The effect of metformin on autophagy by LC3 expression in Type 2 Diabetes Mellitus (T2DM) human skeletal muscle cell culture

Background: Skeletal muscle is an essential tissue in glucose metabolism. Reduced autophagic capacity to remove damaged contractile proteins in skeletal muscle cells will contribute to the loss of muscle mass. Metformin is the first-line agent for treating type 2 diabetes mellitus (T2DM) patients. This study aims to investigate the effects of metformin on autophagy through LC3 expression in human skeletal muscle cell culture (SkMC). Methods: The T2DM human SkMC was obtained from T2DM treatment naïve patients, purchased from AcceGen Biotech®. Fully differentiated myotubes were randomized into the control and treatment groups. The treatment group was given Metformin in three doses (1 mM, 2 mM, and 3 mM). An immunoblotting assay of AMPKα and LC3 was performed using electrochemiluminescence (ECL). The quantitative expression of AMPKα and LC3 were measured at baseline, after 24-hour, 48-hour, and 72-hour. Data were analyzed using SPSS version 22 for Windows. Results: AMPKα and LC3 expression were higher in the treatment group compared to the control group. The levels of AMPKα and LC3 expression in the treatment group increased dose-dependent. Linear regression analysis demonstrated a significant correlation between metformin administration and LC3 expression levels (p<0.0001). Conclusion: Metformin administration on T2DM human SkMC resulted in increased autophagic activity, marked by increased LC3 expression.