Journal of Oral Biosciences最新文献

Objectives: The oral microbiome plays an important role in the development and progression of periodontal disease. The purpose of this study was to compare microbial profiles of oral cavities in good health, with gingivitis, and in a state of periodontitis, and to identify novel pathogens involved in periodontal diseases.

Methods: One hundred and two participants, including 33 healthy controls, 41 patients with gingivitis, and 28 patients with periodontitis, were included in this cross-sectional study. Salivary oral microbiomes were investigated using 16S rRNA metagenomic sequencing, and the microbial profiles of each group were compared using age- and sex-adjusted general linear models.

Results: The abundance of amplicon sequence variants and Chao1 diversity were significantly elevated in the gingivitis and periodontitis groups relative to healthy controls (p = 0.046). Based on linear discriminant analysis (LDA) scores (>2), Tenericutes, Mollicutes, Mycoplasmatales, Mycoplasmataceae, Mycoplasma, Bacteroidaceae, and Phocaeicola were significantly enriched in the gingivitis group, and Synergistetes, Synergistia, Synergistales, Synergistaceae, Fretibacterium, Sinanaerobacter, and Filifactor were enriched in the periodontitis group. The relative abundances of Fretibacterium fastidiosum, Sinanaerobacter chloroacetimidivorans, and Filifactor alocis (q = 0.008, all bacteria) were highest in the periodontitis group and lowest in the control group. The relative abundance of Treponema denticola was significantly elevated in the periodontitis group compared to the other two groups (q = 0.024).

Conclusions: Oral microbiomes differed between groups. T. denticola, F. fastidiosum, S. chloroacetimidivorans and F. alocis were significantly more abundant in the periodontitis group than in the control group. Additionally, the abundance of T. denticola and F. fastidiosum in the periodontitis group was significantly different from that in the gingivitis group.

Objectives: This study aimed to investigate the impact of organic, conventional, and stingless honey on gummy candies, focusing on the effect of the cariogenic bacterium, Streptococcus mutans UA159, and total bacterial count in saliva from adolescents.

Methods: Antimicrobial compounds in three honey samples were identified, and the minimum inhibitory concentration against S. mutans UA159 was determined. The antibacterial activities of the three honey candy formulations were determined against S. mutans UA159 in artificial saliva and total bacteria in saliva collected from adolescents. The sensory acceptance of the candy formulations by children, adolescents, and adults was investigated.

Results: Candies prepared using conventional honey showed the highest antibacterial activity against S. mutans UA159 in vitro and total bacteria in human saliva. This effect was attributed to the higher levels of quercetin, myricetin, caffeine, and hydrogen peroxide in conventional honey.

Conclusions: Nicotinic, ferulic, and p-coumaric acids found in honey had low antibacterial activity against oral bacteria. Quercetin, myricetin, caffeine, and hydrogen peroxide are the main anticariogenic compounds in honey and exert antibacterial effects on adolescent saliva, despite added to candies. However, organic production does not necessarily improve the biological properties of honey. All candies were equally liked by sensory assessors (acceptance > 70%), facilitating the selection of honey with higher biological activities to formulate functional candies.

Objectives: Oral submucous fibrosis (OSF) is a chronic, progressive, and potentially malignant disease of the oral cavity. A previous study by our team found that the aberrant expression of tRNA-derived small RNA (tsRNA) was involved in the development of OSF, with tiRNA-Val-CAC-002 showing the most significant difference. This study aimed to investigate the effect of tiRNA-Val-CAC-002 on fibroblast activation and its underlying mechanisms, elucidate the pathogenesis of OSF, and explore new effective targets for OSF prevention and treatment.

Methods: RT-PCR was used to detect tiRNA-Val-CAC-002 expression in OSF and arecoline-treated fibroblasts. Western blotting, MDC staining, and transmission electron microscopy validated the effects of arecoline and 002 on fibroblast autophagy. Western blotting was used to explore the signaling pathways related to tiRNA-Val-CAC-002 in OSF.

Results: Arecoline promotes fibroblast (FB) activation by upregulating tiRNA-Val-CAC-002. Arecoline stimulation and tiRNA-Val-CAC-002 overexpression activated fibroblasts by promoting autophagy. tiRNA-Val-CAC-002 regulates PI3K/AKT by mediating ITGB3 expression.

