Salivary Proteome and Intact N-Glycopeptides Analysis Reveal Specific Signatures in Periodontitis.

Periodontitis is a prevalent oral inflammatory disease that can result in tooth loss and is closely linked to type 2 diabetes (T2D). In this study, we analyzed the salivary proteome and intact N-glycopeptides (IGPs) of individuals with mild-moderate, severe, aggressive periodontitis, and periodontitis with T2D, including those treated with antidiabetic drugs, to identify specific signatures associated with the disease. Our results revealed that salivary proteins and glycoproteins were altered in all periodontitis groups (PRIDE ID: 1-20230612-72345), with fucose- and sialic acid-containing N-glycans showing the greatest increase. Additionally, differentially expressed proteins were classified into 9 clusters, including those that were increased in all periodontitis groups and those that were only altered in certain types of periodontitis. Interestingly, treatment with antidiabetic drugs reversed many of the changes observed in the salivary proteome and IGPs in T2D-related periodontitis, suggesting a potential therapeutic approach for managing periodontitis in patients with T2D. Consistent with MS/MS results, the expression of salivary IGHA2 and Fucα1-3/6GlcNAc (AAL) was significantly increased in MP. These findings provide new insights into the pathogenesis of periodontitis and highlight the potential of salivary biomarkers for diagnosis, prognosis, and monitoring of disease progression and treatment response.

GroEL triggers NLRP3 inflammasome activation through the TLR/NF-κB p-p65 axis in human periodontal ligament stem cells.

The interaction between bacteria and the host plays a vital role in the initiation and progression of systemic diseases, including gastrointestinal and oral diseases, due to the secretion of various virulence factors from these pathogens. GroEL, a potent virulence factor secreted by multiple oral pathogenic bacteria, is implicated in the damage of gingival epithelium, periodontal ligament, alveolar bone and other peripheral tissues. However, the underlying biomechanism is still largely unknown. In the present study, we verify that GroEL can trigger the activation of NLRP3 inflammasome and its downstream effector molecules, IL-1ß and IL-18, in human periodontal ligament stem cells (hPDLSCs) and resultantly induce high activation of gelatinases (MMP-2 and MMP-9) to promote the degradation of extracellular matrix (ECM). GroEL-mediated activation of the NLRP3 inflammasome requires the participation of Toll-like receptors (TLR2 and TLR4). High upregulation of TLR2 and TLR4 induces the enhancement of NF-κB (p-p65) signaling and promotes its nuclear accumulation, thus activating the NLRP3 inflammasome. These results are verified in a rat model with direct injection of GroEL. Collectively, this study provides insight into the role of virulence factors in bacteria-induced host immune response and may also provide a new clue for the prevention of periodontitis.

A cascading learning method with SegFormer for radiographic measurement of periodontal bone loss.

OBJECTIVE: Marginal alveolar bone loss is one of the key features of periodontitis and can be observed via panoramic radiographs. This study aimed to establish a cascading learning method with deep learning (DL) for precise radiographic bone loss (RBL) measurements at specific tooth positions. MATERIALS AND METHODS: Through the design of two tasks for tooth position recognition and tooth semantic segmentation using the SegFormer model, specific tooth's crown, intrabony portion, and suprabony portion of the roots were obtained. The RBL was subsequently measured by length through these three areas using the principal component analysis (PCA) principal axis. RESULTS: The average intersection over union (IoU) for the tooth position recognition task was 0.8906, with an F1-score of 0.9338. The average IoU for the tooth semantic segmentation task was 0.8465, with an F1-score of 0.9138. When the two tasks were combined, the average IoU was 0.7889, with an F1-score of 0.8674. The correlation coefficient between the RBL prediction results based on the PCA principal axis and the clinicians' measurements exceeded 0.85. Compared to those of the other two methods, the average precision of the predicted RBL was 0.7722, the average sensitivity was 0.7416, and the average F1-score was 0.7444. CONCLUSIONS: The method for predicting RBL using DL and PCA produced promising results, offering rapid and reliable auxiliary information for future periodontal disease diagnosis. CLINICAL RELEVANCE: Precise RBL measurements are important for periodontal diagnosis. The proposed RBL-SF can measure RBL at specific tooth positions and assign the bone loss stage. The ability of the RBL-SF to measure RBL at specific tooth positions can guide clinicians to a certain extent in the accurate diagnosis of periodontitis.

