Effect and Possible Mechanism of Network Between MicroRNAs and RUNX2 Gene on Human Dental Follicle Cells

Abstract

To investigate whether crosstalk between RUNX2 and miRNAs is involved in tooth eruption regulated by dental follicle cells (DFCs) and the possible molecular mechanism. Blood samples and embedded dental follicles were collected from patients with cleidocranial dysplasia, and RUNX2 gene mutations were analyzed, then RUNX2(+/m) DFCs were isolated and identified. The characteristics of RUNX2(+/m) DFCs were analyzed. The differential expression of miRNAs was detected between the RUNX2(+/m) DFCs and RUNX2(+/+) DFCs by microarray, and target genes were predicted by miRGen. miR-146a was chosen for further investigation, and its effects in DFCs were analyzed by transfecting its mimics and inhibitors, and expression of genes involved in tooth eruption were detected. A novel insertion mutation (c.309_310insTG) of RUNX2 gene was identified which had an effect on the characteristics of DFCs. Compared with the RUNX2(+/+) DFCs, there were 69 microRNAs more than twofold up-regulated and 54 microRNAs more than twofold down-regulated in the RUNX2(+/m) DFCs. Among these, miR-146a decreased significantly in RUNX2(+/m) DFCs, and expression of RUNX2, CSF-1, EGFR, and OPG was significantly altered when miR-146a was overexpressed or inhibited. RUNX2 gene mutation contributes to the characteristic change of DFCs, and the crosstalk between RUNX2 gene and miRNAs may be one of the key regulatory mechanisms of differentiation of DFCs.

Puerarin promotes the viability and differentiation of MC3T3-E1 cells by miR-204-regulated Runx2 upregulation

“…The mechanism whether the other varied miRNAs among the miRNA expression profiles after puerarin treatment has effects on TGF-β1, Smad2 and Smad3 remains unknown. In fact, studies have indicated that Runx2, TGF-β1, Smad2 and Smad3 are capable of regulating the expression of miRNAs directly or indirectly (27)(28)(29), suggesting that regulatory factors and miRNAs are not independent and they regulate each other bidirectionally. In view of the promoting effect of puerarin on cellular viability and differentiation, its regulatory effects on miR-204 and the downstream target Runx2, the detailed upstream signaling pathway by which puerarin affects miR-204 downregulation is still unknown, which remains to be elucidated.…”

MicroRNA variants as genetic determinants of bone mass

“…In bone, Ets1 is also known to interact with CbfA1/Runx2, a quintessential transcription factor for osteogenesis [49]. In cells from a patient displaying Runx2 haploinsufficiency, levels of miR-146a were depressed, further suggesting a connection between Runx2 and miR-146a [50]. Although other SNPs in the promoter region of miR-146a have been recognized (rs17057381, rs73318382, and rs6864584), their function has not yet been ascertained.…”

Abnormal bone remodelling activity of dental follicle cells from a cleidocranial dysplasia patient

“…RUNX2 had been reported to be expressed in dental epithelium, dental papilla and dental follicles during tooth development and eruption (Camilleri & McDonald, ). In addition, RUNX 2 mutations would produce negative effects on expression of the RUNX2 protein in DFCs and periodontal ligament cells (PDLCs) of CCD patients (Chen et al., ; Li et al., ; Yoda, Suda, Kitahara, Komori, & Ohyama, ). However, the regulatory mechanism responsible for the delayed permanent tooth eruption mediated by DFCs in CCD patients has not been completely understood yet.…”