STAT1信号通路在成骨细胞凋亡蛋白表达中的作用

Role of STAT1 signaling pathway in osteoblast apoptosis and effect of blocking the path

目的研究转录活化蛋白1(STAT1)信号通路在成骨细胞凋亡蛋白表达中的作用。方法用细胞计数试剂盒8(CCK-8)法检测不同浓度氟达拉滨对成骨细胞的毒性作用,Western blot和ELISA方法检测在不同时间及地塞米松浓度下,Bcl-2相关X蛋白(BAX)、裂解的caspase-3蛋白(cleaved caspase-3)、STAT1及STAT1的磷酸化蛋白(p-STAT1)的蛋白水平。大鼠成骨细胞设对照组、单纯氟达拉滨组、地塞米松组、地塞米松+氟达拉滨组,ELISA方法检测BAX、STAT1和p-STAT1的蛋白量及分光光度法测cleaved caspase-3的蛋白水平。结果在地塞米松刺激作用下,成骨细胞凋亡相关蛋白及p-STAT1的蛋白水平增高,且具有时间及浓度依赖性。应用氟达拉滨下调p-STAT1水平后,地塞米松+氟达拉滨组凋亡相关蛋白表达较地塞米松组下降(P <0. 05)。结论氟达拉滨可以通过抑制p-STAT1的活性下调cleaved caspase-3等凋亡蛋白水平。

Objective To investigate the role of signal transducer and activator of transcription （STATl） signaling pathway in osteoblast apoptosis, and to study the effect of STAT1 inhibitor （fiudara- bine） 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, dex- amethasone （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-signal 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 apop- tosis-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.