week four also reflect that the animal was increasing the time
and distance in walking. The Movement Analysis Panel (MAP) scores
demonstrate much faster hand fine motor movements by week 4 after
treatment. Disability Locomotor Left Map Right MAP Score Activity
Times times (pts)/% (cm)/% (sec)/% (sec)/% Treatment baseline
baseline baseline baseline Baseline 3.25 7064 0.81 0.36 Week 1
2.00/-38% 8422/+19% 0.86/+6% 0.45/+25% Week 2 2.00/-38% 7136/+1%
1.09/+35% 0.39/+8% Week 3 2.50/-23% 6368/-10% 0.75/-7% 0.34/-6%
Week 4 2.25/-31% 9780/+38% 0.36/-56% 0.31/-14%
TABLE-US-00003 TABLE 3 Changes in basal dialysate levels of
dopamine and dopamine metabolites in the right putamen, 30 days
post ADNS peptide delivery into the right substantia nigra. The
large increase in levels of the dopamine metabolite DOPAC indicate
increase dopaminergic activity. As the enzyme (monoamine oxidase B)
for metabolizing dopamine to DOPAC is on the outer membrane of
mitochondria, it also reflects either more active mitochondria and
increased numbers of mitochondria. Hemisphere Dopamine (nM) HVA
(nM) DOPAC (nM) Pre-peptides 5.6 5033 127 Post-peptides 4.9 4191
419
Example 5: Materials and Methods
[0118] The following materials and methods were used in the
following examples.
[0119] Materials: Unless otherwise stated, all cell reagents and
assays were purchased from Invitrogen. All other materials and
chemicals are reagent grade.
[0120] DNSP-17 (GER 9263), DNSP-5 (GER 9264), DNSP-11 (GER 9265),
and Biotinylated DNSP-11: DNSP-17 (sequence:
ERNRQAAAANPENSRGK-amide (SEQ ID NO: 2)), DNSP-5 (sequence:
FPLPA-amide (SEQ ID NO: 3)): DNSP-11 (sequence: PPEAPAEDRSL-amide
(SEQ ID NO: 4)) and biotinylated DNSP-11 (bDNSP-11; sequence:
biotin-PPEAPAEDRSL-amide (SEQ ID NO: 4)) were synthesized and
RP-HPLC purified to >98% by AC Scientific (Duluth, Ga.) and the
W.M. Keck Foundation Biotechnology Resource Laboratory at Yale
University. Peptides were characterized for purity and correct
sequence by MALDI-TOF LC-MS and Edman degradation. DNSP-11 was
determined to be stable, in vitro, at a variety of experimentally
relevant concentrations and temperatures, including 37.degree. C.
in sterile pH 5 citrate buffer for 31 days.
[0121] Tissue preparation for DNSP-11 Staining in Substantia Nigra
at Postnatal Day (PN10): Tissue was prepared from SD pups. Brains
were rinsed in Dulbecco's Phosphate Buffered Saline (DPBS, Gibco),
and submerged in 4% paraformaldehyde pH 7.4 for 48 hours. Following
submersion in 30% sucrose, brains were sectioned coronally (40
.mu.m) and stored in cryoprotectant solution at -70.degree. C.
until processed for immunohistochemistry.
[0122] DNSP-11 treatment of Mesencephalic Cells: Timed pregnant SD
rats (Harlan) were used to obtain the ventral mesencephalon from
E14 fetuses. The dissected tissue was collected in cold
Neurobasal.TM. medium and rinsed twice with cold Dulbecco's PBS.
The cells were chemically (TrypLE.RTM.) and mechanically
dissociated to yield a single cell suspension. The solution was
centrifuged at 169 g for 6 minutes and the pellet was resuspended
in Dulbecco's Modified Eagle Medium (DMEM). Cells were plated in a
25 .mu.L micro-island at a density of 4000 cells/.mu.L on
poly-D-lysine coated 24-well plates (Sigma). Following adherence,
cells were supplemented with warm NEUROBASAL.TM. media containing 2
mM glutamine, 1.times.N.sub.2, and 100 units of
penicillin/streptomycin. Neurotrophic compounds were added at each
media addition, including initial plating and DIV 2. A dose
response of the peptides (0.03 ng to 10 ng/mL) was added to a
24-well plate following media supplementation.
[0123] MN9D Cell Cultures: The MN9D cell line has been described by
Choi (1991) Brain Res. 552:67-76 and was a gift from Michael
Zigmond. Cells were cultured in DMEM supplemented with 10% Fetal
Bovine Serum (FBS, Hyclone), 50 U/mL penicillin and streptomycin.
For experiments, the cells were plated on 24-well poly-D-lysine in
DMEM with 1% (v/v) penicillin-streptomycin. The cells were grown at
37.degree. C. in 5% CO.sub.2.
[0124] Caspase-3 Activity Assay in MN9D Cells: MN9D cells were
plated to 100,000 cells/well. Cell cultures were exposed to DNSP-11
(1 ng/mL) or buffer for 1 hour prior to 15 min 100 .mu.M 6-OHDA
exposure. Caspase-3 activity was monitored after 3 hours by
fluorescence (excitation/emission 496/520 nm) using the Enz Chek
Caspase-3 kit. Protein levels of lysed cells were measured by BCA
assay (BioRad) and normalized for every experiment. Data expressed
as % control and repeated a minimum of 3 times.
[0125] Terminal dUTP Nick-End Labeling (TUNEL) Assay in MN9D Cells:
After treatment with DNSP-11, MN9D cells were fixed and labelled to
assess degenerative nuclear changes as indicated by the extent of
high-molecular weight DNA strand breaks. DNA fragmentation was
detected by using steptavidin-horseradish peroxidise conjugate
followed by the substrate diaminobenzidine (DAB) generating a
colored precipitate. Ratios between apoptotic and total cells were
determined (4 random fields/well; 4 wells/group). Experiments were
repeated 3 times.
[0126] Double Fluorescent Immunostaining of DNSP-11: Floating
sections were pretreated with 0.2% H.sub.2O.sub.2 in potassium
phosphate buffered saline (KPBS) for 10 minutes and blocked with 4%
normal goat serum in KPBS for 1 hour. Then, sections were incubated
overnight with both rabbit anti-hDNSP-11 antibody (1:2000, Alpha
Diagnostic) and mouse anti-TH antibody (1:1000, Chemicon) in KPBS
at 4.degree. C. After washing with KPBS, the sections were
incubated with Alexa-488 conjugated goat anti-rabbit IgG (1:500,
Molecular Probes) and Alexa-568 conjugated goat anti-mouse IgG
(1:500, Molecular Probes) for 3 hours. The sections were washed
extensively and visualized with a Nikon fluorescence
microscope.
[0127] Animals and Surgical Procedures for Normal and
6-OHDA-Lesioned Rats: Fischer 344 (F344) rats were used for all
experiments and maintained under a 12 hour light/dark cycle with
food and water provided ad libitum. All procedures were approved by
the University of Kentucky Institutional Animal Care and Use
Committee following AAALACI guidelines.
[0128] Infusion Delivery of DNSP-11 or Vehicle: Isoflurane
anesthetized (1.5-2.5%) F344 rats received 5 .mu.l of 6 .mu.g/.mu.L
DNSP-11 solution or citrate buffer vehicle solution in a blinded
manner. Treatment was delivered to the nigral cell bodies using the
same stereotaxic coordinates and protocol for solution delivery as
in studies of GDNF.
[0129] Reverse Microdialysis: Reverse in vivo microdialysis was
accomplished using methods and brain coordinates described by
Hebert et al. (1996) J. Pharmacol. Exper. Ther. 279:1181-1190. CMA
11 microdialysis probes with a 4.0 mm membrane length and 6 kDa
molecular weight cut-off were placed within the rat striatum.
[0130] Unilateral 6-OHDA Lesions: The 6-OHDA solution was delivered
to two injection sites along the medial forebrain bundle (MFB)
using a protocol described by Lundblad et al. (2002) Eur. J.
Neurosci. 15:120-132. Five weeks after the unilateral 6-OHDA MFB
lesion procedure, animals were grouped based on apomorphine (0.05
mg/kg, s.c.)-induced rotational behaviour: Animals with >300
rotations per 60 minutes were selected. Lesioned animals received 5
.mu.L of either a 20 .mu.g/.mu.L DNSP-11 solution or citrate buffer
vehicle solution in a manner similar to infusion delivery in normal
animals.
