Identification of a new genetic variant (G231N, E232T, N235D) of peptidylarginine deiminase from P. gingivalis in advanced periodontitis.

Chronic periodontitis (CP), an inflammatory disease of periodontal tissues driven by a dysbiotic subgingival bacterial biofilm, is also associated with several systemic diseases, including rheumatoid arthritis (RA). Porphyromonas gingivalis, one of the bacterial species implicated in CP as a keystone pathogen produces peptidyl arginine deiminase (PPAD) that citrullinates C-terminal arginine residues in proteins and peptides. Autoimmunity to citrullinated epitopes is crucial in RA, hence PPAD activity is considered a possible mechanistic link between CP and RA. Here we determined the PPAD enzymatic activity produced by clinical isolates of P. gingivalis, sequenced the ppad gene, and correlated the results with clinical determinants of CP in patients from whom the bacteria were isolated. The analysis revealed variations in PPAD activity and genetic diversity of the ppad gene in clinical P. gingivalis isolates. Interestingly, the severity of CP was correlated with a higher level of PPAD activity that was associated with the presence of a triple mutation (G231N, E232T, N235D) in PPAD in comparison to W83 and ATCC 33277 type strains. The relation between mutations and enhanced activity was verified by directed mutagenesis which showed that all three amino acid residue substitutions must be introduced into PPAD expressed by the type strains to obtain the super-active enzyme. Cumulatively, these results may lead to the development of novel prognostic tools to assess the progress of CP in the context of associated RA by analyzing the ppad genotype in CP patients infected with P. gingivalis.

A Mendelian randomization study between chronic periodontitis and non-alcoholic fatty liver disease.

BACKGROUND AND OBJECTIVE: Observational studies have suggested a potential association between non-alcoholic fatty liver disease (NAFLD) and chronic periodontitis (CP). However, these studies are prone to confounding factors. The aim of this study was to assess the causal relationship between NAFLD and CP using a two-sample bidirectional Mendelian randomization (MR) analysis method. METHODS: Datasets of CP and NAFLD were retrieved from the European database, and instrumental variables (IVs) related to exposure were selected for the MR analysis. Sensitivity tests, including heterogeneity and horizontal pleiotropy tests, were conducted to ensure the consistency of the selected IVs, following which the analysis results were visualized. RESULTS: Genetic variants associated with CP and NAFLD were identified as IVs, and the MR assessment was performed using the summary data (CP: 3046 cases and 195 395 controls; NAFLD: 894 cases and 217 898 controls). CP increased the risk of NAFLD (inverse variance weighted [IVW], b = 0.132 > 0, p = .006 < .05), whereas the reverse was not observed (IVW, b = -0.024 < 0, p = .081 > .05). The sensitivity analysis indicated no heterogeneity or horizontal pleiotropy. CONCLUSION: The MR analysis suggested that CP could increase the risk of NAFLD among European populations.

Evaluation of matrix metalloproteinase-1, -2, -3, -7, and -13 gene polymorphisms in patients with chronic periodontitis and healthy controls.

OBJECTIVES: The current study aimed to investigate the association of matrix metalloproteinase- (MMP-) 1, -2, -3, -7, and -13 gene polymorphisms with chronic periodontitis (CP) in an Iranian population. MATERIALS AND METHODS: In this case-control study, 87 subjects with CP and 89 periodontally healthy subjects were allocated to case and control groups, respectively. Subjects' venous blood samples (5 cc) were collected, and DNA extraction was performed. A spectrophotometer was utilized to assess the concentration of extracted DNAs. The desired gene polymorphisms were examined using restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) followed by electrophoresis. Statistical analyses were done using the Pearson Chi-Square test, odds ratio, and t-Test using SPSS Version 28. RESULTS: The MMP-1 (-1607 1G/2G) rs1799750, MMP-3 (-1171 5A/6A) rs3025058, and MMP-7 (-181 A/G) rs11568818 gene polymorphisms significantly differed between case and control groups (PV = 0.019, 0.007, and 0.028, respectively). In contrast, the gene polymorphisms of MMP-2 (-1306 C/T) rs243865 and MMP-13 (-77 A/G) rs2252070 did not make a significant difference. Regarding allele frequencies, the presence of the 2G allele in the MMP-1 (-1607) rs1799750 genotype increased the CP susceptibility significantly, while subjects with the 6A allele in their MMP-3 (-1171) rs3025058 genotype showed significantly lower susceptibility to CP (PV = 0.008 and < 0.001, respectively). CONCLUSION: In the studied population, gene polymorphisms in the DNA sequences of MMP-1 (-1607 1G/2G) rs1799750, MMP-3 (-1171 5A/6A) rs3025058, and MMP-7 (-181 A/G) rs11568818 may have impacts on CP incidence. CLINICAL RELEVANCE: Clinicians should be cautious about the association between MMP-1, MMP-3, and MMP-7 gene polymorphisms and the incidence of chronic periodontitis during periodontal treatment planning.

