The Role of Hydrogen Peroxide in RAGE Expression in Collateral Vessel Formation

 描述(申请人提供)：冠状动脉和外周血管疾病都是日益严重的健康问题，可能导致血液流动障碍和组织缺血，尽管新生血管和侧支血管的生长可以帮助恢复血液流动和保护组织，从而改善预后。侧支循环的形成包括血管生成和动脉生成，是一个复杂的过程，有许多协调部分，包括炎症信号和细胞的增殖和迁移。这些炎症反应的平衡很重要，因为太少或太多都会损害血管的生长。晚期糖基化终产物受体(RAGE)是与侧支循环生长的负面影响相关的一个因素，可能加剧炎症信号的负面影响；然而，其在缺血区的细胞来源和调节机制尚未完全清楚。初步数据显示，在缺血模型中，过氧化氢(H_2O_2)介导的RAGE表达增加，在非糖尿病状态下，RAGE对侧支循环形成有负面影响。我们假设卫星细胞是缺血时RAGE的主要来源，RAGE的表达是由过氧化氢介导的。为了验证这一假设，我们计划使用体内和体外模型。目的1将使用小鼠后肢缺血(HLI)模型来证实是否增加RAGE的表达是对过氧化氢的反应，并确认卫星细胞表达RAGE是对过氧化氢的反应。这一目标还将研究过氧化氢介导RAGE表达的机制。在目标2中，我们将研究野生型和RAGE基因敲除卫星细胞中介导侧枝生长的几种因子产生的差异。不同类型的细胞对细胞迁移和增殖的影响也将被研究。最后，在目标3中，我们将使用卫星细胞特异性过表达过氧化氢酶A的转基因小鼠(TgCat-PAX7)来研究H_2O_2介导的RAGE在卫星细胞中的特定作用。这些研究将促进对RAGE的作用及其调控的理解。了解RAGE在非糖尿病缺血中的表达是如何调节的，以及在缺血环境中RAGE的细胞来源是什么，这是至关重要的，因为操纵其调节可以帮助改善侧支循环的形成，改善缺血性疾病患者的血流和临床预后。

 DESCRIPTION (provided by applicant): Both coronary artery and peripheral vascular disease are growing health concerns that can lead to impaired blood flow and tissue ischemia, though neovascularization and growth of collateral vessels can help to restore blood flow and preserve the tissue improving outcomes. Collateral formation includes both angiogenesis and arteriogenesis and is a complex process with many coordinating parts including inflammatory signaling and cell proliferation and migration. The balance of these inflammatory responses is important since too little or too much can impair vessel growth. One factor that has been associated with negative effects on collateral growth and may exacerbate the negative effects of inflammatory signals is the receptor for advanced glycation end products (RAGE); however, the cellular source and the mechanism of its regulation in ischemic regions is not fully understood. The preliminary data show increases in RAGE expression mediated by hydrogen peroxide (H2O2) in an ischemia model and that RAGE has a negative effect on collateral formation in a non-diabetic state. We hypothesized that satellite cells are a major source of RAGE in ischemia and that RAGE expression is H2O2-mediated. To test this hypothesis we plan to use both in vivo and in vitro models. Aim 1 will use a mouse hind limb ischemia (HLI) model to confirm if increased RAGE expression is upregulated in response to H2O2 and confirm that satellite cells express RAGE in response to H2O2. This aim will also investigate the mechanisms by which H2O2 mediates RAGE expression. In Aim 2, we will investigate differences in the production of several factors that mediate collateral growth in wildtype and RAGE knockout satellite cells. The effects of the different cell types on cell migration and proliferation will be studied as well. Fially in Aim 3, we will study the specific role of H2O2-mediated RAGE expression in the satellite cells using a transgenic mouse with satellite cell specific overexpression of catalase a H2O2 scavenger (TgCat-pax7). These studies will advance the understanding of the role of RAGE and its regulation. It is critical to understand how RAGE expression is regulated in non-diabetic ischemia and what the cellular sources of RAGE are in the ischemic setting because manipulating its regulation could help improve collateral formation and improve blood flow and clinical outcomes for patients with ischemic disease.