[0131] Neurochemical Content of Tissue: Lesioned animals were
euthanized 5 weeks after DNSP-11 or vehicle infusion. The brains
were sliced into 1 mm thick sections. Tissue punches were taken
from the striatum and the substantia nigra and they were weighed,
quick frozen and stored at -70.degree. C. until they were assayed
by high performance liquid chromatography with electrochemical
detection as described by Hall et al. (1989) LC/GC-Mag Sep Sci
7:258-265.
[0132] Apomorphine-induced Rotational Behavior Testing: Lesion
severity was assessed prior to DNSP-11 treatment using apomorphine
(0.05 mg/kg, s.c.)-induced rotational behavior. Beginning one week
after DNSP-11 treatment, apomorphine-induced rotational behavior
was monitored weekly for four weeks as described by Hoffer et al.
(1994) Neurosci Lett. 182:107-111 (1994) and Hudson et al. (1993)
Brain Res. 626:167-174 (1993).
[0133] DNSP-11 Pull-down analysis: The F344 substantia nigra was
homogenized in homogenization buffer (modified from York et al.
(2005) FASED J. 19: 1202-4 with 20 mM HEPES, pH 7.4) and cytosolic
fraction (supernatant) collected after 30 minutes at 100,000 g. 50
.mu.g of bDNSP-11 was incubated with fraction for 15 minutes on
ice. Sample was added to streptavidin magnetic beads (New England
Biolabs), pelleted, and washed four times in homogenization buffer.
Bound proteins were eluted by Solubilization/Rehydration Solution
(7M Urea, 2M Thiourea, 50 mM DTT, 4% CHAPS, 1% NP-40, 0.2% Carrier
ampholytes, 0.0002% Bromophenol blue), and analyzed by 2D-PAGE and
MALDI-TOF MS.
Example 6: Neurobiological Actions of DNSP-11
[0134] GDNF is endogenously produced as a pre-proprotein of 211
amino acids that is processed and secreted as a mature homodimer
with a molecular weight of 32-42 kDa. The following examples
illustrate the neurobiological actions of dopamine neuron
stimulating peptide-11 (DNSP-11), an 11-mer peptide that has been
independently predicted to be an endopeptidase cleavage product
from the human GDNF prosequence (FIG. 10A).
[0135] FIGS. 10A and 10B illustrate the sequence origin and
homology of DNSP-11. DNSP-11 (filled) is an 11 amino acid sequence
present in the proprotein region of the 211 amino acid human
preproGDNF sequence. After cleavage of the pre-signal sequence
(shaded), DNSP-11 is predicted to be cleaved from the proprotein at
flanking dibasic cleavage sites by endopeptidases. Further
predicted processing yields the C-terminal amidated peptide. The
N-terminal (striped) and C-terminal (checkered) proprotein
fragments and mature GDNF (open) protein are shown. The sequence
figure is not drawn to scale to highlight the processing of
DNSP-11. DNSP-11 (FIG. 10B) shows high sequence homology to the rat
and mouse proGDNF sequences suggesting a conserved function.
[0136] In vivo expression of the DNSP-11 sequence in the substanta
nigra of the ventral mesencephalon from SD pups at postnatal day 10
(PN10) was examined. Immunostaining for DNSP-11 in the
mesencephalon of the SD pups indicated that the sequence is present
endogenously in tyrosine hydroxylase positive (TH+) dopaminergic
neurons of the substantia nigra at PN10 ns (yellow). The DNSP-11
sequence colocalized within dopaminergic cell bodies at PN10.
[0137] The neurotrophic effects of DNSP-11 were studied by
comparing its effects to the well-known effects of GDNF on the
maintenance of primary mesencephalic cell cultures from E14 SD rat
embryos. E14 SD rat embryo primary dopaminergic neurons from the
ventral mesencephalon were grown for 5 days in vitro and
neurotrophic molecules were added at each media change, including
initial plating and day 2. GDNF (FIG. 11A, open bars) and DNSP-11
(FIG. 11A, solid bars) were added at various concentrations (0.03,
0.1, 1.0 and 10 ng/ml; 10 mM citrate buffer+150 mM NaCl, pH 5) and
were seen to significantly increase TH+ neuron counts (+SD; one-way
ANOVA with Newman-Keuls post hoc analysis, *p<0.05 and **
p<0.01) Specifically, DNSP-11 increased cell survival 75% over
citrate buffer control, as indicated by immunocytochemical staining
of TH+ neurons 5 days in vitro (FIG. 11A). Furthermore, DNSP-11
significantly enhanced morphological changes consistent with a
neurotrophic molecule including: neurite length, total number of
branches, and increased total number of TH+ cells (Table 4; FIG.
11B). These effects were similar to those observed for GDNF in
these cells, including an increase in the size of TH+ neurons,
which was not observed for DNSP-11 (Table 4). Photographs in FIG.
11B of treated E14 primary dopaminergic neurons demonstrate that
both GDNF and DNSP-11 treated cells (0.1 ng/ml) displayed enhanced
cell survival, neurite length, and total number of branches.
[0138] In Table 1, cell survival and morphological parameters were
quantified for control (citrate buffer) and experimental (0.1 ng/ml
GDNF or 0.1 ng/ml DNSP-11) conditions. For morphology, five fields
per well (minimum of 15 cells/field; 3-4 independent experiments)
were photographed at 20.times. magnification and quantified using a
Bioquant Image Analysis System. DNSP-11 increased cell survival and
morphological parameters comparable to GDNF, including combined
neurite length and total branches. Soma size was not increased by
the addition of DNSP-11. A one-way ANOVA was used to test for
significance among groups, followed by a Newman-Keuls post hoc
analysis. Significance between control and experimental conditions
was determined at *p<0.05 and **p<0.01.
TABLE-US-00004 TABLE 4 GDNF DNSP-11 Control 0.1 ng/ml Control 0.1
ng/ml Cell survival 100 .+-. 15 *158 .+-. 12 100 .+-. 16 *161 .+-.
17 n = 8 n = 8 n = 7 n = 7 Combined neurite 242 .+-. 12 **310 .+-.
16 222 .+-. 11 **306 .+-. 23 length (um) n = 135 n = 106 n = 139 n
= 59 Soma size (um.sup.2) 171 .+-. 4 177 .+-. 4 168 .+-. 3 165 .+-.
5 n = 135 n = 106 n = 139 n = 59 Average branches 3.8 .+-. 0.2
**4.7 .+-. 0.2 3.1 .+-. 0.2 **4.4 .+-. 0.3 per neuron n = 135 n =
106 n = 139 n = 59
[0139] To evaluate DNSP-11's neuroprotective properties, DNSP-11
was compared to GDNF in its protection against 6-OHDA-induced
toxicity in the dopaminergic cell line, MN9D. MN9D dopaminergic
cells were incubated for 1 hour with either citrate buffer
(control), 1 ng/mL of DNSP-11 or GDNF prior to 100 .mu.M 6-OHDA
exposure for 15 min. Data are +SD, one-way ANOVA with Tukey's post
hoc analysis, *p<0.05, **p<0.01, ***p<0.001 vs. control;
#p<0.05, ##p<0.01, ###p<0.001 vs. 6-OHDA. As seen in FIGS.
11C and D, 100 .mu.M 6-OHDA significantly increased TUNEL staining
and caspase-3 activity in MN9D cells (FIGS. 11C and D).
Pretreatment with DNSP-11 or GDNF produced a significant reduction
in the percent of TUNEL positive cells and caspase-3 activity
(FIGS. 11C and D). Thus both DNSP-11 and GDNF protect against
6-OHDA toxicity as demonstrated by reductions in TUNEL staining at
24 h (FIG. 11C) and caspase-3 (FIG. 11D) activity at 3 h after
6-OHDA exposure.
Example 7: Uptake of DNSP-11 into Neurons
[0140] Additional studies were carried out to determine if DNSP-11
is actively taken up into dopamine-containing neurons in vivo. A
single administration of 30 .mu.g of DNSP-11 was delivered into the
rat substantia nigra. Animals were euthanized at 0.5, 1.5, 4, 24
and 48 hrs after injection to visualize distribution of DNSP-11
using antibodies raised against DNSP-11 and the ubiquitinated form
of DNSP-11. DNSP-11 antibodies labelled the cytosol and neurites of
neurons in the area of the substantia nigra within 30 minutes after
injection. DNSP-11 was taken up by neurons in both the substantia
nigra, pars reticulata (SNr) and substantia nigra, pars compacta
(SNc). The fluorescent immunostaining for DNSP-11, TH and the
merger of photomicrographs from each showed that TH-positive
dopamine neurons populate the SNc and the ventral tegmental area
(VTA). Higher power micrographs from the SNc. DNSP-11
immunostaining revealed uptake into the perikaryon, nucleus, and
neurites of TH+ cells.
