title: Role of reactive oxygen species in extracellular signal-regulated protein kinase phosphorylation and 6-hydroxydopamine cytotoxicity.
abstract: A number of reports indicate the potential for redox signalling via extracellular signal-regulated protein kinases (ERK) during neuronal injury. We have previously found that sustained ERK activation contributes to toxicity elicited by 6-hydroxydopamine (6-OHDA) in the B65 neuronal cell line. To determine whether reactive oxygen species (ROS) play a role in mediating ERK activation and 6-OHDA toxicity, we examined the effects of catalase, superoxide dismutase (SOD1), and metalloporphyrin antioxidants ('SOD mimetics') on 6-OHDA-treated cells. We found that catalase and metalloporphyrin antioxidants not only conferred protection against 6-OHDA but also inhibited development of sustained ERK phosphorylation in both differentiated and undifferentiated B65 cells. However, exogenously added SOD1 and heat-inactivated catalase had no effect on either toxicity or sustained ERK phosphorylation. This correlation between antioxidant protection and inhibition of 6-OHDA-induced sustained ERK phosphorylation suggests that redox regulation of ERK signalling cascades may contribute to neuronal toxicity.
authors.affiliation: Department of Pathology, Division of Neuropathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Kulich
authors.forename: Charleen T
authors.initials: CT
authors.lastname: Chu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D008665:Metalloporphyrins / Q000378:metabolism / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects*; D016627:Oxidopamine / Q000633:toxicity*; D010766:Phosphorylation; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D008665:Metalloporphyrins; D017382:Reactive Oxygen Species; D016627:Oxidopamine; D002374:Catalase; D013482:Superoxide Dismutase; D020928:Mitogen-Activated Protein Kinases