TGF-beta Pathways that Protect Epithelia in Chronic Renal Injury

慢性肾损伤中保护上皮细胞的 TGF-β 通路

• 批准号: 9337599
• 负责人: Leslie S Gewin
• 金额: $ 35.55万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-13 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9337599
• 关键词: Acute Renal Failure with Renal Papillary Necrosis; Address; Adhesions; Affect; American; Angiotensins; Antioxidants; Apoptosis; Aristolochic Acids; Atrophic; Cell Culture Techniques; Cell Cycle; Cell Cycle Arrest; Cell Cycle Progression; Cell Differentiation process; Cell Survival; Cells; Chronic; Chronic Kidney Failure; Clinical Trials; Data; Economic Burden; Epithelial; Epithelial Cells; Epithelium; Etiology; Event; FDA approved; Fibrosis; Functional disorder; G1 Arrest; Genetic; Genetic Models; Growth; In Vitro; Injury; Kidney; Ligand Binding; Light; Location; Mediating; Mediator of activation protein; Molecular Biology Techniques; Morbidity - disease rate; Mus; Organ; Pathway interactions; Production; Proteins; Public Health; Role; Signal Pathway; Signal Transduction; Small Interfering RNA; Snails; Testing; Therapeutic; Transforming Growth Factor beta; Transforming Growth Factors; Tubular formation; base; biological adaptation to stress; cell type; genetic approach; improved; in vivo; inhibitor/antagonist; innovation; insight; migration; mortality; mouse model; novel; promoter; protective effect; public health relevance; receptor; renal epithelium; response; therapeutic target; tool; transcription factor

 DESCRIPTION (provided by applicant): Chronic kidney disease (CKD) is a growing public health problem that affects 10% of Americans, increases morbidity and mortality, and imposes a huge economic burden. Persistent renal tubular injury is an important component of tubulointerstitial fibrosis (TIF), the common feature of progressive CKD of any etiology. Growth factors such as transforming growth factor- (TGF) are important determinants of how tubula epithelia respond to injury. Although excessive TGF- signaling promotes TIF, blocking TGF-using genetic tools results in increased tubular damage after mouse models of CKD, suggesting that TGF-signaling has protective effects as well. TGF-mediates many differet cellular effects including G1 arrest of cell cycle progression and epithelial de-differentiation. Tis proposal tests the hypothesis that TGFsignaling in the proximal tubule promotes survival ater chronic renal injury by inducing cell cycle arrest and epithelial de- differentiation. The first ai investigates how TGF- alters cell cycle progression and how these changes affect epithelial survival using murine models of injury and pharmacologic inducers of G1 arrest. To test this, we will use genetically modified mice that lack the TGF receptor (TRII) specifically in the proximal tubule and induce chronic kidney injury by either angiotensin/ uninephrectomy or aristolochic acid. We anticipate that mice lacking TRII have impaired G1 arrest and reduced epithelial survival after injury and that this improves with administration of palbociclib, an FDA-approved inducer of G0/G1 cell cycle arrest. Proximal tubule cells with and without TRII in vitro will be used to understand the signaling pathways through which TGF- induces cell cycle arrest. The second aim explores mechanisms whereby TGFlters epithelial differentiation nd how these changes impact survival. The role of epithelial differentiation in chronic kidney injury will be defined using mice with epithelial-specific deletion of Snail, a key transcription factor downstream of TGF- Proximal tubule cells with and without TRII will be transfected with siRNA and constructs in vitro to test the hypothesis that Snail mediates TGF--dependent de-differentiation. The third aim defines how the Wnt/-catenin pathway, important in renal injury, interacts with TGF- to affect epithelial survival. Genetic models and cell culture techniques wil be used to test the hypothesis that TGF- increases canonical Wnt/catenin signaling to improve epithelial survival through increased de-differentiation and G0/G1 cell cycle arrest. This proposal uses innovative genetic approaches and a new strategy for analyzing injury in a quantitative and location-specific way. These studies will provide valuable insights into the roles of cell cycle and epithelial plasticity in the epithelial response to CKD, focusing on the proximal tubule which is the target of acute kidney injury and a mediator of CKD. However, information about cell cycle, epithelial plasticity and response to chronic injury has implications beyond the kidney as most organ dysfunction results from chronic epithelial injury.

 描述（由申请人提供）：慢性肾病 (CKD) 是一个日益严重的公共卫生问题，影响着 10% 的美国人，增加了发病率和死亡率，并带来了巨大的经济负担。持续性肾小管损伤是肾小管间质纤维化的重要组成部分。 TIF）是任何病因进行性 CKD 的共同特征，生长因子如转化生长因子- (TGF-) 是重要的决定因素。尽管 TGF-β 信号传导促进 TIF，但使用遗传工具阻断 TGF-β 会导致 CKD 小鼠模型后肾小管损伤增加，这表明 TGF-β 信号传导也具有过度的保护作用。 -介导许多不同的细胞效应，包括细胞周期进程的 G1 停滞和上皮去分化。Tis 提案测试了以下假设：近曲小管中的 TGF-β 信号通过诱导细胞周期停滞和上皮去分化来促进慢性损伤后的存活。第一个 ai 使用小鼠损伤模型研究了 TGF-β 如何改变细胞周期进程以及这些变化如何影响上皮存活。 G1 期停滞的药理学诱导剂 为了测试这一点，我们将使用缺乏 TGF 受体的转基因小鼠。 (TRII) 特别存在于近端肾小管中，并通过血管紧张素/单肾切除术或马兜铃酸诱导慢性肾损伤。我们预计缺乏 TRII 的小鼠会损害 G1 期停滞并减少损伤后的上皮存活率，并且通过给予哌柏西利可以改善这种情况。 ，一种 FDA 批准的 G0/G1 细胞周期停滞诱导剂将用于在体外了解有或没有 TRII 的近曲小管细胞。第二个目标是探索 TGF-β 改变上皮细胞分化的机制以及这些变化如何影响存活率。 -Snail 的特异性删除，Snail 是 TGF- 下游的关键转录因子。带有或不带有 TRII 的近端小管细胞将被转染siRNA 并在体外构建以测试 Snail 介导 TGF-β 依赖性去分化的假设。第三个目标定义了在肾损伤中重要的 Wnt/β-连环蛋白通路如何与 TGF-β 相互作用以影响上皮细胞存活。模型和细胞培养技术将用于检验以下假设：TGF-β 增加典型的 Wnt/β-catenin 信号传导，从而通过增加该提案使用创新的遗传方法和新策略以定量和特定位置的方式分析损伤。这些研究将为了解这些作用提供有价值的见解。 上皮对 CKD 反应中细胞周期和上皮可塑性的影响，重点关注近端 然而，关于细胞周期、上皮可塑性和对慢性损伤的反应的信息对肾脏以外的疾病也有影响，因为大多数器官功能障碍是由慢性上皮损伤引起的。