Abstract: PURPOSE: To screen and verify the differentially expressed microRNAs (miRNAs) during the differentiation of human dental pulp cells (hDPCs) to odontoblasts induced by BMP-2. METHODS: The isolated hDPCs were cultured in vitro and induced by BMP-2. The levels of ALP, DMP-1 and DSPP were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). The potential characteristics of hDPCs were investigated by miRNA microarray and highly expressed miRNAs were selected with bio-information software for predicting target genes and their biological functions. Then the results were validated using qRT-PCR analysis for the selected miRNAs. Statistical analysis was performed using SPSS 18.0 software package. RESULTS: The expression of ALP, DSPP, and DMP-1 showed significantly higher levels in BMP-2 induced groups compared to the control group(P<0.05). A total of 36 miRNAs were changed (i.e. 20 miRNAs were up-regulated and 16 were down-regulated). The results of qRT-PCR were consistent with the microarray results. GO categories revealed that they were mainly associated with biological process(37.8%), cellular component (29%), molecular function(33%), while the function of other 0.2% genes remained unknown. CONCLUSIONS: This study identified differential expression of miRNAs in BMP-2-induced odontoblastic differentiation of hDPCs, thus contributing to further investigations of regulatory mechanisms and biological effect of target genes in BMP-2-induced odontoblastic differentiation of hDPCs.

Key words: Dental pulp cells, BMP-2, MiRNA, Odontoblasts, MiRNA Profile