SLC26A9 is a constitutively active, CFTR-regulated anion conductance in human bronchial epithelia.
SLC26A9 is a constitutively active, CFTR-regulated anion conductance in human bronchial epithelia.
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DOI：
10.1085/jgp.200810097
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发表时间：
2009-04
期刊：
影响因子：
--
通讯作者：
Frizzell RA
中科院分区：
文献类型：
--
作者：
Bertrand CA;Zhang R;Pilewski JM;Frizzell RA
人支气管上皮（HBE）细胞表现出在囊性纤维化（CF）患者的细胞中不存在的组成性阴离子分泌。这种传导的身份是未知的，但SLC 26 A9，CF跨膜传导调节因子（CFTR）相互作用转运蛋白的SLC 26家族的成员，在人类气道中发现，并表现出氯离子通道行为。我们寻求在HEK 293（HEK）细胞中表达的SLC 26 A9和CFTR的性质的差异作为指纹以鉴定HBE顶端阴离子电导。表达SLC 26 A9的HEK细胞显示出组成性氯电流，其被CFTR阻断剂GlyH-101（71 ± 4%，50 µM）抑制，并在阻断期间显示出近线性的电流-电压（I-V）关系，而GlyH-101抑制的野生型（wt）CFTR显示出强烈的内向整流（IR）I-V关系。我们测试了内源性表达wt或ΔF508-CFTR的极化HBE细胞的相似活性。在使用基底外侧α-毒素透化对顶膜进行电隔离后，wtCFTR单层显示出被GlyH-101抑制（68 ± 6%）的组成性氯电流，同时保持近线性的I-V关系。在不存在阻断剂的情况下，添加毛喉素刺激具有线性I-V的电流增加; GlyH-101阻断了69 ± 7%的电流并使I-V关系IR偏移，与CFTR激活一致。共表达SLC 26 A9和wtCFTR的HEK细胞显示出相似的特性，以及毛喉素刺激电流超过分别表达SLC 26 A9或wtCFTR的细胞中的电流之和，并且GlyH-101抑制期间的I-V关系为中度IR，表明SLC 26 A9对刺激电流有贡献。CF患者HBE细胞表达SLC 26 A9 mRNA，但无组成性氯电流。共表达SLC 26 A9与ΔF508-CFTR的HEK细胞也未能表现出SLC 26 A9电流。我们的结论是，SLC 26 A9的功能作为一个阴离子电导在HBE细胞的顶端膜，它有助于跨上皮氯电流的基础和cAMP/蛋白激酶A刺激的条件下，其在HBE细胞的活性需要功能CFTR。
Human bronchial epithelial (HBE) cells exhibit constitutive anion secretion that is absent in cells from cystic fibrosis (CF) patients. The identity of this conductance is unknown, but SLC26A9, a member of the SLC26 family of CF transmembrane conductance regulator (CFTR)-interacting transporters, is found in the human airway and exhibits chloride channel behavior. We sought differences in the properties of SLC26A9 and CFTR expressed in HEK 293 (HEK) cells as a fingerprint to identify HBE apical anion conductances. HEK cells expressing SLC26A9 displayed a constitutive chloride current that was inhibited by the CFTR blocker GlyH-101 (71 ± 4%, 50 µM) and exhibited a near-linear current–voltage (I-V) relation during block, while GlyH-101–inhibited wild-type (wt)CFTR exhibited a strong inward-rectified (IR) I-V relation. We tested polarized HBE cells endogenously expressing either wt or ΔF508-CFTR for similar activity. After electrical isolation of the apical membrane using basolateral α-toxin permeabilization, wtCFTR monolayers displayed constitutive chloride currents that were inhibited by GlyH-101 (68 ± 6%) while maintaining a near-linear I-V relation. In the absence of blocker, the addition of forskolin stimulated a current increase having a linear I-V; GlyH-101 blocked 69 ± 7% of the current and shifted the I-V relation IR, consistent with CFTR activation. HEK cells coexpressing SLC26A9 and wtCFTR displayed similar properties, as well as forskolin-stimulated currents that exceeded the sum of those in cells separately expressing SLC26A9 or wtCFTR, and an I-V relation during GlyH-101 inhibition that was moderately IR, indicating that SLC26A9 contributed to the stimulated current. HBE cells from CF patients expressed SLC26A9 mRNA, but no constitutive chloride currents. HEK cells coexpressing SLC26A9 with ΔF508-CFTR also failed to exhibit SLC26A9 current. We conclude that SLC26A9 functions as an anion conductance in the apical membranes of HBE cells, it contributes to transepithelial chloride currents under basal and cAMP/protein kinase A–stimulated conditions, and its activity in HBE cells requires functional CFTR.
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DOI：
10.1085/jgp.200409059
发表时间：
2004-08
期刊：
The Journal of general physiology
影响因子：
--
作者：
Muanprasat C;Sonawane ND;Salinas D;Taddei A;Galietta LJ;Verkman AS
通讯作者：
Verkman AS
DOI：
10.1152/ajplung.00036.2004
发表时间：
2004-12-01
影响因子：
4.9
作者：
Krouse, ME;Talbott, JF;Wine, JJ
通讯作者：
Wine, JJ
影响因子：
5.5
作者：
Hallows, KR;Kobinger, GP;Foskett, JK
通讯作者：
Foskett, JK
影响因子：
5.5
作者：
Song, YL;Salinas, D;Verkman, AS
通讯作者：
Verkman, AS
影响因子：
--
作者：
OSTEDGAARD, LS;SHASBY, DM;WELSH, MJ
通讯作者：
WELSH, MJ