한빛사 논문
Jihee Kima,1, Chad A. Grotegutb,1, James W. Wislera, Lan Maoc, Paul B. Rosenberga, Howard A. Rockmana,d,e, and Robert J. Lefkowitza,f,g,2
aDepartment of Medicine, Duke University Medical Center, Durham, NC 27710; bDepartment of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC 27710; cDepartment of Medicine, Division of Cardiology and Duke Cardiovascular Physiology Core, Duke University Medical Center, Durham, NC 27710; dDepartment of Cell Biology, Duke University Medical Center, Durham, NC 27710; eDepartment of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710; fDepartment of Biochemistry, Duke University Medical Center, Durham, NC 27710; and gHoward Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710
1J.K. and C.A.G. contributed equally to this work.
2To whom correspondence may be addressed.
Abstract
A decrease in skeletal muscle strength and functional exercise capacity due to aging, frailty, and muscle wasting poses major unmet clinical needs. These conditions are associated with numerous adverse clinical outcomes including falls, fractures, and increased hospitalization. Clenbuterol, a β2-adrenergic receptor (β2AR) agonist enhances skeletal muscle strength and hypertrophy; however, its clinical utility is limited by side effects such as cardiac arrhythmias mediated by G protein signaling. We recently reported that clenbuterol-induced increases in contractility and skeletal muscle hypertrophy were lost in β-arrestin 1 knockout mice, implying that arrestins, multifunctional adapter and signaling proteins, play a vital role in mediating the skeletal muscle effects of β2AR agonists. Carvedilol, classically defined as a βAR antagonist, is widely used for the treatment of chronic systolic heart failure and hypertension, and has been demonstrated to function as a β-arrestin-biased ligand for the β2AR, stimulating β-arrestin-dependent but not G protein-dependent signaling. In this study, we investigated whether treatment with carvedilol could enhance skeletal muscle strength via β-arrestin-dependent pathways. In a murine model, we demonstrate chronic treatment with carvedilol, but not other β-blockers, indeed enhances contractile force in skeletal muscle and this is mediated by β-arrestin 1. Interestingly, carvedilol enhanced skeletal muscle contractility despite a lack of effect on skeletal muscle hypertrophy. Our findings suggest a potential unique clinical role of carvedilol to stimulate skeletal muscle contractility while avoiding the adverse effects with βAR agonists. This distinctive signaling profile could present an innovative approach to treating sarcopenia, frailty, and secondary muscle wasting.
adrenergic receptor, β-arrestin, β-blocker, carvedilol, skeletal muscle contractility
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