中文摘要：

目的探讨高糖（HG）能否通过转化生长因子β（TGF—β）途径诱导大鼠肾小球内皮细胞向肌成纤维细胞转分化（EndMT）。方法体外培养大鼠肾小球内皮细胞（GEnC），分为正常对照组（NG，5．5mmol／L）、高糖组（HG，15、30mmol／L）、TGF—B抑制剂组（HG＋LY36，30mmol／L葡萄糖＋10μmol／LLY364947）以及高渗对照组（M，5．5mmol／L葡萄糖＋25．5mmol／L甘露醇）和溶剂对照组（D，5．5mmol／L葡萄糖＋1ml／LDMSO）。采用Western印迹法检测各组细胞内皮细胞标志物claudin5和肌成纤维细胞标志物α-SMA表达变化；实时定量PCR法检测细胞TGF—β1和TGF—β2mRNA表达改变；免疫荧光法观察细胞形态学变化以及血管内皮细胞标志物VE—cadherin和肌成纤维细胞标志物α—SMA的表达。结果与NG组比较，HG组claudin5蛋白的表达量随葡萄糖浓度增加而降低（P〈0．05），α－SMA蛋白表达量随葡萄糖浓度增加而升高（P〈0．05），TGF-β1和TGF—β2mRNA表达均升高（P〈0．05）。与HG组比较，TGF－β抑制剂组claudin5蛋白表达量升高（P〈0．05），α—SMA蛋白表达降低（P〈0．05）。高渗对照组和溶剂对照组改变差异无统计学意义。激光共聚焦免疫荧光结果显示，高糖处理可引起细胞形态由卵圆形向梭形改变，VE－cadherin表达减少，α－SMA表达增加；TGF－β抑制剂组细胞形态无明显改变。与HG组比较，TGF－β抑制剂组VE—cadherin表达增加，α—SMA表达降低（P〈0．05）。结论高糖诱导大鼠肾小球内皮细胞TGF－β表达增加及内皮细胞－肌成纤维细胞转分化。抑制TGF—β可抑制高糖引起的转分化，提示TGF—β参与了高糖引起的肾小球内皮细胞转分化过程。

英文摘要：

Objective To investigate whether high glucose can induce endothelial- mesenchymal transition （EndMT） in glomerular endothelial cells and the role of TGF- 13 in the process. Methods Rat glomerular endothelial cells were divided into five groups： normal glucose （NG, 5.5 mmol/L）, high glucose （HG, 15, 30 mmol/L）, TGF-β inhibition （HG ＋ LY36, 30 mmol/L glucose ＋ 10 μmol/L LY364947）, hyperosmotic control （M, 5.5 mmol/L glucose＋25.5 mmol/L mannitol） and solvent control （D, 5.5 mmol/L glucose＋ 1 ml/L DMSO）. protein quantities of endothelial marker claudin 5 Western blotting was performed to detect relative and mesenchymal marker α- smooth muscle actin （ot-SMA）. TGF-β1 and TGF-β2 mRNA levels were measured by real-time PCR. Vascular endothelial marker VE-cadherin and mesenchymal marker o~-SMA were detected by immunofluorescent stain and observed by confocal microscopy. Results Compared with NG, the expression of claudin5 protein in HG （15 or 30 mmol/L） was up-regulated while expression of α-SMA protein was down-regulated （P 〈 0.05）. Both TGF-β1 and TGF-β2 mRNA levels increased as well （P 〈 0.05）. However, when compared with HG, the claudin 5 levels increased while α- SMA decreased in TGF-β inhibition group. No significant changes were observed in hyperosmotic or solvent control group. Confocal microscopy showed the transformation of cells from a cobblestone-liked shape to a spindle one, and a decreasing expression of VE- cadherin while an increasing α- SMA in HG group （P 〈 0.05）, whereas TGF- β inhibition partly attenuated those changes in both morphological and protein levels. Conclusions High glucose treatment of glomerular endothelial cells results in an increase in the level of TGF- β1 and TGF- β2 mRNA and leads to endothelial- mesenchymal transiton. Inhibition of TGF- β partly prevents this process, indicating that TGF-β plays a crucial role in high-glucose-induced glomerular endothelial-mesenchymal transiton.