Reprogramming Macrophages to Improve Vascular Healing in Diabetes

患有糖尿病的美国退伍军人伤口愈合受损是发病率和死亡率的主要来源，因为 以及退伍军人管理局医疗保健系统的巨大财政压力。目前的治疗模式，包括 清创坏死组织、控制感染、局部溃疡护理、机械卸载和管理 血糖水平，充其量是适度有效的。尽管在这一领域进行了大量研究，但关键分子 调控血管生成导向的伤口愈合的机制仍然没有得到最低限度的定义。最近，我们的团队 确认早期炎性巨噬细胞产生血管内皮生长因子-A在促进后续反应中的重要作用 创面愈合所需的血管生成/动脉生成。我们测定了巨噬细胞促血管生成 β-A异构体转录依赖于自分泌的IL-1-IL-1R信号 NF-κB与κ-A启动子区域的结合。类似于巨噬细胞IL-1β缺失小鼠， 实验性糖尿病小鼠表现出组织促血管生成血管内皮生长因子-A表达受损和 随之而来的伤口愈合和动脉生成减少。在炎症条件下，骨髓 糖尿病小鼠来源的巨噬细胞表达减少的血管内皮生长因子-A与减少一致 对IL-1β的信号反应，有趣的是，几个关键的IL-1R信号的表达减少 成分复杂，提示对IL-1β的反应性受损。我们的工作模式是DM IL-1R信号与血管内皮生长因子A转录解偶联，导致血管生成原血管生成受损 随之而来的是基于血管生成的愈合能力下降。在这份促进多样性的退伍军人研究补充资料中 建议，我们寻求通过有效地绕过IL-1R信号和 直接上调NF-κB活性。主要的假设是，对糖尿病介导的损伤的挽救 直接上调NF-κB活性依赖血管生成是一种可行的治疗性血管生成方法 伤口愈合的策略。我们的目标是：1)证明组成活性的IKK-2的髓系表达 可以挽救血管生成前血管生成因子-A的表达和血管内皮生长因子-A依赖的血管生成 巨噬细胞IL-1R缺失；和2)证实骨髓基质细胞表达组成性活性的IKK-2 足以增加实验性糖尿病小鼠的伤口愈合、血管生成和动脉生成。通过 操纵IL-1R信号依赖的血管内皮生长因子-A表达下游的机制通路 通过治疗重新激活糖尿病巨噬细胞血管生成和伤口愈合反应，我们将验证 具有巨大潜力影响美国退伍军人和所有人生活的治疗性血管生成战略 美国人。此外，这项提议为墨西哥人罗伯托·门德斯博士提供了一个强有力的培训平台。 美国和美国退伍军人，致力于发展以退伍军人为基础的研究职业生涯 健康。这些研究将为他提供重要的初步数据，以支持他自己的VA CDA-1申请 在未来两年内提出建议。

Impaired wound healing in US veterans with diabetes mellitus is a major source of morbidity and mortality as well as a large financial strain on the VA health care system. Current treatment paradigms, including debridement of necrotic tissue, infection control, local ulcer care, mechanical off-loading, and management of blood glucose levels, are modestly effective at best. Despite much research in this area, the critical molecular mechanisms regulating angiogenesis-directed wound healing remain minimally defined. Recently, our group identified an important role for early inflammatory macrophage VEGF-A production in promoting consequent angiogenesis/ arteriogenesis required for adequate wound healing. We determined macrophage proangiogenic VEGF-A isoform transcription to be dependent on autocrine IL-1β-IL-1R signaling through activation of nuclear NF-κB and binding of NF-κB to the VEGF-A promoter region. Analogous to macrophage IL-1β-deleted mice, mice with experimental diabetes demonstrated impaired tissue proangiogenic VEGF-A expression and consequent reductions in wound healing and arteriogenesis. Under inflammatory conditions, bone marrow derived macrophages (BMDMs) from diabetic mice expressed reduced VEGF-A consistent with reduced signaling response to IL-1β, and interestingly, there is reduced expression of several key IL-1R signaling complex components, suggesting an impaired responsiveness to IL-1β. Our working model is that DM uncouples IL-1R signaling from VEGF-A transcription, causing impaired proangiogenic VEGF-A expression and consequent decreased angiogenesis-based healing. In this VA Research Supplement to Promote Diversity proposal, we seek to reactivate macrophage VEGF-A expression by effectively bypassing IL-1R signaling and upregulating NF-κB activity directly. The primary hypothesis is that rescue of DM-mediated impairments in VEGF-A-dependent angiogenesis via direct upregulation of NF-κB activity is a viable therapeutic angiogenesis strategy for wound healing. We aim to 1) demonstrate that myeloid expression of constitutively active IKK-2 can rescue proangiogenic VEGF-A expression and VEGF-A-dependent angiogenesis in the context of macrophage IL-1R-deletion; and 2) demonstrate that BMDMs programed to express constitutively active IKK-2 are sufficient to increase wound healing angiogenesis and arteriogenesis using mice with experimental DM. By manipulating mechanistic pathways downstream of IL-1R signaling-dependent VEGF-A expression to therapeutically reactivate diabetic macrophage angiogenic and wound healing responses, we will validate a therapeutic angiogenesis strategy that has tremendous potential to impact the lives of US veterans and all Americans. Moreover, this proposal serves as a robust training platform for Dr. Roberto Mendez, a Mexican American and US veteran, who is committed to developing a VA-based research career focused on veteran health. These studies will provide him with important preliminary data to support his own VA CDA-1 application proposal within the next two years.