Objective      To determine the role of human dental pulp stem cells (HDPSCs) in the proliferation and osteogenic differentiation of human dental follicle stem cells (HDFSCs) under co-culture in vitro.       Methods      ①HDFSCs and HDPSCs were isolated

cultured and identified by a modified tissue block digestion

immunohistochemistry

flow cytometry and multilineage inducement. ②Cell culture chamber(Transwell) with pore size of 0.4 μm in diameter were used to facilitate the co-culture system of HDFSCs and HDPSCs in vitro. ③CCK-8 assay was used to test the changes of proliferative activity of HDFSCs; ④ In 1 week after in vitro co-culture system of HDFSCs and HDPSCs

the expression of several osteoblast marker genes including the alkaline phosphatase (ALP)

runt-related transcription factor 2 (Runx2)

osteopontin (OPN)

bone sialoprotein (BSP) and collagen type 1 (Col-1) were measured with qRT-PCR.       Results      ①HDFSCs and HDPSCs were isolated

cultured and identified successfully. ②Starting from the fourth day

HDFSCs in the co-culture group showed a higher proliferative activity than that in the control group (P0.05). ③Compared with the control group

there were significant increases in the relative mRNA levels of ALP

Runx2

OPN

BSP and Col-1 (P0.05) in the co-culture group.       Conclusion      Co-culture with HDPSCs stimulates the proliferous activity and osteogenic differentiation in HDFSCs.