SFEBES2023 Poster Presentations Metabolism, Obesity and Diabetes (70 abstracts)
1Center for Health and Life Sciences, Coventry, United Kingdom. 2Institute of Biomedical and Clinical Science, Exeter, United Kingdom. 3Oxford Centre for Diabetes, Oxford, United Kingdom
Introduction: Pharmacological targeting of skeletal muscle to enhance metabolism through signalling pathways independent of insulin could be effective in treating metabolic diseases such as obesity and type 2 diabetes. BI-9774 is an allosteric agonist which has been shown to have high potency in enhancing 5 AMP-activated protein kinase (AMPK) activity. The purpose of these experiments was to establish the effects of BI-9774 on AMPK signalling and mitochondrial capacity in LHCN-M2 human skeletal muscle cells.
Methods: LHCN-M2 human skeletal muscle cells were cultured and differentiated into multinucleated myotubes. Following 10 days of differentiation, time (0-12 h) and dose response curves (0-1µnM) were conducted to establish phosphorylation of AMPK (Thr172), Acetyl-CoA carboxylase (ACC) (Ser79) and p38 MAPK Kinase (Thr180/Tyr182) in response to BI-9774.
Results: Time course experiments showed an increase in the phosphorylation of AMPK at 15, 30 and 60 minutes and phosphorylation of ACC at 30 (P= 0.006), 60 (P= 0.004), 300 (P= 0.010) minutes when stimulated with 10nM of BI-9774. Despite being described as a selective AMPK agonist, there was an increase in p38 MAPK phosphorylation at 15 minutes of stimulation at 10nM (P= 0.015). Dose response curves showed a significant increase in AMPK and ACC phosphorylation at concentrations of equal to and greater than 10nM (P<0.05) and 1nM (P<0.05), respectively. Preliminary seahorse data suggests that concentrations of BI-9774 up to 1µM induce no changes to basal or maximal oxygen consumption rates.
Conclusions: These experiments show for the first time that BI-9774 can induce phosphorylation of the AMPK-ACC and p38 MAPK signalling pathways in human skeletal muscle myotubes. Further experiments are required to investigate the effects of BI-9774 on enhancing skeletal muscle metabolism as a potential therapeutic for treating metabolic disease.