Bcl-xL prevents staurosporine-induced hepatocyte apoptosis by restoring protein kinase B/mitogen-activated protein kinase activity and mitochondria integrity.
Our study reports that staurosporine induces apoptosis in cultured rat hepatocytes in a dose- and time-dependent fashion. Staurosporine induced apparent cleavage of caspase-8, caspase-9, and caspase-3. The release of cytochrome c from mitochondria, and Bid activation were also detected in staurosporine-treated primary hepatocytes. These results suggest that mitochondria-mediated cell death signaling may be involved in staurosporine-induced hepatocyte apoptosis. Bcl-x(L) overexpression protected from "loss of" mitochondrial transmembrane potential and prevented staurosporine-induced caspase-3 and caspase-8 cleavage. Overexpression of constitutively active ERK and PKB inhibited staurosporine-induced caspase-3 activation and hepatocyte death. PI3K inhibitor (LY294002) and ERK inhibitor (PD98059) significantly reversed the protective effects of Bcl-x(L) on staurosporine-induced hepatocyte death. Our data suggest that Bcl-x(L) prevents staurosporine-induced hepatocyte apoptosis by modulating protein kinase B and p44/42 mitogen-activated protein kinase activity and disrupts mitochondria death signaling.
Wang
Yinna
Y
Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
Zhang
Baochun
B
Peng
Ximei
X
Perpetua
Michele
M
Harbrecht
Brian G
BG
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019311:Staurosporine / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
D051028:bcl-2-Associated X Protein; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D053148:Caspase 3; D053453:Caspase 9; D019311:Staurosporine