Inflammation and Repair as Determinants of Hemodialysis Fistula Maturation

描述（由申请人提供）：目前的估计表明，大约一半的动静脉内瘘（AVF）在手术创建后6个月内未能功能成熟并可定期用于血液透析。成熟的过程（及其失败）知之甚少，目前还没有有效的治疗方法来促进成熟。一项NIDDK申办的“血液透析瘘管成熟（HFM）"（U 01 DK-082189-01）队列研究正在进行中，旨在检查接受AVF置入的患者中广泛的临床、人口统计学、生理学和护理过程变量是否影响AVF的成熟和透析可用性。虽然母研究将术前血管功能和静脉组织学特征与术后超声数据相关联，但其主要的全球评估将无法提供决定AVF成熟的局部和特定生物学机制的详细信息。因此，拟定的辅助临床研究检查了既存内皮和平滑肌细胞功能障碍、内皮修复和全身炎症之间的复杂相互作用。具体目标是：（1）在AVF形成时，描绘供体静脉壁内内皮细胞和平滑肌细胞的全基因组表达模式，并鉴定独特的基因组模式（即“信号”），其与AVF外向重塑和血流速率的变化相关，（2）确定静脉移植物植入后内皮损伤和修复之间的初始和持续平衡，如循环内皮细胞（CEC）和内皮祖细胞（EPCs）所定义的，并获得与成功或不成功的AVF成熟相关的EPCs的新的基因组“特征”，和（3）评估全身性炎症的作用，如循环单核细胞的全基因组表达模式所确定的，因为它们与AVF成熟相关，并可用于预测结果和鉴定新的途径。我们计划在佛罗里达大学入组100例患者（50例患者试验集，50例患者验证集），这些患者将参与母研究。我们建议采用激光显微切割捕获静脉壁内的内皮细胞和平滑肌细胞，以及用于术前和术后第14天获得的血液EPCs和单核细胞的宏观尺度和新型微流体捕获技术，用于随后的全基因组表达分析，使用新型专有的Affytron HH/2外显子阵列。使用这些新技术，我们将实现两个主要目标：（1）从血管组织细胞群和富集的血液白细胞中开发新的基因组特征，可用于预测成功的结果，以及（2）开发新的见解新的信号通路和潜在的治疗干预机制。 拟议的研究将有效利用母HFM研究中独特的数据收集工作，并增加结果的预测基因组建模以及对AVF发育的生理学和病理生理学的重要机制见解。 公共卫生相关性：大约一半的动静脉内瘘将无法实现功能成熟并可用于血液透析。这项NIDDK申办的“血液透析瘘管成熟（HFM）"（U 01 DK-082189-01）队列研究的辅助研究将检查移植物形成前后血液单核细胞和内皮前体细胞以及静脉移植物本身的全基因组表达模式。总体目标是生成移植成功的预后指标，并对移植失败的原因提出新的机制见解。

DESCRIPTION (provided by applicant): Current estimates suggest that approximately half of arteriovenous fistulas (AVF) fail to functionally mature and become regularly usable for hemodialysis by six months of surgical creation. The process of maturation (and its failure) is poorly understood, and no effective therapies to promote maturation are currently known. An NIDDK-sponsored "Hemodialysis Fistula Maturation (HFM)"(U01 DK-082189-01) cohort study is underway to examine whether a broad range of clinical, demographic, physiological and process-of-care variables in patients undergoing AVF placement influence maturation and usability of the AVF for dialysis. While the parent study will correlate pre-operative vascular function and venous histological features with post-operative ultrasound data, its largely global assessments will not furnish a detailed picture of the local and specific biological mechanisms that determine AVF maturation. Hence, the proposed ancillary clinical study examine the complex interplay between pre-existing endothelial and smooth muscle cell dysfunction, endothelial repair, and systemic inflammation. The specific objectives are (1) to delineate genome-wide expression patterns from endothelial and smooth muscle cells within the donor vein wall at the time of AVF creation, and to identify unique genomic patterns (i.e. "signatures") that are associated with AVF outward remodeling and changes in blood flow rate, (2) to determine the initial and ongoing balance between endothelial injury and repair following vein graft implantation, as defined by circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs), and obtain novel genomic "signatures" of EPCs associated with a successful or unsuccessful AVF maturation, and, (3) to evaluate the role of systemic inflammation, as determined by genome-wide expression patterns of circulating monocytes, as they relate to AVF maturation and can be used to predict outcomes and identify novel pathways. We propose to enter 100 patients (50 patient test set, 50 patient validation set) at the University of Florida who will participate in the parent study. We propose to employ laser microdissection for endothelial and smooth muscle cell capture within the vein wall, as well as macro-scale and novel microfluidic capture technologies for blood EPCs and monocytes obtained preoperatively and on post-op day 14 for subsequent genome-wide expression analysis using a novel proprietary Affymetrix HH/2 exon array. Using these novel technologies, we will accomplish two major goals: (1) develop novel genomic signatures from vascular tissue cell populations and enriched blood leukocytes that can be used to predict a successful outcome, and (2) develop new insights into novel signaling pathways and potential mechanisms for therapeutic intervention. The proposed studies will effectively exploit the unique data collection effort in the parent HFM study and add both predictive genomic modeling of outcome, and significant mechanistic insight into the physiology and pathophysiology of AVF development. PUBLIC HEALTH RELEVANCE: Approximately half of all arteriovenous fistulas will fail to functionally mature and become usable for hemodialysis. This ancillary study to an NIDDK-sponsored "Hemodialysis Fistula Maturation (HFM)"(U01 DK-082189-01) cohort study will examine genome wide expression patterns in blood monocytes and endothelial precursor cells prior to and after graft creation, as well as from the vein graft itself. The overall goal is to generate prognostic indicators of graft success and develop new mechanistic insights into the causes of graft failure.