Inhibition of bFGF/EGF-dependent enclothelial cell proliferation by the hyaluronan-binding protease from human plasma
Inhibition of bFGF/EGF-dependent enclothelial cell proliferation by the hyaluronan-binding protease from human plasma
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DOI：
10.1078/0171-9335-00349
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发表时间：
2004-01-01
影响因子：
6.6
通讯作者：
Dodt, J
中科院分区：
文献类型：
--
作者：
Etscheid, M;Beer, N;Dodt, J
最近，我们发现了一种血浆丝氨酸蛋白酶，与肝素或透明质酸等糖胺聚糖具有高亲和力，称为透明质酸结合蛋白酶（HABP）。由于在细胞表面和细胞外基质中发现了糖胺聚糖，因此假定了这种血浆蛋白酶在细胞周围环境中的生理作用。在这里，我们研究了HABP对内皮细胞生长调节的影响。我们发现，HABP有效地防止碱性成纤维细胞生长因子/表皮生长因子（bFGF/EGF）依赖的人脐静脉内皮细胞的增殖。粘附分子的蛋白水解裂解被发现参与，但不是唯一负责的抗增殖活性。用HABP预处理补充有生长因子的细胞培养基表明，生长抑制不需要活性蛋白酶和细胞之间的直接接触。体外研究显示HABP具有生长因子导向活性，导致复合和部分水解，从而使碱性成纤维细胞生长因子（一种有效的内皮细胞有丝分裂原）失活。肝素和硫酸乙酰肝素完全保护bFGF免受HAB的络合和切割，尽管已知这些糖胺聚糖增强HABP的蛋白水解活性。这一发现表明，游离循环bFGF，而不是bFGF结合硫酸乙酰肝素蛋白聚糖将是一种生理底物。总之，bFGF依赖性内皮细胞生长的下调代表了HABP在生理或病理过程如血管生成、伤口愈合或肿瘤发展中控制细胞生长的重要机制。
Recently we identified a plasma serine protease with a high affinity to glycosaminoglycans like heparin or hyaluronic acid, termed hyaluronan-binding protease (HABP). Since glycosaminoglycans are found on cell surfaces and in the extracellular matrix a physiological role of this plasma protease in a pericellular environment was postulated. Here we studied the influence of HABP on the regulation of endothelial cell growth. We found that HABP efficiently prevented the basic fibroblast growth factor/epidermal growth factor (bFGF/EGF)-dependent proliferation of human umbilical vein endothelial cells. Proteolytic cleavage of adhesion molecules was found to be involved, but was not solely responsible for the anti-proliferative activity. Pre-treatment of growth factor-supplemented cell culture medium with HABP indicated that no direct contact between the active protease and cells was required for growth inhibition. In vitro studies revealed a growth factor-directed activity of HABP, resulting in complexation and partial hydrolysis and, thus, inactivation of basic fibroblast growth factor, a potent mitogen for endothelial cells. Heparin and heparan sulfate fully protected bFGF from complexation and cleavage by HAB, although these glycosaminoglycans are known to enhance the proteolytic activity of HABP. This finding suggested that free circulating bFGF rather than bFGF bound to heparan sulfate proteoglycans would be a physiologic substrate. In conclusion, down-regulation of bFGF-dependent endothelial cell growth represents an important mechanism through which HABP could control cell growth in physiologic or pathologic processes like angiogenesis, wound healing or tumor development.