Exploratory research on the probable shared molecular mechanism and transcription factors between chronic periodontitis and chronic obstructive pulmonary disease.

OBJECTIVES: To investigate possible cross-talk genes, associated pathways, and transcription factors between chronic periodontitis (CP) and chronic obstructive pulmonary disease (COPD). METHODS: The gene expression profiles of CP (GSE10334 and GSE16134) and COPD (GSE76925) were downloaded from the GEO database. Differential expression and functional clustering analyses were performed. The protein­protein interaction (PPI) network was constructed. The core cross-talk genes were filtered using four topological analysis algorithms and modular segmentation. Then, functional clustering analysis was performed again. RESULTS: GSE10334 detected 164 differentially expressed genes (DEGs) (119 upregulated and 45 downregulated). GSE16134 identified 208 DEGs (154 upregulated and 54 downregulated). GSE76925 identified 1 408 DEGs (557 upregulated and 851 downregulated). The PPI network included 21 nodes and 20 edges. The final screening included seven cross-talk genes: CD79A, FCRLA, CD19, IRF4, CD27, SELL, and CXCL13. Relevant pathways included primary immunodeficiency, the B-cell receptor signaling pathway, and cytokine-cytokine receptor interaction. CONCLUSIONS: This study indicates the probability of shared pathophysiology between CP and COPD, and their cross-talk genes, associated pathways, and transcription factors may offer novel concepts for future mechanistic investigations.

Elucidation of common molecular diagnostic biomarkers between chronic periodontitis and Parkinson's disease via bioinformatics analyses.

BACKGROUND AND OBJECTIVES: Parkinson's disease (PD) and chronic periodontitis (CP) are both inflammatory diseases; a correlation between the two diseases has been reported, but the underlying mechanisms of this association have not been investigated. We investigated the common molecular mechanisms between PD and CP and the role of immune cells in the pathogenesis of them using bioinformatics analyses to elucidate the association between the two diseases. METHODS: We obtained gene expression data from the Gene Expression Omnibus (GEO) database: GSE10334, GSE16134, and GSE23586 for CP gingival samples and GSE20146 for PD brain samples. Subsequently, we conducted an enrichment analysis of the differentially expressed genes (DEGs) using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses. Moreover, all DEGs were analysed for protein-transcription factor interactions and protein-immune cell co-expression. We constructed protein-transcription factor, protein-protein interaction (PPI), and protein-immune cell co-expression networks using the Cytoscape software. Moreover, we identified the hub genes and investigated them for potential diagnostic value. RESULTS AND CONCLUSION: We identified 99 DEGs in the three CP datasets, 520 DEGs in the PD dataset and found five common DEGs in the CP and PD datasets, namely CXCR4, CXCL8, CD19, RPTN, and SLC16A9. These common DEGs identified in our study may have a potential impact on disease pathogenesis through the involvement of CXCR4-CXCL8-CD19 protein-complexes in dendritic cells. Therefore, CD19, LCP2, CXCR4, and LYN could be used as target molecules for the clinical diagnosis of both diseases.

Osteoprotective Role of the Mir338 Cluster Ablation during Periodontitis.

