Cell-demanded liberation of VEGF121 from fibrin implants induces local and controlled blood vessel growth
Cell-demanded liberation of VEGF121 from fibrin implants induces local and controlled blood vessel growth
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DOI：
10.1161/01.res.0000126411.29641.08
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发表时间：
2004-04-30
影响因子：
20.1
通讯作者：
Zisch, AH
中科院分区：
文献类型：
--
作者：
Ehrbar, M;Djonov, VG;Zisch, AH
尽管血管内皮生长因子（VEGF）已被描述为一种有效的血管生成刺激物，但其在治疗中的应用仍然困难：暴露于VEGF形成的血管往往会畸形和渗漏。在自然界中，VEGF的主要形式具有ECM组分的结合位点，该结合位点将其维持在固定状态，直到通过局部细胞酶活性释放。在这项研究中，我们提出了一种VEGF的工程化变体，α（2）PI（1-8）-VEGF（121），它模拟了这种基质结合和通过局部细胞相关酶活性的细胞介导释放的概念，在与肾脏相关的生物基质纤维蛋白中起作用。我们表明，基质结合的α（2）PI（1-8）-VEGF（121）被保护免于清除，与混合到纤维蛋白中的天然VEGF（121）相反，后者作为被动扩散爆发完全释放。对鸡胚绒毛尿囊膜（CAM）和成年小鼠进行移植研究，以评估和比较由基质结合的α 2 PI（1-8）-VEGF（121）或天然可扩散VEGF（121）配制的纤维蛋白植入物诱导的新生血管的数量和质量。我们的CAM测量表明，细胞需要的α 2 PI（1-8）-VEGF（121）的释放增加了新的动脉和静脉分支的形成，而暴露于被动释放的野生型VEGF（121）主要诱导毛细血管丛内的混乱变化。具体而言，我们在几个水平上的分析，从内皮细胞形态和内皮与内皮周细胞的相互作用，到血管分支和网络组织，揭示了α 2 PI（1-8）-VEGF（121）比天然VEGF（121）更有效地诱导血管形成，并且这些血管在光学显微镜和超微结构水平上具有更正常的形态。在小鼠中的渗透性研究证实，由α（2）PI（1-8）-VEGF（121）诱导的血管不会渗漏。总之，从纤维蛋白植入物中释放工程化VEGF（121）的细胞需求可能是诱导局部血管生成的一种治疗安全和实用的方式。
Although vascular endothelial growth factor (VEGF) has been described as a potent angiogenic stimulus, its application in therapy remains difficult: blood vessels formed by exposure to VEGF tend to be malformed and leaky. In nature, the principal form of VEGF possesses a binding site for ECM components that maintain it in the immobilized state until released by local cellular enzymatic activity. In this study, we present an engineered variant form of VEGF, alpha(2)PI(1-8)-VEGF(121), that mimics this concept of matrix-binding and cell-mediated release by local cell-associated enzymatic activity, working in the surgically-relevant biological matrix fibrin. We show that matrix-conjugated alpha(2)PI(1-8)-VEGF(121) is protected from clearance, contrary to native VEGF(121) mixed into fibrin, which was completely released as a passive diffusive burst. Grafting studies on the embryonic chicken chorioallantoic membrane (CAM) and in adult mice were performed to assess and compare the quantity and quality of neovasculature induced in response to fibrin implants formulated with matrix-bound alpha2PI(1-8)-VEGF(121) or native diffusible VEGF(121). Our CAM measurements demonstrated that cell-demanded release of alpha2PI(1-8)-VEGF(121) increases the formation of new arterial and venous branches, whereas exposure to passively released wild-type VEGF(121) primarily induced chaotic changes within the capillary plexus. Specifically, our analyses at several levels, from endothelial cell morphology and endothelial interactions with periendothelial cells, to vessel branching and network organization, revealed that alpha2PI(1-8)-VEGF(121) induces vessel formation more potently than native VEGF(121) and that those vessels possess more normal morphologies at the light microscopic and ultrastructural level. Permeability studies in mice validated that vessels induced by alpha(2)PI(1-8)-VEGF(121) do not leak. In conclusion, cell-demanded release of engineered VEGF(121) from fibrin implants may present a therapeutically safe and practical modality to induce local angiogenesis.