Modulation of Staurosporine-Activated Volume-Sensitive Outwardly Rectifying Cl- Channel by PI3K/Akt in Cardiomyocytes
Modulation of Staurosporine-Activated Volume-Sensitive Outwardly Rectifying Cl- Channel by PI3K/Akt in Cardiomyocytes
复制标题
PI3K/Akt 对心肌细胞中十字孢菌素激活的体积敏感型外向整流 Cl 通道的调节
DOI：
10.2174/1381612811319270008
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发表时间：
2013-08-01
影响因子：
3.1
通讯作者：
Ren, Jun
中科院分区：
文献类型：
--
作者：
Liu, Yan;Wang, Bo;Ren, Jun
氯离子（Cl-）通道参与应激时心脏功能的调节，但其潜在的调节机制仍知之甚少。本研究旨在探讨促凋亡刺激物星形孢菌素（staurosporine，STS）对心肌细胞体积敏感性外向整流氯电流（volume-sensitive outwardly rectifying Cl-current，I-Cl，I-Or）的影响及其可能的调节机制，重点研究了磷脂酰肌醇-3激酶（phosphatidylinositol-3 kinase，PI 3 K）/Akt的作用。原代培养的大鼠乳鼠心肌细胞分别置于低渗和等渗环境中，在STS存在或不存在的情况下，进行全细胞电压钳法测定Cl（-）电流。全细胞记录显示，STS激活了一个外向整流的Cl（-）电流，其表型特征使人联想到ICl，Vol。这些电流在正电位下是外向整流的，具有时间依赖性失活，并且对非选择性Cl（-）通道阻断剂4，4 '-二异硫氰基-纳托芪-2，2'-二磺酸（DIDS）和4-氨基苯磺酸敏感。（2-丁基-6，7-异丙基-2-环戊基-茚满-1-酮-5-基）氧基丁酸（DCPIB），一种选择性VSOR Cl-通道阻滞剂。DIDS和DCPIB对I-Cl、I-Cl的抑制率分别为92.6% +/- 7.3%和78.4% +/-5.5%。我们的数据进一步揭示了PI 3 K抑制剂LY 294002促进了电流的峰值幅度为19.54 +/- 2.70 pA/pF。相反，胰岛素部分抑制了电流的峰值幅度为15.4 +/- 2.13 pA/pF。在心肌细胞中可能通过PI 3 K/Akt依赖性机制介导的β-CD）通道。
Chloride (Cl-) channels participate in the regulation of cardiac function in response to stress although the underlying regulatory mechanism remains poorly understood. This study was designed to examine the impact of the pro-apoptotic stimulus staurosporine (STS) on the volume-sensitive outwardly rectifying Cl-current (I-Cl,I-Vol) in cardiomyocytes and possible regulatory mechanism involved with a focus on phosphatidylinositol-3 kinase (PI3K)/Akt. Primary cultured rat neonatal cardiomyocytes were subjected to hypotonic and isotonic environment in the presence or absence of STS prior to whole-cell voltage-clamp evaluation of Cl(-)current. Whole-cell recordings revealed that STS activated an outwardly rectifying Cl(-)current with phenotypic properties reminiscent of ICl, Vol. These currents were outwardly rectifying with a time-dependent inactivation at positive potentials and were sensitive to 4,4'-diisothiocya-natostilbene-2,2'-disulfonicacid (DIDS), a non-selective Cl(-)channel blocker, and 4-(2-butyl-6,7-dichlor-2-cyclopentyl-indan-1-on-5-yl) oxybutyric acid (DCPIB), a selective VSOR Cl- channel blocker. DIDS and DCPIB inhibited I-Cl,I-Vol by 92.6% +/- 7.3% and 78.4% +/- 5.5%, respectively. Our data further revealed that the PI3K inhibitor LY294002 facilitated the current with the peak amplitude of 19.54 +/- 2.70 pA/pF. To the contrary, insulin partially inhibited the current amplitude with the peak current amplitude of 15.4 +/- 2.13 pA/pF. Taken together, our data depicted staurosporine is capable of activating (ICl,Vol) channel in cardiomyocytes via possibly a PI3K/Akt-dependent mechanism.