Single-cell transcriptomics reveal the microenvironment landscape of perfluorooctane sulfonate-induced liver injury in female mice

Epidemic and animal studies have reported that perfluoroalkyl and polyfluoroalkyl substances (PFASs) are strongly associated with liver injury; however, to date, the effects of PFASs on the hepatic microenvironment remain largely unknown. In this study, we established perfluorooctane sulfonic acid (PFOS)–induced liver injury models by providing male and female C57BL/6 mice with water containing PFOS at varying doses for 4 weeks. Hematoxylin and eosin staining revealed that PFOS induced liver injury in both sexes. Elevated levels of serum aminotransferases including those of alanine aminotransferase and aspartate transaminase were detected in the serum of mice treated with PFOS. Female mice exhibited more severe liver injury than male mice. We collected the livers from female mice and performed single-cell RNA sequencing. In total, 36,529 cells were included and grouped into 10 major cell types: B cells, granulocytes, T cells, NK cells, monocytes, dendritic cells, macrophages, endothelial cells, fibroblasts, and hepatocytes. Osteoclast differentiation was upregulated and the T cell receptor signaling pathway was significantly downregulated in PFOS-treated livers. Further analyses revealed that among immune cell clusters in PFOS-treated livers, Tcf7+CD4+T cells were predominantly downregulated, whereas conventional dendritic cells and macrophages were upregulated. Among the fibroblast subpopulations, hepatic stellate cells were significantly enriched in PFOS-treated female mice. CellphoneDB analysis suggested that fibroblasts interact closely with endothelial cells. The major ligand–receptor pairs between fibroblasts and endothelial cells in PFOS-treated livers were Dpp4_Cxcl12, Ackr3_Cxcl12, and Flt1_complex_Vegfa. These genes are associated with directing cell migration and angiogenesis. Our study provides a general framework for understanding the microenvironment in the livers of female mice exposed to PFOS at the single-cell level.