Department of Nephrology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China.
Key Laboratory of Biological Nanotechnology of National Health Commission, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China.
Chin Med J (Engl). 2023 May 20;136(10):1177-1187. doi: 10.1097/CM9.0000000000002679. Epub 2023 Apr 20.
Ischemic acute kidney injury (AKI) is a common syndrome associated with considerable mortality and healthcare costs. Up to now, the underlying pathogenesis of ischemic AKI remains incompletely understood, and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking. Here, this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing (scRNA-seq) analysis in kidneys.
In this study, scRNA-seq technology was applied to kidneys from two ischemic AKI patients, and three human public scRNA-seq datasets were collected as controls. Differentially expressed genes (DEGs) and cell clusters of kidneys were determined. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, as well as the ligand-receptor interaction between cells, were performed. We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion (I/R) injury induced AKI mice through immunohistochemistry staining.
15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control. The injured proximal tubules (PT) displayed a proapoptotic and proinflammatory phenotype. PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47 , RASSF4 , EBAG9 , IER3 , SASH1 , SEPTIN7 , and NUB1 , which have not been reported in ischemic AKI previously. Several hub genes were validated in kidneys from human AKI and renal I/R injury mice, respectively. Furthermore, PT highly expressed DEGs enriched in endoplasmic reticulum stress, autophagy, and retinoic acid-inducible gene I (RIG-I) signaling. DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain (NOD)-like receptor signaling, estrogen signaling, interleukin (IL)-12 signaling, and IL-17 signaling. Overexpressed genes in kidney-resident immune cells including macrophages, natural killer T (NKT) cells, monocytes, and dendritic cells were associated with leukocyte activation, chemotaxis, cell adhesion, and complement activation. In addition, the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI.
Together, this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients, altered signaling pathways, and potential cell-cell crosstalk in the development of AKI. These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.
缺血性急性肾损伤（AKI）是一种常见的综合征，与相当高的死亡率和医疗保健费用有关。迄今为止，缺血性 AKI 的发病机制仍不完全清楚，也缺乏针对缺血性 AKI 的早期诊断和治疗的具体策略。在这里，本研究旨在通过肾脏的单细胞 RNA 测序（scRNA-seq）分析来定义 AKI 患者的转录组图谱。
在这项研究中，应用 scRNA-seq 技术对两名缺血性 AKI 患者的肾脏进行分析，并收集了三个公开的人类 scRNA-seq 数据集作为对照。确定肾脏中的差异表达基因（DEGs）和细胞簇。进行基因本体论（GO）和京都基因与基因组百科全书（KEGG）通路富集分析，以及细胞之间的配体-受体相互作用。我们还通过免疫组织化学染色验证了几个人类缺血性 AKI 和缺血/再灌注（I/R）损伤诱导的 AKI 小鼠肾脏中的 DEGs 表达。
在缺血性 AKI 和对照受试者的肾脏中确定了 15 个不同的细胞簇。受损的近端肾小管（PT）表现出促凋亡和促炎表型。缺血性 AKI 的 PT 细胞上调了以前在缺血性 AKI 中未报道过的新型促凋亡基因，包括 USP47、RASSF4、EBAG9、IER3、SASH1、SEPTIN7 和 NUB1。在人 AKI 和肾 I/R 损伤小鼠的肾脏中分别验证了几个关键基因。此外，PT 中高度表达的 DEGs 富集在内质网应激、自噬和视黄酸诱导基因 I（RIG-I）信号通路中。在其他管状细胞中过度表达的 DEGs 主要富集在核苷酸结合和寡聚结构域（NOD）样受体信号、雌激素信号、白细胞介素（IL）-12 信号和 IL-17 信号通路中。在肾脏固有免疫细胞（包括巨噬细胞、自然杀伤 T（NKT）细胞、单核细胞和树突状细胞）中过度表达的基因与白细胞激活、趋化性、细胞粘附和补体激活有关。此外，配体-受体相互作用分析显示，在缺血性 AKI 过程中，巨噬细胞和单核细胞与其他细胞之间存在明显的通讯。
综上所述，本研究揭示了缺血性 AKI 患者肾脏中独特的细胞特异性转录组图谱、改变的信号通路以及 AKI 发展过程中的潜在细胞间串扰。这些数据为缺血性 AKI 的发病机制和潜在治疗策略提供了新的见解。
