The Role of Hypoxia In Venous Neointimal Hyperplasia In Hemodialysis Grafts

缺氧在血液透析移植物静脉新生内膜增生中的作用

• 批准号: 9276718
• 负责人: Sanjay Misra
• 金额: $ 57.38万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-02-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9276718
• 关键词: Acute monocytic leukemia; Adipose tissue; Affect; Angioplasty; Antibodies; Area; Arteriovenous fistula; Blood Vessels; Cartoons; Cell Line; Cell Therapy; Cell Transplants; Cell physiology; Cells; Chronic Kidney Failure; Clinical; Clinical Trials; Coculture Techniques; Data; Data Aggregation; Dialysis Solutions; Dialysis patients; Dialysis procedure; End stage renal failure; Endothelium; Evaluation; Failure; Family suidae; Fistula; Funding; Future; Gene Expression; Goals; Grant; Hemodialysis; Hyperplasia; Hypoxia; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Intervention; Knock-out; Lead; Literature; Mesenchymal Stem Cells; Modeling; Monocyte Chemoattractant Protein-1; Mus; Outcome; PPAR gamma; Pathologic; Patient Care; Patients; Population; Publishing; Radiology Specialty; Renal Replacement Therapy; Research; Role; Secondary to; Staining method; Stenosis; Stents; Stress; TNF gene; Testing; Therapeutic; Time; Tissue Sample; Tissue Stains; Transplantation; Tunica Adventitia; United States; Up-Regulation; Vascular Endothelial Growth Factors; Vascular remodeling; Veins; Venous; bevacizumab; cytokine; design; experience; experimental study; genetic approach; improved; in vivo; macrophage; monocyte; mouse model; patient population; pre-clinical; programs; protein expression; small hairpin RNA; vascular smooth muscle cell proliferation

PROJECT SUMMARY/ABSTRACT: Nearly 600,000 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). Our preliminary data demonstrate that outflow veins treated with AMSCs plus bevacuzimab have a significant increase in lumen vessel area and a decrease in the ratio of neointima/media + adventitia compared to controls. This effect is associated with a reduction in PPAR-γ gene expression. Furthermore, we show that bevacuzimab localizes to the endothelium and not the adventitia where AMSCs are transplanted and thus will not disrupt AMSC function. VEGF-A staining of this tissue demonstrates a reduction in sub-endothelial VEGF- A where bevacuzimab is localized. We used THP-1 monocytes (cell line from acute monocytic leukemia patients) to simulate the in vivo findings of monocyte to macrophage differentiation under hypoxia, which shows that THP-1 monocytes differentiate to macrophages via an increase in PPAR-γ. When monocytes are co-cultured with AMSCs plus bevacuzimab and subjected to hypoxic stress, there is a decrease in differentiation to macrophages with a reduction in PPAR-γ gene expression compared to controls. In aggregate, these data support the following CENTRAL Hypothesis, which will be tested in the present revised competitive renewal: Adventitial transplantation of AMSCs to the outflow vein of AVF combined with bevacuzimab therapy reduces PPAR-γ gene expression in monocytes leading to decreased macrophage differentiation and subsequent VNH formation. To test our hypothesis, we have developed three specific aims: SPECIFIC AIM 1: Evaluate the efficacy of AMSCs combined with bevacizumab on reducing VNH using murine and porcine models. Optimal bevacizumab combination with AMSCs will be determined in a murine model and next validated in a preclinical porcine model of AVF with CKD. The pathological and radiological evaluation will be carried out in the tissue samples to assess long-term patency and vascular remodeling. SPECIFIC AIM 2: Determine in vitro role(s) of AMSCs combined with bevacuzimab on reducing hypoxia-induced up-regulation of PPAR-γ in monocytes leading to a reduction in macrophage differentiation. Initially, the effect of hypoxia on expression of PPAR-γ in monocytes will be examined. Next, experiments will be conducted using co-culture with AMSCs to override the negative effect of PPAR-γ caused by hypoxia followed by administering bevacuzimab. The outcomes will include the expression of genes responsible for inflammation and vascular remodeling as well as cellular function. These results will be validated in tissue samples from Aim 1. SPECIFIC AIM 3: Assess in vivo role(s) of PPAR-γ using genetic approaches on VNH formation. We will use monocyte specific conditional knockout of PPAR-γ in mice with AVF and CKD and examine the effect on venous stenosis formation with gene and protein expression of pro-inflammatory cytokines. Next, we will determine the role(s) of bevacuzimab plus monocyte specific conditional knockout of PPAR-γ mice on VNH.

项目摘要/摘要： 美国有近60万名患者患有终末期肾病(ESRD)，预计这一人群将 在下一个十年翻一番。目前这项提案和研究计划的长期目标是改善 终末期肾病患者的护理，绝大多数患者使用长期血液透析作为其肾脏模式 替代疗法。这些患者需要高功能的血管通路才能获得最佳治疗效果。 充分性。血液透析血管通路失败多为静脉狭窄继发于新生血管内膜 增生症(VNH)。 我们的初步数据显示，用AMSCs和贝真空单抗联合治疗的流出静脉有 管腔血管面积显著增加，新生内膜/中膜+外膜比率降低。 到控制程序。这种作用与PPAR-γ基因表达的减少有关。此外，我们证明了 BVacuzimab定位于内皮细胞，而不是移植AMSCs的外膜，因此将 不会中断AMSC的功能。血管内皮生长因子-A染色显示，亚内皮下血管内皮生长因子-A减少。 A其中，beVacuzimab是局部化的。我们使用THP-1单核细胞(来自急性单核细胞白血病的细胞系 患者)模拟体内低氧条件下单核细胞向巨噬细胞分化的结果， 结果显示，Thp-1单核细胞通过增加PPAR-γ向巨噬细胞分化。当单核细胞 与AMSCs联合培养后，在低氧应激条件下， 与对照组相比，PPAR-γ基因表达降低，向巨噬细胞分化。在……里面 总体而言，这些数据支持以下中心假设，该假设将在本订正本中得到检验 竞争性更新：将AMSCs外膜移植到动静脉流出道联合 贝真空单抗治疗降低单核细胞PPAR-γ基因表达导致巨噬细胞减少 分化和随后的VNH形成。为了验证我们的假设，我们制定了三个具体目标： 特异性目标1：用小鼠评价AMSCs联合贝伐单抗降低VNH的效果 还有猪模特。贝伐单抗与AMSCs的最佳组合将在小鼠模型中确定，并 接下来，在临床前Avf合并CKD的猪模型中进行了验证。病理和放射学评估将 在组织样本中进行，以评估长期通畅和血管重塑。 特异性目的2：体外检测骨髓间充质干细胞联合贝真空单抗对缺氧诱导的保护作用(S) 单核细胞中PPAR-γ的上调导致巨噬细胞分化的减少。最初，这种效果 低氧对单核细胞PPAR-γ表达的影响。接下来，将使用以下工具进行实验 与AMSCs共培养可拮抗缺氧后给药引起的PPAR-γ负性效应 是真空单抗。结果将包括炎症和血管相关基因的表达。 重塑和细胞功能。这些结果将在AIM 1的组织样本中得到验证。 具体目的3：用遗传学方法评估PPAR-γ在体内对vnh形成的作用(S)。我们将使用 PPAR-γ单核细胞特异性条件性敲除对动静脉曲张和慢性肾功能不全小鼠的影响 静脉狭窄形成与促炎细胞因子的基因和蛋白表达有关。接下来，我们将 确定贝真空单抗加单核细胞特异性条件性敲除PPAR-γ小鼠对vnH的作用(S)。