中文摘要：

目的研究IL-22对ox-LDL诱导的CRL-1730细胞（人脐静脉内皮细胞）凋亡的影响及其机制。方法 100μg/ml ox-LDL刺激CRL-1730细胞,不同时间点经实时荧光定量RT-PCR检测CRL-1730细胞中IL-22受体R1（IL-22R1）mRNA的表达状况。然后在ox-LDL诱导的CRL-1730细胞凋亡模型中加入20 ng/ml外源性IL-22,通过AnnexinⅤ-PI凋亡试剂盒检测其对细胞凋亡的影响,经实时荧光定量反转录PCR检测Bcl-2、Bcl-xl、Bcl-w、caspase 3及STAT3mRNA的表达,采用免疫印迹法分析STAT3磷酸化和Bcl-2蛋白的水平。结果 IL-22R1 mRNA在ox-LDL刺激后表达明显增高（P〈0.05）,且于12 h达峰值（P〈0.01）;加入IL-22可明显抑制ox-LDL刺激诱导的内皮细胞凋亡（P〈0.01）,促进抗凋亡基因Bcl-2、Bcl-xl和Bcl-w表达,而降低caspase 3 mRNA表达（P〈0.01）。此外,IL-22作用1～2 h STAT3发生磷酸化,4 h后Bcl-2蛋白表达升高（P〈0.01）。结论 IL-22可抑制ox-LDL诱导的CRL-1730细胞凋亡,这可能与其促使STAT3磷酸化,上调抗凋亡分子Bcl-2、Bcl-xl和Bcl-w的表达,抑制促凋亡分子caspase 3的表达有关。

英文摘要：

Objective To investigate the effect of interleukin-22（IL-22） on apoptosis of CRL-1730 cells（human umbilical vein endothelial cell line） induced by ox-LDL and the possible mechanism.Methods Expression of IL-22 receptor R1（IL-22R1） mRNA in CRL-1730 cells stimulated with ox-LDL（100 μg/ml） was detected by fluorescence quantitative RT-PCR.Flow cytometry was applied to examine the effect of exogenous IL-22（20 ng/ml） on the ox-LDL-induced apoptosis of CRL-1730 cells.The expression of Bcl-2,Bcl-xl,Bcl-w,caspase 3,and STAT3 mRNA in CRL-1730 cells treated or untreated with IL-22 and ox-LDL were measured by fluorescence quantitative RT-PCR;the phosphorylation status of STAT3 and the Bcl-2 protein level were examined by Western blotting analysis.Results The expression of IL-22R1 mRNA increased in a time-dependent manner（P〈0.05） and peaked at 12 h after ox-LDL stimulation.Treatment with IL-22 significantly inhibited the apoptosis of CRL-1730 cells induced by ox-LDL（P〈0.01）,increased the expression of anti-apoptosis genes Bcl-2,Bcl-xl,and Bcl-w,and decreased expression of caspase 3 mRNA（P〈0.01）.STAT3 phosphorylation occurred 1-2 h after IL-22 treatment and Bcl-2 protein expression increased 4 h after IL-22 treatment in ox-LDL stimulated CRL-1730 cells.Conclusion IL-22 can inhibit the pro-apoptosis effect of ox-LDL in the CRL-1730 cells,which might be associated with the increased expression of Bcl-2,Bcl-xl,and Bcl-w mRNA,decreased expression of caspase 3,and induced STAT3 phosphorylation.