[show abstract][hide abstract] ABSTRACT: Because of its high oxygen demands, neural tissue is predisposed to oxidative stress. Here, our aim was to clarify the cellular localization of antioxidant enzymes in the trigeminal ganglion. We found that the transcriptional factor Sox10 is localized exclusively in satellite glial cells (SGCs) in the adult trigeminal ganglion. The use of transgenic mice that express the fluorescent protein Venus under the Sox10 promoter enabled us to distinguish between neurons and SGCs. Although both superoxide dismutases 1 and 2 were present in the neurons, only superoxide dismutase 1 was identified in SGCs. The enzymes relevant to hydrogen peroxide degradation displayed differential cellular localization, such that neurons were endowed with glutathione peroxidase 1 and thioredoxin 2, and catalase and thioredoxin 2 were present in SGCs. Our immunohistochemical finding showed that only SGCs were labeled by the oxidative damage marker 8-hydroxy-2'-deoxyguanosine, which indicates that the antioxidant systems of SGCs were less potent. The transient receptor potential vanilloid subfamily member 1 (TRPV1), the capsaicin receptor, is implicated in inflammatory hyperalgesia, and we demonstrated that topical capsaicin application causes short-lasting mechanical hyperalgesia in the face. Our cell-based assay revealed that TRPV1 agonist stimulation in the presence of TRPV1 overexpression caused reactive oxygen species-mediated caspase-3 activation. Moreover, capsaicin induced the cellular demise of primary TRPV1-positive trigeminal ganglion neurons in a dose-dependent manner, and this effect was inhibited by a free radical scavenger and a pancaspase inhibitor. This study delineates the localization of antioxidative stress-related enzymes in the trigeminal ganglion and reveals the importance of the pivotal role of reactive oxygen species in the TRPV1-mediated caspase-dependent cell death of trigeminal ganglion neurons. Therapeutic measures for antioxidative stress should be taken to prevent damage to trigeminal primary sensory neurons in inflammatory pain disorders.
[show abstract][hide abstract] ABSTRACT: The targeting of antioxidant systems that allow stem-like cancer cells to avoid the adverse consequences of oxidative stress might be expected to improve the efficacy of cancer treatment. Here we show that head and neck squamous cell carcinoma (HNSCC) cells that express variant isoforms of CD44 (CD44v) rely on the activity of the cystine transporter subunit xCT for control of their redox status. xCT inhibition selectively induces apoptosis in CD44v-expressing tumor cells without affecting CD44v-negative differentiated cells in the same tumor. In contrast to CD44v-expressing undifferentiated cells, CD44v-negative differentiated cells manifest epidermal growth factor receptor (EGFR) activation and rely on EGFR activity for their survival. Combined treatment with inhibitors of xCT-dependent cystine transport and of EGFR resulted in a synergistic reduction of EGFR-expressing HNSCC tumor growth. Thus, xCT-targeted therapy may deplete CD44v-expressing undifferentiated HNSCC cells and concurrently sensitize the remaining differentiating cells to available treatments including EGFR-targeted therapy.
[show abstract][hide abstract] ABSTRACT: Bone defects caused by traumatic bone loss or tumor dissection are now treated with auto- or allo-bone graft, and also occasionally by artificial bone transplantation, particularly in the case of large bone defects. However, artificial bones often exhibit poor affinity to host bones followed by bony union failure. Thus therapies combining artificial bones with growth factors have been sought. Here we report that platelet derived growth factor bb (PDGFBB) promotes a significant increase in migration of PDGF receptor α (PDGFRα)-positive mesenchymal stem cells/pre-osteoblastic cells into artificial bone in vivo. Growth factors such as transforming growth factor beta (TGFβ) and hepatocyte growth factor (HGF) reportedly inhibit osteoblast differentiation; however, PDGFBB did not exhibit such inhibitory effects and in fact stimulated osteoblast differentiation in vitro, suggesting that combining artificial bones with PDGFBB treatment could promote host cell migration into artificial bones without inhibiting osteoblastogenesis.
