Remote injury responses after AKI

项目摘要 我们研究的总体目标是开发新的策略来治疗急性肾脏病的继发性并发症。 损伤（AKI）。陈旧性急性肺损伤（ALI）是急性肾损伤（AKI）的常见并发症，往往是致命的 缺乏治疗方法AKI-ALI的分子机制尚不完全清楚，但循环炎症 细胞因子，例如肿瘤坏死因子（TNF）和T细胞已经被牵涉。哪些特定的肾细胞类型 这些介质的释放以及哪些肺细胞类型或免疫细胞被这些介质靶向是未知的。巨噬 在小鼠和人的AKI-ALI中，已经报道了在肺中的蓄积，但是这是否通过募集而发生， 骨髓来源的循环CCR2+单核细胞的增殖或组织驻留巨噬细胞的增殖， 未知巨噬细胞反应以及它们的异质性是组织反应的关键决定因素， 损伤肺对AKI的整体远程免疫应答以及肺巨噬细胞的来源和异质性 在AKI-ALI是未知的。本申请的目的是确定近端小管细胞（PTC）的作用。 在AKI-ALI中肺间质巨噬细胞中的TNF和TNFR 1，以确定起源和异质性 AKI后肾/肺巨噬细胞的损伤，并比较肾和肺中的局部和远程损伤反应 AKI之后我们的中心假设是（1）PTC衍生的TNF是AKI-ALI介导剂，（2）局部和远端 免疫反应具有共同的特征，但也有重要的区别。我们的初步工作表明， PTC衍生的TNF介导炎症和CCR2+依赖性间质巨噬细胞向肺的募集， 并靶向肺间质巨噬细胞。我们发现了局部和远程损伤反应的相似性， 显著差异，例如肺对AKI的反应与对急性心肌梗死的反应。这样做的理由 该项目的完成将（1）确定PTC衍生的TNF作为AKI-ALI介质， 巨噬细胞作为其在肺中的靶细胞，和（2）识别局部的共同特征和显著差异， 和远程免疫反应，可以用于靶向治疗。我们计划测试我们的中央 有两个特定目标的假设：目的1：确定PTC衍生的TNF和TNFR 1间质的作用 AKI-ALI中的巨噬细胞敲除（使用细胞类型特异性KO小鼠） 巨噬细胞及其异质性，并比较局部肾免疫细胞反应与远程 AKI-ALI中的肺免疫细胞应答（使用fat-mapping和scRNAseq）。作为结果，我们预计TNF-α- PTC-KO可预防AKI-ALI，局部和远端损伤反应的比较确定了重要的 差异这一贡献是重要的，因为它预计将在发展中产生转化影响。 治疗具有高死亡率的继发性AKI并发症，如AKI-ALI。我们的研究是创新的， 在我们看来，因为它将首次识别源细胞（PTC）和靶细胞（间质细胞）， 巨噬细胞_的AKI-ALI介质在肾脏中，并首次使用单细胞RNAseq来定义局部 和远程免疫应答AKI-ALI。

PROJECT SUMMARY ABSTRACT The overall goal of our research is to develop novel strategies to treat secondary complications of acute kidney injury (AKI). Remote acute lung injury (ALI) is a frequent and often lethal complication of acute kidney injury (AKI) that lacks therapies. Molecular mechanisms of AKI-ALI are incompletely understood, but circulating inflammatory cytokines, e.g. tumor-necrosis-factor (TNF) and T cells have been implicated. Which specific kidney cell types release and which lung cell types or immune cells are targeted by these mediators is unknown. Macrophage accumulation in the lung has been reported in AKI-ALI in mice and human, but whether this occurs by recruitment of bone marrow-derived circulating CCR2+monocytes or proliferation of tissue resident macrophages is unknown. Macrophage responses as well as their heterogeneity are critical determinants of tissue responses to injury. The overall lung remote immune response to AKI and the origin and heterogeneity of lung macrophages in AKI-ALI are unknown. The objective of this application is to determine the role of proximal tubule cell (PTC)- derived TNF and of TNFR1 in lung interstitial macrophages in AKI-ALI, to determine the origin and heterogeneity of kidney/lung macrophages after AKI, and to compare local and remote injury responses in kidney and lung after AKI. Our central hypothesis is (1) PTC-derived TNF is an AKI-ALI mediators and (2) local and remote immune responses share common features but have important differences. Our preliminary work suggests that PTC-derived TNF mediates inflammation and CCR2+-dependent interstitial macrophage recruitment to the lung, and targets lung interstitial macrophages. We detect similarities in local and remote injury responses, but also significant differences, e.g in response of the lung to AKI vs. to acute myocardial infarction. The rationale for this project is that completion will (1) identify PTC-derived TNF as an AKI-ALI mediators, and lung interstitial macrophages as its target cell in the lung, and (2) identify common features and significant differences in local and remote immune responses that could be exploited for targeted therapies. We plan to test our central hypothesis with two specific aims: AIM 1: Determine the role of PTC-derived TNF and of TNFR1 interstitial macrophage knockout in AKI-ALI (using cell type-specific KO mice) AIM 2: Determine the origin of interstitial macrophages in AKI-ALI and their heterogeneity, and compare local kidney immune cell responses to remote lung immune cell responses in AKI-ALI (using fate-mapping and scRNAseq). As outcomes, we expect that TNF- PTC-KO protects against AKI-ALI, and that comparison of local and remote injury responses identifies important differences. This contribution is significant because it is expected to have translational impact in the development of treatments for secondary AKI complications with high mortality, such as AKI-ALI. Our research is innovative, in our opinion, because, it would for the first time identify the source (PTC) and target cells (interstitial macrophages_ of AKI-ALI mediators in the kidney, and for the first time use single cell RNAseq to define local and remote immune responses AKI-ALI.