Role of Amphiregulin in kidney fibrosis

项目总结摘要 我们研究的总体目标是开发新的治疗和检测/监测策略来预防 慢性肾脏疾病(CKD)和纤维化的进展。缺血再灌注致急性肾损伤(AKI) 小鼠单侧输尿管损伤(IRI)或单侧输尿管梗阻(UUO)诱导持续的EGFR活化和肾脏纤维化 这可以通过近端小管细胞(PTCs)中EGFR的化学抑制或其基因缺失来防止。这个 具体的表皮生长因子受体配体(S)仍不清楚。我们发现A-去整合素和金属蛋白酶-17 (ADAM17)近端小管敲除对损伤诱导的纤维化的保护作用，确定促纤维化的来源 EGFR配体到PTCs。在损伤的小鼠肾脏中，EGFR配体前-两性调节素(Pro-AREG)非常 在人类中，AKI和CKD患者的尿中sAREG显著升高， 以及纤维化的慢性肾脏病肾活检。在体外，sAREG诱导人近端小管细胞(HPTCs) 持续的EGFR激活和促纤维化靶点。(Kefalogianni JCI Insight 2016)。这样做的目的是 应用是确定sAREG在AKI后早期和晚期损伤修复阶段中的作用，并牢固地联系 人类患者样本中的SAREG与肾脏纤维化和CKD进展有关。我们的中心假设是 两性调节蛋白(SAREG)是表皮生长因子受体(EGFR)的关键配体，负责诱导 以及在肾脏损伤中放大促纤维化的EGFR信号。我们基于初步数据，包括：(1)sAREG 根据sAREG注射和PTC-KO，是诱导小鼠肾损伤后纤维化的充分和必要的 对小鼠的研究(2)肾切除患者队列患者的血清样本中sAREG显著升高 CKD及其水平与肾功能参数呈负相关。这个项目的基本原理是 完成后将确定sAREG作为CKD/纤维化的新的治疗靶点和生物标记物，并确定 涉及的分子机制。我们计划用两个具体目标来测试我们的中心假设：AIM1：确定 AREG对于IRI损伤后早期肾脏恢复和/或肾脏纤维化的发展是否必要。 目的：在波士顿肾活检中，将sAREG与人类肾脏纤维化程度和CKD分期联系起来。 队列(BKBC，n=770)和慢性肾功能不全队列中的CKD进展(CRIC，n=3889)。这里 我们将把sAREG血/尿水平与肾活检和慢性肾脏病进展的肾纤维化联系起来，并进行比较。 与目前使用的肾脏生物标志物(肌酐、蛋白尿)的相关性。作为结果，我们预计AREG 近端小管敲除对损伤诱导的纤维化具有保护作用，sAREG水平与慢性肾脏病相关 结果和表现优于目前的生物标记物(肌酐、蛋白尿)。这一贡献是巨大的 因为它有望对CKD/纤维化的检测、预防和治疗产生影响。我们的研究是 在我们看来，这是一种创新，因为它将首次识别出一种直接 与纤维化过程机械连接，可用于治疗靶向和监测。

PROJECT SUMMARY ABSTRACT The overall goal of our research is to develop novel therapeutic and detection/monitoring strategies to prevent progression of chronic kidney disease (CKD) and fibrosis. Acute kidney injury (AKI) due to ischemia reperfusion injury (IRI) or unilateral ureteral obstruction (UUO) in mice induces sustained EGFR activation and kidney fibrosis which is prevented by EGFR chemical inhibition or its genetic deletion in proximal tubule cells (PTCs). The specific EGFR ligand(s) involved remain unknown. We showed that A-disintegrin-and-metalloprotease-17 (ADAM17) proximal tubule knockout protects against injury-induced fibrosis, identifying the source of pro-fibrotic EGFR ligands to PTCs. In the injured mouse kidney, the EGFR ligand pro-Amphiregulin (pro-AREG) was very strongly upregulated and in humans sAREG was very significantly elevated in the urine of AKI and CKD patients, as well as fibrotic CKD kidney biopsies. In vitro, in human proximal tubule cells (HPTCs), sAREG induced sustained EGFR activation and pro-fibrotic targets. (Kefalogianni JCI Insight 2016). The objective of this application is to determine the role of sAREG in early vs. late injury-repair stages after AKI and to firmly link sAREG in human patient samples to kidney fibrosis and to CKD progression. Our central hypothesis is that Amphiregulin (sAREG) is the key epidermal growth factor receptor (EGFR) ligand that is responsible for inducing and amplifying pro-fibrotic EGFR signals in kidney injury. We base this on preliminary data including: (1) sAREG is sufficient and necessary to induce fibrosis after kidney injury in mice, based on sAREG injection and PTC-KO studies in mice (2) sAREG is significantly elevated in serum samples of a nephrectomy cohort of patients with CKD and its levels correlate negatively with kidney function parameters. The rationale for this project is that completion will identify sAREG as a novel therapeutic target and biomarker in CKD/fibrosis, and identify molecular mechanisms involved. We plan to test our central hypothesis with two specific aims: AIM1: Determine whether AREG is necessary for early renal recovery and/or the development of kidney fibrosis after IRI injury. AIM2: To link sAREG to degree of kidney fibrosis and stage of CKD in humans in the Boston Kidney Biopsy Cohort (BKBC, n=770) and to CKD progression in the Chronic-Renal-Insufficiency-Cohort (CRIC, n=3889). Here we will correlate sAREG serum/urine levels to kidney fibrosis on biopsy and CKD progression, and compare this to correlation with currently used kidney biomarkers (Creatinine, proteinuria). As outcomes, we expect that AREG proximal tubule knockout protects against injury-induced fibrosis and that sAREG levels correlate with CKD outcomes and perform better than current biomarkers (creatinine, proteinuria). This contribution is significant because it is expected to have impact on CKD/fibrosis detection, prevention and treatment. Our research is innovative, in our opinion, because, it would for the first time identify a kidney fibrosis biomarker that is directly mechanistically connected to the fibrotic process and could be used for therapeutic targeting and monitoring.