Preclinical Study of Cell Therapy for Osteonecrosis of the Femoral Head with Allogenic Peripheral Blood-Derived Mesenchymal Stem Cells

PURPOSE: To explore the value of transplanting peripheral blood-derived mesenchymal stem cells from allogenic rabbits (rPBMSCs) to treat osteonecrosis of the femoral head (ONFH). MATERIALS AND METHODS: rPBMSCs were separated/cultured from peripheral blood after granulocyte colony-stimulating factor mobilization. Afterwards, mobilized rPBMSCs from a second passage labeled with PKH26 were transplanted into rabbit ONFH models, which were established by liquid nitrogen freezing, to observe the effect of rPBMSCs on ONFH repair. Then, the mRNA expressions of BMP-2 and PPAR-γ in the femoral head were assessed by RT-PCR. RESULTS: After mobilization, the cultured rPBMSCs expressed mesenchymal markers of CD90, CD44, CD29, and CD105, but failed to express CD45, CD14, and CD34. The colony forming efficiency of mobilized rPBMSCs ranged from 2.8 to 10.8 per million peripheral mononuclear cells. After local transplantation, survival of the engrafted cells reached at least 8 weeks. Therein, BMP-2 was up-regulated, while PPAR-γ mRNA was down-regulated. Additionally, bone density and bone trabeculae tended to increase gradually. CONCLUSION: We confirmed that local transplantation of rPBMSCs benefits ONFH treatment and that the beneficial effects are related to the up-regulation of BMP-2 expression and the down-regulation of PPAR-γ expression.

Verification of multipotential mesenchymal stem cell presence in peripheral blood of rabbits / 中国实验血液学杂志

The aim of this study was to verify the presence of multipotential mesenchymal stem cells in peripheral blood (PBMSC) of rabbits. For mobilization, granulocyte-colony-stimulating factor 30 µg/(kg·d) was injected into New Zealand White rabbits subcutaneously for 6 d, then the PBMSC were isolated from peripheral blood of rabbits by density gradient centrifugation and adhesive culture. The morphology of cell proliferation was observed by microscopy, the proliferative curve of cells was drawn. The phenotypes of PBMSC were detected by flow cytometry, the differential capability of PBMSC into osteocytes, chondrocytes and adipocytes was identified. The results showed that the morphology of subcultured PBMSC were spindle or polygonal shaped, and cell population doubling time was 37.4 h. The isolated PBMSC expressed mesenchymal marker CD29, but not expressed hematopoietic marker CD14. Under specific induction conditions, PBMSC demonstrated multipotency to differentiate into osteocytes, chondrocytes and adipocytes. It is concluded that PBMSC are successfully isolated from peripheral blood and cultured, and their multipotential capability of differentiation into osteocytes, chondrocytes and adipocytes are verified.