[Study on the differentiation of marrow mesenchymal stem cells of the rats mediated by bone morphogenetic protein 2].

OBJECTIVE: To explore the effect of age and gene therapy on the differentiation of marrow mesenchymal stem cells (MSCs) of the rats. METHODS: MSCs from the young (1-month-old), adult (9-month-old), and the aged (24-month-old) rats were expanded in culture and infected with adenovirus mediated human bone morphogenetic protein 2 gene (Ad-BMP-2). The expression of BMP-2 and osteoblastic markers such as alkaline phosphatase (ALP), collagen I (Col I), bone sialoprotein (BSP) and osteopontin (OPN) were assayed during the process of differentiation. Their abilities to induce ectopic bone formation in nude mice were also tested. RESULTS: There was no significant difference in the expression of BMP-2 among the 3 groups. ALP activity assay and semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) demonstrated that there were no significant differences in the expression of osteoblastic markers ALP, Col- I, OPN and BSP among the 3 groups. Histomorphometric analysis indicated that there were no significant differences in the volume of the newly formed ectopic bones in nude mice among the 3 groups. CONCLUSION: MSCs obtained from the aged rats can restore their osteogenic activity following human BMP-2 gene transduction,therefore provides an alternative to treating the aged bone disease.