Interleukin-1 Gene Variability and Plasma Levels in Czech Patients with Chronic Periodontitis and Diabetes Mellitus

Genetic polymorphism of interleukin-1 receptor antagonist in Type 1 diabetic children

BACKGROUND

Interleukin-1 receptor antagonist (IL1RN) variable number tandem repeats (VNTRs) are not fully understood in Type 1 diabetes mellitus (T1DM). It may affect IL1RN level and modify the disease risk. We aimed to study IL1RN VNTR polymorphism in Egyptian children with T1DM to clarify its potential role as a risk factor for T1DM and its effect on plasma IL1RN level.

METHODS

A case-controlled study including 200 children (120 T1DM and 80 controls) was carried on. All children were subjected to genotyping of IL1RN VNTR. Plasma IL1RN was estimated by ELISA.

RESULTS

The A1A2 and LS genotypes and A2 allele were significantly higher among cases compared to controls with increased T1DM risk (OR = 5.35, 2.56 and 3.13, respectively). The S allele was significantly elevated in cases compared to controls with 2.09-fold increased risk of having T1DM. The median plasma IL1RN significantly decreased in cases compared to controls. Within cases, IL1RN was significantly decreased in LS versus LL genotype.

CONCLUSIONS

There is a strong relationship between IL1RN VNTR and T1DM in Egyptian children. A1A1 genotype, LL genotype, A1 allele, and L allele were protective. A1A2 and LS genotypes, short (S), and A2 alleles were risk factors. IL1RN was decreased in T1DM, especially in LS genotype.

IMPACT

The relationship between IL1RN gene polymorphism and risk for T1DM among Egyptian children. Plasma IL1RN protein level in T1DM. Low IL1RN protein level in T1DM patients could be therapeutic targets for IL1RN medications in the future.

Association between IL-1B (-511)/IL-1RN (VNTR) polymorphisms and type 2 diabetes: a systematic review and meta-analysis

Interleukin-1 (IL-1) plays an essential role in the immune pro-inflammatory process, which is regarded as one of many factors in the development of type 2 diabetes mellitus (T2DM). Several case-control studies have illustrated the association of the IL-1B (-511) (rs16944, Chr 2:112,837,290, C/T Intragenic, Transition Substitution) and IL-1RN (VNTR) (gene for IL-1 receptor antagonist, IL-1RA, 86 bp tandem repeats in intron 2) polymorphisms with T2DM risk. However, the results were inconsistent and inconclusive. We performed a meta-analysis (registry number: CRD42021268494) to assess the association of the IL-1B (-511) and IL-1RN (VNTR) polymorphisms with T2DM risk. Random-effects models were applied to calculate the pooled ORs (odds ratios) and 95% CIs (confidence intervals) to test the strength of the association in the overall group and subgroups stratified by ethnicity, respectively. Between-study heterogeneity and publication bias were evaluated by the Q-test, I² statistic, Harbord test, and Peters test accordingly. Sensitivity analyses were also performed. A total of 12 publications evaluating the association of IL-1B (-511) and IL-1RN (VNTR) polymorphisms with the risk of T2DM development were included. The meta-analysis showed that IL-1RN (VNTR) was related to the increasing development of T2DM risk in the recessive model (OR = 1.62, 95% CI [1.09-2.42], P_het = 0.377, P_z = 0.018) and in the homozygous model (OR = 2.02, 95% CI [1.07-3.83], P_het = 0.085, P_z = 0.031), and the IL-1RN 2* allele was found a significant association with evaluated T2DM risk in all ethnicities (OR = 2.08, 95% CI [1.43-3.02], P_het < 0.001, P_z < 0.001) and in EA (OR = 2.01, 95% CI [1.53-2.66], P_het = 0.541, P_z < 0.001). Moreover, stratification by ethnicity revealed that IL-1B (-511) was associated with a decreased risk of T2DM in the dominant model (OR=0.76, 95% CI [0.59-0.97], P_het = 0.218, P _z = 0.027) and codominant model (OR = 0.73, 95% CI [0.54-0.99], P_het = 0.141, P_z = 0.040) in the East Asian (EA) subgroup. Our results suggest that the IL-1RN 2* allele and 2*2* homozygous polymorphism are strongly associated with increasing T2DM risk and that the IL-1B (-511) T allele polymorphism is associated with decreasing T2DM risk in the EA subgroup.

