Bone marrow mesenchymal stem cells from Sprague-Dawley rats:aging inhibits cell proliferation and differentiation / 中国组织工程研究

ABSTRACT

BACKGROUND:Bone marrow mesenchymal stem cells are ideal as tissue engineering seed cells, but the proliferation and differentiation of mesenchymal stem cells in vitro is very different at different ages. Moreover, there are few reports on the association between age and the number of bone marrow mesenchymal stem cells. OBJECTIVE:To observe the difference in differentiation ability of bone marrow mesenchymal stem cells from rats at different ages. METHODS:We isolated, purified and amplified the mesenchymal stem cells from rat bone marrow in vitro by the whole bone marrow adherent culture;observed the morphological characteristics of mesenchymal stem cells under an inverted phase contrast microscope;detected cellsurface markers by flow cytometer. Then, mesenchymal stem cells were induced in vitro into osteoblasts and chondroblasts and verified. Passage 3 cells from rats at ages of 2, 4, 6, 8, 12 weeks and 10, 12 months were subjected to osteogenic induction at weeks 1, 2, 3. ELISA was used to determine osteocalcin content. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cells cultured in vitro were adherent and exhibited a fibroblast-like spindle shape. In vitro, cells proliferated quickly to form colonies. Flow cytometry showed that the cells were positive for CD29, CD90, but negative for CD45, and partial y expressed CD44. After osteogenic induction, cells were positive for alkaline phosphatase staining and alizarin red staining;after chondrogenic induction, cells were positive for alcian blue staining. Mesenchymal stem cells could be isolated and cultured by the method of bone marrow adherent culture in vitro. However, bone marrow mesenchymal stem cells from rats at different ages exhibit decreased proliferation and differentiation abilities with the increase of age through determination of osteocalcin content.