Characterization and application of in situ curcumin/ZNP hydrogels for periodontitis treatment.

BACKGROUND: Periodontitis is a chronic inflammatory disease that occurs in tooth-supporting tissues. Controlling inflammation and alleviating periodontal tissue destruction are key factors in periodontal therapy. This study aimed to develop an in situ curcumin/zinc oxide (Cur/ZNP) hydrogel and investigate its characteristics and effectiveness in the treatment of periodontitis. METHODS: Antibacterial activity and cytotoxicity assays were performed in vitro. To evaluate the effect of the in situ Cur/ZNP hydrogel on periodontitis in vivo, an experimental periodontitis model was established in Sprague‒Dawley rats via silk ligature and inoculation of the maxillary first molar with Porphyromonas gingivalis. After one month of in situ treatment with the hydrogel, we examined the transcriptional responses of the gingiva to the Cur/ZNP hydrogel treatment and detected the alveolar bone level as well as the expression of osteocalcin (OCN) and osteoprotegerin (OPG) in the periodontal tissues of the rats. RESULTS: Cur/ZNPs had synergistic inhibitory effects on P. gingivalis and good biocompatibility. RNA sequencing of the gingiva showed that immune effector process-related genes were significantly induced by experimental periodontitis. Carcinoembryonic antigen-related cell adhesion molecule 1 (Ceacam1), which is involved in the negative regulation of bone resorption, was differentially regulated by the Cur/ZNP hydrogel but not by the Cur hydrogel or ZNP hydrogel. The Cur/ZNP hydrogel also had a stronger protective effect on alveolar bone resorption than both the Cur hydrogel and the ZNP hydrogel. CONCLUSION: The Cur/ZNP hydrogel effectively inhibited periodontal pathogenic bacteria and alleviated alveolar bone destruction while exhibiting favorable biocompatibility.

A bacterial tyrosine phosphatase modulates cell proliferation through targeting RGCC.

Tyrosine phosphatases are often weaponized by bacteria colonizing mucosal barriers to manipulate host cell signal transduction pathways. Porphyromonas gingivalis is a periodontal pathogen and emerging oncopathogen which interferes with gingival epithelial cell proliferation and migration, and induces a partial epithelial mesenchymal transition. P. gingivalis produces two tyrosine phosphatases, and we show here that the low molecular weight tyrosine phosphatase, Ltp1, is secreted within gingival epithelial cells and translocates to the nucleus. An ltp1 mutant of P. gingivalis showed a diminished ability to induce epithelial cell migration and proliferation. Ltp1 was also required for the transcriptional upregulation of Regulator of Growth and Cell Cycle (RGCC), one of the most differentially expressed genes in epithelial cells resulting from P. gingivalis infection. A phosphoarray and siRNA showed that P. gingivalis controlled RGCC expression through Akt, which was activated by phosphorylation on S473. Akt activation is opposed by PTEN, and P. gingivalis decreased the amount of PTEN in epithelial cells. Ectopically expressed Ltp1 bound to PTEN, and reduced phosphorylation of PTEN at Y336 which controls proteasomal degradation. Ltp-1 induced loss of PTEN stability was prevented by chemical inhibition of the proteasome. Knockdown of RGCC suppressed upregulation of Zeb2 and mesenchymal markers by P. gingivalis. RGCC inhibition was also accompanied by a reduction in production of the proinflammatory cytokine IL-6 in response to P. gingivalis. Elevated IL-6 levels can contribute to periodontal destruction, and the ltp1 mutant of P. gingivalis incited less bone loss compared to the parental strain in a murine model of periodontal disease. These results show that P. gingivalis can deliver Ltp1 within gingival epithelial cells, and establish PTEN as the target for Ltp1 phosphatase activity. Disruption of the Akt1/RGCC signaling axis by Ltp1 facilitates P. gingivalis-induced increases in epithelial cell migration, proliferation, EMT and inflammatory cytokine production.

