Role(s) of VEGF in Resolution of Inflammation

描述（由申请人提供）：炎症是正常伤口修复的关键过程。在受伤时，细胞因子被激活并将白细胞（包括巨噬细胞）吸引到伤口部位。巨噬细胞是肉芽组织正常形成的关键，因为它们能清除伤口中的死细胞，并产生大量细胞因子，启动愈合组织的形成。虽然许多涉及炎症早期的详细机制是已知的，但涉及炎症消退的机制却知之甚少。了解炎症如何结束与了解它的开始同样重要，因为炎症的延长会导致愈合受损和慢性炎症状况。VEGF是伤口愈合的关键因素，主要以其在血管生成中的作用而闻名。然而，最近VEGF作为免疫和炎症的调节因子出现。我们已经发现，在伤口愈合过程中，VEGF有助于巨噬细胞诱导的炎症的消退，并在培养中刺激巨噬细胞的凋亡。我们还发现VEGF刺激人巨噬细胞中TNFSF14/LIGHT的表达。LIGHT是TNF超家族细胞因子的一员，已知在粘膜肿瘤中调节T细胞的共刺激和细胞凋亡。我们的发现指出了一种新的细胞因子调节途径参与炎症反应的解决。在这里提出的工作中，我们解决了这些新发现的VEGF在伤口愈合过程中解决炎症的功能的后果。我们假设VEGF在愈合过程中的新功能是调节受损组织中巨噬细胞的存活，而LIGHT是这一过程的关键介质。具体而言，我们将：(1)确定VEGF是否在体内诱导巨噬细胞凋亡，并在愈合过程中刺激LIGHT表达；(2)确定VEGF诱导的巨噬细胞死亡与LIGHT的关系。我们将使用培养的人巨噬细胞、正常小鼠和转基因小鼠的组合，结合VEGF和光依赖途径的激动剂/拮抗剂。将使用组织化学和免疫学技术、ELISA、多重RT-PCR和siRNA技术。这项工作是新颖的，因为它揭示了VEGF以前未知的功能，它很重要，因为它可能促进新疗法的发展，治疗愈合不良的伤口，以及其他以过度炎症为特征的疾病，以及VEGF上调的肿瘤。由于在大多数异常愈合情况下，炎症的消退很差或根本不发生，因此这条研究路线对健康具有重要意义，因为它确定了改善受损愈合的新策略，这是一个关键的医学领域。公共卫生相关性：炎症是正常伤口修复的关键过程。在受伤时，细胞因子被激活并将白细胞（包括巨噬细胞）吸引到伤口部位。巨噬细胞是肉芽组织正常形成的关键，因为它们能清除伤口中的死细胞，并产生大量细胞因子，启动愈合组织的形成。了解炎症如何结束与了解它的开始同样重要，因为炎症的延长会导致愈合受损和慢性炎症状况。我们已经发现，在伤口愈合过程中，VEGF有助于解决巨噬细胞诱导的炎症，并刺激巨噬细胞死亡。这里提出的研究是为了测试VEGF在炎症消退中发挥作用的可能性，以及LIGHT介导VEGF在炎症消退中的作用。由于在大多数异常愈合情况下，炎症的消退很差或根本没有，因此这条研究路线对健康具有重要意义，因为它确定了改善受损愈合的潜在新策略，这是一个关键的医学领域。

DESCRIPTION (provided by applicant): Inflammation is a key process in normal wound repair. Upon wounding, cytokines are activated and chemoattract leukocytes, including macrophages, to the wound site. Macrophages are key for the proper formation of granulation tissue because they clean up dead cells in the wound and produce a plethora of cytokines that initiate formation of the healing tissue. While many detailed mechanisms involved early in inflammation are known, those involved in resolution of inflammation are poorly understood. Understanding how inflammation ends is as important as understanding its beginning because prolongation of inflammation leads to impaired healing and chronic inflammatory conditions. VEGF is a key factor in wound healing and is primarily known for its role in angiogenesis. However, recently VEGF is emerging as a regulator of immunity and inflammation. We have discovered that VEGF contributes to resolution of macrophage- induced inflammation during wound healing and that it stimulates macrophage apoptosis in culture. We have also shown that VEGF stimulates the expression of TNFSF14/LIGHT in human macrophages. LIGHT is a member of the TNF superfamily of cytokines known to regulate co-stimulation of T cells as well as apoptosis in mucosal tumors. Our findings point to a novel cytokine-modulated pathway involved in resolution of the inflammatory response. In the work proposed here we address the consequences of these newly discovered functions of VEGF in resolution of inflammation during wound healing. We hypothesize that a novel function of VEGF in the healing process is modulation of macrophage survival in the damaged tissue and that LIGHT is a critical mediator of this process. Specifically, we will: (1) Determine whether VEGF induces macrophage apoptosis in vivo and stimulates LIGHT expression during healing and (2) Determine the relationship between VEGF-induced macrophage cell death and LIGHT. We will use a combination of cultured human macrophages, normal and genetically-modified mice, coupled with agonists/antagonists of VEGF- and LIGHT-dependant pathways. Histochemical and immunological techniques, ELISA, multiplex RT-PCR and siRNA technology will be used. The work proposed is novel because it reveals previously unknown functions of VEGF and it is important because it may facilitate the development of new therapies for poorly-healing wounds as well as other conditions characterized by excessive inflammation and for tumors in which VEGF is upregulated. Because resolution of inflammation occurs poorly or not at all in most abnormal healing situations, this line of investigation is significant for health because it identifies a novel strategy for improving impaired healing, a critical medical area. PUBLIC HEALTH RELEVANCE: Inflammation is a key process in normal wound repair. Upon wounding, cytokines are activated and chemoattract leukocytes, including macrophages, to the wound site. Macrophages are key for the proper formation of granulation tissue because they clean up dead cells in the wound and produce a plethora of cytokines that initiate formation of the healing tissue. Understanding how inflammation ends is as important as understanding its beginning because prolongation of inflammation leads to impaired healing and chronic inflammatory conditions. We have discovered that VEGF contributes to resolution of macrophage-induced inflammation during wound healing and that it stimulates macrophage death. The studies proposed here are to test the possibility that VEGF is a player in resolution of inflammation and that LIGHT mediates the VEGF effects on resolution of inflammation. Because resolution of inflammation occurs poorly or not at all in most abnormal healing situations, this line of investigation is significant for heath because it identifies a potentially novel strategy for improving impaired healing, a critical medical area.