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Objective: Periodontitis is a complex and multifactorial disease and it is challenging to decipher its underlying causes and mechanisms. This study attempted to explore potential circulating proteins in connection to periodontitis through proteome-wide Mendelian randomisation (MR). Methods: We analysed 1722 circulating proteins to identify prospective drug targets for tackling periodontitis, using the genomic dataset from the FinnGen study. Two-sample MR was conducted to evaluate the bidirectional relationship between circulating proteins and periodontitis risk. A dataset from the UK Biobank was used to validate the findings. Single-cell analysis was performed to assess the cellular expression of the identified proteins within gingival tissues. Results: MR analyses found that genetically predicted circulating levels of von Willebrand factor A domain-containing 1 (von Willebrand factor A domain containing 1 [VWA1], odds ratios: 0.94, 95% CI 0.92-0.97, P = 1.28 × 10−5) were inversely associated with periodontitis. In contrast, the level of growth differentiation factor 15 (growth differentiation factor 15 [GDF15], odds ratios: 1.05, 95% CI 1.02-1.07, P = 2.12 × 10−5) might be associated with an increased risk of periodontitis. Single-cell analysis indicated that VWA1 was primarily expressed in endothelial cells of healthy gingival tissues, while the main source of GDF15 was not derived from periodontal cells. Conclusions: The present study suggests that certain plasma proteins like VWA1 and GDF15 may be potentially indicative of the risk and susceptibility to periodontitis. These proteins could possibly be the potential therapeutic targets for treating periodontitis, and further investigation is highly warranted.

Abstract Background Periodontitis results from host-microbe dysbiosis and the resultant dysregulated immunoinflammatory response. Importantly, it closely links to numerous systemic comorbidities, and perplexingly contributes to adverse pregnancy outcomes (APOs). Currently, there are limited studies on the distal consequences of periodontitis via oral-gut axis in pregnant women. This study investigated the integrative microbiome-metabolome profiles through multi-omics approaches in first-trimester pregnant women and explored the translational potentials. Methods We collected samples of subgingival plaques, saliva, sera and stool from 54 Chinese pregnant women at the first trimester, including 31 maternal periodontitis (Perio) subjects and 23 Non-Perio controls. By integrating 16S rRNA sequencing, untargeted metabolomics and clinical traits, we explored the oral-gut microbial and metabolic connection resulting from periodontitis among early pregnant women. Results We demonstrated a novel bacterial distinguisher Coprococcus from feces of periodontitis subjects in association with subgingival periodontopathogens, being different from other fecal genera in Lachnospiraceae family. The ratio of fecal Coprococcus to Lachnoclostridium could discriminate between Perio and Non-Perio groups as the ratio of subgingival Porphyromonas to Rothia did. Furthermore, there were differentially abundant fecal metabolic features pivotally enriched in periodontitis subjects like L-urobilin and kynurenic acid. We revealed a periodontitis-oriented integrative network cluster, which was centered with fecal Coprococcus and L-urobilin as well as serum triglyceride. Conclusions The current findings about the notable influence of periodontitis on fecal microbiota and metabolites in first-trimester pregnant women via oral-gut axis signify the importance and translational implications of preconceptional oral/periodontal healthcare for enhancing maternal wellbeing.

Municipal solid waste incineration for power generation is significant for reducing and reusing solid waste. The study conducted an integrated assessment of environment and economy on municipal solid waste incineration in China, from a “cradle to grave” perspective using 1 tonne of municipal solid waste incineration as the functional unit. The environmental impacts of each month are also calculated to analyze the dynamic change throughout one year. The results indicate that the environmental impacts are mainly concentrated in marine ecotoxicity, freshwater ecotoxicity, human carcinogenic toxicity, and human non-carcinogenic toxicity. Flue gas purification, waste incineration and transportation are the key processes, which account for 65.61 %, 18.50 %, and 11.93 % of the overall environmental impact, respectively. Urea, activated carbon, chelating agent (EDTA) and diesel fuel for transportation are key factors. The life cycle cost (LCC) is 132.26 RMB/t of waste, of which the initial capital causes the largest economic cost. When considering power generated from municipal solid waste incineration to replace electricity supply from the power grid, it achieves significant environmental benefits and the normalized environmental impact value changes from 0.85 to −12.19. The findings provide references for municipal solid waste treatment to mitigate the environmental impact and reduce the economic burden across the entire life cycle.

Objective: It is evident that periodontitis is linked to various adverse pregnancy outcomes. This prospective study explored the potential link of maternal periodontal diseases to neonatal adverse outcomes. Materials and Methods: A total of 193 generally healthy females in their third trimester (34–36 weeks) of pregnancy were enrolled. All subjects received full-mouth periodontal assessment, and the periodontal inflamed surface area (PISA) was calculated. Demographic data, lifestyles and anthropometric measurements of the neonates (e.g., body length and head circumference) were recorded. Herein, small-for-gestational age (SGA) referred to gender- and age-adjusted birth weight below the 10th percentile in line with the standard reference. Multivariable logistic regression analysis and restricted cubic spline were performed for examining the association of periodontal parameters with SGA. Results: There were 8.3% (16/193) of neonates with SGA. Significantly positive correlation existed between the percentage of tooth sites with increased probing depth and an elevated risk of SGA (OR: 1.052; P < 0.05). Yet, the PISA was positively associated with the risk of SGA (OR: 1.002; P < 0.05) as well. No significant link occurred between maternal periodontal status and other neonatal outcome measures. Conclusion: Within the limitations of this study, the findings suggest that there could be a link between maternal periodontal diseases and neonatal adverse outcomes like SGA. Further investigation is required to clarify the current findings and potential implications for promoting maternal oral/periodontal health and newborn health.

Abstract Background Polycystic ovary syndrome (PCOS) and periodontitis significantly affect women’s oral and systemic health worldwide, and yet increase the risk of cardiovascular-metabolic diseases like diabetes and coronary heart disease. Regarding the PCOS-periodontitis connection, whether sex hormones, metabolic and inflammatory mediators could account for the underlying linking mechanism needs to be further investigated. This case–control study evaluated the hormonal, metabolic and inflammatory profiles in PCOS and non-PCOS subjects with various periodontal conditions, via assessing serum and saliva samples by Raman spectroscopy. Methods A total of 66 females with PCOS and 22 systemically healthy female volunteers were recruited in a single hospital. Full-mouth periodontal examination was undertaken for identifying the subjects with periodontal health, gingivitis or periodontitis. The datasets of sex hormones and metabolic indicators were retrieved from the hospital information system. Both serum and saliva samples were collected for detecting inflammatory mediators and Raman spectroscopic assessment. The subjects were categorized into four groups according to their conditions of PCOS and periodontitis for Raman spectroscopic analysis. Partial least squares discriminant analysis was performed to examine the inter-group differences in Raman spectra. Results PCOS patients exhibited greater mean probing depth (P

Antibiotic resistance is a global public health threat, and urgent actions should be undertaken for developing alternative antimicrobial strategies and approaches. Notably, bismuth drugs exhibit potent antimicrobial effects on various pathogens and promising efficacy in tackling SARS-CoV-2 and related infections. As such, bismuth-based materials could precisely combat pathogenic bacteria and effectively treat the resultant infections and inflammatory diseases through a controlled release of Bi ions for targeted drug delivery. Currently, it is a great challenge to rapidly and massively manufacture bismuth-based particles, and yet there are no reports on effectively constructing such porous antimicrobial-loaded particles. Herein, we have developed two rapid approaches (i.e., ultrasound-assisted and agitation-free methods) to synthesizing bismuth-based materials with ellipsoid- (Ellipsoids) and rod-like (Rods) morphologies respectively, and fully characterized physicochemical properties. Rods with a porous structure were confirmed as bismuth metal-organic frameworks (Bi-MOF) and aligned with the crystalline structure of CAU-17. Importantly, the formation of Rods was a ‘two-step’ crystallization process of growing almond-flake-like units followed by stacking into the rod-like structure. The size of Bi-MOF was precisely controlled from micro-to nano-scales by varying concentrations of metal ions and their ratio to the ligand. Moreover, both Ellipsoids and Rods showed excellent biocompatibility with human gingival fibroblasts and potent antimicrobial effects on the Gram-negative oral pathogens including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Both Ellipsoids and Rods at 50 ​μg/mL could disrupt the bacterial membranes, and particularly eliminate P. gingivalis biofilms. This study demonstrates highly efficient and facile approaches to synthesizing bismuth-based particles. Our work could enrich the administration modalities of metallic drugs for promising antibiotic-free healthcare.

