Functional exploration of SNP mutations in HIF2αb gene correlated with hypoxia tolerance in blunt snout bream (Megalobrama amblycephala).

Blunt snout bream (Megalobrama amblycephala) is sensitive to hypoxia environment. Hypoxia-inducible factor (HIF) is the most critical factor in the HIF pathway, which strictly regulates the hypoxia stress process of fish. In this study, we found six hifα genes in blunt snout bream that demonstrated different expressions under hypoxia conditions. In HEK293T cells, all six hifαs were detected to activate the HRE region by luciferase reporter assay. More importantly, we identified two linkage-disequilibrium SNP sites at exon 203 and 752 of the hif2αb gene in blunt snout bream. Haplotype II (A203A752) and its homozygous diplotype II (A203A203A752A752) appeared frequently in a selected strain of blunt snout bream with hypoxia tolerance. Diplotype II has a lower oxygen tension threshold for loss of equilibrium (LOEcrit) over a similar range of temperatures. Moreover, its erythrocyte number increased significantly (p < 0.05) than those in diplotype I and diplotype III strains at 48 h of hypoxia. The enzymes related with hypoxia tolerant traits, i.e., reduced glutathione, superoxide dismutase, and catalase, were also significantly (p < 0.05) induced in diplotype II than in diplotype I or III. In addition, the expression of epo in the liver of diplotype II was significantly (p < 0.01) higher than that in the diplotype I or III strains at 48 h of hypoxia. Taken together, our results found that the hypoxia-tolerant-related diplotype II of hif2αb has the potential to be used as a molecular marker in future genetic breeding of hypoxia-tolerant strain.

The Effect of Nonaugmentative Approaches in the Surgical Treatment of Peri-implantitis: A Systematic Review and Network Meta-analysis.

PURPOSE: This systematic review and Bayesian network meta-analysis (NMA) were performed to compare the clinical effects of nonaugmentative adjunctive approaches in the surgical treatment of peri-implantitis. MATERIALS AND METHODS: A systematic search of six electronic databases was performed up to June 20, 2020. Additional relevant literature was identified through gray literature and hand searches. Randomized controlled trials (RCTs) of surgical treatment of periimplantitis with nonaugmentative adjunctive approaches were included. Probing depth (PD) changes, marginal bone level (MBL) changes, and treatment success rates were extracted and assessed. Pairwise meta-analysis and Bayesian NMA were performed. This review was registered at PROSPERO (CRD42020191113). RESULTS: The search yielded 7,419 articles, of which 10 studies with 11 articles were included in the quantitative analysis. In the NMA of mechanical approaches and photodynamic therapy (PDT), compared with hand curettes, implantoplasty provided significant additional PD improvement at the 6-month follow-up evaluation (mean difference [MD]: 1.29; 95% confidence interval [CI]: 0.17, 2.38) and 12-month follow-up evaluation (MD: 1.39; 95% CI: 0.91, 1.74). In the NMA of antiseptics and systemic antibiotics, adjunctive use of antiseptics and/or systemic antibiotics did not provide significant improvement in PD or MBL. In the NMA of all adjunctive approaches, no significant differences were found in PD improvements. CONCLUSION: Within the limitations of this systematic review and NMA, implantoplasty is more effective than hand curettes in improving PD in the surgical treatment of peri-implantitis. Chemical antiseptics or systemic antibiotics have a limited effect on improving PD and MBL.

Comprehensive Transcriptome Analysis of mRNA Expression Patterns Associated With Enhanced Biological Functions in Periodontal Ligament Stem Cells Subjected to Short-Term Hypoxia Pretreatment.

Short-term hypoxia pretreatment significantly enhances periodontal ligament stem cell (PDLSC)-based periodontal tissue regeneration by improving various cellular biological functions, but the underlying mechanisms remain unclear. In this study, based on RNA sequencing (RNA-seq), we comprehensively analyzed the possible regulatory mechanisms of the short-term hypoxic effects on the biological functions of healthy and inflammatory PDLSCs. A total of 134 and 164 differentially expressed genes (DEGs) were identified under healthy and inflammatory conditions, respectively. Functional enrichment analyses indicated that DEGs under both conditions share certain biological processes and pathways, including metabolic processes, developmental processes, reproductive processes, localization, immune system processes and the HIF-1 signaling pathway. The DEGs identified under inflammatory conditions were more significantly enriched in cell cycle-related processes and immune-related pathways, while DEGs identified under healthy condition were more significantly enriched in the TGF-ß signaling pathway. A protein-protein interaction network analysis of the 59 DEGs in both conditions was performed, and 15 hub genes were identified. These hub genes were mainly involved in glycolysis, the cellular response to hypoxia, cell differentiation, and immune system processes. In addition, we found that hypoxia induced significant differential expression of genes associated with proliferation, differentiation, migration, apoptosis and immunoregulation under both healthy and inflammatory conditions. This study provides comprehensive insights into the effects of short-term hypoxia on the biological functions of PDLSCs and suggests a potentially feasible strategy for improving the clinical effectiveness of cell-based periodontal tissue engineering.