血小板源性生长因子影响血管弹性蛋白酶表达

Primary Study on Effect of Platelet-derived Growth Factor on the Expression of the Vascular Elastase

探讨球囊损伤后血管平滑肌细胞丝氨酸弹性蛋白酶表达增加的机理。用球囊导管损伤Wistar系雄性大鼠主动脉或颈总动脉。以血小板源性生长因子A和大鼠胰腺丝氨酸弹性蛋白酶的地高辛标记RNA探针进行原位杂交 ,并用抗 5 溴脱氧尿嘧啶抗体进行双重染色。用抗血小板源性生长因子AA、抗血小板源性生长因子BB、抗胰腺弹性蛋白酶、抗人增殖细胞核抗原等抗体进行免疫染色或免疫双重染色。电镜观察细胞的超微结构。结果发现 :①在球囊损伤后 0 .5～ 4h ,血小板源性生长因子mRNA表达细胞多于弹性蛋白酶mRNA表达细胞 ;②增殖细胞和迁移细胞既有血小板源性生长因子mRNA和其蛋白表达 ,又有弹性蛋白酶mRNA和其蛋白表达 ;③迁移细胞多为增殖细胞核抗原染色阳性 ,细胞内可见到核分裂像。提示血小板源性生长因子可能是刺激中膜平滑肌细胞增殖、迁移并使其弹性蛋白酶增加的影响因子之一。

Aim To investigate the mechanism of the expression increase of the vascular serine elastase after the vascular injury by balloon catheter from the point of view of platelet-derived growth factor (PDGF). Method The rat abdominal aorta and carotid arteries of the male Wistar rats were injured by balloon catheters. In situ hybridization was performed by the RNA probe of PDGF-A and rat pancreatic elastase which was labeled with digoxin, and the double immunostaining for 5-bromo-2'-deoxyuridine (BrdU) was performed. The immunostaining or double immunostaining had been done with the antibodies against PDGF-A, B, pancreatic elastase, proliferating cell nuclear antigen. The ultramicrostructure of the vascular cells was observed with transmission electron microscope. Results In the very early stage of balloon injury, the cells of expressing PDGF-A mRNA were more than those of expressing elastase mRNA. The proliferating cells and migrating cells not only expressed PDGF-A mRNA and PDGF-A protein, but also expressed elastase mRNA and elastase protein. Most of the migrating cells were positive for proliferating cell nuclear antigen, the karyomitosis in the cells could be observed. Conclusion PDGF may be a factor that stimulate the proliferation, the migration and the expression increase of elastase of the medial smooth muscle cells.