Irisin ameliorates age-associated sarcopenia and metabolic dysfunction

Area of Science:

• Gerontology
• Molecular Biology
• Metabolic Physiology

Background:

• Age-associated sarcopenia involves progressive loss of skeletal muscle mass, strength, and function.
• Aging is frequently accompanied by metabolic dysfunctions, impacting overall health.
• Irisin, a myokine derived from FNDC5, is linked to exercise-induced health benefits.

Purpose of the Study:

• To investigate changes in FNDC5/irisin expression in skeletal muscle during aging.
• To determine if irisin administration can counteract age-related sarcopenia and metabolic decline.

Main Methods:

• Quantitative real-time PCR and western blotting analyzed FNDC5/irisin levels in young and aged mice.
• FNDC5/irisin knockout mice were used to assess the impact of its deficiency on aging.
• Recombinant irisin was administered to aging mice to evaluate therapeutic effects on sarcopenia and metabolic parameters.

Main Results:

• FNDC5/irisin expression decreased in aged mice, and its deficiency exacerbated muscle atrophy and molecular changes.
• Irisin treatment improved muscle strength, mass, fiber size, and molecular phenotypes in aging mice.
• Irisin administration alleviated age-associated fat tissue expansion, insulin resistance, and hepatic steatosis.

Conclusions:

• Irisin plays a crucial role in maintaining muscle physiology and systemic energy homeostasis during aging.
• Irisin administration presents a potential therapeutic strategy for combating age-related sarcopenia and metabolic diseases.