Periodontitis is a chronic inflammatory disease that compromises the integrity of the supporting tissues of the teeth and leads to the loss of the alveolar bone. The Mir338 cluster has been proven to be a potential target for the treatment of osteoporosis and is also enriched in gingival tissues with periodontitis; however, its role in periodontitis remains unknown. Here, we aimed to use periodontitis as a model to expand our understanding of the Mir338 cluster in osteoimmunology and propose a new target to protect against bone loss during periodontitis progression. Significant enrichment of the Mir338 cluster was validated in gingival tissues from patients with chronic periodontitis and a ligature-induced periodontitis mouse model. In vivo, attenuation of alveolar bone loss after 7 d of ligature was observed in the Mir338 cluster knockout (KO) mice. Interestingly, immunofluorescence and RNA sequencing showed that ablation of the Mir338 cluster reduced osteoclast formation and elevated the inflammatory response, with enrichment of IFN-γ and JAK-STAT signaling pathways. Ablation of the Mir338 cluster also skewed macrophages toward the M1 phenotype and inhibited osteoclastogenesis via Stat1 in vitro and in vivo. Furthermore, the local administration of miR-338-3p antagomir prevented alveolar bone loss from periodontitis. In conclusion, the Mir338 cluster balanced M1 macrophage polarization and osteoclastogenesis and could serve as a novel therapeutic target against periodontitis-related alveolar bone loss.

Diagnostic potential of miR-200 family members in gingival crevicular fluid for chronic periodontitis: correlation with clinical parameters and therapeutic implications.

OBJECTIVE: The purpose of this study was to evaluate the potential of miR-200 family members in gingival crevicular fluid (GCF) as diagnostic biomarkers for chronic periodontitis (CP), aiming to provide valuable insights for the early detection and management of the disease. METHODS: GSE89081 dataset profiled miRNAs in GCF derived from 5 healthy and 5 periodontitis was analyzed by GEO2R. Quantitative real-time PCR was used to quantify the expression levels of miR-200 family members (miR-200a-3p, miR-200a-5p, miR-200b-3p, miR-200b-5p, miR-200c-3p, miR-200c-5p, miR-141-3p, miR-141-5p, and miR-429) in the GCF samples from 103 CP patients and 113 healthy controls. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic potential of miR-200 family members in differentiating CP patients from healthy controls. RESULTS: By analyzing the GSE89081 dataset, miR-200a-5p, miR-200b-5p and miR-200c-5p were significantly upregulated in GCF of the CP patients compared to the healthy control. In this study, miR-200a-3p, miR-200a-5p, miR-200b-3p, miR-200b-5p, miR-200c-3p, miR-200c-5p were significantly increased in GCF of CP patients compared to the healthy control, while miR-141 and miR-429 did not show significant differences. MiR-200a, -200b and 200c had good diagnostic value, and when these miRNAs were combined, they demonstrated excellent diagnostic value for CP with an AUC of 0.997, sensitivity of 99.03%, and specificity of 98.23%. MiR-200a, -200b and 200c in GCF showed significant and positive correlation with plaque index (PI), gingival index (GI), bleeding on probing (BOP), clinical attachment level (CAL), and probing pocket depth (PPD). CONCLUSION: MiR-200a, -200b and 200c in GCF may serve as potential biomarkers for the early diagnosis of CP, which was correlated with clinical parameters, being therapeutic targets for CP.

Screening of interleukin 17F gene polymorphisms and eight subgingival pathogens in chronic periodontitis in Libyan patients.

