Single-cell analysis of endometrial proliferation and secretory phases in patients with endometriosis and normal population

The characteristic of endometriosis is that the endometrial tissue grows in non-endometrial parts such as the pelvis and ovaries, leading to infertility and chronic pain. However, its pathophysiology is still unclear. Using high-precision single-cell RNA sequencing, we analyzed the in-situ endometrium of 13 individuals with or without endometriosis, including the proliferative and secretory phases. We have meticulously generated a comprehensive single-cell atlas of the eutopic endometrium from patients with endometriosis. Comparative analysis with the healthy eutopic endometrium has elucidated that the epithelial cells of the ectopic tissue display marked immune-related phenotypes. We have identified the presence of an epithelial-to-mesenchymal transition (EMT) pathway between epithelial cells and fibroblasts within the endometrial tissue of individuals with endometriosis. Furthermore, our research has elucidated the intricate interactive dynamics between immune cells and fibroblasts, epithelial and endothelial cells, potentially shedding light on the underlying pathophysiological mechanisms contributing to endometriosis.