Abstract
Recently, the prevention of cardiovascular events has become one of the most important aims of diabetes care. Peroxisome proliferator-activated receptor (PPAR) agonists have been reported to have vascular protective effects. Here, we examined whether pemafibrate, a selective PPAR alpha agonist, attenuated neointima formation after vascular injury and vascular smooth muscle cell (VSMC) proliferation. We performed endothelial denudation injury in mice treated with a high-fat diet (HFD) or normal chow. Orally administered pemafibrate significantly attenuated neointima formation after vascular injury in HFD and normal chow mice. Interestingly, pemafibrate increased the serum fibroblast growth factor 21 concentration and decreased serum insulin concentrations in HFD mice. In addition, body weight was slightly but significantly decreased by pemafibrate in HFD mice. Pemafibrate, but not bezafibrate, attenuated VSMC proliferation in vitro. The knockdown of PPAR alpha abolished the anti-VSMC proliferation effect of pemafibrate. BrdU assay results revealed that pemafibrate dose-dependently inhibited DNA synthesis in VSMCs. Flow cytometry analysis demonstrated that G1-to-S phase cell cycle transition was significantly inhibited by pemafibrate. Pemafibrate attenuated serum-induced cyclin D1 expression in VSMCs. However, apoptosis was not induced by pemafibrate as assessed by the TUNEL assay. Similar to the in vitro data, VSMC proliferation was also decreased by pemafibrate in mice. These data suggest that pemafibrate attenuates neointima formation after vascular injury and VSMC proliferation by inhibiting cell cycle progression.