Southgate K M, Fisher M, Banning A P, Thurston V J, Baker A H, Fabunmi R P, Groves P H, Davies M, Newby A C
Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, UK.
Circ Res. 1996 Dec;79(6):1177-87. doi: 10.1161/01.res.79.6.1177.
Basement membrane-degrading metalloproteinases (gelatinases) appear necessary for vascular smooth muscle cell migration and proliferation in culture and for intimal migration of cells after balloon injury to the rat carotid artery. We investigated in the present study the secretion of gelatinases from pig carotid artery tissue after balloon injury. Segments of injured artery and segments proximal and distal to the area of injury were removed 3, 7, and 21 days after balloon dilatation. Medial explants from these segments were then cultured for 3 days, and the serum-free conditioned media were subjected to gelatin zymography. Production of 72- and 95-kD gelatinases was quantified by densitometry. Balloon-injured segments secreted significantly more 72- and 95-kD gelatinase than did paired distal segments at all time points. Release of both gelatinase activities was increased at 3 and 7 days relative to segments from uninjured arteries but declined again by 21 days after balloon injury. Similar results were found for gelatinase levels in extracts of arterial tissue. Consistent with the protein secretion data, in situ hybridization demonstrated that the mRNAs for both gelatinases were upregulated after balloon injury. Expression was prominent in medial smooth muscle cells, particularly around foci of necrosis, and in neointimal cells 3 and 7 days after balloon injury; 72-kD gelatinase mRNA persisted after 21 days and was prominent in regrown endothelial cells. The upregulation of gelatinase activity paralleled the time course of smooth muscle cell migration and proliferation in this model. We conclude that increased gelatinase production occurs in response to balloon injury and may play a role in permitting migration and proliferation of vascular smooth muscle cells.
基底膜降解金属蛋白酶（明胶酶）似乎是培养的血管平滑肌细胞迁移和增殖以及大鼠颈动脉球囊损伤后细胞内膜迁移所必需的。在本研究中，我们调查了球囊损伤后猪颈动脉组织中明胶酶的分泌情况。球囊扩张后3天、7天和21天，切除损伤动脉段以及损伤区域近端和远端的动脉段。然后将这些段的中膜外植体培养3天，对无血清条件培养基进行明胶酶谱分析。通过光密度测定法定量72-kD和95-kD明胶酶的产生。在所有时间点，球囊损伤段分泌的72-kD和95-kD明胶酶均显著多于配对的远端段。相对于未损伤动脉段，两种明胶酶活性在3天和7天时均增加，但在球囊损伤后21天再次下降。动脉组织提取物中的明胶酶水平也得到了类似结果。与蛋白质分泌数据一致，原位杂交表明球囊损伤后两种明胶酶的mRNA均上调。在中膜平滑肌细胞中表达明显，特别是在坏死灶周围，以及球囊损伤后3天和7天的新生内膜细胞中；21天后72-kD明胶酶mRNA持续存在，并在再生的内皮细胞中显著表达。在该模型中，明胶酶活性的上调与平滑肌细胞迁移和增殖的时间进程平行。我们得出结论，球囊损伤后明胶酶产生增加，可能在允许血管平滑肌细胞迁移和增殖中发挥作用。
