Cardiac β-Adrenoceptor Signaling: The New Insight on An Old Target in the Therapy of Cardiovascular Disease

Review Cardiac β-Adrenoceptor Signaling: The New Insight on An Old Target in the Therapy of Cardiovascular Disease Ying Song 1, Anthony Yiu-Ho Woo 2,*, Yan Zhang 3,4,*, and Ruiping Xiao 5,6,7,8 1 Center of Basic Medical Research, Institute of Medical Innovation and Research, Peking University Third Hospital, Beijing, 100191, China. 2 School of Life Sciences and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, China. 3 Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, School of Basic Medical Sciences, Ministry of Education, Peking University Health Science Center, Beijing, 100191, China. 4 Beijing Key Laboratory of Cardiovascular Receptors Research, Peking University, Beijing, 100191, China. 5 State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China. 6 Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China. 7 Beijing City Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, 100871, China. 8 PKU-Nanjing Joint Institute of Translational Medicine, Nanjing, 210000, China. * Correspondence: yiuhowoo@syphu.edu.cn (Anthony Yiu-Ho Woo), Tel.: +86-24-23986375; zhangyan9876@pku.edu.cn (Yan Zhang), Tel.: +86-10-82805945.     Received: 19 October 2022 Accepted: 28 October 2022 Published: 21 December 2022   Abstract: A variety of G protein-coupled receptors (GPCRs) are involved in the regulation of cardiovascular function. The β-adrenoceptors (β-ARs), with three subtypes, are the dominant receptor species in the heart, in which the β1-AR and the β2-AR are considered functional. Stimulation of the β-ARs produces myocardial inotropy via activation of the Gs-cAMP-PKA signaling cascade. Prolonged stimulation of the β1-AR is cardiac harmful because the stimulated β1-AR couples only to Gs proteins and it mediates a cardiotoxic signal. On the other hand, the β2-AR couples dually to both Gs and Gi proteins and the β2-AR-Gi pathway is antiapoptotic. The activated Gi signal also counteracts the β-AR-Gs-promoted positive inotropic effect. Other key players in cardiac β-AR signaling include Ca2+/calmodulin-dependent protein kinases (CaMKs), GPCR kinases (GRKs), β-arrestins and phosphodiesterases. During heart failure, excessive sympathetic stimulation results in the activation of the cardiotoxic β1-AR-CaMKIIδ pathway and the upregulation of GRK2 and Gi in the heart. GRK2 promotes the desensitization of β-ARs and enhances a β2-AR-mediated Gi signaling. These signal transduction processes accompanying the downregulation of the β1-AR are involved in cardiac dysfunction, maladaptive cardiac remodeling, and the progression of chronic heart failure. β-Blockers are widely used in the treatment of cardiovascular disease. They have established their position as one of the “four pillars of heart failure” thirty years ago. In the present review, we provide an overview of the recent progress in the basic research of GPCRs focusing on cardiac β-AR signal transduction.