Association of Haplotypes in the CXCR2 Gene with Periodontitis in a Brazilian Population

Associations between Single Nucleotide Polymorphisms from the Genes of Chemokines and the CXCR2 Chemokine Receptor and an Increased Risk of Endometrial Cancer

Significant relationships with endometrial cancer were demonstrated, both for CCL2, CCL5, and CXCL8 chemokines and for the chemokine receptor CXCR2. The reported case-control study of genetic associations was designed to establish the role of selected single nucleotide polymorphisms (SNPs) of the CCL2, CCL5, CXCL8, and CXCR2 genes in the onset and progression of endometrial cancer. This study was conducted on 282 women, including 132 (46.8%) patients with endometrial cancer and 150 (53.2%) non-cancerous controls. The genotypes for CCL2 rs4586, CCL5 rs2107538 and rs2280789, CXCL8 rs2227532 and -738 T>A, and CXCR2 rs1126580 were determined, using PCR-RFLP assays. The AA homozygotes in CCL5 rs2107538 were associated with more than a quadruple risk of endometrial cancer (p ≤ 0.050). The GA heterozygotes in the CXCR2 SNP were associated with approximately threefold higher cancer risk (p ≤ 0.001). That association also remained significant after certain adjustments, carried out for age, diabetes mellitus, arterial hypertension, or endometrial thickness above 5 mm (p ≤ 0.050). The A-A haplotypes for the CCL5 polymorphisms and T-A-A haplotypes for the CCL2 and CCL5 SNPs were associated with about a twofold risk of endometrial cancer (p ≤ 0.050). In conclusion, CCL2 rs4586, CCL5 rs2107538 and rs2280789, and CXCR2 rs1126580 demonstrated significant associations with an increased risk of endometrial cancer.

Periodontitis association with IL-8 gene polymorphisms

IL-8 and its polymorphisms are involved in multiple acute and chronic inflammatory processes including pathological changes to surrounding structures of the teeth called periodontal diseases or periodontitis. The aim of this manuscript was to systematically review studies from 2006 to 2021 on IL-8 polymorphisms and their association with periodontitis. Literature analysis was done following the PRISMA protocol guidance using articles not older than 15 years (2006-2021). The search was carried out using PubMed (MEDLINE), ScienceDirect and Wiley Online Library databases. For the focus question, the PICO (population (P), intervention (I), control (C), and outcome (O)) study design protocol was used, and the following question was formulated: are IL-8 gene polymorphisms associated with periodontitis? A total of 2422 articles were found at the beginning of the search. After applying the inclusion and exclusion criteria, screening, and full-text article exclusion with reasons, 31 studies were included in the analysis. In conclusion, IL-8 and its gene polymorphisms are associated with an increased risk of periodontal diseases.

Association of single nucleotide polymorphisms in CXCR1, CXCR2 and CXCL5 with Behçet disease: a study in the Denizli province of Turkey

BACKGROUND

Behçet disease (BD) is associated with the immune system, especially neutrophilic activity. The CXCR1, CXCR2 and CXCL5 genes mediate the activation and migration of neutrophils.

AIM

To investigate CXCR1, CXCR2 and CXCL5 single nucleotide polymorphisms (SNPs) and examine their association with BD.

METHODS

We studied polymorphic sites in CXCR1 (four sites: rs16858811, rs9282752, rs16858809 and rs16858808), CXCR2 (three sites: rs2230054, rs1126579 and rs1126580) and CXCL5 (one site: rs352046) in 87 patients with BD and 111 healthy controls (HCs), using a PCR restriction-fragment length polymorphism-based approach for genotyping.

RESULTS

We found that the CXCR2 rs2230054 TT genotype and the CXCL5 rs352046 polymorphism might be possible genetic factors responsible for BD. We did not find any association between the development of BD and any of the four CXCR1 polymorphisms or the other two CXCR2 SNPs. In addition, our haplotype analysis results indicated that the haplotypes of the CXCR2 and CXCR1-CXCR2 polymorphic loci were different between the BD and HC groups.

CONCLUSION

Our study suggests that polymorphisms of CXCR1, CXCR2 and CXCL5 may affect susceptibility to BD and increase the risk of developing the disease. These loci need to be studied in larger groups of patients from different geographical areas around the world in order to clarify the genetic background for BD pathogenesis.

Chemokine Receptor 2 (CXCR2) Gene Polymorphisms and Their Association with the Risk of Developing Peri-Implantitis in Chinese Han Population

Purpose

This study aimed to investigate the role of chemokine receptor 2 (CXCR2) gene polymorphisms in peri-implantitis susceptibility in a Chinese Han population.

Patients and Methods

A total of 260 individuals were included in this study, including 127 peri-implantitis patients and 133 healthy implants. CXCR2 gene rs2230054 and rs1126580 polymorphisms in different groups were analyzed by the Chi-square test. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were employed to evaluate the association between CXCR2 polymorphism and peri-implantitis susceptibility.

