高糖诱导足细胞发生上皮-间叶细胞转分化

目的 通过观察高糖是否引起小鼠足细胞发生上皮-间叶细胞转分化现象，探讨糖尿病肾小球损伤的可能机制。 方法 以小鼠永生化足细胞株为研究对象，予不同浓度葡萄糖（12.5、25、50 mmol/L）处理该细胞36 h，并设低糖（5.6 mmol/L）和甘露醇（50 mmol/L）处理组为对照组。采用蛋白免疫印迹和间接免疫荧光染色方法检测α平滑肌肌动蛋白 （α-SMA）、迁连蛋白（FN）、CD2相关蛋白（CD2AP）和Wilms’肿瘤1基因（WT-1）蛋白的表达。 结果 低糖（5.6 mmol/L）和甘露醇（50 mmol/L）处理条件下小鼠足细胞表达WT-1、CD2AP，基本不表达α-SMA和FN；而予不同浓度葡萄糖处理36 h后，足细胞中α-SMA和FN表达水平呈剂量依赖性上调（P < 0.05）。间接免疫荧光染色结果也显示，与低糖组相比，高糖组中 α-SMA阳性的足细胞比例显著增加（P < 0.05）。同时，蛋白免疫印迹结果还表明高糖可呈剂量依赖性方式下调WT-1和CD2AP的表达（P < 0.05）。 结论 在高糖条件下，足细胞发生向间叶细胞表型的转分化可能是引起足细胞功能失调，进而引起糖尿病肾小球损伤发生的作用机制之一。

Epithelial -mesenchymal transition induced by high glucose in mice podocyte cell line

Objective To investigate the possible mechanism of glomerular injury in diabetes mellitus by determining whether epithelial-mesenchymal transition (EMT) is caused by high glucose in mice podocytes. Methods Using mice glomerular podocyte cell line as an in vitro system, podocytes were incubated with glucose(12.5 mmol/L, 25 mmol/L, 50 mmol/L) and mannitol (50 mmol/L) for 36 hours. Then the cells were collected and expression of alpha-smooth muscle actin(α-SMA), fibronectin (FN), CD2 associated protein (CD2AP) and Wilms' tumor 1 gene (WT-1) was detected by Western blot and indirect immunofluorescence staining. Results Under low glucose (5.6 mmol/L) and mannitol (50 mmol/L) condition, there were high expression of CD2AP and WT-1, and low expression of α-SMA and FN in mice podocytes. After 36 hours treatment with high glucose (12.5 mmol/L), the expression of α-SMA and FN in podocytes was significantly increased, and the expression of α-SMA and FN was further up-regulated with the increase of glucose dosage (25, 50 mmol/L). The indirect immunofluorescence staining revealed the similar result, and the percentage of positive α-SMA cells was also increased compared with low glucose and mannital group (P<0.05). Meanwhile, Western blot showed that high glucose could down-regulate the expressions of CD2AP and WT-1 in a dose-dependent manner. Conclusion EMT may be a potential pathway leading to podocyte dysfunction and glomerular injury under high glucose conditions.