3D Mitochondrial Structure in Aging Human Skeletal Muscle: Insights Into MFN-2-Mediated Changes.
Estevão Scudese1,2,3, Andrea G Marshall1, Zer Vue1
1Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
Aging Cell
|April 26, 2025
Summary
Aging alters mitochondrial structure in skeletal muscle, leading to dysfunction. Exercise can reverse these age-related changes by modulating mitofusin 2, preserving muscle health.
Area of Science:
- Cell Biology
- Gerontology
- Muscle Physiology
Background:
- Sarcopenia, age-related muscle loss, involves mitochondrial dysfunction.
- The impact of mitochondrial structure on aging muscle remains unclear.
- Exercise mitigates sarcopenia, but mechanisms are poorly understood.
Purpose of the Study:
- To investigate how aging affects mitochondrial 3D structure and its regulators in skeletal muscle.
- To determine if exercise can ameliorate age-related mitochondrial structural changes.
- To explore the role of mitochondrial dynamics proteins in muscle aging.
Main Methods:
- Serial block-face scanning electron microscopy (SBF-SEM) for 3D mitochondrial reconstruction.
- Analysis of mitochondrial structure, exercise capacity, and immune markers in human cohorts.
- Investigated the role of mitofusin 2 (MFN2) in mitochondrial integrity and conserved pathways in Drosophila.
Main Results:
- Aging mitochondria exhibit reduced sphericity and increased complexity, suggesting impaired contact site capacity.
- Aged skeletal muscle shows larger mitochondrial volume and decreased muscle area and exercise capacity.
- Exercise restored MFN2 levels, essential for mitochondrial structure, and this pathway is evolutionarily conserved.
Conclusions:
- Aging induces significant structural remodeling of mitochondria in skeletal muscle.
- Exercise intervention can counteract age-related mitochondrial structural decline via MFN2 modulation.
- MFN2 plays a critical role in maintaining mitochondrial integrity during aging.
