Effects And Mechanisms Of Breviscapin On Migration Of VSMCs Cultured Under Hyperglycemic Conditions

Aim:To investigate the effects and mechanisms of breviscapin on migration of VSMC cultured in a high-glucose mediumMethods:(1) In vivo. Diabetes was induced by a single dose of streptozocin (STZ,50mg/kg i.p.). Male Sprague-Dawley rats(300-350g) were separated into four groups, the sham operation group, the operation group, the STZ treated group, the STZ and breviscapin treated group. Vehicle or breviscapin (20mg/kg) was administered daily beginning one day prior to balloon injury and lasting until28days after the injury. Carotid artery bolloon injury was performed by introducing a2F catheter through an external carotid arteriotomy incision to the aortic arch to gentlely scrape off the endomembrane.28days after balloon injury, the common carotid arteries were excised bilaterally, fixed, and embedded paraffin. Paraffin-embeded tissue were stained with hematoxylin-eosin. Morphometric analysis was perfromed and neointimal fromation was expressed as the percentage of intima of media and intima ([intima/media+intima]×100(%)).(2) In vitro. Rat VSMCs were isolated from the thoracic aorta of Sprague-Dawley. More than95%of the cells were posiitive fora-actin and exhibited the typical hill-and-valley morphology of VSMCS. In this study, cell passages between four and ten were used. Synchonized cells were treated with breviscapin or other agents for1hour prior to high glucose stimulation. High glucose (25mmol/L) was applied to VSMCs for24h in the wound healing assay and10min for analysis of ERK and MLCK activation. Wound healing assay was used to assay cell migration while western blot was used to analyze ERK and MLCK activation.Results:In the rat carotid atery balloon injury model, breviscapin treatment showed a significant effect on the prevention of neointimal formation compared with vehicle treated diabetic rats. In cultured VSMCs, breviscapin siganificantly attenuated high-glucose induced migration measured by wound healing assay. Furthermore, breviscapin inhibited high-glucose stimulated ERK and MLCK phosphorylation.Conclusions:Breviscapin prevented both injury-induced neointimal formation in vivo and high glucose-induced VSMCs migration in virto through its inhibiton effect on ERK1/2-MLCK pathway, suggesting breviscapin may be a promising agent to prevent restenosis following angioplasty.