MicroRNA-27a-5p Downregulates Expression of Proinflammatory Cytokines in Lipopolysaccharide-Stimulated Human Dental Pulp Cells via the NF-κB Signaling Pathway.

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.

Biocompatibility and pro-mineralization effects of premixed calcium silicate-based materials on human dental pulp stem cells: An in vitro and in vivo study.

Premixed calcium silicate-based materials have recently been developed and are recommended for a wide range of endodontic procedures, including vital pulp therapy. This study investigated the in vitro biocompatibility and pro-mineralization effect and in vivo reparative dentin formation of EndoSequence Root Repair Material, EndoSequence BCRRM, Bio-C Repair, and Well-pulp PT. Both fresh and set extracts had no detrimental effect on the growth of human dental pulp stem cells.

Hypochlorous acid inactivates oral pathogens and a SARS-CoV-2-surrogate.

Background: Droplets and aerosols produced during dental procedures are a risk factor for microbial and viral transmission. Unlike sodium hypochlorite, hypochlorous acid (HOCl) is nontoxic to tissues but still exhibits broad microbicidal effect. HOCl solution may be applicable as a supplement to water and/or mouthwash.

Three-dimensional cellular visualization in mouse apical periodontitis using combined whole-mount staining and optical tissue clearing.

Apical periodontitis is an inflammatory disease involving lesions located within the jawbone. Histological evaluations generally require decalcification and sectioning, which has limited our understanding of the three-dimensional (3D) organization and spatial distribution of different immune cell types in these lesions. A recently developed technique combining tissue clearing and whole-mount immunofluorescent labeling allows us to acquire such information from the deep tissue without sectioning.

Kinetics of LYVE-1-positive M2-like macrophages in developing and repairing dental pulp in vivo and their pro-angiogenic activity in vitro.

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.

Hypoxia-inducible factor 1α induces osteo/odontoblast differentiation of human dental pulp stem cells via Wnt/β-catenin transcriptional cofactor BCL9.

Accelerated dental pulp mineralization is a common complication in avulsed/luxated teeth, although the mechanisms underlying this remain unclear. We hypothesized that hypoxia due to vascular severance may induce osteo/odontoblast differentiation of dental pulp stem cells (DPSCs). This study examined the role of B-cell CLL/lymphoma 9 (BCL9), which is downstream of hypoxia-inducible factor 1α (HIF1α) and a Wnt/β-catenin transcriptional cofactor, in the osteo/odontoblastic differentiation of human DPSCs (hDPSCs) under hypoxic conditions.

Revisiting the role of IL-1 signaling in the development of apical periodontitis.

Apical periodontitis (AP) develops as a result of an immune response to pulpal bacterial infection, and various cytokines are involved in the pathogenesis of AP, with Interleukin (IL)-1 being considered a key cytokine. The role of IL-1 in the pathogenesis of AP has been well studied. It is known that IL-1 expression in periapical lesions correlates closely with the development of AP.

Transient Receptor Potential Ankyrin 1 Is Up-Regulated in Response to Lipopolysaccharide via P38/Mitogen-Activated Protein Kinase in Dental Pulp Cells and Promotes Mineralization.

Increased expression of the transient receptor potential ankyrin 1 (TRPA1) channel has been detected in carious tooth pulp, suggesting involvement of TRPA1 in defense or repair of this tissue after exogenous noxious stimuli. This study aimed to elucidate the induction mechanism in response to lipopolysaccharide (LPS) stimulation and the function of TRPA1 in dental pulp cells. Stimulation of human dental pulp cells with LPS up-regulated TRPA1 expression, as demonstrated by quantitative RT-PCR and Western blotting.

Author Correction: Strontium ranelate promotes odonto-/osteogenic differentiation/mineralization of dental papillae cells in vitro and mineralized tissue formation of the dental pulp in vivo.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

HIF1α inhibits LPS-mediated induction of IL-6 synthesis via SOCS3-dependent CEBPβ suppression in human dental pulp cells.

Hypoxia-inducible factor 1 alpha (HIF1α) is a transcriptional factor that plays a key role in the regulation of various molecules expressed in hypoxic conditions. Ischemic/hypoxic conditions are regarded as a distinct characteristic of dental pulp inflammation due to the encasement of pulp tissue within the rigid tooth structure. This study was performed to examine the role of HIF1α in the regulation of interleukin (IL)-6, a proinflammatory cytokine expressed in inflamed dental pulp, in lipopolysaccharide (LPS)-stimulated human dental pulp cells (hDPCs).

Anti-inflammatory roles of microRNA 21 in lipopolysaccharide-stimulated human dental pulp cells.

microRNAs are small noncoding RNA molecules that regulate RNA silencing and posttranscriptional gene expression, and many microRNAs are involved in inflammatory processes. In particular, microRNA 21 (miR-21) is upregulated in inflammatory environment and reported to induce anti-inflammatory responses. However, the involvement of miR-21 in pulpal inflammation and the precise mechanisms of anti-inflammatory reactions induced by miR-21 remain unclear.

Strontium ranelate promotes odonto-/osteogenic differentiation/mineralization of dental papillae cells in vitro and mineralized tissue formation of the dental pulp in vivo.

This study examined the effects and mechanisms of strontium ranelate (SrRn)-a drug used to treat osteoporosis-on the proliferation and differentiation/mineralization of cloned dental pulp-like cells (mouse dental papillae cells; MDPs). It also determined whether topical application of SrRn to exposed dental pulp tissue promotes the formation of mineralized tissue in vivo. The MDPs were cultured with or without SrRn, and cell proliferation, odonto-/osteoblastic gene expression, mineralized nodule formation, and Akt phosphorylation were evaluated.

Transient receptor potential melastatin (TRPM) 8 is expressed in freshly isolated native human odontoblasts.

Objective: Cold-sensitive ion channels, such as transient receptor potential melastatin (TRPM) 8 and transient receptor potential ankyrin (TRPA) 1, may play a crucial role in the nociceptive function of odontoblasts, whereas expression of these TRP channels in human native odontoblasts remains to be elucidated. This study aimed to analyze the expression of TRPM8 and TRPA1 in freshly isolated native human odontoblasts.

Design: Odontoblasts were isolated from freshly extracted healthy human teeth (n=4); after removing the inner pulp tissues from the pulp chambers, odontoblasts remaining on the dentin surface were washed out with phosphate buffered saline and collected.