Effect of different proportions of bone marrow mesenchymal stem cells and endothelial cells on osteogenesis / 中华口腔医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the effect of co-culture system of bone marrow mesenchymal stem cells (BMSC) and vascular endothelial cells (EC) on osteogenesis.</p><p><b>METHODS</b>BMSC were isolated by whole bone marrow centrifugal adherent method. Then BMSC were induced into EC with induced medium. Co-culture system in different proportions of BMSC and EC (100, 101, 82, 73, 55, 37, 28, 110, 010) were further evaluated. The cell growth level of BMSC was examined. The CD44 expression of BMSC and von willebrand factor (vWF) expression of vascular EC were examined by immunofluorescence. Furthermore, calcium nodules exhibited by alizarin red staining, alkaline phosphatase activity, and the expression of osteogenic genes by reverse transcription-quantitative PCR (RT-qPCR) were observed to validate the osteogenesis of co-culture system.</p><p><b>RESULTS</b>The growth curve of P3 passage of BMSC demonstrated the doubling time of BMSC was 39.9 h. The positive specific markers of BMSC and EC showed efficient induction. Although the calcium nodules ratio of the co-culture [group 73 (19.0 ± 3.0) and group 55 (20.8 ± 2.9)] was not significantly different (P > 0.05), but higher than that of other co-culture groups with a significant difference (P < 0.01). Alkaline phosphatase activity was increased with prolonged induction of osteogenic medium. While alkaline phosphatase activity of group 100 (16.84 ± 0.82), group 101 (15.86 ± 3.10), group 82 (16.37 ± 1.33), group 73 (17.99 ± 1.98), and group 55 (17.49 ± 0.87) did not show significant difference after osteogenic induction for 7 days (P > 0.05), but significantly higher than that of other co-culture groups (P < 0.05). The co-culture ratio of 73 (33.74 ± 0.99) was slightly higher than that of 55 (31.09 ± 0.87), but significantly higher than that of other groups (P < 0.01). Moreover, the osteocalcin (OCN) and runt-related transcription factor 2 (RUNX2) expression of group 73 was significantly higher than that of other groups.</p><p><b>CONCLUSIONS</b>The EC that derived from BMSC can promote the BMSC differentiate into osteoblasts. The co-culture system of BMSC and EC with the ratio of 73 increases the alkaline phosphatase activity and facilitates the expression of osteogenic genes.</p>