中文摘要：

探讨Kruppel样因子4（KLF4）对内毒素所致白介素（IL-6）的基因表达以及释放的影响,并对其调控机制做了初步研究.使用RT-PCR和Westernblot检测KLF4mRNA和蛋白质的表达.采用KLF4过表达的RAW264.7巨噬细胞株或反义寡核苷酸技术抑制内源性KLF4的表达,用RT-PCR和ELISA检测内毒素（LPS）刺激后IL-6mRNA和蛋白质的表达.采用荧光素酶报告基因检测RAW264.7细胞中KLF4过表达对IL-6基因启动子报告基因转录活性的影响.使用EMSA法检测细胞中KLF4与IL-6基因启动子区KLF4元件的结合.结果表明：LPS可以诱导RAW264.7巨噬细胞KLF4的表达以及IL-6蛋白表达.KLF4过表达明显抑制IL-6的mRNA和蛋白质的表达,而KLF4缺失使这种作用消失.荧光素酶报告基因的结果显示,KLF4可以抑制LPS所致的IL-6基因启动子的转录活性.EMSA显示KLF4不能与IL-6启动子区的KLF4结合元件直接结合.结果表明,LPS可以促进RAW264.7小鼠巨噬细胞KLF4的表达和IL-6的释放.KLF4能抑制LPS诱导的IL-6表达和释放,其机制是抑制IL-6启动子的转录活性，但KLF4的抑制作用不是通过直接与IL-6基因的启动子区相结合而实现的．

英文摘要：

In order to explore the role of Krupperl-like factor 4 （KLF4） in regulating the expression of IL-6 induced by lipopolysaccharide （LPS）. mRNA and protein levels of KLF4 in various periods were determined by RT-PCR and Western blot. A full-length cDNA or antisense oligonucleotides of KLF4 was transfected into RAW264.7 macrophages. The expression and release of IL-6 were analyzed by RT-PCR and ELISA. The transcription and DNA binding activities of KLF4 to the IL-6 promoter were detected by the luciferase reporter and EMSA. The results showed that treatment of RAW264.7 macrophages with LPS resulted in increase in KLF4 and IL-6 protein levels; KLF4 overexpression decreased the expression and release of IL-6, while KLF4 inhibition increased the expression of IL-6. The results from luciferase reporter gene assay demonstrated that KLF4 could inhibit the transcriptional activity of IL-6 gene. The results from EMSA demonstrated that KLF4 could not bind to the KLF4 binding sites on the promoter of IL-6 gene. These data suggested that LPS can stimulated the expression of KLF4 and release of IL-6 in RAW264.7 macrophages; KLF4 can inhibited the release of IL-6 in LPS-stimulated RAW264.7 macrophages; KLF4 can inhibited the transcription activity of IL-6 promoter in RAW264.7 macrophages; this effect of KLF4 is not through binding the IL-6 promoter directly.