Hidemi Kurihara

Hiroshima University, Hirosima, Hiroshima, Japan

Are you Hidemi Kurihara?

Claim your profile

Publications (267)768.73 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Previously, we reported that brain-derived neurotrophic factor (BDNF) enhances periodontal tissue regeneration by inducing periodontal ligament cell proliferation in vivo. In addition, the down growth of gingival epithelial cells, which comprises a major obstacle to the regeneration was not observed. However, the underlying molecular mechanism is still unclear. Therefore, this study aimed to investigate the effect of BDNF on cell proliferation and apoptosis in human periodontal ligament cells (HPL cells) and human gingival epithelial cells (OBA9 cells) and to explore the molecular mechanism in vitro. HPL cells dominantly expressed a BDNF receptor, TrkB, and BDNF increased cell proliferation and ERK phosphorylation. However, its proliferative effect was diminished by a MEK1/2 inhibitor (U0126) and TrkB siRNA transfection. Otherwise, OBA9 cells showed a higher expression level of p75, which is a pan-neurotrophin receptor, than that of HPL cells. BDNF facilitated not cell proliferation but cell apoptosis and JNK phosphorylation in OBA9 cells. A JNK inhibitor (SP600125) and p75 siRNA transfection attenuated the BDNF-induced cell apoptosis. Moreover, OBA9 cells pretreated with SP600125 or p75 siRNA showed cell proliferation by BDNF stimulation, though it was reduced by U0126 and TrkB siRNA. Interestingly, overexpression of p75 in HPL cells up-regulated cell apoptosis and JNK phosphorylation by BDNF treatment. These results indicated that TrkB-ERK signaling regulates BDNF-induced cell proliferation, whereas p75-JNK signaling plays roles in cell apoptotic and cytostatic effect of BDNF. Overall, BDNF activates periodontal ligament cells proliferation and inhibits the gingival epithelial cells growth via the distinct pathway. This article is protected by copyright. All rights reserved.
    No preview · Article · Nov 2015 · Journal of Cellular Biochemistry
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the efficacy, safety, and clinical significance of trafermin, a recombinant human fibroblast growth factor (rhFGF)-2, for periodontal regeneration in intrabony defects in Phase III trials. Study A, a multi-center, randomized, double-blind, placebo-controlled study, was conducted at 24 centers. Patients with periodontitis with 4- and 3-mm or deeper probing pocket depth and intrabony defects, respectively, were included. A total of 328 patients were randomly assigned (2:1) to receive 0.3% rhFGF-2 or placebo, and 323 patients received the assigned investigational drug during flap surgery. One of the co-primary endpoints, the percentage of bone fill at 36 weeks after drug administration, was significantly greater in the rhFGF-2 group at 37.131% (95% confidence interval, CI 32.7502-41.5123, n = 208) than it was in the placebo group at 21.579% (95%CI 16.3571-26.8011, n = 100, p < 0.001). The other endpoint, the clinical attachment level regained at 36 weeks, was not significantly different between groups. Study B, a multi-center, randomized, blinded (patients and evaluators of radiographs), and active-controlled study was conducted at 15 centers to clarify the clinical significance of rhFGF-2. Patients with 6- and 4-mm or deeper probing pocket depth and intrabony defects, respectively, were included. A total of 274 patients were randomly assigned (5:5:2) to receive rhFGF-2, enamel matrix derivative (EMD), or flap surgery alone. A total of 267 patients received the assigned treatment during flap surgery. The primary endpoint, the linear alveolar bone growth at 36 weeks was 1.927 mm (95%CI 1.6615-2.1920, n = 108) in the rhFGF-2 group and 1.359 mm (95%CI 1.0683-1.6495, n = 109) in the EMD group, showing non-inferiority (a pre-specified margin of 0.3 mm) and superiority of rhFGF-2 to EMD. Safety problems were not identified in both studies. Therefore, trafermin is an effective and safe treatment for periodontal regeneration in intrabony defect, and its efficacy was superior in rhFGF-2 compared to EMD treatments. This article is protected by copyright. All rights reserved.
