Interleukin-1β (3953/4) C→T polymorphism increases the risk of chronic periodontitis in Asians: evidence from a meta-analysis of 20 case-control studies

The Impact of IL1B rs1143634 and DEFB1 rs11362 Variants on Periodontitis Risk in Phenylketonuria and Type 1 Diabetes Mellitus Patients in a Latvian Population

OBJECTIVES

Periodontitis is a multifactorial disease that affects approximately 11% of the global population. The objective of this study was to examine whether, among individuals with phenylketonuria and type 1 diabetes mellitus, those with the IL1B rs1143634 and/or DEFB1 rs11362 genetic variants exhibit a higher periodontitis risk compared to healthy controls.

MATERIALS AND METHODS

In all, 43 phenylketonuria patients (aged 12-53), 28 type 1 diabetes mellitus patients (aged 11-40), and 63 healthy controls (aged 12-53) were included. The evaluation of periodontitis risk was conducted using the Silness-Löe plaque index, the Greene-Vermillion index, and an assessment for the necessity of calculus removal. Genetic variants rs1143634 and rs11362 were genotyped from salivary samples using restriction length polymorphism analysis.

RESULTS

The DEFB1 rs11362 variant was associated with higher Silness-Löe and Greene-Vermillion index scores in phenylketonuria patients (p = 0.011 and p = 0.043, respectively). The IL1B rs1143634 variant was associated with lower calculus removal necessity in type 1 diabetes mellitus patients (p = 0.030). Clinical examination showed the worst oral hygiene index scores for PKU patients. PKU patients also reported the least consistent tooth brushing and flossing habits.

CONCLUSIONS

Genetic associations between DEFB1 rs11362 and IL1B rs1143634 variants and oral hygiene indices were observed in the PKU and T1DM groups, suggesting that genetic factors may contribute to periodontal health differences in these populations. Further research with a larger sample size is needed to confirm these findings and develop targeted oral health interventions.

Epigenetics in susceptibility, progression, and diagnosis of periodontitis

Periodontitis is characterized by irreversible destruction of periodontal tissue. At present, the accepted etiology of periodontitis is based on a three-factor theory including pathogenic bacteria, host factors, and acquired factors. Periodontitis development usually takes a decade or longer and is therefore called chronic periodontitis (CP). To search for genetic factors associated with CP, several genome-wide association study (GWAS) analyses were conducted; however, polymorphisms associated with CP have not been identified. Epigenetics, on the other hand, involves acquired transcriptional regulatory mechanisms due to reversibly altered chromatin accessibility. Epigenetic status is a condition specific to each tissue and cell, mostly determined by the responses of host cells to stimulations by local factors, like bacterial inflammation, and systemic factors such as nutrition status, metabolic diseases, and health conditions. Significantly, epigenetic status has been linked with the onset and progression of several acquired diseases. Thus, epigenetic factors in periodontal tissues are attractive targets for periodontitis diagnosis and treatments. In this review, we introduce accumulating evidence to reveal the epigenetic background effects related to periodontitis caused by genetic factors, systemic diseases, and local environmental factors, such as smoking, and clarify the underlying mechanisms by which epigenetic alteration influences the susceptibility of periodontitis.

Association between Interleukin-1β Gene Polymorphism and Chronic Periodontitis

Objectives Periodontitis is a pathological condition of the oral cavity, originating from multiple factors, including microbial, environmental and genetic factors. The vulnerability to several pathologies has been studied with the relationship to genetic polymorphisms, and one of the most prominent is the single nucleotide polymorphisms throughout the genome. The study aimed to find out the association of single nucleotide polymorphism (SNP) of interleukin-1β +3954 gene with chronic periodontitis (CP) in Pakistan

Materials and Methods This case–control study was conducted at Dow University of Health Sciences. DNA was extracted from the blood and amplified by using conventional polymerase chain reaction of respective genes followed by sequencing. Mann–Whitney test accessed the difference of clinical parameters between cases and controls, and Fisher’s exact test was applied to access the association of alleles between subjects. Data entered and analyzed using SPSS 21.

Results Significant differences were observed in clinical parameters in cases and controls ( p < 0.001). In the IL-1β +3954 gene, T alleles were significantly higher in cases as compared with controls ( p < 0.001). Genotype CC was significantly dominant in the controls and genotype CT and TT in patients (Chi-square = 19.83, p < 0.001).

Conclusion Within the study’s limits, IL-1β +3954 gene polymorphism is associated with periodontitis and is expected to be among the several causes of respective pathology in Pakistan’s population.