Circular RNA hsa_circ_0084054 promotes the progression of periodontitis with diabetes via the miR-508-3p/PTEN axis.

BACKGROUND AND OBJECTIVE: Diabetes is an important risk factor for periodontitis, and circular RNA (circRNA) may play an important role in aggravating inflammation and accelerating disease progression by regulating miRNA/mRNA. This study aimed to investigate the role and mechanism of the hsa_circ_0084054/miR-508-3p/PTEN axis in the progression of periodontitis with diabetes. METHODS: First, circRNA sequencing was used to screen the differentially expressed circRNAs of periodontal ligament cells (PDLCs) treated with high glucose and/or Porphyromonas gingivalis lipopolysaccharide (LPS) in vitro, and the overtly differentially expressed hsa_circ_0084054 was selected and was also verified in periodontal ligament (PDL) tissue from periodontitis patients with diabetes. Then, its ring structure was tested by Sanger sequencing, RNase R, and actinomycin D assays. The bioinformatics analysis, dual luciferase reporter assay, and RIP assay were used to explore the interaction of hsa_circ_0084054/miR-508-3p/PTEN axis, whose effects on inflammation, oxidative stress, and apoptosis of PDLCs were evaluated through the measurement of inflammatory factors, reactive oxygen species (ROS), total superoxide dismutase (SOD), malondialdehyde (MDA), and Annexin V/PI assay. RESULTS: By high-throughput sequencing, it was found that hsa_circ_0084054 was significantly increased in HG + LPS group compared with control group and LPS group, which was also verified in periodontal ligament (PDL) tissue from periodontitis patients with diabetes. Silencing hsa_circ_0084054 in PDLCs decreased the expression of inflammatory factors (IL-1ß, IL-6, TNF-α), the levels of ROS and MDA, and the proportion of apoptotic cells; conversely, SOD activity was enhanced. In addition, we found that hsa_circ_0084054 could up-regulate the expression of PTEN through sponge miR-508-3p to inhibit AKT phosphorylation, finally trigger the aggravation of oxidative stress and inflammation in periodontitis patients with diabetes. CONCLUSION: hsa_circ_0084054 can aggravate inflammation and promote the progression of periodontitis with diabetes by regulating miR-508-3p/PTEN signaling axis, which may serve as a new target for the intervention of periodontitis with diabetes.

Effects of water flossing on gingival inflammation and supragingival plaque microbiota: a 12-week randomized controlled trial.

OBJECTIVES: The effects of water flossing on dental plaque removal have been suggested, but its ecological impact on dental plaque microbiota needs further investigation. In addition, whether this plaque control measure by water flossing promotes the control of halitosis still needs clinical validation. The aim of this study was to evaluate the effects of water flossing on gingival inflammation and supragingival plaque microbiota. MATERIALS AND METHODS: Seventy participants with gingivitis were randomly assigned to control (toothbrushing) and experimental (toothbrushing + water flossing) groups (n = 35). Participants were recalled at 4, 8, and 12 weeks, and their gingival index, sulcus bleeding index, bleeding on probing, dental plaque index, and oral malodor values were measured. The microbiota of supragingival plaque was further investigated using 16S rRNA sequencing and qPCR. RESULTS: Sixty-three participants completed all revisits (control: n = 33; experimental: n = 30). The experimental and control groups exhibited similar clinical characteristics and dental plaque microbiota at baseline. Adjunctive water flossing effectively reduced the gingival index and sulcus bleeding index as compared to the toothbrushing control group. The water-flossing group showed reduced oral malodor at week 12 as compared to the baseline. Consistently, the water-flossing group exhibited altered dental plaque microbiota at week 12, characterized by a depletion of Prevotella at genus level and Prevotella intermedia at species level as compared to the toothbrushing control. In addition, the plaque microbiota of water-flossing group exhibited a more aerobic phenotype, while the control group was more anaerobic. CONCLUSIONS: Daily water flossing can effectively alleviate gingival inflammation and reduce oral malodor, possibly by depleting oral anaerobes and altering the oral microbiota to a more aerobic phenotype. CLINICAL RELEVANCE: Water flossing adjunctive to toothbrushing effectively alleviated gingival inflammation, representing a promising oral hygiene practice to promote oral health. CLINICAL TRIAL REGISTRATION: The trial was registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/showprojen.aspx?proj=61797 , #ChiCTR2000038508) on September 23, 2020.

