title: Characterization of Cardiac Anoctamin1 Ca²⁺-Activated Chloride Channels and Functional Role in Ischemia-Induced Arrhythmias.
abstract: Anoctamin1 (ANO1) encodes a Ca(2+)-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 Ca(2+)-activated Cl(-) current (I(Cl.Ca)) in cardiomyocytes. Myocardial ischemia led to a significant increase in the current density of I(Cl.Ca), which was inhibited by a specific ANO1 inhibitor, T16A(inh)-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 I(Cl.Ca) in the ischemic heart and may contribute, at least in part, to ischemia-induced arrhythmias.
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Zhen
authors: Z
authors: Ye
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Ming-Ming
authors: MM
authors: Wu
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Chun-Yu
authors: CY
authors: Wang
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Yan-Chao
authors: YC
authors: Li
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Chang-Jiang
authors: CJ
authors: Yu
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Yuan-Feng
authors: YF
authors: Gong
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Jun
authors: J
authors: Zhang
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Qiu-Shi
authors: QS
authors: Wang
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Bin-Lin
authors: BL
authors: Song
authors: Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia.
authors: Kuai
authors: K
authors: Yu
authors: Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia.
authors: H Criss
authors: HC
authors: Hartzell
authors: Laboratory of Cardiovascular Phenomics, Department of Pharmacology, Center for Molecular Medicine, School of Medicine University of Nevada, Reno, Nevada.
authors: Dayue Darrel
authors: DD
authors: Duan
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Dan
authors: D
authors: Zhao
authors: Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China.
authors: Zhi-Ren
authors: ZR
authors: Zhang
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D000075369:Anoctamin-1; D001145:Arrhythmias, Cardiac / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D065101:Chloride Channel Agonists / Q000494:pharmacology; D018118:Chloride Channels / Q000378:metabolism*; D004195:Disease Models, Animal; D008297:Male; D008807:Mice, Inbred BALB C; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D015427:Reperfusion Injury / Q000378:metabolism
chemical_list: C531181:ANO1 protein, mouse; D000075369:Anoctamin-1; D065101:Chloride Channel Agonists; D018118:Chloride Channels; D002118:Calcium