Abstract Background Emerging evidence shows that periodontal disease (PD) may increase the risk of Coronavirus disease 2019 (COVID-19) complications. Here, we undertook a two-sample Mendelian randomization (MR) study, and investigated for the first time the possible causal impact of PD on host susceptibility to COVID-19 and its severity. Methods Summary statistics of COVID-19 susceptibility and severity were retrieved from the COVID-19 Host Genetics Initiative and used as outcomes. Single nucleotide polymorphisms associated with PD in Genome-wide association study were included as exposure. Inverse-variance weighted (IVW) method was employed as the main approach to analyze the causal relationships between PD and COVID-19. Three additional methods were adopted, allowing the existence of horizontal pleiotropy, including MR-Egger regression, weighted median and weighted mode methods. Comprehensive sensitivity analyses were also conducted for estimating the robustness of the identified associations. Results The MR estimates showed that PD was significantly associated with significantly higher susceptibility to COVID-19 using IVW (OR = 1.024, P = 0.017, 95% CI 1.004–1.045) and weighted median method (OR = 1.029, P = 0.024, 95% CI 1.003–1.055). Furthermore, it revealed that PD was significantly linked to COVID-19 severity based on the comparison of hospitalization versus population controls (IVW, OR = 1.025, P = 0.039, 95% CI 1.001–1.049; weighted median, OR = 1.030, P = 0.027, 95% CI 1.003–1.058). No such association was observed in the cohort of highly severe cases confirmed versus those not hospitalized due to COVID-19. Conclusions We provide evidence on the possible causality of PD accounting for the susceptibility and severity of COVID-19, highlighting the importance of oral/periodontal healthcare for general wellbeing during the pandemic and beyond.

Objective: There is a need to develop easy-to-use tools to screen for periodontal conditions in daily practice. This study aimed to evaluate the FDI World Dental Federation “Chairside Guide” (FDI-CG) developed by the Task Team of the FDI Global Periodontal Health Project (GPHP) as a potential tool for screening. Methods: Databases from 3 centres in Germany, Hong Kong, and Spain (n = 519) were used to evaluate the association of the FDI-CG and its individual items with the periodontitis case definitions proposed by the Centers for Disease Control and Prevention (CDC) and the American Academy of Periodontology (AAP) for population-based surveillance of periodontitis. Results: Statistically significant differences were observed among the databases for the prevalence of periodontitis and the items included in the FDI-CG. The FDI-CG score and its individual components were significantly associated with the periodontal status in the individual databases and the total sample, with bleeding on probing showing the strongest association with severe periodontitis (odds ratio [OR] = 12.9, 95% CI [5.9; 28.0], P < .001, for those presenting bleeding on probing >50%), followed by age (OR = 4.8, 95% CI [1.7; 4.2], P = .004, for those older than 65 years of age). Those subjects with a FDI-CG score >10 had an OR of 54.0 (95% CI [23.5; 124.2], P < .001) and presented with severe periodontitis. A significant correlation was found between the different FDI-CG scoring categories (mild, moderate, and severe) and the categories for mild, moderate, and severe periodontitis using the Centers for Disease Control and Prevention and the American Academy of Periodontology criteria (r = 0.57, Spearman rank correlation test, P < .001). Conclusion: The FDI Chairside Guide may represent a suitable tool for screening the periodontal condition by general practitioners in daily dental practice.

PurposeThe effect of hyperglycemia on periodontitis is mainly based on observational studies, and inconsistent results were found whether periodontal treatment favors glycemic control. The two-way relationship between periodontitis and hyperglycemia needs to be further elucidated. This study aims to evaluate the causal association of periodontitis with glycemic traits using bi-directional Mendelian randomization (MR) approach.MethodsSummary statistics were sourced from large-scale genome-wide association study conducted for fasting glucose (N = 133,010), HbA1c (N = 123,665), type 2 diabetes (T2D, N = 659,316), and periodontitis (N = 506,594) among European ancestry. The causal relationship was estimated using the inverse-variance weighted (IVW) model and further validated through extensive complementary and sensitivity analyses.ResultsOverall, IVW showed that a genetically higher level of fasting glucose was significantly associated with periodontitis (OR = 1.119; 95% CI = 1.045–1.197; PFDR= 0.007) after removing the outlying instruments. Such association was robust and consistent through other MR models. Limited evidence was found suggesting the association of HbA1C with periodontitis after excluding the outliers (IVW OR = 1.123; 95% CI = 1.026–1.229; PFDR= 0.048). These linkages remained statistically significant in multivariate MR analyses, after adjusting for body mass index. The reverse direction MR analyses did not exhibit the causal association of genetic liability to periodontitis with any of the glycemic trait tested.ConclusionsOur MR study reaffirms previous findings and extends evidence to substantiate the causal effect of hyperglycemia on periodontitis. Future studies with robust genetic instruments are needed to confirm the causal association of periodontitis with glycemic traits.

Microbial persisters are the featured tiny sub-population of microorganisms that are highly tolerant to multiple antimicrobials. Currently, studies on persisters remain a considerable challenge owing to technical limitations. Here, we explored the application of single-cell Raman spectroscopy (SCRS) in the investigation of persisters. Escherichia coli (ATCC 25922) cells were treated with a lethal dosage of ampicillin (100 μg/mL, 32 × MIC, 4 h) for the formation of persisters. The biochemical characters of E. coli and its persisters were assessed by SCRS, and their metabolic activities were labeled and measured with D2O-based single-cell Raman spectroscopy (D2O-Ramanometry). Notable differences in the intensity of Raman bands related to major cellular components and metabolites were observed between E. coli and its ampicillin-treated persisters. Based on their distinct Raman spectra, E. coli and its persister cells were classified into different projective zones through the principal component analysis and t-distributed stochastic neighbor embedding. According to the D2O absorption rate, E. coli persisters exhibited higher metabolic activities than those of untreated E. coli. Importantly, after the termination of ampicillin exposure, these persister cells showed a temporal pattern of D2O intake that was distinct from non-persister cells. To our knowledge, this is the first report on identifying E. coli persisters and assessing their metabolic activities through the integrated SCRS and D2O-Ramanometry approach. These novel findings enhance our understanding of the phenotypes and functionalities of microbial persister cells. Further investigations could be extended to other pathogens by disclosing microbial pathogenicity mechanisms for developing novel therapeutic strategies and approaches.

Abstract Background Periodontitis links extensively to various non‐communicable diseases such as diabetes and cardiovascular disease and most recently COVID‐19 complications. Two important proteins in humans, ACE2 and TMPRSS2, have been associated with various health problems and coronavirus infection. This study was to investigate the soluble ACE2 and TMPRSS2 in saliva and serum as well as their association with periodontal status and systemic conditions. Methods The demographic background, lifestyles, full‐mouth periodontal status and medical parameters in 139 subjects were examined and recorded. Saliva and serum samples were collected for determining the levels of ACE2, TMPRSS2 and MMP8. Findings The salivary levels of ACE2 increased with the severity and complexity of periodontitis and correlated positively with alveolar bone loss and salivary MMP8 as an inflammatory biomarker. While, the salivary levels of TMPRSS2 were negatively correlated with body mass index (BMI), cholesterol/high‐density lipoprotein (HDL) ratio, low‐density lipoprotein (LDL), salivary MMP8 and number of remaining teeth. No inter‐correlation existed among ACE2 and TMPRSS2 levels in both saliva and serum. Conclusions The present study demonstrated the disparate correlation of the soluble ACE2 and TMPRSS2 with periodontal and systemic parameters. Salivary ACE2 could differentiate periodontal health and severe periodontitis, while salivary TMPRSS2 prominently linked to the metabolic parameters of obesity and cardiovascular disease. Our findings imply the potential application of the biofluidic soluble form of SARS‐CoV‐2 entry proteins in assessing oral or systemic conditions and delivering appropriate healthcare.

