Background
Infection and inflammation induce epigenetic changes that alter gene expression. In periodontal disease, inflammation, and microbial dysbiosis occur, which can lead to compromised barrier ...function of the gingival epithelia. Here, we tested the hypotheses that infection of cultured human gingival epithelial (HGEp) cells with Porphyromonas gingivalis disrupts barrier function by inducing epigenetic alterations and that these effects can be blocked by inhibitors of DNA methylation.
Methods
Primary HGEp cells were infected with P. gingivalis either in the presence or absence of the non‐nucleoside DNA methyltransferase (DNMT) inhibitors RG108, (–) epigallocatechin‐3‐gallate (EGCG), or curcumin. Barrier function was assessed as transepithelial electrical resistance (TEER). DNA methylation and mRNA abundance were quantified for genes encoding components of three cell‐cell junction complexes, CDH1, PKP2, and TJP1. Cell morphology and the abundance of cell‐cell junction proteins were evaluated by confocal microscopy.
Results
Compared to non‐infected cells, P. gingivalis infection decreased TEER (P < 0.0001) of HGEp cells; increased methylation of the CDH1, PKP2, and TJP1 (P < 0.0001); and reduced their expression (mRNA abundance) (P < 0.005). Pretreatment with DNMT inhibitors prevented these infection‐induced changes in HGEp cells, as well as the altered morphology associated with infection.
Conclusion
Pathogenic infection induced changes in DNA methylation and impaired the barrier function of cultured primary gingival epithelial cells, which suggests a mechanism for systemic consequences of periodontal disease. Inhibition of these events by non‐nucleoside DNMT inhibitors represents a potential strategy to treat periodontal disease.
Background. Type 2 diabetes mellitus (T2DM) and periodontitis (P) commonly occur as comorbidities, but the commonalities in the genetic makeup of affected individuals is largely unknown. Since ...dyslipidemia is a frequent condition in these individuals, we investigate the association of genomic variations in genes involved in lipid metabolism with periodontal, glycemic, lipid profiles, and the association with periodontitis and T2DM (as comorbidities). Methods. Based on clinical periodontal examination and biochemical evaluation, 893 subjects were divided into T2DM+P (T2DM subjects also affected by periodontitis, n=205), periodontitis (n=345), and healthy (n=343). Fourteen single-nucleotide polymorphisms (SNPs) were investigated: LDLR gene (rs5925 and rs688), APOB (rs676210, rs1042031, and rs693), ABCC8 (rs6544718 and 6544713), LPL (rs28524, rs3735964, and rs1370225), HNF1A (rs2650000), APOE (rs429358 and rs7412), and HNF4A (rs1800961). Multiple linear and logistic regressions (adjusted for covariates) were made for all populations and stratified by sex and smoking habits. Results. Individuals carrying APOB-rs1042031-CT (mainly women and never smokers) had a lower risk of developing periodontitis and T2DM (T2DM+P); altogether, this genotype was related with healthier glycemic, lipid, and periodontal parameters. Significant disease-phenotype associations with gene-sex interaction were also found for carriers of APOB-rs1676210-AG, HNF4A-rs1800961-CT, ABCC8-rs6544718-CT, LPL-rs13702-CC, and LPL-rs285-CT. Conclusions. Polymorphisms in lipid metabolism genes are associated with susceptibility to T2DM-periodontitis comorbidities, demonstrating gene-sex interaction. The APOB-rs1042031 was the most relevant gene marker related to glucose and lipid metabolism profiles, as well as with obesity and periodontitis.
Objective
Genome-wide association studies (GWAS) and literature have identified polymorphisms in the
KCNJ11
,
HNF1A
,
IRS1
,
TCF7L2
,
CDKAL1
,
CDKN2B
,
RPSAP52
,
GPR45 HHEX
,
IL18
, and
RUNX2
genes ...associated with type 2 diabetes mellitus (T2DM) and/or periodontitis (P) in diverse populations, and we sought to evaluate them as genetic risk variants for these diseases in the Brazilian population.
