Surgical Wound Repair: Role of A Neuroendothelial Axis

描述(由申请人提供)： 这项建议探索了皮肤损伤反应过程中皮肤感觉神经纤维和内皮细胞之间发生的细胞信号通路。随着大面积烧伤后患者存活率的提高，增生性瘢痕形成导致的残疾已成为一个重要的临床问题，在美国每年影响多达10万名患者。这种对伤害的异常反应导致了病人的痛苦，因为难看的畸形和毁灭性的瘙痒和疼痛。疤痕血管丰富，神经支配增多。相比之下，糖尿病无法愈合的溃疡有微血管病变和神经减少。我们预计，在增生性瘢痕中，内皮细胞增殖和神经营养素合成增加会导致血管增多和瘙痒。我们的长期假设是，皮肤损伤后，1)感觉神经纤维分泌神经肽，如P物质，调节内皮细胞对损伤的反应；2)微血管内皮细胞分泌神经营养因子，调节神经纤维再生。我们将通过解决以下目标来验证我们的假设：目标1：确定P物质调节内皮细胞前炎症反应的细胞内机制。我们将确定P物质是否通过1)G蛋白偶联途径或2)细胞形态改变和细胞骨架重组来诱导内皮细胞产生神经生长因子、血管内皮生长因子和白介素8。目的：探讨一氧化氮合酶在P物质介导的内皮细胞损伤反应中的作用。我们将确定导致神经生长因子、血管内皮生长因子和白介素8合成的P物质信号通路是否依赖于一氧化氮。目的3：确定哪些内皮细胞衍生的介质调节神经细胞的萌发。我们将通过鉴定调节感觉神经纤维发芽的内皮细胞衍生神经营养因子来评估我们假设的第二个方面。使用神经生长的体外模型，我们将验证目标1和2中的操作减少了负责神经分化的可溶性介质。目的：研究转基因小鼠和突变糖尿病小鼠神经肽活性如何改变对损伤的反应。我们将使用正常小鼠、糖尿病小鼠和神经元型一氧化氮合酶、诱导型一氧化氮合酶或内皮型一氧化氮合酶靶向中断的小鼠的切除创伤模型，确定P物质如何调节皮肤对损伤的反应。

DESCRIPTION (provided by applicant): This proposal explores cell signaling pathways that occur between cutaneous sensory nerve fibers and endothelial cells during response to cutaneous injury. With increased patient survival following large burn injuries, disability due to hypertrophic scar formation has become an important clinical problem that affects as many as 100,000 patients per year in the United States. This abnormal response to injury results in significant patient misery due to both the unsightly deformity and also devastating itching and pain. The scars have hypervascularity and increased innervation. In contrast, non-healing ulcers of diabetes mellitus have microangiopathy and decreased innervation. We anticipate that in hypertrophic scars increased endothelial cell proliferation and neurotrophin synthesis leads to the hypervascularity and pruritis. Our Iong term hypothesis is that followinq cutaneous injury, 1) sensory nerve fibers secrete neuropeptides such as substance P that regulate endothelial cell response to injury and 2) microvascular endothelial cells secrete neurotrophins that regulate nerve fiber regeneration. We will test our hypothesis by addressing the following aims: Aim 1: To determine intracellular mechanisms by which substance P regulates endothelial cell proinflammatory response. We will determine whether the substance P induces endothelial cell production of nerve growth factor, vascular endothelial growth factor and interleukin 8 by 1) G-protein coupled pathways or 2) cell shape change and cytoskeleton reorganization. Aim 2: To determine the role of nitric oxide synthase in substance P mediated response to injury by endothelial cells. We will determine whether substance P signaling pathways leading to nerve growth factor, vascular endothelial growth factor and interleukin 8 synthesis depend on nitric oxide. Aim 3: To determine which endothelial cell derived mediators regulate nerve cell sprouting. We will evaluate the second limb of our hypothesis by identifying endothelial cell-derived neurotrophins that regulate sensory nerve fiber sprouting. Using an in vitro model of nerve growth, we will verify that the manipulations in aims 1 and 2 diminish soluble mediators that are responsible for nerve differentiation. Aim 4: To determine how neuropeptide activity in transgenic mice and mutant diabetic mice alters response to injury. We will determine how substance P modulates cutaneous response to injury using an excisional wound model in normal mice, in diabetic mice and in mice with targeted disruption of neuronal nitric oxide synthase, inducible nitric oxide synthase or endothelial nitric oxide synthase.