Biochemical and Biophysical Research Communications 04/2012; 421(4):785-9. · 2.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: Aims: To compare patients with combined tension-type headache and myofascial temporomandibular disorder (TMD) with control subjects on two measures of central processing-ie, temporal summation and aftersensations to heat stimulation in the trigeminal nerve and spinal nerve territories. Methods: A novel heat stimulation protocol was used in which 13 females with tension-type headache/TMD and 20 female controls were exposed to 11 painful heat stimuli at a rate of 0.33 Hz. Two temperature ranges (low, 44°C to 46°C; high, 45°C to 47°C) were tested on the cheek and arm in separate trials. Perceived pain was rated on a 100-mm visual analog scale after the second, sixth, and eleventh stimulus presentation and every 15 seconds after the final stimulus presentation (aftersensations) for up to 3 minutes. The duration of aftersensations was compared using the student unpaired t test with Welch correction. Results: Temporal summation was not observed in any of the groups, but aftersensations were consistently reported. The aftersensations lasted longer in tension-type headache/TMD patients (right cheek, 100.4 ± 62.0 seconds; right arm, 115.4 ± 64.0 seconds) than in controls (right cheek, 19.5 ± 2.5 seconds; right arm, 20.3 ± 2.7 seconds) (P < .05). A cutoff value (right cheek, 44.6 seconds; right arm, 41.5 seconds) provided a sensitivity and specificity of 0.77 and 0.95, respectively, with the high stimulus protocol. Conclusion: The results from this pilot study suggest that aftersensations to painful heat stimulation can appear without temporal summation. Furthermore, the developed test protocol has a good predictive value and may have the potential to discriminate between tension-type headache/TMD patients and control subjects.
Journal of orofacial pain 01/2012; 26(4):288-95. · 2.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: To gain insight into the impact of periodontal surgery on oral health-related quality of life (QoL) of patients with periodontitis.
Study participants were recruited from moderate to severe periodontitis patients. After initial periodontal therapy, participants received periodontal surgery. Oral Health-related Quality of Life Model for Dental Hygiene (OHRQL) was used to assess participant's QoL at each time point of periodontal evaluation (baseline, at least 3 weeks after initial therapy and 3-4 months after surgery).
A total of 21 patients completed OHRQL assessment after surgery. Compared with baseline, a progressive improvement in periodontal parameters was observed during the periodontal therapy. The total mean OHRQL score at baseline (25.5 ± 11.4) was significantly reduced (improved) after initial therapy and after surgery (16.7 ± 9.5 and 15.0 ± 9.7, respectively; p < 0.01). However, no significant difference was found between the OHRQL score after initial therapy and that after surgery.
No significant differences in patients' oral health-related QoL were observed between post-initial therapy and post-surgery intervals, although a tendency of surgery to determine an improvement in QoL was observed when compared with post-initial treatment.
Journal Of Clinical Periodontology 10/2011; 38(12):1115-21. · 3.69 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the antibacterial activity of povidone-iodine (PVP-I) on an artificial dual species biofilm of periodontal pathogens.
Porphyromonas gingivalis or Fusobacterium nucleatum grown in broth culture was inoculated on polycarbonate membrane (PCM) tissue culture inserts. After incubation for 72 h, PVP-I solutions were applied to the biofilm for the time period ranging from 0.5 to 5 min. After addition of a deactivator, each PCM was removed and the biofilm on the PCM was serially diluted and plated on blood agar plates and cultured anaerobically for 7 days. Then viable bacteria were enumerated.
In the dual species biofilm model, F. nucleatum showed an approximately 200-fold increase in viable counts when compared with mono-microbial biofilm. In dual species biofilm, PVP-I with concentration equal to or greater than 2% was required to significantly reduce P. gingivalis and F. nucleatum. When the contact time of PVP-I was increased to 1 min or greater, no difference in antibacterial activity of PVP-I was observed in any concentration.
These results suggest that 30s application of 2% PVP-I would be effective in suppressing both P. gingivalis and F. nucleatum in dual-species biofilm, and this provides clinical implication for the control of subgingival biofilm.
Archives of oral biology 09/2011; 57(4):364-8. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pemphigus vulgaris is an autoimmune disease caused by IgG antibodies against desmoglein 3 (Dsg3). Previously, we isolated a pathogenic mAb against Dsg3, AK23 IgG, which induces a pemphigus vulgaris-like phenotype characterized by blister formation. In the present study, we generated a transgenic mouse expressing AK23 IgM to examine B-cell tolerance and the pathogenic role of IgM. Autoreactive transgenic B cells were found in the spleen and lymph nodes, whereas anti-Dsg3 AK23 IgM was detected in the cardiovascular circulation. The transgenic mice did not develop an obvious pemphigus vulgaris phenotype, however, even though an excess of AK23 IgM was passively transferred to neonatal mice. Similarly, when hybridoma cells producing AK23 IgM were inoculated into adult mice, no blistering was observed. Immunoelectron microscopy revealed IgM binding at the edges of desmosomes or interdesmosomal cell membranes, but not in the desmosome core, where AK23 IgG binding has been frequently detected. Furthermore, in an in vitro dissociation assay using cultured keratinocytes, AK23 IgG and AK23 IgM F(ab')(2) fragments, but not AK23 IgM, induced fragmentation of epidermal sheets. Together, these observations indicate that antibodies must gain access to Dsg3 integrated within desmosomes to induce the loss of keratinocyte cell-cell adhesion. These findings provide an important framework for improved understanding of B-cell tolerance and the pathophysiology of blister formation in pemphigus.
