부산대학교 도서관

Exposure of SH-SY5Y neuroblastoma or rat cortical neurons to diethylenetriamine–NO (DETA–NO) rapidly depolarized mitochondria. In SH-SY5Y DETA–NO activated caspase 3 and produced cell death. Mitochondrial depolarization in SH-SY5Y was visualized both with JC-1 accumulation and as dequenching of calcein fluorescence in mitochondria initially loaded with calcein-AM and tetramethylrhodamine methyl ester (TMRM). Calcein/TMRM-visualized mitochondrial depolarization was prevented by cyclosporin A (CsA) or ∼two-fold increased levels of BclXL protein. Dynamic imaging of mitochondrial potential (ΔψM) with TMRM showed that DETA–NO induced cycles of mitochondrial depolarization/repolarization (“flickering”). Fifteen–30 min of DETA–NO exposure caused high-frequency flickering with small peak size; 2 h of DETA–NO produced large peaks with prolonged depolarization. NO-induced flickering but not that from Bax was blocked by the calcium uniporter antagonist Ru360. Our findings show rapid-onset, dynamic regulation of ΔψM by NO, implying that neuroprotective therapies for brain ischemia target cell death processes downstream of effects of NO on mitochondria. [Copyright &y& Elsevier]