Characterization of Cardiac Anoctamin1 Ca2+-Activated Chloride Channels and Functional Role in Ischemia-Induced Arrhythmias

• Type of Material: Article
• Authors: Zhen Ye, Harbin Medical University; Ming-Ming Wu, Harbin Medical University; Chun-Yu Wang, Harbin Medical University; Yan-Chao Li, Harbin Medical University; Chang-Jiang Yu, Harbin Medical University; Yuan-Feng Gong, Harbin Medical University; Jun Zhang, Harbin Medical University; Qiu-Shi Wang, Harbin Medical University; Bin-Lin Song, Harbin Medical University; Kuai Yu, Emory University; Criss Hartzell Jr., Emory University; Dayue Darrel Duan, University of Nevada; Dan Zhao, Harbin Medical University; Zhi-Ren Zhang, Harbin Medical University
• Language: English
• Date: 2015-02-01
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 Wiley Periodicals, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1002/jcp.24709
• Title of Journal or Parent Work: Journal of Cellular Physiology
• ISSN: 0021-9541
• Volume: 230
• Issue: 2
• Start Page: 337
• End Page: 346
• Grant/Funding Information: This study was supported by Key Project of Chinese National Program for Fundamental Research and Development (973 Program 2012CB517803, 2014CB542401 to Z. Z.); NSFC (30871007, 81070217 to Z. Z.); Doctoral Tutor Foundation of Ministry of Education (20122307110008 to Z. Z.); the Natural Science Foundation of Heilongjiang Province (ZD200807-01, ZD200807-02 to Z. Z. and QC2010097 to D. Z.); Overseas Talent Foundation of Department of Education, Heilongjiang Province (1154HZ11 to Z. Z.); and Science Research Foundation of Graduate School of HMU (YJSCX2011-336 to Z. Y.).; This study was also supported by AHA Western States Affiliate Grant-in-Aid (11GRNT7610161 to D. D.); and the NIH Grant (HL106256 to D. D.).
• Keywords: CURRENTS; HEART; Life Sciences & Biomedicine; Cell Biology; PHENOMICS; SMOOTH-MUSCLE-CELLS; TMEM16A; SINGLE PURKINJE; Physiology; CL-CHANNELS; ATRIAL MYOCYTES; CANINE VENTRICULAR MYOCYTES; DELAYED AFTERDEPOLARIZATIONS; Science & Technology
• Research Categories: Biology, Cell; Biology, Physiology; Health Sciences, Pharmacology

Abstract

Anoctamin1 (ANO1) encodes a Ca2+-activated chloride (Cl-) channel (CaCC) in variety tissues of many species. Whether ANO1 expresses and functions as a CaCC in cardiomyocytes remain unknown. The objective of this study is to characterize the molecular and functional expression of ANO1 in cardiac myocytes and the role of ANO1-encoded CaCCs in ischemia-induced arrhythmias in the heart. Quantitative real-time RT-PCR, immunofluorescence staining assays, and immunohistochemistry identified the molecular expression, location, and distribution of ANO1 in mouse ventricular myocytes (mVMs). Patch-clamp recordings combined with pharmacological analyses found that ANO1 was responsible for a Ca2+-activated Cl- current (ICl.Ca) in cardiomyocytes. Myocardial ischemia led to a significant increase in the current density of ICl.Ca, which was inhibited by a specific ANO1 inhibitor, T16Ainh-A01, and an antibody targeting at the pore area of ANO1. Moreover, cardiomyocytes isolated from mice with ischemia-induced arrhythmias had an accelerated early phase 1 repolarization of action potentials (APs) and a deeper "spike and dome" compared to control cardiomyocytes from non-ischemia mice. Application of the antibody targeting at ANO1 pore prevented the ischemia-induced early phase 1 repolarization acceleration and caused a much shallower "spike and dome". We conclude that ANO1 encodes CaCC and plays a significant role in the phase 1 repolarization of APs in mVMs. The ischemia-induced increase in ANO1 expression may be responsible for the increased density of ICl.Ca in the ischemic heart and may contribute, at least in part, to ischemia-induced arrhythmias.