    No preview · Article · Nov 2015 · Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: The gingival epithelium plays an important role in protecting against the invasion of periodontal pathogens, and the permeability of gingival epithelial cells has been implicated in the initiation of periodontitis. Azithromycin (AZM) has been used in the treatment of chronic inflammatory airway diseases because it regulates cell-cell contact in airway epithelial cells. Therefore, AZM may also regulate barrier function in gingival epithelial cells. In the present study, we examined the effects of AZM on the permeability of human gingival epithelial cells (HGEC) under inflammatory conditions in vitro. Materials and methods: HGEC were stimulated by tumor necrosis factor-α (TNF-α) in the presence of AZM or p38 MAP kinase and ERK inhibitors. Permeability was assessed based on transepithelial electrical resistance (TER). The expression of E-cadherin, phosphorylated p38 MAP kinase, and ERK was analyzed by Western blotting. Results: TNF-α decreased TER in HGEC, and AZM and the p38 MAP kinase and ERK inhibitors recovered this decrease. AZM inhibited the phosphorylation of ERK and p38 MAP kinase in TNF-α-stimulated HGEC. Furthermore, AZM recovered the decrease in E-cadherin expression in HGEC stimulated with TNF-α. Conclusions: These results suggested that AZM regulated gingival epithelial permeability through p38 MAP kinase and ERK signaling, and may contribute to suppress the inflammation in gingival tissue.
    No preview · Article · Nov 2015 · Archives of oral biology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Periodontitis is the most prevalent infectious disease caused by periodontopathic bacteria and is also a chronic inflammatory disease. Gingival crevicular fluid (GCF) is an inflammatory exudate that seeps into the gingival crevices or periodontal pockets around teeth with inflamed gingiva, and contains various materials including leukocytes and cytokines. Since gingival epithelial cells, which form a barrier against bacterial challenges, are affected by GCF, cytokines or other materials contained within GCF are engaged in the maintenance and disruption of the epithelial barrier. Accordingly, its compositional pattern has been employed as a reliable objective index of local inflammation. Transforming growth factor β1 (TGF-β1) levels in GCF were previously shown to be markedly higher in patients with periodontitis than in healthy subject. However, it currently remains unclear how TGF-β1 affects gingival epithelial cell growth or apoptosis; therefore, elucidating the mechanism responsible may lead to a deeper understanding of pathogenic periodontitis. In the present study, the human gingival epithelial cell line, OBA9 cells were stimulated with recombinant TGF-β1. Apoptosis-related protein levels were determined by Western blotting. Caspase-3/7 activity was measured with a Caspase-Glo assay kit. Surviving and apoptotic cells were detected using an MTS assay and TUNEL staining, respectively. TGF-βRI siRNA and smad2 siRNA were transfected into cells using the lipofectamine RNAiMAX reagent. TGF-β1 elevated caspase-3 activity and the number of TUNEL-positive apoptotic cells in OBA9 cells. Furthermore, while the levels of the pro-apoptotic proteins Bax, Bak, Bim, and Bad were increased in OBA9 cells stimulated with TGF-β1, the TGF-β1 treatment also decreased the levels of anti-apoptotic proteins such as Bcl-2 and Bcl-xL in a time-dependent manner. Additionally, TGF-β1 up-regulated the protein levels of cleaved caspase-9. These results indicated that TGF-β1-induced apoptosis was involved in a mitochondria-related intrinsic pathway. TGF-β1 phosphorylated smad2 in OBA9 cells and this phosphorylation was clearly reduced by SB431542 (a TGF-β type I receptor inhibitor). Consistent with this result, SB431542 or smad2 siRNA-induced reductions in smad2 protein expression levels attenuated TGF-β1-induced apoptosis. On the other hand, the ligation of TGF-β1 on its receptor also stimulated the phosphorylation of Erk and Akt, which are smad2-independent pathways. However, the inhibition of Erk/Akt signaling pathways by U0126, a MEK-Erk inhibitor and LY294002, a PI3Kinase-Akt inhibitor, augmented TGF-β1-induced apoptosis in OBA9 cells. Taken together, the results of present study demonstrated that TGF-β1 activated both the smad2 and Erk/Akt cascades via its receptor on gingival epithelial cells, even though these two pathways have opposite roles in cell death and survival, and the culmination of these signaling events induced mitochondria-dependent apoptosis in gingival epithelial cells. Based on the results of the present study, we herein proposed for the first time, that TGF-β1 is a novel target cytokine for monitoring the progression of periodontal disease. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Apr 2015 · Cytokine
