Polymorphic regions in the interleukin-1 gene and susceptibility to chronic periodontitis: a genetic association study

Periodontal Treatment Reduces Circulating Pro-Inflammatory Cytokine and Chemokine Levels in African American HIV+ Individuals with Virological Suppression

Introduction

Periodontal Disease (PD), a chronic inflammatory disease, is highly prevalent among Persons Living With HIV (PLWH) and is characterized by microbial symbiosis and oxidative stress. Our hypothesis stipulates that periodontal therapy attenuates systemic inflammatory and bacterial burden while improving periodontal status in PLWH.

Methods

Sixteen African Americans (AA) with suppressed HIV viremia on long-term Antiretroviral Therapy (ART) were recruited to this study. Participants were placed into two groups, based on their dental care status: group 1 (In-Care, IC) and group 2 (Out of Care, OC). Periodontal health was investigated at baseline, 3 months, 6 months, and 12 months. Cytokine/chemokines, microbial phyla, and Asymmetric Dimethylarginine (ADMA, a marker for endothelial cell dysfunction) levels were assessed in the serum. Statistical comparisons between groups and at different visits were performed using multiple comparison tests.

Results

Across longitudinal visits, periodontal treatment significantly reduced the levels of several cytokines and chemokines. At baseline, the out of care group had significantly higher blood levels of ADMA and actinobacteria than the IC group. Periodontal treatment significantly altered the abundance of circulating genomic bacterial DNA for various phyla in out of care group.

Conclusions

Periodontal treatment interventions effectively attenuated circulating pro-inflammatory cytokines and altered microbial translocation, both critical drivers of systemic inflammation in PLWH.

A Systematic Review and Meta-Analysis on Multiple Cytokine Gene Polymorphisms in the Pathogenesis of Periodontitis

Aim

Periodontitis is an inflammatory disease that destroys both soft and hard periodontal tissues. However, a complex periodontal cytokine network remains unclear. This systematic review explored multiple cytokine gene polymorphisms in the pathogenesis of periodontitis.

Material and Methods

A systematic search was performed using the databases from previous publications, which indicated the association between cytokine polymorphisms and periodontitis pathogenesis. Meta-analysis was conducted using fixed or randomized models to calculate the significance of multiple cytokine polymorphisms. A total of 147 articles were analyzed with polymorphisms in 12 interleukins [Th1 (IL-2, IFN-γ, and TNF-α), Th2 (IL-4 and IL-13), Th17 (IL-1α, IL-1β, IL-6, and IL-17), and Treg cytokines (IL-10 and TGF-β)]. Doi plot was used to probe the occurrence of publication bias.

Results

The polymorphisms of IL-2 and TNF-α of Th1 cytokine family may be associated with the pathogenesis or the prevention of periodontitis risk, while the polymorphism of IFN-γ is not related to periodontitis risk. The polymorphisms for IL-4 and IL-13 of Th2 cytokine family are not found to be associated with the pathogenesis of periodontitis. For the polymorphisms of the members of Th17 cytokine family, different IL-1α polymorphisms may have inverse actions in the pathogenesis of periodontitis. IL-1β is a noteworthy cytokine biomarker in periodontitis development and progression. IL-6 may have a protective function in the inflammatory responses of periodontitis, and IL-17 has a weak relationship the inflammatory responses. The polymorphisms for the members of Treg cell cytokines may have a protective function against periodontitis risk. LFK indexes show the major asymmetry due to publication bias.

Conclusion

IL-1β is a notable cytokine biomarker in periodontitis risk. Treg cytokines favor an anti-inflammatory and protective environment. Further data are needed to confirm the present conclusion due to publication bias.

ILC1s and ILC3s Exhibit Inflammatory Phenotype in Periodontal Ligament of Periodontitis Patients

Innate lymphoid cells (ILCs) are emerging as important players in inflammatory diseases. The oral mucosal barrier harbors all ILC subsets, but how these cells regulate the immune responses in periodontal ligament tissue during periodontitis remains undefined. Here, we show that total ILCs are markedly increased in periodontal ligament of periodontitis patients compared with healthy controls. Among them, ILC1s and ILC3s, particularly NKp44⁺ILC3 subset, are the predominant subsets accumulated in the periodontal ligament. Remarkably, ILC1s and ILC3s from periodontitis patients produce more IL-17A and IFN-γ than that from healthy controls. Collectively, our results highlight the role of ILCs in regulating oral immunity and periodontal ligament inflammation and provide insights into targeting ILCs for the treatment of periodontitis.