Background: Chronic periodontitis (CP) is triggered by periodontal pathogens influenced by genetic and environmental factors. Recent studies have suggested that anti-inflammatory cytokines such as interleukin 17 (IL-17) play a prominent role in the pathogenesis of CP.Aim: This study aimed to investigate the association between eight sub-gingival pathogens and interleukin 17F (IL-17F) gene single nucleotide polymorphisms with CP among Libyans.Materials and Methods: A case-control study was conducted on 100 individuals between the ages of 25-65 years. Species-specific 16S rRNA primers for each pathogen were used in a multiplex PCR reaction to detect sub-gingival pathogens from a paper point sample. DNA was also extracted from buccal swab samples and IL-17F polymorphisms were detected by Sanger sequencing.Results: A highly significant association between the seven sub-gingival pathogens and CP, (p-value 0.0001) and a high prevalence of P. intermedia (100%), T. forsythia (96%), T. denticola and E. corrodens (92%), P. gingivalis (82%), C. rectus (74%), P. nigrescens (72%), A. actinomvcetcmcomitans (40%) were found in the case group compared with control group. A novel variant in the c. *34 G>A in IL-17F gene caused a change in glutamic amino acid to lysine amino acid, position on chromosome number (6) in the third exon, mRNA/genomic position 597, found in 14.6% of CP patients (p-value = 0.010) while the IL-17F (rs763780) SNP showed no association with CP (p-value = 0.334).Conclusion: P. intermedia appear as keystone pathogen for CP in the Libyan population. A novel variant in the IL-7F gene may be related to the severity of CP.

Analysis of the Effects of IL-6 -572 C/G, CRP -757 A/G, and CRP -717 T/C Gene Polymorphisms; IL-6 Levels; and CRP Levels on Chronic Periodontitis in Coronary Artery Disease in Indonesia.

Interleukin 6 (IL-6) and C-Reactive Protein (CRP) play an important role in chronic periodontitis with coronary artery disease (CAD). Genetic factors can affect a person's risk of CAD, which affects one-third of the population. This study investigated the role of IL-6 -572 C/G, CRP -757 A/G, and CRP -717 T/C gene polymorphisms. IL-6 and CRP levels on the severity of periodontitis in CAD in Indonesia were also evaluated. This case-control study was conducted with mild and moderate-severe chronic periodontitis groups. A path analysis test was conducted with Smart PLS with a 95% confidence interval to determine the significant variable for chronic periodontitis. Our study revealed that the effects of IL-6 -572 C/G, CRP -757 A/G, and CRP -717 T/C gene polymorphisms on IL-6 levels and CRP levels were not significant. IL-6 and CRP levels were not significantly different between the two groups. We found that IL-6 levels had a significant effect on CRP levels in periodontitis patients with CAD (path coefficient 0.322, p = 0.003). IL-6 -572 C/G, CRP -757 A/G, and CRP -717 T/C gene polymorphisms had no effect on the severity of chronic periodontitis in CAD patients in the Indonesian population. We also observed no apparent effects of the influence of gene polymorphisms in IL-6 -572 C/G, CRP -757 A/G, and CRP -717 T/C genes. Although the IL-6 and CRP levels were not significantly different between the two groups, IL-6 levels affected CRP levels in periodontitis patients with CAD.

Gingival crevicular fluid periodontal ligament-associated protein-1, sclerostin, and tumor necrosis factor-alpha levels in periodontitis.

BACKGROUND: In periodontitis, the equilibrium between bone formation and resorption skews in favor of bone loss. Periodontal ligament-associated protein-1 (PLAP-1) and sclerostin play a significant role in the suppression of bone formation. Tumor necrosis factor-alpha (TNF-α) is a central proinflammatory cytokine related to periodontal bone loss. This study aims to assess gingival crevicular fluid (GCF) PLAP-1, sclerostin, and TNF-α levels in individuals with periodontal disease. METHODS: Seventy-one individuals diagnosed with generalized stage III grade C periodontitis (n = 23), gingivitis (n = 24), and periodontal health (n = 24) were included in the study. Full-mouth clinical periodontal measurements were performed. PLAP-1, sclerostin, and TNF-α total amounts in GCF were quantified by ELISA. Nonparametric methods were used for the data analyses. RESULTS: Periodontitis group exhibited significantly higher GCF PLAP-1, sclerostin and TNF-α levels compared with gingivitis and periodontally healthy groups (p < 0.05). GCF PLAP-1 and TNF-α levels of gingivitis group were higher than healthy controls (p < 0.05) whereas GCF sclerostin levels were similar in two groups (p > 0.05). Significant positive correlations were found between GCF PLAP-1, sclerostin and TNF-α levels and all clinical parameters (p < 0.01). CONCLUSIONS: To our knowledge, this is the first study showing GCF PLAP-1 levels in periodontal health and disease. Increased GCF PLAP-1 and sclerostin levels and their correlations with TNF-α in periodontitis imply that those molecules might be involved in the pathogenesis of periodontal disease. Further studies in larger mixed cohorts are needed to enlighten the possible role of PLAP-1 and sclerostin in periodontal bone loss.

