• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>American Journal of Physiology >Role of Ca2+-activated K+ channels in human erythrocyte apoptosis.
【24h】

Role of Ca2+-activated K+ channels in human erythrocyte apoptosis.

机译：Ca2 +激活的K +通道在人类红细胞凋亡中的作用。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Exposure of erythrocytes to the Ca2+ ionophore ionomycin has recently been shown to induce cell shrinkage, cell membrane blebbing, and breakdown of phosphatidylserine asymmetry, all features typical of apoptosis of nucleated cells. Although breakdown of phosphatidylserine asymmetry is thought to result from activation of a Ca2+-sensitive scramblase, the mechanism and role of cell shrinkage have not been explored. The present study was performed to test whether ionomycin-induced activation of Ca2+-sensitive Gardos K+ channels and subsequent cell shrinkage participate in ionomycin-induced breakdown of phosphatidylserine asymmetry of human erythrocytes. According to on-cell patch-clamp experiments, ionomycin (1 microM) induces activation of inwardly rectifying K+-selective channels in the erythrocyte membrane. Fluorescence-activated cell sorter analysis reveals that ionomycin leads to a significant decrease of forward scatter, reflecting cell volume, an effect blunted by an increase of extracellular K+ concentration to 25 mM and exposure to the Gardos K+ channel blockers charybdotoxin (230 nM) and clotrimazole (5 microM). As reflected by annexin binding, breakdown of phosphatidylserine asymmetry is triggered by ionomycin, an effect again blunted, but not abolished, by an increase of extracellular K+ concentration and exposure to charybdotoxin (230 nM) and clotrimazole (5 microM). Similar to ionomycin, glucose depletion leads (within 55 h) to annexin binding of erythrocytes, an effect again partially reversed by an increase of extracellular K+ concentration and exposure to charybdotoxin. K-562 human erythroleukemia cells similarly respond to ionomycin with cell shrinkage and annexin binding, effects blunted by antisense, but not sense, oligonucleotides against the small-conductance Ca2+-activated K+ channel isoform hSK4 (KCNN4). The experiments disclose a novel functional role of Ca2+-sensitive K+ channels in erythrocytes, i.e., their participation in regulation of erythrocyte apoptosis.
机译：最近显示，将红细胞暴露于Ca2 +离子载体离子霉素会诱导细胞收缩，细胞膜起泡以及磷脂酰丝氨酸不对称性的破坏，所有这些特征都是有核细胞凋亡的典型特征。尽管磷脂酰丝氨酸不对称性的破坏被认为是由Ca2 +敏感的scramblase的激活引起的，但尚未研究细胞收缩的机制和作用。进行本研究以测试离子霉素诱导的Ca2 +敏感的Gardos K +通道的激活和随后的细胞收缩是否参与离子霉素诱导的人红细胞磷脂酰丝氨酸不对称性的分解。根据细胞膜片钳实验，离子霉素（1 microM）诱导红细胞膜中向内整流的K +选择性通道的活化。荧光激活细胞分选仪分析表明，离子霉素导致前向散射显着减少，反映了细胞体积，这种作用因细胞外K +浓度增加至25 mM以及暴露于Gardos K +通道阻滞剂charybdotoxin（230 nM）和克霉唑而减弱（5 microM）。如膜联蛋白结合所反映，磷脂酰丝氨酸不对称性的破坏是由离子霉素引发的，这种效应通过细胞外K +浓度的增加以及暴露于charybdotoxin（230 nM）和clotrimazole（5 microM）的作用而再次减弱但没有消除。与离子霉素相似，葡萄糖耗竭导致（在55小时之内）红细胞的膜联蛋白结合，这种作用又因细胞外K +浓度增加和暴露于甲毒素而再次部分逆转。 K-562人红细胞白血病细胞类似地对离子霉素具有细胞收缩和膜联蛋白结合的反应，这种反义作用减弱了反义，但没有意义，寡核苷酸针对小传导性Ca2 +激活的K +通道亚型hSK4（KCNN4）。该实验揭示了Ca 2+敏感的K +通道在红细胞中的新功能作用，即它们参与红细胞凋亡的调节。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号