Mesenchymal Stem Cell in Mice Uterine and Its Therapeutic Effect on Osteoporosis

Abstract

Osteoporosis is a silent disease caused by low bone mineral density and is complicated by fractures. This study was designed to examine the differentiation of uterine stem cell-derived osteoprogenitor cells (UOPCs) both in vitro and in vivo , assessing their effectiveness in treating osteoporosis. CD271 + /CD45 − UOPCs were isolated from the endometrial tissue of inbred Balb/c mice through magnetic activated cell sorting. Stem cell differentiation assays were used for CD271 + /CD45 − UOPCs in vitro . In vivo , the UOPCs were implanted into mouse osteoporosis models through tail-vein injection for 8 weeks. Osteogenic differentiation was examined by X-rays and computed tomography (CT) scans. Enhanced green fluorescent protein (EGFP)-labeled UOPCs, obtained from C57BL/6-Tg (ACTb-EGFP) 1Osb/J mice, were used to assess cell survival in the osteoporosis model. The levels of osteogenic markers were assessed by enzyme-linked immunosorbent assay. In vitro , UOPCs were able to form into typical spheres and various differentiations. In vivo , implantation of UOPCs into osteoporosis model significantly increased bone mineral densities and bone microstructure parameters. The levels of a biochemical marker of bone metabolism, Semaphorin-3A , increased significantly. However, levels of receptor activator of nuclear factor kappa-B ligand decreased. Immunofluorescence staining of osteoporosis mice injected with green fluorescent protein+ UOPCs showed their survival for up to 7 days. In conclusion, stem cells with osteogenic differentiation potential can be isolated from uterine or endometrial tissue. These UOPCs can stably proliferate and differentiate in vitro or in vivo , which can inhibit bone resorption and osteoclast marker expression. In vivo , UOPCs significantly improved reduction in bone density caused by reduced estrogen levels. Such cell transplantation approach is potentially useful in the treatment of osteoporosis.