  • [Show abstract] [Hide abstract]
    ABSTRACT: The transplantation of mesenchymal stromal cells (MSCs) to damaged tissue has attracted attention in scientific and medical fields as an effective regenerative therapy. Nevertheless, additional studies are required to develop an MSC transplant method for bone regeneration because the use of an artificial scaffold restricts the number of transplanted cells and their function. Furthermore, regulating the degree of cell differentiation in vitro is desirable for a more effective regenerative therapy. To address these unresolved issues, with the use of a self-produced extracellular matrix (ECM), we developed clumps of an MSC/ECM complex (C-MSCs). MSCs isolated from rat femur were cultured in growth medium supplemented with 50 μg/mL of ascorbic acid for 7 days. To obtain C-MSCs, confluent cells were scratched with the use of a micropipette tip to roll up the cellular sheet, which consisted of ECM produced by the MSCs. The biological properties of C-MSCs were assessed in vitro and their bone regenerative activity was tested by use of a rat calvarial defect model. Immunofluorescent confocal microscopic analysis revealed that type I collagen formed C-MSCs. Osteopontin messenger RNA expression and amount of calcium content were higher in C-MSCs cultured in osteo-inductive medium than those of untreated C-MSCs. The transplantation of osteogenic-differentiated C-MSCs led to rapid bone regeneration in the rat calvarial defect model. These results suggest that the use of C-MSCs refined by self-produced ECM, which contain no artificial scaffold and can be processed in vitro, may represent a novel tissue engineering therapy. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Mar 2015 · Cytotherapy
  • [Show abstract] [Hide abstract]
    ABSTRACT: A large number of individuals have halitosis. The total amount of volatile sulfur compounds, which are the main cause of halitosis, has been correlated with periodontitis following bacterial infection. In the present study, Porphyromonas gingivalis (Pg), a major periodontopathogenic bacterium, was isolated from patients with halitosis by the amplification of 16s-rRNA, and the ability of isolated Pg to produce methyl mercaptan (CH3 SH) was determined in order to clarify the relationship between halitosis and Pg infection. CH3 SH concentrations were measured in patients using Oral Chroma. The production of CH3 SH by Pg standard and clinical strains was also measured in vitro. Real-time-PCR was performed to compare the expression of mgl mRNA (which encoded L-methionine-a-deamino-g-mercaptomethane-lyase) among the Pg strains. The production of CH3 SH and the expression of mgl mRNA were also determined in order to assess the effects of oriental medicine. The production of CH3 SH and the expression of mgl mRNA strongly correlated with each other in the presence of L-methionine. The expression of mgl mRNA by Pg W83 was strongly inhibited by magnoliaceae. The production of CH3 SH was correlated with the expression of mgl. Furthermore, the oriental medicine, magnoliaceae, may represent a potential treatment for halitosis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    No preview · Article · Feb 2015 · Oral Diseases
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: The purpose of this study is to evaluate whether β-tricalcium phosphate (β-TCP) could be a promising modality to help augment alveolar bone in periodontal tissue regeneration by bone marrow mesenchymal stem cells (BMMSCs). Methods: Expanded BMMSCs and atelocollagen (Col) were mixed together (MSC/Col). A combination of β-TCP with MSC/Col was also prepared (MSC/Col/TCP). MSC/Col/TCP or MSC/Col was transplanted into experimental periodontal Class III furcation defects that had been exposed to inflammation in beagle dogs. Periodontal tissue regeneration was evaluated by histologic and morphometric analyses at 4 and 8 weeks after transplantation. Results: MSC/Col and MSC/Col/TCP enhanced periodontal tissue regeneration compared to Col and TCP/Col according to hematoxylin and eosin staining. The percentage of new cementum length in the MSC/Col/TCP group was not significantly different from that in the MSC/Col group at 4 and 8 weeks. On the other hand, the percentage of new bone area in the MSC/Col/TCP group was much higher than that in the MSC/TCP group at 4 weeks. However, at 8 weeks, no significant difference in new bone area was found between the two groups. In the MSC/Col/TCP group, β-TCP was surrounded by newly formed bone. Multinucleated cells, which were positive for osteopontin and tartrate-resistant acid phosphatase, were present in the interconnected macropores of β-TCP. Conclusion: These findings suggest that β-TCP is applicable as a scaffold for BMMSCs transplantation and helps augment alveolar bone without impairing regeneration of cementum.
