Characterization of side population (SP) cells in murine cochlear nucleus

CONCLUSION

We characterized side population (SP) cells in the cochlear nucleus (CN). Some genes of stem/progenitor markers in sorted SP cells were identified by microarray analysis and RT-PCR. Furthermore, some cells in the CN also demonstrated self-renewal and clonal expansion activities. These results suggest that tissue stem/ progenitor like cells would be identified and characterized as a slow cycling and immaturity in SP cells of CN.

OBJECTIVES

SP cells were sorted and characterized as regards their activity in the CN in order to identify the tissue progenitor/stem cells in the auditory nervous system.

METHODS

Bromodeoxyuridine (BrdU)-injected mice were prepared and the long-term BrdU-retaining cells were detected by flow cytometry. Gene expression of SP and MP cells was analyzed by microarray analysis and RT-PCR. SP cells were cultured in conditioned medium to expand stem/progenitor cells in vitro and to estimate the spheroid-forming activity of stem cells.

RESULTS

In all, 1% of cells in the CN were detected as BrdU-positive. SP cells were detected at a frequency of 4.4% and expressed stem/progenitor markers, Abcb1b, Abcg2, Sca1, Notch1, Notch4, Hes1, and Jag1 in microarray analysis. Expression of Abcb1b, Abcg2, Sca1,Oct3/4, and Sox2 as determined by RT-PCR was supported by the microarray data. CN cells also had sphere-forming activity in young mice, but this activity was decreased by aging.

Efficacy of Fungiflora Y staining for the diagnosis of oral erythematous candidiasis

OBJECTIVE

The purpose of this study was to investigate the efficacy of Fungiflora Y staining (fluorescent stain) for the diagnosis of erythematous candidiasis.

SUBJECTS AND METHODS

This study enrolled 48 patients who were diagnosed with erythematous candidiasis and who underwent fungal culture and microscopic examination of a smear specimen stained with CytoQuick (modification of the Giemsa stain) and Fungiflora Y. Fungiflora Y staining was observed using a portable fluorescent microscope (CyScope(®)). The sensitivity, specificity and positive and negative predictive values were calculated using fungal culture as the gold standard test. Accuracy was calculated, and the difference between the CytoQuick and Fungiflora Y groups was examined using contingency tables and the chi-square test.

RESULTS

The sensitivity and specificity of the CytoQuick stain was 0.51 and 0.91, respectively; the positive predictive value was 0.95, and the negative predictive value was 0.36. The sensitivity and specificity of the Fungiflora Y stain was 0.84 and 1.0, respectively; the positive predictive value was 1.00, and the negative predictive value was 0.65. The accuracy of Fungiflora Y (0.88) was superior to that of CytoQuick (0.60) (p = 0.0052).

CONCLUSIONS

Microscopic examinations of smear specimens using a combination of Fungiflora Y staining and the CyScope(®) portable fluorescent microscope was found to be useful for the diagnosis of oral erythematous candidiasis.

Characterization of cultivated murine lacrimal gland epithelial cells

PURPOSE

To date, mouse lacrimal gland epithelial cells have been cultured successfully but only in cases involving newborn mouse lacrimal glands. In this work, we attempted to cultivate and characterize adult mouse lacrimal gland epithelial cells.

METHODS

Lacrimal glands were removed from newborn mice (C57B/6) and isolated lacrimal gland epithelial cells were seeded onto tissue culture treated or low adherent culture dishes in Cnt-07 culture medium with or without cholera toxin. Cultivated cells were characterized by immunostaining with pan-cytokeratin, α-smooth muscle actin, and lactoferrin antibodies. Lacrimal gland cells from 7-week-old green fluorescent protein (GFP) and non-GFP (C57B/6) mice were mixed and seeded onto uncoated dishes to assess sphere-forming efficiency. Cells were also seeded onto 3T3 cell feeder layers to assess colony forming efficiency.

RESULTS

Lacrimal gland epithelial cells were selectively cultured with cholera toxin, and cell type was verified by pan-cytokeratin and α-smooth muscle actin immunostaining. Sphere formation from single cells of adult mice was observed using specific medium and low adherent culture dishes. These cells could also undergo colony formation on 3T3 feeder cells.

CONCLUSIONS

Adult mouse lacrimal gland epithelial cells were successfully cultivated in cholera toxin-containing medium, and were observed to form spheres from single cells.