American Journal Of Pathology 06/2011; 179(2):795-806. · 4.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by the forced expression of defined transcription factors. Although most somatic cells are capable of acquiring pluripotency with minimal gene transduction, the poor efficiency of cell reprogramming and the uneven quality of iPS cells are still important problems. In particular, the choice of cell type most suitable for inducing high-quality iPS cells remains unclear.
Here, we generated iPS cells from PDGFRα+ Sca-1+ (PαS) adult mouse mesenchymal stem cells (MSCs) and PDGFRα⁻ Sca-1⁻ osteo-progenitors (OP cells), and compared the induction efficiency and quality of individual iPS clones. MSCs had a higher reprogramming efficiency compared with OP cells and Tail Tip Fibroblasts (TTFs). The iPS cells induced from MSCs by Oct3/4, Sox2, and Klf4 appeared to be the closest equivalent to ES cells by DNA microarray gene profile and germline-transmission efficiency.
Our findings suggest that a purified source of undifferentiated cells from adult tissue can produce high-quality iPS cells. In this context, prospectively enriched MSCs are a promising candidate for the efficient generation of high-quality iPS cells.
PLoS ONE 01/2011; 6(3):e17610. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Burkitt's lymphoma is a malignant lymphoma of high malignancy grade and accounts for less than 1% of all cases of malignant lymphoma. Patients with malignant lymphoma in the oral and maxillofacial region including Burkitt's lymphoma, frequently present with gingival swelling, or a tumor mass/ulcers as the initial symptoms. We present an extremely rare case with bilateral mental nerve paralysis as the initial symptom without not only regional tumor but also brain and nose-pharyngeal area. This report indicates that the unexplained oral abnormalities such as inferior alveolar nerve hypoesthesia must be considered, potentially prodromal symptoms of Burkitt's lymphoma.
Asian Journal of Oral and Maxillofacial Surgery 09/2010; 22(3):180–184.
[show abstract][hide abstract] ABSTRACT: It is becoming increasingly important for periodontists and dental hygienists to take a biopsychosocial approach to care when considering periodontal interventions. However, information on how patients perceive periodontitis and its treatment is limited. The purpose of the present study is to gain insight into the patient perception of oral health and the impact that periodontitis and treatment have on self-assessed quality of life (QoL).
This was a prospective, two-center, clinical study in Japan. Patients with periodontitis were assessed for their perceptions of oral health by using an instrument for oral health-related QoL (OHRQL) before and after initial periodontal therapy.
A total of 58 patients (mean age: 53.6 years; 23 male and 35 female) participated in the study and completed initial periodontal therapy. At baseline, 97% of the patients perceived that their oral health status impacted on their QoL in one or more ways. Pain, eating and chewing, and psychologic function were identified as compromised OHRQL domains. More than one-half of the patients rated their overall oral health as poor. Initial periodontal therapy, consisting mainly of oral hygiene instructions and scaling and root planing, significantly improved OHRQL scores (P = 0.0027). The effect size was calculated to be 0.51, indicating a moderate improvement. Compared with baseline, a significantly higher proportion of patients reported rarely or never having a problem regarding OHRQL domains such as pain (P = 0.0049) and eating and chewing (P = 0.0145) after treatment. No significant difference in the OHRQL improvement was found with respect to disease severity.
Periodontitis negatively affected QoL in this population of Japanese patients with periodontitis. Conventional non-surgical periodontal therapy has a potential to ameliorate patient perceptions of oral health.
