Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin, Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Deutsches Rheuma-Forschungszentrum, an Institute of the Leibniz Foundation, Berlin, Germany.
Systems Biology of Gene-Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.
Kidney Int. 2022 Dec;102(6):1359-1370. doi: 10.1016/j.kint.2022.07.032. Epub 2022 Aug 29.
Acute kidney injury (AKI) is a major health issue, the outcome of which depends primarily on damage and reparative processes of tubular epithelial cells. Mechanisms underlying AKI remain incompletely understood, specific therapies are lacking and monitoring the course of AKI in clinical routine is confined to measuring urine output and plasma levels of filtration markers. Here we demonstrate feasibility and potential of a novel approach to assess the cellular and molecular dynamics of AKI by establishing a robust urine-to-single cell RNA sequencing (scRNAseq) pipeline for excreted kidney cells via flow cytometry sorting. We analyzed 42,608 single cell transcriptomes of 40 urine samples from 32 patients with AKI and compared our data with reference material from human AKI post-mortem biopsies and published mouse data. We demonstrate that tubular epithelial cells transcriptomes mirror kidney pathology and reflect distinct injury and repair processes, including oxidative stress, inflammation, and tissue rearrangement. We also describe an AKI-specific abundant urinary excretion of adaptive progenitor-like cells. Thus, single cell transcriptomics of kidney cells excreted in urine provides noninvasive, unprecedented insight into cellular processes underlying AKI, thereby opening novel opportunities for target identification, AKI sub-categorization, and monitoring of natural disease course and interventions.
急性肾损伤 (AKI) 是一个主要的健康问题，其结果主要取决于肾小管上皮细胞的损伤和修复过程。AKI 的发病机制仍不完全清楚，缺乏特定的治疗方法，临床常规监测 AKI 的进程仅限于测量尿液量和滤过标志物的血浆水平。在这里，我们通过建立一种稳健的通过流式细胞分选对尿液细胞进行单细胞 RNA 测序 (scRNAseq) 的方法，展示了通过评估 AKI 的细胞和分子动态来评估 AKI 的新方法的可行性和潜力。我们分析了 32 名 AKI 患者的 40 个尿液样本的 42,608 个单细胞转录组，并将我们的数据与来自人类 AKI 死后活检的参考材料和已发表的小鼠数据进行了比较。我们证明了肾小管上皮细胞的转录组反映了肾脏病理学，并反映了不同的损伤和修复过程，包括氧化应激、炎症和组织重排。我们还描述了 AKI 特异性的适应性祖细胞样细胞的大量尿液排泄。因此，尿液中排泄的肾脏细胞的单细胞转录组为 AKI 潜在的细胞过程提供了非侵入性的、前所未有的见解，从而为靶标鉴定、AKI 细分、以及自然疾病进程和干预措施的监测开辟了新的机会。