Association between Periodontitis and Genetic Polymorphisms in Interleukins among Patients with Diabetes Mellitus

There is a perplexity in the association between interleukin (IL) polymorphisms and periodontitis among patients with and without diabetes mellitus (DM). The aim of the present study was to evaluate indexed data regarding the association between periodontitis and genetic polymorphisms in interleukins among patients with and without DM. The addressed question was “Is there an association between periodontitis and polymorphisms in interleukins among patients with and without DM?” Original studies were included. Indexed databases were searched, and the pattern of the present literature review was customized to summaries’ the pertinent information. Eight studies were included and processed for data extraction. Two studies showed that polymorphisms in IL-1B genes aggravate periodontitis in patients with type-2 DM, and two studies showed that IL-1B genes either do not or are less likely to contribute towards the progression of periodontitis in patients with type-2 DM. Two studies reported that IL genes do not show cross-susceptibility with periodontitis and type-2 DM. One study reported that the primary factor that governs the occurrence and progression of periodontitis in patients with and without type-2 DM is poor routine oral hygiene maintenance. Seven studies had a high risk of bias. The role of IL gene polymorphisms in the development and progression of periodontitis in patients with and without DM remains controversial.

Long-term inhibition of dipeptidyl-peptidase 4 reduces islet infiltration and downregulates IL-1β and IL-12 in NOD mice

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DPP-4 inhibition reduced CD4+T cells infiltration and ameliorated insulitis.

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DPP-4 inhibition downregulated serum IL-1β and IL-12.

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LPS increased CD11b+ cells to infiltrate into islets.

Dipeptidyl-peptidase 4 (DPP-4) inhibitor (sitagliptin) is a novel anti-hyperglycemia drug in the treatment of type 2 diabetes. However, its potential in type 1 diabetes is still unclear. Recent studies show that increased infection, especially respiratory tract infection, is significantly associated with DPP-4 inhibitors. In this study, we aimed to explore the effects of long-term inhibition of DPP- 4 on innate immunity in type 1 diabetes. Forty mice were randomly divided into 4 groups (n = 10 in each group): control group, lipopolysaccharide (LPS) group, sitagliptin group and sitagliptin + LPS group. The concentrations of IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, TNF-α and IFN-γ were measured with Mesco Scale Discovery multiplexed-assay kit. Immunohistochemistry staining of pancreases was performed and insulitis scores for each islet were determined. The results showed that DPP-4 inhibition has no effect on incident rate of diabetes and metabolic parameters in NOD mice. Long-term inhibition of DPP-4 reduced CD4+T cells to infiltrate into islets and ameliorated insulitis in NOD mice. DPP-4 inhibition downregulated serum interleukin IL-1β and IL-12 in NOD mice. However, it had no significant effect on LPS-induced IL-1β, IL-6, IL-10, IL-12, tumor necrosis factor (TNF)-α and interferon (IFN)-γ in NOD mice. In conclusion, Long-term inhibition of DPP-4 exists anti-inflammatory effect in type 1 diabetes probably by reducing CD4+T cells to infiltrate into islets and downregulating L-1β and IL-12 in serum.

Inflammatory Networks Linking Oral Microbiome with Systemic Health and Disease

The dance between microbes and the immune system takes place in all biological systems, including the human body, but this interaction is especially complex in the primary gateway to the body: the oral cavity. Recent advances in technology have enabled deep sequencing and analysis of members and signals of these communities. In a healthy state, the oral microbiome is composed of commensals, and their genes and phenotypes may be selected by the immune system to survive in symbiosis. These highly regulated signals are modulated by a network of microbial and host metabolites. However, in a diseased state, host-microbial networks lead to dysbiosis and considerable burden to the host prior to systemic impact that extends beyond the oral compartment. Interestingly, we presented data demonstrating similarities between human and mice immune dysbiosis and discussed how this affects the host response to similar pathobionts. The host and microbial signatures of a number of disease states are currently being examined to identify potential correlations. How the oral microbiome interacts with inflammation and the immune system to cause disease remains an area of active research. In this review, we summarize recent advancements in understanding the role of oral microbiota in mediating inflammation and altering systemic health and disease. In line with these findings, it is possible that existing conditions may be resolved by targeting specific immune-microbial markers in a positive way.