    No preview · Article · Dec 2014 · Journal of Periodontology
  • Source
    T Yoshimoto · T Fujita · K Ouhara · M Kajiya · H Imai · H Shiba · H Kurihara
    [Show abstract] [Hide abstract]
    ABSTRACT: Apoptosis is thought to contribute to the progression of periodontitis. It has been suggested that the apoptosis of epithelial cells may contribute to the loss of epithelial barrier function. Smad2, a downstream signaling molecule of TGF-β receptors (TGF-βRs), is critically involved in apoptosis in several cell types. However, the relationship between smad2 and bacteria-induced apoptosis has not yet been elucidated. It is possible that the regulation of apoptosis induced by periodontopathic bacteria may lead to novel preventive therapies for periodontitis. Therefore, in the present study, we investigated the involvement of smad2 phosphorylation in apoptosis of human gingival epithelial cells induced by Aggregatibacter actinomycetemcomitans (Aa). Aa apparently induced the phosphorylation of smad2 in primary human gingival epithelial cells (HGECs) or the human gingival epithelial cell line, OBA9 cells. In addition, Aa induced phosphorylation of the serine residue of the TGF-β type I receptor (TGF-βRI) in OBA9 cells. SB431542 (a TGF-βRI inhibitor) and siRNA transfection for TGF-βRI, which reduced both TGF-βRI mRNA and protein levels, markedly attenuated the Aa-induced phosphorylation of smad2. Furthermore, the disruption of TGF-βRI signaling cascade by SB431542 and siRNA transfection for TGF-βRI abrogated the activation of cleaved caspase-3 expression and repressed apoptosis in OBA9 cells treated with Aa. Thus, Aa induced apoptosis in gingival epithelial cells by activating the TGF-βRI-smad2-caspase-3 signaling pathway. The results of the present study may suggest that the periodontopathic bacteria, Aa, activates the TGF-βR/smad2 signaling pathway in human gingival epithelial cells and induces apoptosis in epithelial cells, which may lead to new therapeutic strategies that modulate the initiation of periodontitis.
    Full-text · Article · Sep 2014 · Journal of Dental Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is important to implement good quality chest compressions for cardiopulmonary resuscitation (CPR). This manikin study examined the effects of different compression rates on chest compression depth variables using a metronome sound guide. Fifty sixth-year dentistry students participated in the study. Each participant performed CPR at 3 different compression rates, 110, 100, and 90 compressions per min (pace-110-g, pace-100-g, and pace-90-g) for 2 consecutive one-minute sets with a ten-second break between the sets. The percentage of compressions deeper than 5 cm at pace-110-g decreased significantly from 22.1 ± 4.7% in the first set to 16.7 ± 4.4%* in the second set (*p < 0.05 vs. the first set). However, no significant differences were observed between the first and second sets at pace-100-g and pace-90-g. The results obtained for pace-110-g were compared in detail by gender. In the male group, the percentage of compressions deeper than 5 cm was 43.5 ± 7.5% in the first set, and this decreased significantly to 34.6 ± 7.6%* in the second set (*p < 0.001 vs. the first set). However, the percentage of compressions deeper than 5 cm in the female group was 2.3 ± 1.6%* in the first set and 0.2 ± 0.2%* in the second set (*p < 0.05 vs. male). Our study demonstrated that the compression pace of 110 compressions per min was inadequate to provide chest compressions of an appropriate depth, which decreased rapidly. Therefore, limiting the rate of compressions to within a certain number per min may contribute to minimizing deteriorations in compression depth in hands-only CPR.
    No preview · Article · Sep 2014 · Hiroshima journal of medical sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background and Objective Brain-derived neurotrophic factor (BDNF) promotes the regeneration of periodontal tissue. Although a local inflammatory step is required to initiate the subsequent process of tissue regeneration, excessive inflammation may inhibit or delay tissue regeneration. Therefore, the regulation of inflammation is essential for periodontal tissue regeneration. In the present study, we examined the influence of BDNF on the human microvascular endothelial cell (HMVEC) barrier dysfunction induced by interleukin (IL)-1β or tumor necrosis factor (TNF)-α to determine the effects of BDNF on the regulation of local inflammation in periodontal tissue regeneration.Material and Methods Endothelial permeability was analyzed using a Dextran transport assay with transwell plates. The expression of vascular endothelial (VE)-cadherin was assessed by immunoblotting and immunofluorescence microscopy.ResultsBDNF (25 ng/mL) inhibited increase induced in endothelial permeability by IL-1β and TNF-α. IL-1β and TNF-α decreased VE-cadherin protein levels, while BDNF recovered the reduction in HMVECs. BDNF protected the increase induced in endothelial permeability by IL-1β and TNF-α through TrkB. The single addition of BDNF into the culture increased the expression of VE-cadherin in HMVECs.ConclusionBDNF played an important role in inhibiting endothelial barrier dysfunction, which suggests that it may assist in enhancing periodontal tissue regeneration.
