Protection by simvastatin on hyperglycemia-induced endothelial dysfunction through inhibiting NLRP3 inflammasomes

Recent studies have demonstrated that NLRP3 inflammasome complex acts as pivotal elements to initiate inflammatory responses and plays an important role in the dysfunction of cardiovascular complications. Meanwhile, simvastatin prevents vascular endothelial dysfunction from inflammasome invasion contributing to reduce cardiovascular risk. However, Whether or not the simvastatin improves vascular endothelial barrier function through inhibiting the activation of NLRP3 inflammasome pathway remains unknown. Here, we explored the role and mechanisms of simvastatin in the activation of NLRP3 inflammasome which are involved in vascular endothelial hyperpermeability causing by the disruption of tight junction protein ZO-1 and adherens junction protein VE-Cadherin, an early initiation of cardiovascular complication. Our results found that high glucose significantly induced the formation and activation of NLRP3 inflammasome through NADPH oxidase-dependent reactive oxygen species (ROS) formation, associated with vascular endothelial hyperpermeability causing by ZO-1 and VE-Cadherin disruption in the rat aortic endothelial cells (RAECs). Simvastatin treatment remarkably abolished vascular endothelial hyperpermeability and enhanced the protein expression of ZO-1 and VE-Cadherin through NLRP3 inflammasome. Mechanistically, the inhibitory role of simvastatin endothelial hyperpermeability is attributed to the decreased release of cytoplasmic high mobility group box protein-1 (HMGB1) derived from endothelial NLRP3 inflammasome activation. We further confirm the protective role of simvastatin on vascular leakage in the heart of diabetic rats injected with Evans blue dye, which was associated with HMGB1 release in the serum. Collectively, the mechanism of simvastatin treatment alleviating vascular endothelial permeability dysfunction may be through inhibiting the NLRP3 inflammasome-dependent HMGB1 release in RAECs.