Search

MicroRNA-27a-5p (miR-27a-5p) was significantly upregulated in dental pulp inflammation, yet its underlying mechanisms remain unclear. This study investigated the effect of miR-27a-5p on the expression of proinflammatory cytokines in human dental pulp cells (hDPCs) stimulated by lipopolysaccharide (LPS). LPS-stimulated hDPCs showed concurrent increases in the expression of miR-27a-5p and proinflammatory cytokines (IL-6, IL-8, and MCP1), and the increased expression was suppressed by NF-κB inhibitor BAY 11-0785. Transfection of the miR-27a-5p mimic downregulated the expression of proinflammatory cytokines, NF-κB activity, and the expression of NF-κB signaling activators (TAB1, IRAK4, RELA, and FSTL1) in LPS-stimulated hDPCs. Luciferase reporter assays revealed that miR-27a-5p bound directly to the 3'-UTR of TAB1. siTAB1 downregulated NF-κB activity and proinflammatory cytokine expression. Downregulation of proinflammatory cytokine expression, NF-κB activity, and NF-κB signaling activator expression (TAB1, IRAK4, and RELA) was also found in LPS-stimulated rat incisor pulp tissue explants following transfection with the miR-27a-5p mimic ex vivo. MiR-27a-5p, whose expression was induced by NF-κB signaling, negatively regulated the synthesis of proinflammatory cytokines via targeting NF-κB signaling. In particular, TAB1, a potent NF-κB activator, was targeted by miR-27a-5p. These results provide insights into the negative regulatory effects of miR-27a-5p, particularly those targeting the TAB1-NF-κB signaling pathway, on pulp inflammation.

MicroRNA-146b-5p (miR-146b-5p) is up-regulated during and to suppress the inflammation process, although mechanisms involved in the action of miR-146b-5p have not been fully elucidated. This study examined the anti-inflammation effects of miR-146b-5p in lipopolysaccharide (LPS)-stimulated human dental pulp cells (hDPCs). An increase in human miR-146b-5p (hsa-miR-146b-5p) expression following the mRNA expression of pro-inflammatory cytokines was observed in LPS-stimulated hDPCs. The expression of hsa-miR-146b-5p and pro-inflammatory cytokines was down-regulated by a nuclear factor-kappa B (NF-κB) inhibitor, and the expression of hsa-miR-146b-5p was also decreased by a JAK1/2 inhibitor. Enforced expression of hsa-miR-146b-5p abolished phosphorylation of NF-κB p65 and down-regulated the expression of pro-inflammatory cytokines and NF-κB signaling components, such as interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), and REL-associated protein involved in NF-κB (RELA). Expression of rat miR-146b-5p (rno-miR-146b-5p) and pro-inflammatory cytokine mRNA was also up-regulated in experimentally-induced rat pulpal inflammation in vivo, and rno-miR-146b-5p blocked the mRNA expression of pro-inflammatory mediators and NF-κB signaling components in LPS-stimulated ex vivo cultured rat incisor pulp tissues. These findings suggest that the synthesis of miR-146b-5p is controlled via an NF-κB/IL6/STAT3 signaling cascade, and in turn, miR-146b-5p down-regulates the expression of pro-inflammatory mediators by targeting TRAF6, IRAK1, and RELA in LPS-stimulated hDPCs.

Tissue-resident macrophages expressing lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) are found in multiple tissues and organs. We aimed to evaluate the dynamics and biological functions of LYVE-1 + macrophages in dental pulp during post-injury tissue remodeling. Immunofluorescence staining of mouse embryos revealed that LYVE-1 + macrophages colonized dental pulp before birth. In mature rat molar dental pulp, LYVE-1 + macrophages were the main subset of macrophages expressing CD163, an M2 marker, and were distributed throughout the tissue. In response to dental pulp injury induced by cavity preparation, LYVE-1 + macrophages quickly disappeared from the affected area of the pulp and gradually repopulated during the wound healing process. RAW264.7 mouse macrophages cultured with a mixture of macrophage colony-stimulating factor, interleukin-4, and dexamethasone increased LYVE-1 expression, whereas lipopolysaccharide-stimulation decreased LYVE-1 expression. Enforced expression of Lyve1 in RAW264.7 cells resulted in increased mRNA expression of matrix metalloproteinase 2 (Mmp2), Mmp9, and vascular endothelial growth factor A (Vegfa). Lyve1-expressing macrophages promoted the migration and tube formation of human umbilical vein endothelial cells. In conclusion, LYVE-1 + tissue-resident M2-like macrophages in dental pulp showed dynamism in response to pulp injury, and possibly play an important role in angiogenesis during wound healing and tissue remodeling., (© 2022. The Author(s).)

Aim: The aim of the present study was to assess the association of periodontitis with dental and smoking behaviors, self-perception of oral status, dental knowledge, and obesity in Vietnamese patients., Methods: A cross-sectional study was conducted on 367 adults who first visited the Faculty of Odonto-Stomatology, University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam. Information on demographic characteristics, dental and smoking behaviors, self-perception of oral status, dental knowledge, and nutritional status was investigated by a self-administered questionnaire. Periodontal status, including plaque index, probing depth, and bleeding on probing, was examined. Multiple logistic regression analysis was performed to explore risk factors that were associated with periodontitis after adjusting for confounding factors., Results: Dental and smoking behaviors, dental knowledge, and nutritional status were all significantly related to periodontitis. The multiple logistic regression analysis showed that patients who had risk factors significantly associated with periodontitis were those who had dental scaling during the past year (odds ratio [OR]: 2.2), current smokers (OR: 2.47), who received instructions on oral hygiene (OR=1.73), and those who were overweight/obese (OR: 4.78)., Conclusion: Periodontitis was correlated with dental and smoking behaviors, dental knowledge, and nutritional status in Vietnamese dental patients. Promoting a healthy lifestyle, reducing tobacco consumption, motivating oral self-care behaviors, together with normal weight maintenance, are necessary to reduce periodontal disease burdens., (© 2017 John Wiley & Sons Australia, Ltd.)

Biological treatment with sulfate-reducing bacteria (SRB) is considered to be an excellent option to remove heavy metals from wastewater. In this study, the optimization of sulfide production for an enhanced removal of lead by a consortium of SRB was carried out based on central composite design and analyzed using response surface methodology (RSM). The sulfide production process was investigated as a function of three independent variables: solution pH (6.5-8.5), lactate concentration (32-96 mM), and sulfate concentration (16-32 mM). RSM analysis showed that the optimum conditions for a high sulfide concentration (14.2 mM) occurred at a pH of 7.5 and at lactate and sulfate concentrations of 53.4 mM and 22.6 mM, respectively. The lead removal efficiency of the SRB consortium using optimum conditions was determined in four parallel anaerobic continuous moving bed biofilm reactors (V = 2 L) that were fed with synthetic wastewater containing dissolved lead at concentrations of 0, 100, 150, 200 mg L(-1) and operated with a hydraulic retention time of 5 days. 99-100 % was removed from synthetic wastewater with lead concentrations of 100 and 150 mg L(-1) during 40 days of operation. For the highest lead concentration of 200 mg L(-1), a decrease in efficiency of removal (96 %) was observed at the end of the experiment.