A chloride channel in rat pancreatic acinar AR42J cells is sensitive to extracellular acidification and dependent on ROS

• Published in: Biochemical and biophysical research communications Vol. 526; no. 3; pp. 592 - 598
• Main Authors: 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
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 04.06.2020
• Subjects: Acidification; Acinar Cells - cytology; Acinar Cells - metabolism; Acute pancreatitis; Animals; Cell Line; Chloride channels; Chloride Channels - metabolism; Chlorides - metabolism; ClC-3; Extracellular pH; Extracellular Space - metabolism; Hydrogen-Ion Concentration; Pancreas - cytology; Pancreas - metabolism; Patch-Clamp Techniques; Rats; Reactive oxygen species; Reactive Oxygen Species - metabolism; Acidification; Chloride channels; ClC-3; Reactive oxygen species; Acute pancreatitis; Extracellular pH
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2020.03.115

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. •A chloride channel in AR42J cells was sensitive to extracellular acidification.•ClC-3 played a vital role in the induction of the acid-sensitive Cl− currents.•Reactive oxygen species involved in inducing the acid-sensitive Cl− currents.