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The Effects of Aging on the Intramuscular Connective Tissue
Caterina Fede1, Chenglei Fan1, Carmelo Pirri1
1Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy.
International Journal of Molecular Sciences
|October 14, 2022
Summary
Aging increases muscle stiffness by altering connective tissue. Collagen I accumulates, while elastic fibers and hyaluronan decrease, reducing muscle adaptability.
Area of Science:
- Muscle physiology
- Connective tissue biology
- Aging research
Background:
- Intramuscular connective tissue is vital for muscle structure and mechanical support.
- Age-related changes in connective tissue can lead to muscle stiffness and functional decline.
Purpose of the Study:
- To investigate age-related changes in the extracellular matrix of skeletal muscles.
- To evaluate the impact of aging on collagen, glycosaminoglycans, and elastic fibers in human and mouse muscles.
Main Methods:
- Histological analyses including Picrosirius red, Alcian blue, and Weigert Van Gieson staining.
- Immunohistochemistry to assess collagen I, collagen III, and hyaluronan.
- Comparative analysis in human quadriceps femoris and mouse hindlimb muscles across different age groups.
Main Results:
- Aging significantly increased collagen percentage, primarily due to collagen I, in both humans and mice.
- Elderly men showed reduced elastic fibers in the perimysium.
- Hyaluronan content decreased with age in both species, with no significant gender differences observed.
Conclusions:
- Increased collagen I and reduced hyaluronan and elastic fibers with aging contribute to muscle stiffening.
- These matrix alterations may impair skeletal muscle adaptability and function.
- Findings highlight the role of extracellular matrix remodeling in age-related muscle dysfunction.
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