Milk Kefir therapy reduces inflammation and alveolar bone loss on periodontitis in rats

Periodontitis is a chronic inflammatory disease that affects the tooth-supporting tissues. This study evaluated the anti-inflammatory and antiresorptive effects of milk kefir (MK) on periodontitis in rats. Micro-Raman spectroscopy was performed on MK at different fermentation times to verify the presence of Lactobacillus kefiri. From these results, Wistar rats were divided into the following groups: C (Control); EP (experimental periodontitis); K1 (animals that received MK with one day of fermentation); K1+EP; K4 (animals without EP using MK with four days of fermentation) and K4+EP. MK was administered 28 days before EP induction and during the disease development period (11 days). On day 28, in the EP groups, periodontitis was induced. The animals were euthanized on day 39. The hemimaxillae were removed and the following parameters were evaluated: micro-Raman analysis of the presence of inflammation; histomorphometric analysis to quantify alveolar bone loss and immunohistochemistry for IL-6, TNF-α, IL-Iβ and IL-10 in the periodontal ligament. Micro-Raman analysis showed that four days fermentation MK has a higher intensity spectrum of L. kefiri. Furthermore, the administration of this probiotic reduced the intensity of the inflammation spectrum when compared to one day fermentation MK. It was observed that the animals from the K4+EP group showed significant reduction of alveolar bone loss, as well as a lower IL-6, TNF-α and IL-Iβ immunoexpression and a higher IL-10 immunoexpression, when compared to EP groups. We conclude that MK has anti-inflammatory and antiresorptive effects on periodontitis in rats and that these effects are fermentation time dependent.

Definitions used for a healthy periodontium-A systematic review

OBJECTIVE

To investigate the explicitness and variability of the definition of periodontal health in the current scientific literature.

MATERIAL AND METHODS

The authors conducted a systematic literature review using PubMed and CENTRAL (2013-01/2019-05) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the guidelines of the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) statement.

RESULTS

A total of 51 papers met the predefined inclusion criteria. Of these, 13 papers did not report any explicit definitions of periodontal health. Out of the 38 remaining articles, half of them used a reference to support their definition and half of them not. The studies published in periodontics-related journals or those that scored a low risk of bias for the methodical quality presented more explicit and valid definitions. Probing pocket depth was the most frequently used individual parameter for defining periodontal health. However, there were substantial variations in the methods of measurement and cut-off values.

CONCLUSIONS

Given the diversity of periodontal health definitions, a cross-study comparison is difficult. The results of this review may be useful in making others aware of the significance of standardizing the definition of a healthy periodontium.

Influence of inflammasome NLRP3, and IL1B and IL2 gene polymorphisms in periodontitis susceptibility

The pathogenesis of periodontitis (PD) involves several molecules of the immune system that interact in a network to eliminate the periodontopathogens, yet, they contribute to periodontal tissue destruction. The different mechanisms that lead to periodontal tissue damage are not clear. Despite this, immune response genes have been related to the development of PD previously, such as those involved in inflammasomes which are multiprotein complexes and cytokines including Interleukin-1. The aim of the study was to evaluate the polymorphisms in NLRP3 inflammasome, cytokine and receptor of cytokines genes in the development of periodontitis. This case-control study was conducted in 186 patients with PD (stage II and III and grade B) and 208 controls (localized gingivitis and periodontally healthy individuals). Genotyping was performed using PCR-RFLP for the SNP rs4612666 in NLRP3 and using PCR-SSP for IL1A, IL1B, IL1R, IL1RN, IL4RA, INFG, TGFB1, TNF, IL2, IL4, IL6, and IL10. Cytokine serum levels were measured using Luminex technology. SNPStats and OpenEpi software were used to perform statistical analysis. The higher frequencies of NLRP3 T/C and IL1B -511 T/T genotypes and IL2 (+166, -330) GT haplotype were observed in patients with PD compared to controls. The SNPs in NLRP3, IL1R +1970, IL6–174, TNF -308, IL2 +166 and -330, TGFB1 +869 and +915, IL4RA +1902, IL4–1098 and -590 were associated to PD in men. In conclusion, polymorphisms in NLRP3, IL1B and IL2 genes were associated to PD susceptibility. Men carrying the NLRP3, IL1R, IL6, TNF, IL2, TGFB1, IL4RA and IL4 polymorphisms had greater susceptibility than women for developing PD.

Association between IL-1A (-889C/T) polymorphism and susceptibility of chronic periodontitis: A meta-analysis

OBJECTIVE

The purpose of this study was to investigate the association between IL-1A (-889C/T, rs1800587) polymorphism and susceptibility of chronic periodontitis.

