Cardiovascular disease is recognized as a leading cause of death worldwide, but the risk of death is 2-3 times higher for individuals with diabetes. NLRP3 inflammasome activation is a leading pathway of vascular damage, and new treatment methods are needed to reduce NLRP3 inflammasome expression, along with a detailed understanding of how those treatments work. In a series of assays on human vascular endothelial cells that were exposed to high concentrations of free fatty acids (FFA) to induce a diabetes-like environment, we found a significant impact of cilostazol, a vasodilator widely used to treat blood flow problems and well-tolerated medication. To our knowledge, this study is the first to demonstrate the effects of cilostazol in primary human aortic endothelial cells. We found that cilostazol significantly reduced NLRP3 inflammasome activation, as well as the activity of other related and harmful factors, including oxidative stress, expression of NADPH oxidase 4 (NOX-4), thioredoxin-interacting protein (TxNIP), high mobility group box 1 (HMGB-1), interleukin 1β (IL-1β) and IL-18. Cilostazol also protected the functionality of sirtuin 1 (SIRT1), which serves to restrict NLRP3 inflammasome activity, when exposure to FFAs would have otherwise impaired its function. Thus, it appears that cilostazol's mechanism of action in reducing NLRP3 inflammasome activation is an indirect one; it protects SIRT1, which then allows SIRT1 to perform its regulatory job. Cilostazol has potential as an already-available, well-tolerated preventive medication that may alleviate some of the adverse vascular effects of living with diabetes. The findings of the present study lay the groundwork for further research on the potential of cilostazol as a safe and effective treatment against diabetic endothelial dysfunction and vacular disease.
Keywords: NLRP3 inflammasome; SIRT1; TxNIP; atherosclerosis; cilostazol; endothelial dysfunction; free fatty acid (FFA).