Conclusions: Arecoline upregulates tiRNA-Val-CAC-002 expression in fibroblasts. Moreover, tiRNA-Val-CAC-002 may activate the autophagy of fibroblasts in OSF by ITGB3/PI3K/AKT pathway regulation, promoting the expression of collagen fibers.

Background: Fibrotic responses in the gingiva are characterized by their hyperproliferative nature instead of scar tissue formation. Clinically, these conditions appear as "gingival overgrowth" (GO), which can be of drug-induced or genetic origin. Despite surgical removal, GO can recur. Therefore, non-invasive methods of treating GO are required. In other fibrotic systems, the matricellular protein CCN2 represents a potential therapeutic target. However, CCN2 has been relatively understudied in the context of GO.

Highlight: Herein, we describe what is known regarding CCN2 expression in GO and gingival fibroblasts. Specifically, CCN2 is induced by agents that promote fibrogenesis in the oral cavity, such as transforming growth factor-β, and drugs that promote GO, such as cyclosporine, nifedipine, and phenytoin.

Conclusion: Although little is known regarding the possible function of CCN2 in GO, given the correlation between CCN2 expression and GO recurrence, we hope that this review will inspire further research on this topic.

Objectives: Slightly acidic electrolyzed water (SAEW) is produced by electrolyzing 2-6% diluted hydrochloric acid in a membrane-less chamber, resulting in 5.0-6.5 pH, and can be applied to various foods as a disinfectant. Although SAEW has shown to have bactericidal activity, the details of its anti-fungal effects towards Candida species remain unknown. Therefore, we examined the fungicidal effects of SAEW on Candida spp. and biofilms on acrylic resins.

Methods: The fungicidal effects of SAEW on Candida spp. at different reaction times and total numbers of colonies in culture plates were examined. Subsequently, SAEW was added to Candida spp. biofilms formed on polystyrene plates, and adenosine triphosphate (ATP) in SAEW was measured to examine its fungicidal effects towards Candida spp. biofilms. The fungicidal effect of SAEW on Candida spp. biofilms was determined by counting the number of colonies on the acrylic resin after adding SAEW.

Results: SAEW completely killing activity within 1 min with the tested Candida spp.. C. albicans and C. glabrata ATP were increased 5 min after adding SAEW compared with the controls, suggesting the removal of biofilm. Of the C. albicans on acrylic resin, > 99.9%were killed by SAEW compared to their levels in deionized distilled water (DW) (76.2x10²/mL and 43.3x10²/mL, respectively). Similarly, 93.1% of C. glabrata were killed by SAEW compared to DW (159.3x102/mL).

Conclusions: SAEW may be useful in preventing oral candidiasis as part of oral care.

Objectives: Bone graft materials commonly used for maxillary sinus floor augmentation (MSFA), including hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), are mostly granular and have poor handleability. HAp/collagen composite material (HAp/Col) and β-tricalcium phosphate (β-TCP)/poly(L-lactide-co-glycolide) (PLGA) have shown promise but their application in MSFA as bone graft materials remains unclear. Here, we investigated the bone-forming behavior of HAp/Col and β-TCP/PLGA in an MSFA rabbit model.

Methods: Male Japanese white rabbits were used. HAP/Col or β-TCP/PLGA was randomly applied to the MSFA model. The specimens were harvested at 4 weeks (W), 8W, 16W, and 24W after surgery, and the augmented regions were evaluated using micro-computed tomography and histological analyses.

Results: The graft materials were retained up to 16W in the HAp/Col group and 24W in the β-TCP/PLGA group. The augmented volume detected in the HAp/Col group at 4W was substantially reduced at subsequent time points. However, in the β-TCP/PLGA group, the volume observed at 4W was maintained up to 24W. In the HAp/Col group, the bone mineral content (BMC) at 4W was significantly lower than that at 8W (p=0.03716), and this elevated BMC was significantly decreased at 16W (p=0.00185) and 24W (p=0.00236). In the β-TCP/PLGA group, the BMC tended to increase from 4W to 16W and then decreased.

Conclusions: Both HAp/Col and β-TCP/PLGA are useful for MSFA because of their ability to form new bone and good handleability. The appropriate graft material should be selected depending on the application needs while understanding the properties of the newly formed bone.

Objectives: Secretory granules produced by salivary acinar cells accumulate if secretory stimulation is suppressed. Aged and deteriorated secretory granules can cause tissue damage because of abnormal secretion and/or intracellular leakage. To elucidate the deterioration process, we characterized the changes in the stimulus responsiveness of secretory granules using HaloTag technology.