METHODS

A systematic literature search was carried out in the databases updated on July 1, 2019, including PubMed, Embase, Cochrane Library and Web of Science. Through STATA 14.0 software, the association between IL-1A (-889C/T) polymorphism and susceptibility of chronic periodontitis was calculated by pooled odds rations (ORs) and 95% confidence intervals (CIs). Harbord test was used for the publication bias.

RESULTS

The results of overall meta-analysis revealed that IL-1A (-889C/T) polymorphism was associated with the susceptibility of chronic periodontitis among all the genetic models, including allele contrast [T vs. C, OR (95% CI): 1.297 (1.038-1.622), P = 0.022], dominant model [TT + CT vs. CC, OR (95% CI): 1.337 (1.015-1.761), P = 0.039], recessive model [TT vs. CC + CT, OR (95% CI): 1.453 (1.138-1.856), P = 0.003], and codominant model [TT vs. CC, OR (95% CI): 1.555 (1.187-2.038), P = 0.001; CT vs. CC, OR (95% CI): 2.559 (1.245-5.260), P = 0.011]. The results of subgroup analyses indicated that IL-1A (-889C/T) polymorphism was closely related to the susceptibility of chronic periodontitis in African population [T vs. C, OR (95% CI): 1.277 (1.039-1.571), P = 0.020; TT + CT vs. CC, OR (95% CI): 1.357 (1.061-1.735), P = 0.015; TT vs. CC, OR (95% CI): 1.599 (1.115-2.292), P = 0.011], in European population [TT vs. CC + CT, OR (95% CI): 1.645 (1.112-2.435), P = 0.013; TT vs. CC, OR (95% CI): 1.639 (1.044-2.574), P = 0.032] and in American population [CT vs. CC, OR (95% CI): 6.404 (3.000-13.669), P < 0.001].

CONCLUSIONS

IL-1A (-889C/T) polymorphism is associated with the susceptibility of chronic periodontitis in African, European and American populations according to the currently available evidence.

The cytokine network involved in the host immune response to periodontitis

Periodontitis is an inflammatory disease involving the destruction of both soft and hard tissue in the periodontal region. Although dysbiosis of the local microbial community initiates local inflammation, over-activation of the host immune response directly activates osteoclastic activity and alveolar bone loss. Many studies have reported on the cytokine network involved in periodontitis and its crucial and pleiotropic effect on the recruitment of specific immunocytes, control of pathobionts and induction or suppression of osteoclastic activity. Nonetheless, particularities in the stimulation of pathogens in the oral cavity that lead to the specific and complex periodontal cytokine network are far from clarified. Thus, in this review, we begin with an up-to-date aetiological hypothesis of periodontal disease and summarize the roles of cytokines in the host immune response. In addition, we also summarize the latest cytokine-related therapeutic measures for periodontal disease.

Identification of Periopathogenes from Dental Plaque in Periodontal Patients with PCR Technique and Their Association with Composite Interleukin-1 Genotype

INTRODUCTION

The present study aimed to assess the presence of main types of microorganisms involved in the aetiopathogenesis of chronic periodontitis with PCR technique and determinates the presence of composite IL-1 genotype and their associations with founded bacteria.

MATERIAL AND METHOD

The examined group was consisted from 20 subjects with diagnosed chronic periodontitis and 20 healthy control without periodontitis. Clinical parameters like gingival index (GI), plaque index (PI), bleeding on probing (BOP), periodontal pocket depth (PPD) and clinical attachment lost (CAL) were determinates. Subgingival dental plaque was collected using a sterilized paper point. We used Parodontose Plus test, reverse hybridization kit, for the detection of periodontal marker bacteria, as well as for the detection of composite Interleukin -1 Genotype Results: The most present bacterial species detected from subgingival dental plaque was Treponema denticola and Porfiromonas gingivalis which was present in 65% of examined patients. In relation to the presence of positive genotype in patients, there was no significant difference between the test and control group for p> 0.05 (p = 1.00). For χ2=8,17 (p=0,06, p<0,05) there is an association between Prevotella intermedia, and composite genotype. Between positive genotype and analyzed bacterial species A. actinomycetem comitans for p> 0.05 (p = 1.00), P. gingivalis for p> 0.05 (p = 0.16), T. Forsythia for p> 0.05 (p = 0.20), T. Denticola for p> 0.05 (p = 0.64) no association was found.

