Endometriotic lesions exert distinct metabolic activity compared to paired eutopic endometrium at a single-cell level

Eutopic endometrium (EuE) and endometriotic peritoneal lesions (ectopic endometrium, EcE) are heterogenous tissues according to the recent scRNA studies. We aimed to explore metabolic profile of cell populations in paired samples of EuE and EcE from four women with endometriosis. We found changes in the regulation of progesterone and estradiol signaling pathways in perivascular, stromal and endothelial cells of EcE compared to EuE, which might have a direct effect on cellular metabolism and contribute to cell proliferation and angiogenesis. The metabolic pathways were differentially regulated in perivascular, stromal and endothelial clusters, and metabolic pathway activity change between EcE and EuE was the highest for AMPK, HIF-1, glutathione metabolism, OXPHOS, and glycolysis/ gluconeogenesis. Remarkably, we identified co-activation of glycolysis and OXPHOS in perivascular and stromal cells of EcE compared to EuE. Previous studies reported a Warburg-like effect in endometriosis with a high use of glycolysis pathway over oxidative metabolism. Our observations might suggest the employment of both OXPHOS and glycolysis to meet the energy demands of proliferating cells in endometriotic lesions.