[0141] At 1.5 hrs post-injection, staining for TH+ and DNSP-11
showed overlap in the pars compacta of the substantia nigra and
some labeling in the pars reticulata, supporting potential uptake
of DNSP-11 into GABAergic neurons. Immunohistochemical staining for
DNSP-11 diminished 3 hrs after injection and was absent at 24 hrs
and beyond, indicating that there is a rapid uptake of DNSP-11 into
neurons.
[0142] B65 dopaminergic cells were incubated with FITC-DNSP-11 and
Confocal microscopy images were used to follow the internalization
of DNSP-11-FITC-DNSP-11 (10 nM, green) into the cells.
Immunofluorescence staining 3 hours after treatment showed that
FITC-DNSP-11 was within the plasma membrane and is colocalized into
the lysosomes. Mitochondrial staining showed that there is limited
FITC-DNSP-11 colocalization at 3 hours (data not shown).
Example 8: Effect of DNSP-11 on Dopamine Neurochemistry
[0143] Prior studies with GDNF have shown robust effects on both
potassium and amphetamine-evoked release 28 days after a single
injection into the rat substantia nigra (Hebert et al. (1997) J
Pharm. Exp. Thera. 282: 760) indicating the functional effects of
this trophic factor on dopamine signaling in the normal rat
striatum. In the present experiment, 30 .mu.g of DNSP-11 was
injected into the right substantia nigra of normal young male
Fischer 344 rats. Twenty-eight days after injection, in vivo
microdialysis was performed in these animals to investigate
dopamine neurochemistry in the ipsilateral striatum. Resting levels
of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and
homovanillic acid (HVA) were significantly increased by over 100%
in the DNSP-11 treated rats as compared to controls (FIG. 12A).
These data indicate longer term effects of DNSP-11 on dopamine
neuron function, and are analogous to prior results involving GDNF
administration in rats and nonhuman primates. Winkler et al. (1996)
J Neurosci. 16: 7206; Hebert et al. (1996) J Pharmacol Exper Ther.
279: 1181-1190 (1996).
[0144] The in vitro studies and in vivo measures of the effects of
DNSP-11 led to an investigation of the potential neurorestorative
properties of DNSP-11 to damaged dopamine neurons in a unilateral
rat model of PD. Fischer 344 rats received dual-site unilateral
injections of 6-OHDA to produce extensive destruction of the
ascending dopaminergic system that resulted in a greater than 99%
depletion of striatal dopamine content ipsilateral to the site of
the 6-OHDA injections. Rats were tested 3-4 weeks after the
injection of 6-OHDA using low-dose (0.05 mg/kg, i.p.)
apomorphine-induced rotational behavior. In rats that rotated
greater than 300 turns/60 minutes, 30 .mu.g of DNSP-11 was injected
into the ipsilateral substantia nigra. DNSP-11 produced a
significant .about.50% decrease in apomorphine-induced rotational
behavior that was significant 1 week after administration and this
effect was maintained for at least 4 weeks after DNSP-11 (FIG.
12B). At 5 weeks, the substantia nigra and striatum from each rat
was analyzed by high performance liquid chromatography coupled with
electrochemical detection. A single injection of DNSP-11 was found
to significantly increase levels of dopamine and the dopamine
metabolite, DOPAC, by .about.100% in the substantia nigra,
indicating that DNSP-11 has a powerful neurotrophic-like
restorative effect on dopamine neurons in this animal model of late
stage PD (FIG. 12C).
[0145] As shown in FIG. 12A, 28 days after DNSP-11 or citrate
buffer vehicle was delivered to the nigral cell bodies, the DNSP-11
treatment group showed significantly higher basal neurochemical
concentrations of DA, DOPAC and HVA. Basal DA increased from
26.0.+-.2.7 nM in the vehicle treatment group to 45.8.+-.7.7 nM in
the DNSP-11 treatment group (t.sub.(31)=2.255, p=0.0314). Basal
concentrations of DOPAC increased from 3355.+-.338 nM in the
vehicle group to 6544.+-.836 nM in the DNSP-11 group
(t.sub.(31)=3.293, p=0.0025), and HVA, increased from 2419.+-.251
nM with vehicle treatment to 4516.+-.502 nM with DNSP-11 treatment
(t.sub.(30)=3.588, p=0.0012). All data were analyzed using a
two-tailed unpaired t-test * p<0.05. FIG. 12B shows the results
of assessment of apomorphine (0.05 mg/kg) induced rotational
behavior prior to infusion treatment (Pre) and once weekly for 4
weeks after DNSP-11 or vehicle treatment. Drug-induced rotational
behavior is expressed as a percentage of vehicle treatment and
showed a significant decrease in rotational behavior beginning one
week after DNSP-11 treatment that lasted for all 4 weeks post
DNSP-11. The data were analyzed using a one-way ANOVA for repeated
measures (F.sub.(4,39)=4.807, p=0.0005) with Bonferroni's multiple
comparison test * p<0.05, ** p<0.01, *** p<0.001. FIG. 12C
shows that DNSP-11 treatment significantly increased levels of DA,
(74%) and DOPAC (132%) in the substantia nigra of unilateral
6-OHDA-lesioned rats. DA content was determined to be 34.7.+-.6.4
ng/g in the vehicle treatment group and 59.1.+-.7.3 ng/g in the
DNSP-11 treatment group (t.sub.(13)=2.521, p=0.0265). DOPAC tissue
content was determined to be 7.10.+-.1.40 ng/g in the vehicle
treatment group and 16.48.+-.4.01 ng/g (t.sub.(13)=2.33, p=0.0364)
in the DNSP-11 treatment group. All data were analyzed using a
two-tailed unpaired t-test, * p<0.05.
Example 9: Interaction of DNSP-11 with Protein Partners
[0146] In order to identify the interactions of DNSP-11 with
protein partners and to gain insight into the cellular mechanisms
involved with the actions of DNSP-11, a pull-down assay was
performed with homogenate from isolated substantia nigra of normal
young Fischer 344 rats. Cytosolic and membrane fractions were
collected and incubated with biotinylated DNSP-11 for 30 minutes.
Bound proteins were pulled down by strepavidin magnetic beads,
extensively washed to remove non-specific binders, eluted with
solubilization/rehydration buffer and separated by 2D-PAGE.
[0147] Specifically, a solution of 25 .mu.L GFR.alpha.1 (1 mg/mL)
was incubated with 50 .mu.L of Dynabeads.RTM. (Invitrogen) in wash
and bind buffer (0.1M sodium phosphate, pH 8.2, 0.01% Tween.RTM.
20) for 10 minutes at room temperature. The beads were then washed
three times in 100 .mu.L of wash and bind buffer. 2 .mu.g of GDNF
was added and incubated for 1 hour at 4.degree. C. 25 .mu.L
GFR.alpha.1 (1 mg/mL) was incubated with 40 .mu.g of biotinylated
DNSP-11 (bDNSP-11) for 1 hour at 4.degree. C. They were then added
to 50 .mu.L of hydrophilic streptavidin magnetic beads (New England
Biolabs) and incubated for an hour at 4.degree. C.
[0148] Several spots were observed in both the cytosolic and
membrane fractions, indicating that DNSP-11 is able to bind
proteins found within the substantia nigra. To identify these
binding partners, protein bands were excised from the gels, trypsin
digested, and analyzed by MALDI-TOF mass spectrometry. From these
preliminary studies, approximately 20 proteins were identified. Of
these, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a protein
with a link to PD and apoptosis, was identified. This result was
confirmed by in vitro pull down assays with pure GAPDH and
DNSP-11.
[0149] In addition, a pull-down assay of DNSP-11 with GFR.alpha.1
indicated that the two molecules do not interact, like mature GDNF
(FIG. 13; F-Flow through, E-Elution). Moreover, the absence of
interaction between GFR.alpha.1 with DNSP-11 is supported by
ELISA.
