Yang Xiaoya, Zhao Chan, Mahdy Sana'a A, Xu Peisheng, Yu Meisheng, Wu Jiabao, Wang Liang, Jacob Tim J, Zhu Linyan, Peng Shuang, Deng Zhiqin, Chen Lixin, Wang Liwei
Department of Physiology, Medical College, Jinan University, Guangzhou, 510632, China; Department of Pathophysiology, Medical College, Jinan University, Guangzhou, 510632, China.
Department of Physiology, Medical College, Jinan University, Guangzhou, 510632, China.
Biochem Biophys Res Commun. 2020 Jun 4;526(3):592-598. doi: 10.1016/j.bbrc.2020.03.115. Epub 2020 Apr 1.
Extracellular acidification, playing a promoting role in the process of acute pancreatitis, has been reported to activate Cl channels in several types of cells. However, whether extracellular acidification aggravates acute pancreatitis via activating Cl channels remains unclear. Here, we investigated the effects of extracellular acidification on Cl channels in rat pancreatic acinar AR42J cells using whole-cell patch-clamp recordings. We found that extracellular acidification induced a moderately outward-rectified Cl current, with a selectivity sequence of I > Br ≥ Cl > gluconate, while intracellular acidification failed to induce the currents. The acid-sensitive currents were inhibited by Cl channel blockers, 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate and 5-Nitro-2-(3-phenylpropylamino) benzoic acid. After ClC-3 was silenced by ClC-3 shRNA, the acid-sensitive Cl currents were attenuated significantly, indicating that ClC-3 plays a vital role in the induction of acid-sensitive Cl currents. Extracellular acid elevated the intracellular level of reactive oxygen species (ROS) significantly, prior to inducing Cl currents. When ROS production was scavenged, the acid-sensitive Cl currents were abolished. Whereas, the level of acid-induced ROS was unaffected with silence of ClC-3. Our findings above demonstrate that extracellular acidification induces a Cl current in pancreatic acinar cells via promoting ROS generation, implying an underlying mechanism that extracellular acidification might aggravate acute pancreatitis through Cl channels.
细胞外酸化在急性胰腺炎过程中起促进作用，据报道它可激活多种类型细胞中的氯离子通道。然而，细胞外酸化是否通过激活氯离子通道加重急性胰腺炎仍不清楚。在此，我们使用全细胞膜片钳记录技术研究了细胞外酸化对大鼠胰腺腺泡AR42J细胞中氯离子通道的影响。我们发现细胞外酸化诱导出一种适度外向整流的氯离子电流，其选择性顺序为I＞Br≥Cl＞葡萄糖酸盐，而细胞内酸化未能诱导出该电流。酸敏感电流受到氯离子通道阻滞剂二硫代二苯乙烯二磺酸二钠盐和5-硝基-2-(3-苯丙基氨基)苯甲酸的抑制。用ClC-3短发夹RNA使ClC-3沉默后，酸敏感的氯离子电流显著减弱，表明ClC-3在酸敏感氯离子电流的诱导中起关键作用。在诱导氯离子电流之前，细胞外酸化显著提高了细胞内活性氧(ROS)水平。当清除ROS生成时，酸敏感的氯离子电流消失。然而，ClC-3沉默并不影响酸诱导的ROS水平。我们上述研究结果表明，细胞外酸化通过促进ROS生成诱导胰腺腺泡细胞中的氯离子电流，这意味着细胞外酸化可能通过氯离子通道加重急性胰腺炎的潜在机制。