Periodontal diseases are initiated by the shift from microbe-host symbiosis to dysbiosis, and the disrupted host response predominantly contributes to tissue destruction. This study investigated whether and to what extent human oral keratinocytes (HOKs) challenged by a periodontal commensal or pathogen could differentially affect the chemotactic activity of THP-1 monocytes. A selected periodontal commensal (Streptococcus sanguinis ATCC 10556) and a pathogen (Porphyromonas gingivalis ATCC 33277) were cultured and inoculated, respectively, into the lower chamber of Transwell® Permeable Supports with HOKs and incubated for 2 h or 18 h at 37°C under appropriate cell growth conditions. HOKs alone served as the control for the transwell migration assay. Well-stained THP-1 monocytes were seeded in the top chamber of the device, incubated for 2 h and then collected from the lower well for quantitation of the migrated fluorescence-labeled cells by the FACSCalibur™ flow cytometer. The statistical significance was determined using one-way ANOVA. The HOKs challenged by S. sanguinis attracted a significantly higher number of THP-1 cell migration as compared with the control after 2 h or 18 h interaction (p

Microbial persisters enable the development of certain intrinsic strategies for survival with extreme tolerance to multiple antimicrobials. Porphyromonas gingivalis is considered to be the “keystone” periodontopathogen. Indeed, periodontitis, as a highly common inflammatory disease, is the major cause of severe tooth loss and edentulism in adults globally, and yet it is crucially involved in various systemic comorbidities like diabetes. We have recently revealed P. gingivalis persisters-induced perturbation of immuno-inflammatory responses and effective suppression of this key pathogen by bismuth drugs. This study further explored novel approaches to eradicating P. gingivalis persisters through synergistic combination of colloidal bismuth subcitrate (CBS) with traditional antibiotics. P. gingivalis (ATCC 33277) cells in planktonic and biofilm states were cultured to stationary phase, and then treated with metronidazole (100 mg/L), amoxicillin (100 mg/L), CBS, (100 μM) and combinations of these medications, respectively. Persister survival rate was calculated by colony-forming unit. Cell viability and cytotoxicity of CBS were assessed in human gingival epithelial cells (HGECs). Notably, CBS combined with metronidazole enabled the effective eradication of P. gingivalis persisters in planktonic mode, and nearly eliminated their existence in biofilm mode. Importantly, CBS exhibited no effects on the viability of HGECs, along with minimal cytotoxicity (

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Background: It is known that oral diseases such as periodontal (gum) disease are closely linked to various systemic diseases and disorders. Deep learning advances have the potential to make major contributions to healthcare, particularly in the domains that rely on medical imaging. Incorporating non-imaging information based on clinical and laboratory data may allow clinicians to make more comprehensive and accurate decisions. Methods: Here, we developed a multimodal deep learning method to predict systemic diseases and disorders from oral health conditions. A dual-loss autoencoder was used in the first phase to extract periodontal disease-related features from 1188 panoramic radiographs. Then, in the second phase, we fused the image features with the demographic data and clinical information taken from electronic health records (EHR) to predict systemic diseases. We used receiver operation characteristics (ROC) and accuracy to evaluate our model. The model was further validated by an unseen test dataset. Findings: According to our findings, the top three most accurately predicted chapters, in order, are the Chapters III, VI and IX. The results indicated that the proposed model could predict systemic diseases belonging to Chapters III, VI and IX, with AUC values of 0.92 (95% CI, 0.90–94), 0.87 (95% CI, 0.84–89) and 0.78 (95% CI, 0.75–81), respectively. To assess the robustness of the models, we performed the evaluation on the unseen test dataset for these chapters and the results showed an accuracy of 0.88, 0.82 and 0.72 for Chapters III, VI and IX, respectively. Interpretation: The present study shows that the combination of panoramic radiograph and clinical oral features could be considered to train a fusion deep learning model for predicting systemic diseases and disorders.

A significant portion of world population still fails to brush teeth daily. As a result, the majority of the global adult population is afflicted with chronic gingivitis, and if it is left untreated, some of them will eventually suffer from periodontitis.

Candida albicans biofilms display markedly increased antifungal resistance, and the underlying mechanisms remain unclear. This study investigated the signature profiles of C. albicans planktonic cells and biofilms in response to caspofungin (CAS) by mass spectrometry-based shotgun proteomics. We found that C. albicans biofilms were twofold more resistant to CAS with reference to planktonic cells. Notably, 9.6% of C. albicans biofilm cells survived the lethal treatment of CAS (128 μg/ml), confirmed by LIVE/DEAD staining, confocal laser scanning microscopy (CLSM) and scanning electron microscopy analyses. The responses of C. albicans planktonic cells and biofilms to CAS treatment at respective minimum inhibitory concentrations (MICs) were assessed by high-throughput proteomics and bioinformatics approaches. There were 148 and 224 proteins with >twofold difference identified from the planktonic cells and biofilms, respectively. CAS treatment downregulated several cell wall- and oxidative stress-related proteins. Whereas, CAS-induced action was compensated by markedly increased expression of many other proteins involved in cell wall integrity and stress response (e.g., heat shock proteins). Moreover, considerable expression changes were identified in metabolism-associated proteins like glycolysis, tricarboxylic acid (TCA) cycle and ATP biosynthesis. Importantly, various key proteins for cell wall integrity, stress response and metabolic regulation (e.g., PIL1, LSP1, HSP90, ICL1, and MLS1) were exclusively enriched and implicated in C. albicans biofilms. This study demonstrates that C. albicans biofilms undergo highly complicated yet complex regulation of multiple cellular pathways in response to CAS. Signature proteins essential for modulating cell wall integrity, stress response and metabolic activities may account for the antifungal resistance of C. albicans biofilms.

L-PRF is an autologous blood-derived biomaterial (ABDB) capable of releasing biologically active agents to promote healing. Little is known about its release profile of growth factors (GFs), cytokines, and MMPs. This study reported the in vitro and ex vivo release kinetics of GFs, cytokines, and MMPs from L-PRF at 6, 24, 72, and 168 h. The in vitro release rates of PDGF, TGF-β1, EGF, FGF-2, VEGF, and MMPs decreased over time with different rates, while those of IL-1β, IL-6, TNF-α, IL-8, and IL-10 were low at 6 h and then increased rapidly for up to 24 h and subsequently decreased. Of note, the release rates of the GFs followed first-order kinetics both in vitro and ex vivo. Higher rates of release were found ex vivo, suggesting that significant amounts of GFs were produced by the local cells within the wound. In addition, the half-life times of GFs locally produced in the wound, including PDGF-AA, PDGF-AB/BB, and VEGF, were significantly extended (p < 0.05). This work demonstrates that L-PRF can sustain the release of GFs and cytokines for up to 7 days, and it shows that the former can activate cells to produce additional mediators and amplify the communication network for optimizing the wound environment, thereby enhancing healing.

Periodontal ligament (PDL) cells play a pivotal role in periodontal and bone homeostasis and have promising potential for regenerative medicine and tissue engineering. There is compelling evidence that long non-coding RNAs (lncRNAs) are differentially expressed in PDL cells compared to other cell types and that these lncRNAs are involved in a variety of biological processes. This study systematically reviews the current evidence regarding the expression and regulatory functions of lncRNAs in PDL cells during various biological processes. A systematic search was conducted on PubMed, the Web of Science, Embase, and Google Scholar to include articles published up to 1 July 2021. Original research articles that investigated the expression or regulation of lncRNAs in PDL cells were selected and evaluated for a systematic review. Fifty studies were ultimately included, based on our eligibility criteria. Thirteen of these studies broadly explored the expression profiles of lncRNAs in PDL cells using microarray or RNA sequencing. Nineteen studies investigated the mechanisms by which lncRNAs regulate osteogenic differentiation in PDL cells. The remaining 18 studies investigated the mechanism by which lncRNAs regulate the responses of PDL cells to various stimuli, namely, lipopolysaccharide-induced inflammation, tumor necrosis factor alpha-induced inflammation, mechanical stress, oxidative stress, or hypoxia. We systematically reviewed studies on the expression and regulatory roles of lncRNAs in diverse biological processes in PDL cells, including osteogenic differentiation and cellular responses to inflammation, mechanical stress, and other stimuli. These results provide new insights that may guide the development of lncRNA-based therapeutics for periodontal and bone regeneration.

