ABSTRACT
Objective To investigate the role of signal transducer and activator of transcription (STAT1) signaling pathway in osteoblast apoptosis,and to study the effect of STAT1 inhibitor (fludarabine) on osteoblast.Methods The viability of the osteoblasts in different concentration of fludarabine was detected by cell counting kit-8 (CCK-8) assay.Osteoblasts were divided into 4 groups:control group,dexamethasone (Dex) group,fludarabine (Flu) group,and Dex + Flu group.Enzyme linked immunosorbent (ELISA) was used for determining the protein expression of Bcl-2 Associated X Protein (BAX),STAT1 and phosphorylation-sigual transducers and activators of transcription 1 (p-STAT1),and cleaved caspase-3 to reflect the apoptosis in all groups.Results Treatment with Dex increased the protein expression of apoptosis-related proteins and p-STAT1 in time-dependent and dose-dependent manner.Exposure of the cells to Flu,which was a selective STAT1 inhibitor,resulted in a decreased the protein levels of apoptosis-related proteins.Conclusions Our results suggest that fludarabine could suppress Dex-induced apoptosis through the inhibition of STATl-mediated up-regulation cleaved caspase-3 expression in osteoblasts.