CONCLUSION

This investigations confirmed the strong association of these five examined periopathogenes with periodontitis.

Immunomodulatory factors gene polymorphisms in chronic periodontitis: an overview

BACKGROUND

Chronic periodontitis (CP), defines as destruction of the supporting tissues of the teeth and resorption of the alveolar bone. It is widespread in human populations and represent an important problem for public health. CP results from inflammatory mechanisms created by the interaction between environmental and host genetic factors that confer the individual susceptibility to the disease.

AIM

The aim of the current study was to explore and summarize some functional biomarkers that are associated with CP susceptibility.

METHODS

CP is considered to be a multifactorial disease. The pathogenesis of multifactorial diseases is characterized by various biological pathways. The studies revealed that polymorphisms were associated with susceptibility to periodontal diseases. In other word, genetic variations can change the development of CP. However, there are some conflicting results, because there are different variations in frequency of some alleles in any populations. Therefore, we conducted the current review to completely understanding the special biomarkers for CP.

RESULTS

There is some evidence that SNPs in the IL-1α, IL-1β, IL1RN, IL-6, IL-10, TNF-α, TGF-β1, IFN-γ and VDR may be associated with CP susceptibility.

CONCLUSION

In conclusion, numerous studies have reported the host genetic factors associated with CP susceptibility and related traits. Therefore, it is prevail to study the multiple SNPs and their effects to find the useful diagnosis methods. The current study will investigate the relationship between polymorphisms in cytokine genes and the susceptibility to the chronic periodontitis.

Environmental lead effects on gene expression in oral epithelial cells

BACKGROUND AND OBJECTIVE

Host responses in periodontitis span a range of local and emigrating cell types and biomolecules. Accumulating evidence regarding the expression of this disease across the population suggests some component of genetic variation that controls onset and severity of disease, in concert with the qualitative and quantitative parameters of the oral microbiome at sites of disease. However, there remains little information regarding the capacity of accruing environmental stressors or modifiers over a lifespan at both the host genetic and microbial ecology levels to understand fully the population variation in disease. This study evaluated the impact of environmental lead exposure on the responses of oral epithelial cells to challenge with a model pathogenic oral biofilm.

METHODS AND RESULTS

Using NanoString technology to quantify gene expression profiles of an array of 511 host response-associated genes in the epithelial cells, we identified an interesting primary panel of basal responses of the cells with numerous genes not previously considered as major response markers for epithelial cells, eg, interleukin (IL)-32, CTNNB1, CD59, MIF, CD44 and CD99. Even high levels of environment lead had little effect on these constitutive responses. Challenge of the cells with the biofilms (Streptococcus gordonii/Fusobacterium nucleatum/Porphyromonas gingivalis) resulted in significant increases in an array of host immune-related genes (134 of 511). The greatest magnitude in differential expression was observed with many genes not previously described as major response genes in epithelial cells, including IL-32, CD44, NFKBIA, CTSC, TNFAIP3, IL-1A, IL-1B, IL-8 and CCL20. The effects of environmental lead on responses to the biofilms were mixed, although levels of IL-8, CCL20 and CD70 were significantly decreased at lead concentrations of 1 and/or 5 μmol/L.

CONCLUSION

The results provided new information on a portfolio of genes expressed by oral epithelial cells, targeted substantial increases in an array of immune-related genes post-biofilm challenge, and a focused impact of environmental lead on these induced responses.

Relationship between -889 C/T polymorphism in interleukin-1A gene and risk of chronic periodontitis: Evidence from a meta-analysis with new published findings

Background

Periodontitis results from an inflammatory response caused by accumulative microorganisms in periodontal sites. Several factors are involved in pathogenesis of periodontitis, for example the -889 C/T polymorphism in interleukin-1A gene. This study aimed to evaluate the relationship between this polymorphism and risk of development of chronic periodontitis by a meta-analysis based in new published findings.

Material and Methods

Thereunto a review in literature was performed in the electronic biomedical and education databases (Cochrane Library, Google Scholar, MEDLINE and PubMed) to studies published before August 2, 2015, the abstracts were evaluated and the data extraction performed by two calibrated examiners. The calculations of the meta-analysis were obtained through statistical software Review Manager version 5.2 with calculation of Odds Ratio (OR), heterogeneity (I²) and Funnel plots with P <0.05.

