Redox Control of Wound Healing

伤口愈合的氧化还原控制

• 批准号: 6818478
• 负责人: Chandan K Sen
• 金额: $ 27.66万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6818478
• 关键词: NAD(P)H dehydrogenase; angiogenesis; antisense nucleic acid; biological signal transduction; confocal scanning microscopy; electrochemistry; electron spin resonance spectroscopy; enzyme activity; focal adhesion kinase; gene environment interaction; gene expression; genetically modified animals; growth factor receptors; immunocytochemistry; immunoprecipitation; laboratory mouse; microarray technology; oxidation reduction reaction; tissue /cell culture; transfection; vascular endothelial growth factors; vascular endothelium; wound healing

DESCRIPTION (provided by applicant): Compromised wound tissue oxygenation has been long recognized as a key limiting factor in healing. Oxygen homeostasis has therefore been the center of major attention in wound healing research. Current findings indicate that a significant fraction of oxygen at the wound site is utilized to generate reactive oxygen species (ROS). ROS are classically described as accidental metabolic by-products, and are generally thought to be deleterious. The phagocyte NADPH oxidase deliberately generates ROS in transient bursts to kill pathogens. High concentrations of H2O2 (equal to or more than 1%) are used clinically for wound disinfection. However, there is a general agreement that at these doses H2O2 is harsh to regenerating cells and may not benefit overall healing. The recent discovery of another family of NADPH oxidases, the Nox/Duox family, provides additional examples of deliberate generation of ROS by non-phagocytic cells at the wound site. Upon induction, these cells generate low-levels of ROS on a sustained basis. Recent data support that such low concentration of ROS can regulate specific key redox-sensitive signaling processes most of which can be directly linked to wound healing. This proposal rests on our striking observation that genetic as well as pharmacological approaches to deliver low concentrations of ROS promote dermal wound angiogenesis, contraction and closure. Such low concentrations of ROS did not influence wound infection status. Strategies to decompose ROS at the wound site impaired healing. Taken together, these observations led to the hypothesis that resisting infection is not the sole role of ROS at the wound-site, and that ROS drives redox-signaling to support healing. Indeed, congenital defect in human NADPH oxidase results in impaired wound healing and antibiotics alone cannot correct such defect. We have observed that NADPH oxidase deficient transgenic mice suffer from impaired dermal healing even under infection-free conditions; the impairment is corrected by low-dose ROS delivery. Our working hypothesis is that ROS generated by wound-related cells (low-ROS by Nox; and residual ROS in the aftermath of phagocyte respiratory burst) support earlyphase acute wound healing by inducing redox-sensitive signal transduction pathways. Our long-term objective is to understand this new aspect of wound tissue oxygen homeostasis. We seek to illuminate the significance of redoxsensitive processes in wound healing, and to design redox-based strategies to promote healing. To test the stated hypothesis we propose the following three specific aims using standard models of murine acute dermal wound and in vitro culture of dermal microvascular endothelial cells: Aim 1. Investigate the role of ROS in excisional dermal wound vascularization, contraction and repair; Aim 2. Determine the significance of NADPH oxidases at the wound site; and Aim 3. Characterize the redox-sensitive mechanisms that regulate wound angiogenesis.

描述（由申请人提供）： 伤口组织氧合作用受损一直被认为是愈合的关键限制因素。因此，氧稳态一直是伤口愈合研究的主要关注中心。目前的研究结果表明，伤口部位的大部分氧气被用来产生活性氧（ROS）。 ROS 通常被描述为偶然的代谢副产物，通常被认为是有害的。吞噬细胞 NADPH 氧化酶故意在瞬时爆发中产生 ROS 以杀死病原体。临床上多采用高浓度H2O2（等于或大于1%）进行伤口消毒。然而，人们普遍认为，在这些剂量下，H2O2 对再生细胞不利，可能无助于整体愈合。最近发现的另一个 NADPH 氧化酶家族（Nox/Duox 家族）提供了伤口部位非吞噬细胞有意产生 ROS 的更多例子。诱导后，这些细胞持续产生低水平的 ROS。最近的数据表明，如此低浓度的活性氧可以调节特定的关键氧化还原敏感信号传导过程，其中大部分可以直接与伤口愈合相关。该提议基于我们惊人的观察结果，即传递低浓度 ROS 的遗传和药理学方法可促进真皮伤口血管生成、收缩和闭合。如此低浓度的 ROS 并不影响伤口感染状态。在伤口部位分解 ROS 的策略会损害愈合。综上所述，这些观察结果得出这样的假设：抵抗感染并不是 ROS 在伤口部位的唯一作用，并且 ROS 驱动氧化还原信号以支持愈合。事实上，人类 NADPH 氧化酶的先天性缺陷会导致伤口愈合受损，仅靠抗生素无法纠正这种缺陷。我们观察到，NADPH 氧化酶缺陷的转基因小鼠即使在无感染的条件下也会出现真皮愈合受损的情况；这种损伤可以通过低剂量 ROS 输送来纠正。我们的工作假设是，伤口相关细胞产生的 ROS（Nox 产生的低 ROS；以及吞噬细胞呼吸爆发后残留的 ROS）通过诱导氧化还原敏感的信号转导途径支持早期急性伤口愈合。我们的长期目标是了解伤口组织氧稳态的这一新方面。我们试图阐明氧化还原敏感过程在伤口愈合中的重要性，并设计基于氧化还原的策略来促进愈合。为了检验上述假设，我们使用小鼠急性真皮伤口标准模型和真皮微血管内皮细胞体外培养提出以下三个具体目标： 目的 1. 研究 ROS 在切除真皮伤口血管化、收缩和修复中的作用；目标 2. 确定 NADPH 氧化酶在伤口部位的重要性；目标 3. 表征调节伤口血管生成的氧化还原敏感机制。