乙型肝炎病毒编码X蛋白降低大鼠肝脏卵圆细胞对β 型转化生长因子1增殖抑制效应敏感度的研究

The hyposensitization of oval cell to antiproliferative effect of transforming growth factor β1 byhepatitis B virus X gene

目的研究大鼠肝脏卵圆细胞中乙型肝炎病毒编码X蛋白（HBX）对B型转化生长因子（TGFl3）1增殖抑制效应的影响。方法转染HBX基因的大鼠肝脏卵圆细胞系HBX．EGFP．LE／6作为实验组，大鼠肝脏卵圆细胞系LE／6和转染绿色荧光标记空载体的大鼠肝脏卵圆细胞系EGFP．LE／6作为空白对照和阴性对照组。采用real—timePCR和Westernblot分别检测各组TGFl3受体2的mRNA及蛋白表达水平。各组细胞在体外培养中加入5μ/L外源性TGF[M，采用MTT增殖实验比较各组细胞对外源性TGFβ 1细胞增殖抑制效应的不同反应性。结果实验组TGFl3受体2的mRNA和蛋白表达水平较两个对照组均明显下调（P〈0．05）。MTT增殖实验结果表明HBX在体外影响TGFβ1对卵圆细胞的增殖抑制作用，稳定转染HBX的卵圆细胞株HBX—EGFP—LE／6对TGFβI的增殖抑制效应的反应性为18．1％±1．5％，低于其余两组的42．2％±2．8％和41．9％±5．0％（P〈0．05）。结论HBX在肝脏卵圆细胞中的表达影响TGFβ受体2在卵圆细胞中的转录活性和蛋白合成，并且降低肝脏卵圆细胞对TGFβ1增殖抑制效应的敏感度。

[ Abstract] Objective To determine whether hepatitis B virus X （HBX） protein expression affect the oval cells＇ response to anti-proliferative effect of transforming growth factor β1 （ TGFβ1 ） in oval cells. Methods Real-time PCR, Western blot analysis were performed to detect the expression of TGFβR lI in HBX-transfected oval cells named HBX-EGFP-LE/6, and EGFP-LE/6, LE/6 control cells. In addition, exogenous TGFβ1 was added into all three oval cell lines, MTI assay was preformed to clarify different responses to the anti-proliferative effect of TGFβ1. Results The TGFI3R II mRNA levels in LE/6 and EGFP-LE/6 cells were （ 10. 2 ± 1.8 ） and （ 8.8 ± 0. 9 ） folds of those in HBX-EGFP-LE/6 cells, the difference was significant （P 〈 0. 05 ）. HBX protein expression also reduced the protein levels of TGFβR lI in HBX-EGFP-LE/6 oval cells, compared to the control cells. The MTT results exhibited that, after TGFIS1 addition, proliferative inhibition rate in the HBX-EGFP-LE/6 cells was 18.1% ± 1.5% while those in control cells were 42. 2% ± 2. 8% and 41.9% ± 5.0% , the difference was significant （ P 〈 0. O1 ）. Conclusion HBX protein expression affects TGFβR I1 transcriptional activity and protein synthesis, and insensitive oval cells to anti-proliferative effect of TGFβ1.