title: Monocyte-mediated rotenone neurotoxicity towards human neuroblastoma SH-SY5Y: role of mitogen-activated protein kinases.
abstract: Increasing evidence has suggested an important role for rotenone in the pathogenesis of Parkinson's disease (PD). In this report, sequential linking of two culture systems, monocytic THP-1 cell line and SH-SY5Y neuroblastoma, was utilized. The supernatant from rotenone-stimulated THP-1 cells was used as the incubating medium for the second culture which adopted cells of the SH-SY5Y neuroblastoma. At 6.25-50 nM, concentrations that were nontoxic to SH-SY5Y directly, rotenone induced dose-dependent cell death on SH-SY5Y through stimulating monocyte THP-1 within a period of 48 h. Cytotoxicity was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Hoechst 33258 staining revealed that the treatment of SH-SY5Y with rotenone-stimulated THP-1 supernatant resulted in condensed nuclei and a decrease in cell size. Apoptotic rate measured by flow cytometric analysis indicated that at 25 and 50 nM, the percentage of apoptotic SH-SY5Y cells accumulated to 31.5% and 37.0% respectively. We further investigated whether rotenone (50 nM) activated mitogen-activated protein kinase (MAPK) cascades, and found it had effect on p38 MAPK and ERK in THP-1 cells, but not JNK. Pretreatment of THP-1 cells with the MAPK kinase inhibitor, PD98059, inhibited THP-1 cell-mediated rotenone neurotoxicity towards SH-SY5Y, whereas the p38 MEK inhibitor, SB203580, had no effect. These results suggested that activation of microglia intracellular signaling pathway may also involve in microglia-enhanced rotenone neurotoxicity.
authors.affiliation: Department of Pharmacology, Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China.
authors.forename: Fei-Li
authors.initials: FL
authors.lastname: Zhao
authors.forename: Jing-Hui
authors.initials: JH
authors.lastname: Hu
authors.forename: Xing-Zu
authors.initials: XZ
authors.lastname: Zhu
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002450:Cell Communication; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009000:Monocytes / Q000502:physiology*; D009447:Neuroblastoma; D012402:Rotenone / Q000633:toxicity*
chemical_list: D004791:Enzyme Inhibitors; D012402:Rotenone; D020928:Mitogen-Activated Protein Kinases