Expression of miR-155 and miR-146a in the saliva of patients with periodontitis and its clinical value

OBJECTIVE

To explore the significance of microRNA-155 (miR-155) and microRNA-46a (miR-46a) in the diagnosis of periodontitis (PD).

METHODS

A total of 41 patients with PD admitted to our hospital between September 2017 and August 2019 were enrolled into an observation group (obs group), and 35 healthy individuals during the same period were enrolled into a control group (con group). A qRT-PCR assay was carried out to quantify miR-155 and miR-146a expression, and the relationship between the expression of miR-155 and miR-146a and severity and clinical indicators of PD was analyzed.

RESULTS

The obs group showed significantly higher expression of saliva miR-155 and miR-146a than the con group (P<0.05), and the expression of them was positively correlated with the severity of their PD. It was also positively correlated with gingival index (GI), attachment loss (AL), plaque index (PLI), probing depth (PD), and bleeding on probing (BOP) of them. Additionally, according to the receiver operating characteristic (ROC) curves, the area under the curve (AUC), specificity, and sensitivity of miR-155 in diagnosing PD were 0.887, 78%, and 97.14%, respectively, and those of miR-146a in diagnosing PD were 0.745, 58.54%, and 88.57%, respectively.

CONCLUSION

MiR-155 and miR-146a were both highly expressed in the saliva of patients with PD, and the expression of them was positively correlated with the severity and clinical indexes of PD, so miR-155 and miR-146a might be involved in the development and progression of PD.

Association between TNF-α G-308A (rs1800629) polymorphism and susceptibility to chronic periodontitis and type 2 diabetes mellitus: A meta-analysis

BACKGROUND AND OBJECTIVE

Although the association between tumor necrosis factor-α (TNF-α) G-308A (rs1800629) polymorphism and chronic periodontitis (CP), chronic periodontitis with type 2 diabetes mellitus (DP) is assumed, results of this association have been contradictory. The aim of this study was to assess the relationship between rs1800629 polymorphism and CP/DP susceptibility.

METHODS

We searched for studies on PubMed, Web of Science, MEDLINE, Chinese National Infrastructure, and WanFang databases. Study selection was performed using specific inclusion and exclusion criteria and fulfilled the PECO (participant, exposure, comparison, and outcome) format. The relationship between rs1800629 polymorphism and CP/DP susceptibility was evaluated by the effect summary odds ratio (OR) and 95% confidence intervals (CIs). Allele, dominant, and recessive genetic models were computed to assess the strength of the association.

RESULTS

A total of 25 case-control studies were included in the analysis. In the Asian population, TNF-α rs1800629 polymorphism was found to be significantly associated with CP in the overall analyses and for all genetic contrasts, while no significant risks were found among Caucasian populations for all genetic contrasts. The TNF-α rs1800629 polymorphism was also associated with increased DP risk in Asians under the fixed-effects model, but not in the recessive comparison.

CONCLUSION

The meta-analysis suggested that TNF-α rs1800629 polymorphism might affect the risk of CP and DP, particularly in individuals of Asian descent.

Non-pharmacological Strategies Against Systemic Inflammation: Molecular Basis and Clinical Evidence

Systemic inflammation is a common denominator to a variety of cardiovascular (CV) and non-CV diseases and relative risk factors, including hypertension and its control, metabolic diseases, rheumatic disorders, and those affecting the gastrointestinal tract. Besides medications, a non-pharmacological approach encompassing lifestyle changes and other complementary measures is mentioned in several updated guidelines on the management of these conditions. We performed an updated narrative review on the mechanisms behind the systemic impact of inflammation and the role of non-pharmacological, complementary measures centered on lowering systemic phlogosis for preserving or restoring a good global health. The central role of genetics in shaping the immune response is discussed in conjunction with that of the microbiome, highlighting the interdependence and mutual influences between the human genome and microbial integrity, diversity, and functions. Several plausible strategies to modulate inflammation and restore balanced crosstalk between the human genome and the microbiome are then recapitulated, including dietary measures, active lifestyle, and other potential approaches to manipulate the resident microbial community. To date, evidence from high-quality human studies is sparse to allow the unconditioned inclusion of understudied, though plausible solutions against inflammation into public health strategies for global wellness. This gap claims further focused, well-designed research targeted at unravelling the mechanisms behind future personalized medicine.

Periodontal health and disease: The contribution of genetics

Periodontitis is an infectious, inflammatory disease that is associated with a complex interplay between specific bacteria, host response, and environmental factors. Because of its high degree of familial aggregation, specifically for the more aggressive forms of the disease, genetics factors have been implicated in disease pathogenesis for several decades. This review provides an overview of what we currently know regarding the genetic and epigenetic contributions to periodontal disease and discusses future opportunities in the field.

