β1- and β2-adrenergic receptor stimulation differ in their effects on PGC-1α and atrogin-1/MAFbx gene expression in chick skeletal muscle

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Vol. 211; pp. 1 - 6
• Main Authors: Shimamoto, Saki, Ijiri, Daichi, Kawaguchi, Mana, Nakashima, Kazuki, Tada, Osamu, Inoue, Hiroki, Ohtsuka, Akira
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2017
• Subjects: Atrogin-1/MAFbx; Chicken; PGC-1α; Skeletal muscle; β-Adrenergic receptor; PBS; β-AR; MAFbx; PGC-1α; AKT; i.p; Chicken; Atrogin-1/MAFbx; Skeletal muscle; β-Adrenergic receptor
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/j.cbpa.2017.05.013

Adrenaline changes expression of the genes encoding peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), which is known as a regulator of muscle size, and atrogin-1/muscle atrophy F-box (MAFbx), which is a muscle-specific ubiquitin ligase. However, the subtype of β-adrenergic receptor (β-AR) involved in regulating these genes in skeletal muscle is not yet well defined. In this study, the effects of intraperitoneal injection of adrenaline and three β1–3-AR selective agonists on chick skeletal muscle metabolism were examined, to evaluate the functions of β-AR subtypes. Adrenaline decreased atrogin-1/MAFbx mRNA levels accompanied by an increase in PGC-1α mRNA and protein levels. However, among the three selective agonists, only the β1-AR agonist, dobutamine, increased PGC-1α mRNA and protein levels, while the β2-AR agonist, clenbuterol, suppressed atrogin-1/MAFbx mRNA levels. In addition, preinjection of the β1-AR antagonist, acebutolol, and the β2-AR antagonist, butoxamine, inhibited the adrenaline-induced increase in PGC-1α mRNA levels and the decrease in atrogin-1/MAFbx mRNA levels, respectively. Compared with adrenaline administration, the β3-AR agonist, BRL37344, decreased PGC-1α mRNA levels and increased atrogin-1/MAFbx mRNA levels. These results suggest that, in chick skeletal muscle, PGC-1α is induced via the β1-AR, while atrogin-1/MAFbx is suppressed via the β2-AR.