Correlation between SNP genotypes and periodontitis in Japanese type II diabetic patients: a preliminary study

Evaluation of the Genetic Association and Methylation of Immune Response Pathway Genes with the Risk of Chronic Periodontitis in the Uighur Population

Aim: The aim of this study was to explore the possible associations between single nucleotide polymorphisms (SNPs) and DNA methylation levels of seven genes in the inflammatory response pathway with susceptibility to chronic periodontitis (CP) among the Uighur population of the Xinjiang Autonomous Region of China. Methods: A total of 444 eligible subjects (279 CP patients and 165 healthy controls) were enrolled in the study. Genomic DNA was obtained from gingival tissue for genotyping eight SNPs and performing methylation measurements of seven genes. Results: SNP rs2070745 in the formyl peptide receptor 1 (FPR1) gene achieved statistical significance in a standard allelic association analysis for CP (p = 0.02). The frequency of the rs2070745 minor allele G was higher in the cases than in controls (0.367 vs. 0.291). Additionally, rs2070745 was significantly associated with CP under the dominant genetic model (p = 0.03). Using logistic regression analysis, rs2070745 was found to be consistently associated with CP under the additive dominant model, and this association remained significant after covariates were taken into account [odds ratio (OR) = 1.49 (1.09-2.05), p = 0.014; OR = 1.58 (1.04-2.40), p = 0.031, respectively]. No significant gene-gene interactions were identified. Although we did not find a polymorphism in interleukin 6 (IL6) associated with CP in our study, the methylation level of a CpG island region located within the promoter region of IL6 was significantly less in CP patients compared with controls (p < 0.05). Conclusions: The genetic polymorphism rs2070745 in FPR1 and the methylation level of the promoter region of IL6 might be associated with CP in the Uighur population of China.

Adipokine gene variability and plasma levels in patients with chronic periodontitis -a case-control study

Specific variants in genes that encode adipokines and their mRNA and protein expression were previously studied in type 2 diabetes mellitus (T2DM) and obesity, and similar studies have been performed for chronic periodontitis (CP). The aim of this case-control study was to investigate the possible impacts of adiponectin (ADIPOQ), leptin (LEP) and its receptor (LEPR), and resistin (RETN) on the etiopathogenesis of CP. Examinations were performed on 118 non-periodontitis healthy subjects (healthy controls, HC), 205 healthy individuals with CP (H + CP) and 86 type 2 diabetes patients with CP (T2DM + CP). Variants within the ADIPOQ (rs2241766, rs1501299), LEP (rs13228377, rs2167270), LEP receptor (rs1805096), and RETN (rs1862513) genes were determined by qPCR. In addition, the plasma levels of ADIPOQ, LEP, and RETN were analysed by ELISA for 80 individuals. The genotype frequencies of the SNP ADIPOQ +45G/T (rs2241766) differed between the HC and H + CP groups (p=0.03, pcorr>0.05), and carriers of the TT genotype had a lower risk of developing CP compared to carriers of the GG or TG genotypes (p<0.01, pcorr>0.05). However, there were no significant differences in the plasma levels of ADIPOQ, LEP or RETN between the study groups (p > 0.05). Plasma levels of the adipokines were also independent of the gene profiles (p > 0.05). Adipokine plasma levels did not change in patients with H + CP/T2DM + CP compared to HC, but we did identify a specific polymorphism in the ADIPOQ gene that was associated with CP. Although the ADIPOQ +45G/T (rs2241766) gene variant may be a candidate biomarker for CP, further research is required in larger populations with different ethnic backgrounds before any final conclusions can be drawn about the role of this gene in CP.