HMG-CoA reductase inhibitor simvastatin inhibits proinflammatory cytokine production from murine mast cells.

Background: Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, a key rate-limiting enzyme in the mevalonate pathway. Accumulating data suggest that statins exhibit anti-inflammatory effects on a number of experimental models including experimental autoimmune encephalomyelitis and antigen-induced allergic airway inflammation. However, the mechanism underlying the anti-inflammatory effect of statins is still largely unknown. In this study, we examined the effect of a representative statin, simvastatin, on proinflammatory cytokine production from murine mast cells.

Methods: Bone marrow-derived mast cells (BMMCs) were stimulated with lipopolysaccharide (LPS) in the presence or absence of simvastatin, and TNF-alpha and IL-6 production from BMMCs was evaluated at mRNA and protein levels. The effect of simvastatin on the expression of tristetraprolin, an RNA-binding protein that promotes decay of TNF-alpha mRNA, was evaluated.

Results: Incubation of BMMCs with simvastatin resulted in the inhibition of LPS-induced TNF-alpha production at both mRNA and protein levels. Simvastatin also inhibited IL-6 production from LPS-stimulated BMMCs. However, simvastatin did not enhance the expression of tristetraprolin.

Conclusions: Simvastatin inhibits the production of TNF-alpha and IL-6 from activated mast cells in part by inhibiting de novo synthesis of their transcripts and the inhibition may account for the anti-inflammatory effect of simvastatin.