Single-cell transcriptomic insights into endosulfan-induced liver injury: Key pathways and inflammatory responses.

Background and aims: Environmental pollutants, particularly organochlorine insecticides like endosulfan (ENDO), are increasingly linked to liver toxicity and related diseases. Despite its widespread historical use, the mechanisms underlying ENDO-induced liver damage remain poorly understood. This study aims to elucidate the cellular and molecular mechanisms of ENDO-induced hepatotoxicity. Methods: C57BL/6 mice were exposed to ENDO for two weeks. Single-cell RNA sequencing (scRNA-seq) was subsequently performed on mouse livers to explore ENDO-induced hepatotoxicity at the single-cell level. Differentially expressed genes (DEGs) across cell types and treatments were identified and then subjected to pathway enrichment to uncover key biological processes affected by ENDO. Transcription factor (TF) regulatory network, pseudotime trajectory, and cellular communication analysis were used to explore the molecular and cellular changes after ENDO exposure. Results: ENDO not only caused direct hepatocyte injury but also activated hepatic stellate cells and lymphocytes, triggering inflammatory responses with upregulation of multiple key chemokines and cytotoxic genes. Additionally, ENDO exposure led to the recruitment and activation of myeloid cells, contributing to the inflammatory milieu. An increase in intercellular communication and changes to the hepatic microenvironment, especially the interaction between activated hepatic stellate cells and CD8 Conclusions: This study provides new insights into the cellular and molecular mechanisms underlying liver injury induced by organochlorine insecticides like ENDO. Key genes and pathways involved in ENDO-associated liver toxicity have been identified at a single-cell resolution. These findings suggest that altered cellular communications and inflammatory responses may play pivotal roles in the pathogenesis of ENDO-induced liver injury.