Material and methods
Periodontal, glycemic, and lipid data were obtained from 931 individuals divided into: control (
n
= 334), periodontitis (P;
n
= 358), and periodontitis associated with T2DM (P + T2DM;
n
= 239). After genotyping, associations between polymorphisms and pathologies were tested by multiple logistic and linear regressions, adjusting for age, sex, and smoking habits.
Results
Considering the studied subjects, the increased risk to develop periodontitis in the periodontitis P + T2DM group was found for
HNF1A-
rs7957197-TA,
CDKAL1-
rs7754840-CG,
RPSAP52
-rs1531343-GC,
TCF7L2
-rs7903146-TT, and
CDKN2B
-rs7018475-GG. The association of these genetic variants for
TCF7L2
and
CDKN2B
was confirmed for female, never smokers, and poorly controlled P + T2DM.
CDKN2B
-rs7018475 was associated with worse glycemic condition and periodontal parameters.
Conclusion
These five reported genetic variants were associated in the studied Southeastern Brazilian population as genetic risk variants of periodontitis and T2DM associated to periodontitis as comorbidity. Gene–phenotype associations with sex and smoking habits and the
CDKN2B-
rs7018475 with the poor glycemic control and more severe periodontal conditions should be further investigated.
Clinical relevance
Polymorphisms in the
CDKAL1-
rs7754840,
HNF1A-
rs7957197,
RPSAP52
-rs1531343,
TCF7L2
-rs7903146, and
CDKN2B-
rs7018475 might predispose to periodontitis and T2DM associated with periodontitis. These findings may be useful in public health genomics and future advanced clinical practice, since genetic carriage can be measured before disease onset, being of potential great benefit for treatment planning and prognosis in early disease stages.
Type 2 diabetes mellitus (T2DM), dyslipidemia and periodontitis are frequently associated pathologies; however, there are no studies showing the peripheral blood transcript profile of these combined ...diseases. Here we identified the differentially expressed genes (DEGs) of circulating lymphocytes and monocytes to reveal potential biomarkers that may be used as molecular targets for future diagnosis of each combination of these pathologies (compared to healthy patients) and give insights into the underlying molecular mechanisms of these diseases. Study participants (n = 150) were divided into groups: (H) systemically and periodontal healthy (control group); (P) with periodontitis, but systemically healthy; (DL-P) with dyslipidemia and periodontitis; (T2DMwell-DL-P) well-controlled type 2 diabetes mellitus with dyslipidemia and periodontitis; and (T2DMpoorly-DL-P) poorly-controlled type 2 diabetes mellitus with dyslipidemia and periodontitis. We preprocessed the microarray data using the Robust Multichip Average (RMA) strategy, followed by the RankProd method to identify candidates for DEGs. Furthermore, we performed functional enrichment analysis using Ingenuity Pathway Analysis and Gene Set Enrichment Analysis. DEGs were submitted to pairwise comparisons, and selected DEGs were validated by quantitative polymerase chain reaction. Validated DEGs verified from T2DMpoorly-DL-P versus H were: TGFB1I1, VNN1, HLADRB4 and CXCL8; T2DMwell-DL-P versus H: FN1, BPTF and PDE3B; DL-P versus H: DAB2, CD47 and HLADRB4; P versus H: IGHDL-P, ITGB2 and HLADRB4. In conclusion, we identified that circulating lymphocytes and monocytes of individuals simultaneously affected by T2DM, dyslipidemia and periodontitis, showed an altered molecular profile mainly associated to inflammatory response, immune cell trafficking, and infectious disease pathways. Altogether, these results shed light on novel potential targets for future diagnosis, monitoring or development of targeted therapies for patients sharing these conditions.