    No preview · Article · Sep 2014 · Journal of Periodontal Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background and objective: Periodontitis is an infectious disease caused by an interaction between the host and periodontopathogenic bacteria. Regulating the immune response in human gingival epithelial cells (HGEC) may contribute to the prevention of periodontitis. Irsogladine maleate (IM) has previously been shown to regulate inflammation and the cell-cell junctional barrier in HGEC. In addition to these functions, control of bacterial recognition is important for preventing inflammation in periodontal tissue. Innate immunity in gingival epithelium is the first line of defense and plays a crucial role against bacterial challenge. Therefore, the effect of IM on regulating toll-like receptor 2 (TLR2), which is part of the innate immunity, was determined in this study. Material and methods: OBA-9, an immortalized human gingival epithelial cell line, and primary cultured HGEC were used in this study. Real-time PCR and western blotting were performed in OBA-9 or HGEC stimulated with whole cells of Porphyromonas gingivalis or with lipopolysaccharide (LPS) derived from P. gingivalis (PgLPS) in the presence or absence of IM to determine expression of TLR2 mRNA and production of TLR2 protein. Small interfering RNA (siRNA) against TLR2 was transfected into OBA-9 to clarify the association between the induction of TLR2 and interleukin-8 (IL-8) production. Results: The addition of IM into P. gingivalis or PgLPS-induced OBA-9 suppressed IL-8 production (p < 0.01). The addition of IM also abolished the induction of TLR2 by P. gingivalis or PgLPS in OBA-9 and primary cultured HGEC (p < 0.01). The suppressive effect of IM on the induction of TLR2 was also confirmed by immunohistostaining. Stimulation with peptidoglycan, a specific ligand for TLR2, suppressed the expression of toll-like receptor 4 (TLR4) mRNA in the presence of IM (p < 0.01). However, LPS derived from Escherichia coli, a ligand for TLR4, did not induce the expression of TLR2 mRNA. The PgLPS-induced expression of TLR4 mRNA was abolished by IM. Knockdown of TLR2 by siRNA transfection resulted in a weaker response of induction of IL8 mRNA in P. gingivalis or PgLPS-stimulated OBA-9. Conclusion: These results suggest that IM suppresses the induction of IL-8 production by regulating increased levels of TLR2.
    No preview · Article · Sep 2014 · Journal of Periodontal Research
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background and Objective Migration of the junctional epithelium occurs in association with the formation of a periodontal pocket. Although the migration of junctional epithelium is known to be related to the proliferation and migration of gingival junctional epithelial cells, the mechanism has not been clarified. In patients with periodontitis, the levels of interleukin-8 (IL-8) in both gingival tissue and gingival crevicular fluid are dramatically increased. IL-8 has broad bioactive functions. In this study, we examined the role of IL-8 in DNA synthesis, migration and protection against apoptosis in cultured human gingival epithelial cells (HGEC).Material and MethodsDNA synthesis was estimated by measuring the incorporation of bromodeoxyuridine. The migration of gingival epithelial cells was assessed in a wound-healing assay. The expression of integrin beta-1 was analyzed using immunofluorescence confocal microscopy and western blotting. Cleaved caspase-3 was detected using western blotting and a Caspase-Glo assay kit.ResultsIL-8 increased the synthesis of DNA in HGEC, and the maximal effect was seen at 25 or 50 ng/mL of IL-8. In addition, 50 ng/mL of IL-8 induced cell migration, and a neutralizing antibody of integrin beta-1 inhibited the migration. IL-8 also activated expression of integrin beta-1. Furthermore, IL-8 reduced the Aggregatibacter actinomycetemcomitans-induced increase in caspase-3 expression in HGEC.ConclusionIL-8 may facilitate the migration of gingival junctional epithelium by enhancing DNA synthesis, migration and preventing apoptosis of gingival epithelial cells.
