细胞因子信号转导抑制物-3及固醇调节元件结合蛋白-1c通路在脂肪变性HepG2／HepG2．2．15细胞中的变化

Changes of suppressors of cytokine signaling-3 and steroi regulatory element binding proteins-lc pathway in steatosis HepG2/HepG2. 2.15 cells

目的探讨HepG2和HepG2.2.15细胞脂肪变性对细胞因子信号转导抑制物-3（supressors of cytokine signaling-3，SOCS-3）、固醇调节元件结合蛋白-1c（sterol regulatory element binding proteins，SREBP-1c） mRNA和蛋白表达的影响。方法油酸诱导HepG2和HepG2.2.15细胞脂肪变性，成功构建脂变的细胞模型，分为HepG2对照组、HepG2.2.15对照组、HepG2脂变组和HepG2.2.15脂变组。实时定量PCR法检测细胞中SOCS-3及SREBP-1c mRNA的表达情况，蛋白质印迹法测定细胞中SOCS-3及SREBP-1c蛋白的表达变化。统计学处理采用单因素方差分析和Tukey法。 结果SOCS-3 mRNA表达水平，HepG2.2.15对照组显著低于HepG2对照组，HepG2脂变组显著低于HepG2对照组，差异均有统计学意义（均P〈0.01）；HepG2.2.15脂变组较HepG2.2.15对照组也降低，但差异无统计学意义（P＝0.173）；细胞与脂变有交互作用（F＝25.547，P〈0.01）。SREBP-1c mRNA水平，HepG2.2.15对照组表达低于HepG2对照组，HepG2.2.15脂变组表达明显高于HepG2.2.15对照组，差异均有统计学意义（均P〈0.01）；HepG2脂变组与HepG2对照组差异无统计学意义（P＝1.000）；细胞与脂变有交互作用（F＝5.04，P〈0.05）。蛋白质印迹法检测结果显示，两组细胞脂变48、72 h后SOCS-3和SREBP-1c蛋白水平显著高于非脂变细胞。结论两组细胞脂变后SOCS-3和SREBP-1c蛋白的表达出现上调。细胞与脂变之间存在交互作用，HBV基因可以抑制脂变细胞SOCS-3 mRNA的表达，促进SREBP-1c mRNA的表达。

ObjectiveTo investigate the effects of HepG2 and HepG2.2.15 cells steatosis on the mRNA and protein expressions of suppressors of cytokine signaling-3（SOCS-3） and sterol regulatory element binding proteins （SREBP-1c）. MethodsThe cell model of chronic hepatitis B （CHB） combined with nonalcoholic fatty liver disease （NAFLD） was successfully constructed using an oleic acid-induced HepG2 and HepG2.2.15 cells steatosis. Cells were divided into HepG2 cell control group （HepG2 cell control group）, HepG2.2.15 cell control group （HepG2.2.15 cell control group）, HepG2 cell steatosis group （HepG2 cell steatosis group） and HepG2.2.15 cell steatosis group （HepG2.2.15 cell steatosis group）. The expression levels of SOCS-3 and SREBP-1c mRNA were detected by real-time quantitative polymerase chain reaction （PCR）. Changes in protein expressions of SOCS-3 and SREBP-1c were measured by western blot. ResultsSOCS-3 mRNA expression level in HepG2.2.15 cell control group was significantly lower than that in HepG2 cell control group （P〈0.01）. The level in HepG2 cell steatosis group was also significantly lower than that in HepG2 cell control group （P〈0.01）. However, the level of SOCS-3 mRNA in HepG2.2.15 cell steatosis group was lower than HepG2.2.15 cell control group with no statistical significance （P=0.173）. There was interaction between cells and steatosis （F=25.547, P〈0.01）. The expression of SREBP-1c mRNA in HepG2.2.15 cell control group was significantly lower than that in HepG2 cell control group （P〈0.01）, and was significantly higher in HepG2.2.15 cell steatosis group than that in HepG2.2.15 cell control group （P〈0.01）. There was no significant difference between HepG2 cell steatosis group and HepG2 cell control group （P=1.000）. There was interaction between cells and steatosis （F=5.04, P〈0.05）. Western blot analysis showed that protein levels of SOCS-3 and SREBP-1c in steatosis cells at 48 h and 72 h were significantly higher than those in non-alcoholic steatosis cells. ConclusionsProtein expressions of SOCS-3 and SREBP-1c are up-regulated in both steatosis groups. Factorial analysis shows that there is interaction between cells and steatosis. HBV gene could inhibit SOCS-3 mRNA expression and promote the expression of SREBP-1c mRNA in steatosis cells.