Journal of Periodontology 03/2010; 81(7):1001-9. · 2.40 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) are defined as cells that undergo sustained in vitro growth and can give rise to multiple mesenchymal lineages. Because MSCs have only been isolated from tissue in culture, the equivalent cells have not been identified in vivo and little is known about their physiological roles or even their exact tissue location. In this study, we used phenotypic, morphological, and functional criteria to identify and prospectively isolate a subset of MSCs (PDGFRalpha+Sca-1+CD45-TER119-) from adult mouse bone marrow. Individual MSCs generated colonies at a high frequency and could differentiate into hematopoietic niche cells, osteoblasts, and adipocytes after in vivo transplantation. Naive MSCs resided in the perivascular region in a quiescent state. This study provides the useful method needed to identify MSCs as defined in vivo entities.
Journal of Experimental Medicine 10/2009; 206(11):2483-96. · 13.21 Impact Factor
[show abstract][hide abstract] ABSTRACT: Three types of eosin-derivatized gelatins (eosin-gelatins) with different molecular weights (M(w)) of ca. 15 kDa (low-molecular-weight eosin-gelatin, LEG), ca. 30 kDa (medium-molecular-weight eosin-gelatin, MEG), and ca. 95 kDa (high-molecular-weight eosin-gelatin, HEG) were prepared. All the eosin-gelatins except for HEG dissolved completely in water at 37 degrees C within several hours even at high concentrations of 35 or 40 wt % along with polyamine (poly(N,N-dimethylaminopropylacrylamide)) to produce photo-crosslinkable materials. The materials had appropriate viscosity for in situ molding at 37 degrees C and could be handled as a liquid at low temperatures of up to 25 degrees C. Upon photoirradiation for several tens of seconds, the materials were converted almost completely to hydrogels in the desired form with a microporous network structure by the radical coupling reaction. The mechanical strength of the produced hydrogels could be controlled by selecting a particular molecular weight or concentration of eosin-gelatins. The hydrogels obtained from LEG (40 wt %) or MEG (35 wt %) had elasticity similar to that of goat periodontal tissue. The handling of the photo-crosslinkable materials at room temperature and their photogelation ability were drastically improved by reducing the M(w) of eosin-gelatin. The potential usefulness of the photo-crosslinkable materials to periodontal regeneration has been discussed.
Journal of Biomedical Materials Research Part B Applied Biomaterials 06/2009; 91(1):329-36. · 2.31 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) are a heterogeneous subset of stromal stem cells isolated from many adult tissues. Previous studies reported that MSCs can differentiate to both mesodermal and neural lineages by a phenomenon referred to as ''dedifferentiation'' or ''transdifferentiation''. However, since MSCs have only been defined in vitro, much of their development in vivo is still unknown. Here, we prospectively identified MSCs in the bone marrow from adult transgenic mice encoding neural crest-specific P0-Cre/Floxed-EGFP and Wnt1-Cre/Floxed-EGFP. EGFP-positive MSCs formed spheres that expressed neural crest stem cell genes and differentiated into neurons, glial cells, and myofibroblasts. Interestingly, we observed MSCs both in the GFP(+) and GFP(-) fraction and found that there were no significant differences in the in vitro characteristics between these two populations. Our results suggest that MSCs in adult bone marrow have at least two developmental origins, one of which is the neural crest.
Biochemical and Biophysical Research Communications 02/2009; 379(4):1114-9. · 2.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: Invasion by Porphyromonas gingivalis has been proposed as a possible mechanism of pathogenesis in periodontal and cardiovascular diseases. Porphyromonas gingivalis have direct access to the systemic circulation and endothelium in periodontitis patients by transient bacteremia. Periodontitis can be described as one of the predominant polymicrobial infections of humans. In the present study, P. gingivalis strains were tested for their ability to invade a human gingival epithelial cell line (Ca9-22) and human aortic endothelial cells in coinfection with Fusobacterium nucleatum using antibiotic protection assays. Coinfection with F. nucleatum resulted in 2-20-fold increase in the invasion of host cells by P. gingivalis strains. The invasive abilities of P. gingivalis strains were significantly greater when incubated with a F. nucleatum clinical isolate (which possesses strong biofilm-forming ability), than when incubated with a F. nucleatum-type strain. In inhibition assays with metabolic inhibitors, a difference in inhibition profiles was observed between mono- and polymicrobial infections. Collectively, our results suggest that F. nucleatum facilitates invasion of host cells by P. gingivalis. Investigations of polymicrobial infection of host cells should improve our understanding of the role of P. gingivalis in periodontal infection and proatherogenic mechanisms.