Diagnostic Accuracy of Oral Fluids Biomarker Profile to Determine the Current and Future Status of Periodontal and Peri-Implant Diseases

Severe periodontitis is ranked as the sixth most prevalent disease affecting humankind, with an estimated 740 million people affected worldwide. The diagnosis of periodontal diseases mainly relies upon assessment of conventional clinical parameters. However, these parameters reflect past, rather than current, clinical status or future disease progression and, likely, outcome of periodontal treatment. Specific and sensitive biomarkers for periodontal diseases have been examined widely to address these issues and some biomarkers have been translated as point-of-care (PoC) tests. The aim of this review was to provide an update on PoC tests for use in the diagnosis and management of periodontal diseases. Among the PoC tests developed so far, active matrix metalloproteinase-8 has shown promising results in terms of diagnostic and prognostic values. However, further studies are required to increase the sensitivity and specificity via combining more than one biomarker and merging these test kits with periodontal risk assessment tools. Furthermore, the validity of these test kits needs to be investigated by applying the results in further independent studies and the impact on these test kits', together with the results of risk factors for periodontal diseases, such as diabetes and smoking, also needs to be examined.

Detection of association between periodontitis and polymorphisms of IL-1β + 3954 and TNF-α -863 in the Korean population after controlling for confounding risk factors

Background and Objective

Interleukin (IL)‐1 and tumor necrosis factor (TNF)‐α are inflammatory cytokines that play an important role in periodontitis, and their genetic variations have been suggested to be associated with increased risk of periodontitis. Focusing on three single nucleotide polymorphisms (SNPs) of IL‐1α + 4845, IL‐1β + 3954, and TNF‐α −863, we aimed to investigate the relationship between periodontitis risk and the polymorphisms of IL‐1 α/β and TNF‐α in Koreans.

Material and Methods

Mouthwash samples from 548 subjects (135 controls without periodontitis, 387 generalized chronic periodontitis patients, and 26 generalized aggressive periodontitis patients) were collected for isolation of genomic DNA. Genotyping of selected SNPs was performed using real‐time PCR. Univariable associations between the polymorphisms and periodontitis were assessed by chi‐squared test or Fisher's exact test. To evaluate the association after controlling for confounding effects of various risk factors, we stratified the subjects according to the presence or absence of self‐reported diseases and employed multiple logistic regression model to adjust for age, smoking status, and oral hygiene indices and behaviors.

Results

Significant association of IL‐1β + 3954 and TNF‐α −863 polymorphisms with periodontitis was observed after adjusting for the confounding risk factors, but not in univariable association analysis. The significant association between genotype CT of IL‐1β + 3954 and increased risk of advanced periodontitis was consistently detected regardless of the status of self‐reported diseases. In the polymorphism of TNF‐α −863, the genotype with minor allele (CA + AA) was significantly associated with periodontitis susceptibility, which was observed only in the subjects with self‐reported diseases.

Conclusion

The results suggest that genetic variations of IL‐1β + 3954 and TNF‐α −863 are associated with increased risk of periodontitis in Koreans. In addition, our findings underscore the importance of controlling for confounding risk factors to detect significant association between genetic factors and risk of periodontitis. A further well‐designed large‐scale study is needed to warrant our results.

Analysis of the association between the XRCC2 rs3218536 polymorphism and ovarian cancer risk

INTRODUCTION

Results conflict on the association between the XRCC2 rs3218536 polymorphism and ovarian cancer risk, despite wide-ranging investigations. This meta-analysis examines whether the XRCC2 rs3218536 polymorphism is associated with ovarian cancer risk.

MATERIAL AND METHODS

Eligible case-control studies were searched in PubMed. We therefore performed a meta-analysis of 5,802 ovarian cancer cases and 9,390 controls from 7 articles published. The strength of association between XRCC2 rs3218536 polymorphism and ovarian cancer susceptibility was calculated using pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs).

RESULTS

No statistically significant associations between XRCC2 rs3218536 polymorphism and ovarian cancer risk were found in any genetic models. However, a significant relationship with ovarian cancer risk was discovered when the high quality studies were pooled in the meta-analysis (AA vs. GG: OR = 0.59, 95% CI: 0.37-0.94, p = 0.03; GA vs. GG: OR = 0.87, 95% CI: 0.78-0.96, p = 0.009; GA + AA vs. GG: OR = 0.85, 95% CI: 0.77-0.94, p = 0.003; AA vs. GG + GA: OR = 0.60, 95% CI: 0.38-0.95, p = 0.03).

