【摘要】 目的 探讨免疫球蛋白A(IgA)肾病大鼠肾组织及尿液外泌体中白细胞介素6(IL-6)、单核细胞趋化蛋白1(MCP-1)mRNA的表达变化，分析其与肾损伤程度的关系。方法 将40只SD大鼠随机分为对照组（10只）和模型组（30只）。模型组采用脂多糖（LPS）+四氯化碳（CCl4）+牛血清白蛋白（BSA）改良法制备IgA肾病模型。分别于造模第10、12周末各随机选取10只、第14周末选取剩余8只模型组大鼠，收集24 h尿液及血液标本，处死后取肾组织。检测24 h尿蛋白定量（24 h UP）及血清生化指标；苏木精-伊红、PASM、Masson染色及IgA免疫荧光染色观察肾组织病理变化，用肾小球病理积分评估肾病理损伤程度，计算肾小球细胞外基质面积（GECMA）/肾小球面积（GA）；实时荧光定量PCR法检测肾组织及尿液外泌体中IL-6、MCP-1 mRNA表达；免疫组化SP法检测肾组织IL-6、MCP-1蛋白表达；Pearson相关法分析各指标间的相关性。结果 与对照组比较，模型组造模第10周末24 h UP、肾小球病理积分、GECMA/GA及肾组织IL-6、MCP-1蛋白表达高（P均<0.05），而肾组织及尿液外泌体中IL-6、MCP-1 mRNA表达差异无统计学意义（P均>0.05），肾组织发生典型的IgA肾病病理改变。模型组造模第10、12、14周末，24 h UP、总胆固醇、肌酐、肾小球病理积分、GECMA/GA、肾组织及尿液外泌体中IL-6与MCP-1 mRNA表达、肾组织中IL-6与MCP-1蛋白表达均逐渐升高，血清白蛋白水平逐渐降低（P均<0.05）。相关性分析显示，IgA肾病大鼠肾组织及尿液外泌体中IL-6、MCP-1 mRNA表达与肾小球病理积分、GECMA/GA、24 h UP、总胆固醇、肌酐水平呈正相关（P均<0.05），与血清白蛋白水平呈负相关（P均<0.05）。尿液外泌体与肾组织外泌体中IL-6、MCP-1 mRNA表达均呈正相关（P均<0.05）。结论 IgA肾病大鼠肾组织及尿液外泌体中IL-6、MCP-1 mRNA表达上调，与肾损伤程度密切相关。更多还原

【Abstract】 Objective To investigate the expression changes of interleukin-6(IL-6) mRNA and monocyte chemoattractant protein-1(MCP-1) mRNA in the renal tissues and urinary exosomes of rats with immunoglobulin A(IgA) nephropathy and their correlation with the degree of renal injury. Methods Forty male Sprague-Dawley(SD) rats were adaptively fed for one week and then randomly divided into the IgA nephropathy model group(n=30) and control group(n=10). The IgA nephropathy model was established using a combination of lipopolysaccharide(LPS), carbon tetrachloride(CCl4), and bovine serum albumin(BSA). Ten rats were randomly selected from the model group at the 10 th and 12 th week after modeling respectively, and the remaining 8 rats were chosen at the 14 th week. Twenty-four-hour urine and blood samples were collected, and renal tissues were harvested after euthanasia. The 24-hour urinary protein quantification(24 h UP) and serum biochemical indexes were detected. Hematoxylin-eosin(HE), PASM and Masson staining as well as IgA immunofluorescence staining were used to observe the pathological changes of renal tissues. Glomerular pathological scores were adopted to evaluate the degree of renal pathological injury, and the ratio of glomerular extracellular matrix area(GECMA) to glomerular area(GA) was calculated. Quantitative real-time polymerase chain reaction(PCR) was used to determine the mRNA expression levels of IL-6 and MCP-1 in renal tissues and urinary exosomes. Immunohistochemistry was applied to detect the protein expression of IL-6 and MCP-1 in renal tissues. Pearson correlation analysis was used to analyze the correlations among all detected indicators. Results Compared with the control group, the levels of 24 h UP, glomerular pathological score, GECMA/GA, as well as renal IL-6 and MCP-1 protein expression significantly increased in the model group at the 10 th week after modeling(all P<0. 05). No significant differences were found in IL-6 or MCP-1 mRNA expression in renal tissues and urinary exosomes between the two groups(all P>0. 05), and typical pathological changes of IgA nephropathy were observed in renal tissues. From the 10 th week to the 14 th week after modeling in the model group, 24 h UP, total cholesterol, serum creatinine, glomerular pathological score, GECMA/GA, mRNA expression of IL-6 and MCP-1 in renal tissues and urinary exosomes, and renal IL-6 and MCP-1 protein expression were gradually elevated, while serum albumin level gradually decreased(all P<0. 05). Correlation analysis showed that the mRNA expression of IL-6 and MCP-1 in the renal tissues and urinary exosomes of IgA nephropathy rats were positively correlated with glomerular pathological score, GECMA/GA, 24 h UP, total cholesterol and serum creatinine(all P<0. 05), and negatively correlated with serum albumin level(all P<0. 05). Additionally, positive correlations were observed in IL-6 and MCP-1 mRNA expression between urinary exosomes and renal tissue exosomes(all P<0. 05). Conclusion The mRNA expression levels of IL-6 and MCP-1 are up-regulated in renal tissue exosomes and urinary exosomes of IgA nephropathy rats, which are closely associated with the severity of renal injury.更多还原