雌激素对人肝癌HepG2细胞脂肪变性的作用及AQP7表达的影响

Effect of estrogen on steatosis and expression of AQP7 in HepG2 cells

目的探讨雌激素对人肝癌Hep G2细胞脂肪变性的作用及水通道蛋白7(AQP7)表达的影响。方法将培养后的人肝癌HepG2细胞分为HepG2细胞组、脂肪变模型组、雌激素低剂量组、雌激素高剂量组;其中脂肪变模型组及雌激素低、高剂量组使用2.0m M油酸溶液200μl处理,而雌激素低、高剂量组分别加入500μl浓度为40.0、80.0μg/ml的雌激素,HepG2细胞组不作任何处理;4组细胞均继续培养72h。采用噻唑蓝(MTT)法测定细胞存活率,油红O溶液染色法测定脂滴面积比,贝克曼AU-480全自动生化仪测定TG水平,RT-PCR、Western blot法分别测定HepG2细胞AQP7 mRNA及蛋白相对表达量。结果与HepG2细胞组比较,脂肪变模型组细胞存活率降低(P<0.05),脂滴面积比、TG水平均升高(均P<0.05);与脂肪变模型组比较,雌激素低、高剂量组细胞存活率均升高(均P<0.05),脂滴面积比、TG水平均降低(均P<0.05);与雌激素低剂量组比较,雌激素高剂量组细胞存活率升高(P<0.05),脂滴面积比、TG水平均降低(均P<0.05)。与HepG2细胞组比较,脂肪变模型组AQP7 mRNA及蛋白相对表达量均降低(均P<0.05);与脂肪变模型组比较,雌激素低、高剂量组AQP7 mRNA及蛋白相对表达量均升高(均P<0.05);与雌激素低剂量组比较,雌激素高剂量组AQP7 mRNA及蛋白相对表达量均升高(均P<0.05)。HepG2细胞AQP7 mRNA及蛋白相对表达量与脂滴面积比、TG水平均呈负相关(均P<0.05)。结论雌激素能抑制油酸诱导的HepG2细胞脂肪变性,其机制可能与雌激素能上调AQP7表达有关。

Objective To investigate the effect of estrogen on steatosis and expression of AQP7 in HepG2 cells.Methods Steatosis cell model was induced by treatment of 2.0 m M oleic acid(OA) in human hepatocellular HepG2 cells. And the steatosis HepG2 cells were treated with 40.0μg/ml and 80.0μg/ml estrogen in low estrogen group and high estrogen group,respectively;no estrogen was added in steatosis model group and no OA treatment was given in control group. After cultured for 72 h, the viability of HepG2 cells was measured by MTT, lipid droplet area was measured by oil red O staining, TG level of HepG2 cells was measured by Beckman AU-480 automatic biochemical analyzer, and the expression of AQP7 mRNA and protein in HepG2 cells were measured by RT-PCR and Western blot, respectively. Results Compared with the control group, the cell survival rate of the steatosis model group was decreased(P<0.05), the lipid droplet area ratio and the TG level were increased(both P<0.05). Compared with the steatosis model group, the survival rate of the cells in estrogen low and high dose groups was increased(P<0.05), and the ratio of lipid droplets and TG was lower(P<0.05). Compared with the low-dose estrogen group, the survival rate of high-dose estrogen group was increased(P<0.05), the lipid droplet area ratio and the TG level were decreased(both P<0.05). Compared with control group, the relative expression of AQP7 mRNA and protein in the steatosis model group decreased(P<0.05). Compared with the steatosis model group, the relative expression of AQP7 mRNA and protein in the low and high estrogen groups increased(P<0.05). Compared with the low-dose estrogen group, the relative expression of AQP7 mRNA and protein in the high-dose estrogen group increased(P<0.05). The relative expression of AQP7 mRNA and protein in HepG2 cells was negatively correlated with lipid droplet area and TG level(P<0.05). Conclusion Estrogen can inhibit OA-induced steatosis in HepG2 cells, which may be related to the upregulation of AQP7 expression.