CONCLUSIONS

This meta-analysis shows that the XRCC2 rs3218536 polymorphism was associated with ovarian cancer risk overall for high quality studies. Non-Caucasian groups and high quality studies should be further studied.

Quality of methods and reporting in association studies of chronic periodontitis and IL1A -889 and IL1B +3953/4 SNPs: A systematic review

OBJECTIVE

The aim of this systematic review was to evaluate the quality of reporting and methodology in genetic association studies between IL1A -889 and IL1B +3954 polymorphisms and chronic periodontitis.

BACKGROUND

Evidence provided by periodontal research on genetic risk factors is of uttermost importance in clinical practice as a possible diagnostic and prognostic tool for periodontitis. Inadequate reporting of results as well as high risk of bias due to methodological inconsistency hampers the integration of evidence in terms of clinical applicability.

METHODS

This review includes case-control studies in humans published between 1997 and July 2017. Searching was conducted through MEDLINE, EMBASE, and search handing. Specific scoring systems have been developed to evaluate the quality of methods and reporting. Each article was scored according to its adequacy, and then, the total number and the percentage of items positively qualified for both methods and reporting were calculated. The quality of methods in studies scoring 0-6, 7-12, and 13-16 was, respectively, considered poor, moderate, and good. For reporting, scores of 0-9, 10-18, and 19-26 were deemed of poor, moderate, and good quality, respectively. Pearson's correlation coefficient was calculated to explore the correlation between the year of publication and the quality in terms of methods and reporting.

RESULTS

From the 531 screened studies, 52 met the inclusion criteria and were thus included in the study. The quality of methods and reporting of published genetic association papers on IL1 and chronic periodontitis is moderate. On a scale from 0 to 16, the mean score for methods of the reviewed studies was 8.19 ± 1.93. The items more frequently considered inadequate concerned the handling of confounders in statistical analysis, especially oral hygiene habits, socioeconomic status, subgingival colonization of specific periodontal pathogens, and stress. A significant positive correlation was found between the year of publication and the quality scores in terms of method (r = 0.401, P = 0.003). In terms of reporting, the mean score was 14.83 ± 3.04 on a scale from 0 to 26 and it was considered overall moderate. No statistically significant correlation was found between the year of publication and the quality of reporting (P = 0.266).

CONCLUSIONS

The association between IL1A -889 and IL1B +3954 polymorphisms and chronic periodontitis is questionable due to methodological inconsistency. Evidence arising from meta-analysis is unreliable due to high risk of bias and moderate quality in terms of reporting.

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.

Host genetics role in the pathogenesis of periodontal disease and caries

BACKGROUND

This study aimed to produce the latest summary of the evidence for association of host genetic variants contributing to both periodontal diseases and caries.

MATERIALS AND METHODS

Two systematic searches of the literature were conducted in Ovid Medline, Embase, LILACS and Cochrane Library for large candidate gene studies (CGS), systematic reviews and genome-wide association studies reporting data on host genetic variants and presence of periodontal disease and caries.

RESULTS

A total of 124 studies were included in the review (59 for the periodontitis outcome and 65 for the caries outcome), from an initial search of 15,487 titles. Gene variants associated with periodontitis were categorized based on strength of evidence and then compared with gene variants associated with caries. Several gene variants showed moderate to strong evidence of association with periodontitis, although none of them had also been associated with the caries trait.

CONCLUSIONS

Despite some potential aetiopathogenic similarities between periodontitis and caries, no genetic variants to date have clearly been associated with both diseases. Further studies or comparisons across studies with large sample size and clear phenotype definition could shed light into possible shared genetic risk factors for caries and periodontitis.

Pretreatment with obestatin inhibits the development of acetic acid-induced colitis in rats

INTRODUCTION

Obestatin is a 23-amino acid peptide derived from proghrelin, a common prohormone for ghrelin and obestatin. Previous studies have shown that obestatin exhibits some protective and therapeutic effects in the pancreas and stomach. The aim of this study was to examine the effect of pretreatment with obestatin on the development of acetic acid-induced colitis.

MATERIAL AND METHODS

Studies were performed on Wistar rats. Before induction of colitis, rats were treated intraperitoneally with saline or obestatin, administered twice at a dose of 4, 8 or 16 nmol/kg/dose. The first dose of saline or obestatin was administered 8 h before the induction of colitis, the second one 7 h after the first dose. Colitis was induced by enema with 1 ml of 4% acetic acid solution. The severity of colitis was assessed 1 or 24 h after administration of enema.

