Potentiation of cystic fibrosis transmembrane conductance regulator (CFTR) Cl- currents by the chemical solvent tetrahydrofuran.
Potentiation of cystic fibrosis transmembrane conductance regulator (CFTR) Cl- currents by the chemical solvent tetrahydrofuran.
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化学溶剂四氢呋喃增强囊性纤维化跨膜电导调节器 (CFTR) Cl-电流。
DOI：
10.1080/09687680802487967
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发表时间：
2008
影响因子：
--
通讯作者：
Hughes LK
中科院分区：
文献类型：
--
作者：
Hughes LK
化学溶剂四氢呋喃（THF）增加肾上皮内源性表达囊性纤维化跨膜传导调节因子（CFTR）的短路电流（Isc）。为了了解THF如何增加Isc，我们使用了ususing chamber和膜片钳技术来研究表达重组人CFTR的细胞。THF增加Iscin Fischer大鼠甲状腺（FRT）上皮表达野生型CFTR，一半最大有效浓度（KD）为134 mM。在表达囊性纤维化突变体F508del-和G551D-CFTR的FRT上皮中，四氢呋喃（10µM）增强了这种thf诱导的iscs升高，被PKA抑制剂H-89（10µM）和噻唑烷酮CFTRinh-172（10µM）抑制，并大大减弱。相比之下，THF （100 mM）对未转染的FRT上皮没有影响，而其他溶剂未能增加表达野生型CFTR的Iscin FRT上皮。在切除的内外膜斑块中，THF （100 mM）通过增加通道打开的频率而不改变其持续时间，增强了单独存在ATP （1 mM）的CFTR Cl -通道的打开。然而，在PKA （75 nM）磷酸化CFTR后，THF （100 mM）没有增强通道活性。利用不受pka依赖性磷酸化调控的R-S660A-CFTR Cl -通道，以及使用比ATP更有效地抑制野生型CFTR的2 '脱氧-ATP，也获得了类似的结果。我们的数据表明，THF直接作用于CFTR以增强通道门控，但其效力较弱且依赖于CFTR的磷酸化状态。
The chemical solvent tetrahydrofuran (THF) increases short-circuit current (Isc) in renal epithelia endogenously expressing the cystic fibrosis transmembrane conductance regulator (CFTR). To understand how THF increases Isc, we employed the Ussing chamber and patch-clamp techniques to study cells expressing recombinant human CFTR. THF increased Iscin Fischer rat thyroid (FRT) epithelia expressing wild-type CFTR with half-maximal effective concentration (KD) of 134 mM. This THF-induced increase in Iscwas enhanced by forskolin (10 µM), inhibited by the PKA inhibitor H-89 (10 µM) and the thiazolidinone CFTRinh-172 (10 µM) and attenuated greatly in FRT epithelia expressing the cystic fibrosis mutants F508del- and G551D-CFTR. By contrast, THF (100 mM) was without effect on untransfected FRT epithelia, while other solvents failed to increase Iscin FRT epithelia expressing wild-type CFTR. In excised inside-out membrane patches, THF (100 mM) potentiated CFTR Cl−channels open in the presence of ATP (1 mM) alone by increasing the frequency of channel openings without altering their duration. However, following the phosphorylation of CFTR by PKA (75 nM), THF (100 mM) did not potentiate channel activity. Similar results were obtained with the ▵R-S660A-CFTR Cl−channel that is not regulated by PKA-dependent phosphorylation and using 2′deoxy-ATP, which gates wild-type CFTR more effectively than ATP. Our data suggest that THF acts directly on CFTR to potentiate channel gating, but that its efficacy is weak and dependent on the phosphorylation status of CFTR.