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Mimicking synuclein toxicity in plant cells to identify novel neuroprotective leads

Award Information
Agency: Department of Health and Human Services
Branch: National Institutes of Health
Contract: 1R43NS108804-01
Agency Tracking Number: R43NS108804
Amount: $231,474.00
Phase: Phase I
Program: SBIR
Solicitation Topic Code: NINDS
Solicitation Number: PA17-302
Timeline
Solicitation Year: 2017
Award Year: 2018
Award Start Date (Proposal Award Date): 2018-09-01
Award End Date (Contract End Date): 2019-08-31
Small Business Information
KTRDC-UK 1401 UNVERSITY DR
Lexington, KY 40546-0001
United States
DUNS: 196165877
HUBZone Owned: No
Woman Owned: No
Socially and Economically Disadvantaged: No
Principal Investigator
 JOHN LITTLETON
 (859) 255-6757
 jlittlet@uky.edu
Business Contact
 CINDY BURKLOW
Phone: (859) 257-1127
Email: cindy_burklow@yahoo.com
Research Institution
N/A
Abstract

Abstract
Alpha synucleinASYNis believed to play an important role in the pathology of several neurodegenerative
conditionsincluding some forms of Parkinsonandapos s diseaseDementia with Lewy Bodiesand Multiple Systems
AtrophyThe most recent hypothesis is that the ASYN proteinsparticularly genetic variants such as AT that
are prone to misfoldingare cleaved by the lysosomal enzymeasparagine endopeptidaseAEPto generate
peptides that promote ASYN aggregation and initiate programmed cell deathPCDin vulnerable neuronsZhang et alInhibition of AEPand of ASYN aggregationare therefore prime molecular targets for
pharmacotherapy of thesesynucleinopathiessee Brundin et aland maybe other neurodegenerative
diseasesChemical synthesis has yielded few leadsand this proposal will use a novel plant biotech platform
to generate active compoundsIn this approachplant root cells are transformed by expression of human
neuronal proteins to make them susceptible to a specific mechanism of neuronal toxicityMutants of these
transgenic plant cells are then selected for survival when exposed to this neurotoxic mechanismThis
mutagenesis and survival selectionevolvesplant secondary metabolism toward biosynthesis of metabolites
that inhibit the neurotoxic mechanismProof of concept used expression of the human dopamine transporterhDATin plant cellsThis makes the plant cells highly susceptible to cytotoxicity induced by the dopaminergic
neurotoxinMPPwhich is accumulated by the hDATWhen transgenichDATmutants are selected for
survival in MPPthe resulting sub population includes many individuals that overproduce known or novel
metabolites that inhibit the hDATand or the cytotoxic mechanisms of MPPBrown et alAs regards
the AEP ASYN mechanism of neurotoxicityplant cells naturally contain a homolog to lysosomal AEPwhichlike the human neuronal AEPis linked to PCDHatsugai et alMetabolites that regulate this process
almost certainly exist in plantsand so mutant plant cells that survive AEP activation should include many that
overproduce natural inhibitors of plantp AEPBecause plant and humanh AEP are homologsthese
metabolites are potential neuroprotective leadsHoweverplant cells do not naturally contain homologs of
humanh ASYN soto mimic the proposed mechanism of synucleinopathies we will create transgenic plant
cells that express the hASYN variant ATBecause pAEP has similar substrate specificity to hAEPand
because the peptides produced by hASYN AT cleavage are highly cytotoxicthese transgenichASYNATplant cells should show increased susceptibility to PCD when pAEP is activatedto be established in
Phase IConsequently transgenichASYN ATmutants that survive AEP activation should include many
individual clones in which inhibitors of pAEPor of peptide induced hASYN aggregationare over producedIn
addition tonaturalmetabolitesmutation and selection shouldevolveplant secondary metabolism toward
novel metabolites with greater inhibitory activityThis will be established in Phase II using conventional in vitro
screensidentifying active metabolites by assay guided fractionationThe objective is to develop these active
plant metabolites as therapeutic agentsor leads for synthetic modificationby the applicants in partnership
with a major pharmaceutical companyThe application of the proprietary biotechnology to these important
targets will also strengthen its commercial importance as a plant drug discovery platform Project narrative
Several human neurodegenerative diseasesincluding familial Parkinson s diseaseshare a mechanism in which
the enzymatic modification and subsequent aggregation of a nerve cell protein called alpha synuclein kills nerve
cellsPlant root cells contain a similar enzymebut they do not contain alpha synucleinBy creating plant cells
expressing human alpha synuclein the applicants will be able to seek novel plant metabolites that inhibit this
neurotoxic process and that will lead to novel drugs to treat these devastating neurodegenerative diseases

* Information listed above is at the time of submission. *

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