Development of an in vitro mouse cultured uterine tissue model for the endometrial regenerative therapy

The endometrium is a characteristic structure that undergoes sequential phases involving regeneration and shedding of the functional area. It is believed that the stroma and stem cells found in the endothelium's basal layer are what cause regeneration. This process is impacted by numerous endometrial diseases which decrease the fertility. The absence of readily available animal‒level models is the fundamental constraint on the research into the regenerative treatment. This paper presented an air‒liquid culture model, established to investigate the suitable conditions for maintaining the survival of mouse uterine tissue in vitro. The submerged culture model was used as a control. The culture lasted for 16 days. The evaluations of the structure (H & E staining), viability (live/dead staining), and function (embryo implantation) of the uterine tissue were performed to confirm the efficacy of the model. The obtained results showed that the mouse uterine tissues cultured in an air‒liquid condition recovered their tissue structure clearly, remained stable throughout the survey up until day 12, and displayed impaired degradation on the 16th day. On the other hand, by the 12th day, the submerged culture model had clearly degraded. Additionally, compared to the submerged culture model, the viability of tissue cultured under air‒liquid conditions demonstrated the superiority with the P-value of 0.05. Only the tissues, cultured in an air‒liquid environment, showed the embryos attaching to the endometrium's surface. In summary, the air‒liquid culture conditions supported the maintenance of a stable tissue structure for 12 days. This model could be suitable for the study of therapies for mouse‒damaged endometrial tissue in vitro with a duration of up to three estrous cycles.