Roth Detlev, Piekarek Michael, Paulsson Mats, Christ Hildegard, Bloch Wilhelm, Krieg Thomas, Davidson Jeffrey M, Eming Sabine A
Department of Dermatology, University of Cologne, Joseph-Stelzmann Str. 9, 50931 Köln, Germany.
Am J Pathol. 2006 Feb;168(2):670-84. doi: 10.2353/ajpath.2006.050372.
Plasmin-catalyzed cleavage of the vascular endothelial growth factor (VEGF)-A isoform VEGF165 results in loss of its carboxyl-terminal heparin-binding domain and significant loss in its bioactivity. Little is known about the in vivo significance of this process. To investigate the biological relevance of the protease sensitivity of VEGF165 in wound healing we assessed the activity of a VEGF165 mutant resistant to plasmin proteolysis (VEGF165(A111P)) in a genetic mouse model of impaired wound healing (db/db mouse). In the present study we demonstrate that in this mouse model plasmin activity is increased at the wound site. The stability of the mutant VEGF165 was substantially increased in wound tissue lysates in comparison to wild-type VEGF165, thus indicating a prolonged activity of the plasmin-resistant VEGF165 mutant. The db/db delayed healing phenotype could be reversed by topical application of wild-type VEGF165 or VEGF165(A111P). However, resistance of VEGF165 to plasmin cleavage resulted in the increased stability of vascular structures during the late phase of healing due to increased recruitment of perivascular cells and delayed and reduced endothelial cell apoptosis. Our data provide the first indication that plasmin-catalyzed cleavage regulates VEGF165-mediated angiogenesis in vivo. Inactivation of the plasmin cleavage site Arg110/Ala111 may preserve the biological function of VEGF165 in therapeutic angiogenesis under conditions in which proteases are highly active, such as wound repair and inflammation.
纤溶酶催化的血管内皮生长因子（VEGF）-A亚型VEGF165的裂解导致其羧基末端肝素结合域的丧失以及生物活性的显著丧失。关于这一过程在体内的意义知之甚少。为了研究VEGF165蛋白酶敏感性在伤口愈合中的生物学相关性，我们在伤口愈合受损的基因小鼠模型（db/db小鼠）中评估了对纤溶酶蛋白水解具有抗性的VEGF165突变体（VEGF165(A111P)）的活性。在本研究中，我们证明在该小鼠模型中，伤口部位的纤溶酶活性增加。与野生型VEGF165相比，突变体VEGF165在伤口组织裂解物中的稳定性显著增加，这表明抗纤溶酶的VEGF165突变体具有延长的活性。通过局部应用野生型VEGF165或VEGF165(A111P)可逆转db/db小鼠延迟愈合的表型。然而，VEGF165对纤溶酶裂解的抗性导致愈合后期血管结构的稳定性增加，这是由于血管周围细胞募集增加以及内皮细胞凋亡延迟和减少所致。我们的数据首次表明，纤溶酶催化的裂解在体内调节VEGF165介导的血管生成。在蛋白酶高度活跃的条件下，如伤口修复和炎症，纤溶酶裂解位点Arg110/Ala111的失活可能会保留VEGF165在治疗性血管生成中的生物学功能。