Soy isoflavones alleviate periodontal destruction in ovariectomized rats.

OBJECTIVE: The purpose of this study was to investigate whether soy isoflavone supplementation is effective in preventing periodontal destruction exacerbated by estrogen deficiency (ED) and its potential mechanism. BACKGROUND: The progression of periodontitis is affected by host factors, such as smoking, diabetes mellitus, and steroid use. Bone loss in periodontitis can be aggravated by ED. METHODS: A rat model of experimental periodontitis (EP) with ED was established by silk ligature and inoculation with Porphyromonas gingivalis, and some EP rats were subjected to bilateral ovariectomy (OVX). The treatment groups received an intravenous injection of 17-ß-estradiol (E2 B) or soy isoflavones (SI) by gavage. The rats were euthanized, and the maxillary jaws, gingiva, and serum were harvested. Tight junction protein and interleukin (IL)-17 expression, reactive oxygen species (ROS) level, and periodontal destruction were assessed. In addition, we determined whether grainyhead-like 2 (GRHL2) is required for enhancing the epithelial barrier by SI in an in vitro P. gingivalis infection model. RESULTS: Estrogen deficiency impaired the expression of genes encoding tight junction proteins in the gingiva, increased IL-17 level, and accelerated alveolar bone resorption. SI treatment alleviated tight junction protein expression, decreased IL-17 and ROS levels, and prevented the absorption of alveolar bone. Furthermore, GRHL2 expression was significantly induced by SI in human oral keratinocytes-1 (HOK-1) cells; GRHL2 knockdown impaired the expression of OCLN and ZO-1 induced by SI treatment. CONCLUSION: Soy isoflavones alleviates periodontitis in OVX rats, as observed by the increased expression of tight junction proteins, and reduced IL-17 level and alveolar bone loss. The in vitro studies suggested that the enhancement of oral epithelial barrier by SI treatment was partially dependent on GRHL2.

Research on Graphene and Its Derivatives in Oral Disease Treatment.

Oral diseases present a global public health problem that imposes heavy financial burdens on individuals and health-care systems. Most oral health conditions can be treated in their early stage. Even if the early symptoms of oral diseases do not seem to cause significant discomfort, prompt treatment is essential for preventing their progression. Biomaterials with superior properties enable dental therapies with applications in restoration, therapeutic drug/protein delivery, and tissue regeneration. Graphene nanomaterials have many unique mechanical and physiochemical properties and can respond to the complex oral microenvironment, which includes oral microbiota colonization and high masticatory force. Research on graphene nanomaterials in dentistry, especially in caries, periodontitis therapy, and implant coatings, is progressing rapidly. Here, we review the development of graphene and its derivatives for dental disease therapy.

Injectable hydrogel encapsulating Cu2MnS2 nanoplates for photothermal therapy against breast cancer.

