title: Glycogen synthase kinase-3beta regulates etoposide-induced apoptosis via Bcl-2 mediated caspase-3 activation in C3H10T1/2 cells.
abstract: Glycogen synthase kinase-3beta (GSK3beta) controls the survival of osteoblasts during bone development through Wnt canonical signaling. GSK3beta is a key factor for osteoblastogenesis, but relatively less is known regarding its role in osteoblast apoptosis. Genotoxic stress induced by etoposide promoted apoptotic signaling by GSK3beta activation in C3H10T1/2 cells, a mouse mesenchymal cell line. Etoposide led to the time-dependent activation of GSK3beta and caspase-3, which resulted in PARP cleavage. LiCl (a specific inhibitor) and siRNA (gene knock-down) of GSK3beta prevented the effects of etoposide on apoptosis. Staurosporine also induced apoptosis in C3H10T1/2 cells, but LiCl could not rescue. Bcl-2 was decreased in the cells by exposure to etoposide. LiCl completely recovered Bcl-2 expression as shown by both the mRNA and the protein expression levels. In conclusion, etoposide-induced apoptosis in C3H10T1/2 cells is mediated by GSK3beta, which leads to caspase-3 activation via decrease in Bcl-2 expression.
authors.affiliation: Department of Endocrinology and Metabolism, Ajou University School of Medicine, San 5 Wonchon-Dong Yeongtong-Gu, Suwon City, Gyeonggi, 443-721, South Korea.
authors.forename: Sun-Il
authors.initials: SI
authors.lastname: Yun
authors.forename: Hyung-Young
authors.initials: HY
authors.lastname: Yoon
authors.forename: Yoon-Sok
authors.initials: YS
authors.lastname: Chung
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism*; D002460:Cell Line; D019610:Cytoprotection / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005047:Etoposide / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D018021:Lithium Chloride / Q000494:pharmacology; D051379:Mice; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D019311:Staurosporine / Q000494:pharmacology
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D005047:Etoposide; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3; D053148:Caspase 3; D018021:Lithium Chloride; D019311:Staurosporine