Three-Dimensional Organoid-like Co-Culture of Human Endometrial Endothelial and Stromal Cells to Study Endometriosis-Associated Responses.

Three-dimensional (3D) endothelium-stromal co-cultures were established using human endometrial cells from biopsy of healthy women (n = 13) and serum samples from both healthy and endometriotic women (n = 5). For 3D construction, stromal cells were mixed with extracellular matrix components, followed by endothelial cell seeding. Morphological analysis confirmed the organization of tissue-like structures. Immunofluorescence and flow cytometry verified the expression of specific stromal and endothelial markers (Cytokeratin, Vimentin, Insulin-like growth factor-binding protein 1, and von Willebrand factor). Cell viability and proliferation increased over time, with minimal cell death. To test functional responsiveness, these co-cultures were exposed to inflammatory serum from endometriotic patients. After 48 h, cytometric bead array showed elevated levels of IL-1β, IL-6, and IL-8 in cultures treated with inflammatory serum, indicating preserved functional activity and responsiveness. By allowing detailed investigation of functional endometrial states within a physiologically relevant cellular network, this approach provides a valuable organoid-like tool to explore conditions such as implantation failure and infertility and to study the cellular interactions underlying reproductive pathologies.