Changes in endoplasmic reticulum stress proteins and aldolase A in cells exposed to dopamine

• Published in: Journal of neurochemistry Vol. 106; no. 1; pp. 333 - 346
• Main Authors: Dukes, April A, Van Laar, Victor S, Cascio, Michael, Hastings, Teresa G
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2008; Blackwell Publishing Ltd; Blackwell
• Subjects: 2D difference in-gel electrophoresis; Animals; Biochemistry; Biological and medical sciences; Calreticulin - drug effects; Calreticulin - metabolism; Cellular biology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; dopamine; Dopamine - metabolism; Dopamine - pharmacology; Down-Regulation - drug effects; Down-Regulation - physiology; Electrophoresis, Gel, Two-Dimensional; Endoplasmic Reticulum - drug effects; Endoplasmic Reticulum - metabolism; endoplasmic reticulum stress; Fluorescent Dyes; Fructose-Bisphosphate Aldolase - drug effects; Fructose-Bisphosphate Aldolase - metabolism; Heat-Shock Proteins - drug effects; Heat-Shock Proteins - metabolism; HSP70 Heat-Shock Proteins - drug effects; HSP70 Heat-Shock Proteins - metabolism; Mass Spectrometry; Medical sciences; Membrane Glycoproteins - drug effects; Membrane Glycoproteins - metabolism; Membrane Proteins - drug effects; Membrane Proteins - metabolism; mitochondria; Molecular Chaperones - drug effects; Molecular Chaperones - metabolism; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Neurons - drug effects; Neurons - metabolism; Oxidation; Oxidative Stress - drug effects; Oxidative Stress - physiology; Parkinson Disease - metabolism; Parkinson Disease - physiopathology; Parkinson's disease; PC12; PC12 Cells; Protein Disulfide-Isomerases - drug effects; Protein Disulfide-Isomerases - metabolism; Protein Folding; Proteins - drug effects; Proteins - metabolism; proteomics; Rats; Up-Regulation - drug effects; Up-Regulation - physiology; Modification; Oxidative stress; Toxicity; Parkinson disease; 2D difference in-gel electrophoresis; endoplasmic reticulum stress; Unfolded protein response; Aggregation; Mitochondria; Degenerative disease; Oxidation; Nervous system diseases; Dopamine; proteomics; Catecholamine; Metabolism; In vitro; Protein; Cerebral disorder; PC12; Dysfunction; Central nervous system disease; Neurotransmitter; Endoplasmic reticulum; Extrapyramidal syndrome
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2008.05392.x

In Parkinson's disease, oxidative stress is implicated in protein misfolding and aggregation, which may activate the unfolded protein response by the endoplasmic reticulum (ER). Dopamine (DA) can initiate oxidative stress via H₂O₂ formation by DA metabolism and by oxidation into DA quinone. We have previously shown that DA quinone induces oxidative protein modification, mitochondrial dysfunction in vitro, and dopaminergic cell toxicity in vivo and in vitro. In this study, we used cysteine- and lysine-reactive fluorescent dyes with 2D difference in-gel electrophoresis, mass spectrometry, and peptide mass fingerprint analysis to identify proteins in PC12 cell mitochondrial-enriched fractions that were altered in abundance following DA exposure (150 μM, 16 h). Quantitative changes in proteins labeled with fluorescent dyes indicated increases in a subset of proteins after DA exposure: calreticulin, ERp29, ERp99, Grp58, Grp78, Grp94 and Orp150 (149-260%), and decreased levels of aldolase A (39-42%). Changes in levels of several proteins detected by 2D difference in-gel electrophoresis were confirmed by western blot. Using this unbiased proteomics approach, our findings demonstrated that in PC12 cells, DA exposure leads to a cellular response indicative of ER stress prior to the onset of cell death, providing a potential link between DA and the unfolded protein response in the pathogenesis of Parkinson's disease.