Immune infiltration and diagnostic value of immune-related genes in periodontitis using bioinformatics analysis.

BACKGROUND AND OBJECTIVES: Periodontitis, which is a chronic inflammatory periodontal disease resulting in destroyed periodontal tissue, is the leading cause of tooth loss in adults. Many studies have found that inflammatory immune responses are involved in the risk of periodontal tissue damage. Therefore, we analyzed the association between immunity and periodontitis using bioinformatics methods to further understand this disease. MATERIALS AND METHODS: First, the expression profiles of periodontitis and healthy samples were downloaded from the GEO database, including a training dataset GSE16134 and an external validation dataset GSE10334. Then, differentially expressed genes were identified using the limma package. Subsequently, immune cell infiltration was calculated by using the CIBERSORT algorithm. We further identified genes linking periodontitis and immunity from the ImmPort and DisGeNet databases. In addition, some of them were selected to construct a diagnostic model via a logistic stepwise regression analysis. RESULTS AND CONCLUSIONS: Two hundred sixty differentially expressed genes were identified and found to be involved in responses to bacterial and immune-related processes. Subsequently, immune cell infiltration analysis demonstrates significant differences in the abundance of most immune cells between periodontitis and healthy samples, especially in plasma cells. These results suggested that immunity doses play a non-negligible role in periodontitis. Twenty-one genes linking periodontitis and immunity were further identified. And nine hub genes of them were identified that may be key genes involved in the development of periodontitis. Gene ontology analyses showed that these genes are involved in response to molecules of bacterial origin, cell chemotaxis, and response to chemokines. In addition, three genes of them were selected to construct a diagnostic model. And its good diagnostic performance was demonstrated by the receiver operating characteristic curves, with an area under the curve of 0.9424 for the training dataset and 0.9244 for the external validation dataset.

Identification of abnormally methylated differentially expressed genes in chronic periodontitis by integrated bioinformatics analysis.

BACKGROUND: DNA methylation plays a vital role as an epigenetic change that contributes to chronic periodontitis. OBJECTIVE: This study aimed to integrate two methylation datasets (GSE173081 and GSE59962) and two gene expression datasets (GSE10334 and GES16134) to identify abnormally methylated differentially expressed genes related to chronic periodontitis. METHODS: Differentially methylated genes were obtained. Functional enrichment analysis of DMGs was performed. The protein-protein interaction (PPI) network was constructed using STRING and Cytoscape software. Finally, the hub genes were selected from the PPI network by using CytoHubba. RESULTS: In total, 122 hypomethylated and highly expressed genes were enriched in the biological mechanisms that are involved in the differentiation of extracellular matrix organization, extracellular structure organization, and cell chemotaxis. The three selected hub genes of the PPI network were IL1B, KDR, and MMP9. A total of 122 hypermethylated and lowly expressed genes were identified, and biological processes, such as cornification, epidermis development, skin development, and keratinocyte differentiation were enriched. CDSN DSG1, and KRT2 were identified as the top 3 hub genes of the PPI network. CONCLUSION: Based on the comprehensive bioinformatics analysis, six hub genes (IL1B, KDR, MMP9, CDSN DSG1, and KRT2) were associated with chronic periodontitis. Our findings provide novel insights into the mechanisms underlying epigenetic changes in chronic periodontitis.

Downregulation of miRNA-26 in chronic periodontitis interferes with innate immune responses and cell migration by targeting phospholipase C beta 1.