Aryl hydrocarbon receptor-mediated induction of EBV reactivation as a risk factor for Sjögren's syndrome

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates a variety of biological effects by binding to environmental pollutants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin). Although numerous animal studies have demonstrated the harmful effects of dioxins, it remains controversial whether dioxins pose a risk to human health. Enhanced lytic replication of EBV is a risk factor for the development of autoimmune diseases and cancers. This study evaluated the possibility that ligand-activated AhR reactivates EBV. EBV reactivation and AhR transactivation were evaluated with luciferase assays. Saliva samples were collected from 19 patients with primary Sjögren's syndrome (SS). Control saliva samples were obtained from 10 healthy individuals and nine patients with severe dry mouth. TCDD enhanced BZLF1 transcription, which mediates the switch from the latent to the lytic form of EBV infection in EBV-positive B cell lines and in a salivary gland epithelial cell line. Moreover, TCDD-induced increases in BZLF1 mRNA and EBV genomic DNA levels were confirmed in the B cell lines. Saliva from SS patients activated the transcription of both CYP1A1 and BZLF1. Additionally, there was a positive correlation between CYP1A1 and BZLF1 promoter activities. AhR ligands elicited the reactivation of EBV in activated B cells and salivary epithelial cells, and these ligands are involved in SS. Our findings reveal novel aspects of the biological effects of dioxin and the AhR-dependent pathogenesis of autoimmune diseases.

Phenotypic changes associated with exogenous expression of p16INK4a in human glioma cells

The tumor suppressor p16/CDKN2A/INK4a gene is frequently mutated, mostly by homozygous deletions in high-grade gliomas. Although the p16 protein suppresses cell proliferation primarily through inhibition of cell-cycle progression at the G1 phase, other phenotypic changes in glioma cells associated with p16INK4a alterations have not been fully described. To determine the roles of p16 alterations in glioma formation, we have established ecdysone-driven inducible p16 expression in the human glioblastoma cell line CL-4, which were derived from p16-null U87MG cells. Here we show that exogenous p16 expression in CL-4 cells results in morphological changes, with large and flattened cytoplasm, which are associated with increased formation of cytoplasmic actin-stress fibers and vinculin accumulation in the focal adhesion contacts. Adhesion of CL-4 cells to extracellular matrix proteins, such as laminin, fibronectin, and type IV collagen, significantly increased upon exogenous p16 expression, which correlated with increased expression of integrin alpha5 and alphav. Expression of a small GTP-binding protein, Rac, also decreased. Following epidermal growth factor stimulation, phosphorylation of MAP kinases ERK1 and 2 and induction of an early immediate gene product, c-Fos, were significantly reduced in CL-4 cells with p16 expression. These results suggest that the tumor suppressor p16 may exert its antitumor effects through modulation of multiple aspects of glioblastoma phenotypes, including proliferation, invasiveness, and responsiveness to extracellular growth stimuli.

The periodontal pathogen Porphyromonas gingivalis induces the Epstein-Barr virus lytic switch transactivator ZEBRA by histone modification

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that usually results in latent infection of B cells. The EBV BZLF1 gene product ZEBRA is a master regulator of the transition from latency to the lytic replication cycle. In the latent state, hypoacetylation of histone proteins in the BZLF1 promoter by histone deacetylases (HDACs) is primarily involved in maintaining EBV latency. Although the mechanism that regulates the switch between latency and lytic replication has been a central research focus in EBV infection, the causal link between HDAC inhibition and the disruption of viral latency is not well understood. Periodontal disease is a complex chronic inflammatory disease caused by subgingival infection with oral anaerobic bacteria, typically Porphyromonas gingivalis. Periodontal disease occurs worldwide and is among the most prevalent microbial diseases in humans. In this study, we examined the biological effect of P. gingivalis infection on EBV reactivation and found that P. gingivalis induced expression of ZEBRA. This activity was associated with supernatant from bacterial culture, but not with other bacterial components such as lipopolysaccharide or fimbriae. We demonstrated that culture supernatant from P. gingivalis, which contained high concentrations of butyric acid, inhibited HDACs, thus increasing histone acetylation and the transcriptional activity of the BZLF1 gene. Chromatin immunoprecipitation assays revealed that HDACs were present in the BZLF1 promoter during latent state and that they were dissociated from the promoter concomitantly with the association of acetylated histone H3, upon stimulation by culture supernatant from P. gingivalis. Thus, P. gingivalis induced EBV reactivation via chromatin modification, and butyric acid-a bacterial metabolite-was responsible for this effect. These findings suggest that periodontal disease is a risk factor for EBV reactivation in infected individuals and might therefore contribute to progression of EBV-related diseases.

Development and growth of adenomatoid odontogenic tumor related to formation and eruption of teeth

The number of published cases of adenomatoid odontogenic tumor (AOT) has steadily increased, and about half were reported in Asian populations. Although the clinicopathologic profile of AOT has been extensively reported, factual knowledge of its pathogenesis is rudimentary at best, and there is controversy as to precisely which odontogenic epithelium it arises from. AOT is a successional tooth-associated lesion which develops during the mixed dentition. The permanent successor differs from its deciduous predecessor in that it has an eruptive pathway from the dental follicle to the gingiva, the gubernaculum dentis. With this background in mind, the present review focuses mainly on the early development of AOT. We successfully demonstrated a close spatial relationship between AOT and the gubernaculum dentis in a typical case. From further observations of the same AOT in which an enclosed permanent canine showed enamel hypoplasia, it is possible to pinpoint areas around the crown of a developing successional tooth in continuity with the gubernaculum dentis as starting points. In addition, we discuss the unifying histogenetic concept of three clinical variants, namely, pericoronal (follicular), extracoronal (extrafollicular), (see Article note) and peripheral.