Objective: To profile the salivary microbiomes of a Hong Kong Chinese cohort at a species-level resolution and determine species that discriminated clinically resolved periodontitis from periodontally healthy cases.Methods: Salivary microbiomes of 35 Hong Kong Chinese subjects' under routine supportive dental care were analyzed. All subjects had been treated for any dental caries or periodontal disease with all restorative treatment completed at least 1 year ago and had ≤3 residual pockets. They were categorized based on a past diagnosis of chronic periodontitis into “healthy” (H) or “periodontitis” (P) categories. Unstimulated whole saliva was collected, genomic DNA was isolated, and high throughput Illumina MiSeq sequencing of 16S rRNA (V3-V4) gene amplicons was performed. The sequences were assigned taxonomy at the species level by using a BLASTN based algorithm that used a combined reference database of HOMD RefSeqV14.51, HOMD RefSeqExtended V1.1 and GreenGeneGold. Species-level OTUs were subjected to downstream analysis in QIIME and R. For P and H group comparisons, community diversity measures were compared, differentially abundant species were determined using DESeq2, and disease indicator species were determined using multi-level pattern analysis within the R package “indicspecies.”Results: P subjects were significantly older than H subjects (p = 0.003) but not significantly different in their BOP scores (p = 0.82). No significant differences were noted in alpha diversity measures after adjusting for age, gender, and BOP or in the beta diversity estimates. Four species; Treponema sp. oral taxon 237, TM7 sp. Oral Taxon A56, Prevotella sp. oral taxon 314, Prevotella sp. oral taxon 304, and Capnocytophaga leadbetteri were significantly more abundant in P than in the H group. Indicator species analysis showed 7 significant indicators species of P group. Fusobacterium sp oral taxon 370 was the sole positive indicator of P group (positive predictive value = 0.9, p = 0.04). Significant indicators of the H category were Leptotrichia buccalis, Corynebacterium matruchotii, Leptotrichia hofstadii, and Streptococcus intermedius.Conclusion: This exploratory study showed salivary microbial species could discriminate treated, well-maintained chronic periodontitis from healthy controls with similar gingival inflammation levels. The findings suggest that certain salivary microbiome features may identify periodontitis-susceptible individuals despite clinical disease resolution.

Lipoteichoic acid (LTA) of Enterococcus faecalis is a potent stimulator of inflammatory responses, but the effects of E. faecalis LTA on osteoclastogenesis remains far from well understood. This study showed that E. faecalis LTA significantly inhibited osteoclastogenesis of wild type murine bone marrow-derived macrophages (BMMs) in the presence of a high dose of RANKL, while the inhibition of osteoclastogenesis by E. faecalis LTA was significantly removed in BMMs with deficient expression of the transcription factor RBP-J. In addition, a few small osteoclasts were generated in BMMs with only E. faecalis LTA stimulation, presumably due to the production of TNF-α and IL-6. Furthermore, both p38 and ERK1/2 MAPK signaling pathways were activated after 24 h of E. faecalis LTA treatment, but these signaling pathways were not activated after 6 d of treatment with RANKL in mature osteoclasts. In conclusion, E. faecalis LTA, which induces inflammatory response, could inhibit RANKL-induced osteoclastogenesis via RBP-J in BMMs.

Lipopolysaccharide (LPS)-binding protein (LBP) as an acute-phase protein plays a crucial role in innate host response to bacterial challenge. Our previous study shows that LBP expression in human gingiva is associated with periodontal status. Porphyromonas gingivalis is a keystone periodontopathogen, and its LPS with lipid A structural heterogeneity critically accounts for periodontal pathogenesis. This study investigated the effects of LBP and its interactions with two featured isoforms of P. gingivalis LPS (tetra-acylated LPS1435/1449 and penta-acylated LPS1690) on the expression of pro-inflammatory cytokines in human oral keratinocytes (HOKs), and the involvement of Toll-like receptor (TLR) signaling. HOKs were pre-incubated with recombinant human LBP (rhLBP) at 10ng/ml, 100ng/ml and 1μg/ml for 1 h, followed by the treatment of P. gingivalis LPS1690 or LPS1435/1449 for 3h or 24h respectively. The expression of IL-6 and IL-8, and involvements of TLR2 and TLR4 were analyzed. The genes associated with TLR signaling were assessed by PCR array. Interestingly, rhLBP per se significantly up-regulated the expression of IL-6 and IL-8 in HOKs (p

Chlorhexidine (CHX) is a widely used antimicrobial agent in dentistry. Herein, we report the synthesis of a novel mesoporous silica nanoparticle-encapsulated pure CHX (Nano-CHX), and its mechanical profile and antimicrobial properties against oral biofilms.The release of CHX from the Nano-CHX was characterized by UV/visible absorption spectroscopy. The antimicrobial properties of Nano-CHX were evaluated in both planktonic and biofilm modes of representative oral pathogenic bacteria. The Nano-CHX demonstrated potent antibacterial effects on planktonic bacteria and mono-species biofilms at the concentrations of 50-200 µg/mL against Streptococcus mutans, Streptococcus sobrinus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Enterococccus faecalis. Moreover, Nano-CHX effectively suppressed multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans and Porphyromonas gingivalis up to 72 h.This pioneering study demonstrates the potent antibacterial effects of the Nano-CHX on oral biofilms, and it may be developed as a novel and promising anti-biofilm agent for clinical use.

Porphyromonas gingivalis is a major pathogen of periodontal disease that affects a majority of adults worldwide. Increasing evidence shows that periodontal disease is linked to various systemic diseases like diabetes and cardiovascular disease, by contributing to increased systemic levels of inflammation. Lipopolysaccharides (LPS), as a key virulent attribute of P. gingivalis, possesses significant amount of lipid A heterogeneity containing tetra- (LPS1435/1449) and penta-acylated (LPS1690) structures. Hitherto, the exact molecular mechanism of P. gingivalis LPS involved in periodontal pathogenesis remains unclear, due to limited understanding of the specific receptors and signaling pathways involved in LPS-host cell interactions.This study systematically investigated the effects of P. gingivalis LPS1435/1449 and LPS1690 on the expression of TLR2 and TLR4 signal transduction and the activation of pro-inflammatory cytokines IL-6 and IL-8 in human gingival fibroblasts (HGFs). We found that LPS1435/1449 and LPS1690 differentially modulated TLR2 and TLR4 expression. NF-κB pathway was significantly activated by LPS1690 but not by LPS1435/1449. In addition, LPS1690 induced significant expression of NF-κB and p38 MPAK pathways-related genes, such as NFKBIA, NFKB1, IKBKB, MAP2K4 and MAPK8. Notably, the pro-inflammatory genes including GM-CSF, CXCL10, G-CSF, IL-6, IL-8 and CCL2 were significantly upregulated by LPS1690 while down-regulated by LPS1435/1449. Blocking assays confirmed that TLR4-mediated NF-κB signaling was vital in LPS1690-induced expression of IL-6 and IL-8 in HGFs.The present study suggests that the tetra- and penta-acylated lipid A structures of P. gingivalis LPS differentially activate TLR4-mediated NF-κB signaling pathway, and significantly modulate the expression of IL-6 and IL-8 in HGFs. The ability to alter the lipid A structure of LPS could be one of the strategies carried-out by P. gingivalis to evade innate host defense in gingival tissues, thereby contributing to periodontal pathogenesis.

