CC类趋化因子受体2、Th1/Th2细胞在IgA肾病大鼠肾间质纤维化中的表达及意义

Expression of C-C Motif Chemokine Receptor 2 and Th1/Th2 Cells in Renal Interstitial Fibrosis of Rats with IgA Nephropathy and Its Significance

目的检测IgA肾病大鼠肾间质纤维化中CC类趋化因子受体2(C-C motif chemokine receptor 2,CCR2)的表达和辅助性T细胞1/2(helper T cell 1/2,Th1/Th2)的含量,并观察其在肾脏纤维化中的作用。方法40只SD雄性大鼠,随机分为模型组和对照组,每组20只。采用脂多糖+改良牛血清白蛋白+四氯化碳法构建免疫球蛋白A(IgA)肾病模型。观察大鼠肾组织病理改变和IgA沉淀,计算胶原纤维占肾组织百分比,采用Katafuchi评分标准评估肾小管间质损伤程度。蛋白质印迹测定肾组织CCR2水平。双抗体夹心酶联免疫吸附法测定血清白细胞介素-4(IL-4)和干扰素-γ(IFN-γ)水平。流式细胞术检测Th1/Th2细胞比例。结果模型组大鼠肾组织胶原纤维面积百分比和Katafuchi评分显著高于对照组(P<0.05);模型组大鼠肾组织CCR2、血清IL-4水平、Th2细胞含量及IL-4/IFN-γ比值显著高于对照组,血清IFN-γ水平、Th1细胞含量显著低于对照组(P<0.05);CCR2和IL-4水平及IL-4/IFN-γ比值与胶原纤维面积百分比、Katafuchi评分呈正相关(P<0.05);IFN-γ水平与胶原纤维面积百分比、Katafuchi评分呈负相关(P<0.05)。结论CCR2和Th1/Th2失衡参与IgA肾病大鼠肾间质纤维化发生和发展,拮抗CCR2和调节Th1/Th2平衡有可能减轻IgA肾病大鼠肾脏纤维化改变。

Objective To investigate the expression of C-C motif chemokine receptor 2(CCR2)and the numbers of helper T cell 1/2(Th1/Th2)in renal interstitial fibrosis of rats with IgA nephropathy and their significance.Methods A total of 40 male SD rats were randomly divided into 2 groups,each group included 20 rats.Immunoglobulin A(IgA)nephropathy in rats was induced by using a combined treatment of lipopolysaccharide(LPS),modified bovine serum albumin(BSA),and carbon tetrachloride(CCl4).The pathological changes and IgA deposition were observed,the percentage of collagen fibers in renal tissues was calculated,and the Katafuchi score was used to evaluate the degree of tubulointerstitial injury.Western blotting was used to detect the expression level of CCR2 in renal tissues.Serum levels of interleukin-4(IL-4)and interferon-γ(IFN-γ)were measured by double-antibody sandwich enzyme-linked immunosorbent assay.Flow cytometry was used to measure the proportion of Th1/Th2 cells.Results The percentage of collagen fiber area and the Katafuchi score in the model group were significantly higher than those in the control group(P<0.05).The expression level of CCR2 in renal tissues,the serum level of IL-4,the number of Th2 cells and the ratio of IL-4/IFN-γin the model group were significantly higher than those in the control group,while the serum level of IFN-γand the number of Th1 cells were significantly lower than those in the control group(P<0.05).The levels of CCR2 and IL-4 and the ratio of IL-4/IFN-γwere positively correlated with the collagen fiber area percentage and the Katafuchi score(P<0.05),while the level of IFN-γwas negatively correlated with collagen fiber area percentage and the Katafuchi score(P<0.05).Conclusion The abnormal expression of CCR2 and the Th1/Th2 Imbalance are involved in the occurrence and development of renal interstitial fibrosis in IgA nephropathy rats,meanwhile,antagonizing CCR2 and regulating Th1/Th2 balance may reduce the changes of renal fibrosis in IgA nephropathy rats.