    Full-text · Article · Sep 2014 · Journal of Periodontal Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gingival epithelium is the primary barrier against microorganism invasion and produces inflammatory cytokines. Amphotericin B, a major antifungal drug, binds to cholesterol in the mammalian cell membrane in addition to fungal ergosterol. Amphotericin B has been shown to regulate inflammatory cytokines in host cells. To investigate the suppressive effect of amphotericin B on the gingival epithelium, we examined the expression of interleukin (IL)-8 and IL-6 and involvement of MAP kinase in human gingival epithelial cells (HGEC) stimulated by Aggregatibacter actinomycetemcomitans. Amphotericin B and the p38 MAP kinase inhibitor down-regulated the A. actinomycetemcomitans-induced increase in the expression of IL-8 and IL-6 at the mRNA. The ERK inhibitor suppressed the A. actinomycetemcomitans-induced IL-8 mRNA expression. Amphotericin B inhibited the A. actinomycetemcomitans-induced phosphorylation of ERK and p38 MAP kinase. Furthermore, amphotericin B inhibited the A. actinomycetemcomitans-induced production of prostaglandin E2. These results suggest that amphotericin B regulate inflammatory responses in HGEC.
    No preview · Article · Aug 2014 · Cellular Immunology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aim: To examine the in vitro effects of LL37 on the expression of vascular endothelial growth factor (VEGF) in human pulp cells and to identify the intracellular signalling pathway involved. Methodology: Pulp cells at passage 6 were treated with 10 μg mL(-1) synthesized LL37, and an inhibition assay was performed with MAPK or NF-κB inhibitors to determine the possible signalling pathway. VEGF mRNA, VEGF protein and phosphorylated ERK1/2 levels were determined by real-time PCR, ELISA and Western blot, respectively. Data were analysed using t-tests. Results: LL37 significantly increased both the mRNA and protein levels of VEGF in pulp cells (P < 0.01). However, pre-treatment with an ERK kinase inhibitor suppressed these increases. Furthermore, the inhibitor blocked LL37-induced ERK1/2 phosphorylation. Conclusions: LL37 activated the ERK pathway to boost VEGF secretion from human pulp cells. Because of this angiogenic effect and its reported induction of pulp cell migration and antimicrobial activity against cariogenic bacteria, LL37 may be applicable as a pulp capping material.
    No preview · Article · Aug 2014 · International Endodontic Journal
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: In periodontitis, gingival epithelium represents the first line of defense against pathological microbial invasion or challenge and plays a crucial role as a mechanical barrier. Transforming growth factor β1 (TGF-β1) is important cytokines with pleiotrophic properties to regulate a broad spectrum of cellular processes including cell growth, differentiation, and apoptosis. Interestingly, TGF-β1 levelis elevated in gingival crevicular fluid obtained from periodontal pockets, however, the role of TGF-β1 on gingival epithelium is still unclear. Accordingly, in this study, we aimed to investigate whether TGF-β1 affects gingival epithelial cells viability and to reveal its molecular mechanism. Method: OBA9 cells (an immortalized human gingival epithelial cell line, kindly gifted by Prof. Murakami, Osaka University) were cultured with Humedia-KB2 medium. OBA9 cells were treated with TGF-β1, then, to assess the cell viability and apoptotic cells, MTS assay and TUNEL staining were conducted. The signal transduction molecules relating to the cell death were examined by Western blotting. Furthermore, to investigate the role of TGF-β type I receptor(TβRI)on the cell viability and apoptosis in the signaling event, siRNA transfection was performed. Result: TGF-β1 reduced the cell viability and increased apoptotic cells. Consistent with this result, the level of cleaved caspase3 and caspase9 were remarkably elevated. TGF-β1 up-regulated the expression of mitochondria-dependent apoptosis related proteins, such as Bak, Bax, Bim, and Bad. Otherwise, anti-apoptotic molecules, Bcl-2, Bcl-x(L) were obviously decreased in OBA9 cells by TGF-β1 treatment. TGF-β1 treatment facilitated the phosphorylation of smad2, which is downstream target of TβRI. The disruption of the TβRI by TβRI siRNA abrogated its phosphorylation and cleaved caspase3/9 expression induced by TGF-β1. TβRI siRNA significantly attenuated TGF-β1-induced cell apoptosis. Conclusion: These findings suggested that TGF-β1 activates mitochondria-dependent apoptosis in gingival epithelial cells via TβRI -smad2 pathway. TGF-β1 may play a role in the onset or progression of periodontitis.