Results

In overall, twenty-one case/control studies were selected with 2,174 patients with chronic periodontitis and 1, 756 controls. The meta-analysis showed T allele was associated with chronic periodontitis (OR = 1.22, 95% CI: 1.09, 1.36, P = 0.0004) with decreased value to heterogeneity (I² = 15%, P = 0.28). TT genotype was associated to patients with chronic periodontitis (OR = 1.40, 95% CI: 1.07, 1.83, P = 0.01). No publication bias was found in this meta-analysis by asymmetry in Funnel plots.

Conclusions

This meta-analysis with 2,174 patients with chronic periodontitis and 1, 756 controls evidenced the -889 C/T polymorphism is associated to risk of development of chronic periodontitis with no significant value to heterogeneity to allelic evaluation.

Key words:Alleles, odds ratio, periodontal disease, cytokines.

Interactive effects of periodontitis and orthodontic tooth movement on dental root resorption, tooth movement velocity and alveolar bone loss in a rat model

BACKGROUND

Many adult orthodontic patients suffer from chronic periodontitis with recurrent episodes of active periodontal inflammation. As their number is steadily increasing, orthodontists are more and more frequently challenged by respective treatment considerations. However, little is currently known regarding interactive effects on undesired dental root resorption (DRR), tooth movement velocity, periodontal bone loss and the underlying cellular and tissue reactions.

MATERIAL AND METHODS

A total of 63 male Fischer344 rats were used in three consecutive experiments employing 21 animals each (A/B/C), randomly assigned to 3 experimental groups (n=7, 1/2/3), respectively: (A) CBCT; (B) histology/serology; (C) RT-qPCR-(1) control; (2) orthodontic tooth movement (OTM) of the first/second upper left molars (NiTi coil spring, 0.25N); (3) OTM with experimentally induced periodontitis (cervical silk ligature). After 14days of OTM, we quantified blood leukocyte level, DRR, osteoclast activity and relative gene expression of inflammatory and osteoclast marker genes within the dental-periodontal tissue as well as tooth movement velocity and periodontal bone loss after 14 and 28 days.

RESULTS

The experimentally induced periodontal bone loss was significantly increased by concurrent orthodontic force application. Periodontal inflammation during OTM on the other hand significantly augmented the extent of DRR, relative expression of inflammatory/osteoclast marker genes, blood leukocyte level and periodontal osteoclast activity. In addition, contrary to previous studies, we observed a significant increase in tooth movement velocity.

CONCLUSIONS

Although accelerated tooth movement would be favourable for orthodontic treatment, our results suggest that orthodontic interventions should only be performed after successful systematic periodontal therapy and paused in case of recurrent active inflammation.

Polymorphic Regions in Fc Gamma Receptor and Tumor Necrosis Factor-α Genes and Susceptibility to Chronic Periodontitis in a Cohort From South India

BACKGROUND

Polymorphisms in the immunoglobulin G Fc receptor II (FcGR) and tumor necrosis factor-α (TNFA) genes are known to influence pathogenesis and severity of several inflammatory conditions. Association of FcGR and TNFA gene polymorphisms with chronic periodontitis (CP) susceptibility has been found to be diverse among different ethnic populations. Objectives of the present study are to determine association of functional single nucleotide polymorphisms (SNPs) in FcGR and TNF-α genes with CP susceptibility in a cohort from South India.

METHODS

Polymorphisms of: 1) FCGR2A 131His/Arg (rs1801274); 2) FCGR2B 232Ile/Thr (rs1050501); 3) TNFA -1031T/C (rs1799964); and 4) TNFA -863C/A (rs1800630) were analyzed among patients with healthy gingiva (n = 176) and patients with CP (n = 177). Genotyping was performed using allele-specific real-time polymerase chain reaction assay. Association between CP and SNPs was examined by multivariable logistic regression analysis with adjustment for: 1) age; 2) sex; and 3) oral hygiene index (OHI). Epistatic interaction between FcGR polymorphisms and interleukin 1B (IL1B) +3954C/T (rs1143634) was assessed using multifactorial dimensionality reduction analysis.

RESULTS

Among four SNPs analyzed, only FCGR2A 131His/Arg showed significant association with CP in a dominant model (odds ratio: 1.6; 95% confidence interval: 1.028 to 2.530). This significance disappeared after correcting for multiple comparisons using Bonferroni analysis, or after adjusting for age, sex, and OHI. A significant redundant interaction between IL1B +3954 C/T and FCGR2A 131His/Arg was observed.

CONCLUSION

Study results suggest the variant form of the SNP in FCGR2A 131His/Arg, FCGR2B 232Ile/Thr, TNFA -1031T/C, and TNFA -863C/A are not associated with CP susceptibility in the selected cohort from South India.