摘要
目的 探讨白细胞介素22（IL-22）对糖尿病肾纤维化的作用及机制。方法 将C57 BL/6小鼠分为正常对照组（NC组）、糖尿病肾病对照组（DN组）、重组IL-22（rIL-22）组和IL-22中和抗体（Anti-IL-22）组，糖尿病造模成功8周后，按分组给予200 ng/g rIL-22、Anti-IL-22或等量0.1%牛血清白蛋白（BSA）腹腔注射，每周2次，连续4周。干预结束后，测定血糖、肾功能和24 h尿微量白蛋白/肌酐比值，光镜下观察小鼠肾脏病理学改变和胶原沉积情况，同时对肾组织硬化及纤维化指标进行半定量评定，实时荧光定量PCR分析肾脏组织转化生长因子-β1（TGF-β1）基因转录水平，Western印迹法检测肾脏组织α-平滑肌动蛋白（α-SMA）、E-钙黏蛋白（E-cadherin）和纤连蛋白（FN）表达水平，免疫组化分析肾脏组织胶原纤维Ⅲ（collagen Ⅲ）表达水平。结果 干预4周后，Anti-IL-22组24 h尿微量白蛋白/肌酐比值显著降低（P〈0.05）。光镜下可见糖尿病小鼠肾小管上皮细胞空泡变性、蛋白管型形成和肾小球系膜扩张，rIL-22组上述病变更广泛，而Anti-IL-22组病变程度得以改善，胶原沉积情况与肾小管损伤分数一致。实时荧光定量PCR发现rIL-22组TGF-β1 mRNA显著升高（P〈0.01）。免疫印迹发现rIL-22组肾小管上皮-间充质转分化（EMT）标志物α-SMA显著升高（P〈0.05）和E-cadherin显著下降（P〈0.05），且细胞外基质（ECM）蛋白FN显著升高（P〈0.05）。免疫组化发现rIL-22组collagen Ⅲ显著升高（P〈0.05）。结论 IL-22可能通过介导肾小管上皮细胞TGF-β1的高表达，诱导EMT发生和促进ECM积聚，加速糖尿病肾纤维化。
Objective To investigate the effects of interlukin-22 （IL-22） on diabetic renal fibrosis and its possible mechanisms. Methods C57 BL/6 mice were randomized to normal control group （ NC group）, diabetic nephropathy control group （ DN group）, recombinant interlukin-22 （rIL-22） group, and interlukin-22 antibody （Anti-IL-22） group. 8 weeks after successful establishment of diabetes model, mice were injected intraperitoneally with 200 ng/g rIL-22, Anti-IL-22 or equal 0.1% bovine serum albumin （BSA） twice a week for 4 weeks. After the intervention, blood glucose, kidney function and 24 h urine microalbumin creatinine ratio were measured. Renal pathological changes and collagen deposition were observed under the light microscope, and semiquantitative assessment of renal sclerosis and fibrosis were evaluated at the same time. The mRNA expression of transforming growth factor （TGF）-β1 was determined by realtime PCR. The protein expressions of a-smooth muscle actin （α-SMA）, E-cadherin, and fibronetin （FN） were examined by Western blotting. The protein expressions of collagen m were examined by immunohistoehemical analysis. Results After 4 weeks of intervention, the 24 h urine microalbumin creatinine ratio decreased significantly in the Anti-IL-22 group （ P〈0. 05 ）. Renal tubular epithelial ceils vacuolar degeneration, protein cast formation, and glomerular mesangial expansion were observed under the light microscope. And the lesions were more severe in the rIL-22 group, whereas improved in the Anti-IL-22 group. Meanwhile, the collagen deposition was in accordance with the tubular injury score. Moreover, TGF-β1 gene expression increased significantly in the rIL-22 group （P〈0.01）. α-SMA and E-cadherin, epithelial-mesenchymal transition （EMT） markers, increased or decreased significantly in the rIL-22 group respectively （ P〈0.05 ）. FN and collagen lll, extracellular matrix （ECM） proteins, increased significantly in the rIL-22 group as well （P 〈 0.05）. Conclusions IL-22 may induce renal tubular epithelial cells TGF-β1 high expression. As a consequence, this contributes to EMT occurance and ECM accumulation, eventually accelerating the progression of diabetic renal fibrosis.
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2017年第9期769-775,共7页
Chinese Journal of Endocrinology and Metabolism
基金
湖北省自然科学基金（2012FFB06807）
作者简介
通信作者：赵林双．Email：zls7111@aliyun．com