[0150] A gel filtration study was performed using a 120 mL
Sephacryl S-200 column at a constant 1 mL/min flow rate. Individual
300 .mu.M solutions of GAPDH (.about.150 kDa; FIG. 14, dotted line)
or GDNF (.about.30 kDa; FIG. 14, dashed line) eluted at expected
retention times for their sizes of 50 min (FIG. 14, star) and 64
min (FIG. 14, pound sign), respectively. When a pre-equilibrated (1
h), equimolar solution of GAPDH and GDNF was analyzed by gel
filtration chromatography, two equally intense peaks were observed
(FIG. 14, solid line) with retention times identical to the
individual solutions. These data demonstrate that GDNF does not
interact with GAPDH in solution, thereby providing evidence that
DNSP-11 has an independent mechanism of action relative to mature
GDNF.
[0151] Taken together, these data indicate that DNSP-11 exhibits
potent neurotrophic actions analogous to GDNF, but likely signals
through pathways that do not directly involve the GFR.alpha.1
receptor.
[0152] The foregoing examples demonstrate that DNSP-11 shares many
physiological and neurotrophic properties with mature GDNF,
including neuroprotection and promoting differentiation in primary
dopamine neuron cell cultures; increasing dopamine release and
metabolism in vivo; and decreasing apomorphine-induced rotations
and enhancing dopamine function in the substantia nigra of 6-OHDA
lesioned rats.
Example 10: DNSP-11 Solubility and Stability
[0153] The backbone secondary structure of DNSP-11 was examined
using circular dichroism spectroscopy in the far-UV region (CD;
University of Kentucky Center of Structural Biology). The DNSP-11
spectrum (FIG. 15A) displayed a broad minimum mean residue
ellipticity (MRE) at 200 nm, indicative of a peptide that it is
dynamic and samples multiple confirmations. Small shoulders between
208-230 nm indicate that DNSP-11 appears to be sampling polyproline
II and other helical structures. Collectively, the spectrum of
DNSP-11 shows that it has characteristics of typical small,
soluble, functional peptides of similar length.
[0154] Reverse Phase HPLC (RP-HPLC; FIG. 15B); University of
Kentucky Center of Structural Biology) and electrospray mass
spectrometry (University of Kentucky Mass Spectrometry Facility)
were used to monitor at the stability of DNSP-11. DNSP-11 was
stored in citrate buffer (10 mM Citrate+150 mM NaCl, pH 5.0) at
-80.degree. C. and 37.degree. C. for 30 days. These temperatures
were chosen based on their relevance to long term storage and use
in future studies. The results of these studies showed that the
peptides were stable at both temperatures for one month without any
appreciable loss of peptide (FIG. 15C).
[0155] Our analysis of the effects of DNSP-11 on dopamine neurons
in the nigrostriatal system of the brain of young adult F344 rats
at 28 days following a single injection of the peptide,
demonstrated a surprising effect, i.e., an increase in basal tissue
levels of the dopamine metabolite 3,4-dihydroxyphenylacetic acid
(DOPAC, see FIG. 16). The 100% increase in DOPAC was unprecedented
in our numerous experiments over the past 20 years. In fact, we
have never seen a dopamine-altering agent, which increases the
metabolism of dopamine by 100% and this effect was seen to persist
for one month after a single injection of DNSP-11 into the
substantia nigra, which is the source of the dopamine-containing
fibers measured in the striatum. GDNF, which augmented the evoked
release of dopamine by over 100%, increased basal levels of DOPAC
by only 20-25% in young and aged rats (Herbert et al. J Pharmacol.
Exp. Therapeut. (1996) 279:1181-1190, and Hebert and Gerhardt, J
Pharmacol. Exp. Therapeut. (1997) 282:760-768). Based on the
results presented herein, and the knowledge that DOPAC is produced
when dopamine is metabolized by monoamine oxidase B, (an enzyme on
the outer membrane of mitochondria (Edmondson et al, Curr. Med Chem
(2004) 11(15:1983-93) and then the product of this reaction is
metabolized by aldehyde dehydrogenase (which resides in the cytosol
of cells) we reasoned that DNSP-11 increases mitochondrial
functions and thereby increases monoamine oxidase levels. The
following examples address this.
Example 11: DNSP-11: Distribution, Uptake and Half-Life in the
Brain
[0156] To assess the distribution, uptake and degradation of
DNSP-11 in the brain, young adult male F344 rats, as a test
organism, received injections of 30 .mu.g DNSP-11 in the substantia
nigra, hippocampus or cortex. They were euthanized by anesthesia
overdose at various time points from 30 minutes to 48 hrs later and
perfused through the heart with saline followed by
paraformaldehyde.
[0157] Our standard published procedures for immuncytochemical
staining were used (e.g. Gash D M et al., J Comp Neurol. 1995 Dec.
18; 363(3):345-58., Grondin et al., 2002; Ai et al., 2003). A
polyclonal antibody was generated against DNSP-11 in rabbits (Alpha
Diagnostic International, San Antonio, Tex.). Endogenous
peroxidases were inactivated by incubation with 0.2% hydrogen
peroxide (H.sub.20.sub.2) for 10 minutes and background blocked
with 4% normal serum, 1% bovine serum albumin (BSA) for 1 hour.
Free floating sections were incubated in primary antisera. Sections
were then exposed to the appropriate biotinylated IgG (Vecto Labs,
Burlingame, Calif.) for 1 hour and then incubated in
avidin-biotin-peroxidase complex using Elite ABC Vectastain Kits
(Vector Labs) for 1 hour. Some sections were double-labeled using
procedures following our published procedures for
immunocytochemical staining to identify cells with two markers
(e.g. Ai et al., 2003).
[0158] Controls for immunostaining included the omission of primary
antibodies and replacement of primary antibodies with normal serum
of the same species.
[0159] Results: A 30 .mu.g bolus of DNSP-11 injected into the
mid-substantia nigra region using stereotaxic procedures spreads
.about.3 mm in the anterior-posterior plane and up to .about.2 mm
in the medial-lateral plane (FIG. 17) to cover most of the pars
compacta component of the nigra. DNSP-11 is taken up in the first
30 minutes following injection by neurons and their axonal and
dendritic processes. It is found in the cytoplasm and then
perinuclear area and nucleus. At 24 hours after injection, some
residual DNSP-11 can still be detected. There was no evidence of
DNSP-11 by 48 hours post peptide administration.
[0160] Stereotaxic injections of 30 .mu.g DNSP-11 were also made
into the striatum, hippocampus and cortex. Uptake was observed into
neurons in both areas. Pyramidal neurons in the cortex accumulated
DNSP-11.
[0161] In summary, DNSP-11 is taken up within 30 minutes by neurons
in all brain areas evaluated. The uptake sites appear to be
specific for axons, dendrites, synaptic terminals and perikarya of
nerve cells. DNSP-11 immunostaining is found in the cytoplasm and
then in the nucleus. The half-life of DNSP-11 in the rat brain is
under 24 hours. The areas of the brain studied (substantia nigra,
striatum, hippocampus and cortex) have major roles in cognitive and
motor functions. Tropic actions of DNSP-11 could protect these
brain areas from injury and/or promote restoration from disease and
injury processes.
Example 12: DNSP-11 Induced Changes in Genes Regulating
Mitochondria/Functions
[0162] Changes in expression of mitochondrial-associated genes in
the substantia nigra (SN) of three young adult (5 month old) male
F344 rats 48 hours following bilateral intranigral injections of
DNSP-11 into the substantial nigra was assessed as follows.
[0163] A 3 .mu.g/.mu.l DNSP-11 peptide solution was prepared in
citrate buffer and filter sterilized. Stereotaxic injections were
made of 30 .mu.g DNSP-11 in 10 ul citrate buffer into the
substantia nigra on each side of the brain. Controls received 10
.mu.g injections of vehicle. Forty-eight hours later, the animals
were euthanized, the brains quickly recovered and sectioned so that
the bilateral SN could be dissected out as one block of tissue and
snap frozen in liquid nitrogen. RNA was extracted from the SN
samples for gene array analysis, which was conducted on Affymetrix
Version II chips. A gene chip was run for each of the six rats:
three bilateral vehicle recipients, three bilateral 30 .mu.g
DNSP-11 recipients.
[0164] Genes regulating mitochondrial functions were identified as
the subset of genes on the microarray in the peptide-treated group
having expression levels that were significantly increased or
decreased as compared to the controls (Table 5). Fourteen genes
were significantly up-regulated and five were significantly
down-regulated in DNSP-11 recipients. One gene with increased
expression was Monoamine Oxidase B, a finding consistent with the
higher DOPAC levels mentioned earlier. A number of other genes with
increased expression are associated with protection against
oxidative damage: glutathione/glutaredoxin, glutathione peroxidase
and thioredoxin (Koehler et al., Antioxid Redox. Signal.,
8(5-6):813-22 (2006); Comhair & Erzurum Antioxid Redox Signal.,
7(1-2):72-9. (2005)). Catalase is an important enzyme converting
the strong oxidant hydrogen peroxide to water- and oxygen (Calderon
I L et al., PLoS ONE. 1:e70 (2006 Dec. 20)). Peroxyredoxin is
another antioxidant (Rhee, Chae & Kim, Free Radic Biol Med.
