Glycogen synthase kinase-3β regulates etoposide-induced apoptosis via Bcl-2 mediated caspase-3 activation in C3H10T1/2 cells
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Glycogen synthase kinase-3β (GSK3β) controls the survival of osteoblasts during bone development through Wnt canonical signaling. GSK3β 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 GSK3β activation in C3H10T1/2 cells, a mouse mesenchymal cell line. Etoposide led to the time-dependent activation of GSK3β and caspase-3, which resulted in PARP cleavage. LiCl (a specific inhibitor) and siRNA (gene knock-down) of GSK3β 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 GSK3β, which leads to caspase-3 activation via decrease in Bcl-2 expression.
KeywordsC3H10T1/2 Apoptosis Etoposide Glycogen synthase kinase-3β (GSK3β) Bcl-2
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