Much of the neuronal damage resulting from ischemia is not immediate but delayed and is thought to be due, in addition to excitotoxic cell death, to overwhelming oxidative stress and subsequent apoptosis. Similarly, other debilitating diseases such as Parkinson's Disease and Alzheimer's Disease have been linked with chronic oxidative stress and neurodegeration. It is the purpose of this proposal to investigate the signaling events that occur during oxidative stress in neurons and to conceive of approaches that may prevent neuronal death in this context. Glutamate-induced oxidative toxicity, both in the mouse hippocampal cell line, HT22, and primary immature neuronal cortical neurons, is a well-studied model of oxidative stress and neuronal cell death. Little is known about the role of the mitogen-activated protein kinase (MAPK) phosphatases (MKPs) during oxidative stress in neurons. We plan to investigate changes of expression and activity of MKPs during glutamate-induced oxidative stress in both HT22 and primary cortical neurons. In addition, MKP3 and its catalytically inactive mutant, MKP3 C293S, will be transfected into both cell systems in order to investigate the ability of this phosphatase to abrogate glutamate-induced oxidative toxicity. Further experiments involving the construction of a ligand- inducible MKP3-estrogen receptor ligand-binding domain (MKP3-ER LBD) will allow the temporal control of MKP3 activity in response to tamoxifen.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Individual Predoctoral NRSA for M.D./Ph.D. Fellowships (ADAMHA) (F30)
Project #
5F30NS043824-04
Application #
6933906
Study Section
NST-2 Subcommittee (NST)
Program Officer
Golanov, Eugene V
Project Start
2002-06-01
Project End
2006-05-31
Budget Start
2005-06-01
Budget End
2006-05-31
Support Year
4
Fiscal Year
2005
Total Cost
$45,094
Indirect Cost
Name
University of Pittsburgh
Department
Neurology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Dum, Richard P; Levinthal, David J; Strick, Peter L (2009) The spinothalamic system targets motor and sensory areas in the cerebral cortex of monkeys. J Neurosci 29:14223-35
Levinthal, David J; Defranco, Donald B (2005) Reversible oxidation of ERK-directed protein phosphatases drives oxidative toxicity in neurons. J Biol Chem 280:5875-83
Chu, Charleen T; Levinthal, David J; Kulich, Scott M et al. (2004) Oxidative neuronal injury. The dark side of ERK1/2. Eur J Biochem 271:2060-6
Levinthal, David J; DeFranco, Donald B (2004) Transient phosphatidylinositol 3-kinase inhibition protects immature primary cortical neurons from oxidative toxicity via suppression of extracellular signal-regulated kinase activation. J Biol Chem 279:11206-13