    No preview · Conference Paper · Jun 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background/purpose Periodontitis is an infectious inflammatory disease. Gingival epithelium is the primary barrier against invasion of microorganisms and produces inflammatory cytokines. Our previous studies showed that regulating the function on the gingival epithelium was useful in suppressing the onset of periodontal disease. Houttuynia cordata is commonly used in traditional oriental medicine formulations and has been associated with a broad range of pharmacological activities. To investigate the potential of H. cordata as a preventive medicine, we examined the effect of H. cordata on the expression of inflammatory-related genes in human gingival epithelial cells (HGECs) exposed to Aggregatibacter actinomycetemcomitans. Materials and methods The messenger RNA (mRNA) levels of matrix metalloproteinase-3 (MMP-3), interleukin (IL)-8, IL-6, and intercellular adhesion molecule-1 (ICAM-1) were determined by real-time polymerase chain reaction. Results A. actinomycetemcomitans facilitated the mRNA expression of MMP-3, IL-8, IL-6, and ICAM-1 in HGECs, whereas these mRNA levels were attenuated by the H. cordata treatment. In addition, the extracellular signal-regulated kinase (ERK) signaling cascade, which was reported to be involved in A. actinomycetemcomitans-induced increases in MMP-3, IL-8, or ICAM-1, was disturbed by the H. cordata treatment in HGECs. Furthermore, H. cordata also inhibited the tumor necrosis factor-α-induced enhancement in these genes in HGECs. Conclusion These results suggest that H. cordata suppresses the expression of inflammatory-related genes in gingival epithelial cells by inhibiting the ERK signaling cascade. This might result in the suppression of inflammatory response in gingival epithelium, thereby contributing to the prevention of periodontitis.
    Full-text · Article · Jun 2014 · Journal of dental sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Brain-derived neurotrophic factor (BDNF) activates its receptor TrkB, and promotes neuronal survival, differentiation, and synaptic functions. Furthermore, we have revealed that BDNF can also regulate cementoblast differentiation and cellular survival via TrkB–ERK/Akt signaling cascade, which, in turn, results in the induction of periodontal tissue regeneration. Recently, using in silico screening with a BDNF loop-domain pharmacophore, a small molecule BDNF mimetic, called LM22A-4 that can facilitate TrkB signaling in hippocampal neurons to prevent cell death, was identified. Therefore, this study aimed to investigate the effect of LM22A-4 on cementoblast differentiation and its molecular mechanism. LM22A-4 and BDNF stimulation was found to enhance OPN, ALPase, and OC mRNA expression in immortalized human cementoblast-like (HCEM) cells, indicating cementoblast differentiation. In addition, similar to this result, both LM22A-4 and BDNF treatment facilitated TrkB phosphorylation and TrkB binding to adaptor proteins, such as Shc, GRB2, and SOS1, indicating TrkB activation. Importantly, the downstream target ERK and Akt was also phosphorylated by LM22A-4 and BDNF stimulation. Moreover, BDNF mimetic stimulation transactivated ERK from the cytoplasm into the nuclei in HCEM cells. It is noteworthy that a tyrosine kinase receptor inhibitor, K252a, an MEK–ERK inhibitor (U0126), and a PI3Kinase–Akt inhibitor (LY294002) remarkably attenuated TrkB, ERK, and Akt phosphorylation as well as increase of OPN mRNA expression in the HCEM cells, respectively. These findings suggest that the small molecule BDNF mimetic LM22A-4 regulates cementoblast differentiation via the TrkB–ERK/Akt signaling cascade. Therefore, this small compound may lead to the development of a novel therapeutic approach for periodontal tissue regeneration.
    No preview · Article · Apr 2014 · International immunopharmacology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Alzheimer's disease (AD) is the most common form of dementia. To date, several genes have been identified as the cause of AD, including PSEN1, PSEN2, and APP. The association between APOE and late-onset AD has also been reported. We here used a bench top next-generation sequencer, which uses an integrated semiconductor device, detects hydrogen ions, and operates at a high-speed using nonoptical technology. We examined 45 Japanese AD patients with positive family histories, and 29 sporadic patients with early onset (<60-year-old). Causative mutations were detected in 5 patients in the familial group (11%). Three patients had a known heterozygous missense mutation in the PSEN1 gene (p.H163R). Two patients from 1 family had a novel heterozygous missense mutation in the PSEN1 gene (p.F386L). In the early onset group, 1 patient carrying homozygous APOEε4 had a novel heterozygous missense mutation in the PSEN2 gene (p.T421M). Approximately 43% patients were APOEε4 positive in our study. This new sequencing technology is useful for detecting genetic variations in familial AD.