RESULTS

Pretreatment with obestatin administered at a dose of 8 or 16 nmol/kg/dose significantly reduced the area of mucosal damage evoked by enema with acetic acid (p < 0.05). This effect was accompanied by an improvement of mucosal blood flow and DNA synthesis in the colon. Moreover, obestatin administered at a dose of 8 or 16 nmol/kg/dose significantly reduced mucosal concentration of IL-1β and activity of myeloperoxidase (p < 0.05).

CONCLUSIONS

Pretreatment with obestatin exhibited a protective effect in the colon, leading to a reduction of colonic damage in acetic acid-induced colitis. This effect was associated with an improvement of mucosal blood flow, an increase in mucosal cell proliferation, and a decrease in local inflammation.

Genetic Factors and the Risk of Periodontitis Development: Findings from a Systematic Review Composed of 13 Studies of Meta-Analysis with 71,531 Participants

Purpose. This work aimed to synthesize the results of recent meta-analysis focusing on polymorphism in inflammatory mediators and its relation with the risk of periodontitis development. Materials and Methods. A systematic search was conducted using databases for publications prior to October 2016. Three examiners extracted data from articles with a clear association between polymorphisms in the inflammatory mediator gene and the development of periodontitis through meta-analysis using the fixed or randomized statistical models to calculate the Odds Ratio with values of P < 0.05 considered significant. Results. A total of 13 meta-analysis articles with 25 polymorphisms in seven interleukins (IL-1A, IL-1B, IL-4, IL-6, IL-8, IL-10, and IL-18), three cellular receptors (Fcγ receptors: FCGR2A, FCGR3A, and FCGR3B), and five inflammatory mediators (COX-2, MMP-2, MMP-3, MMP-8, and MMP-9), with a total of 71,531 participants, approaching different classifications of the disease. Conclusion. The study demonstrated that polymorphisms in the IL-1A, IL-1B, IL-6, IL-10, MMP-3 (chronic form), and MMP-9 (chronic form) polymorphisms were significantly associated with the risk of developing periodontitis, whereas other polymorphisms in the IL-4, IL-8, IL-18, Fcγ, COX-2, MMP-2, MMP-3 (aggressive), MMP-8, and MMP-9 (aggressive) polymorphisms had no significant association with risk of developing periodontitis.

Regulatory elements and genetic variations in periodontal diseases

OBJECTIVE

Current evidence suggests that many GWAS and IL1 SNPs are associated with periodontal diseases but their functional role remains ambiguous. Therefore, it is imperative to elucidate the molecular pathways through which these SNPs might act on the development of the disease. The purpose of this review was to highlight the regulatory elements of noncoding regions of the genome and provide insights on the functional role of periodontitis-associated GWAS and IL1 SNPs.

DESIGN

A search was performed using ENCODE data available on different browsers.

RESULTS

GWAS and IL1 SNPs overlap DNase I hypersensitivity sites, histone modifications and transcription binding sites. Some of these noncoding variants influenced the transcription activity of inflammatory genes.

CONCLUSION

SNPs associated with periodontal diseases may contribute to the development of the disorder through their functional roles. Unraveling the character of genetic components might explain the diversity of clinical phenotypes among population groups as well as disease susceptibility.

Inflammatory Cytokines Interleukin-1β and Tumour Necrosis Factor-α - Novel Biomarkers for the Detection of Periodontal Diseases: a Literature Review

Objectives

The article aims to discuss the IL-1β and TNF-α potential use as salivary biomarkers of periodontal diseases pathogenesis and progression.

Material and Methods

This literature review has been registered in PROSPERO database with following number: CRD42016035729. Data investigation was performed on PubMed database as the main source of studies. The following search terms were used: “salivary biomarkers”, “periodontal diseases”, “TNF-alpha”, “Interleukin-1 beta”. Clinical trials and animal experimental models of periodontal disease were included in the discussion. In regards to inclusive dates, published studies from January 2006 to December 2015 were considered in this review along with the mentioned inclusion criteria.

Results

IL-1β and TNF-α salivary levels increased in diseased groups, they were associated with onset and disease severity, and their levels reduced in response to periodontal therapy. IL-1β and TNF-α could be promising biomarkers in the detection of periodontal diseases.

Conclusions

The use of a salivary cytokine-based diagnosis appears to be a screening method capable of diagnosing periodontal diseases in an early fashion, establishing an era of individualized clinical decisions.