Effects of coenzyme Q10 on salivary secretion

OBJECTIVES

Dry mouth is a condition associated with reduced salivary secretion and is thought to be related to aging. This study was conducted to test whether reduced (ubiquinol) or oxidized (ubiquinone) forms of CoQ10 affect salivary secretion and salivary CoQ10 content before and after treatment.

DESIGN AND METHODS

Sixty-six patients were given either ubiquinol or ubiquinone orally at a dosage of 100 mg/day, or a placebo for 1 month, and salivary secretion and salivary CoQ10 content were analyzed before and after treatment.

RESULTS

Both parameters were significantly improved following treatment with either form of CoQ10, suggesting the effectiveness of CoQ10 in attenuating dry mouth symptoms.

CONCLUSION

CoQ10 was locally detected in salivary glands, suggesting that orally administered CoQ10 was transported to the salivary glands via the blood stream and exerted its activity, improving salivary secretion.

Expression and cellular localizaion of melatonin-synthesizing enzymes in rat and human salivary glands

Melatonin, discovered in 1958, is secreted by the pineal gland primarily during the night. Its secretion is controlled by the light/dark cycle of the environment. Melatonin is also produced in and secreted by various extrapineal organs, tissues and cells and its synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT) is expressed in various extrapineal organs, tissues and cells. Recently, it was reported that melatonin is present in saliva, but it is not certain where melatonin was synthesized and whether it was secreted into saliva and what function it may have in saliva. The present study was performed to investigate where melatonin was synthesized and whether it was secreted by salivary glands into saliva. We performed immunohistochemical analysis of the expression of AANAT in rat parotid, submandibular and sublingual glands and the expression of both AANAT and hydroxyindole-O-methyltransferase (HIOMT) in human submandibular glands. We evaluated the expression of AANAT and HIOMT mRNA in rat submandibular glands by quantitative reverse transcription-polymerase chain reaction. As a result, we observed expression of AANAT in epithelial cells of striated ducts in rat salivary glands and expression of AANAT, HIOMT and melatonin in epithelial cells of striated ducts in human submandibular glands. In addition, we also confirmed the expression of the most potent melatonin receptor, melatonin 1a receptor, in rat buccal mucosa. Our findings suggest that melatonin might be produced and secreted by salivary glands directly into saliva and that it might play some physiological role in the oral cavity.

Evaluation of therapeutic effects of astaxanthin on impairments in salivary secretion

The involvement of reactive oxygen species (ROS) in the pathophysiology of Sjögren's syndrome (SS), an autoimmune disorder, and irradiation-induced impairments in salivary secretion has been reported. Meanwhile, the strong antioxidant astaxanthin (Ast) has been suggested to have therapeutic effects on various diseases. In the present study, we examined the ROS scavenging capacity of Ast using a human salivary gland epithelial cell line (HSY) and investigated the effects of Ast on salivary secretion in a mouse model of irradiation-induced salivary gland dysfunction. Furthermore, we performed a clinical study of Ast in six SS patients and six normal individuals, quantifying the volume of saliva secretion and the level of oxidative stress markers in the saliva. Ast partially suppressed hydrogen peroxide-induced ROS in HSY cells. The mouse model demonstrated that the pre-administration of Ast resulted in the suppression of irradiation-induced hyposalivation. Furthermore, the administration of Ast appeared to increase salivary output in both the SS and normal groups. The level of oxidative stress marker, hexanoyl-lysine, in the saliva was reduced after Ast intake. These results suggest that Ast might act as an ROS scavenger, providing benefits to SS patients with impaired salivary secretion.

Intraosseous ameloblastoma with a prominent extraosseous component: pitfalls in diagnosis

For many years, gingival tumors of what appear to be peripherally located intraosseous ameloblastoma (IA) arising from the alveolar bone surface have often been confused with peripheral ameloblastoma (PA) causing resorption of the underlying bone. We analyzed a series of five cases of ameloblastoma that demonstrated a combined PA and IA architecture. The tumor commonly involved the anterior-premolar area, mostly in the maxilla and mainly in middle-aged men. The clinical presentation was an exophytic gingival mass inferior to which was a small bone defect. The predominant extraosseous component showed a papillary gross surface, reflecting the histologic proof of fusion between the submucosal tumor and the surface epithelium. In addition to the PA-like growth pattern, common to all was the presence of neoplastic destruction of the alveolar process, corresponding to an associated radiolucent lesion. This restrained component was acceptable as IA. In two cases, recurrence was observed deep in the alveolar bone with no involvement of the gingiva. These tumors appear to be IA that arose from the marginal alveolar bone and grew preferentially in the gingiva, forming a PA-like appearance. From diagnostic, therapeutic and prognostic points of view, this type of IA should not be confused with PA.