The role of ARF6 in the progression of diabetic kidney disease

项目概述：大约40%的糖尿病患者会发展为糖尿病肾病（DKD）。不 它不仅是肾脏疾病的主要原因，而且还与患者发病风险增加有关， mortality.糖尿病环境引起足细胞、肾小球上皮细胞的应激和损伤，导致 蛋白尿和肾功能不全。因此，足细胞是决定DKD进展的关键靶细胞; 然而，我们对足细胞信号传导的有限理解限制了我们开发细胞特异性靶向 疗法我们最近发现，ARF 6（ADP-核糖基化因子6），一个小的GT3蛋白，参与了 足细胞对肾小球应激的反应和ARF 6的缺失可能对足细胞损伤具有保护作用， 某些肾损伤的案例本申请的总体目标是确定ARF 6在DKD中的作用 进展这一理由有两个方面。首先，在其他肾小球疾病模型中， 介导导致消失的信号通路（即在损伤的细胞中观察到的形态学适应）。 第二，我们的初步数据表明，高葡萄糖增加ARF 6活性。因此我们 假设高血糖增加了ARF 6活性，这有助于DKD的进展。本 最后，我们将利用体外糖尿病模型来确定ARF 6是否在足细胞消失，脱离， 和/或细胞死亡。我们还将确定ARF 6-GEFs（ARF 6-鸟嘌呤核苷酸交换因子）， ARF 6通过催化ARF 6-GDP转化为-GTP，参与消除、脱离和/或细胞死亡。使用糖尿病 在小鼠中，我们将特异性地从足细胞中删除ARF 6，并确定ARF 6在DKD中的作用。最后，我们将 探索药物干预：ARF 6和ARF 6-GEF抑制剂，以确定ARF 6抑制是否可以 预防或促进DKD进展。 职业发展计划：此申请的主要目的是支持林博士的职业发展 成为细胞信号和分子生物学领域的独立医生科学家。林医生向我求婚了 培训活动涉及四个领域：1）细胞生物学和信号传导，2）分子技术和基因组编辑，3） 糖尿病小鼠肾损伤模型，4）科学写作和口头报告。林博士已经组装了一个 由MD安德森癌症医院肾脏科主任Farhad Danesh博士领导的模范指导和咨询团队 中心（MDACC），在DKD和足细胞生物学领域的国家公认的专家，补充说， 由癌症生物学主席Raghu Kangui博士，分子和细胞肿瘤学主席Mien-Chie Hung博士， 博士伊丽莎白Shpall，干细胞移植和细胞治疗副主席，和博士大卫Tweardy， 内科主任。MDACC是尖端研究的卓越中心，将提供 为林博士提供了一个有利的、资源丰富的培训环境。

Project Summary: Approximately 40% of patients with diabetes will develop diabetic kidney disease (DKD). Not only is it the leading cause of renal disease, but it is also associated with increased risk of patient morbidity and mortality. The diabetic milieu causes stress and injury to podocytes, glomerular epithelial cells, resulting in proteinuria and renal dysfunction. Thus, podocytes are key target cells that determine DKD progression; however, our limited understanding of podocyte signaling restricts our ability to develop cell-specific targeted therapy. We recently identified that ARF6 (ADP-ribosylation factor 6), a small GTPase protein, is involved with podocyte response to glomerular stress and deletion of ARF6 might be protective against podocyte damage in certain cases of kidney injury. The overall objective of this application is to define the role of ARF6 in DKD progression. This rationale is two-fold. First, increased ARF6 activity in other glomerular disease models mediates signaling pathways that result in effacement (i.e. a morphological adaptation seen in injured podocytes), and second, our preliminary data suggests that high glucose increases ARF6 activity. Thus, we hypothesize that hyperglycemia increases ARF6 activity which contributes to the progression of DKD. To this end, we will utilize diabetic models in vitro to determine if ARF6 has a role in podocyte effacement, detachment, and/or cell death. We will also identify the ARF6-GEFs (ARF6-guanine nucleotide exchange factors) that activate ARF6 by catalyzing ARF6-GDP to -GTP involved in effacement, detachment, and/or cell death. Using diabetic mice, we will specifically delete ARF6 from podocytes and determine the role of ARF6 in DKD. Last, we will explore pharmacologic interventions: ARF6 and ARF6-GEF inhibitors, to determine if ARF6 inhibition can prevent or augment DKD progression. Career Development Plan: The primary objective of this application is to support Dr. Lin’s career development into an independent physician-scientist in the area of cell signaling and molecular biology. Dr. Lin’s proposed training activities are in four areas 1) cell biology and signaling, 2) molecular techniques and genome editing, 3) diabetic mouse models of kidney injury, 4) scientific writing and oral presentations. Dr. Lin has assembled an exemplary mentoring and advisory team led by Dr. Farhad Danesh, Chief of Nephrology at MD Anderson Cancer Center (MDACC), a nationally recognized expert in the field of DKD and podocyte cell biology, complemented by Dr. Raghu Kalluri, Chair of Cancer Biology, Dr. Mien-Chie Hung, Chair of Molecular and Cellular Oncology, Dr. Elizabeth Shpall, Deputy Chair of Stem Cell Transplantation and Cellular Therapy, and Dr. David Tweardy, Head of the Division of Internal Medicine. MDACC, a center of excellence in cutting edge research, will provide an opportune, resource abundant training environment for Dr. Lin.