Regulatory gene-chemokine networks in the formation of hemodialysis AVF stenosis

总结/摘要： 静脉狭窄（VS）和新生内膜增生（VNH）经常发生在动静脉瘘（AVF）中， 经皮腔内血管成形术（PTA），导致终末期血液透析（HD）的AVF血流减少， 晚期肾病（ESRD）患者。本次更新的长期目标是：1。定义VS PTA后AVF发生VNH; 2.开发新的药物疗法以减轻AVF中的VS/VNH 在啮齿动物/猪模型中进行PTA后，用于未来的临床试验。 2016年，726，331名美国患者（全球约200万）被诊断患有ESRD，发病率每年上升3%。 大约87%的ESRD患者接受HD肾脏替代治疗。最佳长期HD需要 通过AVF或移植物的血管通路。AVF一年通畅率仅为62%，频繁重复血管成形术 维护费用> 30亿美元/年。血管成形术后AVF VS/VNH的机制尚不清楚。疗法 预防PTA后AVF失败的主要原因VS/VNH将减少发病率和医疗费用， 对ESRD患者有益。 在之前的研究中（3年，资金减少），我们研究了1，25（OH）2D 3- 将包被的纳米颗粒（1，25 NP）注入AVF流出静脉，以减少慢性肾病小鼠和猪的VNH （CKD）。我们发现用1，25 NP处理AVF可降低AVF的VNH和VS，巨噬细胞的数量， 平滑肌细胞（SMC）和成纤维细胞，立即早期反应基因（Iex-1/Ier 3）表达和细胞 增殖，导致较少的流出静脉纤维化。本提案检查PTA后AVF失败的病理生理学 没有有效的治疗方法。最近使用紫杉醇涂层技术的试验产生了混合结果- 由于使用这些药物治疗的患者的全因死亡率增加， 用于外周动脉疾病症状的器械。 需要基于机械观察的新疗法来预防PTA后的VS/VNH。作为回应，我们 开发了患有PTA治疗的狭窄AVF的CKD小鼠和猪模型，并获得了建立 Ier 3/Iex-1的核心作用， 单核细胞趋化蛋白-1（Mcp-1/Ccl 2）驱动的细胞浸润 AVF VS的发病机制。PTA后向狭窄静脉外膜输送1，25 NP可降低AVF患者的VS和VNH。 我们模型中的AVF。本申请检查了PTA后VS/VNH的机制，测试了1，25 NP的疗效 在鼠和猪模型中进行进一步的临床试验。 中心假设：血管成形术后用外膜1，25 NP治疗狭窄的流出静脉将减少SMC Ier 3和随后的Mcp-1/Ccl 2表达以及单核细胞和巨噬细胞对血管壁的浸润， 更少的VS和VNH。为了验证这一假设，我们提出了两个目标： 目的1：探讨SMC Ier 3基因缺失和Mcp-1/Ccl 2基因敲低对鼠动静脉瘘PTA后VS/VNH的影响。 目的2：确定1，25 NP降低啮齿动物PTA后AVF VS/VNH的作用机制和效果， CKD的猪模型。

SUMMARY/ABSTRACT: Venous stenosis (VS) and neointimal hyperplasia (VNH) often occur in arteriovenous fistulas (AVFs) after percutaneous transluminal angioplasty (PTA), leading to reduced AVF blood flow for hemodialysis (HD) in end- stage renal disease (ESRD) patients. This renewal's long-term goals are to: 1. Define mechanisms by which VS and VNH occur in AVFs after PTA; and 2. Develop new pharmacologic therapies to attenuate VS/VNH in AVFs after PTA in rodent/porcine models for a future clinical trial. In 2016, 726,331 US patients (~2M globally) were diagnosed with ESRD, with an annual 3% rising incidence. Roughly 87% of ESRD patients undergo renal replacement therapy with HD. Optimal long-term HD necessitates vascular access via AVFs or grafts. One year AVF patency rate is only 62%, with frequently repeated angioplasty maintenance at >$3B/yr. The mechanisms underpinning AVF VS/VNH after angioplasty are unknown. Therapies preventing VS/VNH, the major cause of AVF failure after PTA, will reduce morbidity and healthcare costs, of huge benefit to patients with ESRD. In the prior award (with 3 years and reduced funding), we studied the efficacy of adventitial delivery of 1,25(OH)2D3- coated nanoparticles (1,25 NP) to the AVF outflow vein to reduce VNH in mice and pigs with chronic kidney disease (CKD). We showed treatment of AVFs with 1,25 NP reduces VNH and VS of AVFs, the number of macrophages, smooth muscle cells (SMC) and fibroblasts, immediate early response gene (Iex-1/Ier3) expression and cellular proliferation, leads to less outflow vein fibrosis. This proposal examines AVF failure pathophysiology following PTA for which no effective therapies exist. Recent trials using paclitaxel coated technologies yielded mixed results— clinical practice adoption has been diminished due to increased all-cause mortality in patients treated with these devices for peripheral arterial disease symptoms. New therapies based on mechanistic observations are needed to prevent VS/VNH after PTA. In response, we developed murine and porcine models of CKD with stenotic AVFs treated with PTA and obtained data establishing the central role of Ier3/Iex-1 and monocyte chemoattractant protein-1 (Mcp-1/Ccl2) driven cellular infiltration in the pathogenesis of AVF VS. Adventitial delivery of 1,25 NP to the stenotic vein after PTA reduced VS and VNH in AVFs in our models. This application examines the mechanism of VS/VNH following PTA, testing 1,25NP efficacy in both murine and porcine models for a future clinical trial. Central Hypothesis: Treatment of stenotic outflow veins after angioplasty with adventitial 1,25NP will reduce SMC Ier3 and subsequent Mcp-1/Ccl2 expression and vessel wall infiltration by monocytes and macrophages resulting in less VS and VNH. To test this hypothesis, we propose two aims: Aim 1: Assess the role(s) of SMC Ier3 deletion and Mcp-1/Ccl2 knockdown on VS/VNH after PTA of murine AVFs. Aim 2: Determine the mechanism of action and effect of 1,25 NP on reducing AVF VS/VNH after PTA in rodent and porcine models of CKD.