Dysfunctional endocannabinoid CB1 receptor expression and signaling contribute to skeletal muscle cell toxicity...

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Statins are widely used lipid-lowering drugs.
• Muscular toxicity is a rare but significant side effect of statin use.
• The endocannabinoid system (ECS) plays a role in various physiological processes, including muscle function.

Purpose of the Study:

• To investigate the role of the ECS in simvastatin-induced muscle toxicity.
• To identify molecular mechanisms underlying statin-induced myopathy.

Main Methods:

• Exposure of murine C2C12 myoblasts and primary human myoblasts to simvastatin.
• Analysis of endocannabinoid levels (AEA, 2-AG) and CB1 receptor gene expression.
• Treatment with CB1 receptor antagonists (Rimonabant) and agonists (ACEA, GAT211).
• Transfection with antagomiR152 to inhibit miR-152.
• Assessment of PKC and ERK signaling pathways.

Main Results:

• Simvastatin increased AEA, 2-AG, and miR-152 levels in myoblasts.
• CB1 receptor antagonist Rimonabant exacerbated simvastatin toxicity.
• Inhibition of miR-152 partially prevented simvastatin-induced toxicity and restored CB1 function.
• Simvastatin suppressed PKC and ERK signaling pathways, downstream of CB1.
• Similar effects were observed in mouse and human skeletal muscle cells.

Conclusions:

• Dysregulation of the endocannabinoid CB1 receptor is a novel pathological mechanism in statin-induced myopathy.
• Impairment of CB1 downstream signaling pathways contributes to simvastatin toxicity.
• Targeting the ECS may offer therapeutic strategies for statin-induced muscle side effects.