Mapping the hepatic regulatory landscape of estradiol in gonadectomized obese female and male mice at single-nucleus resolution

Abstract Background Obesity is a prevalent, systemic metabolic disease affecting not only various adipose depots but also the liver, where lipid accumulation results in metabolic dysfunction-associated fatty liver disease, dyslipidemia, and insulin resistance. While estradiol (E2) has been known to be hepatoprotective for glucose and lipid metabolism in females, whether E2’s effects on individual liver cell types are shared between sexes or are sex-specific with obesity remains poorly defined. Methods We performed single-nucleus RNA sequencing on liver tissue of E2-treated obese, gonadectomized male (XY) and female (XX) mice with diet-induced obesity to evaluate the sex-concordant and discordant effects of chronic E2 treatment. Differential gene expression, pathway analysis, intracellular and intercellular regulatory network modeling, and human metabolic disease/trait association analysis were conducted. Results E2-induced transcriptional effects among hepatocyte subtypes were largely sex-concordant in both males and females, along with sex-specific E2 changes. In pericentral hepatocytes, E2 concordantly reduced the expression of genes involved in insulin resistance, FOXO signaling, and lipid biosynthesis; in periportal hepatocytes, E2 treatment enhanced cholesterol efflux genes and suppressed oxidative stress response genes. XY-specific effects of E2 included additional suppression of lipid and energy metabolic pathways in pericentral hepatocytes and oxidative phosphorylation in periportal hepatocytes, while in XX mice E2 showed unique regulation of glucose and lipid utilization programs. Network analysis revealed that E2-responsive genes in hepatocyte subtypes in both sexes showed enriched transcription factors associated with estrogen receptor signaling and lipid sensing and metabolism, alongside sex-specific regulators. Intercellular signaling affected by E2 showed more changes in XY mice than in XX mice across hepatocyte subtypes. Lastly, while E2-responsive genes in hepatocyte subtypes of both sexes were enriched for human genetic signals associated with lipid profiles and coronary artery disease, we also identified sex-specific associations, such as the link of E2-downregulated genes in XY hepatocytes to body mass index in men. Conclusions Our findings revealed that chronic E2 administration remodels gene regulatory programs in individual liver cell types through both shared and sex-specific mechanisms, highlighting the importance of considering sex chromosome-dependent E2 responses when developing therapeutic strategies for obesity and associated hepatic metabolic dysfunction.