Endurance Training Inhibits the JAK2/STAT3 Pathway to Alleviate Sarcopenia.

Area of Science:

• Gerontology
• Muscle Physiology
• Molecular Biology

Background:

• Aging is characterized by a decline in skeletal muscle mass, strength, and function, a condition known as sarcopenia.
• The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway is implicated in skeletal muscle atrophy.
• Endurance training is recognized for its potential to mitigate sarcopenia, but the underlying molecular mechanisms require further elucidation.

Purpose of the Study:

• To investigate the effects of endurance training on age-related sarcopenia in mice.
• To explore the role of the JAK2/STAT3 signaling pathway in endurance training-induced improvements in sarcopenia.
• To identify potential molecular targets, such as Nuclear receptor subfamily 1, group D member 1 (Nr1d1), involved in sarcopenia modulation.

Main Methods:

• A 3-month running exercise intervention was implemented in a mouse model of aging (SAMP8 mice).
• Gene expression analysis was performed to assess the levels of JAK2/STAT3 pathway components, SOCS3, and Nr1d1.
• Phenotypic assessments evaluated muscle function, mass, and strength.

Main Results:

• Endurance training significantly improved muscle function, mass, and strength in aged mice (SAMP8).
• The expression of JAK2/STAT3 pathway factors decreased in trained mice compared to controls.
• Expression of SOCS3 and Nr1d1, an atrophy-related factor, was significantly increased following endurance training.

Conclusions:

• Endurance training effectively ameliorates sarcopenia phenotypes in aged mice.
• The JAK2/STAT3 pathway is a likely mechanism through which endurance training improves sarcopenia.
• Nr1d1 may serve as a potential molecular target in the context of endurance training and sarcopenia.