Background
Human bone marrow stromal cells (BMSCs) are belived to play a major role in bone formation source of osteogenitor cells. In osteoporosis, bone loss involves both increased osteoclastic bone resorption and decreased osteoblastic bone formation. Osteoporosis may be associated with increased oxidative cellular stress of free radicals in the progress of aging. Reactive Oxygen Species (ROS) enhance the osteoclastic activity, but the effect of ROS on osteoblastic function is unkown. Oxidative stress shortened the cellular replicative life span mediated by the erosion of telomeres. Telomere length decrease regularly with cell division and short telomeres induce the arrest in replicative senescence. We analyzed how oxidative stress effect the telomere length on the differentiation of human bone marrow stromal cells in ex vivo culture.
Method
Bone marrow was harvested from iliac crest. Mononuclear cells were separated using Ficoll-Hypaque, seeded in culture flasks including α-MEM at a density of 4×105 cells/ml, and incubated in a humidified atmosphere at 37℃ with 5% CO2. We treated with hydrogen peroxide (H2O2), Xanthine/Xanthine Oxidase (X/XO) and assessed their effects on intracellular oxidative stress, cell viability and telomere length. Intracellular oxidative stress was measured by 2' 7'-Dichlorofluorescin diacetate (DCF) and cell viability was measured by MTT assay. Telomere length was assessed by southern blot analysis during secondary culture.
Result: Oxidative stress (H2O2 and X/XO) increased intracellular oxidative stress as determined by DCF. Treatment with oxidative stress causes a decrease in the cell viability by dose and time dependently. But, present study did not detect any significant change with the addition of antioxidant, and telomere length was not shortened by oxidative stress.
Conclusion
The present study suggests that oxidative stress decreased cell viability. Induction of Reactive Oxygen Species (ROS) generation influence