BACKGROUND: In order to explore the possibility of treating breast cancer by local photo-therapy, a photothermal agents loaded in situ hydrogel was established. In detail, The Cu2MnS2 nanoplates were prepared by one-pot synthesis and, the thermosensitive Pluronic F127 was used as the hydrogel matrix. The Cu2MnS2 nanoplates and the hydrogel were characterized by morphous, particle size, serum stability, photothermal performance upon repeated 808 nm laser irradiation as well as the rheology features. The therapeutic effects of the Cu2MnS2 nanoplates and the hydrogel were evaluated qualitatively and quantitatively in 4T1 mouse breast cancer cells. The retention, photothermal efficacy, therapeutic effects and systemic toxicity of the hydrogel were assessed in tumor bearing mouse model. RESULTS: The Cu2MnS2 nanoplates with a diameter of about 35 nm exhibited satisfying serum stability, photo-heat conversion ability and repeated laser exposure stability. The hydrogel encapsulation did not negatively influence the above features of the photothermal agent. The nanoplates loaded in situ hydrogel shows a phase transition at body temperature and, as a result, a long retention in vivo. CONCLUSIONS: The photothermal agent embedded hydrogel played a promising photothermal therapeutic effects in tumor bearing mouse model with low systemic toxicity after peritumoral administration.

pckA-deficient Porphyromonas gingivalis W83 shows reduction in hemagglutination activity and alteration in the distribution of gingipain activity.

Bacterial metabolism during infection is related to bacterial persistence and virulence factors. Porphyromonas gingivalis is a key pathogen that contributes to chronic periodontitis. Our previous study showed that pckA, the gene encoding phosphoenolpyruvate carboxykinase, is a putative-specific pathogenic gene of virulent strains of P. gingivalis. Here, a pckA-deficient strain (ΔPG1676) was constructed in P. gingivalis W83. Virulence properties were compared between the mutant and wild-type strains. Specifically, hemagglutination activity was determined by the ability to agglutinate sheep erythrocytes. Gingipain activity was detected using synthetic-specific substrates. Gene expression levels were analyzed using RT-qPCR, and cell surface-associated polysaccharides were examined by silver staining and electron microscopy. Inactivation of the pckA gene did not affect bacterial growth and lipopolysaccharide formation but led to a reduction in hemagglutination activity and downregulation in expression of the hemagglutination-associated gene, rfa, when compared with the wild-type strain. Additionally, the ΔPG1676 mutant exhibited an alteration in the distribution of gingipain activity. Increased gingipain activity was detected on the cell surface, but a decrease in its activity in the culture supernatant was shown. Taken together, our results suggest that the pckA gene plays a role in modulating the virulence of P. gingivalis W83.

Cell cycle control, DNA damage repair, and apoptosis-related pathways control pre-ameloblasts differentiation during tooth development.

BACKGROUND: Ameloblast differentiation is the most critical stepwise process in amelogenesis, and it is controlled by precise molecular events. To better understand the mechanism controlling pre-ameloblasts (PABs) differentiation into secretory ameloblasts (SABs), a more precise identification of molecules and signaling networks will elucidate the mechanisms governing enamel formation and lay a foundation for enamel regeneration. RESULTS: We analyzed transcriptional profiles of human PABs and SABs. From a total of 28,869 analyzed transcripts, we identified 923 differentially expressed genes (DEGs) with p < 0.05 and Fold-change > 2. Among the DEGs, 647 genes showed elevated expression in PABs compared to SABs. Notably, 38 DEGs displayed greater than eight-fold changes. Comparative analysis revealed that highly expressed genes in PABs were involved in cell cycle control, DNA damage repair and apoptosis, while highly expressed genes in SABs were related to cell adhesion and extracellular matrix. Moreover, coexpression network analysis uncovered two highly conserved sub-networks contributing to differentiation, containing transcription regulators (RUNX2, ETV1 and ETV5), solute carrier family members (SLC15A1 and SLC7A11), enamel matrix protein (MMP20), and a polymodal excitatory ion channel (TRPA1). CONCLUSIONS: By combining comparative analysis and coexpression networks, this study provides novel biomarkers and research targets for ameloblast differentiation and the potential for their application in enamel regeneration.

Polymyxin B-targeted liposomal photosensitizer cures MDR A. baumannii burn infections and accelerates wound healing via M1/M2 macrophage polarization.

