Single Cell Dissection of Epithelial-Immune Cellular Interplay in Acute Kidney Injury Microenvironment

Min Zhang; Lingling Wu; Yiyao Deng; Fei Peng; Tiantian Wang; Yinghua Zhao; Pu Chen; Jiaona Liu; Guangyan Cai; Liqiang Wang; Jie Wu; Xiangmei Chen

doi:10.3389/fimmu.2022.857025

Single Cell Dissection of Epithelial-Immune Cellular Interplay in Acute Kidney Injury Microenvironment

Front Immunol. 2022 May 4:13:857025. doi: 10.3389/fimmu.2022.857025. eCollection 2022.

Authors

Min Zhang¹, Lingling Wu¹, Yiyao Deng², Fei Peng¹, Tiantian Wang¹, Yinghua Zhao¹, Pu Chen¹, Jiaona Liu¹, Guangyan Cai¹, Liqiang Wang³, Jie Wu¹, Xiangmei Chen¹

Affiliations

¹ Department of Nephrology, First Medical Center of Chinese People's Liberation Army (PLA) of China General Hospital, Nephrology Institute of the Chinese People's Liberation Army, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing Key Laboratory of Kidney Disease Research, Beijing, China.
² Department of Nephrology, Guizhou Provincial People's Hospital, Guiyang, China.
³ Department of Ophthalmology, Ophthalmology & Visual Science Key Lab of People's Liberation Army (PLA) of China, General Hospital of Chinese People's Liberation Army (PLA) of China, Beijing, China.

Abstract

Background: Understanding the acute kidney injury (AKI) microenvironment changes and the complex cellular interaction is essential to elucidate the mechanisms and develop new targeted therapies for AKI.

Methods: We employed unbiased single-cell RNA sequencing to systematically resolve the cellular atlas of kidney tissue samples from mice at 1, 2 and 3 days after ischemia-reperfusion AKI and healthy control. The single-cell transcriptome findings were validated using multiplex immunostaining, western blotting, and functional experiments.

Results: We constructed a systematic single-cell transcriptome atlas covering different AKI timepoints with immune cell infiltration increasing with AKI progression. Three new proximal tubule cells (PTCs) subtypes (PTC-S1-new/PTC-S2-new/PTC-S3-new) were identified, with upregulation of injury and repair-regulated signatures such as Sox9, Vcam1, Egr1, and Klf6 while with downregulation of metabolism. PTC-S1-new exhibited pro-inflammatory and pro-fibrotic signature compared to normal PTC, and trajectory analysis revealed that proliferating PTCs were the precursor cell of PTC-S1-new, and part of PTC-S1-new cells may turn into PTC-injured and then become fibrotic. Cellular interaction analysis revealed that PTC-S1-new and PTC-injured interacted closely with infiltrating immune cells through CXCL and TNF signaling pathways. Immunostaining validated that injured PTCs expressed a high level of TNFRSF1A and Kim-1, and functional experiments revealed that the exogenous addition of TNF-α promoted kidney inflammation, dramatic injury, and specific depletion of TNFRSF1A would abrogate the injury.

Conclusions: The single-cell profiling of AKI microenvironment provides new insight for the deep understanding of molecular changes of AKI, and elucidates the mechanisms and developing new targeted therapies for AKI.

Keywords: acute kidney injury; intercellular crosstalk; microenvironment; renal tubular epithelial cells; trajectory analysis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acute Kidney Injury* / metabolism
Animals
Epithelial Cells / metabolism
Fibrosis
Kidney Tubules, Proximal / pathology
Mice
Reperfusion Injury* / pathology