The Effect of NRAGE on cell cycle and apoptosis of human dental pulp cells and MDPC-23.

OBJECTIVES Neurotrophin receptor-mediated melanoma antigen-encoding gene homology (NRAGE) is an important regulator of proliferation, cell cycle arrest and apoptosis. Our previous study showed that NRAGE is an important regulator of proliferation and odontogenic differentiation of mouse dental pulp cells. This study aimed to investigate the effects of NRAGE on the cell cycle and apoptosis on human dental pulp cells (hDPCs) and MDPC-23. MATERIALS AND METHODS Cells were infected by recombinant lentivirus to stably knockdown the expression of NRAGE, then the biological effects of NRAGE on the MDPC-23 was detected. The cell cycle distributions and apoptosis of hDPCs and MCPC-23 were performed by flow cytometric analysis. Simultaneously, the cell cycle and apoptosis were also detected after cells treated with IKK inhibitor. RESULTS The mRNA and protein levels of NRAGE decreased significantly after infected by recombinant lentivirus. Knockdown of NRAGE inhibited the apoptosis in hDPCs and MCPC-23. Knockdown of NRAGE show significantly G0G1 arrest in hDPCs, while no significantly difference in MDPC-23. Meanwhile, Knockdown of NRAGE activated the NF-κB signaling pathway. After treated with IKK inhibitor, the effect of NRAGE knockdown on apoptosis was reversed in both hDPCs and MDPC-23. CONCLUSION NRAGE is a potent regulator for cell cycle and apoptosis of hDPCs. Knockdown of NRAGE inhibited apoptosis of hDPCs and MDPC-23 through the NF-κB signaling pathway.