Effect of Simvastatin Treatment on "In Vitro" NLRP1 Inflammasome Expression in Peripheral Arterial Disease.

Background: Inflammatory stress stimuli in the plasma of patients with peripheral artery disease (PAD) are able to trigger the expression of NLRP1 inflammasome in human aortic endothelial cells (HAECs). Our objective was to elucidate the effect of simvastatin treatment on NLRP1 inflammasome expression in endothelial cells exposed to the plasma of PAD patients.

Methods: The study included 81 patients with PAD, 24 of them treated with simvastatin (20 mg/day) and 57 without statin therapy. HAECs between passages 3 and 6 were stimulated for 2 hr using the plasma samples of the study participants. NLRP1 gene transcription of HAECs exposed to the plasma of PAD patients was quantificated.

Results: HAECs exposed to the plasma of PAD patients with simvastatin therapy showed significantly higher expression of the NLRP1 gene compared with those exposed to the plasma of PAD patients without this treatment (relative quantitation [RQ] 1.12 ± 0.06 vs. 1.06 ± 0.07, P = 0.03). Furthermore, HAECs exposed to the plasma of patients with critical limb ischemia and treated with simvastatin responded with a higher NLRP1 expression than those exposed to the plasma of simvastatin-treated patients with claudication (RQ 1.1 ± 0.3 vs. 0.99 ± 0.14, P < 0.001).

Conclusion: Simvastatin intake in PAD patients increases in vitro reactivity of NLRP1 inflammasome gene expression in HAECs, especially in critical limb ischemia patients.