高糖环境对肾小球足细胞及TNFR1的影响

Effects of high glucose environment on glomerular podocytes and TNFR1

目的:探究高糖环境下小鼠肾小球足细胞及炎症因子TNFR1的改变,期望为糖尿病肾病(DN)的防治提供新的思路。方法:将离体培养的小鼠肾小球足细胞分别设为正常对照组(D-葡萄糖5.5 mmol/L)、高渗组(D-葡萄糖5.5 mmol/L+甘露醇39.5 mmol/L)、高糖组(D-葡萄糖45 mmol/L)。刺激48 h后,用western blotting检测高渗组、高糖组足细胞胰岛素信号通路的关键蛋白、纤维化标志蛋白、炎症水平的变化,以及炎症因子TNFR1的表达情况;刺激72 h后,观察高糖组足细胞形态及细胞核的变化。结果:刺激48 h后,pIRS-1^(Ser307)在高渗组和高糖组表达均高于正常组,pAKT^(Ser473)在高糖组表达低于正常组,足细胞胰岛素抵抗水平上升; CollagenⅠ、Fibronectin及IL1β在高渗组和高糖组表达均高于正常组,足细胞纤维化水平及炎症水平上升;此外,炎症因子TNFR1在高渗组和高糖组表达也高于正常组。刺激延长至72 h,与正常对照组比较,高糖组足细胞形态发生改变并开始出现凋亡。结论:高糖可影响足细胞的形态及生存,提高足细胞炎症水平。甘露醇和高糖均促进炎症因子TNFR1的表达,推测DN伴随的高渗、高糖均可影响TNFR1在足细胞的表达。TNFR1可能成为DN防治的新靶点。

Objective: To investigate the changes of podocytes and TNFR1 in mice under high glucose environment for new direction to the prevention and treatment of diabetic nephropathy(DN). Methods :MPC5 podocytes were incubated with in vitro technique,and allocated to control group(D-glucose dose in 5.5 mmol/L),hyperosmotic group(D-glucose in dose of 5.5 mmol/L+mannitol in dose of 39.5 mmol/L) and high glucose group(D-glucose dose in 45 mmol/L).Western blot was performed to detect the changes of insulin signaling pathway,fibrosis and inflammation levels,TNFR1 expression in the podocytes 48 h following stimulation.Morphology and nucleus changes of podocytes were observed at 72 h after glucose stimulation. Results :After stimulating podocytes for 48 hours,pIRS-1 Ser307 expression was higher,yet pAKT Ser473 expression was lower in hyperosmotic and high glucose groups than in the control group,and insulin resistance level was increased in the podocytes.CollagenⅠ,Fibronectin and IL1β expression was higher in hyperosmotic and high glucose group than in the control group,with increased fibrosis and inflammation levels in the podocytes.Higher expression of inflammatory factor TNFR1 was also observed in hyperosmotic and high glucose groups.After stimulating the podocytes for 72 hours,podocyte morphology changed and apoptosis occurred in the high glucose group. Conclusion :High glucose affects the morphology and survival,and increases inflammation level in the podocytes.Both mannitol and high glucose may promote the expression of inflammatory factor TNFR1.DN associated with hyperosmolar and high glucose level can be speculated to regulate the expression of TNFR1 in podocytes,suggesting that TNFR1 may be a new target for the prevention and treatment of DN.