Multidrug-resistant (MDR) Acinetobacter baumannii infections pose a significant challenge in burn wound management, necessitating the development of innovative therapeutic strategies. In this work, we introduced a novel polymyxin B (PMB)-targeted liposomal photosensitizer, HMME@Lipo-PMB, for precise and potent antimicrobial photodynamic therapy (aPDT) against burn infections induced by MDR A. baumanni. HMME@Lipo-PMB-mediated aPDT exhibited enhanced antibacterial efficacy by specifically targeting and disrupting bacterial cell membranes, and generating increased intracellular ROS. Remarkably, even at low concentrations, this targeted approach significantly reduced bacterial viability in vitro and completely eradicated burn infections induced by MDR A. baumannii in vivo. Additionally, HMME@Lipo-PMB-mediated aPDT facilitated burn infection wound healing by modulating M1/M2 macrophage polarization. It also effectively promoted acute inflammation in the early stage, while attenuated chronic inflammation in the later stage of wound healing. This dynamic modulation promoted the formation of granulation tissue, angiogenesis, and collagen regeneration. These findings demonstrate the tremendous potential of HMME@Lipo-PMB-mediated aPDT as a promising alternative for the treatment of burn infections caused by MDR A. baumannii.

Hyperosmotic response of streptococcus mutans: from microscopic physiology to transcriptomic profile.

BACKGROUND: Oral streptococci metabolize carbohydrate to produce organic acids, which not only decrease the environmental pH, but also increase osmolality of dental plaque fluid due to tooth demineralization and consequent calcium and phosphate accumulation. Despite these unfavorable environmental changes, the bacteria continue to thrive. The aim of this study was to obtain a global view on strategies taken by Streptococcus mutans to deal with physiologically relevant elevated osmolality, and perseveres within a cariogenic dental plaque. RESULTS: We investigated phenotypic change of S. mutans biofilm upon hyperosmotic challenge. We found that the hyperosmotic condition was able to initiate S. mutans biofilm dispersal by reducing both microbial content and extracellular polysaccharides matrix. We then used whole-genome microarray with quantitative RT-PCR validation to systemically investigate the underlying molecular machineries of this bacterium in response to the hyperosmotic stimuli. Among those identified 40 deferentially regulated genes, down-regulation of gtfB and comC were believed to be responsible for the observed biofilm dispersal. Further analysis of microarray data showed significant up-regulation of genes and pathways involved in carbohydrate metabolism. Specific genes involved in heat shock response and acid tolerance were also upregulated, indicating potential cross-talk between hyperosmotic and other environmental stress. CONCLUSIONS: Hyperosmotic condition induces significant stress response on S. mutans at both phenotypic and transcriptomic levels. In the meantime, it may take full advantage of these environmental stimuli to better fit the fluctuating environments within oral cavity, and thus emerges as numeric-predominant bacterium under cariogenic conditions.

Periodontal Status and Saliva Metabolic Signature in Patients with Alzheimer's Disease.

BACKGROUND: Characterizing the periodontal status of patients with Alzheimer's disease (AD), investigating differences in salivary metabolism between patients with and without AD under the same periodontal conditions, and understanding how it is related to oral flora are critical. OBJECTIVE: We aimed to examine the periodontal condition of patients with AD and to screen salivary metabolic biomarkers from the saliva of individuals with and without AD with matched periodontal conditions. Furthermore, we aimed to explore the possible relationship between salivary metabolic changes and oral flora. METHODS: In total, 79 individuals were recruited into the experiment for periodontal analysis. Especially, 30 saliva samples from the AD group and 30 from healthy controls (HCs) with matched periodontal conditions were selected for metabolomic analysis. The random-forest algorithm was used to detect candidate biomarkers. Among these, 19 AD saliva and 19 HC samples were selected to investigate the microbiological factors influencing the alterations in saliva metabolism in patients with AD. RESULTS: The plaque index and bleeding on probing were considerably higher in the AD group. Further, Cis-3-(1-carboxy-ethyl)-3,5-cyclohexadiene-1,2-diol, dodecanoic acid, genipic acid, and N, N-dimethylthanolamine N-oxide were determined as candidate biomarkers, based on the area under the curve (AUC) value (AUC = 0.95). The results of oral-flora sequencing showed that dysbacteriosis may be a reason for the differences in AD saliva metabolism. CONCLUSION: Dysregulation of the proportion of specific bacterial flora in saliva plays a vital role in metabolic changes in AD. These results will contribute to further improving the AD saliva biomarker system.