Background: Tumor necrosis factor‐α (TNF‐α) plays a central role in the molecular pathogenesis of periodontal disease. However, the epigenetic regulation attributable to microbial and inflammatory ...signals at the biofilm–gingival interface are poorly understood. In this study, the DNA methylation alteration within the TNFA promoter in human gingival biopsies from different stages of periodontal disease is investigated and the regulatory mechanism of TNFA transcription by DNA methylation is explored.
Methods: Gingival biopsies were obtained from 17 patients with chronic periodontitis (CP) and 18 periodontally healthy individuals. Another 11 individuals participated in an experimentally induced gingivitis study, and gingival biopsies were collected at the baseline, induction, and resolution phase. To confirm that TNFA promoter methylation modulated TNFA transcription, THP.1 cells were treated with a DNA methyltransferase inhibitor, 5‐Aza‐2‐deoxycytidine (5‐Aza‐2dC), and an RAW294.7 cell line transfected with a TNFA promoter‐specific luciferase reporter system with or without methylation was used.
Results: In gingival biopsies from individuals with severe CP, two individual cytosine‐guanine dinucleotides (CpG sites) within the TNFA promoter (at −163 and −161 bp) displayed increased methylation in CP samples compared to those with gingival health (16.1% ± 5.1% versus 11.0% ± 4.6%, P = 0.02 and 19.8% ± 4.1% versus 15.4% ± 3.6%, P = 0.04, respectively). The methylation level at −163 bp was inversely associated with the transcription level of TNFA (P = 0.018). However, no significant difference in the TNFA promoter methylation pattern was observed in samples biopsied during the induction or resolution phase of experimentally induced gingivitis, which represented a reversible periodontal lesion. THP.1 cells treated with 5‐Aza‐2dC demonstrated a time‐dependent increase in TNFA messenger level. It was also found that the luciferase activity decreased 2.6‐fold in a construct containing an in vitro methylated TNFA promoter when compared to the unmethylated insert (P = 0.03).
Conclusion: Although the biopsy samples represented a mixed cell population, the change in promoter methylation status in chronic periodontal disease suggested that DNA methylation may be an important regulatory mechanism in controlling TNFA transcriptional expression in periodontal disease.
Chronic periodontitis (CP) is a common oral disease that confers substantial systemic inflammatory and microbial burden and is a major cause of tooth loss. Here, we present the results of a ...genome-wide association study of CP that was carried out in a cohort of 4504 European Americans (EA) participating in the Atherosclerosis Risk in Communities (ARIC) Study (mean age-62 years, moderate CP-43% and severe CP-17%). We detected no genome-wide significant association signals for CP; however, we found suggestive evidence of association (P < 5 × 10(-6)) for six loci, including NIN, NPY, WNT5A for severe CP and NCR2, EMR1, 10p15 for moderate CP. Three of these loci had concordant effect size and direction in an independent sample of 656 adult EA participants of the Health, Aging, and Body Composition (Health ABC) Study. Meta-analysis pooled estimates were severe CP (n = 958 versus health: n = 1909)-NPY, rs2521634 G: odds ratio OR = 1.49 (95% confidence interval (CI = 1.28-1.73, P = 3.5 × 10(-7))); moderate CP (n = 2293)-NCR2, rs7762544 G: OR = 1.40 (95% CI = 1.24-1.59, P = 7.5 × 10(-8)), EMR1, rs3826782 A: OR = 2.01 (95% CI = 1.52-2.65, P = 8.2 × 10(-7)). Canonical pathway analysis indicated significant enrichment of nervous system signaling, cellular immune response and cytokine signaling pathways. A significant interaction of NUAK1 (rs11112872, interaction P = 2.9 × 10(-9)) with smoking in ARIC was not replicated in Health ABC, although estimates of heritable variance in severe CP explained by all single nucleotide polymorphisms increased from 18 to 52% with the inclusion of a genome-wide interaction term with smoking. These genome-wide association results provide information on multiple candidate regions and pathways for interrogation in future genetic studies of CP.
