Correlation between focal adhesion kinase phosphorylation and intimal hyperplasia following vascular denudation .in rats

Cuiyu BAO; Fangzhou CHENG; Jun KE

ABSTRACT

BACKGROUND:

Focal adhesion kinase (FAK) phosphorylation influences the proliferation, migration and apoptosis of cells. However, there are no reports about the role of FAK phosphorylation in migration and proliferation of vascular smooth muscle cells during the process of vascular restenosis.

OBJECTIVE:

To analyze the correlation between FAK phosphorylation and vascular remodeling after balloon endothelial denudation in rats.

DESIGN:

Random controlled experiments in animals.

SETTING:

Cardiology Institute of Xianning College; Shenzhen Center for Chronic Disease Prevention and Control;Department of Cardiology at the Affiliated Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology.MATERrALS The experiment was carried out in the Laboratory of Cardiology at the Affiliated Tongji Hospital from March to May in 2005. Forty male Wistar rats were used in the study, and they were managed according to the ethical standard of animals.

METHODS:

①Forty rats were randomized into five groups (n =8) non-balloon endothelial denudation control group, and 4-day, 8-day, 16-day and 24-day model groups after balloon endothelial denudation. ②The rat models of restenosis following balloon endothelial denudation were built. At days 4, 8, 16 and 24 postoperatively, the denudated vessels were harvested for the detection of the morphological changes, which were taken as the judgment of successful models;Western blot method was used to detect the expression and activity of FAK. Abdominal aorta of left common carotid in rats was served as controls.MAIN OUTCOME

MEASURES:

The expressions of FAK and phosphorylation FAK in rat artery.

RESULTS:

Totally 40 rats were all involved in the result analysis.①A small quantity of FAK without phosphorylation could be detected in the controlled rats. Compared with the control group, the expression and activity of FAK in the model group rapidly increased at 4 days after balloon injury (P ＜ 0.05), and they changed in a similar manner with the increase of injury duration. The expression of FAK reached a peak at 8 days and began to descend at 16 days. The expression of phosphorylation FAK reached a peak at 16 days and then rapidly descended. ②Focal hyperplasia of intima was found at 8 days after balloon endothelial denudation, and diffuse hyperplasia of intima was found at 16-24 days after denudation.

CONCLUSION:

FAK can take part in vascular remodeling after balloon endothelial denudation in rats. The level of intimal hyperplasia is closely associated with the level of FAK and FAK phosphorylation.