Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany.
Institute for Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
Sci Rep. 2017 Jun 14;7(1):3517. doi: 10.1038/s41598-017-03742-5.
Hydrogen sulfide (HS) has been recognized as a signalling molecule which affects the activity of ion channels and transporters in epithelial cells. The cystic fibrosis transmembrane conductance regulator (CFTR) is an epithelial anion channel and a key regulator of electrolyte and fluid homeostasis. In this study, we investigated the regulation of CFTR by HS. Human CFTR was heterologously expressed in Xenopus oocytes and its activity was electrophysiologically measured by microelectrode recordings. The HS-forming sulphur salt NaS as well as the slow-releasing HS-liberating compound GYY4137 increased transmembrane currents of CFTR-expressing oocytes. NaS had no effect on native, non-injected oocytes. The effect of NaS was blocked by the CFTR inhibitor CFTR_inh172, the adenylyl cyclase inhibitor MDL 12330A, and the protein kinase A antagonist cAMPS-Rp. NaS potentiated CFTR stimulation by forskolin, but not that by IBMX. NaS enhanced CFTR stimulation by membrane-permeable 8Br-cAMP under inhibition of adenylyl cyclase-mediated cAMP production by MDL 12330A. These data indicate that HS activates CFTR in Xenopus oocytes by inhibiting phosphodiesterase activity and subsequent stimulation of CFTR by cAMP-dependent protein kinase A. In epithelia, an increased CFTR activity may correspond to a pro-secretory response to HS which may be endogenously produced by the epithelium or HS-generating microflora.
硫化氢 (HS) 已被确认为一种信号分子，它影响上皮细胞中离子通道和转运体的活性。囊性纤维化跨膜电导调节剂 (CFTR) 是一种上皮阴离子通道，也是电解质和液体动态平衡的关键调节剂。在这项研究中，我们研究了 HS 对 CFTR 的调节作用。人 CFTR 在非洲爪蟾卵母细胞中异源表达，并通过微电极记录进行电生理测量来测量其活性。形成 HS 的硫盐 NaS 以及缓慢释放 HS 的化合物 GYY4137 增加了 CFTR 表达卵母细胞的跨膜电流。NaS 对天然的、未注射的卵母细胞没有影响。NaS 的作用被 CFTR 抑制剂 CFTR_inh172、腺苷酸环化酶抑制剂 MDL 12330A 和蛋白激酶 A 拮抗剂 cAMPS-Rp 阻断。NaS 增强了 forskolin对 CFTR 的刺激作用，但对 IBMX 没有作用。NaS 增强了在 MDL 12330A 抑制腺苷酸环化酶介导的 cAMP 产生的情况下，膜通透性 8Br-cAMP 对 CFTR 的刺激作用。这些数据表明，HS 通过抑制磷酸二酯酶活性并随后通过 cAMP 依赖性蛋白激酶 A 刺激 CFTR，在上皮细胞中激活 CFTR。在上皮细胞中，CFTR 活性的增加可能对应于对 HS 的促分泌反应，这种反应可能是由上皮细胞或产生 HS 的微生物群落内源产生的。
