Changes in the MicroRNA Profile of the Mandible of Ovariectomized Mice.

BACKGROUND/AIMS: In postmenopausal women, a decrease in bone mineral density (BMD) at the hip and spine is associated with an increased risk of tooth loss, possibly caused by the loss of the alveolar bone. The present study explored the effect of the ovariectomy (OVX) of mice on the miRNA expression profile of their bones. METHODS: Micro-CT and histological analysis were performed on mice following OVX or sham-operation using the right mandibles. The left mandibles were used for microarray and quantitative RT-PCR to explore the change in their miRNA expression profile. The differentially expressed miRNAs (DEmiRs) of the OVX and sham-operated mice were analyzed by constructing the miRNA-mRNA-function complex network. We then also analyzed the different roles of the regulation of miRNAs in the mandible and femur by combining public data from GEO. RESULTS: OVX could lead to a significant decrease in the BMD in the mandible. A total of 53 DEmiRs including, 18 up-regulated and 35 down-regulated miRNAs, were identified. The analysis of the miRNA-mRNA-pathway complex network suggested that miR-17-5p and miRNA-297a-5p were potential biomarkers in the development of mandibles of OVX mice. A comparison of the analysis data on the mandible and femur showed that the transforming growth factor-ß signaling pathway was specifically regulated in the mandible, whereas the Wnt signaling pathway was specifically regulated in the femur. Moreover, miR-17-5p and miR-133a-3p showed different expression tendencies in the mandible and in the femur after OVX. CONCLUSION: This study provides an integrated function analysis of miRNA in mandibles after OVX and of miR-17-5p and miR-133a-3p as potential biomarkers. Moreover, the mechanism in mandibles may not be comparable with that in femurs with estrogen deficiency.