2005 Jun. 15; 38(12):1543-52. Epub (2005 Mar. 24)). Increased
levels of Park 7 (DJ-1) are protective against Parkinson's disease
(Thomas & Beal, Hum Mol Genet. 16 Spec No. 2:R183-94 (2007 Oct.
15)) and increase levels of Presenilin 1 are believed to be
protective against Alzheimer's disease (Das, Front Biosci.
13:822-32 9 (2008 Jan. 1)). In both instances, it is a decreased or
mutant form of the gene that is closely linked to neurodegenerative
diseases. The cytochrome c oxidase subunits are components of the
terminal respiratory complex producing energy via oxidative
phosphorylation.
[0165] The caspases having increased expression are associated with
apotosis (Kataoka, Crit Rev Immunol. 25(1):31-58 (2005); Vassar,
Neuron 54(5):671-3 (2007)). Without wishing to be bound by theory,
the increased expression of low levels capases may reflect a
nonspecific inflammatory reaction to the mild physical injury
induced by the needle track and injection of material into the
substantia nigra.
TABLE-US-00005 TABLE 5 Changes in expression level post DNSP-11
delivery FOLD SYMBOL DESCRIPTION PEPTIDE CONTROL P-VALUE CHANGE
GLRX2 glutaredoxin 2 3618.7 3472.2 <0.001 1.09 CASP8 caspase 8,
apoptosis-related cysteine 219.4 178.1 0.006 1.25 peptidase TXN2
thioredoxin 2 1511.9 1378.5 0.010 1.10 MAOB monoamine oxidase B
2199.8 1974.2 0.012 1.13 COX6A2 cytochrome c oxidase subunit Via
814.1 520.6 0.014 1.75 polypeptide2 GPX7 glutathione peroxidase 7
194.2 183.8 0.015 1.19 CAT catalase 2828.2 271a.0 0.015 1.09 PRDX5
peroxiredoxin 5 5569.8 4790.1 0.020 1.13 PSEN1 presenilin 1
(Alzheimer disease 3) 673.5 563.2 0.022 1.16 CASP3 caspase 3,
apoptosis-related cysteine 421.4 367.5 0.024 1.18 peptidase COX17
COX17 cytochrome c oxidase assembly 2326.1 2017.8 0.025 1.11
homolog (S. cerevisiae) PARK7 DJ-1 protective against Parkinson's
disease 5299.2 5159.4 0.032 1.02 COX6B1 cytochrome c oxidase
subunit Vib 7869.7 7536.6 0.044 1.04 polypeptide 1 (ubiquitous)
NDUFA7 NADH dehydrogenase (ubiquinone) 1 3125.4 2943.0 0.046 1.07
alpha subcomplex, 7, 14.5 kDa APP amyloid beta (A4) precursor
protein 9734.4 10117.2 0.006 -1.08 (peptidase nexin-II, Alzheimer
disease) MAPK9 mitogen-activated protein kinase 9 770.7 930.0 0.007
-1.21 MAPK10 mitogen-activated protein kinase 10 505.0 552.8 0.008
-1.08 BACEI beta-site APP-cleaving enzyme 1 451.6 510.6 0.016 -1.09
MAP2K4 mitogen-activated protein kinase kinase 4 2422.4 2744.4
0.043 -1.12
The foregoing results indicate that DNSP-11 treatment significantly
effects the expression of genes regulating mitochondrial functions.
The changes in gene expression would be neuroprotective against
free radical oxidative damage to mitochondria. This would decrease
mitochondrial wear and tear from oxidative respiratory processes
producing energy, increasing the functional lifespan of
mitochondria in a neurons and synapses.
Example 13: DNSP-11 Increases State III Mitochondria/Respiration in
the Rat Nigrostriatal System
[0166] As our previous studies had demonstrated that injections of
30 .mu.g DNSP-11 into the substantia nigra had marked effects 28
days post administration with elevated levels of dopamine and
dopamine metabolites in the nigrostriatal system (substantia nigra
and its projections to the striatum), we quantified the effects of
DNSP-11 on mitochondria respiration and enzyme activity in the
nigrostriatal system of young adult F344 rats at 28 days post
injection.
[0167] Six five-month-old male F344 rats received bilateral
intranigral injections of 30 .mu.g DNSP-11. Six age and sex-matched
controls received injections of the same volume of vehicle (citrate
buffer). Twenty-eight days after test material administration, the
animals were euthanized by CO.sub.2 anesthesia and the brain
samples rapidly dissected. The striatum and substantia nigra were
isolated quickly and carefully using a rat brain matrix for F344
rats.
[0168] Mitochondrial respiration was assessed using a miniature
Clark-type electrode, in a sealed, thermostatic and continuously
stirred chamber. Mitochondria were added to the chamber to yield a
final protein concentration of 1 mg/ml. The substrate
concentrations were 5.0 mM/2.5 mM for glutamate/malate and
pyruvate/malate or 10 mM for succinate+2.5 .mu.M rotenone or
.alpha.-glycerophosphate. State 3 respiration was initiated by the
addition of 150 .eta.mols ADP. The respiratory control ratio was
calculated as respiration in the presence of ADP (state
3)/respiration in absence of ADP (state 4). ADP/0 ratios were
determined by dividing the amount of ADP phosphorylated during
State Ill respiration by the amount of oxygen consumed. NAD-linked
substrates, e.g. glutamate and pyruvate, utilize complexes I, Ill,
IV in their oxidation, succinate utilizes complexes II, Ill, IV and
.alpha.-glycerophosphate ultilizes III, IV. Thus impaired oxidation
of NAD-linked substrates, but normal oxidation of succinate or
.alpha.-glycerophosphate implies a defect at the level of complex
I. Impaired oxidation of both NAD-linked and succinate oxidation
implies a defect in both complex I and II and/or in complex III and
IV which can be elucidated by the use of
.alpha.-glycerophosphate.
[0169] The chamber was also equipped with fluorescence/absorbance
probes which allow us to also measure simultaneously ROS production
in real-time with all other parameters. ROS production was measured
using the H.sub.2O.sub.2 indicator dichlorodihydrofluorescein
diacetate (H.sub.2DCFDA, Molecular Probes). Ten .mu.M H.sub.2DCFDA,
which is made fresh before each use, was added to the chamber and
the relative amount of mitochondria) H.sub.2O.sub.2 and free
radical production measured as an increase in fluorescence. Again
the same rationale as above can be used to pinpoint the source of
ROS production. Additionally, ROS production was monitored over
time in a Synergy HT plate reader or a Shimadzu RF-5301
spectrofluorimetre with stirred and water-jacketed cuvett holders
(excitation 490 .eta.m, emissions 526 .eta.m; ex550 .eta.m, em590
.eta.m, respectively) at 37.degree. C. for 15 min in the presence
of 10 .mu.M H.sub.2DCFDA or Amplex Red, a H.sub.2O.sub.2 indicator
that is extramitochondrial. Controls include the addition of the
electron transport chain inhibitor antimycin (complex III
inhibitor, yields maximum ROS production independent of
.DELTA..PSI.), oligomycin (inhibits ATPase yielding maximum
.DELTA..PSI.-dependent ROS production) and the uncoupler FCCP
(inhibits all .DELTA..PSI.-dependent ROS production).