AIM: To evaluate the potential role of miR-26 family members in periodontal pathogenesis by assessing innate immune responses to periopathic bacteria and regulation of cytoskeletal organization. MATERIALS AND METHODS: Expression of miR-26a-5p and miR-26b-5p was quantified in gingival biopsies derived from healthy and periodontally diseased subjects before and after non-surgical (scaling and root planing) therapy by RT-qPCR. Global pathway analysis and luciferase assays were performed for target identification and validation. Cytokine expression was assessed in miR-26a-5p transfected human oral keratinocytes upon stimulation with either live Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans or Pg lipopolysaccharide (LPS). Wound closure assays were performed in cells transfected with miR-26a-5p, while the impact on cytoskeletal organization was assessed by F-actin staining. RESULTS: miR-26a-5p and miR-26b-5p were downregulated in diseased gingiva and restored 4-6 weeks post-therapy to levels comparable with healthy subjects. Target validation assays identified phospholipase C beta 1 as a bona fide novel target exhibiting antagonistic expression pattern in disease and post-therapy cohorts. miR-26a-5p transfected cells secreted higher levels of cytokine/chemokines upon stimulation with periopathogens and demonstrated impaired cell migration and cytoskeletal rearrangement. CONCLUSIONS: Downregulated miR-26a-5p levels in periodontal inflammation may interfere with key cellular functions that may have significant implications for host defence and wound healing.

Codon Pattern and Compositional Constraints Determination of Genes Associated with Chronic Periodontitis.

Genome-wide association studies showed the relationship of NIN, ABHD12B, WHAMM, AP3B2, and SIGLEC5 with chronic periodontitis. The study's objective was to investigate different molecular patterns and evolutionary forces acting on the mentioned genes. The investigation of molecular patterns encompasses the study of compositional parameters, expression profile, physical properties of genes, codon preferences, degree of codon bias, determination of the most influential codons, and assessment of actions of evolutionary forces, such as mutations and natural selection. The overall compositional analysis revealed the dominance of A and G nucleotides compared to T and C. A relatively low codon usage bias is observed. The CTG codon is the most overused codon, followed by TCC. The genes, AP3B2 and SIGLEC5, preferred GC-ending codons, while NIN, ABHD12B, and WHAMM preferred AT-ending codons. The presence of directional mutational force and natural selection was found to operate codon usage in genes envisaged, and selective forces were dominant over mutational forces. Apart from mutation and selection forces, compositional constraints also played imperative roles. The study enriched our knowledge of specific molecular patterns associated with the set of genes significantly associated with chronic periodontitis. Further studies are warranted to identify more genetic signatures associated with the disease.

Single-cell RNA sequencing reveals rebalancing of immunological response in patients with periodontitis after non-surgical periodontal therapy.

BACKGROUND: Periodontitis is a major inflammatory disease of the oral mucosa that is not limited to the oral cavity but also has systemic consequences. Although the importance of chronic periodontitis has been emphasized, the systemic immune response induced by periodontitis and its therapeutic effects remain elusive. Here, we report the transcriptomes of peripheral blood mononuclear cells (PBMCs) from patients with periodontitis. METHODS: Using single-cell RNA sequencing, we profiled PBMCs from healthy controls and paired pre- and post-treatment patients with periodontitis. We extracted differentially expressed genes and biological pathways for each cell type and calculated activity scores reflecting cellular characteristics. Intercellular crosstalk was classified into therapy-responsive and -nonresponsive pathways. RESULTS: We analyzed pan-cellular differentially expressed genes caused by periodontitis and found that most cell types showed a significant increase in CRIP1, which was further supported by the increased levels of plasma CRIP1 observed in patients with periodontitis. In addition, activated cell type-specific ligand-receptor interactions, including the BTLA, IFN-γ, and RESISTIN pathways, were prominent in patients with periodontitis. Both the BTLA and IFN-γ pathways returned to similar levels in healthy controls after periodontal therapy, whereas the RESISTIN pathway was still activated even after therapy. CONCLUSION: These data collectively provide insights into the transcriptome changes and molecular interactions that are responsive to periodontal treatment. We identified periodontitis-specific systemic inflammatory indicators and suggest unresolved signals of non-surgical therapy as future therapeutic targets.

Evaluation of P53 protein expression in gingival tissues of patients with chronic periodontitis by immunohistochemistry methods.

