Angiogenesis Laboratory, CIPM, Instituto Português de Oncologia Francisco Gentil, Lisboa, Portugal.
Biomaterials. 2011 Oct;32(29):7096-105. doi: 10.1016/j.biomaterials.2011.06.022. Epub 2011 Jul 8.
Severe skin loss constitutes a major unsolved clinical problem worldwide. For this reason, in the last decades there has been a major push towards the development of novel therapeutic approaches to enhance skin wound healing. Neo-vessel formation through angiogenesis is a critical step during the wound healing process. Besides the contribution of pre-existing endothelial cells (EC), endothelial progenitor cells (EPCs) have also been implicated in wound healing acting either by differentiating into EC that incorporate the neo-vessels, or via the production of paracrine factors that improve angiogenesis. Here we tested the importance of different extracellular matrices (ECM) in regulating the angiogenic and wound healing potential of cord blood-derived EPC (CB-EPC). We compared the properties of several ECM and particularly of fibrin fragment E (FbnE) in regulating EPC adhesion, proliferation, differentiation and healing-promotion in vitro and in vivo. Our results show that CB-EPCs have increased adhesion and endothelial differentiation when plated on FbnE compared to collagens, fibronectin or fibrin. Using integrin neutralizing antibodies, we show that CB-EPC adhesion to FbnE is mediated by integrin α5β1. Gene expression analysis of CB-EPCs plated on different substrates revealed that CB-EPC grown on FbnE shows increased expression of paracrine factors such as VEGF-A, TGF-β1, SDF-1, IL-8 and MIP-1α. Accordingly, conditioned media from CB-EPC grown on FbnE induced EC tube formation and monocyte migration in vitro. To test the wound healing effects of FbnE in vivo we used an FbnE enriched scaffold in a cutaneous wound healing mouse model. In accordance with our in vitro data, co-administration of the FbnE enriched scaffold with CB-EPC significantly accelerated wound closure and wound vascularization, compared FbnE enriched scaffold alone or to using collagen-based scaffolds. Our results show that FbnE modulates several CB-EPC properties in vivo and in vitro, and as such promotes wound healing. We suggest the use of FbnE-based scaffolds represents a promising approach to resolve wound healing complications arising from different pathologies.
严重的皮肤损伤是全球尚未解决的一个主要临床问题。正因为如此，在过去的几十年里，人们一直在大力研究新的治疗方法，以促进皮肤伤口愈合。血管生成过程中的新血管形成是伤口愈合过程中的一个关键步骤。除了已有内皮细胞（EC）的贡献外，内皮祖细胞（EPC）也被认为在伤口愈合中发挥作用，要么通过分化为包含新血管的 EC，要么通过产生旁分泌因子来改善血管生成。在这里，我们测试了不同细胞外基质（ECM）在调节脐带血来源的内皮祖细胞（CB-EPC）的血管生成和伤口愈合潜力中的重要性。我们比较了几种 ECM 的特性，特别是纤维蛋白片段 E（FbnE）在调节 CB-EPC 黏附、增殖、分化和体内外促进愈合方面的特性。我们的结果表明，与胶原蛋白、纤维连接蛋白或纤维蛋白相比，CB-EPC 在 FbnE 上的黏附和内皮分化能力增强。通过整合素中和抗体，我们证明 CB-EPC 对 FbnE 的黏附是由整合素 α5β1介导的。将 CB-EPC 接种在不同底物上进行基因表达分析表明，在 FbnE 上生长的 CB-EPC 表达增加了旁分泌因子，如 VEGF-A、TGF-β1、SDF-1、IL-8 和 MIP-1α。相应地，在 FbnE 上生长的 CB-EPC 的条件培养基在体外诱导 EC 管形成和单核细胞迁移。为了在体内测试 FbnE 在伤口愈合中的作用，我们在皮肤伤口愈合小鼠模型中使用了富含 FbnE 的支架。与我们的体外数据一致，与单独使用富含 FbnE 的支架或使用基于胶原蛋白的支架相比，FbnE 富含支架与 CB-EPC 的共同给药显著加速了伤口闭合和血管化。我们的结果表明，FbnE 可调节 CB-EPC 的几种体内和体外特性，并可促进伤口愈合。我们建议使用基于 FbnE 的支架是解决不同病理引起的伤口愈合并发症的一种有前途的方法。
