2020 Fiscal Year Research-status Report
APPLICATION OF RvD2 AS A REGENERATIVE DIRECT PULP CAPPING MATERIAL
Project/Area Number |
20K09938
|
Research Institution | Okayama University |
Principal Investigator |
|
Co-Investigator(Kenkyū-buntansha) |
大森 一弘 岡山大学, 大学病院, 講師 (20549860)
山城 圭介 岡山大学, 大学病院, 講師 (30581087) [Withdrawn]
高柴 正悟 岡山大学, 医歯薬学総合研究科, 教授 (50226768)
|
Project Period (FY) |
2020-04-01 – 2023-03-31
|
Keywords | Vital pulp therapy / Resolvin D2 (RVD2) / Dentin regeneration |
Outline of Annual Research Achievements |
Vital pulp therapy (VPT)’s goal is to stimulate dentin regeneration after pulp injury. The known VPT materials have issues about operability and biocompatibility. Because the best replacement tissue is the one produced by a self-defense mechanism, we target resolvin D2 (RVD2), an anti-inflammatory lipid mediator that acts at the resolution stage of inflammation. RVD2 is produced by macrophages, endothelial cells, and dental pulp stem cells. We reported that RVD2 resolves apical periodontitis promoting healing of the periapical bone lesion. RVD2 also has analgesic, angiogenesis, and bacterial clearance effects. Thus, our hypothesis is that RVD2 being a cell-produced bioactive molecule will fulfill the expectations of the “ideal” VPT material. The aim of this study in this year is to evaluate RVD2 as a VPT material. A pulpotomy in vivo model was applied using SD 8 weeks old rats. After removing coronal pulp, 4 different reagents RDV2 (1 and 10 ng/ul), PBS and Ca (OH)2 were applied into the root’s pulp. 2, 4 and 6 weeks later simple CT, micro-CT images, histological and immunohistochemistry analysis were done. Calcified tissue was observed on simple CT and micro-CT images in RVD2 and CA(OH)2 groups. H&E and Masson trichrome staining confirmed the presence of dentin regeneration in those groups. No apical periodontitis was observed in any group. Immunohistochemistry revealed the presence of GPR18 in RVD2 groups. RVD2 may promote calcified tissue formation in VPT by stimulating dentin regeneration. We need to clarify a possibility that RVD2 would be a new candidate for VPT.
|
Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
The following goals have been achieved. In vivo experiments, 1) the pulpotomy rat model has been standardized, 2) the dentin bridge regeneration at the pulp injury after RVD2 application as a VPT agent has been found, 3) immunohistochemistry confirmed the presence of GPR18 on RVD2 groups. In vitro experiments, due to some technical troubles during the performance of quantitative real-time PCR analysis, we are behind the schedule, so we are currently developing this assay.
|
Strategy for Future Research Activity |
In vitro experiments, to examine the effects of RVD2 on dental pulp cells we will perform real-time PCR to evaluate the expression of the following markers: anti-inflammatory effect (IFN-γ, IL-10, IL-17, TGF-β), live inflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α), angiogenesis and tissue regeneration action (VEGF), hard tissue formation (wnt3a, wnt10a, β-catenin), analgesic effect (TRPA1, substance P), dentin related markers (DSPP, DMP-1, alkaline phosphatase, osteocalcin), RvD2 receptor (GPR18). In vivo experiments, IVIS-analysis for the detection of MPO activity
|
Causes of Carryover |
Because of the expansion of COVID-19, there were no travel expenses. If the COVID-19 pandemic continues we are planning to use the travel expenses for the next physical year on articles required for the experiments.
|