Single-cell RNA seq identifies Plg-RKT-PLG as signals inducing phenotypic transformation of scar-associated macrophage in liver fibrosis

Yuanru Yang; Weiyang Li; Chang Liu; Jing Liu; Lin Yang; Wenhui Yue; Le Yang; Renmin Xue; Kai Zhang; Hang Zhang; Na Chang; Liying Li

doi:10.1016/j.bbadis.2023.166754

Single-cell RNA seq identifies Plg-R_KT-PLG as signals inducing phenotypic transformation of scar-associated macrophage in liver fibrosis

Biochim Biophys Acta Mol Basis Dis. 2023 Aug;1869(6):166754. doi: 10.1016/j.bbadis.2023.166754. Epub 2023 May 18.

Authors

Yuanru Yang¹, Weiyang Li¹, Chang Liu¹, Jing Liu¹, Lin Yang¹, Wenhui Yue¹, Le Yang¹, Renmin Xue¹, Kai Zhang¹, Hang Zhang¹, Na Chang², Liying Li³

Affiliations

¹ Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China.
² Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China. Electronic address: changna@ccmu.edu.cn.
³ Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China. Electronic address: liliying@ccmu.edu.cn.

PMID: 37207518
DOI: 10.1016/j.bbadis.2023.166754

Abstract

Hepatic macrophages play a central role in liver fibrosis. Scar-associated macrophages (SAMs), a recently identified subgroup of macrophages, play an important role in this process. However, the mechanism by which SAMs transform during liver fibrosis is still unclear. In this study, we aimed to characterize SAMs and elucidate the underlying mechanism of SAM transformation. Bile duct ligation (BDL) and carbon tetrachloride (CCl₄) were used to induce mouse liver fibrosis. Non-parenchymal cells were isolated from normal/fibrotic livers and were analyzed using single cell RNA sequencing (scRNA-seq) or mass cytometry (CyTOF). The glucan-encapsulated siRNA particles (siRNA-GeRPs) was employed to perform macrophage selective gene knockdown. The results of scRNA-seq and CyTOF revealed that SAMs, which derived from bone marrow-derived macrophages (BMMs), accumulated in mouse fibrotic livers. Further analysis showed that SAMs highly expressed genes related to fibrosis, indicating the pro-fibrotic functions of SAMs. Moreover, plasminogen receptor Plg-R_KT was highly expressed by SAMs, suggesting the role of Plg-R_KT and plasminogen (PLG) in SAM transformation. In vitro, PLG-treated BMMs transformed into SAMs and expressed SAM functional genes. Knockdown of Plg-R_KT blocked the effects of PLG. In vivo, selective knockdown of Plg-R_KT in intrahepatic macrophages of BDL- and CCl₄-treated mice reduced the number of SAMs and alleviated BDL- and CCl₄-induced liver fibrosis, suggesting that Plg-R_KT-PLG played an important role in liver fibrosis by mediating SAM transformation. Our findings reveal that SAMs are crucial participants in liver fibrosis. Inhibition of SAM transformation by blocking Plg-R_KT might be a potential therapeutic target for liver fibrosis.

Keywords: Liver fibrosis; Mass cytometry; Plasminogen receptor KT; Scar-associated macrophage; Single cell RNA sequencing.

Publication types

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

MeSH terms

Animals
Cicatrix* / pathology
Fibrosis
Liver Cirrhosis / genetics
Liver Cirrhosis / pathology
Macrophages / pathology
Mice
Plasminogen* / genetics
Receptors, Cell Surface / genetics
Single-Cell Gene Expression Analysis

Substances

Plasminogen
Receptors, Cell Surface
PLG-R(KT) protein, mouse