Katsuhiro Mieda, Tadashi Nakanishi, Hitomi Kuramoto, Yoshitaka Hosokawa, Ikuko Hosokawa, Daisuke Takegawa and Keiichi Hosaka : Sudachitin reduces inflammatory mediator expression in toll-like receptor 2 ligand-stimulated human dental pulp cells, Cell Biochemistry and Biophysics, 83, 2, 2431-2439, 2025.
(要約)
Sudachitin, which is a polymethoxy flavonoid derived from the peer of Citrus sudachi, has several biological properties. However, the effect of sudachitin on human dental pulp cells (HDPCs) remains unclear. The aim of this study was to investigate whether sudachitin could decrease the expression of inflammatory mediators such as cytokines and prostaglandin in HDPCs stimulated with Pam3CSK4, a ligand for toll-like receptor (TLR) 2. HDPCs were pre-incubated with different concentrations of sudachitin (6.25, 12.5, 25, or 50 μM) and stimulated with Pam3CSK4 (100 ng/mL). The quantification of inflammatory cytokines (interleukin (IL)-6, IL-8, and C-X-C motif chemokine ligand (CXCL) 10) and prostaglandin E (PGE) were performed by enzyme-linked immunosorbent assay (ELISA). The expression of cyclooxygenase (COX)-2, a key enzyme for PGE formation, was analyzed by western blot. Moreover, the activations of cell signal pathways were examined by western blot analysis. Sudachitin suppressed IL-6, IL-8, CXCL10, and PGE production and COX-2 protein expression in Pam3CSK4-stimulated HDPCs. In addition, we revealed that nuclear factor-kappa B (NF-κB) and protein kinase B (Akt) pathways in the Pam3CSK4-stimulated HDPCs were inhibited by sudachitin treatment. These findings suggest that sudachitin can reduce inflammatory mediator production in HDPCs stimulated with TLR2 ligand by inhibiting NF-κB and Akt activations.
Daisuke Takegawa, Yoshihito Naitou, Kohichi Kani, Takaaki Tsunematsu, Hitomi Kuramoto and Tadashi Nakanishi : Severe Root Resorption with Pulp Fibrosis Despite Normal Responses to Pulp Sensibility Tests: A Case Report, Operative Dentistry, Endodontology and Periodontology, 5, 1, 70-76, 2025.
(要約)
<p> Purpose: We report a rare case of atypical external root resorption in the mid-root region of a mandibular molar following direct pulp capping (DPC), despite the tooth consistently exhibiting normal responses to pulp sensibility tests. We discuss the diagnostic challenges presented by such cases, focusing on the limitations of conventional pulp testing, the potential role of pathological pulp fibrosis, and the importance of cone-beam computed tomography (CBCT) in early detection and accurate diagnosis.</p><p> Case: A 38-year-old male patient presented with a chief complaint of chronic discomfort and distal gingival swelling in the right mandibular second molar. The tooth had undergone DPC with calcium hydroxide nine years earlier due to pulp exposure following complete caries removal. Clinical examination revealed mild gingival swelling and slight tenderness to percussion, with normal periodontal probing depths. The electric pulp test (EPT) and cold test showed normal responses, which were consistent with the results from a previous visit six years earlier. A dental radiograph taken six years earlier showed no abnormalities; however, comparison with the radiograph obtained at presentation revealed extensive external root resorption localized to the mid-root area of the mesial root. CBCT images confirmed that the resorption had perforated the dentin and reached the pulp chamber, accompanied by substantial loss of lingual alveolar bone. The prognosis was ultimately deemed poor, and the tooth was extracted. The extracted tissue was subjected to histopathological examination using hematoxylin and eosin staining. Histopathological analysis revealed extensive fibrosis in the pulp tissue without bacterial infection. In addition, chronic inflammatory granulation tissue, mainly with neutrophil infiltration, was observed in the area of external root resorption.</p><p> Discussion: This case highlights the limitations of relying solely on pulp sensibility tests for assessing pulp health. Especially in teeth with a history of DPC and chronic symptoms, underlying pathological changes, such as fibrosis, may not alter nerve responses until later stages. Atypical external root resorption can occur secondary to these changes, potentially progressing significantly without typical symptoms or radiographic signs on conventional 2D imaging. CBCT proved useful for identifying the precise location, extent, and perforation of the resorption lesion, underscoring its value in diagnosing complex endodontic-periodontal conditions.</p><p> Conclusion: Early use of CBCT should be considered in teeth with persistent symptoms after DPC, even in patients with normal pulp sensibility tests results, to facilitate timely diagnosis and appropriate management.</p>
(キーワード)
root resorption / electric pulp test (EPT) / cone-beam computed tomography (CBCT)
Tadashi Nakanishi, Katsuhiro Mieda, Hitomi Kuramoto and Daisuke Takegawa : Effect of interleukin-17A on inflammatory mediator production in interleukin-1β-stimulated human dental pulp fibroblasts, European Journal of Oral Sciences, 132, 5, e13019, 2024.
