The formation of kidney local microenvironment after acute kidney injury.

项目摘要/摘要 急性肾损伤(AKI)的特征是肾功能突然恶化，表现为肾功能增加 在有或不有尿量减少的情况下，血清肌酐水平。在美国，有接近 2000年，AKI住院人数增加到100万人，到2014年，这个数字翻了两番。发病率、死亡率和 AKI的成本比之前承认的要高得多。不管AKI的最初原因是什么，肾小管 被认为是破坏的震中。对肾脏局部的变化关注较少。 AKI中的微环境，尽管“微环境”的概念已经塑造了我们的理解 各种疾病的发病机制。急性肾损伤时肾脏微环境由不同的细胞组成 成分，如受损的肾小管细胞、活化的成纤维细胞、细胞外基质(ECM)和各种 隐藏的因素。一般来说，AKI后，肾小管经历了一个去分化的修复过程。在此期间 过程中，细胞外基质是组织促进小管形成的良好微环境不可缺少的组成部分 重新繁衍。为了进一步了解细胞外基质在肾脏微环境形成中的作用，我们 建立了从第0天到第10天10个不同时间点的缺血性肾损伤模型。 我们发现细胞外基质蛋白1(ECM1)是AKI后最早被激活的基质蛋白。 然后我们在实验上证实，早在AKI后4-8小时，ECM1就被迅速诱导，并且它 主要定位于富含成纤维细胞的病灶。在肾脏中，成纤维细胞是主要的细胞来源。 细胞外基质的合成。我的K01奖项产生的数据显示，在AKI中，成纤维细胞的激活是一种 优越的早期事件，它发生的时间远远早于肾小管细胞的增殖。与此同时，一部由小管派生的小说 生长因子Sonic Hedgehog(Shh)由肾小管分泌，专门针对成纤维细胞。通过 免疫沉淀，我们发现ECM1在体外可以与Shh配体结合。基于这些发现，我们 假设在AKI后，ECM1直接招募Shh形成有利的微环境 促进肾脏重塑。我们将在两个具体目标上检验这一假说：1)确定 ECM1在体外微环境形成中的作用。2)确定ECM1组织的角色 促进AKI体内修复的微环境。此应用程序生成的数据将具有广泛的 对了解肾脏修复的发病机制和设计新的治疗方案的意义 接受AKI治疗。

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. In the US, there was close to one million AKI hospitalizations in 2000, and this number quadrupled by 2014. The morbidity, mortality, and costs of AKI are far greater than formerly acknowledged. Regardless of the initial causes of AKI, renal tubules are considered to be the epicenter of damage. Little attention is paid to the changes of the renal local microenvironment in AKI, although the concept of a ‘microenvironment’ has already shaped our understanding of the pathogenesis of various diseases. The kidney microenvironment in AKI is comprised of different cellular components such as injured tubular cells, activated fibroblasts, extracellular matrix (ECM), and a variety of secreted factors. In general, after AKI, renal tubules undergo a repair process of dedifferentiation. During this process, ECM is an indispensable component in organizing a favorable microenvironment to promote tubule repopulation. To further understand the role of ECM in the formation of the kidney microenvironment, we constructed an ischemic kidney injury model at 10 different time points, from day 0 to 10. By using proteomics, we found that extracellular matrix protein 1 (ECM1) was the earliest activated matrix protein after ischemic AKI. We then experimentally confirmed that ECM1 was induced rapidly, as early as 4-8h after AKI, and it predominantly localizes at the foci rich in fibroblasts. In the kidney, the fibroblast is the major cellular resource of ECM synthesis. The data generated by my K01 award revealed that, in AKI, fibroblast activation is a superior early event, and it occurs far earlier than tubular cell proliferation. Meanwhile, a tubule-derived novel growth factor, Sonic Hedgehog (Shh) was secreted by renal tubules and specifically targets fibroblasts. By immunoprecipitation, we found that ECM1 can bind to the Shh ligand in vitro. Based on these findings, we hypothesized that after AKI, ECM1 directly recruits Shh to form a favorable microenvironment to promote kidney remodeling.We will test this hypothesis in two specific aims: 1) Determine the mechanistic role of ECM1 in microenvironment formation ex vivo. 2) Determine the role of the ECM1-organized microenvironment in promoting AKI repair in vivo. The data generated from this application will have wide implications in comprehending the pathogenesis of kidney repair and in designing novel therapeutic regimens for AKI treatment.