Importance of cell-matrix interactions in kidney repair after acute kidney injury

细胞-基质相互作用在急性肾损伤后肾脏修复中的重要性

• 批准号: 10585440
• 负责人: Dong Zhou
• 金额: $ 50.19万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10585440
• 关键词: 3-Dimensional; Acute Renal Failure with Renal Papillary Necrosis; Affect; Attention; Binding; Biological; Cell Death; Cell Proliferation; Cells; Cessation of life; Chronic Kidney Failure; Complex; Creatinine; Data; Deterioration; Development; Disease; Environment; Extracellular Matrix; Extracellular Matrix Proteins; Fibroblasts; Glycoproteins; Growth Factor; Hospitalization; In Vitro; Incubated; Inflammatory; Injury to Kidney; Investigation; Ischemia; Kidney; Knockout Mice; Macrophage; Maintenance; Mediating; Modeling; Output; Pathogenesis; Peptides; Process; Proteins; Proteomics; Regimen; Renal function; Renal tubule structure; Repression; Research; Risk; Role; SHH gene; Serum; Shapes; Signal Transduction; Source; System; Techniques; Testing; Treatment Efficacy; Tubular formation; Urine; cell type; conditional knockout; design; in vivo; injured; injury and repair; insight; interstitial; kidney cell; kidney repair; knock-down; long-term sequelae; new therapeutic target; novel; novel therapeutic intervention; novel therapeutics; overexpression; prevent; recruit; renal ischemia; repaired; scaffold; tumorigenesis

PROJECT SUMMARY/ABSTRACT Acute kidney injury (AKI) is characterized by abrupt deterioration in kidney function, manifested by an increase in serum creatinine level, with or without a reduction in the amount of urine output. Tragically, between 2009- 2019, hospitalizations in the US complicated by AKI increased by 42%. The long-term objectives of this application are to better understand the kidney local microenvironment and its impact on AKI with an eye towards development of new treatment strategies. The AKI research field believes that renal tubules are the epicenter of damage, yet little attention has been paid to changes in the renal local microenvironment and associated repair processes, which are certain to impact AKI. The concept of a ‘microenvironment’ has shaped the understanding of the pathogenesis of various diseases. However, the AKI microenvironment is poorly characterized. The kidney local microenvironment in AKI - consisting of injured tubular cells, activated fibroblasts, inflammatory cells (e.g., macrophages), other cellular components, extracellular matrix (ECM), and a variety of secreted factors - is complex, heterotypic, and dynamic. After AKI, in general, renal tubules undergo a repair process of dedifferentiation. During this process, ECM is the major organizing component for microenvironment construction and tubule repair, serving as a scaffold for remodeling. The major cellular source of ECM synthesis in the kidney is interstitial fibroblasts. Several subpopulations of fibroblasts are activated exceptionally early after AKI (1h), far earlier than tubular cell proliferation (3d). This suggests that fibroblast-derived proteins may act early in AKI. To explore this idea in depth, matrix proteins were compared between AKI and control kidneys using ischemic kidney models and proteomics. This identified extracellular matrix protein 1 (ECM1; a secreted glycoprotein) as the earliest and highest activated matrix protein after ischemic AKI. ECM1 was induced rapidly (4-8h) after AKI and localized predominantly to fibroblast-rich foci in the kidney interstitium. It was also found that after AKI, Sonic Hedgehog (Shh) growth factor secreted by renal tubules specifically targets fibroblasts to mediate cell-matrix interactions. Further study revealed that ECM1 binds to Shh in vitro, knockdown of ECM1 aggravates AKI in vivo, and ECM1 peptide prevents tubular cell death in vitro. Based on these observations and the role of macrophages in microenvironment formation, it was hypothesized that after AKI, ECM1 directly recruits Shh, which activates fibroblasts and macrophages to form a favorable microenvironment to promote kidney remodeling. This hypothesis will be tested by determining the mechanistic role of ECM1 in kidney microenvironment formation ex vivo (Aim 1); determining the roles of injured tubules, activated fibroblasts, and macrophages in constructing the kidney microenvironment after AKI (Aim 2); and determining the role of the ECM1-organized cell-matrix interactions in promoting AKI repair in vivo (Aim 3). Our investigations have broad implications for elucidating mechanisms for kidney repair and designing novel therapeutic regimens to prevent or mitigate AKI.

项目总结/摘要 急性肾损伤（阿基）的特征是肾功能突然恶化，表现为肾功能损害程度增加。 血清肌酐水平，伴或不伴尿量减少。不幸的是，在2009年- 2019年，美国因阿基并发症住院的人数增加了42%。这一长期目标 应用是为了更好地了解肾脏局部微环境及其对阿基的影响， 制定新的治疗策略。阿基研究领域认为，肾小管是 损伤，但很少注意到肾脏局部微环境的变化和相关的修复 这些过程肯定会影响阿基。“微环境”的概念塑造了人们对 各种疾病的发病机理。然而，阿基微环境的特征很差。肾脏 阿基中的局部微环境-由受损的肾小管细胞、活化的成纤维细胞、炎性细胞（例如， 巨噬细胞），其他细胞成分，细胞外基质（ECM）和各种分泌因子-是 复杂、异型和动态。在阿基之后，一般来说，肾小管经历一个修复过程， 去分化在这一过程中，ECM是构建微环境的主要组织成分 和小管修复，作为重塑的支架。肾脏中ECM合成的主要细胞来源 是间质成纤维细胞成纤维细胞的几个亚群在阿基后异常早期（1小时）被激活， 早于肾小管细胞增殖（3d）。这表明成纤维细胞衍生的蛋白质可能在阿基的早期起作用。到 为了深入探讨这一想法，使用缺血性肾损伤模型比较了阿基和对照肾之间的基质蛋白。 肾脏模型和蛋白质组学。细胞外基质蛋白1（ECM 1;一种分泌的糖蛋白）被鉴定为 缺血阿基后最早和最高的活化基质蛋白。阿基后4-8h，ECM 1迅速诱导 并且主要局限于肾间质中富含成纤维细胞的病灶。还发现，在阿基之后，Sonic 由肾小管分泌的Hedgehog（Shh）生长因子特异性靶向成纤维细胞以介导细胞基质 交互.进一步的研究表明，ECM 1在体外与Shh结合，ECM 1的敲低在体内抑制阿基， 和ECM 1肽在体外防止肾小管细胞死亡。根据这些观察和巨噬细胞的作用， 在微环境形成中，假设阿基后，ECM 1直接招募Shh， 成纤维细胞和巨噬细胞，以形成有利的微环境，促进肾脏重塑。这 将通过确定ECM 1在肾脏微环境形成中的机制作用来检验这一假设， 体内（目的1）;确定损伤的肾小管，活化的成纤维细胞和巨噬细胞在构建 阿基后的肾脏微环境（目的2）;并确定ECM 1组织的细胞基质的作用 在促进体内阿基修复中的相互作用（Aim 3）。我们的调查对阐明 肾修复机制和设计新的治疗方案，以预防或减轻阿基。