Physiological and functional characterization for high-throughput optogenetic skeletal muscle exercise assays.

Area of Science:

• Biomedical Engineering
• Skeletal Muscle Physiology
• Molecular Biology

Background:

• Skeletal muscle function is crucial for human mobility and overall health.
• In vitro models of engineered muscle are valuable for studying exercise adaptation.
• Optogenetic stimulation offers a novel, less invasive method for muscle research compared to electrical stimulation.

Purpose of the Study:

• To develop and validate a high-throughput platform for in vitro exercise studies using optical stimulation.
• To investigate the effects of varying optical exercise parameters on skeletal muscle.
• To map transcriptional changes in muscle in response to optical exercise regimens.

Main Methods:

• Developed a high-throughput muscle culture system.
• Implemented an optical exercise protocol using optogenetic stimulation.
• Characterized optical rheobase for 2D muscle monolayers.
• Utilized RNA sequencing to analyze gene expression changes.

Main Results:

• Identified low optical intensities (5 μW/mm²) sufficient for functional muscle contraction.
• Mapped gene expression alterations in response to different optical exercise parameters.
• Observed impacts on myogenic, physiological, and pathological transcriptional pathways.

Conclusions:

• The developed platform enables scalable, high-throughput in vitro exercise studies.
• Optical stimulation is an effective method for inducing muscle contraction and transcriptional changes.
• This work provides a foundation for further research into skeletal muscle adaptation to exercise.