Engineering NRG signaling for therapeutic vascularization in diabetic wounds

描述(由申请人提供)：糖尿病是一种几乎是大流行的疾病，与无法愈合的足部溃疡(DFU)相关的发病率很高。血管生成受损是糖尿病患者伤口愈合的一个限制因素，因此治疗性血管化疗法已被应用于治疗DFU。然而，基于细胞的治疗性血管形成尚未在大型临床试验中得到验证，传统的药物和蛋白质治疗在很大程度上已经失败。 也不会让人失望。因此，开发治疗DFU的改进的血管形成方法将满足临床上的一项重要需求。分子治疗性血管形成的一个新策略是ErbB受体家族与神经调节蛋白-1(NRG)的结合。虽然在癌症和许多器官系统中都有很好的研究，但对NRG/ErbB信号在血管形成中的作用知之甚少。NRG是一种已知的内皮细胞有丝分裂原，在小鼠模型中被证明是血管生成反应的关键介质。NRG剪接变异体以及NRG亚家族中的其他蛋白也是潜在的内皮效应因子，因为它们与ErbB3和ErbB4受体具有高亲和力。大量证据表明，ErbB受体在二聚化后启动信号传递，最常见的是与ErbB家族的另一个成员。由于已知有四种ErbB受体，其中一种(ErbB2)没有已知的配体，被认为是以准激活状态存在的，NRG的剪接变体能够通过多个ErbB二聚体或寡聚体诱导信号，每一组都可能激活一条独特的途径。因此，NRG/ErbB信号在血管形成中的作用尚不清楚，最大限度地发挥ErbB配体在治疗性血管形成中的作用的潜力仍未实现。在这一应用中，将通过追求三个特定的目标来探索ErbB受体在血管形成中的作用。目的1验证内皮细胞ErbB信号偏向调控内皮细胞表型的假设。目标2中的实验将验证这样的假设，即局部输送ErbB受体配体可以通过内皮ErbB受体介导的机制在体内刺激治疗性血管形成。在目标3中，将检验通过整合ErbB受体配体的局部传递来增强皮肤替代物植入的假设。在这项工作结束时，意义重大 将采取步骤阐明ErbB受体在血管形成中的作用，并确定其在糖尿病伤口愈合中作为治疗靶点的潜力。此外，该项目具有更广泛的影响；这里开发的治疗策略有可能成为组织工程领域的一项使能技术。与公共健康的相关性-通过接触ErbB受体进行治疗血管化术是一种新的、有前途的方法，可以降低与未愈合的糖尿病足部溃疡相关的发病率和死亡率。在这里，提出了利用新的技术和策略来提高对ErbB受体在血管形成中的机制的理解。这一进展将使糖尿病创面愈合的新治疗方法成为可能。

DESCRIPTION (provided by applicant): Diabetes is a near-pandemic disease with substantial morbidity associated with non-healing foot ulcers (DFUs). Impaired angiogenesis is a limiting factor for wound healing in diabetics, and thus therapeutic vascularization approaches have been applied to treat DFUs. However, cell-based therapeutic vascularization has yet to be validated in large clinical trials and conventional drug and protein treatments have largely failed or been disappointing. Therefore, the development of improved therapeutic vascularization approaches to treat DFUs would fill a critical clinical need. One emerging strategy for molecular therapeutic vascularization is engagement of the ErbB receptor family with Neuregulin-1 (NRG). Though well studied in cancer and many organ systems, relatively little is known about the role of NRG/ErbB signaling in vascularization. NRG is a known endothelial cell mitogen and has been shown to be a crucial mediator of the angiogenic response to ischemia in a mouse model. NRG splice variants, as well as other proteins in the NRG subfamily, are also potential endothelial effectors via their high binding affinity to receptors ErbB3 and ErbB4. Overwhelming evidence indicates that ErbB receptors initiate signaling following dimerization, most often with another ErbB family member. Given that there are four known ErbB receptors, one of which (ErbB2) does not have a known ligand and is thought to exist in a quasi-activated state, splice variants of NRG are capable of inducing signaling through multiple ErbB dimers or oligomers, each set of which may activate a unique pathway. Thus, the role of NRG/ErbB signaling in vascularization is unclear and the potential to maximize the efficacy of ErbB ligands in therapeutic vascularization remains unrealized. In this application, the role of ErbB receptors in vascularization will be explored by pursuing three specific aims. Aim 1 will test the hypothesis that biasing of endothelial ErbB signaling can regulate endothelial cell phenotype. Experiments in Aim 2 will test the hypothesis that local delivery of ErbB receptor ligands can stimulate therapeutic vascularization in vivo via an endothelial ErbB receptor-mediated mechanism. In Aim 3, the hypothesis that skin substitute engraftment can be enhanced via integration with local delivery of ErbB receptor ligands will be tested. At the conclusion of this work, significant steps towards clarifying the role of ErbB receptors in vascularization and determining their potential as therapeutic targets in diabetic wound healing will have been taken. Furthermore, this project has broader implications; the therapeutic strategies developed here have the potential to serve as an enabling technology in the field of tissue engineering. Relevance to Public Health - Therapeutic vascularization via engagement of ErbB receptors is a novel, promising approach to decreasing morbidity and mortality associated with non-healing diabetic foot ulcers. Here, the use of new technology and strategies to develop an improved mechanistic understanding of ErbB receptors in vascularization is proposed. This advances would enable new therapeutic approaches in diabetic wound healing.