This study aimed to investigate polymorphisms in genes considered molecular biomarkers of type 2 diabetes mellitus (T2DM) to assess whether they are associated with periodontitis, and relating them ...to the periodontal status, glycemic and lipid profile of the subjects.
We investigated individuals who underwent complete periodontal examination and biochemical evaluation. We categorized them into three groups: (i) periodontitis with T2DM (Periodontitis+T2DM group, n = 206); (ii) periodontitis without T2DM (Periodontitis group, n = 346); and (iii) healthy individuals without Periodontitis or T2DM (Healthy group, n = 345). We investigated three single nucleotide polymorphisms (SNPs) for AGER, RBMS1 and VEGFA genes. We applied multivariate logistic and multiple linear regression models for all groups and stratified the subjects by sex and smoking habits.
Compared with RBMS1-rs7593730-CC+CT genotype carriers, RBMS1-rs7593730-TT carriers were more susceptible to periodontitis odds ratio (OR) = 2.29; 95% confidence interval (CI) = 1.04–5.01; P-value = 0.033. Among AGER-rs184003-CC carriers, never smokers had reduced risks of periodontitis and Periodontitis+T2DM than ever smokers. For either RBMS1-rs7593730-CC or VEGFA-rs9472138-CC carriers, never smokers had less susceptibility to develop periodontitis than ever smokers. Compared with AGER-rs184003-CC carriers, AGER-rs184003-AA carriers presented fewer remaining teeth. VEGFA-rs9472138-TT carriers showed a lower percentage of sites with characteristics of active periodontal disease (bleeding on pocket probing and interproximal clinical attachment level) compared with VEGFA-rs9472138-CC carriers.
In the studied population, AGER rs184003, RBMS1 rs7593730, and VEGFA rs9472138, which are considered genetic markers for T2DM, were associated with periodontitis without T2DM or periodontitis together with T2DM.
•Risk genes of type 2 diabetes mellitus (T2DM) are associated with periodontitis.•Never smoker AGER CC carriers had a lower risk of periodontitis or periodontitis+T2DM.•Never smoker RBMS1 and VEGFA CC carriers had a lower risk of periodontitis.•AGER-rs184003-AA carriers presented fewer remaining teeth.•VEGFA TT carriers had fewer sites with characteristics of active periodontitis.
Genome-wide association studies (GWAS) of chronic periodontitis (CP) defined by clinical criteria alone have had modest success to-date. Here, we refine the CP phenotype by supplementing clinical ...data with biological intermediates of microbial burden (levels of eight periodontal pathogens) and local inflammatory response (gingival crevicular fluid IL-1β) and derive periodontal complex traits (PCTs) via principal component analysis. PCTs were carried forward to GWAS (∼2.5 million markers) to identify PCT-associated loci among 975 European American adult participants of the Dental ARIC study. We sought to validate these findings for CP in the larger ARIC cohort (n = 821 participants with severe CP, 2031-moderate CP, 1914-healthy/mild disease) and an independent German sample including 717 aggressive periodontitis cases and 4210 controls. We identified six PCTs with distinct microbial community/IL-1β structures, although with overlapping clinical presentations. PCT1 was characterized by a uniformly high pathogen load, whereas PCT3 and PCT5 were dominated by Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, respectively. We detected genome-wide significant signals for PCT1 (CLEC19A, TRA, GGTA2P, TM9SF2, IFI16, RBMS3), PCT4 (HPVC1) and PCT5 (SLC15A4, PKP2, SNRPN). Overall, the highlighted loci included genes associated with immune response and epithelial barrier function. With the exception of associations of BEGAIN with severe and UBE3D with moderate CP, no other loci were associated with CP in ARIC or aggressive periodontitis in the German sample. Although not associated with current clinically determined periodontal disease taxonomies, upon replication and mechanistic validation these candidate loci may highlight dysbiotic microbial community structures and altered inflammatory/immune responses underlying biological sub-types of CP.
