Proliferation of vascular smooth muscle cells (VSMCs) contributes to the development of
atherosclerosis.
Ezetimibe is a new
lipid lowering agent that inhibits
cholesterol absorption. In the present study we attempted to investigate whether
ezetimibe has any effect on VSMC proliferation and the potential mechanisms involved. Our data showed
ezetimibe abrogated the proliferation and migration of primary rat VSMCs induced by Chol:MβCD. Mechanically, we found that
ezetimibe was capable of abolishing
cyclin D1, CDK2, phospho-Rb (p-Rb), and E2F
protein expressions that were upregulated by Chol:MβCD treatment. In addition,
Ezetimibe was able to reverse cell cycle progression induced by Chol:MβCD, which was further supported by its down-regulation of
cyclin D1 promoter activity in the presence of Chol:MβCD. Furthermore,
ezetimibe abrogated the increment of phospho-ERK1/2 (p-ERK1/2) and nuclear accumulation of ERK1/2 in VSMCs induced by Chol:MβCD. Inhibition of the MAPK pathway by using ERK1/2 inhibitor
PD98059 attenuated the reduction effect of
ezetimibe on the expressions of phosphor-MEK1 (p-MEK1), p-ERK1/2, and
cyclin D1. Taken together our data suggest that
ezetimibe inhibits Chol:MβCD-induced VSMCs proliferation and leads to cell cycle arrest at the G0/G1 phase by suppressing
cyclin D1 expression via the MAPK signaling pathway. These novel findings support the potential pleiotropic effect of
ezetimibe in
cardiovascular disease.