Neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis (ALS) and prion protein diseases all feature misfolded proteins and their aggregates, which appear to play a role in disease pathogenesis. However, the mechanism(s) and pathways by which misfolded proteins couple to the cell death program is poorly understood. We have recently found that misfolded proteins, which trigger endoplasmic reticulum stress (ER stress), induce a novel intrinsic apoptotic pathway that is independent of Apaf-1 and mitochondria (Rao et al., 2001; Rao et al., 2002a; Rao et al., 2002b). In order to define the molecular requirements of this pathway, we have developed a cell-free system of ER stress-induced apoptosis. In this system, microsomes isolated from cells lacking ER stress fail to activate cytosolic extracts, whereas microsomes isolated from cells undergoing ER stress activate caspases-3 and -9 in cytosolic extracts. Using a set of complementary approaches including protein purification procedures, 2D MALDI-TOF/nano-ESMS (two-dimensional matrix-assisted laser desorption ionization-time of flight/nanoelectrospray mass spectrometry), immunodepletion of candidate proteins, and an RNA interference (RNAi) approach, we have identified the initial candidate biochemical mediators of this novel apoptotic pathway, and here we propose to continue to identify the components of this ER stress-induced apoptotic pathway. Because an understanding of the relationship between the accumulation of misfolded proteins, cellular stress response, and cell death programs should facilitate the development of new therapeutic strategies for neurodegenerative disorders that feature misfolded proteins, we propose to integrate the findings from our cell work with an animal model of ALS, and address the following questions: (1) What are the proteins that mediate ER stress-induced cell death? (2) Within the set of relevant proteins that are differentially expressed, what are the crucial proteins for cell death induction? (3) Is there evidence of activation of the ER stress-induced apoptotic pathway in transgenic mice expressing mutant (vs. wild type) CuZnSOD? (4) Does recombinant mutant CuZnSOD protein induce normal organelles to initiate a specific cell death pathway? We believe that the results of the proposed experiments may offer insight into the pathogenesis of neurodegenerative disorders that feature misfolded proteins, and should enhance the usefulness of our system for development of therapeutics.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
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Molecular, Cellular and Developmental Neurosciences 2 (MDCN)
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Murphy, Diane
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Buck Institute for Age Research
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Zhang, Junli; Spilman, Patricia; Chen, Sylvia et al. (2013) The small co-chaperone p23 overexpressing transgenic mouse. J Neurosci Methods 212:190-4
Rao, Rammohan V; Descamps, Olivier; John, Varghese et al. (2012) Ayurvedic medicinal plants for Alzheimer's disease: a review. Alzheimers Res Ther 4:22
Sultana, Rukhsana; Robinson, RenĂ£ A S; Lange, Miranda Bader et al. (2012) Do proteomics analyses provide insights into reduced oxidative stress in the brain of an Alzheimer disease transgenic mouse model with an M631L amyloid precursor protein substitution and thereby the importance of amyloid-beta-resident methionine 35 in Alz Antioxid Redox Signal 17:1507-14
Poksay, Karen S; Banwait, Surita; Crippen, Danielle et al. (2012) The small chaperone protein p23 and its cleaved product p19 in cellular stress. J Mol Neurosci 46:303-14
Mukherjee, Abhisek; Soto, Claudio (2011) Role of calcineurin in neurodegeneration produced by misfolded proteins and endoplasmic reticulum stress. Curr Opin Cell Biol 23:223-30
Robinson, R A S; Lange, M B; Sultana, R et al. (2011) Differential expression and redox proteomics analyses of an Alzheimer disease transgenic mouse model: effects of the amyloid-? peptide of amyloid precursor protein. Neuroscience 177:207-22
Poksay, Karen S; Madden, David T; Peter, Anna K et al. (2011) Valosin-containing protein gene mutations: cellular phenotypes relevant to neurodegeneration. J Mol Neurosci 44:91-102
Zhang, Junli; Rao, Rammohan V; Spilman, Patricia et al. (2011) Endogenously EGFP-Labeled Mouse Embryonic Stem Cells. Aging Dis 2:18-29
Butterfield, D Allan; Galvan, Veronica; Lange, Miranda Bader et al. (2010) In vivo oxidative stress in brain of Alzheimer disease transgenic mice: Requirement for methionine 35 in amyloid beta-peptide of APP. Free Radic Biol Med 48:136-44
Chinta, Shankar J; Poksay, Karen S; Kaundinya, Gaayatri et al. (2009) Endoplasmic reticulum stress-induced cell death in dopaminergic cells: effect of resveratrol. J Mol Neurosci 39:157-68

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