JAZF1基因调节棕榈酸诱导肝细胞促炎因子表达的作用

Effects of JAZF1 overexpression on proinflammatory cytoldnes in hepatocytes induced by palmitic acid

目的探讨JAZF1过表达对棕榈酸诱导肝细胞促炎因子肿瘤坏死因子（TNF）α、单核细胞趋化蛋白-1（MCP-1）及白细胞介素（IL）-8表达的影响。方法采用棕榈酸作用于肝细胞以构建肝细胞脂肪变性模型，并行油红O染色；将Ad—JAZF1转染入脂肪变性的肝细胞模型中，用RT-pCR法检测转染前后肝细胞JAZF1、TNFα、MCP-1及IL-8mRNA表达，Westem blot法检测JAZF1蛋白表达水平，酶联免疫吸附法检测上述促炎因子的分泌情况。对数据的比较，组内采用配对t检验；组问采用方差分析，进一步两两比较采用LSD法。结果与对照组相比，不同浓度（0、0．125、0．25、0．5、1mmol／L）棕榈酸诱导肝细胞促炎因子TNFα、MCP-1及IL-8mRNA的表达，其相对表达量随着浓度升高呈逐渐升高趋势（P〈0．01），但在0．5mmol／L和1mmol／L浓度组间，差异没有统计学意义。以0．25mmol／L棕榈酸作用于肝细胞0、6、12、24、48h，促炎因子TNFα、MCP-1及IL-8mRNA的相对表达水平随时间延长逐渐升高，在12h达高峰，随后逐渐下降，呈时间依赖性，且各时间组组间差异均有统计学意义（FTNFα=26．51，FMCP-1=57．20，FIL-8=353．85，P值均〈0．01）。与Ad-GFP空载体组相比，Ad—JAZFl转染组肝细胞JAZF1 mRNA和蛋白质的相对表达水平明显增高。JAZF1过表达可以抑制肝细胞中由棕榈酸诱导的TNFα、MCP-1及IL-8mRNA的表达，使其相对表达量分别降低89．69％、77．68％及83．21％护〈0．01），同时TNFα、MCP-1及IL-8相对分泌量也分别减少37％、37％及41％（P〈0．01）。结论棕榈酸能促进肝细胞促炎因子mRNA的表达；JAZF1基因过表达能够抑制棕榈酸诱导的肝细胞促炎因子的表达及释放。

Objective To investigate the effects of JAZF1 overexpression on the pro-inflammatory cytokines in hepatic steatosis. Methods The model of hepatic steatosis was established by incubating hepatocytes with palmitic acid （PA） at 0, 0.125, 0.25, 0.5 and 1 mM dose and for 0, 6, 12, 24 and 48 hours, after which recombinant adenovirus expressing JAZF 1 （Ad-JAZF 1） was introduced to up-regulate expression. Triglyceride level was measured by GOD. Cell viability was detected by CCK-8. The mRNA and protein expression of TNF-α, MCP-1, IL-8 and JAZF1 was examined by RT-PCR, ELISA, and western blotting. Results The PA-treated hepatocytes showed dose-dependent significant increases in TNF-α, MCP-1 and IL-8 mRNA expression for doses up to 0.25 mM; there were no significant increases for the highest doses of 0.5 and 1 raM. The 0.25 mM PA-treated hepatocytes showed time-dependent significant increases in TNF-α, MCP-1 and IL-8 mRNA expressions （FTNF-α = 26.51, FMCP-1 = 57.20, FIL-8 = 353.85, P 〈 0.01）, with the maximum level reached at 12 h and followed by a gradual decrease with longer treatment times. JAZF1 mRNA and protein expression was markedly increased in hepatocytes infected with Ad-JAZF1 （P 〈 0.01）. However, the AP-treated hepatocytes with JAZF1 overexpression showed down-regulation of TNF-α, MCP- 1 and IL-8 mRNA expression （decreased by 89.69%, 77.68%, and 83.21%, respectively） and secretion （37%, 37% and 41%, respectively, P 〈 0.01）. Conclusion Stimulation ofhepatocytes by the PA fatty acid in vitro promotes mRNA expression of TNF-α, MCP-1 and IL-8, but overexpression of JAZF1 inhibits the PA- induced expression and secretion of these factors.