Background: Endometrial injury is considered the major cause of female infertility. Traditional therapies such as estrogen substitution therapy are not satisfactory due to individual variation in response to treatment, thereby warranting the use of alternative strategies such as stem cell therapy. Transplantation of stem cells, such as umbilical cord mesenchymal stem cells (UCMSCs), has been shown to improve endometrial healing. However, due to the effect of the intrauterine environment, the therapeutic effect of UCMSCs is limited, and its efficacy is unstable. HOXA10, encoded by the HOXA10 gene, plays an important role in endometrium morphology maintenance, proliferation, differentiation, and embryo implantation. Moreover, UCMSCs do not show HOXA10 expression. Objective: Our study aimed to evaluate the therapeutic effects of HOXA10-transfected UCMSCs on endometrial injury repair in vivo. Method: First, we established T10-UCMSCs (UCMSCs transfected with HOXA10) for transplantation. To establish the endometrial injury model, we injected 95% ethanol into the uterine cavity and transplanted T10-UCMSCs into the uterine cavity from the cornua uteri. Fourteen days later, uteri were collected for histological and biochemical analysis of endometrial growth and receptivity. Result: Our results showed the endometrial receptivity was better in T10-UCMSCs group than in UCMSCs group, suggesting that HOXA10 could enhance the repairing ability of UCMSCs in the endometrium injury repair. More importantly, the fertility test showed that more embryos were implanted in the T10-UCMSCs group. Conclusion: Our results suggest that UCMSCs with HOXA10 expressing could improve the therapeutic effects on endometrial injury repairing.

Thin endometrium (TE) is a heterogeneous uterine disorder characterized by TE that results in infecundity. Patients with TE are usually associated with menstrual abnormalities and suffer from pelvic pain. A number of treatments have been employed to promote endometrial growth, but none has been validated effective. With the development of stem cell therapy, better means for TE treatment to improve endometrium, thus restoring its function become possible. Studies in TE mouse models have shown that stem cell implantation could improve pregnancy. However, the efficiency is relatively low and the safety for its clinical applications remains unclear. Here, we summarize recent progresses on the clinical application of stem cells for TE treatment, which would provide valuable references for stem cell therapy in TE patients.