摘要
目的研究血小板膜表面糖蛋白GPⅡb/Ⅲa是否在血小板-内皮细胞作用过程中促进蛋白水解酶表达和分泌。方法体外培养人脐静脉内皮细胞(HUVEC),分别加入无血清培养基,静息期血小板,活化后血小板及IL-1β。上清液及细胞分别用于酶谱法检测MMP-2和MMP-9活性,以及RT-PCR分析mRNA表达。结果HUVEC与活化血小板共同培养后,酶谱法显示,与对照组相比,未活化的血小板轻微诱导MMP-2和MMP-9分泌,而活化状态的血小板能显著诱导这二者的分泌,与IL-1β的作用相当;而且还可以见到62 kD MMP-2活化形式。加入阻断剂GRGDSP以及GPⅡb/Ⅲa单克隆抗体(7E3)作用后检测发现,MMP-2和MMP-9分泌减少。与活化血小板共同培养后的HUVEC表面表达uPAR和MT1-MMP以及上清液中MMP-2的mRNA与对照组相比明显增高,而静息状态的血小板作用不显著。加入GRGDSP或7E3后,mRNA的表达降低。结论(1)黏附于血管壁的血小板上某一特定区域在细胞外基质降解过程中发挥重要作用;(2)GPⅡb/Ⅲa阻断剂可能抑制血小板在不稳定斑块部位聚集,防止出现管腔狭窄;还可能防止血小板黏附等一系列炎症反应引发的细胞外基质降解和斑块破裂。
Objective To explore whether glycoprotein （GP） Ⅱ b/Ⅲa during plate-endothelium interactions can promote protease expression and secretion. Methods Human umbilical vein endothelial cells （HUVECs） cultured in vitro were added serum free medium, resting platelets, α-thrombin-stimulated platelets, and IL-1β. The supematant was used for SDS-PAGE zymography and RT-PCR to be analyzed by flow cytometry. Results HUVEC was incubated with α-thrombin-activated platelets. SDS-PAGE zymography revealed expression of MMP-2 and MMP-9 was only slightly induced by resting platelets. However, adhesion of activated platelets induced secretion of 2 MMPs to a comparable extent as achieved by IL-1β. In addition, a second,lower band at 62 kD revealed MMP-2 activation on adhesion of activated platelets. Endothelial expression of MMP-2 and MMP-9 was significantly restrained by GRGDSP and mAbs anti-GP Ⅱb/Ⅲa （7E3）. HUVEC incubation with α-thrombin-activated platelets induced mRNA expression of MMP-2 ,MT1-MMP,and uPAR comparable with the control group ,but nonstimulated platelets did nothing. Expression of mRNA after added GRGDSP or 7E3 decreased greatly. Conclusions The platelets can focus matrix-degrading activity to the particular sites of platelet adhesion at the vessel wall. GP Ⅱ b/Ⅲ a blockade may not only inhibit platelet aggregation at the vulnerable plaque and thereby prevent physical vessel occlusion but also may prevent platelet adhesion mediated inflammatory cascades leading to matrix degradation and plaque rupture.
出处
《中国老年学杂志》
CAS
CSCD
北大核心
2006年第7期890-892,共3页
Chinese Journal of Gerontology