[0170] The mitochondria were freeze-thawed and sonicated three
times for measuring all the complexes activities. Complex I (NADH
dehydrogenase) assay is performed in 2.5 mM KPO.sub.4 buffer (pH
7.2) containing mitochondrial protein (6 .mu.g), 5 mM MgCl.sub.2, 1
mM KCN, 1 mg/ml BSA, and 150 .mu.M NADH at 30.degree. C., the
reaction initiated by addition of coenzyme Q-1 (50 .mu.M). In this
reaction ubiquinone 1 was the final electron accepter. The decrease
in NADH absorbance at 340 .eta.m was monitored. The assay was also
performed in the presence of rotenone (10 .mu.M) to determine the
rotenone-insensitive and the rotenone-sensitive complex I enzyme
activity. Complex II (succinate dehydrogenase) activity was
measured by the rate of reduction of 2,6-Dichloroindophenol. The
reaction mixture contained 100 mM KPO.sub.4 buffer, 20 mM
succinate, 10 .mu.M EDTA, 0.01% Triton, 1 .mu.g/100 .mu.l coenzyme
Q2 containing mitochondria) protein (6 .mu.g) at 30.degree. C. and
the reaction was initiated by the addition of 0.07%
2,6-Dichloroindophenol. Decreased in absorbance was monitored at
600 .eta.m. Complex IV (cytochrome c oxidase) activity was measured
in 10 mM KPO.sub.4 buffer and 50 .mu.M reduced cytochrome c. The
reaction was initiated by addition of 6 .mu.g mitochondria)
protein. Rate of oxidation of cytochrome c was measured by
measuring the decrease in absorbance of reduced cytochrome c,
observed at 550 nm.
[0171] As shown in FIG. 18, there was a trend towards an increase
in State III oxidative phosphorylation at 28 days post treatment in
the substantia nigra. However, with an n=2, the difference was not
significant with a two-tailed t-test. The effects reached
statistical significance in the striatum, which is heavily
innervated by dopamine fibers from the substantia nigra forming
synapses on striatial medium spiny neurons. Evidence described in
Example 12 indicates that DNSP-11 was taken up within 30 minutes
into neuritic processes and cell bodies of neurons. Soon
thereafter, immunoreactive DNSP-11 was found in the nucleus. The
effects at 28 days on dopamine and metabolite levels and on
mitochondria demonstrate that DNSP-11 treatment initiates genetic
changes that last for long periods, at least one month, and without
wishing to be bound by theory, this may occur perhaps through
receptors involving transcribing factors.
[0172] Within 30 minutes following a 30 ug injection of DNSP-11
into the F344 rat substantia nigra, the broad distribution of the
compound through the substantia nigra (SN) region of the midbrain
was evident (FIG. 17, panels A, B). At higher magnification (FIG.
17 panels C, D) uptake of the peptide by neurons (arrows) could be
discerned. At very high magnification (FIG. 17 panel E),
punctate-immunoreactive staining of DNSP-11 was present in neuritic
processes, cytoplasm and the perinuclear area of the cell body
(arrows). The pattern of immunoreactivity was similar at 90 minutes
post injection (FIG. 17 panel B), with prominent labeling in
DNSP-11 in cells and neuritic processes (FIG. 17, panel D).
Immunostaining was more sensitive using fluorescent techniques
(FIG. 17, panel F), highlighting DNSP-11 immunoreactivity in the
cytoplasm and nuclei of neurons. The cells in F were double-labeled
for the neuronal marker NeuN and DNSP-11.
[0173] By improving mitochondrial functions in neurons and their
synapses, DNSP-11 treatment could significantly restore neural
networks affected in neurodegenerative diseases, including
Alzheimer's disease and Parkinson's disease, improving cognitive
functions in the former and improved motor functions in the
latter.
Example 14: The Neurorestorative Properties of DNSP-11 to Damaged
Dopamine Neurons in a Unilateral Rat Model of PD
[0174] Fischer 344 rats received dual-site unilateral injections of
6-OHDA to produce extensive destruction of the ascending
dopaminergic system that resulted in a greater than 99% depletion
of striatal dopamine content ipsilateral to the site of the 6-OHDA
injections. Rats were tested 3-4 weeks after the injection of
6-OHDA using low-dose (0.05 mg/kg, i.p.) apomorphine to induce
rotational behavior. In rats that rotated greater than 300 turns/60
minutes, 30 .mu.g of DNSP-11 was injected into the ipsilateral
substantia nigra. DNSP-11 produced a significant .about.50%
decrease in apomorphine-induced rotational behavior that was
significant 1 week after administration and this effect was
maintained for at least 4 weeks after DNSP-11 (FIG. 19A). At 5
weeks, the substantia nigra and striatum from each rat was analyzed
by high performance liquid chromatography coupled with
electrochemical detection. A single injection of DNSP-11 was found
to significantly increase levels of dopamine and the dopamine
metabolite, DOPAC, by .about.100% in the substantia nigra,
supporting that DNSP-11 has a powerful
neurotrophic-like/mitochondrogenic restorative effect on dopamine
neurons in this animal model of late stage PD (FIG. 19B).
Example 15: Protection of MN9D and B65 Cells from Mitochondrial
Toxins
[0175] MN9D cells and B65 cells were cultured in Dulbecco's
Modified Eagle's Medium (DMEM; 11995 (containing pyridoxol HCl);
Sigma, St. Louis, Mo.) supplemented with 10% fetal bovine serum
(HyClone, Logan, Utah), 50 U/mL penicillin and streptomycin. For
each assay the cells were treated with mitochondrial-specific
environmental toxins, i.e., MPP+, rotenone, and/or TaClo, and with
or without DNSP-11. After incubation with the toxins, the cells
were plated on 24-well poly-D-lysine plates (50,000 cells/well) for
TUNEL assay (as described below) or 100,000 cell/well for caspase-3
assay in DMEM medium with 1% (v/v) penicillin-streptomycin only (as
described below).
A. JC-1 Mitochondrial Membrane Potential Assay
[0176] MN9D and B65 cells were treated with either 50 nM, 100 nM,
250 nM, 500 nM, 1 .mu.M, 2.5 .mu.M or 5 .mu.M rotenone, 50 nM, 100
nM, 250 nM 1-methyl-4-phenylpyridinium (MPP+), or 10 .mu.M, 25
.mu.M, 50 .mu.M, 100 .mu.M, 150 .mu.M or 200 .mu.M
1-trichloromethyl-1,2,3,4-tetrahydro-.beta.-carboline (TaClo), for
1 to 12 hours and then incubated at 37.degree. C. in 5% CO.sub.2
following pretreatment (1 to 30 minutes) with or without 100 nM or
10 nM DNSP-11 After treatment with rotenone, MPP+ or TaClo and
incubation with DNSP-11, the cells were incubated for 30 minutes at
37.degree. C. in a 5% CO.sub.2 incubator in the presence of 10
.mu.M of the green fluorescent JC-1 (5,5',
6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-cabo-cyanine
iodine, T-3168 (Invitrogen)) and then washed in Locke's solution.
Optical measurements were acquired with excitation at 485 nm and
emission at 527 nm, and 590 nm. The levels of fluorescence at each
emission wavelengths were quantified and ratio of measurements was
assessed. The pertinent data are given as mean.+-.S.E.M. for mean
optical measurements. The values are expressed as percent of the
mean control values .+-.S.E.M. and analyzed using ANOVA.
[0177] FIG. 20 A-D depicts the mitochondrial potential of MN9D
cells (A) and B65 cells (B-D)) incubated in the presence MPP+,
rotenone, or TaClo with or without DNSP-11 and demonstrated that
the DNSP-11 protects the cells from the deleterious effects of
MPP+, rotenone and TaClo exposure.
B. Cellular Apoptosis: TUNEL Staining
[0178] Terminal deoxynucleotidyl transferase mediated X-dUTP nicked
end DNA labeling of cells (TUNEL staining) was used to assess cells
undergoing apoptosis. After treatment with either 50 nM, 100 nM or
250 nM MPP+, or 50 nM, 100 nM or 250 nM rotenone, or 10 .mu.M, 25
.mu.M or 50 .mu.M TaClo, for 1 to 12 hours at 37.degree. C. in 5%
CO.sub.2, following pretreatment with or without 10 nM or 100 nM
DNSP-11 for 1 to 30 minutes, MN9D cells were fixed and labeled to
assess degenerative nuclear changes as indicated by the extent of
high-molecular weight DNA strand breaks. The biotinylated
nucleotides are detected by using streptavidin-horseradish
peroxidase conjugate followed by the substrate, diaminobenzidine
(DAB). The enzyme reaction generates an insoluble colored
precipitate where DNA fragmentation has occurred. DAB-stained
samples were examined using a light microscope. Cell were counted
with 20.times. magnification (4 random fields/well), 4 wells per
group. Ratio between apoptotic cells and total cells was
calculated. This experiment was repeated 3 times and performed
using an Apoptosis detection TACS TdTKit (R&D System).
[0179] FIG. 20 E-G depicts the results of the TUNEL staining assay
of MN9D cells incubated with MPP, rotenone or TaClo with or without
DNSP-11 and demonstrates that DNSP-11 provides MN9D cells with
protection from the deleterious effects of MPP+, rotenone and TaClo
exposure.
