高浓度葡萄糖损伤人腹膜间皮细胞分子机制的研究

目的：探讨高浓度葡萄糖损伤人腹膜间皮细胞的机制。方法：（1）人腹膜间皮细胞分别经含1．5％、2．5％、4．25％葡萄糖的M199培养基培养48小时后，检测间皮细胞线粒体膜电位（Ψ）、凋亡率、caspase-3活性、bax和bcl-2基因mRNA表达；（2）分别用0．1μmol／L和0．01μmol／L环孢素A（CsA）与4．25％葡萄糖共同作用人腹膜间皮细胞，检测细胞凋亡率和caspase-3活性。结果：（1）随着葡萄糖浓度增加，Ψ丧失的细胞百分率、bax mRNA表达量、caspase-3活性、凋亡率增加（P〈0．05），而bcl-2 mRNA表达量减少；（2）随着葡萄糖浓度增加，bax mRNA的表达量与皿丧失的间皮细胞百分率呈显著正相关（P〈0．01）；bcl-2 mRNA的表达量与Ψ丧失的间皮细胞百分率呈显著负相关（P〈0．01），Ψ丧失的间皮细胞百分率与间皮细胞凋亡率、caspase-3活性呈显著正相关（P〈0．01）：（3）0．1μmol／L CsA组间皮细胞凋亡率和caspase-3活性显著低于高糖对照组（P〈0．05）。结论：（1）高糖可能通过上调bax基因表达和下调bcl-2基因表达，诱导人腹膜间皮细胞线粒体活化、caspase-3活化和凋亡。（2）高糖诱导人腹膜间皮细胞caspase-3活化和凋亡可能依赖于线粒体活化。

The study on molecular mechanism of high-glucose-inducing injury to human peritoneal mesothelial cells

Objective: To investigate mechanism of high-glucose-inducing injury to human peritoneal mesothelial cells. Methods: (1)The mesothelial cells were exposed to culture medium containing different concentrations of glucose (1.5%,2.5%,4.25%) for 48 hours。 Then mitochondrial membrane potential(Ψ) , the apoptotic rate, caspase-3 activity, the level of bax mRNA and bcl-2 mRNA expression were measured. (2) The mesothelial cells were exposed to 4.25% glucose culture medium containing different concentrations of cyclosporin A (0.01, 0.1μmol/L) for 24 hours. Then the apoptotic rate and caspase-3 activity were measured. Results: (1) The level of bax mRNA expression of mesothelial cells, the percentage of mesothelial cells with loss of Ψ, caspase-3 activity of mesothelial cells, the apoptotic rate of mesothelial cells rose as glucose concentration increased, but the level of bcl-2 mRNA expression was decreased as glucose concentration increased(P<0.01). (2) There was significantly positive correlation among the level of bax mRNA expression, the percentage of mesothelial cells with loss of Ψ, caspase-3 activity and the apoptotic rate . (3) Apoptotic rate and caspase-3 activity was significantly lower in 0.1μmol/L CsA group than that in control. Conclusion: (1) High-glucose could induce loss of Ψ, apoptosis and caspase-3 activation of human peritoneal mesothelial cells by up-regulating expression of bax and down-regulating expression of bcl-2. (2)High-glucose could induce Caspase-3 activation in progression of high-glucose-inducing apoptosis of human peritoneal mesothelial cells by mitochondria activation.