Contribution of different bone marrow-derived cell types in endometrial regeneration using an irradiated murine model

Abstract

Objective: To study the involvement of seven types of bone marrow-derived cells (BMDCs) in the endometrial regeneration in mice after total body irradiation.

Design: Prospective experimental animal study.

Setting: University research laboratories.

Animal(s): β-Actin-green fluorescent protein (GFP) transgenic C57BL/6-Tg (CAG-EGFP) and C57BL/6J female mice.

Intervention(s): The BMDCs were isolated from CAG-EGFP mice: unfractionated bone marrow cells, hematopoietic progenitor cells, endothelial progenitor cells (EPCs), and mesenchymal stem cells (MSCs). In addition three murine GFP(+) cell lines were used: mouse Oct4 negative BMDC multipotent adult progenitor cells (mOct4(-)BM-MAPCs), BMDC hypoblast-like stem cells (mOct4(+) BM-HypoSCs), and MSCs. All cell types were injected through the tail vein of 9 Gy-irradiated C57BL/6J female mice.

Main outcome measure(s): Flow cytometry, cell culture, bone marrow transplantation assays, histologic evaluation, immunohistochemistry, proliferation, apoptosis, and statistical analysis.

Result(s): After 12 weeks, histologic analysis revealed that uteri of mice with mOct4(-)BM-MAPCs and MSC line were significantly smaller than uteri of mice with uncultured BMDCs or mOct4(+) BM-HypoSCs. The percentage of engrafted GFP(+) cells ranged from 0.13%-4.78%. Expression of Ki-67 was lower in all uteri from BMDCs treated mice than in the control, whereas TUNEL(+) cells were increased in the EPCs and mOct4(+)BM-HypoSCs groups.

Conclusion(s): Low number of some BMDCs can be found in regenerating endometrium, including stromal, endotelial, and epithelial compartments. Freshly isolated MSCs and EPCs together with mOct4(+) BM-HypoSCs induced the greatest degree of regeneration, whereas culture isolated MSCs and mOct4(-)BM-MAPCs transplantation may have an inhibitory effect on endometrial regeneration.

Keywords: Bone marrow-derived cells; endometrial regeneration; murine model; stem cells.