The chloride channel ClC-2 contributes to the inwardly rectifying Cl- conductance in cultured porcine choroid plexus epithelial cells
The chloride channel ClC-2 contributes to the inwardly rectifying Cl- conductance in cultured porcine choroid plexus epithelial cells
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DOI：
10.1111/j.1469-7793.2000.t01-1-00313.x
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发表时间：
2000-03-01
影响因子：
5.5
通讯作者：
Matsuda, H
中科院分区：
文献类型：
--
作者：
Kajita, H;Omori, K;Matsuda, H
用Western分析和全细胞电流记录技术研究了ClC-2蛋白对培养的猪脉络丛上皮细胞内向整流Cl-电导的影响，在细胞内蛋白激酶A（PKA）存在的情况下，超极化电压负于-50 mV时，ClC-2蛋白可引起内向整流Cl-电导。根据翻转电位的变化（E-rev）估算出相对卤离子选择性为I- > Br- > Cl- > F-。细胞外血管活性肠肽（VIP）以剂量依赖的方式激活相同的电流，其半最大浓度为167.3 nM。H-89 ClC-2可被外源性Cd ~（2+）、B ~（2+）或H ~+所抑制，但仅被已知的Cl ~-通道阻断剂格列本脲、NPPB、DIDS和蒽-9-羧酸（SAC）所微弱抑制。在用ClC-2的反义寡脱氧核苷酸处理的细胞中其减少。PKA和VIP均不能激活转染反义寡核苷酸的细胞的内向整流性Cl-电流，而在单独转染GFP或转染反义寡核苷酸随机化的对照寡核苷酸的细胞中，它们都能激活内向整流性Cl-电流，说明ClC-2蛋白参与了猪脉络丛上皮细胞内向整流性Cl-电流的传导。
The contribution of ClC-2 protein to the inwardly rectifying Cl- conductance in cultured porcine choroid plexus epithelial cells was investigated using Western analysis and whole-cell current recordings.Inwardly rectifying currents were elicited by hyperpolarizing voltage at a potential more negative than -50 mV in the presence of intracellular protein kinase A (PKA). The relative halide selectivity estimated from the shift in the reversal potential (E-rev) was I- > Br- > Cl- > F-.Extracellular vasoactive intestinal peptide (VIP) activated the same currents in a dose-dependent manner with a half-maximal concentration of 167.3 nM. H-89 (a PKA inhibitor) interfered with the current activation by VIP.The Cl- channel was inhibited by external Cd2+, B2+ or H+, but only weakly inhibited by known Cl- channel blockers including glibenclamide, NPPB, DIDS and anthracene-9-carboxylic acid (SAC).A specific antibody to ClC-2 detected a 79 kDa protein in porcine choroid plexus cells, which was reduced in cells treated with antisense oligodeoxynucleotide for ClC-2. Both PKA and VIP failed to activate the inwardly rectifying Cl- currents in cells transfected with the antisense oligodeoxynucleotide, while they activated the currents in cells transfected with GFP alone or the control oligodeoxynucleotide randomized from antisense oligonucleotide.It is concluded that ClC-2 protein contributes to the inwardly rectifying Cl- conductance in porcine choroid plexus epithelial cells.