Oral mucosa as the front-line barrier in the mouth is constantly exposed to a complex microenvironment with multitudinous microbes. In this study, the interactions of mesoporous silica nanoparticles (MSNs) with primary human gingival epithelial cells were analyzed for up to 72 h, and their diffusion capacity in the reconstructed human gingival epithelia (RHGE) and porcine ear skin models was further assessed at 24 h. It was found that the synthesized fluorescent mesoporous silica nanoparticles (RITC-NPs) with low cytotoxicity could be uptaken, degraded, and/or excreted by the human gingival epithelial cells. Moreover, the RITC-NPs penetrated into the stratum corneum of RHGE in a time-dependent manner, while they were unable to get across the barrier of stratum corneum in the porcine ear skins. Consequently, the penetration and accumulation of RITC-NPs at the corneum layers of epithelia could form a “nanocoating-like barrier”. This preliminary proof-of-concept study suggests the feasibility of developing nanoparticle-based antimicrobial and anti-inflammatory agents through topical application for oral healthcare.

Scutellaria baicalensis (SB) is a traditional Chinese medicine for treating infectious and inflammatory diseases. Our recent study shows potent antibacterial effects of nanoparticle-encapsulated chlorhexidine (Nano-CHX). Herein, we explored the synergistic effects of the nanoparticle-encapsulated SB (Nano-SB) and Nano-CHX on oral bacterial biofilms. Loading efficiency of Nano-SB was determined by thermogravimetric analysis, and its releasing profile was assessed by high-performance liquid chromatographyusing baicalin (a flavonoid compound of SB) as the marker. The mucosal diffusion assay on Nano-SB was undertaken in a porcine model. The antibacterial effects of the mixed nanoparticles (Nano-MIX) of Nano-SB and Nano-CHX at 9:1 (w/w) ratio were analyzed in both planktonic and biofilm modes of representative oral bacteria. The Nano-MIX was effective on the mono-species biofilms of Streptococcus (S.) mutans, S. sobrinus, Fusobacterium (F.) nucleatum, and Aggregatibacter (A.) actinomycetemcomitans (MIC 50 μg/mL) at 24 h, and exhibited an enhanced effect against the multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans, and Porphyromonas (P.) gingivalis (MIC 12.5 μg/mL) at 24 h that was supported by the findings of both scanning electron microscopy (SEM) and confocal scanning laser microscopy (CLSM). This study shows enhanced synergistic antibacterial effects of the Nano-MIX on common oral bacterial biofilms, which could be potentially developed as a novel antimicrobial agent for clinical oral/periodontal care.

Periodontal (gum) disease is one of the main global oral health burdens and severe periodontal disease (periodontitis) is a leading cause of tooth loss in adults globally. It also increases the risk of cardiovascular disease and diabetes mellitus. Porphyromonas gingivalis lipopolysaccharide (LPS) is a key virulent attribute that significantly contributes to periodontal pathogenesis. Baicalin is a flavonoid from Scutellaria radix, an herb commonly used in traditional Chinese medicine for treating inflammatory diseases. The present study examined the modulatory effect of baicalin on P. gingivalis LPS-induced expression of IL-6 and IL-8 in human oral keratinocytes (HOKs). Cells were pre-treated with baicalin (0-80 µM) for 24 h, and subsequently treated with P. gingivalis LPS at 10 µg/ml with or without baicalin for 3 h. IL-6 and IL-8 transcripts and proteins were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The expression of nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) proteins was analyzed by western blot. A panel of genes related to toll-like receptor (TLR) signaling was examined by PCR array. We found that baicalin significantly downregulated P. gingivalis LPS-stimulated expression of IL-6 and IL-8, and inhibited P. gingivalis LPS-activated NF-κB, p38 MAPK and JNK. Furthermore, baicalin markedly downregulated P. gingivalis LPS-induced expression of genes associated with TLR signaling. In conclusion, the present study shows that baicalin may significantly downregulate P. gingivalis LPS-upregulated expression of IL-6 and IL-8 in HOKs via negative regulation of TLR signaling.

Background and Objective: Periodontal ligament progenitor cells (PDL cells) isolated from patients with inflammatory periodontitis have impaired regenerative capacity, but it is unknown whether this capacity can be recovered upon treatment and stabilization of the periodontal condition. The study aimed to investigate the expression of surface markers and the proliferation and osteogenic potential of PDL cells isolated from patients with treated stable periodontitis (S-PDL cells), periodontally healthy individuals (H-PDL cells), and patients with inflammatory periodontitis (I-PDL cells). Methods: H-PDL, I-PDL, and S-PDL cells were isolated from the extracted teeth of individuals who (1) were periodontally healthy, (2) had inflammatory periodontitis, and (3) had treated stable periodontitis, respectively. The expression levels of surface markers and the proliferative and osteogenic capacities of the PDL cells were assessed. Results: PDL cells derived from all three sources exhibited mesenchymal stem cell (MSC) characteristics. They were positive for MSC-related markers and negative for a hematopoiesis-related marker. However, S-PDL cells had higher proliferation rates, higher expression levels of osteogenic markers, higher alkaline phosphatase activity, and more calcium nodules than I-PDL cells. But all of these parameters remained lower in S-PDL cells than in H-PDL cells. Conclusions: S-PDL cells proliferated faster and had greater osteogenic potential than I-PDL cells, although these values remained lower than those in H-PDL cells. [ABSTRACT FROM AUTHOR]

Purpose: To study oral health conditions, diabetic medical complications and their association in type 2 diabetes mellitus (DM).Materials and Methods: Cross-sectional survey of 364 type 2 DM patients (63.6 +/- 10.1 years, 54% female) and 161 controls (64.1 +/- 10.6 years, 53% female) with or without essential hypertension, predominantly low-income, attending a hospital were recruited. Periodontal disease (Community Periodontal Index [CPI]) and dental status (decayed, missing and filled teeth [DMFT]) were recorded. Fasting plasma glucose and, for DM patients, HbA1C and DM complications were recorded on enrolment and follow up, respectively.Results: Many DM subjects had fair diabetic control. Both groups (control/DM) had poor oral health: DMFT = 14.5/16.8, CPI 4 = 36%/50%, (P < 0.02) while DM subjects had less DT(adjusted) = 2.1/1.4 (P < 0.01). Of the follow-up DM individuals, 294 (81%) had medical complication(s). Regression analyses showed association between advanced periodontal attachment loss (ALoss) and age, male gender, smoking and DM; MT and DMFT were associated with age, female gender, smoking, DM and hypertension. ALoss and DMFT were not associated with DM complications.Conclusions: The oral health of the surveyed Chinese subjects was poor. Type 2 DM subjects were affected more by ALoss and MT but less DT. Subjects with hypertension had higher odds for MT. [ABSTRACT FROM AUTHOR]

Objectives: Polymorphisms for toll-like receptor (TLR) 2 gene (Arg677Trp, Arg753Gln) and TLR4 gene (Asp299Gly, Thr399Ile) that are associated with impaired lipopolysaccharide (LPS) signal transduction have recently been described. The present study aimed to investigate the relationship between TLRs 2 and 4 gene polymorphisms and periodontitis in a Chinese population. Method and Materials: Forty patients with generalized aggressive periodontitis, 50 patients with chronic periodontitis, and 100 periodontally healthy controls were recruited. All these subjects were of Han Chinese ethnicity. Genomic DNA was extracted from whole-blood samples. TLRs 2 and 4 genes were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with respective restriction endonucleases. The alleles were detected by polyacrylamide gel electrophoresis and visualized with ethidium bromide. Results: Heterozygosity for the TLR2 Arg677Trp polymorphism was found in all subjects. The TLR2 Arg753Gln mutant allele was not found in periodontitis patients, while a heterozygous frequency of 6% (6 of 100) was detected in the controls. The TLR4 Asp299Gly and Thr399Ile mutant alleles were not found in any of the subjects. Conclusion: TLR2 Arg753Gln polymorphism may not be associated with aggressive or chronic periodontitis in the Chinese population. The prevalence of TLR2 Arp677Trp polymorphism seemed to be rather high, while that of TLR4 Asp299Gly and Thr399Ile polymorphisms seemed to be rather low in the Chinese population, which did not permit any conclusion regarding its effects on periodontitis. [ABSTRACT FROM AUTHOR]

