Inhibitory effect of nicardipine on rotenone-induced apoptosis in SH-SY5Y human neuroblastoma cells

Abstract

Previous studies have demonstrated that calcium channel blockers have protective effects on damaged brains. In the present study, the protective effect of the calcium channel blocker nicardipine against rotenone-induced apoptosis in SH-SY5Y human neuroblastoma cells was investigated, focusing on mitogen-activated protein kinases (MAPKs) and caspase (CASP)-mediated apoptotic events. Nicardipine was found to decrease rotenone-induced apoptosis through 4,6-diamidino-2-phenylindole staining and the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. In addition, nicardipine was identified to inhibit rotenone-induced elevation of intracellular Ca2+ concentration measured using the Fluo-4 AM fluorescent dye. Rotenone increased phosphorylation of c-Jun NH2-terminal kinase (JNK) and p38 MAPK, whereas nicardipine blocked these increases. Nicardipine also prevented clownregulation of B-cell CLL/lymphoma 2 and upregulation of Bc12-associated X protein by rotenone. Furthermore, nicardipine abrogated cleavage of CASP9 and 3 and poly (ADP-ribose) polymerase-1 by rotenone and CASP3 enzyme activity in rotenone-treated cells. These results indicate that nicardipine exerts a protective effect against rotenone-induced apoptosis in SH-SY5Y cells, inhibiting phosphorylation of JNK and p38 MAPK and activation of CASPs.