大鼠后肢侧支动脉生成过程中整合素α5β1和纤维连接蛋白的表达

Expression of integrin α5β1 and fibronectin during collateral arteriogenesis in rat hindlimb

目的:探讨侧支动脉生成过程中平滑肌细胞(smooth muscle cells,SMC)移动增殖的机制。方法:结扎大鼠股动脉,应用免疫荧光组织化学技术检测侧支血管中整合素α5β1、纤维连接蛋白(fibronectin,FN)和层粘连蛋白(laminin,LN)的表达。并在体外实验中检测了不同的细胞外基质对SMC表达整合素α5β1的影响。结果:侧支血管整合素α5β1和FN的表达分别是对照侧的1.9倍和2倍;而LN的表达是对照侧的1／3。种植在FN上的SMC高表达整合素α5β1;种植在LN上的表达较低;而种植在三维Matrigel基膜成分胶里的SMC几乎不表达整合素α5β1。结论:在侧支血管发育过程中,整合素α5β1、FN和LN的表达变化,有助于侧支血管生长发育过程中SMC的迁移和增殖。

Objective： To study the mechanism responsible for migration and proliferation of smooth muscle cells during arteriogenesis. Methods： Rat femoral artery ligation was performed with knot under anaesthesia. The expression of integrin α5β1, fibronectin （FN） and Laminin （LN） in collateral vessels was studied by confocal immunofluorescence. To examine the effects of different extracellular matrix on expression of integrin α5β1 by smooth muscle cells （SMC）. SMC were cultured on different substrates： FN, LN and Matrigel. Results： Expression of integrin α5β1 and FN was 1.9-fold and 2-fold higher in collateral vessels than those in control vessels respectively. A significantly decreased expression of LN was found in growing collateral vessel, 3.2-fold lower than that in control vessels. SMCs in vitro cultured on FN expressed high levels of integrin α5β1, While on LN substrate, SMCs expressed moderate integrin α5β1. Inside Matrigel, SMCs expressed little integrin α5β1. Conclusion： The expression profiles of integrin α5β1, FN and LN in collateral vessels facilitate the migration and proliferation of SMCs during arteriogenesis.