Duanyang Xie1, Li Geng2, Shuo Wang2, Ke Xiong2, Tingting Zhao2, Guanghua Wang2, Zhiqiang Feng2, Fei Lv2, Cheng Wang2, Dandan Liang3, Dan Shi3, Xiue Ma3, Yi Liu3, Jian Yang2, Chao Zhang4, Yi-Han Chen5. 1. Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China. 2. Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China. 3. Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Institute of Medical Genetics, Tongji University, Shanghai, China. 4. Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China. Electronic address: zhangchao@tongji.edu.cn. 5. Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China; Institute of Medical Genetics, Tongji University, Shanghai, China. Electronic address: yihanchen@tongji.edu.cn.
Abstract
BACKGROUND: Atrial fibrillation (AF), the most common sustained arrhythmia, significantly increases cardiovascular and cerebrovascular morbidity and mortality. The pathogenesis and treatment of AF remain a major challenge in the field of cardiology. We previously found that cold-inducible RNA-binding protein (CIRP) regulated ventricular repolarization by posttranscriptionally regulating Kv4.2/4.3 ion channels in rats, but the role of CIRP in AF is not clear. OBJECTIVE: The purpose of this study was to confirm that CIRP participates in atrial electrophysiological remodeling and AF occurrence by regulating atrial channels posttranscriptionally. METHODS: Programmed intra-atrial stimulation was used to induce AF in wild-type or transcription activator-like effector nucleases-based CIRP knockout (KO) rats. Atrial optical mapping, patch clamp, Western blotting, RNA immunoprecipitation, and luciferase reporter assays were performed to evaluate the underlying mechanism of atrial electrical remodeling. RESULTS: First, we observed a shortened atrial effective refractory period and increased susceptibility to AF in CIRP KO rats. Second, atria-specific CIRP delivery through an adeno-associated viral vector serotype 9 prolonged the atrial effective refractory period and attenuated AF development in CIRP KO rats. Third, we observed the shortened action potential duration and enhanced expression of Kv1.5 and Kv4.2/4.3 in KO rats. The transient outward current blocker 4-Aminopyridine and ultrarapid component of the delayed rectifier current blocker Diphenyl phosphine oxide-1 restored the shortened action potential duration in KO atria. Finally, we demonstrated that CIRP suppressed Kv1.5 and Kv4.2/4.3 expression by directly targeting their 3'-untranslated regions. CONCLUSION: CIRP plays a protective role in preventing AF onset through the posttranscriptional regulation of Kv1.5 and Kv4.2/4.3.
BACKGROUND:Atrial fibrillation (AF), the most common sustained arrhythmia, significantly increases cardiovascular and cerebrovascular morbidity and mortality. The pathogenesis and treatment of AF remain a major challenge in the field of cardiology. We previously found that cold-inducible RNA-binding protein (CIRP) regulated ventricular repolarization by posttranscriptionally regulating Kv4.2/4.3 ion channels in rats, but the role of CIRP in AF is not clear. OBJECTIVE: The purpose of this study was to confirm that CIRP participates in atrial electrophysiological remodeling and AF occurrence by regulating atrial channels posttranscriptionally. METHODS: Programmed intra-atrial stimulation was used to induce AF in wild-type or transcription activator-like effector nucleases-based CIRP knockout (KO) rats. Atrial optical mapping, patch clamp, Western blotting, RNA immunoprecipitation, and luciferase reporter assays were performed to evaluate the underlying mechanism of atrial electrical remodeling. RESULTS: First, we observed a shortened atrial effective refractory period and increased susceptibility to AF in CIRP KO rats. Second, atria-specific CIRP delivery through an adeno-associated viral vector serotype 9 prolonged the atrial effective refractory period and attenuated AF development in CIRP KO rats. Third, we observed the shortened action potential duration and enhanced expression of Kv1.5 and Kv4.2/4.3 in KO rats. The transient outward current blocker 4-Aminopyridine and ultrarapid component of the delayed rectifier current blocker Diphenyl phosphine oxide-1 restored the shortened action potential duration in KO atria. Finally, we demonstrated that CIRP suppressed Kv1.5 and Kv4.2/4.3 expression by directly targeting their 3'-untranslated regions. CONCLUSION:CIRP plays a protective role in preventing AF onset through the posttranscriptional regulation of Kv1.5 and Kv4.2/4.3.