PI3K/Akt信号通路与肝星状细胞活化的关系及其在放射性肝纤维化中的作用

Relationship of PI3K/Akt signaling pathway and the activation of hepatic stellate cells and its role in radiation-induced hepatic fibrosis

目的 探讨磷脂酰肌醇3激酶-蛋白激酶B（PI3 K/Akt）信号通路与肝星状细胞（HSC）活化的关系及其在放射性肝纤维化中的作用.方法 6MVX射线照射,联合PI3K/Akt信号通路特异性抑制剂处理HSC,分为空白对照组、抑制剂组、10 Gy照射组、10 Gy＋抑制剂组、20 Gy照射组和20 Gy＋抑制剂组.检测各组的细胞凋亡率、细胞上清液转化生长因子β1（TGF-β1）浓度、平滑肌肌动蛋白（α-SMA）的mRNA表达量和磷酸化蛋白激酶B（p-Akt）的表达量.结果 与空白对照组相比,10和20 Gy照射组细胞的凋亡率随照射剂量的增加而增加（=8.43、11.63,P＜0.05）;与10和20 Gy照射组比较,分别加抑制剂后细胞的凋亡率降低（t=8.09、4.88,P＜0.05）.与10 Gy照射组比较,20 Gy照射组TGF-β1、α-SMA、p-Akt的量增加（t=6.91、7.80、9.28,P＜0.05）,10 Gy＋抑制剂组TGF-β1、α-SMA、p-Akt的量降低（t=6.17、15.11、10.34,P＜0.05）.与20 Gy照射组比较,20 Gy＋抑制剂组TGF-β1、α-SMA、p-Akt的量同样降低（t=10.04、6.85、23.84,P＜0.05）.结论 X射线通过激活PI3K/Akt信号通路使HSC活化,导致放射性肝纤维化的发生.

Objective To investigate the relationship of PI3K/Akt signaling pathway with the activation of hepatic stellate cells （HSC） and its role in radiation-induced hepatic fibrosis.Methods HSC was treated with 6 MV X-ray irradiation （IR） together with the inhibitor of PI3K/Akt signaling pathway.The cells were divided into inhibitor group,10 Gy IR group,10 Gy ＋ inhibitor group,20 Gy IR group,an 20 Gy ＋ inhibitor group and blank control group.Then cell apoptosis rate was detected,the expression of transforming growth factor β1 （TGF-β1） in cell supernatant and the mRNA expressions of α-smooth muscle actin （α-SMA） and phosphorylation protein kinase B （p-Akt） were measured.Results Compared with the control group,the apoptosis rate of 10 and 20 Gy IR group increased with irradiation dose （t =8.43,11.63,P 〈0.05） but they were reduced by the inhibitor of PI3K/Akt （t =8.09,4.88,P 〈0.05）.The expressions of TGF-β1,α-SMA,and p-Akt also increased with irradiation dose （t =6.91,7.80,9.28,P〈0.05） but they were declined by this inhibitor for both 10 Gy IR （t =6.17,15.11,10.34,P〈0.05） and 20 Gy IR （t =10.04,6.85,23.84,P〈0.05）.Conclusions X-ray irradiation could activate HSC through PI3K/Akt signaling pathway,which may further result in hepatic fibrosis.