MicroRNA-206 improves alcohol-mediated decreased myoblast differentiation

Abstract

Background: With recent advances in antiretroviral therapy (ART), people living with HIV (PLWH) have a near-normal life expectancy but have higher risk for aging-related comorbidities, such as metabolic disorders and frailty earlier in life than the general population. At-risk alcohol use is twice as likely in PLWH compared to the general population and alcohol-related myopathy occurs in 40- 60% of people with alcohol use disorder. Previous studies demonstrated that in vivo chronic binge alcohol (CBA) administration in simian immunodeficiency virus (SIV)-infected male rhesus macaques decreased myoblast differentiation and downregulated microRNA-206 (miR-206) expression in skeletal muscle. We hypothesized that increasing miR-206 expression would increase differentiation in CBA-derived primary macaque myoblasts. Methods: Eight SIV-infected female rhesus macaques received either water (VEH) or CBA (13- 14 g/kg/week) for 14.5 months. Three months into either VEH or CBA administration, animals were vaginally infected with SIVmac251, and ART was started 2.5 months later. Animals were sacrificed after 9 months, and primary myoblasts isolated from vastus lateralis muscle 24 hours after the last dose of alcohol (blood alcohol=0 mM). Myoblasts at passage 4 (VEH & CBA) were proliferated for three days. Cells were then transfected with either miR-206 mimic or control (miR scramble). Four experimental groups were studied at day 5 of differentiation: VEH+scramble, CBA+scramble, VEH+miR-206, and CBA+miR-206. Expression of miR-206 was determined by qPCR. Myoblast differentiation was determined by myotube density, calculated as the average number of myotubes per frame, and fusion index calculated as the percentage of myonuclei that fused into myotubes. Results: In non-transfected CBA-derived cells, myotube density and miR-206 expression was lower compared to VEH-derived myotubes (p<0.001 and p<0.05, respectively). miR-206 transfection resulted in over 150-fold higher miR-206 expression compared to VEH-scramble (p<0.05) in CBA- and VEH-derived cells. miR-206 overexpression significantly increased myotube fusion index (p<0.05) compared to myoblasts transfected with miR scramble in CBA-derived cells. Conclusions: Data show significant improvement of alcohol-mediated decreased myoblast differentiation with miR-206 overexpression. These findings suggest that increasing muscle miR-206 can potentially be used as a therapeutic strategy to improve regenerative capacity in response to muscle injury or atrophy. (Supported by: T35AA021097, F30AA029358, P60AA009803, K01AA024494) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.