Activatable unsaturated liposomes increase lipid peroxide of cell membrane and inhibit tumor growth.

The cancer chemodynamic therapy based on the Fenton reaction has been attracting more and more attention. However, the performance of the Fenton reaction is restricted by the unsuitable physiological pH value and inadequate H2O2 content in the tumor microenvironment (TME). In this study, we proposed a novel method of inducing lipid peroxide (LPO) of the cancer cell membrane, whose performance is not limited by the pH value and H2O2 in the TME. The activatable LPO-inducing liposomes were constructed by encapsulating Fe3+-containing compound ferric ammonium citrate (FC) in the unsaturated soybean phospholipids (SPC). It was found that the FC could be reduced by the overexpressed glutathione (GSH) in the TME and produce iron redox couple. The Fe3+/Fe2+ mediated the peroxidation of the unsaturated SPC and induced the LPO in the cancer cells. Finally, LPO accumulation led to cancer cell death and tumor growth inhibition. Furthermore, the activatable liposomes did not damage healthy tissues because of the low GSH content in normal tissues and the GSH-triggered activation of the nanocarrier. Together, our findings revealed that FC-SPC-lipo displayed excellent anti-tumor performance and its therapeutic effects are less influenced by the TME, compared with the traditional ferroptosis.

Porphyromonas gingivalis upregulates calbindin 1 and thus promotes the proliferation of gingival epithelial cells.

OBJECTIVES: This study aims to investigate the effect of calbindin 1 on the proliferation and apoptosis of gingival epithelial cells affected by Porphyromonas gingivalis (P. gingivalis)invitro. METHODS: A model of P. gingivalis infecting CA9-22 was established in vitro. At 24 h after infection, the expression of calbindin 1 (CALB1) was detected by real-time fluorescent quantitative polymerase chain reaction, Western blot, and immunofluorescence analyses. The expression of CALB1 was further inhibited by RNA interference. Cell proliferation was detected by BrdU analysis, and cell apoptosis was detected by caspase 3 activity. The expression of MDM2 and p53 was detected by Western blot analysis. RESULTS: P. gingivalis infection upregulated the expression of CALB1 in CA9-22 cells with multiplicity-dependent manner. CALB1 promoted the proliferation of CA9-22 cells, increased the expression of MDM2, and inhibited the expression of p53. Inhibiting CALB1 expression did not affect the inhibitory effect of P. gingivalis infection on CA9-22 apoptosis. CONCLUSIONS: P. gingivalis infection can promote the proliferation of CA9-22 cells by increasing CALB1 expression. The related mechanism may be associated with MDM2-p53.

Pathogenesis and treatment of wound healing in patients with diabetes after tooth extraction.

Diabetes mellitus is a common systematic chronic disease amongst dental patients. The elevated glucose microenvironment can prolong the healing of tooth extraction sockets. Therefore, the promotion of healing up tooth extraction sockets is of great clinical importance to the patients with diabetes mellitus. The current evidence indicates the mechanism of the recovery period of extraction sockets in hyperglycaemia conditions from physiological, inflammation, immune, endocrine and neural aspects. New advancements have been made in varied curative approaches and drugs in the management of wound healing of tooth extraction sockets in diabetes. However, most of the interventions are still in the stage of animal experiments, and whether it can be put into clinical application still needs further explorations. Specifically, our work showed topical administration of plasma-rich growth factor, advanced platelet-rich fibrin, leukocyte- and platelet-rich fibrin and hyaluronic acid as well as maxillary immediate complete denture is regarded as a promising approach for clinical management of diabetic patients requiring extractions. Overall, recent studies present a blueprint for new advances in novel and effective approaches for this worldwide health ailment and tooth extraction sockets healing.

