Renal vascular remodeling and arteriogenesis: cues from smooth muscle progenitor cells

肾血管重塑和动脉生成：来自平滑肌祖细胞的线索

• 批准号: 10320039
• 负责人: Ondine B Cleaver
• 金额: $ 35.25万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10320039
• 关键词: Ablation; Acute Renal Failure with Renal Papillary Necrosis; Address; Adult; Affect; American; Blood Vessels; Blood flow; Bypass; Cell Differentiation process; Cell Lineage; Cell model; Cells; Coupling; Cues; Data; Defect; Development; Dialysis procedure; Embryo; End stage renal failure; Endothelial Cells; Endothelium; Event; Exhibits; FOXC1 gene; Genetic; Goals; Growth; Health; Homeostasis; Hypertension; Hypoxia; Impairment; In Vitro; Invaded; Kidney; Kidney Failure; Laboratories; Laminin; Metanephric Diverticulum; Molecular; Mus; Muscle satellite cell; NTN1 gene; Nephrons; Organ; Organogenesis; Pattern; Pharmacology; Phenotype; Proteins; Regulation; Renal Replacement Therapy; Renal Tissue; Reporting; Role; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Stromal Cells; Survival Rate; System; Testing; Time; Transgenic Mice; Trees; Vascular Smooth Muscle; Vascular remodeling; angiogenesis; cell type; in vitro testing; in vivo; kidney vascular structure; mouse model; mutant; neogenin; nephrogenesis; nephron progenitor; overexpression; postnatal; receptor; renal artery; renal hypoxia; stem cells; transcription factor

SUMMARY Approximately 500,000 Americans have end-stage renal disease. Although organ function can be supplemented using dialysis, the 10-year survival rate is just over 10%. Ex vivo organogenesis has the potential to meet this demand by providing functional tissue for renal replacement therapy. However to effectively generate functional kidneys in the laboratory, all cell types within the kidney and their functional ontogeny and coupling must be understood. Renal blood vessels are one such component that is critical to the health and homeostasis of the kidney. Building the kidney's intricate arterial network requires synchronized actions of endothelial cells (ECs) and vascular smooth muscle cells (vSMCs) in a sequence that is poorly understood. vSMCs arise in the developing kidney from Foxd1+ nephrogenic stromal cells (NSCs). Ablation of Foxd1 or Foxd1+ cells cause similar defects in renal arteries suggesting Foxd1+ NSC encoded signals may govern renal arteriogenesis. We have found that the secreted laminin-like protein Netrin-1 (Ntn1) is expressed by Foxc1+ NSCs in the embryonic kidney. To date, the role of Ntn1 during kidney development has not been reported. Genetic ablation of Ntn1 from Foxd1+ NSCs (hereafter denoted as Ntn1NSCKO) blocks formation of a perfused renal arterial tree during development. In addition, we find Ntn1NSCKO display an aberrant vSMCs-associated cortical vasculature and increased kidney hypoxia. As development proceeds, Ntn1NSCKO also exhibit reduced ureteric bud (UB) branching, and postnatal Ntn1NSCKO mice display delayed nephrogenesis with ~30% fewer glomeruli. Our preliminary data identifies a critical role for Ntn1 in kidney development, but the mechanism(s) of this regulation is unknown. In this proposal, we address this and ask which receptor is needed for kidney formation: stromal-neogenin1, NPC-Unc5b or endothelial-Unc5b? We hypothesize that NSC-derived Ntn1 cell-autonomously directs vSMC lineage specification via its receptor neogenin1 (Neo1) and the transcription factor Klf4, to instruct renal arterial tree assembly, upon which nephron development indirectly depends. We will test this hypothesis by carrying out following aims: 1) We will test the cell autonomy of NSC-derived Ntn1 signaling during renal arterial assembly, by asking how the stroma responds upon absence of Ntn1, where ectopic SMCs come from in the mutants, and which Ntn1 receptors (hence which cell types) are required for arterial development (which recapitulate the Ntn1 phenotype when ablated). 2) We will examine if aberrant nephrogenesis is caused directly via Ntn1 loss in NPCs, or indirectly due to failure of renal arteriogenesis. We will characterize failed nephrogenesis in the Ntn1 mutant kidneys; we will use in vitro systems to see what cell types respond to Ntn1 (NPCs versus ECs); we will test whether late deletion of Ntn1 recapitulates the Ntn1 mutant phenotype, as it bypasses failed arteriogenesis and associated hypoxia; and lastly we will test the role of hypoxia on NPCs directly. 3) We will examine whether Klf4 is required for stromal differentiation and renal arteriogenesis, and whether it signals downstream of Ntn1.

摘要 大约有50万美国人患有终末期肾病。尽管器官功能可以 再加上透析，10年存活率仅略高于10%。体外器官发生具有潜在的 通过为肾脏替代疗法提供功能组织来满足这一需求。然而，要有效地产生 实验室中的功能肾脏，肾脏内的所有细胞类型及其功能个体发育和偶联 必须被理解。肾血管是一种对健康和动态平衡至关重要的成分。 肾脏的组织结构。构建肾脏错综复杂的动脉网络需要内皮细胞的同步行动 (ECS)和血管平滑肌细胞(VSMCs)在一种鲜为人知的序列中。VSMC产生于 从Foxd1+肾基质细胞(NSCs)发育肾脏。Foxd1或Foxd1+细胞的消融导致 肾动脉中类似的缺陷表明Foxd1+NSC编码的信号可能控制着肾动脉的形成。 我们发现分泌的层粘连蛋白样蛋白Netrin-1(Ntn1)是由Foxc1+NSCs在 胚胎肾脏。到目前为止，Ntn1在肾脏发育中的作用还没有报道。 从Foxd1+NSCs(以下称为Ntn1NSCKO)中基因消融Ntn1阻止了灌流的形成 发育中的肾动脉树。此外，我们发现Ntn1NSCKO表现出与vSMC相关的异常 皮质血管形成和肾脏缺氧增加。随着开发的进行，Ntn1NSCKO也表现出减少 输尿管芽(UB)分支，以及出生后Ntn1NSCKO小鼠表现出肾发育延迟，减少约30% 肾小球。我们的初步数据确定了Ntn1在肾脏发育中的关键作用，但其机制(S) 这一规定是未知的。在这项提案中，我们解决了这个问题，并询问肾脏需要哪种受体 形成：基质-新生蛋白1、NPC-Unc5b或内皮-Unc5b？ 我们假设NSC来源的Ntn1细胞自主地通过其 受体新生素1(Neo1)和转录因子KLF4，以指示肾动脉树组装，在 肾单位的发育间接依赖于。我们将通过实现以下目标来验证这一假设： 1)我们将通过询问以下问题来测试NSC衍生的Ntn1信号在肾动脉组装过程中的细胞自主性 间质在缺乏Ntn1时做出反应，Ntn1来自于突变体中的异位SMC 受体(因此哪些细胞类型)是动脉发育所必需的(它概括了Ntn1的表型 当被烧蚀时)。2)我们将检查异常肾生成是否直接通过Ntn1缺失在NPC中引起，或者 间接由于肾动脉生成失败所致。我们将在Ntn1突变体中描述肾发生失败的特征 肾脏；我们将使用体外系统来观察哪些细胞类型对Ntn1有反应(NPC与ECs)；我们将测试 Ntn1的晚期缺失是否重现了Ntn1突变的表型，因为它绕过了失败的动脉生成和 最后，我们将直接测试低氧对鼻咽癌细胞的作用。3)我们将检查KLF4是否 是基质分化和肾动脉形成所必需的，以及它是否在Ntn1下游发出信号。