Genetic polymorphisms in the Interleukins IL1B, IL4, and IL6 are associated with concomitant periodontitis and type 2 diabetes mellitus in Brazilian patients

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.

Interleukin Gene Variability and Periodontal Bacteria in Patients with Generalized Aggressive Form of Periodontitis

Host genetic predispositions to dysregulated immune response can influence the development of the aggressive form of periodontitis (AgP) through susceptibility to oral dysbiosis and subsequent host-microbe interaction. This case-control study aimed to perform a multilocus analysis of functional variants in selected interleukin (IL) genes in patients with the generalized form of AgP in a homogenous population. Twelve polymorphisms in IL-1 gene cluster, IL-6 and its receptor, IL-10, IL-17A, and IL-18 were determined in 91 AgP patients and 210 controls. Analysis of seven selected periodontal bacteria in subgingival sulci/pockets was performed with a commercial DNA-microarray kit in a subgroup of 76 individuals. The pilot in vitro study included stimulation of peripheral blood monocytes (PBMC) from 20 individuals with periodontal bacteria and measurement of IL-10 levels using the Luminex method. Only the unctional polymorphism IL-10 −1087 A/G (rs1800896) and specific IL-10 haplotypes were associated with the development of the disease (p < 0.05, P_corr > 0.05). Four bacterial species occurred more frequently in AgP than in controls (p < 0.01, P_corr < 0.05). Elevated IL-10 levels were found in AgP patients, carriers of IL-10 −1087GG genotype, and PBMCs stimulated by periodontal bacteria (p < 0.05, P_corr > 0.05). We therefore conclude that a combination of genetic predisposition to the altered expression of IL-10 and the presence of specific periodontal bacteria may contribute to Th1/Th2 balance disruption and AgP development.

Interleukin-1β (IL-1β) C-511T polymorphism is associated with susceptibility to coronary artery disease in type 2 diabetic patients

Variants of the interleukin-1β (IL-1β) gene have been associated with type 2 diabetes (T2D) and coronary artery diseases (CAD). However, association of IL-1β polymorphisms with diabetic patients having CAD clinical manifestation has not been studied yet. In this study, we aim to decipher the role of IL-1β common promoter variants with susceptibility/resistance to development of CAD in T2D patients. T2D patients with (n = 134) or without CAD (n = 533) were enrolled. A total of 513 essentially healthy individuals from the same population were included in this study as control. Plasma levels of IL-1β were quantified by enzyme-linked immunosorbent assay (ELISA) kit as per instructions from the manufacturer. IL-1β promoter variants (T-31C and C-511T) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). T2D patients displayed higher level of plasma IL-1β in comparison to healthy controls. Prevalence of variants for IL-1β (C-511T) polymorphism was higher in diabetic patients compared to controls (CT: P < 0.0001, OR = 3.01; TT: P < 0.0001, OR = 2.45). IL-1β (C-511T) polymorphism was linked with plasma IL-1β levels. Interestingly, heterozygous mutants (CT) were most prevalent in T2D individuals with CAD compared to those without CAD ( P = 0.03, OR = 1.82). Furthermore, low-density lipoprotein (LDL) and triglycerides were elevated in T2D patients with CAD than in patients without heart-related disorder. No significant association of other polymorphism (T-31C) was noticed with susceptibility to T2D or diabetic patients with heart disorders. IL-1β (C-511T) variants are associated with elevated plasma IL-1β levels. Mutation at the IL-1β promoter region (C-511T) predisposed subjects to the development of T2D and CAD manifestation in diabetic patients.

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.