(要約)
In response to pro-inflammatory cytokines such as interleukin (IL)-1β, dental pulp fibroblasts produce various inflammatory mediators, including IL-6, IL-8, CC chemokine ligand 20 (CCL20), and CXC chemokine ligand 10 (CXCL10), leading to the progression of pulpitis. IL-17/IL-17A (IL-17A) is a pro-inflammatory cytokine secreted by T helper (Th) 17 cells following their recruitment to inflamed sites; however, the roles of IL-17A during pulpitis remain unclear. The purpose of this study was to investigate the effect of IL-17A on IL-6, IL-8, CCL20 and CXCL10 production by human dental pulp fibroblasts (HDPFs) in vitro. IL-17A at a concentration of 100 ng/ml induced the production of 10 times more IL-8 and 4 times more CXCL10, but not IL-6 and CCL20, compared to controls. Co-stimulation of HDPFs with IL-17A and IL-1β synergistically enhanced the production of IL-6, CCL20, IL-8 and CXCL10. IL-1β increased expression of IL-17 receptor/IL-17RA (IL-17R) on HDPFs. Moreover, the cell signal pathways of p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) were more potently activated by simultaneous stimulation with IL-17A and IL-1β. These findings suggest that IL-17A participates in the progression of dental pulp inflammation through the enhanced production of inflammatory mediators in HDPFs.
Yoko Asahi, Katsuaki Naito, Hikaru Kanda, Kazuaki Niwano, Daisuke Takegawa, Hiromichi Yumoto, Yoichiro Noiri and Mikako Hayashi : Clinical investigation of the inhibitory effects of tooth-coating materials on initial active root caries: a pilot randomized controlled trial, Medicina, 60, 1, 150, 2024.
(要約)
: Caredyne ZIF-C is a novel, capsule-mixed zinc-containing prototype glass ionomer cement (GIC). Zinc ions are reported to inhibit root dentin demineralization, dentin collagen degradation, bacterial growth, acid production, and in vitro bacterial biofilm formation. However, the effectiveness of GICs against initial root caries lesions is unclear. Therefore, this study aimed to evaluate the efficacy of GICs, especially the new zinc-containing Caredyne ZIF-C GIC, as tooth-coating materials in patients with initial active root caries. : A total of 58 lesions in 47 older adults (age > 65 years) were randomly allocated to one of the following three groups: Caredyne ZIF-C, Fuji VII (a conventional GIC), and sodium fluoride (NaF). All the lesions were treated with the assigned materials without removing the infected dentin, and the rates of dental plaque attachment and coating material fall-out were evaluated after 3, 6, and 12 months. The failure rate was defined as the number of teeth that needed restoration due to caries progression. : The plaque attachment rates tended to be lower in the material-coated root surfaces than in the healthy exposed root surfaces after 3, 6, and 12 months, although the differences among the three groups were not significant. Moreover, the coating material fall-out rate tended to be lower in the Caredyne ZIF-C group than in the Fuji VII group. There was no significant difference in the failure rate among the three groups at the 12 months mark. : Though this pilot study offers a new direction for suppressing the progression of initial active root caries by controlling plaque attachment using GICs including Caredyne ZIF-C, clinical studies with a larger sample size are needed.
(キーワード)
Humans / Aged / Root Caries / Pilot Projects / Dental Caries / Health Status / Zinc
Hitomi Kuramoto, Tadashi Nakanishi, Daisuke Takegawa, MIEDA Katsuhiro and Keiichi Hosaka : Caffeic Acid Phenethyl Ester Induces Vascular Endothelial Growth Factor Production and Inhibits CXCL10 Production in Human Dental Pulp Cells, Current Issues in Molecular Biology, 44, 11, 5691-5699, 2022.
