Effects of Choukroun's platelet-rich fibrin on human gingival fibroblasts proliferation, migration and type I collagen secretion / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of platelet-rich fibrin (PRF) on human gingival fibroblasts (HGF) biological behavior such as proliferation, migration and collagen-I expression.</p><p><b>METHODS</b>Human healthy gingival tissues were cultured according to the explant technique to obtain primary cultures. PRF was prepared by means of Choukroun's. HGF were co-cultured with PRF membrane originating from the same donor as the explants, divided into three groups, PRF1 group, PRF2 group and blank control group. Methyl thiazolyl tetrazolium (MTT) assay was used for cytotoxicity and cell proliferation study, and enzyme-linked immunosorbent assay (ELISA) for collagen-I (COL-I) secretion study at the 1st, 3rd, 5th day respectively. Eluates from PRF membrane was prepared, and divided into three groups, PRF1 group, PRF2 group and blank control group. Transwell chamber was utilized to determine the effect of PRF membrane eluate on cell migration.</p><p><b>RESULTS</b>The A values of HGF in culture of the PRF1 (0.615 ± 0.036, 0.686 ± 0.006, 0.693 ± 0.004) and PRF2 groups (0.653 ± 0.023, 0.766 ± 0.034, 0.775 ± 0.053) were significantly higher than those of the control cultures (0.514 ± 0.020, 0.544 ± 0.006, 0.545 ± 0.009) (P < 0.01), but the difference between PRF1 and PRF2 group was not significant (P > 0.05). In each group at different time points, the HGF proliferation effect was significantly enhanced with time (P < 0.01). Cell migration test showed that the migration numbers of HGF in PRF1 and PRF2 groups (85.67 ± 2.94, 85.83 ± 1.47) were significantly higher than those of the control group (54.17 ± 2.48) (P < 0.01), but the difference between the two experimental groups was not significant (P > 0.05). COL-I secretion test exhibited that the A values of COL-I in PRF1 (0.184 ± 0.004, 0.200 ± 0.004, 0.204 ± 0.009) and PRF2 group (0.213 ± 0.008, 0.226 ± 0.005, 0.229 ± 0.006) were significantly higher than the A values of the control group (0.174 ± 0.002, 0.184 ± 0.002, 0.186 ± 0.003) (P < 0.01), but the difference between the two experimental groups was not significant (P > 0.05). In each group, the secretion level of COL-I increased significantly with time (P < 0.01).</p><p><b>CONCLUSIONS</b>PRF could exert a positive effect on HGF biological behaviour and had clinical application potential in the treatment of gingival recession and in the periodontal tissue engineering when combined with seed cell HGF.</p>

Isolation and characterization of a DRE-binding transcription factor from Yinxin poplar (Populus alba x P. alba var. pyramidalis) / 生物工程学报

Dehydration-Responsive Element Binding ( DREB) transcription factors, specifically binding with dehydration reponsive element (DRE), activate a variety of stress-responsive genes in plants under abiotic stresses (dehydration, high salt and low temperature). Using PCR and homologous EST search, we isolated a DREB-like gene from Yinxin poplar (Populus alba x P. alba var. pyramidalis) named PaDREB2. Yeast One-hybrid experiment demonstrated that PaDREB2 protein could function as a DREB transcription factor activating target gene expression by specifically binding to DRE cis-element. To study the expression pattern of PaDREB2, RT-PCR was carried out. And the results showed that PaDREB2 is induced by low temperature, drought and high salt.