Mechanistic investigation of adult myotube response to exercise and drug treatment in vitro using a multiplexed functional assay system.

The ability to accurately measure skeletal muscle functional performance at the single-cell level would be advantageous for exercise physiology studies and disease modeling applications. To that end, this study characterizes the functional response of individual skeletal muscle myotubes derived from adult rodent tissue to creatine treatment and chronic exercise. The observed improvements to functional performance in response to these treatments appear to correlate with alterations in hypertrophic and mitochondrial biogenesis pathways, supporting previously published in vivo and in vitro data, which highlights the role of these pathways in augmenting skeletal muscle output. The developed system represents a multiplexed functional in vitro assay capable of long-term assessment of contractile cellular outputs in real-time that is compatible with concomitant molecular biology analysis. Adoption of this system in drug toxicity and efficacy studies would improve understanding of compound activity on physical cellular outputs and provide more streamlined and predictive data for future preclinical analyses.