Estradiol treatment induces both shared and unique gene regulation and networks in adipose cell types of gonadectomized obese XX and XY mice

Obesity is driven by the pathological expansion and accumulation of adipose tissue and demonstrates sex differences. Estradiol (E2) is known to influence fat distribution and metabolism. However, a comprehensive understanding of the sex-specific effect of E2 on individual adipose cell types remains elusive. We measured adiposity and utilized single-cell RNA sequencing to dissect how E2 affects the molecular processes within gonadal adipose tissue from diet-induced obese, gonadectomized mice of both sexes (XX and XY) through differential gene expression, pathway enrichment, transcription factor enrichment, intracellular and intercellular network modeling, and human disease relevance analysis. We found striking sex- and cell-type-specific responses to E2 treatment. Accompanying more significant fat reduction under diet-induced obesity in XX mice, adipose stem and progenitor cells (ASPCs) of XX mice exhibited a stronger transcriptomic shift in response to E2 than ASPCs in XY mice, with altered expression of genes related to stemness and lipid metabolism. E2 broadly suppressed extracellular matrix (ECM) genes in both sexes, with more pronounced downregulation of collagen, glycoprotein, and metalloproteinase-related genes in XY preadipocytes, and reduced proteoglycan genes in XX mice. Macrophages also demonstrated heightened sensitivity to E2, showing trends in decreased proportion of lipid-associated macrophages, increased perivascular-like macrophages, and downregulated inflammatory and metabolic pathways in both sexes as well as sex-specific changes in immune genes. Furthermore, we identified strengthened macrophage to ASPC communications in XX mice and differential enrichment patterns of sex-biased E2-altered genes with human metabolic diseases. Our findings provide a cell-resolution, sex-specific understanding of E2’s profound impact on gonadal adipose tissue remodeling to guide sex-specific therapeutic interventions in obesity. Estrogen is a sex hormone that plays critical roles in both women and men, regulating not only reproduction but also how the body stores and uses fat. However, how individual types of cells respond to estrogen in females versus males remains unknown. Here, we analyzed how estrogen treatment affects individual cells and genes in visceral fat, the adipose depot surrounding internal organs and is tightly linked to metabolic diseases, in obese female and male mice. Our findings revealed that among the adipose cell types, stem-like cells that can form new fat cells and a specific type of immune cells called macrophages were particularly sensitive to estrogen in both sexes. Estrogen also caused more pronounced changes in females than in males, affecting both the number and the gene expression patterns of these cells. In female fat tissue, estrogen appeared to maintain more stem cells and reduce genes involved in fat cell differentiation and extracellular matrix remodeling. In macrophages of both sexes, estrogen lowered inflammation, though female mice showed additional fine-tuned control of immune and energy-related pathways and enhanced communication between adipose stem cells and macrophages. Lastly, estrogen-responsive genes were also linked to human metabolic disease/traits such as cholesterol levels, diabetes, and heart disease risks. Collectively, our findings support that estrogen shapes visceral fat tissue in a sex- and cell-type specific manner and point to key cell types and biological processes underlying differences in metabolic health and risk between men and women.