Results

The CT genotype of rs2230054 and the AG genotype and G allele of rs1126580 significantly increased in peri-implantitis patients compared with healthy implants (P < 0.05). The CT genotype of rs2230054 (OR = 1.825, 95% CI = 1.028–3.239) and the AG genotype of rs1126580 (OR = 2.223, 95% CI 1.272–3.885) carriers had a high risk to infect with peri-implantitis. Additionally, these CXCR2 gene polymorphisms have been revealed to be associated with the periodontal status of peri-implantitis patients.

Conclusion

The CXCR2 gene rs2230054 and rs1126580 polymorphisms were associated with the peri-implantitis susceptibility in the Chinese Han population. The CT genotype of rs2230054 and the AG genotype and G allele of rs1126580 serve as risk factors for the occurrence of peri-implantitis.

Chemokine Receptor 2 (CXCR2) Gene Variants and Their Association with Periodontal Bacteria in Patients with Chronic Periodontitis

Periodontitis, an inflammatory disease caused by subgingival Gram-negative (G-) bacteria, is linked with loss of the connective tissue and destruction of the alveolar bone. In the regulation of inflammatory response, chemokine receptor 2 (CXCR2), a specific receptor for interleukin-8 and neutrophil chemoattractant, plays an important role. The first aim of this study was to investigate the CXCR2 gene variability in chronic periodontitis (CP) patients and healthy nonperiodontitis controls in the Czech population. The second aim was to find a relation between CXCR2 gene variants and the presence of periodontal bacteria. A total of 500 unrelated subjects participated in this case-control study. 329 CP patients and 171 healthy nonperiodontitis controls were analyzed using polymerase chain reaction techniques for three single-nucleotide polymorphisms (SNPs): +785C/T (rs2230054), +1208T/C (rs1126579), and +1440A/G (rs1126580). A DNA microarray detection kit was used for the investigation of the subgingival bacterial colonization, in a subgroup of CP subjects (N = 162). No significant differences in allele, genotype, haplotype, or haplogenotype frequencies of CXCR2 gene variants between patients with CP and healthy controls (P > 0.05) were determined. Nevertheless, Aggregatibacter actinomycetemcomitans was detected more frequently in men positive for the C allele of the CXCR2 +785C/T polymorphism (61.8% vs. 41.1%, P < 0.05; OR = 2.31, 95% CI = 1.03-5.20) and for the T allele of the CXCR2 +1208C/T variant (61.8% vs. 38.9%, P < 0.05; OR = 2.54, 95% CI = 1.13-5.71). In contrast, no statistically significant associations of CXCR2 variants with seven selected periodontal bacteria were found in women. Although none of the investigated SNPs in the CXCR2 gene was associated with CP, the CXCR2 gene variants can be associated with subgingival colonization of G- bacteria in men with CP in the Czech population.

Comprehensive analysis of interleukin-8 gene polymorphisms and periodontitis susceptibility

Background

Associations between interleukin-8 (IL-8) gene polymorphisms and periodontitis susceptibility have been investigated in many published studies, but the conclusions are still inconsistent. Therefore, we performed this systematic review and meta-analysis to review which polymorphisms have been researched and to obtain a precise result of the same polymorphism from different studies.

Results

Finally 10 publications involving 1938 patients and 1569 controls were yielded, including 12 polymorphisms. Six studies investigated rs4073 polymorphism; two focused on rs2227306 and rs2227307; two referred to rs2227532 and T-738A; one detected rs2230054, rs1126579 and rs1126580; one inspected A2767T, T₁1722T₂ and C1633T, and one for rs2234671 polymorphism. Of them, IL-8 C1633T and rs1126580 polymorphisms showed positive association while the other ten polymorphisms revealed negative results.

Materials and methods

A comprehensive literature search from PubMed, Web of Science, and Chinese National Knowledge Infrastructure was conducted for all potentially relevant studies published before January 2, 2017. Two authors selected the studies and extracted data. The pooled analysis was conducted using the RevMan 5.1 software if a polymorphism was reported by two or more studies.

Conclusions

Based on current evidence, the IL-8 rs4073, A2767T, T₁1722T₂, rs2234671, rs2230054, rs1126579, rs2227306, rs2227307, rs2227532, and T-738A polymorphisms were not associated with periodontitis susceptibility; the IL-8 C1633T and rs1126580 polymorphisms were associated with increased risk of periodontitis.

Inducible Nitric Oxide Synthase Polymorphisms and Nitric Oxide Levels in Individuals with Chronic Periodontitis

This study aimed to investigate whether the -1026(A>C)(rs2779249) and +2087(A>G)(2297518) polymorphisms in the NOS2 gene were associated with chronic periodontitis (CP) and with salivary levels of nitrite (NO₂^-) and/or nitrate + nitrite (NOx). A group of 113 mixed-race patients were subjected to periodontal, genetic, and biochemical evaluations (65 CP/48 periodontally healthy subjects). DNA was extracted from oral epithelial cells and used for genotyping by polymerase chain reaction (real-time). Salivary NOx concentrations were determined using an ozone-based chemiluminescence assay. Association of CP with alleles and genotypes of the -1026(A>C) polymorphism was found (X² test, p = 0.0075; 0.0308), but this was not maintained after multiple logistic regression, performed to estimate the effect of covariates and polymorphisms in CP. This analysis demonstrated, after correction for multiple comparisons, that only the female gender was significantly associated with CP. Polymorphisms analyzed as haplotypes were not associated with CP. NOx levels were significantly higher in the control group of heterozygous individuals for both polymorphisms. In conclusion, the female gender was significantly associated with CP, and higher levels of salivary NOx were found in control subjects and associated with the heterozygous state of the NOS2 polymorphisms, reinforcing the potential of NO metabolites as markers of periodontitis status.