OBJECTIVE: Periodontitis is one of the most important periodontal diseases that can be affected by many factors. Although the mechanism of periodontitis development is not yet fully understood, previous studies suggest that apoptosis may be one of the pathological factors that can affect the process of the disease by destroying old and damaged cells. Low expression of P53 protein is one of the reasons for delaying cell death that allows damaged cells to survive longer and gives more time for the chance of mutations and pathogenesis. Because of the important role of P53 in gingival cells of patients with chronic periodontitis, the objective of our study is to evaluate the P53 protein expression in gingival tissues of patients with chronic periodontitis by immunohistochemistry methods. MATERIALS AND METHODS: In this cross-sectional study, 35 patients with severe to moderate chronic periodontitis (loss of attachment ≥3 mm, probing depth ≥5 mm) with no treatment and 25 people who were healthy for periodontal problems were examined. Gingival biopsies from marginal and attached gingiva were obtained, prepared, and mounted on slides. Then, the expression of P53 on each slide was evaluated by optic microscopy after using P53 antibodies and staining with hematoxylin-eosin (immunohistochemistry method). Data were analyzed using independent t-test, Mann-Whitney U-test, and Spearman correlation test using SPSS Statistics version 18.0. RESULTS: The mean ages of participants in the case and control groups were 37.58 and 32.09, respectively. Our results showed that the expression of P53 was not significant in periodontitis compared to the control group (p > .05). Also, gender could not affect the expression of P53 in both groups (p > .05), and there was no significant relationship between age and P53 gene incidence. CONCLUSION: Chronic periodontitis has no significant effect on P53 expression, so changes in apoptosis due to P53 expression in periodontitis are not significant.

Expression of periodontitis susceptibility genes in human gingiva using single-cell RNA sequencing.

OBJECTIVE: Single-cell transcriptomics was used to determine the possible cell-type specificity of periodontitis susceptibility genes. BACKGROUND: The last decade has witnessed remarkable advances in the field of human genomics. Despite many advances, the genetic factors associated with or contributing to the periodontitis pathogenesis have only been identified to a limited extent and are often poorly validated. Confirming whether a given single nucleotide polymorphism has an association with periodontitis requires a robust mechanistic explanation on the functional consequences of a given genetic variant. METHODS: We globally assessed the expression of 26 disease-associated genes identified by GWAS within the gingival mucosa. A total of 12 411 cells from 4 different donors were analysed. Differentially expressed genes were analysed using Seurat, a non-parametric Wilcoxon rank sum test. The minimum threshold for significance was defined as p < .05. RESULTS: This exploration at a cellular-level suggests diverse populations contributing to disease pathogenesis, with macrophages expressing a higher number of the analysed disease-associated genes. IL1B, PTGS2, FCGR2A, IL10 and IL1A specifically showed a more restricted expression in the myeloid lineages. CONCLUSION: This short report combines human genetics and single-cell genomics to better understand periodontitis by mapping variants to predict their cells of action and putative functions. These findings seem to suggest that innate cell dysfunction is linked to disease susceptibility.

Transcriptomic analysis reveals pathophysiological relationship between chronic obstructive pulmonary disease (COPD) and periodontitis.

BACKGROUND: The aim of this study was to detect potential crosstalk genes, pathways and immune cells between periodontitis and chronic obstructive pulmonary disease (COPD). METHODS: Chronic periodontitis (CP, GSE156993) and COPD (GSE42057, GSE94916) datasets were downloaded. Differential expressed genes (DEGs; p < 0.05) were assessed and screened for overlapping results, following functional pathway enrichment analyses (p < 0.05). The xCell method was used to assess immune cell infiltration relationship between CP and COPD. Features of the detected cross-talk genes were revealed using conventional Recursive Feature Elimination (RFE) algorithm in R project. Receiver-operating characteristic curves were applied to evaluate the predictive value of the genes. Furthermore, Pearson correlation analysis was performed on crosstalk markers and infiltrating immune cells in CP and COPD, respectively. RESULTS: A total of 904 DEGs of COPD and 763 DEGs of CP were acquired, showing 22 overlapping DEGs between the two diseases. Thereby 825 nodes and 923 edges were found in the related protein-protein-interaction network. Eight immune cell pairs were found to be highly correlated to both CP and COPD (|correlation coefficients |> 0.5 and p-value < 0.05). Most immune cells were differently expressed between COPD and CP. RFE identified three crosstalk genes, i.e. EPB41L4A-AS1, INSR and R3HDM1. In correlation analysis, INSR was positively correlated with Hepatocytes in CP (r = 0.6714, p = 0.01679) and COPD (r = 0.5209, p < 0.001). R3HDM was positively correlated with Th1 cells in CP (r = 0.6783, p = 0.0153) and COPD (r = 0.4120, p < 0.01). CONCLUSION: EPB41L4A-AS1, INSR and R3HDM1 are potential crosstalk genes between COPD and periodontitis. R3HDM was positively correlated with Th1 cells in both diseases, while INSR was positively correlated with Hepatocytes in periodontitis and COPD, supporting a potential pathophysiological relationship between periodontitis and COPD.