Computer-aided learning (CAL) offers enormous potential in disseminating oral health care information to patients and caregivers. The effectiveness of CAL, however, remains unclear.Objectives: The purpose of this study was to systematically review published evidence on the effectiveness of CAL in disseminating oral health care information to patients and caregivers.Materials and Methods: A structured comprehensive search was undertaken among 7 electronic databases (PUBMED, CINAHL Plus, EMBASE, SCOPUS, WEB of SCIENCE, the Cochrane Library, and PsycINFO) to identify relevant studies. Randomized controlled trials (RCTs) and observational studies were included in this review. Papers were screened by 2 independent reviewers, and studies that met the inclusion criteria were selected for further assessment.Results: A total of 2915 papers were screened, and full texts of 53 potentially relevant papers (κ = 0.885) were retrieved. A total of 5 studies that met the inclusion criteria (1 RCT, 1 quasi-experimental study, and 3 post-intervention studies) were identified. Outcome measures included knowledge, attitude, behavior, and oral health. Significant improvements in clinical oral health parameters (P < .05) and knowledge/attitudes (P < .001) were reported in 2 of the studies. The 3 remaining studies reported improved oral health behaviors and confidence.Conclusion: There is a limited number of studies which have examined the effectiveness of CAL interventions for oral health care among patients and caregivers. Synthesis of the data suggests that CAL has positive impacts on knowledge, attitude, behavior, and oral health. Further high- quality studies on the effectiveness of CAL in promoting oral health are warranted. [ABSTRACT FROM AUTHOR]

Dental caries (tooth decay) is an infectious disease. Its etiology is not fully understood from the microbiological perspective. This study characterizes the diversity of microbial flora in the saliva of children with and without dental caries. Children (3-4 years old) with caries (n = 20) and without caries (n = 20) were recruited. Unstimulated saliva (2 mL) was collected from each child and the total microbial genomic DNA was extracted. DNA amplicons of the V3-V4 hypervariable region of the bacterial 16S rRNA gene were generated and subjected to Illumina Miseq sequencing. A total of 17 phyla, 26 classes, 40 orders, 80 families, 151 genera, and 310 bacterial species were represented in the saliva samples. There was no significant difference in the microbiome diversity between caries-affected and caries-free children (p > 0.05). The relative abundance of several species (Rothia dentocariosa, Actinomyces graevenitzii, Veillonella sp. oral taxon 780, Prevotella salivae, and Streptococcus mutans) was higher in the caries-affected group than in the caries-free group (p < 0.05). Fusobacterium periodonticum and Leptotrichia sp. oral clone FP036 were more abundant in caries-free children than in caries-affected children (p < 0.05). The salivary microbiome profiles of caries-free and caries-affected children were similar. Salivary counts of certain bacteria such as R. dentocariosa and F. periodonticum may be useful for screening/assessing children's risk of developing caries. [ABSTRACT FROM AUTHOR]

Candida bloodstream infections (CBI) are one of the most common nosocomial infections globally, and they account for a high mortality rate. The increasing global prevalence of drug-resistant Candida strains has also been posing a challenge to clinicians. In this study, we comprehensively evaluated the biofilm formation and production of hemolysin and proteinase of 63 CBI isolates derived from a hospital setting in Hong Kong as well as their antifungal susceptibility both in the presence and in the absence of human serum, using standard methodology. Candida albicans was the predominant species among the 63 CBI isolates collected, and non-albicans Candida species accounted for approximately one third of the isolates (36.5%). Of them, Candida tropicalis was the most common non-albicans Candida species. A high proportion (31.7%) of the CBI isolates (40% of C. albicans isolates, 10% of C. tropicalis isolates, 11% of C. parapsilosis isolates, and 100% of C. glabrata isolates) were found to be resistant to fluconazole. One of the isolates (C. tropicalis) was resistant to amphotericin B. A rising prevalence of drug-resistance CBI isolates in Hong Kong was observed with reference to a previous study. Notably, all non-albicans Candida species, showed increased hemolytic activity relative to C. albicans, whilst C. albicans, C. tropicalis, and C. parapsilosis exhibited proteinase activities. Majority of the isolates were capable of forming mature biofilms. Interestingly, the presence of serum distorted the yeast sensitivity to fluconazole, but not amphotericin B. Taken together, our findings demonstrate that CBI isolates of Candida have the potential to express to varying extent their virulence attributes (e.g., biofilm formation, hemolysin production, and proteinase activity) and these, together with perturbations in their antifungal sensitivity in the presence of serum, may contribute to treatment complication in candidemia. The effect of serum on antifungal activity warrants further investigations, as it has direct clinical relevance to the treatment outcome in subjects with candidemia. [ABSTRACT FROM AUTHOR]

To study the immune-inflammatory response and signaling mechanism of macrophages to purified Enterococcus faecalis (E. faecalis) lipoteichoic acid (LTA), intact LTA was obtained from an E. faecalis clinical strain P25RC using the butanol method and hydrophobic interaction chromatography purification. The fractions containing LTA were determined using phosphate detection. Contaminations with lipopolysaccharide and proteins were excluded using the Limulus amoebocyte lysate assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. LTA was analyzed using nuclear magnetic resonance. Prior to LTA stimulation assays, THP-1 monocytes were pretreated with phorbol 12-myristate 13-acetate to differentiate into macrophages. Macrophages were treated with LTA in concentration gradients and cells without LTA treatment as the control. Gene expression of TLR2, CD14 and MyD88 were evaluated by quantitative polymerase chain reaction. Tumor necrosis factor-α (TNF-α) and interleukin (IL)-10 were quantified using ELISA. The activated and total nuclear factor-αB (NF-αB) p65 and three mitogen-activated protein kinases (p38, ERK1/2 and JNK) were assessed using western blot analysis. E. faecalis LTA induced the gene expression of TLR2 and MyD88 whilst it downregulated CD14, suggesting a TLR2-dependent and CD14-independent immune-inflammatory activity. LTA stimulated the expression of pro-inflammatory cytokine TNF-α (P<0.05), but not the anti-inflammatory cytokine IL-10. In conclusion, E. faecalis LTA stimulated the expression of TNF-α in macrophages possibly through the NF-αB and p38 pathways. [ABSTRACT FROM AUTHOR]

Background: Porphyromonas gingivalis lipopolysaccharide (LPS) is a crucial virulence factor strongly associated with chronic periodontitis which is the primary cause of tooth loss in adults. It exhibits remarkable heterogeneity containing tetra-(LPS1435/1449) and penta-(LPS1690) acylated lipid A structures. Human gingival fibroblasts (HGFs) as the main resident cells of human gingiva play a key role in regulating matrix metalloproteinases (MMPs) and contribute to periodontal homeostasis. This study investigated the expression and regulation of MMPs1-3 and tissue inhibitors of MMP-1 (TIMP-1) in HGFs in response to P. gingivalis LPS1435/1449 and LPS1690 and hexa-acylated E. coli LPS as a reference. The expression of MMPs 1-3 and TIMP-1 was evaluated by real-time PCR and ELISA. Results: The MMP-3 mRNA and protein were highly upregulated in P. gingivalis LPS1690- and E. coli LPS-treated cells, whereas no induction was observed in P. gingivalis LPS1435/1449-treated cells. On the contrary, the expression of MMP-1 and -2 was not significantly affected by P. gingivalis LPS lipid A heterogeneity. The TIMP-1 mRNA was upregulated in P. gingivalis LPS1435/1449- and E. coli LPS-treated cells. Next, signal transduction pathways involved in P. gingivalis LPS-induced expression of MMP-3 were examined by blocking assays. Blockage of p38 MAPK and ERK significantly inhibited P. gingivalis LPS1690-induced MMP-3 expression in HGFs. Conclusion: The present findings suggest that the heterogeneous lipid A structures of P. gingivalis LPS differentially modulate the expression of MMP-3 in HGFs, which may play a role in periodontal pathogenesis [ABSTRACT FROM AUTHOR]

The article highlights a study on the effect of periodontal treatment on circulating progenitor cell (CPC) count and vascular endothelial function. The authors used a single-blind, randomized controlled trial in the study, where healthy subjects were assigned into two groups, a Treatment group where periodontal treatment was given immediately and a Control group where treatment was postponed for three weeks. They discovered that the significant decrease in circulating CD34+ cells count affected bleeding in the Treatment group compared to the Controls.