C. Caspase-3 Activity Assay
[0180] B65 cells were plated on 24-well poly-D-lysine plates in
DMEM and 50 u/ml penicillin and streptomycin. Cells incubated in
either 50 nM, 100 nM, or 250 nM rotenone or 10 .mu.M, 25 .mu.M or
50 .mu.M TaClo for 1 to 12 hours at 37.degree. C. in 5% CO.sub.2,
following pretreatment (1 to 30 minutes) with or without 10 nM or
100 nM DNSP-11. The cells were then lysed and protein level
measured by BCA assay (BioRad). The protein level were normalized
for every experiment. The Enz Chek Caspase-3 Kit (Invitrogen) was
used to detect caspase-3 activity and fluorescence was read on
fluorescence reader (excitation/emission 496/520 nm). Data are
expressed as % of control and were repeated a minimum of three
times.
[0181] FIG. 20 H-I depicts the capase-3 activity of B65 cells
treated with rotenone or TaClo, with or without DNSP-11. FIG. 20
H-I demonstrates that DNSP-11 provides B65 cells with protection
from the deleterious effects of TaClo and rotenone exposure.
[0182] FIG. 20 A-I demonstrates that treatment with DNSP-11
provided significant protection to MN9D neuronal cells and B65
cells against MPP+, rotenone and/or TaClo toxicity, as demonstrated
by the reduction in TUNEL staining, reduced Capase 3 activity and
the increased level of mitochondrial potential detected in cells
incubated in the presence of DNSP-11. DNSP-11 alone had no
significant effect on MN9D or B65 as determined in the mitochodrial
potential assay, TUNEL staining assay or caspase-3 activity
assay.
Example 16: ERK1/2 Activation by GDNF and DNSP-11
[0183] It has been suggested that Erk activation affects
mitochondrial function. The results presented herein demonstration
that cells treated with GDNF and DNSP-11 have elevated levels of
activated Erk as determined by western blot analysis.
[0184] MN9D and B65 cell were cultured in DMEM; 11995 (containing
pyridoxol HCl; Sigma, St. Louis, Mo.) supplemented with 10% fetal
bovine serum (HyClone, Logan, Utah), 50 U/mL penicillin and
streptomycin with DNSP-11 (0.1 uM or 1 uM) or GDNF (50 ng/ml) for
20 minutes. The cells were then solubilized in
Triton-X-100/glycerol lysis buffer and subjected to electrophoresis
and western blotting as partially described previously (Jiang et
al., Mot Biol Cell 14:859-70 (2003)). To detect phosphorylated Erk
(#4377 Cell Signaling) and ERK (#4696 Cell Signaling) by
immunoblotting, the cells were directly lysed in the sample loading
buffer. Secondary IRDye 700X and IRDye800 conjugated, fluorescent
antibodies (Rockland Inc.) were used to detect signal with Odyssey
v3.0 scanning software. Several blots were analyzed to determine
the linear range of the fluorescence signals, and quantifications
were performed using densitometry analysis. Our results demonstrate
that like GDNF, DNSP-11 increases significantly the phosphorylation
of Erk1/2 (the ratio of phosphorylated to non-phosphorylated
Erk1/2) in MN9D and B65 cells (FIG. 21).
Example 17: Oxygen Consumption Rate
[0185] Complex I inhibitors have been demonstrated to increase
mitochondrial dysfunction, which leads to the formation of reactive
oxygen species (ROS), decrease in the formation of ATP, and
ultimately cell death. The ability of cells to respond to stress
under conditions of increased energy demand is, in large part,
influenced by the bioenergetic capacity of mitochondria. The
reserve respiration capacity is a measure of the cell's ability to
manage and overcome stress--such as that encountered during
exposure to toxins, injury, aging, and genetic abnormalities (Choi
et al., Journal of Neurochemistry 109:1179-1191.2009).
[0186] Real-time measurement of oxygen consumption rate (OCR) of
intact DNSP-11-treated MN9D cells, in the presence and absence of
Complex I toxins, rotenone 1-5 .eta.M or TaClo 100-150 .mu.M, were
performed utilizing the Seahorse XF-24 extracellular flux analyzer.
This instrument allows the simultaneous measurement of the
mitochondrial bioenergetics from 20 independent cell culture
samples, without the mitochondrial isolation (and thus higher
quantities of sample) needed for the standard (lower throughput)
Clark-type electrode chamber. Details regarding the methods used
for the Seahorse analysis were recently described in detail
(Sauerbeck et al., Journal of Neuroscience Methods 198:36-43 (2011)
incorporated herein by reference).
[0187] Briefly, following sensor preparation, calibration, and dose
optimization, the basal and maximal oxygen consumption rates (OCR)
were measured in intact MN9D neuronal cells in the absence and
presence of 1 .mu.M DNSP-11. As shown, in FIG. 22 DNSP-11 had no
significant effect on the basal OCR compared to control treatment.
Following electron transport chain uncoupling by 100 nM FCCP to
measure the maximal OCR, treatment of MN9D neurons with DNSP-11 had
nearly a 60% increase (p<0.001) versus control. The ratio
between the maximal and basal OCR is a measure of the reserve
respiratory capacity of neurons, thus treatment of DNSP-11
significantly increases the reserve respiratory capacity of MN9D
cells, primarily due to its effects on the maximal respiratory
capacity.
[0188] DNSP-11 also showed protection of the basal and maximal OCRs
from 100 .mu.M and 150 .mu.M TaClo (FIG. 23 A) and 1 nM, 2.5 nM and
5 nM rotenone (FIG. 23 B). Dosages were optimized for analysis by
the Seahorse XF24 flux analyzer. An increase in reserve respiration
capacity allow the mitochondria to effectively respond to the
mitochondrial-specific toxins disclosed above. An increase in
mitochondria reserve respiration capacity is consistent with the in
vitro protection from cytotoxins by DNSP-11 and with the in vivo
increases in dopamine release and metabolism observed for Fischer
344 rats after a single DNSP-11 injection into the substantia nigra
that are disclosed herein.
[0189] These results further demonstrate that ADNS peptides of this
invention provide mitochondrial protection and restoration from
various stresses, including environmental toxin exposure,
particularly toxins that inhibit mitochondrial Complex I activity.
In both MN9D and B65 dopaminergic neurons, DNSP-11 provides
significant protection against TaClo, MPP+, and rotenone as
evidenced by the of mitochondrial potentials, caspase-3 activity,
and TUNEL staining results presented herein. DNSP-11 also protects
cellular oxygen consumption rates from TaClo and rotenone exposure
and increases mitochondrial reserve respiration capacity in MN9D
neurons.
[0190] The evidence reported herein demonstrates that treatment
with the ADNS peptides of this invention, e.g., DNSP-11, improve
mitochondrial function and further that treatments with the ADNS
peptides of this invention, e.g., DNSP-11, promote behavioral
restoration in diseases such as Alzheimer's disease and Parkinson's
disease, and aging processes associated with dopinergic
deficiencies. The evidence reported herein also demonstrates that
treatment with the DNSP-11 peptide of this invention, prevents, or
lessens, the effects of mitochondrial toxins, particularly
mitochondrial complex I toxins, on mitochodrial and
mitochondria-containing cells.
[0191] The foregoing examples demonstrate that DNSP-11: is taken up
by neurons in the cortex, hippocampus and substantia nigra, areas
important in cognitive and motor functions; significantly increases
the expression of genes associated with mitochondrial functions in
the brain, including genes for proteins that protect mitochondria
from oxidative damage leading to functional deterioration, and;
increases energy production in brain mitochondria for extended
periods. DNSP-11 was shown to protect mitochodria from the
deleterious effects of toxins such as MPP+, rotenone and TaClo
which target the mitochondrial complex I enzyme activity.
[0192] Increased energy production in mitochondria in synapses is
posited to promote restoration of neural circuitry leading to
restoration of cognitive and motor functions.
[0193] While the present invention has been described with
reference to specific embodiments, this application is intended to
cover those various changes and substitutions that may be made by
those of ordinary skill in the art without departing from the
spirit and scope of the appended claims.
[0194] The publications discussed herein are provided solely for
their disclosure prior to the filing date of the present
application. Nothing herein is to be construed as an admission that
the present invention is not entitled to antedate such publication
by virtue of prior invention. Further, the dates of publication
provided may be different from the actual publication dates, which
may need to be independently confirmed. All publications cited
herein are hereby incorporated by reference in their entirety.
