Remote injury responses after AKI

项目总结摘要 我们研究的总体目标是开发治疗急性肾脏继发性并发症的新策略。 伤害(AKI)。摘要远端急性肺损伤(ALI)是急性肾损伤(AKI)常见且往往致命的并发症。 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，如肿瘤坏死因子(TNF)和T细胞已被涉及。哪些特定的肾脏细胞类型 释放以及哪些肺细胞类型或免疫细胞是这些介体的靶点尚不清楚。巨噬细胞 AKI-ALI在小鼠和人类的肺部蓄积已有报道，但这种蓄积是否通过募集发生 骨髓来源的循环CCR2单核细胞或组织驻留巨噬细胞的增殖 未知。巨噬细胞反应及其异质性是组织反应的关键决定因素 受伤。AKI诱导的整体肺远程免疫反应与肺巨噬细胞的来源和异质性 在AKI-ALI中都不为人知。本应用的目的是确定近端小管细胞(PTC)的作用。 AKI-ALI肺间质巨噬细胞来源的肿瘤坏死因子和肿瘤坏死因子受体1的来源及异质性 AKI后肾/肺巨噬细胞的变化，并比较肾和肺的局部和远程损伤反应 在AKI之后。我们的中心假设是：(1)PTC来源的肿瘤坏死因子是AKI-ALI的介质；(2)局部和远程 免疫反应有共同的特征，但也有重要的区别。我们的初步工作表明 PTC来源的肿瘤坏死因子介导炎症和依赖CCR2的间质巨噬细胞向肺的募集。 并以肺间质巨噬细胞为靶细胞。我们发现了局部和远程损伤反应的相似性，但也 显著差异，例如肺对急性心肌梗死和急性心肌梗死的反应。这样做的理由是 该项目的完成将(1)确定PTC来源的肿瘤坏死因子为AKI-ALI的介质，并将肺间质 巨噬细胞作为其在肺中的靶细胞，以及(2)确定局部的共同特征和显著差异 以及可用于靶向治疗的远程免疫反应。我们计划测试我们的中央 有两个特定目的的假说：目标1：确定PTC来源的肿瘤坏死因子和TNFR1间质的作用 AKI-ALI巨噬细胞敲除(使用细胞类型特异的KO小鼠)目的2：确定间质来源 巨噬细胞在AKI-ALI中的异质性，并比较局部肾脏免疫细胞对远程 AKI-ALI患者的肺免疫细胞反应(使用命运图和scRNAseq)。作为结果，我们预计肿瘤坏死因子- PTC-KO可预防AKI-ALI，比较局部和远程损伤反应确定了重要的 不同之处。这一贡献意义重大，因为预计它将在开发中产生翻译影响 高死亡率的继发性AKI并发症的治疗，如AKI-ALI。我们的研究是创新的， 我们认为，因为它将首次确定源细胞(PTC)和目标细胞(间隙 巨噬细胞在肾脏中表达AKI-ALI介质，并首次使用单细胞RNAseq来定义局部 和远程免疫反应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.