ExermiR-129-3p Enhances Muscle Function by Improving Mitochondrial Activity Through PARP1 Inhibition

Area of Science:

• Molecular Biology
• Exercise Physiology
• Mitochondrial Biology

Background:

• Physical exercise positively impacts skeletal muscle health.
• Limitations in exercise capacity necessitate alternative strategies to maintain muscle function.
• Identifying molecular mediators of exercise is crucial for developing therapeutic interventions.

Purpose of the Study:

• To identify molecular mediators of exercise that can improve skeletal muscle function.
• To investigate the role of microRNA-129-3p (miR-129-3p) in exercise-induced muscle adaptations.
• To elucidate the effects of miR-129-3p on mitochondrial activity and related signaling pathways.

Main Methods:

• Analysis of miR-129-3p expression in skeletal muscle post-exercise.
• Investigation of miR-129-3p's downstream effects on the PARP1-SIRT1-PGC1α pathway.
• Functional studies involving muscle-specific miR-129-3p overexpression in mice and AAV9 delivery in obese mice.

Main Results:

• Exercise upregulated miR-129-3p, which directly inhibits the NAD+-consuming enzyme PARP1.
• miR-129-3p increased NAD+ levels, activating SIRT1 and enhancing mitochondrial function by reducing PGC1α acetylation.
• Overexpression of miR-129-3p significantly improved exercise capacity and muscle strength in mice, including obese models.

Conclusions:

• miR-129-3p, induced by exercise, effectively mimics the beneficial effects of physical activity on skeletal muscle.
• miR-129-3p represents a promising therapeutic target for enhancing muscle health.
• This microRNA holds potential for individuals unable to participate in physical exercise.