系膜细胞来源的IL-13对系膜细胞促炎性细胞因子基因表达的调控作用

Mesangial Cell-Derived Interleukin-13 Inhibits Cytokines Synthesis by Human Mesangial Cells

摘要:

目的：探讨脂多糖(LPS)对体外培养的人肾小球系膜细胞(HMC)表达IL-13的调节作用及IL-13对HMC促炎性细胞因子、趋化因子和促纤维化因子基因表达的影响，以探讨IL-13对肾小球疾病状态下系膜细胞炎症反应的抑制作用。方法：HMC分为实验组和对照组，实验组予以不同浓度的LPS(1 μg/ml，10 μg/ml，100 μg/ml)刺激或用不同浓度的IL-13(1 ng/ml, 10 ng/ml, 100 ng/ml)预处理。应用RT-PCR和ELISA检测系膜细胞IL-13 mRNA 和蛋白表达；应用核酸酶保护法检测系膜细胞TNF-α，IL-1α，IL-1β，MCP-1，IL-8和TGF-β1 mRNA表达。结果：①未予任何刺激的对照组，系膜细胞不表达IL-13 mRNA和蛋白；LPS可呈剂量依赖性的方式促进系膜细胞IL-13 mRNA的表达和蛋白分泌。②正常培养状态下，系膜细胞可组成型表达TNFα，IL-1β，IL8和TGF-β1，而不表达IL-1α和MCP-1 mRNA；LPS刺激后上述炎症因子表达显著上调；IL-13可呈剂量依赖性地抑制LPS诱导的系膜细胞炎症性细胞因子的基因表达。结论：IL-13是系膜细胞的自分泌因子；IL-13可抑制LPS诱导的系膜细胞促炎性细胞因子、趋化因子和促纤维化因子的表达，提示自分泌和旁分泌的IL-13对于肾小球疾病状态下肾脏系膜细胞的炎症反应具有抑制作用。

Abstract:

OBJECTIVE: To investigate the synthesis of IL 13 in cultured human mesangial cells (HMC) following LPS activation and the inhibitory effect of IL 13 on the pro inflammatory cytokines, chemokines, and pro fibrogentic cytokine expression by HMC. METHODS: The expression of IL 13 mRNA and production of IL 13 protein were determined using the semiquantitative reverse transcription PCR technique and ELISA respectively. TNF α, IL 1α, IL 1β, MCP 1, IL 8, and TGF β1 mRNA expressions were determined by ribonuclease protection assay. RESULTS: ①Basal levels of IL 13 were undetectable and HMC stimulated with LPS produced IL 13 in a dose dependent manner. ②HMC which was incubated in the medium alone did not express IL 1α and MCP 1 mRNA, and constitutive mRNA expression in unstimulated cells was found for TNF α, IL 1β, IL 8, and TGF β1. LPS significantly upregulated TNF α, IL 1α, IL 1β, MCP 1, IL 8, and TGF β1 mRNA expressions. Recombinant human IL 13 inhibited TNF α, IL 1α, IL 1β, MCP 1, IL 8, and TGF β1 mRNA expressions in a dose dependent manner. CONCLUSIONS: LPS can synergistically induce the expression of IL 13 in HMC. IL 13 can inhibit pro inflammatory cytokines, chemokines and profibrogenic cytokine synthesis, which suggests that IL 13 has important regulatory effects on the inflammatory response of HMC.