Methods: We established a system in which HaloTag-fused cystatin D, a salivary protein, was transported to the secretory granules of rat parotid acinar cells in primary culture. HaloTags can be labeled with cell-permeable ligands conjugated to fluorescent dyes in living cells. To observe the new and old secretory granules, the cells were labeled with two HaloTag ligands conjugated to different fluorescent dyes at different times. We measured the secretion rates of newly synthesized and old HaloTag-fused proteins in the absence and presence of isoproterenol, a β-adrenergic agonist, at 3 and 6 h after initial labeling.

Results: Sequential labeling of HaloTag-fused proteins with two different dyes enabled the discrimination between new and old secretory granules. The secretory responsiveness of the proteins synthesized within 3 h to isoproterenol was higher than that of proteins synthesized earlier. However, there was no significant difference in the responsiveness between the new and old proteins at 6 h after initial labeling.

Conclusion: New secretory granules have a higher sensitivity to stimulants than older ones and that their response declines over time.

Background: Apoptosis was initially identified through transmission electron microscopy. Subsequent advances in morphological techniques for apoptosis detection have revealed its involvement in multiple pathological conditions in various tissues. This review summarizes previous experimental studies on apoptotic cell death during regressive changes in the salivary glands, with a focus on morphological observations.

Highlight: Obstructive sialadenitis is histologically characterized by acinar cell loss and increased number of duct cells. Although acinar cells were previously believed to dedifferentiate into duct cells, there is evidence that they are eliminated by apoptosis. Animals fed a soft diet exhibited parotid gland atrophy, in which acinar cells decreased in size and disappeared because of apoptosis. Age-related changes in the salivary glands involved a reduced number of acinar cell through apoptosis. Additionally, apoptotic acinar cell death occurs in other pathological conditions, including the regression of hypertrophic and irradiated salivary glands.

Conclusion: Apoptosis often eliminates acinar cells during atrophic alterations in the salivary glands. Unlike necrosis, apoptosis is an active form of cell death, thereby helping prevent the complete destruction of the salivary glands. However, the contribution of apoptosis to regressive changes in the salivary glands remains unclear and warrants further investigation.

Background: The mandible provides valuable insights into its biological identity. However, the existence of several terminologies for mandibular measurements and inconsistent language can lead to misinterpretation, confusion, and miscommunication.

Highlight: A standardised set of anatomical points, planes, and measurements would assist with these issues and ensure reproducibility and comparability.

Conclusion: The proposed coding system offers a comprehensive approach for professionals and researchers in dentistry, archaeology, and anthropology.

Objectives: The receptor tyrosine kinase Kit is expressed in cells derived from the trunk neural crest (NC), such as melanocytes; however, its role in cranial NC cell development is not fully understood.

Methods: We investigated the effects of the heterozygous loss of Kit in NC cells during embryonic development by mating Kit^2lox/+ mice with Wnt1-Cre mice to produce Wnt1-Cre; Kit^2lox/+ embryos. In addition, Wnt1-Cre mice were mated with Rosa26R-yellow fluorescent protein (YFP) mice to visualize the tissue regions expressing Cre recombinase. Histological studies of the craniofacial regions of these mice were performed using samples from embryonic day (E) 12.5 and postnatal day (P) 1. Cellular apoptosis and proliferation were both analyzed through the immunostaining of tissue sections collected on E13.5 and E14.5 using anti-cleaved caspase 3 (CC3) to detect apoptosis and anti-Ki67 to detect proliferation. Cells from YFP-positive tissue regions of the facial areas of Wnt1-Cre; Kit^+/+; Rosa26R-YFP embryos and Wnt1-Cre; Kit^2lox/+; Rosa26R-YFP embryos collected on E12.5 and E15.5 were cultured and evaluated for cell proliferation.

Results: Compared with control littermates, Wnt1-Cre; Kit^2lox/+ embryos exhibited midline cleft lip and bifid nose deformities. Substantial early (P1) postnatal lethality was observed in Wnt1-Cre; Kit^2lox/+ mice, with none surviving to 3 weeks of age. YFP-positive cells from the maxillary regions of Wnt1-Cre; Kit^2lox/+; Rosa26R-YFP embryos exhibited defective cell growth and self-renewal in vitro.

Conclusion: Conditional heterozygous loss of Kit in Wnt1-Cre; Kit^2lox/+ embryos is associated with craniofacial dysplasia and exhibit defective NC development in vitro and in vivo.