Effects Of Osteopontin In Mice Bone Marrow-derived Mesenchymal Stem Cells Differentiating Into Osteoblasts In Vitro

Objective Adult human stem cells that are intrinsic to various tissues have been described and characterized recently. These cells are capable of maintaining, generating, and replacing terminally differentiated cells within their own specific tissue as a consequence of physiologic cell turnover or tissue damage due to injury. Recent data suggest that adult stem cells generate differentiated cells beyond their own tissue boundaries, a process termed developmental plasticity. In this article we focus on in vitro models of adult stem cells derived from bone marrow and their potential therapeutic applications. Stem cells are defined as cells that have clonogenic and self-renewing capabilities and that differentiate into multiple cell lineages. It is demonstrated that bonestromal stem cells have multiple potential to differentiate into muscle,bone,cartilage,adipose,blood vessel endothelial,liver and neuron cells.BMSCs can be used as cell source in tissue engineering,cell implant and gene therapy with the possibility to be distributed todifferent tissue and organs normal circulation. They hold great promise in future therapeutic application in that they are easy to obtain, separate,expand and transfect, the procedure of bone marrow extraction is less harmful and the replantation induces no immune rejection. To explore the role of osteopontin (OPN) in the process of fracture healing mechanism, and to provide the exact theoretical basis for the future research in fracture healing.Method The bone marrow was separated from the bone of limbs of rats and was isolated and purified using adherence filtration. The passage cells of the third generation were divided into groups. BMSCs were cultured and divided into experimental group and control group. In the experimental group, the culture medium contained 0.2nmol/L OPN. Cell morphology was observed the light microscope, Cell growth curves were tested by cell number counting method, cell cycle was examined with flow cytometry. Alkaline phosphatase(ALP) stain and activity, osteocalcin (OCN) content were measured.Result The experimental group cells had osteoblasts-like morphology; Cell growth curve of OPN group moved rightward, Fluorescence at G0/G1 phase increased 13.17%(P< 0.01) and that at S phase decreased 74.93%(P< 0.01); ALP stain of experimental group cells was positive, and ALP activity and OCN content of experimental group cells increased greatly compared with that of control group.Conclusion 1.Adhering and screening method is a easy and reliable method to separate BMSCs.2. BMSCs can be obtained easily and have a strong osteogenic capacity, so BMSCs can be served as the seeding cells in the bone tissue engineering.3. OPN can improve the osteogenic differentiation of BMSCs.