Physiological Muscle Function Is Controlled by the Skeletal Endocannabinoid System in Murine Skeletal Muscles

Area of Science:

• Muscle physiology
• Mitochondrial function
• Endocannabinoid system research

Background:

• The endocannabinoid system (ECS) regulates vital bodily functions, including muscle activity.
• The specific roles of the ECS in skeletal muscle function and disease are not fully understood.
• A skeletal muscle-specific CB1 receptor knockdown (skmCB1-KD) mouse model was previously established.

Purpose of the Study:

• To elucidate the mechanisms underlying reduced muscle force generation in skmCB1-KD mice.
• To investigate the impact of CB1 receptor knockdown on calcium dynamics and mitochondrial respiration in skeletal muscle.

Main Methods:

• Analysis of calcium dynamics post-electrical stimulation-induced fatigue.
• Assessment of store-operated calcium entry (SOCE).
• Functional analysis of mitochondrial respiration.

Main Results:

• Reduced muscle performance in skmCB1-KD mice is linked to altered mitochondrial ATP production.
• A significant decrease in respiratory chain complex IV was observed.
• Slower dissipation of mitochondrial membrane potential was noted upon FCCP addition.

Conclusions:

• Altered mitochondrial ATP production contributes to impaired muscle performance in skmCB1-KD mice.
• Defects in mitochondrial respiration, specifically complex IV, are implicated in ECS-mediated muscle function.