The Role of Hypoxia In Venous Neointimal Hyperplasia In Hemodialysis Grafts

描述（由申请人提供）： 项目描述：美国有超过400，000名患者患有终末期肾病（ESRD），预计未来十年人口将翻一番。本提案和研究项目的长期目标是改善ESRD患者的护理，绝大多数患者使用长期血液透析作为肾脏替代治疗模式。这些患者需要高功能的血管通路以获得最佳治疗充分性。血液透析血管通路失败通常是由于继发于新生内膜增生（VNH）的静脉狭窄。我们的研究的初步数据表明，几种机制可能是负责VNH的形成。其中包括：1）升高的缺氧诱导因子-1 α（HIF-11），然后刺激; 2）血管内皮生长因子-A（VEGF-A）及其受体的表达增加; 3）基质金属蛋白酶-2（MMP-2）和MMP-9（明胶酶）的表达增加;和4）成纤维细胞从外膜和中膜增殖和迁移到内膜，导致VNH形成。我们已经开发了最先进的分子试剂，并验证了小鼠肾切除术与动静脉瘘模型（AVF）和缺氧成纤维细胞培养模型。体外和体内模型以及伴随的试剂使我们能够严格检验我们的中心假设：当HIF-11增加刺激外膜成纤维细胞分化为肌成纤维细胞（1-SMA阳性细胞）时，发生静脉新生内膜增生。HIF-11调节的蛋白包括VEGF-A、MMP-2和MMP-9的表达增加导致肌成纤维细胞增殖和迁移到内膜中，从而导致VNH的形成。为了检验我们的中心假设，我们制定了三个具体目标：1）。确定VEGF-A在VNH中的时间和空间作用。2）。确定MMPs在VNH中的作用和调节。3）。确定缺氧诱导成纤维细胞向肌成纤维细胞分化的分子机制是否通过VEGF-A/MMP轴介导。这些目标的成功完成将使我们能够最终将旨在抑制VNH的疗法转化为临床试验，从而使用可使用基于导管的技术递送的市售抗VEGF-A抗体（阿瓦斯丁（贝伐单抗））和MMP抑制剂（辛伐他汀或西罗莫司）改善患者结果。

DESCRIPTION (provided by applicant): Project description: More than 400,000 patients in the US have end stage renal disease (ESRD), a population expected to double in the next decade. The long term goal of this current proposal and research program is to improve the care of patients with ESRD, the vast majority of who use long-term hemodialysis as their mode of renal replacement therapy. These patients require highly functioning vascular access for optimal therapeutic adequacy. Hemodialysis vascular access failure is frequently from venous stenosis secondary to neointimal hyperplasia (VNH). Preliminary data from our studies indicate that several mechanisms may be responsible for VNH formation. These include: 1) Elevated hypoxia inducible factor-1 alpha (HIF-11) which then stimulates; 2) Increased expression of vascular endothelial growth factor-A (VEGF-A) and its receptors; 3) Increased expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 (gelatinases); and 4) Proliferation and migration of fibroblasts from the adventitia and media to the intima resulting in VNH formation. We have developed state- of-the art molecular reagents and validated mouse nephrectomy with arteriovenous fistula model (AVF) and a hypoxia fibroblast cell culture model. The in vitro and in vivo models and accompanying reagents allow us to rigorously test our Central Hypothesis: Venous neointimal hyperplasia occurs when increased HIF-11 stimulates adventitial fibroblasts to differentiate into myofibroblasts (1-SMA positive cells). Increased expression of HIF-11 regulated proteins including VEGF-A, MMP-2 and MMP-9 results in the proliferation and migration of myofibroblasts into the intima leading to the formation of VNH. To test our central hypothesis we have developed three specific aims: 1). Determine the temporal and spatial role(s) of VEGF-A in VNH. 2). Determine the role(s) and regulation of MMPs in VNH. 3). Determine if the molecular mechanism of hypoxia induced fibroblast to myofibroblast differentiation is mediated by the VEGF- A/MMP axes. Successful completion of these aims will allow us to ultimately translate therapies aimed at inhibiting VNH to clinical trials thereby improving patient outcomes using commercially available anti-VEGF-A antibodies (Avastin (Bevacizumab)) and MMP inhibitors (Simvastatin or Sirolimus) which can be delivered using catheter based technology.