Role of TLR2 in angiogenesis

摘要。 先天免疫和Toll样受体（TLR）在血管发育和新生血管形成中的临床重要性 疾病，和发现新的内源性TLRs配体产生的脂质氧化和扩大 在人类病理学中的功能强调了TLR（特别是TLR 2）在心血管和肺疾病中的重要性。 与炎症相关的疾病和血管病变，例如老化和糖尿病的视网膜疾病。 TLR 2表达不限于免疫系统;它在其他细胞上起作用，包括内皮细胞和巨噬细胞。 可以被细菌和内源性配体，即脂质过氧化产物激活。的知识 对内皮TLR 2的研究仅限于使用抑制剂或普遍存在的TLR 2 KO的研究。因此，我们建议设立 内皮细胞TLR 2在新生血管生成中的作用，使用出生后和发育模型。我们会测试的 内皮细胞TLR 2通过两种机制调节血管生成：直接通过整合素介导的迁移， 间接地通过促进骨髓细胞的募集。TLR 2依赖性血管生成在肿瘤细胞中增强。 存在外源性细菌TLR 2配体以及内源性TLR 2配体，即CEP，特别是在 其内源性配体高度普遍存在的组织（即视网膜）。我们的具体目标是：目标1。以限定 通过使用内皮特异性（Cdh 5-CreERT）KO小鼠， 出生后（伤口、肿瘤）模型和发育（视网膜）血管生成。目标2.为了评估TLR 2的作用， 在血管生成中依赖骨髓细胞募集。为了确定EC TLR 2的作用， 在出生后和发育期间骨髓细胞募集中使用KO（CX 3CR 1-CreERT）的骨髓TLR 2 血管生成目标3：确定内源性和外源性TLR 2激活的促血管生成途径 内皮细胞中的配体。本文将对TLR 2/CD 36复合物的调控功能和机制进行阐述。 TLR 2/Myd 88/TIRAP/IRAK 3/4/TRAF 6和Src家族激酶在促血管生成整合素调节中的作用 将建立功能，即活化、粘附和迁移。EC新TLR 2途径的主要靶点 将使用新型试剂在体内验证生物学，例如TRAF 6。这些研究将首次建立一个 内皮TLR 2在血管生成中的直接作用，并将连接先天免疫和血管形成，特别是在 与感染、炎症和氧化应激相关并加剧的病理学。

ABSTRACT. Emerging clinical importance of innate immunity and Toll-like receptors (TLRs) in vascular development and diseases, and discoveries of new endogenous TLRs ligands generated by lipid oxidation and their expanding functions in human pathologies underscore importance of TLRs (TLR2 in particular) in cardiovascular and lung diseases and vascular pathologies associated with inflammation, such as retinal diseases of aging and diabetes. TLR2 expression is not restricted to immune system; it is functional on other cells, including endothelium and can be activated by bacterial and endogenous ligands, i.e. products of lipid peroxidation. The knowledge of endothelial TLR2 is limited to studies with inhibitors or ubiquitous TLR2 KO. Accordingly, we propose to establish a role for endothelial TLR2 in angiogenesis using postnatal and developmental models. We will test that endothelial TLR2 regulates angiogenesis by two mechanisms: directly by integrin-mediated migration and indirectly, by promoting recruitment of myeloid cells. TLR2-dependent angiogenesis is augmented in the presence of exogenous bacterial TLR2 ligands as well as endogenous TLR2 ligands, i.e. CEP, especially in tissues where its endogenous ligand is highly prevalent (i.e. in retinas). Our specific Aims are: Aim 1. To define the cell autonomous function of TLR2 on endothelium by using endothelial-specific (Cdh5-CreERT) KO mice in postnatal (wound, tumors) models and developmental (retinal) angiogenesis. Aim 2. To assess the role of TLR2- dependent myeloid cells recruitment in angiogenesis. To establish the role of EC TLR2 as we as the role of myeloid TLR2 using KO (CX3CR1-CreERT) in myeloid cells recruitment during postnatal and developmental angiogenesis. Aim 3. To define the proangiogenic pathways activated by endogenous and exogenousTLR2 ligands in endothelial cells. The regulatory function and mechanism of TLR2/CD36 complex will be addressed. Role for TLR2/Myd88/TIRAP/IRAK3/4/TRAF6 and Src family kinases in regulation of proangiogenic integrin functions, i.e. activation, adhesion and migration will be established. Main targets of TLR2 pathway novel to EC biology, e.g. TRAF6 will be verified in vivo using novel reagents. These studies will establish for the first time a direct role of endothelial TLR2 in angiogenesis and will link innate immunity and vascularization, especially in pathologies associated and exacerbated by infection, inflammation and oxidative stress.