Physical Exercise and Mitochondrial Disease: Insights From a Mouse Model.

Area of Science:

• Neurology
• Exercise Physiology
• Mitochondrial Biology

Background:

• Mitochondrial diseases (MD) are common neuromuscular disorders with no cure.
• The Harlequin (Hq) mouse model exhibits respiratory chain complex I deficiency, mirroring human MD clinical features.

Purpose of the Study:

• To investigate the effects of a combined aerobic and resistance exercise training program on the Hq mouse model of MD.
• To assess the impact of exercise on aerobic fitness, muscle strength, and molecular pathways related to mitochondrial biogenesis and anabolism.

Main Methods:

• Male Hq mice were divided into exercise and sedentary control groups.
• The exercise group underwent an 8-week combined aerobic and resistance training program.
• Muscle biochemical analyses assessed mTOR activation, PGC-1α levels, respiratory chain complex activity, and antioxidant enzymes.

Main Results:

• Exercise training significantly improved aerobic fitness and muscle strength in Hq mice compared to controls.
• Mice in the exercise group showed increased levels of phosphorylated S6 kinase beta-1 and PGC-1α.
• Enhanced activity of respiratory chain complexes I, III, and V was observed in exercised mice, alongside reduced catalase levels.

Conclusions:

• Combined exercise training is beneficial for improving physical function in a mouse model of mitochondrial disease.
• Exercise positively influences signaling pathways involved in muscle mitochondrial biogenesis and anabolism.
• The intervention demonstrated mild improvements in oxidative phosphorylation complex activity and muscle redox status.