Glutathione depletion is the earliest detectablebiochemicalevent in the Parkinsonian substantia nigra (SN), occurring prior to selective loss of mitochondrial complex I (CI)activity associated with the disease. We have previously demonstrated that down-regulation of total glutathione (GSH + GSSG) levels in cultured dopaminergic cell lines results in decreased mitochondrial function linked to a selective decrease in CI activity (Jha et al.,2000). Loss of CI activity following acute glutathione depletion appears to be due to reversible nitrosylation of protein subunits comprisingthis complex.The effects of prolonged chronic glutathione depletion on CI activity in dopaminergic cells, however, are unknown but may involve additional, irreversible oxidative events. A major goal of our project is to assess CI inhibition in our dopaminergic cell model at various times and levels of glutathione depletion in order to identify the limitsof function vs. dysfunction including the thresholds for reversible vs. irreversible inhibition as well as the oxidant species and protein targets involved. Once such targets have been identified, we will assess the presence of similar alterations in a newly constructed dox-inducible antiGSH transgenic mouse model following titration of glutathione levels within SN dopaminergic neurons in vivo as a model for molecular events associated with Parkinson's disease. Acute reduction in glutathione in our cell model also results in inhibition of the GSSG reducing enzyme glutathione reductase (GluRd) and up-regulation of the enzyme g-glutamyl transpeptidase (GGT) which breaks down extracellular GSHto substrates which are transported back into the cell for glutathione synthesis. The former may contribute to the detrimental effects of glutathione depletion on mitochondrial function while the latter appears to be a compensatory event. We will also explore the molecular mechanisms involved in these molecular alterations following titration of glutathione pools including the oxidants and the enzyme targets involved and if/how these changes modify mitochondrial function. We will assess the effects of both transgenic GSSG Rd and GGTexpression on CI activity and mitochondrial function in our dopaminergic cell model to see if they act to attenuate any detrimental mitochondrial effects.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Program Projects (P01)
Project #
5P01AG025901-05
Application #
8234011
Study Section
Special Emphasis Panel (ZAG1)
Project Start
Project End
2013-02-28
Budget Start
2011-03-01
Budget End
2013-02-28
Support Year
5
Fiscal Year
2011
Total Cost
$403,975
Indirect Cost
Name
Buck Institute for Age Research
Department
Type
DUNS #
786502351
City
Novato
State
CA
Country
United States
Zip Code
94945
Leonoudakis, Dmitri; Rane, Anand; Angeli, Suzanne et al. (2017) Anti-Inflammatory and Neuroprotective Role of Natural Product Securinine in Activated Glial Cells: Implications for Parkinson's Disease. Mediators Inflamm 2017:8302636
Siddiqui, Almas; Rane, Anand; Rajagopalan, Subramanian et al. (2016) Detrimental effects of oxidative losses in parkin activity in a model of sporadic Parkinson's disease are attenuated by restoration of PGC1alpha. Neurobiol Dis 93:115-20
Siddiqui, Almas; Bhaumik, Dipa; Chinta, Shankar J et al. (2015) Mitochondrial Quality Control via the PGC1?-TFEB Signaling Pathway Is Compromised by Parkin Q311X Mutation But Independently Restored by Rapamycin. J Neurosci 35:12833-44
Chinta, Shankar J; Woods, Georgia; Rane, Anand et al. (2015) Cellular senescence and the aging brain. Exp Gerontol 68:3-7
Velarde, Michael C; Demaria, Marco; Melov, Simon et al. (2015) Pleiotropic age-dependent effects of mitochondrial dysfunction on epidermal stem cells. Proc Natl Acad Sci U S A 112:10407-12
Laberge, Remi-Martin; Sun, Yu; Orjalo, Arturo V et al. (2015) MTOR regulates the pro-tumorigenic senescence-associated secretory phenotype by promoting IL1A translation. Nat Cell Biol 17:1049-61
Lieu, Christopher A; Dewey, Colleen M; Chinta, Shankar J et al. (2014) Lithium prevents parkinsonian behavioral and striatal phenotypes in an aged parkin mutant transgenic mouse model. Brain Res 1591:111-7
Brand, M D; Orr, A L; Perevoshchikova, I V et al. (2013) The role of mitochondrial function and cellular bioenergetics in ageing and disease. Br J Dermatol 169 Suppl 2:1-8
Lieu, Christopher A; Chinta, Shankar J; Rane, Anand et al. (2013) Age-related behavioral phenotype of an astrocytic monoamine oxidase-B transgenic mouse model of Parkinson's disease. PLoS One 8:e54200
McQuaker, Stephen J; Quinlan, Casey L; Caldwell, Stuart T et al. (2013) A prototypical small-molecule modulator uncouples mitochondria in response to endogenous hydrogen peroxide production. Chembiochem 14:993-1000

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