Background: The purpose of this case-control study is to investigate the periodontal conditions in elderly men with and without osteoporosis or osteopenia and to determine their possible association with periodontal destruction. Methods: A total of 200 community-dwelling Chinese males (age range: 69 to 78 years; mean ± SD age: 71.9 ± 3.3 years) were recruited from the Jockey Club Center for Osteoporosis Care and Control, The Chinese University of Hong Kong, including 67 subjects with osteoporosis, 66 subjects with osteopenia, and 67 age-matched normal control subjects based on bone mineral density at the hip, spine, and whole body measured by dual-energy x-ray densitometry. All subjects were interviewed using questionnaires and received a full-mouth periodontal examination. Results: Subjects with osteoporosis exhibited a significantly higher percentage of sites with clinical attachment loss (AL) ≥6 mm compared to subjects with osteopenia (P<0.05); subjects with osteoporosis also showed a greater percentage of sites with interproximal gingival recession (GR) ≥5 mm than did control subjects (P<0.05) after excluding smokers. Subjects with osteoporosis were more likely (odds ratio = 3.3; P<0.05) to exhibit interproximal GR ≥5 mm than were control subjects. Osteoporosis remained significantly associated with severe clinical AL and interproximal GR after adjusting for age, supragingivai plaque, and number of teeth lost. Conclusion: This study suggests that osteoporosis is associated with severe clinical AL and interproximal GR in elderly Chinese men. [ABSTRACT FROM AUTHOR]

Lu Q, Jin L. Human gingiva is another site of C-reactive protein formation. J Clin Periodontol 2010; 37: 789–796. doi: 10.1111/j.1600-051X.2010.01600.x. Objectives: C-reactive protein (CRP) is primarily synthesized in the liver. It is hypothesized that human gingiva per se may produce CRP and its expression could be associated with IL-6. This study elucidated the CRP expression profile in human gingiva and its possible association with IL-6. Materials and Methods: Ninety-four gingival biopsies were collected from 44 subjects with chronic periodontitis and 18 periodontally healthy subjects. CRP protein was detected by immunohistochemistry and Western blotting, while CRP and IL-6 mRNAs were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR. CRP protein expression in the reconstituted human gingival epithelia (RHGE) was examined by the particle-enhanced immunoturbidimetric assay and Western blotting. Results: CRP protein was detected in gingival tissues from patients and healthy subjects by immunohistochemistry and confirmed by Western blotting. Its expression pattern and level at 16 pairs of periodontal pocket tissues and the adjacent clinically healthy tissues from 16 patients were significantly interrelated ( rs=0.693, p<0.01). CRP mRNA expression was strongly correlated with IL-6 ( r=0.694, p<0.001). Both CRP protein and mRNA were detected in the RHGE. Conclusions: The present study shows for the first time that human gingiva is able to produce CRP in situ that may be associated with IL-6 activity. [ABSTRACT FROM AUTHOR]

CFTR (cystic fibrosis transmembrane conductance regulator) is a cAMP-activated chloride channel that regulates electrolyte and water transport. The present study investigated the expression and localization of CFTR in human gingiva and explored the possible association of CFTR with periodontal conditions. CFTR expression in gingival biopsies from five periodontally healthy subjects and ten subjects with chronic periodontitis and in the RHGE (reconstituted human gingival epithelia) was detected by immunohistochemistry, whereas its expression in gingival biopsies was analysed by immunofluorescence staining. CFTR mRNA was analysed by reverse transcription-PCR. CFTR mRNA was detected in human gingival epithelia and RHGE. CFTR protein was detected in gingival biopsies from both healthy subjects and individuals with periodontitis and in RHGE. In healthy subjects, CFTR expression was mainly confined to the granular and spinous layers of epithelia and localized on the cell membrane. In patients with periodontitis, CFTR was detected in all layers of epithelia and the underlying connective tissues. The mean CFTR expression levels in periodontitis patients were significantly higher than those in healthy subjects. The present study for the first time showed the expression and localization of CFTR in human gingival epithelia. Elevated CFTR expression in periodontitis subjects implies the possible involvement of CFTR in periodontal disease pathogenesis. Further study is warranted to confirm the present findings. [ABSTRACT FROM AUTHOR]

Background: DNA methylation of certain genes frequently occurs in neoplastic cells. Although the cause remains unknown, many genes have been identified with such atypical methylation in neoplastic cells. The hypermethylation of E-Cadherin and Cyclooxygenase 2 (COX-2) in chronic inflammation such as chronic periodontitis may demonstrate mild lesion/mutation epigenetic level. This study compares the hypermethylation status of E-Cadherin and COX-2 genes which are often found in breast cancer patients with that in chronic periodontitis. Methods: Total DNA was extracted from the blood samples of 108 systemically healthy non-periodontitis subjects, and the gingival tissues and blood samples of 110 chronic periodontitis patient as well as neoplastic tissues of 106 breast cancer patients. Methylation-specific PCR for E-Cadherin and COX-2 was performed on these samples and the PCR products were analyzed on 2% agarose gel. Results: Hypermethylation of E-Cadherin and COX-2 was observed in 38% and 35% of the breast cancer samples, respectively. In chronic periodontitis patients the detection rate was 25% and 19% respectively, and none was found in the systemically healthy non-periodontitis control subjects. The hypermethylation status was shown to be correlated among the three groups with statistical significance (p < 0.0001). The methylation of CpG islands in E-Cadherin and COX-2 genes in periodontitis patients occurs more frequently in periodontitis patients than in the control subjects, but occurs less frequently than in the breast cancer patients. Conclusions: This set of data shows that the epigenetic change in E-Cadherin and Cyclooxygenase-2 is associated with chronic periodontitis. The epigenetic changes presented in chronic inflammation patients might demonstrate an irreversible destruction in the tissues or organs similar to the effects of cancer. Chronic periodontitis to some extent might be associated with DNA hypermethylation which is related to cancer risk factors. [ABSTRACT FROM AUTHOR]

Porphyromonas gingivalis lipopolysaccharide (LPS) is a crucial virulence factor strongly involved in the development of chronic periodontitis. It displays a significant amount of lipid A structural heterogeneity, containing both tetra- (LPS1435/1449) and penta-acylated (LPS1690) lipid A structures with opposing effects on E-selectin expression in human endothelial cells. Little is known about how these two isoforms of P. gingivalis LPS could differentially affect host innate immune responses in human gingival epithelia. The present study compares the modulatory effects of P. gingivalis LPS1435/1449 and LPS1690 on the expression of human β-defensins (hBDs) in the reconstituted human gingival epithelium, and examines the involvements of a panel of pattern recognition receptors in the modulatory effects concerned. It is shown that hBD-1, hBD-2 and hBD-3 mRNAs are significantly up-regulated by P. gingivalis LPS1690, but down-regulated by P. gingivalis LPS1435/1449. Toll-like receptor (TLR) 2 and CD14 mRNAs are also differentially regulated, and the modulation of hBD-2 expression may be through the co-operation of both TLR2 and TLR4. This study suggests that P. gingivalis LPS with different lipid A structures could differentially modulate host innate immune responses in human gingival epithelia, which may be a hitherto undescribed novel pathogenic mechanism of P. gingivalis in periodontal pathogenesis. [ABSTRACT FROM AUTHOR]