Sequence CWU 1
1
151134PRTHomo sapiens 1Ser Pro Asp Lys Gln Met Ala Val Leu Pro Arg
Arg Glu Arg Asn Arg 1 5 10 15 Gln Ala Ala Ala Ala Asn Pro Glu Asn
Ser Arg Gly Lys Gly Arg Arg 20 25 30 Gly Gln Arg Gly Lys Asn Arg
Gly Cys Val Leu Thr Ala Ile His Leu 35 40 45 Asn Val Thr Asp Leu
Gly Leu Gly Tyr Glu Thr Lys Glu Glu Leu Ile 50 55 60 Phe Arg Tyr
Cys Ser Gly Ser Cys Asp Ala Ala Glu Thr Thr Tyr Asp 65 70 75 80 Lys
Ile Leu Lys Asn Leu Ser Arg Asn Arg Arg Leu Val Ser Asp Lys 85 90
95 Val Gly Gln Ala Cys Cys Arg Pro Ile Ala Phe Asp Asp Asp Leu Ser
100 105 110 Phe Leu Asp Asp Asn Leu Val Tyr His Ile Leu Arg Lys His
Ser Ala 115 120 125 Lys Arg Cys Gly Cys Ile 130 217PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 2Glu
Arg Asn Arg Gln Ala Ala Ala Ala Asn Pro Glu Asn Ser Arg Gly 1 5 10
15 Lys 35PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 3Phe Pro Leu Pro Ala 1 5411PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 4Pro
Pro Glu Ala Pro Ala Glu Asp Arg Ser Leu 1 5 10 5402DNAHomo
sapiensCDS(1)..(402) 5tca cca gat aaa caa atg gca gtg ctt cct aga
aga gag cgg aat cgg 48Ser Pro Asp Lys Gln Met Ala Val Leu Pro Arg
Arg Glu Arg Asn Arg1 5 10 15 cag gct gca gct gcc aac cca gag aat
tcc aga gga aaa ggt cgg aga 96Gln Ala Ala Ala Ala Asn Pro Glu Asn
Ser Arg Gly Lys Gly Arg Arg 20 25 30 ggc cag agg ggc aaa aac cgg
ggt tgt gtc tta act gca ata cat tta 144Gly Gln Arg Gly Lys Asn Arg
Gly Cys Val Leu Thr Ala Ile His Leu 35 40 45 aat gtc act gac ttg
ggt ctg ggc tat gaa acc aag gag gaa ctg att 192Asn Val Thr Asp Leu
Gly Leu Gly Tyr Glu Thr Lys Glu Glu Leu Ile 50 55 60 ttt agg tac
tgc agc ggc tct tgc gat gca gct gag aca acg tac gac 240Phe Arg Tyr
Cys Ser Gly Ser Cys Asp Ala Ala Glu Thr Thr Tyr Asp65 70 75 80aaa
ata ttg aaa aac tta tcc aga aat aga agg ctg gtg agt gac aaa 288Lys
Ile Leu Lys Asn Leu Ser Arg Asn Arg Arg Leu Val Ser Asp Lys 85 90
95 gta ggg cag gca tgt tgc aga ccc atc gcc ttt gat gat gac ctg tcg
336Val Gly Gln Ala Cys Cys Arg Pro Ile Ala Phe Asp Asp Asp Leu Ser
100 105 110 ttt tta gat gat aac ctg gtt tac cat att cta aga aag cat
tcc gct 384Phe Leu Asp Asp Asn Leu Val Tyr His Ile Leu Arg Lys His
Ser Ala 115 120 125 aaa agg tgt gga tgt atc 402Lys Arg Cys Gly Cys
Ile 130 6211PRTHomo sapiens 6Met Lys Leu Trp Asp Val Val Ala Val
Cys Leu Val Leu Leu His Thr 1 5 10 15 Ala Ser Ala Phe Pro Leu Pro
Ala Gly Lys Arg Pro Pro Glu Ala Pro 20 25 30 Ala Glu Asp Arg Ser
Leu Gly Arg Arg Arg Ala Pro Phe Ala Leu Ser 35 40 45 Ser Asp Ser
Asn Met Pro Glu Asp Tyr Pro Asp Gln Phe Asp Asp Val 50 55 60 Met
Asp Phe Ile Gln Ala Thr Ile Lys Arg Leu Lys Arg Ser Pro Asp 65 70
75 80Lys Gln Met Ala Val Leu Pro Arg Arg Glu Arg Asn Arg Gln Ala
Ala 85 90 95 Ala Ala Asn Pro Glu Asn Ser Arg Gly Lys Gly Arg Arg
Gly Gln Arg 100 105 110 Gly Lys Asn Arg Gly Cys Val Leu Thr Ala Ile
His Leu Asn Val Thr 115 120 125 Asp Leu Gly Leu Gly Tyr Glu Thr Lys
Glu Glu Leu Ile Phe Arg Tyr 130 135 140 Cys Ser Gly Ser Cys Asp Ala
Ala Glu Thr Thr Tyr Asp Lys Ile Leu 145 150 155 160Lys Asn Leu Ser
Arg Asn Arg Arg Leu Val Ser Asp Lys Val Gly Gln 165 170 175 Ala Cys
Cys Arg Pro Ile Ala Phe Asp Asp Asp Leu Ser Phe Leu Asp 180 185 190
Asp Asn Leu Val Tyr His Ile Leu Arg Lys His Ser Ala Lys Arg Cys 195
200 205 Gly Cys Ile 210 7192PRTHomo sapiens 7Phe Pro Leu Pro Ala
Gly Lys Arg Pro Pro Glu Ala Pro Ala Glu Asp 1 5 10 15 Arg Ser Leu
Gly Arg Arg Arg Ala Pro Phe Ala Leu Ser Ser Asp Ser 20 25 30 Asn
Met Pro Glu Asp Tyr Pro Asp Gln Phe Asp Asp Val Met Asp Phe 35 40
45 Ile Gln Ala Thr Ile Lys Arg Leu Lys Arg Ser Pro Asp Lys Gln Met
50 55 60 Ala Val Leu Pro Arg Arg Glu Arg Asn Arg Gln Ala Ala Ala
Ala Asn 65 70 75 80Pro Glu Asn Ser Arg Gly Lys Gly Arg Arg Gly Gln
Arg Gly Lys Asn 85 90 95 Arg Gly Cys Val Leu Thr Ala Ile His Leu
Asn Val Thr Asp Leu Gly 100 105 110 Leu Gly Tyr Glu Thr Lys Glu Glu
Leu Ile Phe Arg Tyr Cys Ser Gly 115 120 125 Ser Cys Asp Ala Ala Glu
Thr Thr Tyr Asp Lys Ile Leu Lys Asn Leu 130 135 140 Ser Arg Asn Arg
Arg Leu Val Ser Asp Lys Val Gly Gln Ala Cys Cys 145 150 155 160Arg
Pro Ile Ala Phe Asp Asp Asp Leu Ser Phe Leu Asp Asp Asn Leu 165 170
175 Val Tyr His Ile Leu Arg Lys His Ser Ala Lys Arg Cys Gly Cys Ile
180 185 190 88PRTArtificial SequenceDescription of Artificial
Sequence Synthetic peptide 8Phe Pro Leu Pro Ala Gly Lys Arg 1 5
914PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 9Pro Pro Glu Ala Pro Ala Glu Asp Arg Ser Leu Gly
Arg Arg 1 5 10 1020PRTArtificial SequenceDescription of Artificial
Sequence Synthetic peptide 10Glu Arg Asn Arg Gln Ala Ala Ala Ala
Asn Pro Glu Asn Ser Arg Gly 1 5 10 15 Lys Gly Arg Arg
20116PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 11Phe Pro Leu Pro Ala Gly 1 5 1212PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 12Pro
Pro Glu Ala Pro Ala Glu Asp Arg Ser Leu Gly 1 5 10
1318PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 13Glu Arg Asn Arg Gln Ala Ala Ala Ala Asn Pro Glu
Asn Ser Arg Gly 1 5 10 15 Lys Gly 1416PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 14Lys
Arg Pro Pro Glu Ala Pro Ala Glu Asp Arg Ser Leu Gly Arg Arg 1 5 10
15 1522PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 15Arg Arg Glu Arg Asn Arg Gln Ala Ala Ala Ala Asn
Pro Glu Asn Ser 1 5 10 15 Arg Gly Lys Gly Arg Arg 20
* * * * *