Objective
To assess whether single nucleotide polymorphisms (SNPs) in the IL10, IL1A, IL1B, IL4, TNFA, IL6, OPG, RANK, and RANKL genes, “classically” related with periodontitis, could be associated ...with susceptibility to T2DM, and also with both diseases concomitantly.
Background
There are common pathogenic mechanisms in type 2 diabetes mellitus (T2DM) and periodontitis, but the knowledge of the genetic aspect of this is limited. In patients affected by concomitant T2DM and periodontitis, whose incidence is increasing, there is scarce information regarding the gene‐phenotype association, including whether there are genes able to influence both diseases as comorbidities.
Methods
Periodontal clinical parameters and biochemical profile (Insulin, Fasting Glycemia, HbA1c, Triglycerides, Total Cholesterol, HDL‐cholesterol, and LDL‐cholesterol) data were obtained from 894 individuals divided into following three groups: Healthy (H; n = 347), Periodontitis (P; n = 348), and Periodontitis + T2DM (P + T2DM; n = 199). DNA from oral epithelial cells was collected for genotyping. Associations between SNPs and pathologies were tested by multiple logistic regression models, adjusting for age, sex, and smoking habits. We also investigated whether there are sex or smoking effects of each SNP in these phenotypes.
Results
The rs1143634‐GA (IL1B) SNP showed significantly less likely to develop P + T2DM for all population and mainly for women (adjusted OR = 0.37, 95% CI = 0.16‐0.88), while women carrying the rs224320 CT (IL4) were more susceptible to develop P + T2DM (adjusted OR = 1.81, 95% CI = 1.04‐3.15). Men carrying the rs1800795‐CC (IL6) genotype were less likely to develop T2DM (adjusted OR = 0.12, 95% CI = 0.02‐0.70, P = .01).
Conclusions
Some SNPs in the IL1B, IL4, and IL6 genes demonstrated sex‐influenced association with concomitant periodontitis and T2DM, increasing the evidence of a common genetic component between these diseases and contributing with the understanding of their common pathogenic mechanisms.
Few studies evaluate interrelationships between periodontitis (P) and Type 2 Diabetes Mellitus (T2DM). The aim of this study is to investigate the genetic susceptibility to periodontitis alone, or ...concomitant with T2DM (as comorbidities), analyzing single nucleotide polymorphisms (SNPs) in the
Interleukin 17 alpha
(
IL17A
) gene, considering the biochemical profile and smoking habits on the subjects’ periodontal status. We investigated 879 individuals divided into: T2DM subjects also affected by severe or moderate periodontitis (T2DM-P,
n
= 199); non-diabetics with severe or moderate periodontitis (PERIODONTITIS,
n
= 342); and healthy subjects (HEALTHY,
n
= 338). Subjects underwent complete periodontal examination, history of smoking habits, glycemic and lipid biochemical evaluation. DNA from buccal cells was utilized to genotype the SNPs rs2275913, rs3819024 and rs10484879. The impact of the subjects’ biochemical profile was analyzed in their periodontal status. Each SNP was analyzed independently, and as haplotypes, by multiple logistic regressions, adjusted for covariates, and also stratifying the groups by age, sex and smoking habits. Independently of the periodontitis degree, poorly-controlled T2DM subjects showed worse glycemic and lipid profile. Multiple logistic regressions demonstrated that smokers and former-smokers carrying the GG genotype of rs3819024 seemed to have higher risk for T2DM-Periodontitis (OR = 6.33; 95% CI = 1.26–31.77,
p
= 0.02), and mainly for T2DM alone (OR = 5.11; 95% CI = 1.37–19.06,
p
= 0.01), than never smokers. We found the potential effect of smoking habits in the association of
IL17A
-rs3819024-GG with diseased phenotypes. Because the observed wide confidence intervals, further studies enrolling larger populations, and SNPs’ functional evaluations are needed to better understand our findings.
PDF