    No preview · Article · Jan 2014 · Neurobiology of aging
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to observe the regenerative effect of brain-derived neurotrophic factor (BDNF) in a non-human primate furcation defect model. Class II furcation defects were created in the first and second molars of 8 non-human primates to simulate a clinical situation. The defect was filled with either, Group A: BDNF (500 µg/ml) in high-molecular weight-hyaluronic acid (HMW-HA), Group B: BDNF (50 µg/ml) in HMW-HA, Group C: HMW-HA acid only, Group D: empty defect, or Group E: BDNF (500 µg/ml) in saline. The healing status for all groups was observed at different time-points with micro computed tomography. The animals were euthanized after 11 weeks, and the tooth-bone specimens were subjected to histologic processing. The results showed that all groups seemed to successfully regenerate the alveolar buccal bone, however, only Group A regenerated the entire periodontal tissue, i.e., alveolar bone, cementum and periodontal ligament. It is suggested that the use of BDNF in combination with a scaffold such as the hyaluronic acid in periodontal furcation defects may be an effective treatment option.
    Full-text · Article · Jan 2014 · PLoS ONE
  • T. Iida · T. Yokota · H. Shiba · H. Suzuki · H. Kurihara · K. Yanaga
    [Show abstract] [Hide abstract]
    ABSTRACT: Bezoars are concretions of foreign matter in the stomach which rarely cause gastrointestinal obstruction. We report a case of small intestine obstruction due to bezoars that was formed in the residual stomach. A 62-year-old woman was admitted to our hospital with epigastric pain, nausea and abdominal distention. CT revealed a gas-containing mass in the remnant stomach. After hospitalization, she presented with symptoms of bowel obstruction. Decompression of the bowel with an ileus tube failed to resolve abdominal distension. A radiographic study throgh the ileus tube and subsequent CT revealed that migration of the bezoars led to secondary small intestinal obstruction. She underwent emergency laparotomy, in which beads-shaped masses were observed at 170cm oral to the terminal ileum. The small intestine was partially resected, and her postoperative course was uneventful except for temporary paralytic ileus. The patient was discharged from the hospital 20 days after the operation. To date, 196 cases of small intestinal obstruction due to phytobezoars including this case have been reported in the Japanease literature, of which phytobezoars were surgically removed in 66.5%. If gastric bezoars dislodge into the intestine, operation is usually required.
    No preview · Article · Nov 2013

Publication Stats

7k Citations
768.73 Total Impact Points


  • 1996-2015
    • Hiroshima University
      • • Department of Periodontal Medicine
      • • Department of Life Sciences
      • • Faculty of Dentistry
      • • School of Dentistry
      Hirosima, Hiroshima, Japan
  • 2010
    • Fukuoka Dental College
      • Department of General Dentistry
      Hukuoka, Fukuoka, Japan
  • 1990-2009
    • Okayama University
      • • Department of Microbiology
      • • Dental School
      • • Department of Periodontal Science (Periodontology and Endodontology)
      Okayama, Okayama, Japan
  • 2003
    • The Forsyth Institute
      Cambridge, Massachusetts, United States
    • Himeji Institute of Technology
      • Faculty of Science
      Himezi, Hyōgo, Japan
  • 2002
    • Kumamoto University
      • Institute of Molecular Embryology and Genetics (IMEG)
      Kumamoto, Kumamoto Prefecture, Japan
  • 1993-2000
    • The University of Tokyo
      • • Department of Cardiovascular Medicine
      • • Division of Internal Medicine
      • • School of Medicine
      白山, Tōkyō, Japan
  • 1999
    • Kyoto University
      • Graduate School of Human and Environmental Studies
      Kyoto, Kyoto-fu, Japan
  • 1998
    • École Nationale Vétérinaire de Toulouse
      Tolosa de Llenguadoc, Midi-Pyrénées, France
  • 1997
    • Sheba Medical Center
      Gan, Tel Aviv, Israel
  • 1989
    • University of Tsukuba
      • Institute of Basic Medical Sciences
      Tsukuba, Ibaraki, Japan
  • 1986
    • Rikkyo University
      • Institute for Atomic Energy
      Edo, Tōkyō, Japan