(要約)
The survival rate of root non-vital teeth is lower than that of vital teeth. Therefore, to preserve the dental pulp is very important. The vascular endothelial growth factor (VEGF) is the most potent angiogenic factor involved in the vitality of dental pulp including reparative dentin formation. Caffeic acid phenethyl ester (CAPE) is a physiologically active substance of propolis and has some bioactivities such as anti-inflammatory effects. However, there are no reports on the effects of CAPE on dental pulp inflammation. In this study, we investigated the effects of CAPE on VEGF and inflammatory cytokine production in human dental pulp cells (HDPCs) to apply CAPE to an ideal dental pulp protective agent. We found that CAPE induced VEGF production from HDPCs. Moreover, CAPE induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases (ERK), and stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) in HDPCs. Furthermore, CAPE inhibited C-X-C motif chemokine ligand 10 (CXCL10) production in Pam3CSK4- and tumor necrosis factor-alpha (TNF-α)-stimulated HDPCs. In conclusion, these results suggest that CAPE might be useful as a novel biological material for vital pulp therapy by exerting the effects of VEGF production and anti-inflammatory activities.
Hitomi Kuramoto, Kouji Hirao, Hiromichi Yumoto, Yuki Hosokawa, Tadashi Nakanishi, Daisuke Takegawa, Ayako Washio, Chiaki Kitamura and Takashi Matsuo : Caffeic acid phenethyl ester (CAPE) induces VEGF expression and production in rat odontoblastic cells, BioMed Research International, Article ID 5390720, 2019.
(要約)
Caffeic acid phenethyl ester (CAPE), the main component of propolis, has various biological activities including anti-inflammatory effect and wound healing promotion. Odontoblasts located in the outermost layer of dental pulp play crucial roles such as production of growth factors and formation of hard tissue termed reparative dentin in host defense against dental caries. In this study, we investigated the effects of CAPE on the upregulation of vascular endothelial growth factor (VEGF) and calcification activities of odontoblasts, leading to development of novel therapy for dental pulp inflammation caused by dental caries. CAPE significantly induced mRNA expression and production of VEGF in rat clonal odontoblast-like KN-3 cells cultured in normal medium or osteogenic induction medium. CAPE treatment enhanced nuclear factor-kappa B (NF-B) transcription factor activation, and furthermore, the specific inhibitor of NF-B significantly reduced VEGF production. The expression of VEGF receptor- (VEGFR-) 2, not VEGFR-1, was up regulated in KN-3 cells treated with CAPE. In addition, VEGF significantly increased mineralization activity in KN-3 cells. These findings suggest that CAPE might be useful as a novel biological material for the dental pulp conservative therapy.
Yuki Hosokawa, Kouji Hirao, Hiromichi Yumoto, Ayako Washio, Tadashi Nakanishi, Daisuke Takegawa, Chiaki Kitamura and Takashi Matsuo : Functional roles of NOD1 in odontoblasts on dental pulp innate immunity, BioMed Research International, 2016, 9325436, 2016.
(要約)
Caries-related pathogens are first recognized by odontoblasts and induce inflammatory events that develop to pulpitis. Generally, initial sensing of microbial pathogens is mediated by pattern recognition receptors, such as Toll-like receptor and nucleotide-binding oligomerization domain (NOD); however, little is known about NODs in odontoblasts. In this study, the levels of NODs expressed in rat odontoblastic cell line, KN-3, were assessed by flow cytometry and the levels of chemokines in NOD-specific ligand-stimulated KN-3 cells were analyzed by real-time PCR and ELISA. The signal transduction pathway activated with NOD-specific ligand was assessed by blocking assay with specific inhibitors and reporter assay. In KN-3 cells, the expression level of NOD1 was stronger than that of NOD2 and the production of chemokines, such as CINC-1, CINC-2, CCL20, and MCP-1, was upregulated by stimulation with NOD1-specific ligand, but not with NOD2-specific ligand. CINC-2 and CCL20 production by stimulation with NOD1-specific ligand was reduced by p38 MAPK and AP-1 signaling inhibitors. Furthermore, the reporter assay demonstrated AP-1 activation in NOD1-specific ligand-stimulated KN-3 cells. These findings indicated that NOD1 expressed in odontoblasts functions to upregulate the chemokines expression via p38-AP-1 signaling pathway and suggested that NOD1 may play important roles in the initiation and progression of pulpitis.
Tadashi Nakanishi, Kayo Mukai, Yoshitaka Hosokawa, Daisuke Takegawa and Takashi Matsuo : Catechins inhibit vascular endothelial growth factor production and cyclooxygenase-2 expression in human dental pulp cells, International Endodontic Journal, 48, 3, 277-282, 2015.
