Conclusion
The beneficial effect of hPBMCs on endometrium may suggest their clinical feasibility for the safe treatment of infertile patients with persistently thin endometrium.
Methods
To assess the in vitro effect of hPBMC, the human primary endometrial epithelial cell lines SNU-685 and SNU-1077 were co-cultured with or without 1 × 105 hPBMCs for 24 h. To evaluate the in vivo effect, either 1 × 105 hPBMCs in PBS or PBS alone were injected into the left uterine horn of nonobese diabetic-severe combined immune-deficient mice, and the right untreated uterine horn was used as control.
Results
Co-culture with hPBMCs stimulated significant proliferation in both SNU-685 and SNU-1077 cell lines (p = 0.002 and 0.044, respectively). Moreover, treatment with hPBMCs significantly increased the thickness in all parts of the endometrium compared with that in the untreated control uterine horn (proximal: 1.69 ± 0.19 vs. 1.00 ± 0.10, p = 0.009; middle: 1.51 ± 0.14 vs. 1.00 ± 0.12, p = 0.010; distal: 1.72 ± 0.22 vs. 1.00 ± 0.12, p = 0.003, respectively). Compared with the PBS injection group, the hPBMC injection group had significantly thickened endometrium in the middle (p = 0.036) and distal segments (p = 0.002) of the uterine horn. Immunohistochemical analysis revealed the presence of exogenously injected hPBMCs in the uterus of recipient mice. hPBMC-recipient mice had cyclic uterus with normal histology in the endometrium. Limitations: hPBMCs were not applied directly to a mouse model with thin endometrium, so further study is needed.