Porphyromonas gingivalis Induces Increases in Branched-Chain Amino Acid Levels and Exacerbates Liver Injury Through livh/livk.

Porphyromonas gingivalis, a keystone periodontal pathogen, has emerged as a risk factor for systemic chronic diseases, including non-alcoholic fatty liver disease (NAFLD). To clarify the mechanism by which this pathogen induces such diseases, we simultaneously analyzed the transcriptome of intracellular P. gingivalis and infected host cells via dual RNA sequencing. Pathway analysis was also performed to determine the differentially expressed genes in the infected cells. Further, the infection-induced notable expression of P. gingivalis livk and livh genes, which participate in branched-chain amino acid (BCAA) transfer, was also analyzed. Furthermore, given that the results of recent studies have associated NAFLD progression with elevated serum BCAA levels, which reportedly, are upregulated by P. gingivalis, we hypothesized that this pathogen may induce increases in serum BCAA levels and exacerbate liver injury via livh/livk. To verify this hypothesis, we constructed P. gingivalis livh/livk-deficient strains (Δlivk, Δlivh) and established a high-fat diet (HFD)-fed murine model infected with P. gingivalis. Thereafter, the kinetic growth and exopolysaccharide (EPS) production rates as well as the invasion efficiency and in vivo colonization of the mutant strains were compared with those of the parental strain. The serum BCAA and fasting glucose levels of the mice infected with either the wild-type or mutant strains, as well as their liver function were also further investigated. It was observed that P. gingivalis infection enhanced serum BCAA levels and aggravated liver injury in the HFD-fed mice. Additionally, livh deletion had no effect on bacterial growth, EPS production, invasion efficiency, and in vivo colonization, whereas the Δlivk strain showed a slight decrease in invasion efficiency and in vivo colonization. More importantly, however, both the Δlivk and Δlivh strains showed impaired ability to upregulate serum BCAA levels or exacerbate liver injury in HFD-fed mice. Overall, these results suggested that P. gingivalis possibly aggravates NAFLD progression in HFD-fed mice by increasing serum BCAA levels, and this effect showed dependency on the bacterial BCAA transport system.

Raman Spectroscopy: A Potential Diagnostic Tool for Oral Diseases.

Oral diseases impose a major health burden worldwide and have a profound effect on general health. Dental caries, periodontal diseases, and oral cancers are the most common oral health conditions. Their occurrence and development are related to oral microbes, and effective measures for their prevention and the promotion of oral health are urgently needed. Raman spectroscopy detects molecular vibration information by collecting inelastic scattering light, allowing a "fingerprint" of a sample to be acquired. It provides the advantages of rapid, sensitive, accurate, and minimally invasive detection as well as minimal interference from water in the "fingerprint region." Owing to these characteristics, Raman spectroscopy has been used in medical detection in various fields to assist diagnosis and evaluate prognosis, such as detecting and differentiating between bacteria or between neoplastic and normal brain tissues. Many oral diseases are related to oral microbial dysbiosis, and their lesions differ from normal tissues in essential components. The colonization of keystone pathogens, such as Porphyromonas gingivalis, resulting in microbial dysbiosis in subgingival plaque, is the main cause of periodontitis. Moreover, the components in gingival crevicular fluid, such as infiltrating inflammatory cells and tissue degradation products, are markedly different between individuals with and without periodontitis. Regarding dental caries, the compositions of decayed teeth are transformed, accompanied by an increase in acid-producing bacteria. In oral cancers, the compositions and structures of lesions and normal tissues are different. Thus, the changes in bacteria and the components of saliva and tissue can be used in examinations as special markers for these oral diseases, and Raman spectroscopy has been acknowledged as a promising measure for detecting these markers. This review summarizes and discusses key research and remaining problems in this area. Based on this, suggestions for further study are proposed.