(要約)
To investigate the effect of catechins on vascular endothelial growth factor (VEGF) production and cyclooxygenase-2 (COX-2) expression in human dental pulp cells (HDPC) stimulated with bacteria-derived factors or pro-inflammatory cytokines. Morphologically fibroblastic cells established from explant cultures of healthy human dental pulp tissues were used as HDPC. HDPC pre-treated with catechins, epigallocatechin-3-gallate (EGCG) or epicatechin gallate (ECG), were exposed to lipopolysaccharide (LPS), peptidoglycan (PG), interlukin-1β (IL-1β) or tumour necrosis factor-α (TNF-α). VEGF production was examined by enzyme-linked immunosorbent assay, and COX-2 expression was assessed by immunoblot. EGCG and ECG significantly reduced LPS- or PG-mediated VEGF production in the HDPC in a dose-dependent manner. EGCG also prevented IL-1β-mediated VEGF production. Although TNF-α did not enhance VEGF production in the dental pulp cells, treatment of 20 μg mL(-1) of EGCG decreased the level of VEGF. In addition, the catechins attenuated COX-2 expression induced by LPS and IL-1β. The up-regulated VEGF and COX-2 expressions in the HDPC stimulated with these bacteria-derived factors or IL-1β were diminished by the treatment of EGCG and ECG. These findings suggest that the catechins may be beneficial as an anti-inflammatory tool of the treatment for pulpal inflammation.
It has been shown that oral hygiene affects the onset of perioperative complications. The usefulness of perioperative oral function management aiming at the outbreak decrease in treatment complications and an early discharge was recognized. As a result, perioperative oral function management fee was founded at revision of medical service fees in Fiscal year 2012. In this clinical study, we evaluated the implementation of perioperative oral function management in Tokushima University Hospital. We examined 781 patients, including 563 patients for surgery and 218 patients for chemotherapy and radiotherapy. The mean age of patients was 58.8 ± 12.4 years old. The implementation rate of perioperative oral function management was 9.7% in the patients of surgery, and 17.4% in those of chemotherapy and radiotherapy. The highly required medical department was neurosurgery in the patients of surgery, and hematology in those of chemotherapy and radiotherapy. The mean number of tooth present was 21.3 ± 7.1 in the patients of surgery, and 19.8 ± 7.2 in those chemotherapy and radiotherapy. The rate of dental treatment was required in 40.5% of total patients who received surgery, and in 51.4% of patients who received chemotherapy and radiotherapy.The rate of patients who received denture treatment attained to 11.9% of the whole patients receiving surgery, and 13.3% of patients receiving chemotherapy and radiotherapy. It was revealed that there were many patients required potential demands in perioperative oral function management, and that there were many patients who need dental or denture treatment. We would like to develop perioperative oral function management by the interprofessional collaboration in health and social care.7月発行だが，6月号である．
Yukihiro Momota, Kohichi Kani, Hideyuki Takano, Fumihiro Matsumoto, Keiko Aota, Daisuke Takegawa, Yamanoi Tomoko, Kondo Chika, Shigemasa Tomioka and Masayuki Azuma : High-Wattage Pulsed Irradiation of Linearly Polarized Near-Infrared Light to Stellate Ganglion Area for Burning Mouth Syndrome, Case Reports in Dentistry, 2014.
(要約)
The purpose of this study was to apply high-wattage pulsed irradiation of linearly polarized near-infrared light to the stellate ganglion area for burning mouth syndrome (BMS) and to assess the efficacy of the stellate ganglion area irradiation (SGR) on BMS using differential time-/frequency-domain parameters (D parameters). Three patients with BMS received high-wattage pulsed SGR; the response to SGR was evaluated by visual analogue scale (VAS) representing the intensity of glossalgia and D parameters used in heart rate variability analysis. High-wattage pulsed SGR significantly decreased the mean value of VAS in all cases without any adverse event such as thermal injury. D parameters mostly correlated with clinical condition of BMS. High-wattage pulsed SGR was safe and effective for the treatment of BMS; D parameters are useful for assessing efficacy of SGR on BMS.
Daisuke Takegawa, Tadashi Nakanishi, Kouji Hirao, Hiromichi Yumoto, Kanako Takahashi and Takashi Matsuo : Modulatory roles of interferon-γ through indoleamine 2, 3-dioxygenase induction in innate immune response of dental pulp cells., Journal of Endodontics, 40, 9, 1382-1387, 2014.