Periodontal disease progression and gene polymorphisms: results after 3 years of active periodontal treatment.

BACKGROUND: Although non-surgical periodontal treatment is considered the gold standard, a subgroup of patients displays recurrence/progression of periodontitis after treatment. The aim of the present prospective study was to assess the effect of IL-6 -572 G/C and IL-10 -592 C/A gene polymorphisms on the risk of disease recurrence/progression at 3 years following non-surgical periodontal treatment. METHODS: Thirty-seven patients diagnosed with chronic periodontitis received oral hygiene instructions and non-surgical periodontal treatment and were monitored for 3 years. All individuals were clinically evaluated for PPD, CAL and BOP at baseline and 3 years. Based on the clinical findings at 3 years, all subjects were considered either "at risk" or "not at risk" of periodontal disease progression based on specific criteria. Blood samples were collected at baseline and genotyping of the polymorphisms in IL-6 (rs1800796) and IL-10 (rs1800872) genes were performed by PCR. RESULTS: Following DNA separation and genotyping, 70.3% of the patients were homozygous carriers of the IL-6 -572G and 45.9% were carriers of the IL-10 -592A allele. Individuals at risk of disease progression ranged from 16.2% to 56.8% based on the criteria used. IL-6 -572 G/C and IL-10 -592 C/A polymorphisms were not associated with an increased risk of further disease progression (P>0.05) when the three criteria were examined. All examined periodontal clinical measures were significantly improved (P<0.05) after treatment. Males showed a significantly higher risk of disease progression than females when full-mouth BOP ≥30% was considered (P=0.008). CONCLUSIONS: Within the limitations of this 3-year prospective study, individuals susceptible to periodontal disease as determined by the presence of the IL-6 -572GG genotype or the IL-10 -592A allele were not associated with an increased risk of further disease progression and the potential need for further treatment following non-surgical periodontal treatment. Males were more prone to be at risk of disease progression than females.

Analysis of GLT6D1 and CDKN2BAS gene polymorphisms in Brazilian patients with advanced periodontitis.

Gene polymorphisms can predispose to periodontal disease, as demonstrated by the well-documented association between aggressive periodontitis and single nucleotide polymorphisms (SNPs) such as rs153745 in the GLT6D1 gene and rs3217992 in the CDKN2BAS gene. The purpose of this study was to evaluate the presence of these SNPs in Brazilian patients with advanced periodontitis (stages III/IV, Grade B/C) vs. healthy controls. A total of 100 patients with periodontitis (Group BC) were enrolled. Of these, 51 patients were classified as stage III and 49 patients were classified as stage IV, and 52 were Grade B (Group B) and 48 were Grade C (Group C). The control Group consisted of 61 healthy subjects. DNA samples extracted from buccal epithelial cells were used to genotype the SNPs rs1537415 (GLT6D1) and rs3217992 (CDKN2BAS) by real-time quantitative PCR. No significant differences in polymorphism frequency were found between the control Group and each of the patient groups (BC, B, or C), and Group B did not differ from Group C. In conclusion, the evaluated SNPs had no significant influence on the prevalence of periodontal disease in the sampled Brazilian population.