Roscovitine Inhibits Proliferation And Migration Of VSMCs And Rat Carotid Artery Neointima Formation After Balloon Injury

Objective:Abnormal proliferation and migration of VSMCs is the major cause of in-stent restenosis. Thus, drugs interfering with proliferation and migration of VSMCs are promising candidates for antirestenotic therapy. As a CDKI, roscovitine can inhibit cell cycle of multiple cell types. We intend to observe the effect of roscovitine on cell cycle, proliferation and migration of VSMCs in vitro.Methods:Flow cytometry was used to analysis the cell cycle distribution of VSMCs and the effect of roscovitine on VSMCs cell cycle at different time points. Cell proliferation was quantified via BrdU incorporation, which is a commonly used proliferative marker. Our experiment studied the effect of roscovitine inhibiting VSMCs proliferation at different concentration and different time. Migration was measured by wound-healing assay, and wound width was used to assay the effect of roscovitine on migration of VSMCs.Results:Roscovitine arrested VSMCs in G0/G1-phase effectively and decreased the cell number in S-phase. Roscovitine inhibited BrdU incorporation of VSMCs in a concentration-dependent way. VSMCs migrating to wound and the healing of wound were inhibited by roscovitine significantly.Conclusion:Roscovitine inhibits proliferation and migration of VSMCs significantly in vitro. This may be resulted from its cell cycle inhibition and roscovitine arrested VSMCs in G0-G1 phase effectively. Therefore, roscovitine seems to be promising drug for further development in antirestenotic therapy.Objective:We intend to injure rat carotid artery via simulating operation of percutaneous transluminal coronary angioplasty and provide a stable and reliable animal experimental model for the study of restenosis therapy.Methods:We injured rat carotid artery by balloon dilation.7days,14 days and 28 days after injury, the injured segments of the carotid artery were collected respectively. We observed the histomorphometric change via H.E. staining and the proliferation ratio of vascular smooth muscle cells by immunofluorescent staining.Results:There is varying degrees of neointima formation in rat carotid artery after balloon injury. The larger intimal thickness but smaller lumen area and decreasing vascular smooth muscle cells proliferation ratio were seen with time prolonging.28 days after injury, the proliferation of vascular smooth muscle cells almost stop and there is no significant statistical difference compared with Sham group.Conclusion:The carotid artery balloon injury model in rat simulates the pathological change of neointima formation after PCI to some extend and it can be used in the in vivo study of restenosis.Objective:This part intends to observe whether roscovitine can inhibit VSMCs proliferation and neointima formation after balloon injury, so that roscovitine become a new candidate for interventional therapy.Methods:We established carotid atery balloon injury model in rat and administrated roscovitine (200μM) locally.14 days after injury, the injured segments of the artery were collected. We observed the effects of roscovitine on VSMCs proliferation using immunofluorescent staining, on neointima formation and carotid artery stenosis via H.E. staining and histomorphometric analysis.Results:14 days after balloon injury, we observed significant VSMCs proliferation and neointima formation in rat carotid artery. However, the local application of roscovitine (200μM) reduced the proliferation ratio of VSMCs and inhibited neointima formation effectively.Conclusion:The local delivery of roscovitine can decrease proliferation ratio of VSMCs and then inhibit neointima formation in rat carotid artery effectively, which reduce the incidence of restenosis.