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

基本信息

批准号：
10540412
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
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-01 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10540412
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 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 Modeling Molecular Mus Muscle satellite cell NTN1 gene Nephrons Organ Organogenesis Pattern Perfusion Phenotype Proliferating Proteins Regulation Renal Replacement Therapy Renal Tissue Reporting Role Signal Transduction Smooth Muscle Smooth Muscle Myocytes Specific qualifier value Stromal Cells Survival Rate System Testing Time Transgenic Mice Trees Vascular Smooth Muscle Vascular remodeling angiogenesis cell type in vivo kidney vascular structure mouse model mutant neogenin nephrogenesis nephron progenitor netrin receptor overexpression pharmacologic postnatal receptor renal artery renal hypoxia stem cells transcription factor

项目摘要

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.

概括大约 500,000 美国人患有终末期肾病。虽然器官功能可以辅以透析，10年生存率略高于10%。离体器官发生具有潜力通过提供用于肾脏替代治疗的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性肾脏、肾脏内的所有细胞类型及其功能性个体发育和耦合必须被理解。肾血管是对健康和体内平衡至关重要的组成部分之一肾脏的。构建肾脏复杂的动脉网络需要内皮细胞的同步作用 (EC) 和血管平滑肌细胞 (vSMC) 的序列尚不清楚。 vSMCs 出现在由 Foxd1+ 肾源性基质细胞 (NSC) 发育而来的肾脏。 Foxd1 或 Foxd1+ 细胞的消融会导致肾动脉中的类似缺陷表明 Foxd1+ NSC 编码的信号可能控制肾动脉生成。我们发现分泌性层粘连蛋白样蛋白 Netrin-1 (Ntn1) 在 Foxc1+ NSC 中表达胚胎肾。迄今为止，Ntn1 在肾脏发育过程中的作用尚未见报道。 Foxd1+ NSC（以下称为 Ntn1NSCKO）中 Ntn1 的基因消融可阻止灌注的形成发育期间的肾动脉树。此外，我们发现 Ntn1NSCKO 显示异常的 vSMC 相关皮质血管系统和肾脏缺氧增加。随着开发的进行，Ntn1NSCKO 也表现出减少输尿管芽 (UB) 分支和出生后 Ntn1NSCKO 小鼠表现出肾发生延迟，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，但其机制该规定未知。在本提案中，我们解决了这个问题并询问肾脏需要哪种受体形成：基质-neogenin1、NPC-Unc5b 或内皮-Unc5b？我们假设 NSC 衍生的 Ntn1 细胞通过其自主指导 vSMC 谱系规范受体neogenin1 (Neo1) 和转录因子Klf4，指导肾动脉树组装，哪个肾单位的发育间接取决于。我们将通过实现以下目标来检验这一假设： 1) 我们将通过询问如何在肾动脉组装过程中测试 NSC 衍生的 Ntn1 信号传导的细胞自主性基质在 Ntn1 缺失时做出反应，异位 SMC 来源于突变体，而 Ntn1 动脉发育需要受体（因此需要哪些细胞类型）（概括了 Ntn1 表型）消融时）。 2) 我们将检查异常肾发生是否直接由 NPC 中 Ntn1 缺失引起，或间接由于肾动脉生成失败。我们将表征 Ntn1 突变体中失败的肾发生肾脏；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 EC）；我们将测试 Ntn1 的晚期删除是否会重现 Ntn1 突变表型，因为它绕过了失败的动脉生成和相关缺氧；最后我们将直接测试缺氧对NPC的作用。 3）我们将检查Klf4是否是基质分化和肾动脉生成所必需的，以及它是否向 Ntn1 下游发出信号。