Fetal muscle extract improves muscle function and performance in aged mice.

Area of Science:

• Muscle biology and aging research
• Proteomics and molecular analysis
• Gerontology and regenerative medicine

Background:

• Sarcopenia, the loss of skeletal muscle mass and function, is a significant health issue in aging populations.
• Differential proteomic profiles in fetal muscle development may hold keys to understanding muscle growth.
• Hypothesis: Fetal muscle extract from the hypertrophy stage can mitigate age-related muscle decline.

Purpose of the Study:

• To investigate the potential of fetal sheep muscle extract (FSME) to improve muscle health in aged mice.
• To analyze the proteomic differences between fetal and adult sheep muscle extracts.
• To evaluate the effects of FSME on myoblast proliferation and in vivo muscle function in aged mice.

Main Methods:

• Skeletal muscle extracts from fetal (16-week gestation) and adult sheep were prepared.
• Isobaric tags for relative and absolute quantitation (iTRAQ) and KEGG pathway analysis identified differentially expressed proteins.
• FSME and adult sheep muscle extract (ASME) effects on human myoblast proliferation were assessed.
• Aged mice received intramuscular FSME or vehicle injections for 8 weeks, followed by grip strength and muscle force tests.
• Serum cytokine levels were analyzed using multiplex assays.

Main Results:

• iTRAQ analysis revealed significant differences in protein expression between FSME and ASME, with many proteins related to muscle development.
• FSME significantly promoted myoblast proliferation (+300%) without cytotoxicity.
• In aged mice, FSME treatment increased lean mass (+10%), grip strength (+50%), and fatigue resistance.
• Histological analysis showed no significant difference in muscle cross-sectional area between FSME and control groups.
• FSME treatment led to a significant reduction in specific circulating inflammatory cytokines, including IL-12, G-CSF, KC, and RANTES.

Conclusions:

• This study provides the first evidence of beneficial effects of fetal muscle extract on muscle health in aged mice.
• FSME demonstrates potential as a therapeutic agent for age-related muscle decline and sarcopenia.
• Further research into the active components of FSME could lead to novel sarcopenia treatments.