Single cell RNA sequencing reveals the reshaping effect of perfluorooctanoic acid on the intestinal microenvironment of mice.

Perfluorooctanoic acid (PFOA), a prevalent perfluorinated compound pollutants, has been implicated in the development of various gastrointestinal disorders. However, the specific PFOA-induced intestinal microenvironment alterations remain poorly characterized. In this study, we established a chronic PFOA toxicity model in C57BL/6 mice of both sexes through exposure to PFOA at doses of 0, 1, 5, and 10 mg/kg/day. Single-cell RNA sequencing (scRNA-seq) was performed on the small intestine tissues from female mice, and key findings were validated through flow cytometry and immunohistochemistry. Histopathological analysis revealed that PFOA induced intestinal damage in both sexes, with a more severe impact observed in female mice. scRNA-seq analysis demonstrated that PFOA treatment triggered abnormal proliferation of intestinal epithelial cells, particularly the expansion of Adahigh enterocyte cells, suggesting their potential role in injury repair process. Furthermore, PFOA exposure induced significant remodeling of the intestinal immune microenvironment, characterized by decreased overall lymphocyte infiltration, heightened activation of remaining cytotoxic CD8+ T cells, and a notable increase in proliferative CD8+ T cells. A significant reduction in FOXP3+ regulatory T cells further contributed to a pro-inflammatory shift within the T cell population. Cell-cell interaction analysis revealed enhanced macrophage-CD8+ T cell communication via the CCR1-CCL5 axis, suggesting a synergistic role in driving inflammatory responses. This study presents a comprehensive analysis of PFOA-induced intestinal microenvironment remodeling at single-cell resolution, providing novel insights into the pathophysiological mechanisms underlying PFOA-associated intestinal diseases. SYNOPSIS: Minimal research exists on PFOA-induced intestinal microenvironment changes. The study shows that abnormal hyperplasia and dysfunction of intestinal epithelial cell, along with immuno microenvironment dysregulation, create an inflammatory environment, potentially linked to PFOA-induced systemic toxicity.