Purinoceptor-coupled Cl- channels in mouse heart:: a novel, alternative pathway for CFTR regulation
Purinoceptor-coupled Cl- channels in mouse heart:: a novel, alternative pathway for CFTR regulation
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DOI：
10.1111/j.1469-7793.1999.00043.x
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发表时间：
1999-11-15
影响因子：
5.5
通讯作者：
Hume, JR
中科院分区：
文献类型：
--
作者：
Duan, DY;Ye, LY;Hume, JR
1. P-2-嘌呤受体偶联细胞外ATP激活心脏中的Cl-电流（I-Cl，I-ATP）。研究了I-Cl、I-ATP激活小鼠心脏的分子机制和细胞内信号通路.细胞外腺苷-5 '-O-（3-硫代三磷酸）（ATP γ S; 100 μ M）激活心房和心室肌细胞中的I-Cl、I-ATP。一个特定的PKC抑制剂，双吲哚马来酰亚胺阻断ATP γ S的作用，而PRC激活剂，佛波醇12，13-二丁酸酯（PDBu）激活电流与I-Cl，I-ATP相同的属性。ATP γ S或PDBu对I-Cl、I-ATP的最大激活阻断了其他激动剂的进一步调节，表明它们可能激活相同的Cl-通道群。异丙肾上腺素增加I-Cl，I-ATP预激活的ATP γ S或PDBu，而异丙肾上腺素或毛喉素单独未能激活任何Cl-电流在这些心肌细胞。腺苷3 '，5'-环单硫代磷酸盐，PKA抑制剂，阻止ATP γ S或I-Cl，I-ATP的PDBu激活。因此，I-Cl、I-ATP通过涉及PKA和PKC的双重细胞内磷酸化途径以类似于囊性纤维化跨膜传导调节因子（CFTR）Cl-通道的协同方式调节。格列本脲（50 μ M）可显著阻断ATP γ S或CFTR通道激活剂左旋咪唑激活的I-Cl、I-ATP。在细胞贴附的贴片中，单位I-Cl，I-ATP的斜率电导为11.8 +/- 0.3 pS，类似于心肌细胞中CFTR Cl-通道的已知特性。逆转录聚合酶链反应和北方印迹分析显示CFTR mRNA在小鼠心脏中有表达.我们认为，I-Cl，I-ATP在小鼠心脏中通过一种新的细胞内信号通路激活CFTR Cl-通道，该通路涉及PKC和PKA的嘌呤能激活。
1. P-2-purinoceptors couple extracellular ATP to the activation of a Cl- current (I-Cl,I- ATP) in heart. We studied the molecular mechanism and intracellular signalling pathways of I-Cl,I-ATP activation in mouse heart.2. Extracellular adenosine-5'-O-(3-thiotriphosphate) (ATP gamma S; 100 mu M) activated I-Cl,I-ATP in both atrial and ventricular myocytes. A specific PKC inhibitor, bisindolylmaleimide blocked the effect of ATP gamma S while a PRC activator, phorbol 12,13-dibutyrate (PDBu) activated a current with identical properties to I-Cl,I-ATP. Maximal activation of I-Cl,I-ATP by ATP gamma S or PDBu occluded further modulation by the other agonist, suggesting that they may activate the same population of Cl- channels.3. Isoprenaline increased I-Cl,I-ATP pre-activated by ATP gamma S or PDBu, while isoprenaline or forskolin alone failed to activate any Cl- current in these myocytes. Adenosine 3',5'-cyclic monophosphothionate, a PKA inhibitor, prevented ATP gamma S or PDBu activation of I-Cl,I-ATP. Thus, I-Cl,I-ATP is regulated by dual intracellular phosphorylation pathways involving both PKA and PKC in a synergistic manner similar to cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels.4. Glibenclamide (50 mu M) significantly blocked I-Cl,I-ATP activated by ATP gamma S or by the CFTR channel activator, levamisole.5. The slope conductance of the unitary I-Cl,I-ATP in cell-attached patches was 11.8 +/- 0.3 pS, resembling the known properties of CFTR Cl- channels in cardiac myocytes.6. The reverse transcription polymerase chain reaction and Northern blot analysis revealed CFTR mRNA expression in mouse heart.7. We conclude that I-Cl,I-ATP in mouse heart is clue to activation of CFTR Cl- channels through a novel intracellular signalling pathway involving purinergic activation of PKC and PKA.