Hepatic inflammation after exposure to a mixture of low-dose arsenic and cadmium in a murine model of fatty liver disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global health burden and a major contributor to chronic liver disease. Evidence suggests arsenic (As) and/or cadmium (Cd) exposure may influence MASLD development, yet the effects of chronic low-dose metal mixtures on hepatic inflammation and immune responses remain unclear. Using the apolipoprotein E-knockout mouse model, we examined low-dose As and Cd exposure in male and female mice. We focused on hepatic steatosis and inflammation. Steatosis-related changes were assessed via lipid metabolism gene expression and PLIN2 levels. No significant changes were observed in males; however, females exposed to the metal mixture showed increased PLIN2 expression. In contrast, males exhibited an inflammatory phenotype following combined exposure. High-plex single-cell imaging (PhenoCycler) in male livers revealed increased Ki67+ hepatocytes, enhanced β-catenin signal, and elevated CD8+ T-cell infiltration, indicating enhanced proliferation and immune activation. These findings suggest sex-dependent responses to low-dose As and Cd, with females showing subtle steatotic changes and males a pronounced inflammatory signature. Collectively, combined metal exposure induces hepatic priming in both sexes; males show an increased inflammatory response with cellular proliferation in the absence of overt steatosis or fibrosis, whereas females demonstrate increased steatosis without inflammation or fibrosis.