Aim: Emerging evidence shows that periodontal disease is associated with endothelial dysfunction. The purpose of this study was to determine the association between chronic periodontitis (CP) and circulating endothelial progenitor cells (EPC). Materials and Methods: Eighty-six non-smoking subjects (36 males and 50 females, aged 35–80 years) were recruited, including 23 subjects with no or mild CP and 63 subjects with moderate to severe CP. The levels of circulating EPC were quantitatively determined by fluorescence-activated cell analysis, including CD34+/kinase insert domain-containing receptor (KDR)+ (more mature EPC) and CD133+/KDR+ (less mature EPC). Periodontal conditions, the intima–media thickness of carotid arteries and circulating biomarkers were examined. Results: Subjects with moderate to severe CP exhibited an increased risk of high EPC count, compared with those with no or mild CP: CD34+/KDR+ EPC [odds ratio (OR)=9.5, 95% confidence interval (95% CI) 1.5–61.0, p=0.018; CD133+/KDR+ EPC, OR=4.6, 95% CI 1.1–19.5, p=0.039]. C-reactive protein was significantly associated with high CD34+/KDR+ EPC count and age was inversely related with high EPC count. Age, gender and CD34+/KDR+ EPC were independent variables of increased carotid intima–media thickness ( p<0.05). Conclusion: This study shows for the first time that moderate to severe CP is associated with an increased level of circulating EPC. [ABSTRACT FROM AUTHOR]

Background: It is evident that diabetes and periodontal disease are closely interrelated. Accumulation of advanced glycation end products (AGEs), coupled with exaggerated host responses to bacterial infection, may account for the increased periodontal destruction observed in patients with uncontrolled diabetes. The present study investigated the effects of AGEs on the viability of human gingival fibroblasts (HGFs) and the expression of types I and III collagen in HGFs. Methods: The cell viability of HGFs was examined by methylthiazolet-etrazolium assay, whereas the expression of types I and III collagen message and protein was detected by real-time quantitative reverse transcription-polymerase chain reaction and sandwich enzyme-linked immunosorbent assay, respectively. Results: AGEs significantly suppressed the cell viability of HGFs from 24 to 72 hours (P<0.01). A high concentration of glucose (25 mmol/l) in the culture media exaggerated the inhibition of the survival rate of HGFs (P<0.01). The expression of collagen types I and III messages and proteins was significantly downregulated at 72 hours by AGEs in a concentration-dependent manner (P <0.05). Moreover, the synthesis of intracellular types I and II collagen protein was markedly inhibited by AGEs (P<0.05). Conclusions: AGEs may suppress the cell viability of HGFs and downregulate the expression of types I and III collagen by the cells. Further investigations are warranted to clarify the molecular mechanisms of AGEs in the regulation of cell function and collagen metabolism in patients with diabetes and periodontitis. [ABSTRACT FROM AUTHOR]

Background: This study investigated the possible association of nifedipine (NIF) intake and diabetes mellitus (DM) with periodontal destruction. Methods: A group of Chinese subjects (N = 1,083, age: 63 ± 8.7 years) were screened. Three hundred fifty-eight non-smokers with hypertension were selected for the study and were grouped based on DM status as non-DM and DM groups, DM(-) and DM(+) respectively. NIF(+) and NIF(-) indicated NIF intake or not. The groups were further divided: NIF(-)/DM(-) (n = 135); NIF(+)/DM(-) (n = 108); NIF(-)/DM(+) (n = 64); and NIF(+)/DM(-) (n = 51). The periodontal conditions in anterior teeth were assessed using plague index, sulcus bleeding index, clinical attachment loss (AL), probing depth (PD), and the number of missing teeth. Results: Using analysis of covariance, NIF intake was associated with mean PD and extent of PD ≥4 mm in the non-DM and DM groups. The subjects in the NIF(+)/DM(+) subgroup showed greater mean AL and percentage of sites with AL ≥5 mm and AL ≥7 mm than those in NIF(-)/DM(+) subgroup, whereas no significant difference existed between subjects in NIF(-)/DM(-) and NIF(+)/DM(-) subgroups. The NIF(+)/ DM(+) subgroup exhibited a greater percentage of sites with AL ≥5 mm (35.5%) compared to the other three subgroups (24.7% for NIF[-]/DM[-], P = 0.004; 25.0% for NIF[+]/DM[-], P = 0.007; and 25.2% for NIF[-]/DM[+], P = 0.016). Logistic regression analysis showed that the NIF(+)/DM(+) subgroup had a significantly higher risk for having >10% of sites with AL ≥5 mm compared to the NIF(-)/DM(-) subgroup (odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.2 to 7.4; P = 0.022), the NIF(+)/DM(-) subgroup (OR = 3.1 ; 95% CI: 1.2 to 8.1; P = 0.020), and the NIF(-)/DM(+) subgroup (OR = 5.1; CI: 1.8 to 14.3; P = 0.002). Conclusion: NIF intake may increase the risk for periodontal destruction in patients with type 2 DM. [ABSTRACT FROM AUTHOR]

Aim: To identify risk indicators associated with tooth loss and periodontitis in treated patients responsible for arranging supportive periodontal care (SPC). Materials and Methods: Ninety-seven Chinese subjects (34–77 years) who showed favourable responses to periodontal therapy provided in a teaching hospital 5–12 years previously were recalled. They were advised to seek regular SPC on discharge. Background information, general health status, smoking, oral hygiene habits, follow-up dental care, tooth loss, and periodontal parameters were investigated. Multiple regression analysis was performed. Results: Two hundred and fifty-six teeth had been lost, 195 because of self-reported periodontal reasons. Up to 26.8% sites were with pockets ⩾6 mm. Positive correlations were found between total/periodontal tooth loss and (i) smoking pack-years, (ii) time spent on oral hygiene, (iii) years since therapy's conclusion, (iv) age, and negative correlations with (v) inter-dental brush use, and (vi) education levels. Tooth loss by arch was correlated with wearing of removable partial denture in that arch. Percentage sites with pockets ⩾6 mm were significantly negatively correlated with percentage sites without bleeding on probing. Conclusions: Smokers, more elderly patients, removable partial denture wearers, and patients with lower education levels or not using inter-dental brushes ought to be targeted for clinic-based SPC. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the interrelationship of in vivo expression of lipopolysaccharide-binding protein (LBP) and membrane-bound CD14 (mCD14) in human gingival tissues as well as the coexpression of Toll-like receptors (TLR) 2 and 4 in association with periodontal conditions. Methods: Gingival biopsies were collected from 43 subjects with chronic periodontitis, including periodontal pocket tissues (PoTs) and clinically healthy gingival tissues (HT-Ps), and from 15 periodontally healthy subjects as controls (HT-Cs). The expression of LBP, CD14, TLR 2, and TLR 4 was detected by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Results: LBP and mCD14 peptides were simultaneously detected in 91% of PoTs, 85% of HT-Ps, and 100% of HT-Cs. LBP and mCD14 mRNAs were simultaneously detected in 55% of PoTs, 55% of HT-Ps, and 75% of HT-Cs. The expression of LBP was confined to the gingival epithelium, whereas mCD14 was observed around the epithelium-connective tissue interface. A positive correlation existed between LBP and mCD14 peptides in both detection expression (rs = 0.608; P<0.001) and expression levels (r = 0.304; P <0.05) of these two molecules. In PoTs, TLR 2 was detected in both pocket epithelia and macrophage-like cells in connective tissues, whereas TLR 4 was predominantly detected in connective tissues. In HT-Ps and HT-Cs, a weak expression of TLR 2 was found in gingival epithelia, and no TLR 4 expression was detected. In PoTs, mCD14 was codetected on CD68-labeled macrophages in the underlying connective tissues of pocket epithelium as well as on CD1a-labeled dendritic cells in the pocket epithelium and connective tissues interface. No similar expression profile was detected in HT-Ps and HT-Cs. Conclusions: This study suggests that the in vivo expression of LBP and mCD14 may be interrelated. Altered cellular expression profiles of mCD14 and TLR 2 and 4 in periodontal pocket tissues imply that these pattern recognition receptors may play a role in periodontal pathogenesis. [ABSTRACT FROM AUTHOR]