[show abstract][hide abstract] ABSTRACT: The balance between osteoclast and osteoblast activity is central for maintaining the integrity of bone homeostasis. Here we show that mice lacking dendritic cell specific transmembrane protein (DC-STAMP), an essential molecule for osteoclast cell–cell fusion, exhibited impaired bone resorption and upregulation of bone formation by osteoblasts, which do not express DC-STAMP, which led to increased bone mass. On the contrary, DC-STAMP over-expressing transgenic (DC-STAMP-Tg) mice under the control of an actin promoter showed significantly accelerated cell–cell fusion of osteoclasts and bone resorption, with decreased osteoblastic activity and bone mass. Bone resorption and formation are known to be regulated in a coupled manner, whereas DC-STAMP regulates bone homeostasis in an un-coupled manner. Thus our results indicate that inhibition of a single molecule provides both decreased osteoclast activity and increased bone formation by osteoblasts, thereby increasing bone mass in an un-coupled and a tissue specific manner.
Biochemical and Biophysical Research Communications 12/2008; · 2.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: High-dose cytarabine is one of the major components of the conditioning regimen for hematopoietic stem cell transplantation (HSCT), and frequently causes severe oral mucositis. We have recently demonstrated that cytarabine is excreted into the saliva in patients receiving high-dose cytarabine, and proposed that it might locally and directly contribute to the development of oral mucositis. Therefore, this study was performed to assess whether removing the excreted cytarabine in the saliva by intensive mouth rinse during high-dose cytarabine infusion could reduce the incidence of oral mucositis. Fifteen patients with hematologic malignancies undergoing allogeneic HSCT who received total body irradiation (12 Gy) and high-dose cytarabine at a dose of 3 g/m(2) every 12 h for 4 days as a conditioning were evaluated. Patients were instructed to rinse their mouths using ice-cold water every 10 min, starting simultaneously with the 2-h cytarabine infusion and continuing up to 1 h after completion of each infusion. Oral mucositis was graded on a daily basis according to the National Cancer Institute, Common Toxicity Criteria. Thirty-five patients who previously underwent the same conditioning without mouth rinse served as controls. The incidence of Grades 2-3 and Grade 3 oral mucositis was significantly reduced in patients who performed mouth rinse as compared with the controls (40 vs. 80%, P = 0.009; 0 vs. 25. 7%, P = 0.02). In conclusion, mouth rinse during and shortly after high-dose cytarabine infusion could be an effective and inexpensive measure in reducing the incidence of moderate to severe oral mucositis caused by high-dose cytarabine. This finding strongly suggests the role of cytarabine excretion in the saliva in the development of cytarabine-associated oral mucositis.
International journal of hematology 11/2008; 88(5):583-7. · 1.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: Novel photocurable materials, comprised mixed aqueous solutions of photoreactive gelatin – gelatin partially derivatized with eosin – and polyamine, which is a polymer of N,N-dimethylaminopropylacrylamide, were designed. The materials had appropriate viscosity for shape formation at 37 °C. When photoirradiated with a clinically used visible light source, the materials were almost completely converted to hydrogels to fix their shape in the desired form within several tenths of a second. Cells that were seeded on the eosin–gelatin-coated surface showed good proliferation. Negligible cytotoxicity of eosin–gelatin was confirmed when culturing was performed in the presence of a large amount of eosin–gelatin. The developed photocurable materials could be converted to a hydrogel with desired physical property change by using a convenient curing procedure of photoirradiation at any desired time and in any shape with minimal cytotoxicity, which was appropriate for the application in periodontal tissue regeneration.
Journal of Photochemistry and Photobiology A: Chemistry. 01/2008;
[show abstract][hide abstract] ABSTRACT: A total of 8 strains of 6 bacterial species, Porphyromonas gingivalis ATCC33277 and TDC286, Actinobacillus actinomycetemcomitans ATCC29523 and JP2, Fusobacterium nucleatum No. 2, Tannerella forsythensis ATCC43937, Prevotella intermedia ATCC25611 and Streptococcus anginosus ATCC33397, were treated with povidone-iodine (PVP-I) gargle (PVP-I: 0.47 and 0.23% w/v) or chlorhexidine gluconate (CHG) gargle (CHG: 0.002% w/v) for 15, 30 or 60 s, after which they were inoculated into various media, cultured and counted for residual bacteria. At both concentrations, PVP-I gargle reduced the viable cell count of all 8 bacterial strains to below the measurable limit within 15 s. By contrast, there were more than 1,000 viable colonies 60 s following treatment with the CHG gargle. The results demonstrate that povidone-iodine gargle has rapid bactericidal activity against the causative bacteria of periodontal disease.