[Biological characteristics of sheep peripheral blood mesenchymal stem cell]

OBJECTIVE: To obtain eripheral blood mesenchymal stem cells (PBMSCs) from sheep and rabbits by continuous mobilization of granulocyte colony-stimulating factor (G-CSF), and by comparing the success rates, cell yields and biological characteristics of the two sources of PBMSCs, and to provide the experimental basis for the preclinical study of PBMSCs transplantation to repair articular cartilage injury and cartilage tissue engineering. METHODS: Through morphological characteristics, flow cytometry analysis of its surface markers, and induction of trilineage differentiation of the two cells in vitro (ie: adipogenic differentiation, osteogenic differentiation, chondrogenic differentiation), the obtained cells were finally confirmed to be PBMSCs. The colony-forming units (CFUs) and the acquisition success rates of the two PBMSCs were counted and compared, and the production of the second generation of the two PBMSCs was counted and compared by hemocytometer, and the cell counting kit-8 was used to detect the doubling time of the two PBMSCs, and the results of trilineage differentiation were quantitatively analyzed by image processing. RESULTS: Microscopically, the PBMSCs of fusiform sheep and rabbits were arranged in fish group, and the second generation of sheep and rabbit PBMSCs expressed CD44 and CD90, but not CD34 and CD45. The induction of trilineage differentiation of the two cells in vitro were successful. The CFUs of primary sheep and rabbits PBMSCs were: 7.27±1.56, 5.73±1.62, and the success rate of acquisition of sheep and rabbits PBMSCs were 78.57% and 36.67%. The number of the second-generation sheep and rabbits PBMSCs that obtained per milliliter of peripheral blood were: 29 582±2 138, 26 732±2 286, and the cell doubling times (h) of the third-generation sheep and rabbits PBMSCs were: 22.32±0.28, 33.21±0.64, the cell doubling time (h) of the fourth generation sheep and rabbits PBMSCs were: 23.62±0.56, 35.30±0.38, and the quantitative lipid ratio of sheep and rabbit PBMSCs were: 7.77%±3.81%, 17.05%±1.52%, sheep and rabbit PBMSCs chondroglobus acid mucopolysaccharide positive ratios were: 11.67%±0.53%, 8.14%±0.57%. There were statistical differences among the above groups (P < 0.05). CONCLUSION: The continuous mobilization of G-CSF to obtain sheep PBMSCs is more efficient. Sheep PBMSCs have more abundant yield and stronger proliferation ability.Sheep PBMSCs can produce more acidic mucopolysaccharides and have lower adipogenic abi-lity under appropriate conditions. Sheep PBMSCs have good research prospects in repair of articular cartilage injury with autologous stem cell transplantation and preclinical animal in vivo experiment of cartilage tissue engineering.This experiment provides further experimental basis for this kind of research.