Going nuclear: Molecular adaptations to exercise mediated by myonuclei

Area of Science:

• Muscle physiology
• Molecular biology
• Exercise science

Background:

• Muscle fibers are multinucleated cells with peripherally located nuclei (myonuclei).
• Myonuclei are crucial for regulating muscle homeostasis and gene transcription, especially during exercise.
• Recent advancements enable high-resolution analysis of myonuclei responses to exercise stimuli in vivo.

Purpose of the Study:

• To review how myonuclei modulate their transcriptome, epigenetic status, mobility, shape, and microRNA expression in response to exercise in vivo.
• To identify current knowledge gaps regarding myonucleus-specific contributions to exercise adaptation.
• To provide perspectives on future research directions in this field.

Main Methods:

• This review synthesizes recent high-resolution molecular and cellular findings on myonuclei.
• Focuses on studies investigating exercise-induced changes in myonuclei in vivo.
• Integrates data on gene transcription, epigenetics, nuclear morphology, and microRNA expression.

Main Results:

• Myonuclei exhibit dynamic changes in gene transcription, epigenetic modifications, and microRNA profiles following exercise.
• Nuclear shape and mobility are altered in response to exercise stimuli.
• These adaptations are critical for muscle plasticity and repair.

Conclusions:

• Myonuclei play a pivotal role in exercise-induced muscle adaptation through complex molecular and cellular changes.
• Further research is needed to fully elucidate the high-fidelity, myonucleus-specific mechanisms underlying these adaptations.
• Understanding these processes can inform strategies for enhancing muscle health and performance.