Effect of co-culture of bone-marrow mesenchymal stem cells and osteoblasts on proliferation of osteoblasts

Objective To investigate the effect of co-culture of bone-marrow mesenchymal stem cells(BMSCs) and osteoblasts on proliferation of osteoblasts.Methods BMSCs and osteoblasts were co-cultured according to different ratios of 1∶2(group A1),1∶4(group A2),1∶1(group A3),2∶1(group A4) and 4∶1(group A5).Culture of osteoblasts alone(group B1) or BMSCs(group B2) were taken as the controls.The ratios of the co-cultured cells were detected by flow cytometry.The growth curve of each group was determined by cell counting kit-8(CCK-8),and the mRNA expressions of alkaline phosphatase(ALP) and collagen type I were measured by RT-PCR.Results Co-culture of BMSCs and osteoblasts promoted the proliferation of osteoblasts,especially in group A2,which was obviously greater than that in group B1(P0.05).But there was no significant difference in mRNA expressions of ALP and collagen type I between groups of A2 and B1(P0.05).Conclusion Co-culture of BMSCs and osteoblasts can enhance the proliferation of osteoblasts,for which the best ratio of co-culture is 1∶4.