【摘要】 目的探讨容量敏感外向整流性(VSOR)氯通道在H2O2介导系膜细胞凋亡中的作用和可能的机制。方法全细胞膜片钳技术用于检测VSOR氯电流。细胞凋亡通过吖啶橙／溴化乙锭荧光染色、电子显微镜、TUNEL染色和半胱氨酸天冬氨酸蛋白酶(caspase)-3活性确定。结果150μmol／L H2O2激活系膜细胞VSOR氯电流,H2O2激活的氯电流具有典型的VSOR氯电流电生理特性。包括:外向整流性、电压依赖性失活。对细胞外高渗透压敏感及被VSOR氯通道阻断剂抑制。VSOR氯通道阻断剂DIDS(100μmol／L),NPPB(10μmol／L)和尼氟灭酸(10μmol／L)明显抑制H2O2介导的系膜细胞凋亡。150μmol／L H2O2处理2 h内,细胞容量明显下降,但这种细胞容量下降被100μmol／L DIDS,10μmol／L NPPB和10μmol／L尼氟灭酸抑制。结论VSOR氯通道参与H2O2介导的系膜细胞凋亡,其机制与介导凋亡性容量下降有关。更多还原

【Abstract】 Objective To investigate the role of volume-sensitive outwardly rectifying (VSOR) chloride channels in mesangial cell apoptosis induced by H2O2. Methods VSOR chloride current was recorded in whole cell configuration. The apoptosis was evaluated by AO/EB staining, transmission electron microscopy, TUNEL staining and caspase-3 activity. Cell volume was measured by Lag-time microphotography. Results Application of 150μmol/L H2O2 led to activation of VSOR Cl-1 conductance in mesangial cells. H2O2-induced Cl- current showed phynotypical properties of VSOR Cl- channels, including outward rectification, voltage-dependant inactivation at large positive potentials, sensitiveness to hyperosmolarity,inhibition by VSOR Cl- channel blockers. Moreover, blockage of VSOR Cl- by DIDS (100μmol/L), NPPB(10μmoI/L) or niflumic acid (10μmol/L) rescued mesangial cells from H2O2-induced apoptotic cell death. Treatment for 2 hours with 150μmol/L H2O2 resulted in significant reduction in cell volume. However, the early-phase alterations in cell volume were markedly abolished by pretreatment with VSOR Cl- channel blockers. Conclusion VSOR Cl-channels are involved in H2O2-induced apoptosis of mesangial cells and its mechanism is associated with the decrease of apoptotic volume (AVD).更多还原