Kallikrein-related peptidase 12 (KLK12) is a kallikrein family peptidase involved in angiogenesis - a complex biological process in which the sprouting, migration and stabilization of endothelial cells requires extracellular matrix remodeling. To characterize the molecular mechanisms associated with KLK12's proangiogenic activity, we evaluated its ability to hydrolyze various matrix proteins. Our results show that KLK12 efficiently cleaved the human extracellular matrix proteins fibronectin and tenascin, both of which are involved in the regulation of endothelial cell adhesion and migration. For fibronectin, the major proteolytic product generated by KLK12 was a 29 kDa fragment containing the amino-terminal domain and the first five type I fibronectin-domains, which are essential for regulating fibronectin assembly. We also demonstrated that KLK12-mediated fibronectin proteolysis antagonizes fibronectin polymerization and fibronectin fibril formation by endothelial cells, leading to an increase in cell migration. Furthermore, a polyclonal antibody raised against KLK12's proteolytic cleavage site on fibronectin prevented the KLK12-dependent inhibition of fibronectin polymerization and the KLK12-mediated pro-migratory effect on endothelial cells. Taken as a whole, our results indicate that KLK12's proangiogenic effect is mediated through several molecular mechanisms.

中文翻译：

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人激肽释放酶相关肽酶 12 通过重塑纤连蛋白基质来刺激内皮细胞迁移。


激肽释放酶相关肽酶 12 (KLK12) 是一种参与血管生成的激肽释放酶家族肽酶，血管生成是一个复杂的生物过程，其中内皮细胞的发芽、迁移和稳定需要细胞外基质重塑。为了表征与 KLK12 促血管生成活性相关的分子机制，我们评估了其水解各种基质蛋白的能力。我们的结果表明，KLK12 有效裂解人细胞外基质蛋白纤连蛋白和腱蛋白，这两种蛋白都参与内皮细胞粘附和迁移的调节。对于纤连蛋白，KLK12 产生的主要蛋白水解产物是包含氨基末端结构域和前五个 I 型纤连蛋白结构域的 29 kDa 片段，这对于调节纤连蛋白组装至关重要。我们还证明，KLK12 介导的纤连蛋白水解会拮抗内皮细胞的纤连蛋白聚合和纤连蛋白原纤维形成，导致细胞迁移增加。此外，针对纤连蛋白上 KLK12 的蛋白水解切割位点产生的多克隆抗体可阻止 KLK12 依赖性的纤连蛋白聚合抑制以及 KLK12 介导的内皮细胞促迁移效应。总的来说，我们的结果表明 KLK12 的促血管生成作用是通过多种分子机制介导的。