[Age-related changes in differentiation of bone marrow mesenchymal stem cells and the activity of Notch signaling...

To explore the age-related changes in differentiation and proliferation of murine bone marrow mesenchymal stem cells (BMSCs) and the activity of Notch signaling pathway in vitro.

BMSCs were harvested from the whole bone marrow of young, adult and aged C57BL/6 mice and were evaluated for cell-surface protein expression using flow cytometry. After osteogenic and adipogenic induction, osteogenic and adipogenic differentiation ability of BMSCs was evaluated. Cell viability was analyzed by proliferation and migration assays. The expressions of Notch-related genes were analyzed by real-time PCR. The experimental data were analyzed with SPSS 19.0 software package.

Alizarin red S and Oil red O staining results indicated that the osteogenic ability of BMSCs gradually decreased with aging, while the adipogenic ability increased. Cell activity assays showed that the proliferative and migrated capacity did not decline with aging significantly, which suggested that the changes of osteogenic and adipogenic differentiation observed in aged BMSCs were not attributed to cell activity but to differentiation potential. Real-time PCR showed the aged cells exhibited significantly higher Notch signaling expression level than the younger ones (P＜0.05).

Decreased bone formation capacity and increased adipogenic differentiation ability were noted in aged BMSCs. At the same time, the activity of Notch signaling pathway shows an aging increase which would propose a new idea to restore the damaged osteogenic differentiation ability of aged BMSCs.