To investigate the effect of miR-214 on the osteogenic differentiation of dental follicle cells (DFCs).

Purified DFCs were cultured in vitro by bidirectional differential passage, with the untransfected DFCs as the control group (DFCs group). The expression of miR-214-3p in DFCs was upregulated and downregulated by transfection of miR-214-3p(miR-214 mimics group) or miR-214-3p inhibitors(miR-214 inhibitor group) into DFCs. The expression levels of miR-214, alkaline phosphatase (ALP), osteonectin (OSN) and runt-related transcription factor-2 (RUNX-2) were detected by qRT-PCR after 7 days of osteogenesis induction, the protein expression levels of RUNX-2 and β-catenin were detected by western blot, and the formation of mineralized nodules was observed with alizarin red staining after 14 days of osteogenesis induction.

Compared with the DFCs group, in the miR-214 mimics group, the expression of miR-214 was upregulated after 7 days of osteogenesis induction. The mRNA expression of ALP, OSN and RUNX-2 in the miR-214 mimics group was lower than that in the DFCs group, but only ALP in the two groups was statistically significant (P > 0.05); the mRNA expression of ALP, OSN and RUNX-2 in the miR-214 inhibitor group was higher than that in the DFCs group, and the difference was statistically significant (P < 0.05). The protein expression of RUNX-2 and β-catenin in the miR-214 mimics group was lower than that in the miR-214 inhibitor group. The number of calcified nodules in the miR-214 mimics group was significantly less than that in the DFCs group, while that in the miR-214 inhibitor group was significantly higher than that in the DFCs group.

The upregulation of miR-214 can downregulate the expression of β-catenin, can inhibit the expression of ALP, OSN and RUNX-2 related to osteogenesis, and can inhibit osteogenic differentiation. The downregulation of miR-214 demonstrated the opposite results; miR-214 may downregulate the expression of β-catenin and inhibit the osteogenic differentiation of DFCs.

The serum levels of iron, zinc, copper and vitamin D in severe early childhood caries (S-ECC) patients were investigated and analyzed to provide reference for primary prevention and diagnosis of S-ECC children.

A total of 184 children were enrolled in the Children Health Department of Xinjiang Medical University Health Management Center from June 2018 to June 2019. They were divided into the caries-free (CF) group (n＝89) and S-ECC group (n＝95). The contents of iron, zinc, copper and vitamin D were detected.

The serum iron content of the CF group and S-ECC group was (8.36 ± 0.42) mmol/L and (8.13 ± 0.44) mmol/L, respectively, and the difference was statistically significant (t＝3.50, P < 0.001); the serum content of zinc was (83.18 ± 7.28) μmol/L and (79.23 ± 6.38) μmol/L, respectively, and the difference was statistically significant (t＝3.92, P < 0.001); the serum content of 25-hydroxyvitamin D was (86.72 ± 15.83) nmol/L and (77.75 ± 11.38) nmol/L, respectively, and the difference was statistically significant (t＝4.42, P < 0.001). The serum copper content of CF group and S-ECC group was (20.18 ± 4.84) μmol/L and (19.49 ± 4.62) μmol/L, but the difference was not statistically significant (t＝0.97, P＝0.33).

The contents of iron, zinc and vitamin D in the serum of S-ECC patients are low, suggesting that iron, zinc and vitamin D supplementation should be emphasized in the prevention and treatment of S-ECC.

Systematic evaluation of the correlation of HLA-DQB1 and HLA-DRB1 allele polymorphisms with caries, to provide reference for caries prevention and treatment.

Relevant literature published before December 2020 was searched in the Cochrane Library, PubMed, Embase, Web of Science, Scopus, CNKI, Wanfang, VIP, and CBM databases. Meta-analysis was performed using the R4.0.2 software to test for heterogeneity and evaluate the publication bias.

In total,10 case-control studies were included with 564 people in the case group and 676 people in the control group. The results of the Meta-analysis show that: ① HLA-DQB1*02 (OR＝0.52, 95%CI＝0.29-0.93, P < 0.05) and HLA-DRB1*09 (OR＝0.34, 95%CI＝0.21-0.58, P < 0.05) are protective factors of dental caries; ② HLA-DRB1*13 (OR＝2.96, 95%CI＝2.03-4.33, P < 0.05) and HLA-DRB1*14 (OR＝1.95, 95%CI＝1.26- 3.02, P < 0.05) alleles are risk factors for the development of dental caries. The results of the subgroup analysis are: HLA-DRB1*07 is a caries susceptibility factor in the Chinese population (OR＝0.48, 95% CI＝0.24-0.97, P < 0.05), while it is not statistically significant in the Brazilian and Turkish populations; HLA-DRB1*11 is a caries protective factor in the saliva group (OR＝2.26, 95% CI＝1.46-3.52, P < 0.05). 3.52, P < 0.001), while it is a caries susceptibility factor in the blood group (OR＝0.09, 95% CI＝0.12-0.34, P < 0.001).

HLA-DRB1*13 and HLA-DRB1* 14 alleles are caries susceptibility genes, and HLA-DQB1*02 and HLA-DRB1*09 have protective effects on the caries development. HLA-DRB1*07 is a caries susceptibility gene in the Chinese population; HLA-DRB1*11 is a caries protective gene in the saliva group. Due to the limited sample size and quality of the included studies, more high-quality studies will be included later for verification.

To develop a simple and fast purifingmethod of dental follicle cell by the character of different velocity of attachment of detachment between dental follicle cells and enamel organ cells.

The lower first intact molar germs of SD rats with 5-6 days old were selected and separated. The dental follicle and enamel organ were stipped together under the stereo microscope. After minced into little pieces and degested with trypsin and cultured, the dental follicle cells were purified by diffierential adherence and differential passage. The final purified cells were identified by immunocytochemistry.

The primay cells were mixed, consisting of dental follice cells and enamel organ cells. After differential adherence and passage, the cells of 2-3th passage became purified dental follicle cells. Purified dental follicle cells were elongate spindle or triangle in shape, positive for vimentin and negative for cytokeratin.

Bidirectional differential method is an efficient and simple method for the purification of dental follicle cells.