C肽对高糖下肾足细胞凋亡和肾病蛋白的影响

Effects of C peptide on nephrin and apotosis in podocyte under high glucose

目的探讨C肽对高糖下肾足细胞凋亡和肾病蛋白的影响。方法将肾足细胞分成4组:对照组(5 mmol/L葡萄糖)、高糖组(25 mmol/L葡萄糖,下同)、C肽组(高糖+C肽)、百日咳毒素(PTX)组(高糖+C肽+PTX),干预24 h后,Western blot检测磷脂酰肌醇3激酶(PI3K)、蛋白激酶B(Akt)和m TOR蛋白,免疫荧光法检测肾病蛋白,TUNEL一步法检测足细胞凋亡。结果 5 nmol/L C肽即能显著抑制高糖下足细胞m TOR的表达(P<0.01)。与对照组相比,高糖组PI3K、Akt和m TOR表达显著升高(P<0.05),肾病蛋白表达显著下降(P<0.01),足细胞凋亡显著增加(P<0.01);与高糖组相比,C肽能逆转高糖所致的上述变化(P<0.01),而PTX能消除或减弱C肽的上述逆转作用(P<0.05)。结论C肽可抑制高糖激活的足细胞PI3K-Akt-m TOR信号通路,并减少高糖所致的足细胞肾病蛋白减少和足细胞凋亡。

Objective To explore the effects of C peptide on nephrin and apotosis in podocyte under high glucose. Methods Podocytes were divided into four groups： the control group （5 mmol/L glucose）, the high glucose group （25 mmol/L glucose）, the C peptide group（HG＋C peptide）, and the pertussis toxin （PTX） group （HG＋C peptide＋PTX）. 24 hours after the intervention, the levels of phosphatidylinositol 3-kinase （PI3K）, protein kinase B （Akt） and mTOR protein were detected by use of Western blotting method. The levels of nephropathy protein were detected by immunofluoreseence. Podocyte apoptosis was detected by one-step method of TUNEL. Results 5 nmol/L C peptide could significantly inhibit the expression of podocyte mTOR （P 〈 0.01）. Compared with the control group, the levels of PI3K, Akt and mTOR in the high glucose group increased greatly （P 〈 0.05）, the levels of nephropathy protein decreased significantly （P 〈 0.01）, and podocyte apoptosis obviously increased （P 〈 0.01）; compared with the high glucose group, C peptide could reverse the above changes caused by high glucose （P 〈 0.01）, while PTX could eliminate or weaken the above reverse effect of C peptide （P 〈 0.05）. Conclusion C peptide can inhibit the podocyte PI3K-Akt-mTOR signal channel activated by high glucose and lower the reduction of podocyte nephropathy protein and podocyte apoptosis.