Genome-wide association studies of pit-and-fissure- and smooth-surface caries in permanent dentition

While genetics clearly influences dental caries risk, few caries genes have been discovered and validated. Recent studies have suggested differential genetic factors for primary dentition caries and permanent dentition caries, as well as for pit-and-fissure- (PF) and smooth- (SM) surface caries. We performed separate GWAS for caries in permanent-dentition PF surfaces (1,017 participants, adjusted for age, sex, and the presence of Streptococcus mutans) and SM surfaces (1,004 participants, adjusted for age, education group, and the presence of Streptococcus mutans) in self-reported whites (ages 14 to 56 yrs). Caries scores were derived based on visual assessment of each surface of each tooth; more than 1.2 million SNPs were either successfully genotyped or imputed and were tested for association. Two homologous genes were suggestively associated: BCOR (Xp11.4) in PF-surface caries (p value = 1.8E-7), and BCORL1 (Xq26.1) in SM-surface caries (p value = 1.0E-5). BCOR mutations cause oculofaciocardiodental syndrome, a Mendelian disease involving multiple dental anomalies. Associations of other plausible cariogenesis genes were also observed for PF-surface caries (e.g., INHBA, p value = 6.5E-6) and for SM-surface caries (e.g., CXCR1 and CXCR2, p value = 1.9E-6). This study supports the notion that genes differentially affect cariogenesis across the surfaces of the permanent dentition, and nominates several novel genes for investigation.

Association of chemokine gene variants with end stage renal disease in North Indian population

BACKGROUND & AIM

The progression rate of chronic kidney disease (CKD) to its end-stage renal disease (ESRD), and the development and severity of various complications, are indirectly influenced by genetic and epigenetic factors. Chemokines are small inducible pro-inflammatory cytokines, which are implicated in many biological processes like migration of leukocytes, angiogenesis, tumor growth and metastasis. We tested association of four single nucleotide polymorphisms (SNPs) viz. CCL2I/D, CCL2A2518G, CXCL12G801A and CXCR2(+1208)C/T among individuals with ESRD (end stage renal disease) and normal healthy controls from North Indian population.

MATERIALS AND METHOD

CCL2I/D, CCL2A2518G, CXCL12G801A and CXCR2(+1208)C/T were genotyped in blood samples of hospital-based case-control study comprising of 200 ESRD cases and 200 healthy controls using Restriction Fragment Length Polymorphism (RFLP) and ARMS (Amplification Refractory Mutation Specific) PCR methodology.

RESULTS

A significant association was found in CXCL12G801A with ESRD risk. In case of CXCL12G801A polymorphism heterozygous (GA) genotype showed significant risk (p=0.039; OR=1.55) whereas A allele carrier (GA+AA) also exhibited risk with ESRD (p=0.045, OR=1.59). In CXCR2(+1208)C/T polymorphism, the heterozygous genotype (CT) showed significant risk for ESRD (p=0.028; OR=1.65) and combination of CT+TT demonstrated significant high risk for ESRD (p=0.036; OR=1.52). In case of CCL2I/D, the variant genotype (D/D) showed reduced risk for ESRD patients. Upon analyzing the gene-gene interaction between CXCR2 and CXCL12, the combination (CT-GA) showed 2.65 fold risk for ESRD (p=0.018).

CONCLUSION

Our results indicated that polymorphism in CXCL12G801A and CXCR2(+1208)C/T showed high risk for ESRD in North Indian population. However, CCL2I/D showed reduced risk and CCL2A2518G exhibited no association. Study with large sample size and diverse ethnicity is required to validate these observations.

Variation in the CXCR1 gene (IL8RA) is not associated with susceptibility to chronic periodontitis

Background

The chemokine receptor 1 CXCR-1 (or IL8R-alpha) is a specific receptor for the interleukin 8 (IL-8), which is chemoattractant for neutrophils and has an important role in the inflammatory response. The polymorphism rs2234671 at position Ex2+860G > C of the CXCR1 gene causes a conservative amino acid substitution (S276T). This single nucleotide polymorphism (SNP) seemed to be functional as it was associated with decreased lung cancer risk. Previous studies of our group found association of haplotypes in the IL8 and in the CXCR2 genes with the multifactorial disease chronic periodontitis. In this study we investigated the polymorphism rs2234671 in 395 Brazilian subjects with and without chronic periodontitis.

Findings

Similar distribution of the allelic and genotypic frequencies were observed between the groups (p > 0.05).

Conclusions

The polymorphism rs2234671 in the CXCR1 gene was not associated with the susceptibility to chronic periodontitis in the studied Brazilian population.