“The endocannabinoid system (ECS) is known to regulate crucial bodily functions, including healthy muscle activity. However, its precise roles in normal skeletal muscle function and the development of muscle disorders remain unclear. Previously, we developed a tamoxifen-inducible, skeletal muscle-specific CB1 receptor knockdown (skmCB1-KD) mouse model using the Cre/LoxP system.
In this study, we aimed to clarify the mechanisms behind the observed reduction in muscle force generation in these mice. To investigate this, we analyzed calcium dynamics following electrical stimulation-induced muscle fatigue, assessed store-operated calcium entry (SOCE), and performed functional analysis of mitochondrial respiration.
Our findings suggest that the reduced muscle performance observed in vivo likely arises from interconnected alterations in ATP production by mitochondria. Moreover, in skmCB1-KD mice, we detected a significant decrease in a component of the respiratory chain (complex IV) and a slowed dissipation of mitochondrial membrane potential upon the addition of an un-coupler (FCCP).”
https://pubmed.ncbi.nlm.nih.gov/40508098/
“To develop effective therapies for conditions with defective endocannabinoid system (ECS) activity, it is essential to understand the skeletal ECS’s function in health and disease. Here, we present a detailed functional and molecular characterization of a transgenic mouse model with skeletal muscle-specific Cnr1 genetic ablation.
Our in vivo results demonstrate that CB1R knockdown impairs motor coordination and grip strength in mice. Furthermore, at the cellular level, we observed modestly altered calcium homeostasis and significantly decreased mitochondrial function (decreased complex IV activity). Therefore, we propose that the ECS (particularly CB1R) plays a key role in physiological muscle force generation and in maintaining cellular and mitochondrial homeostasis and function.”