高糖环境对大鼠肾小球系膜细胞AMPK表达及活性的影响

 目的 观察高糖环境下肾小球系膜细胞AMP活化蛋白激酶（AMPK）表达和活性的变化及这种变化与系膜细胞增殖的关系。  方法 实验分4组：对照组（糖浓度5.6mmol/L），高糖组（22.0mmol/L），低浓度5-氨基-4-氨甲酰咪唑核苷（AICAR）组（0.5mmol/L AICAR+高糖），高浓度AICAR组（1.0mmol/L AICAR+高糖）。观察24h后，应用MTT法检测细胞增殖，流式细胞仪检测细胞周期，RT-PCR法测定AMPKα1、α2亚单位mRNA水平，Westernblot法测定总AMPKα蛋白及磷酸化AMPKα蛋白水平。  结果 与对照组比较，高糖组细胞增殖趋势明显（P＜0.01），且S期的细胞百分数增加（P＜0.01）；RT-PCR显示，高糖组AMPKα1、α2亚单位的mRNA水平低于对照组；总AMPKα蛋白水平及磷酸化AMPKα蛋白水平亦较低；特异性AMPK激活剂AICAR可抑制高糖诱导的细胞增殖（P＜0.01），使S期的细胞百分数下降，并能增强AMPKα1、α2亚单位的mRNA表达水平及总AMPKα蛋白水平和磷酸化AMPKα蛋白水平。 结论  高糖环境下AMPKα1、α2 mRNA表达水平低下，AMPK蛋白的表达及活性降低;高糖诱导的系膜细胞增殖与AMPK表达及活性降低有关。

AMP-activated protein kinase in high glucose-induced proliferation of glomerular mesangial cells

Objective To investigate the expression and activity of AMPK in high glucose-induced proliferation of glomerular mesangial cells（GMCs）.
 Methods GMCs were incubated in four groups for 24 hours: the control group(glucose 5.6mmol/L), the high glucose group（glucose 22.0mmol/L）， the low AICAR group（0.5mmol/L AICAR＋22.0mmol/L glucose）， and the high AICAR group（1.0mmol/L AICAR＋22.0mmol/L glucose）. The proliferation of GMCs was determined by MTT and the cell cycle of GMCs by flow cytometry; AMPKα1 and α2 mRNA levels were observed by RT-PCR;and protein levels of AMPKα and P-AMPKα were determined by Western blot.  Results Compared with the control group, high glucose induced proliferation and DNA synthesis of GMCs with impaired AMPKα1and α2 mRNA levels and impaired protein levels of AMPKα and P- AMPKα; AICAR(activator of AMPK) suppressed high glucose-induced cell proliferation and DNA synthesis while enhancing the AMPKα1 and α2mRNA and protein levels of AMPKα and P-AMPKα.  Conclusion  High glucose can induce proliferation and DNA synthesis of GMCs, which may correlate with impaired AMPKα1 and α2 mRNA levels and impaired protein levels of AMPKα and P-AMPKα.