外加直流电场对血管平滑肌细胞形态及迁移行为的影响

在外加直流电场(electricalfields,EFs)作用下血管平滑肌细胞(VSMCs)膜表面细胞生长因子受体表达发生明显的变化,并影响细胞形态、迁移的特性。通过EFs干预装置干预体外培养的大鼠主动脉VSMCs,记录和分析细胞图像,研究不同强度电场、不同作用时间下VSMCs迁移和细胞形态的变化,并用免疫细胞化学或免疫荧光染色方法检测与VSMCs迁移相关的血小板衍化生长因子受体(PDGFR)、血管紧张素II1型受体(AT1R)和2型受体(AT2R)等受体的表达情况,研究EFs影响VSMCs形态及迁移的机制。研究结果提示,在EFs干预作用下,VSMCs膜PDGFR表达增加,部分细胞呈不对称分布,在EFs阴极面较集中;细胞中AT1R表达亦增加,但无明显不对称分布现象;AT2R表达没有改变;EFs长时间作用下,培养的VSMCs有明显的电场趋化性,细胞向阴极迁移的距离明显高于无EFs作用对照组,细胞膜向阴极方向伸展,发生形状改变,定向迁移依赖于EFs强度。EFs作用下,部分细胞生长因子受体的表达上调和重分布,可能与细胞定向迁移的启动和维持有关。

The Biological Effects of Simulated Electrical Fields on the Appearance and Migration of Vascular Smooth Muscle Cells in Vitro

To study the change of some cellular growth factor receptors and their effect on the morphousand migration of vascular smooth muscle cells (VSMCs) under electrical field. An electrophoresis apparatus wasdesigned for applying the direct current electric fields to the cultured VSMCs, which got from the aorta of rat.Interval photographs were used to analyse the direction and distance of VSMCs migration. The some cellulargrowth factors such as platelet derived growth factor receptor (PDGFR), angiotensin II type 1 receptor (AT1R) andtype 2 receptor (AT2R) were studied by immunohistochemistry or immunofluorescence. And then the relationshipbetween those receptors and VSMCs migration was analyzed, including the mechanism relation to the migration ofVSMCs. Under the direct current electric field, the expression of PDGFR were increased obviously and distributedasymmetricly on the membrane of VSMCs. This receptors were mainly focus on the cathode side of cellularmembrane in electric field. The AT1R were also enhanced in the cells after exposure to the electric field, and theexpression of AT2R had showed the changeless. The longer time exposure to the 150 mV/mm electric field, themore electrotaxis the cells showed, that is the distance of cellular migration increased obviously with the timecomparing with control group. Our study indicates that: electric fields applying to the rat VSMCs can change thegrowth characteristic and increase the directly migration of VSMCs. These effects maybe relate to the up-regulatedexpression and re-distribution of some cellular growth factor receptors such as PDGFR, AT1R and AT2R.