Effects of TAZ, a transcriptional coactivator, on human dental pulp stem cell proliferation in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND:How to improve the proliferation of human dental pulp stem cells(hDPSCs)in vitro is of great importance in regenerative medicine. OBJECTIVE: To investigate the effect of TAZ, a transcriptional coactivator, on the proliferation of hDPSCs and its potential mechanisms. METHODS:hDPSCs were isolated from human dental pulps and cultured in vitro.The expression of TAZ in hDPSCs was detected by immunofluorescence method. Then, we knocked down the expression of TAZ in hDPSCs, and the proliferation of hDPSCs was measured by MTT and BrdU kit analysis respectively. The levels of CTGF and Cry61, which are the downstream target genes of TAZ, were detected by RT-qPCR and western blot assay. We also investigated the effect of TAZ on the levels of transforming growth factor-β (TGF-β) signaling proteins, Smad3 and Smad 4 by using western blot. RESULTS AND CONCLUSION: TAZ protein was expressed in hDPSCs. After the transfection by siTAZ for 24 hours, the mRNA and protein levels of TAZ were both significantly decreased. After the transfection by siTAZ for 24 and 48 hours, the proliferation of hDPSCs was obviously inhibited. Meanwhile, the mRNA and protein levels of CTGF and Cry61 were decreased by siTAZ transfection. The further research showed that TAZ silence also inhibited the expression of Smad3 and Smad 4, which belonged to the TGF-β signaling pathway. To conclude, TAZ may modulate the proliferation of hDPSCs through regulating the expression of CTGF and Cry61, and TGF-β-dependent signaling pathways may be involved in this regulation.