(要約)
Marked infiltration of inflammatory cells such as activated T cells producing interferon-γ (IFN-γ) is observed in severe pulpitis. However, the roles of IFN-γ in the innate immune response of dental pulp have not been reported. Indoleamine 2, 3-dioxygenase (IDO) is a regulator of immune responses, and the IDO expression is induced by IFN-γ in many cells whose expression in dental pulp is unknown. The purpose of this study was to determine the role of IFN-γ in the immune response through microbial pattern recognition receptors (PRRs) such as Toll-like receptors or nucleotide-binding oligomerization domain-like receptors on the production of proinflammatory cytokines such as CXCL10 and interleukin (IL)-6 and the expression of IDO in cultured human dental pulp cells (HDPCs). HDPCs were established from explant cultures of healthy pulp tissues. CXCL10 and IL-6 production was determined using enzyme-linked immunosorbent assay. Confirmation of IDO localization in dental pulp tissues was examined using immunohistochemistry. IDO expression in HDPCs was analyzed by immunoblot. IFN-γ significantly up-regulated CXCL10 and IL-6 production in the HDPCs stimulated with ligands for PRRs in a concentration-dependent manner. The expression of IDO was detected in inflamed pulp tissue. In addition, IFN-γ in combination with the PRR ligands enhanced IDO expression in HDPCs compared with IFN-γ alone. Moreover, CXCL10 production in IFN-γ-stimulated HDPCs was inhibited by an IDO inhibitor. This study showed the synergistic effects by IFN-γ on cytokine production and IDO expression in HDPCs, suggesting that IFN-γ may modulate the innate immune response of dental pulp.
Hiromichi Yumoto, Kouji Hirao, Yuki Hosokawa, Hitomi Kuramoto, Daisuke Takegawa, Tadashi Nakanishi and Takashi Matsuo : The Roles of Odontoblasts in Dental Pulp Innate Immunity, Japanese Dental Science Review, 54, 3, 105-117, Aug. 2018.
(要約)
Odontoblasts located in the outermost layer of dental pulp form a natural barrier between mineralized tissues, dentin, and soft tissues, dental pulp, of the vital tooth, and they first recognize caries-related pathogens and sense external irritations. Therefore, odontoblasts possess a specialized innate immune system to fight oral pathogens invading into dentin. Generally, the rapid initial sensing of microbial pathogens, especially pathogen-associated molecular patterns (PAMPs) shared by microorganisms, are mediated by pattern recognition receptors (PRRs), such as Toll-like receptor and the nucleotide-binding oligomerization domain (NOD). The innate immune responses in odontoblasts initiated by sensing oral pathogens provide host protective events, such as inflammatory reactions, to produce a variety of pro-inflammatory mediators, including chemokines and cytokines. These attract various inflammatory cells and cause antibacterial reactions, such as the production of defensins, to kill microorganisms in the proximal region of the odontoblast layer. This review focuses on innate immunity, especially cellular and molecular mechanisms regarding the sensing of PAMPs from oral pathogens by PRRs, in odontoblasts and provides information for future studies for the development of novel therapeutic strategies, including diagnosis and treatment, to prevent exceeding dental pulp inflammation and preserve the dental pulp tissues.
Yuki Hosokawa, Hiromichi Yumoto, Kouji Hirao, Hitomi Kuramoto, Tadashi Nakanishi, Daisuke Takegawa and Takashi Matsuo : Anti-inflammatory effects of polyphenols on rat odontoblastic cells, 95th General Session & Exhibition of the International Association for Dental Research (San Francisco), Mar. 2017.
2.
Daisuke Takegawa, Tadashi Nakanishi, Kouji Hirao, Hiromichi Yumoto, Yuki Hosokawa and Takashi Matsuo : Interferon-gamma modulates the innate immune response in odontoblast-like cells, 95th General session and exhibition of the IADR, Mar. 2017.
3.
Tadashi Nakanishi, Daisuke Takegawa, Kouji Hirao, Hiromichi Yumoto, Yuki Hosokawa and Takashi Matsuo : Effect of interleukin-17A on CCL20 production from odontoblast-like cells, 95th General session and exhibition of the IADR, Mar. 2017.
4.
Tadashi Nakanishi, Daisuke Takegawa, Hiromichi Yumoto, Kouji Hirao and Takashi Matsuo : Interleukin-17 Regulates Inflammatory Mediator Expression in IL-1beta-stimulated Dental Pulp Cells, 93th General Session & Exhibition of the International Association for Dental Research, Boston (USA), Mar. 2015.
5.
Tadashi Nakanishi, Daisuke Takegawa, Kouji Hirao, Hiromichi Yumoto, Kanako Takahashi and Takashi Matsuo : Prostaglandin F2a Regulates Cytokine Expression in Dental Pulp Cells, 91th General Session & Exhibition of the IADR, Seattle, USA, Mar. 2013.
6.
Daisuke Takegawa, Tadashi Nakanishi, Kouji Hirao, Hiromichi Yumoto, Kanako Takahashi and Takashi Matsuo : Interferon-g modulates the innate immune response of dental pulp cells, 91th General Session & Exhibition of the IADR, Seattle, USA, Mar. 2013.