Interference of octamer-binding transcription factor 4A and its effect on the proliferation and multiple differentiation of human dental pulp cells

Abstract

To investigate the expression of octamer-binding transcription factor 4A(Oct4A) in human dental pulp cells(DPC)and the effect of Oct4A on the proliferation and multiple differentiation ability of DPC. Expression of Oct4A in DPC was detected by realtime quantitative PCR(RT-qPCR). siRNA-Oct4A was constructed and transfected (50 nmol/L) into DPC with Lipofectamine(TM) RNAiMAX for 24, 48, 72, 96 and 120 h. The proliferation rate of DPC was examined using cell counting kit 8 (CCK-8) assay. The alizarin red staining was used to observe the formation of calcification nodules in DPC with 14 d of osteogenic induction, and oil red O staining to observe the formation of lipid droplet in DPC with 14 d of adipogenic induction. The expression of osteogenesis-related genes dentin sialophosphoprotein (DSPP) and adipogenesis-related genes lipoprotein lipase (LPL) was detected using RT-qPCR and Western blotting. The expression of Oct4A reached the peak in P3 DPC (2.10 ± 0.10), which was 2.10 times as much as that in P1 (P = 0.000 vs. P1 and P7), and decreased along passages. The interference efficiency of DPC transfection peaked at 72 h (69.7%). Compared with control group and negative control group (IR-siRNA), the proliferation rate and multiple differentiation ability of DPC in interference group (Oct4A-siRNA) were downregulated (P = 0.000), and DSPP and LPL in DPC from interference group significantly decreased (P = 0.000). The interference of Oct4A significantly downregulated the cell proliferation rate and multilineage differentiation capability of DPC.