CXCR4 Has the Potential to Enhance Bone Formation in Osteopenic Rats

Osteoporosis is characterized by reduced bone mass and aberrant bone microarchitecture, thus increasing susceptibility to fracture due to reduced strength and quality. The aims of this study were to investigate the role of CXCR4 transfected on stem cell homing and osteogenic characteristics in osteopenic rats, particularly elucidating the effect on cell migration. Methods: Mesenchymal stem cells (MSCs) were harvested from young, and ovariectomized animals and transfected with CXCR4; these cells were administered intravenously in ovariectomized rats. Micro CT and mechanical testing were completed after 12 weeks. Results: Rats injected with young CXCR4 transfected cells had significantly higher bone mineral density (BMD) compared to placebo injected rats (p<0.05). Rats injected with ovariectomized CXCR4 transfected cells had higher BMD compared to those injected with saline or nontransfected cells (p<0.04). L4 vertebral stiffness was significantly higher in rats treated with young CXCR4 transfected cells compared to all other groups (p<0.05). Conclusion: CXCR4 genetically modified cells from young and ovariectomized sources improve some aspects of bone formation in the ovariectomized model of osteoporosis and, thus, may play a role in patient treatment regimens.