Evidence Linking PPARG Genetic Variants with Periodontitis and Type 2 Diabetes Mellitus in a Brazilian Population.

The peroxisome proliferator-activated receptor gamma (PPARG) gene encodes a transcription factor involved in the regulation of complex metabolic and inflammatory diseases. We investigated whether single nucleotide polymorphisms (SNPs) and haplotypes of the PPARG gene could contribute with susceptibility to develop periodontitis alone or together with type 2 diabetes mellitus (T2DM). Moreover, we evaluated the gene-phenotype association by assessing the subjects' biochemical and periodontal parameters, and the expression of PPARG and other immune response-related genes. We examined 345 subjects with a healthy periodontium and without T2DM, 349 subjects with moderate or severe periodontitis but without T2DM, and 202 subjects with moderate or severe periodontitis and T2DM. PPARG SNPs rs12495364, rs1801282, rs1373640, and rs1151999 were investigated. Multiple logistic regressions adjusted for age, sex, and smoking status showed that individuals carrying rs1151999-GG had a 64% lower chance of developing periodontitis together with T2DM. The CCGT haplotype increased the risk of developing periodontitis together with T2DM. The rs1151999-GG and rs12495364-TC were associated with reduced risk of obesity, periodontitis, elevated triglycerides, and elevated glycated hemoglobin, but there was no association with gene expression. Polymorphisms of the PPARG gene were associated with developing periodontitis together with T2DM, and with obesity, lipid, glycemic, and periodontal characteristics.

Polymorphisms in risk genes of type 2 diabetes mellitus could be also markers of susceptibility to periodontitis.

OBJECTIVES: This study aimed to investigate polymorphisms in genes considered molecular biomarkers of type 2 diabetes mellitus (T2DM) to assess whether they are associated with periodontitis, and relating them to the periodontal status, glycemic and lipid profile of the subjects. DESIGN: We investigated individuals who underwent complete periodontal examination and biochemical evaluation. We categorized them into three groups: (i) periodontitis with T2DM (Periodontitis+T2DM group, n = 206); (ii) periodontitis without T2DM (Periodontitis group, n = 346); and (iii) healthy individuals without Periodontitis or T2DM (Healthy group, n = 345). We investigated three single nucleotide polymorphisms (SNPs) for AGER, RBMS1 and VEGFA genes. We applied multivariate logistic and multiple linear regression models for all groups and stratified the subjects by sex and smoking habits. RESULTS: Compared with RBMS1-rs7593730-CC+CT genotype carriers, RBMS1-rs7593730-TT carriers were more susceptible to periodontitis [odds ratio (OR) = 2.29; 95% confidence interval (CI) = 1.04-5.01; P-value = 0.033]. Among AGER-rs184003-CC carriers, never smokers had reduced risks of periodontitis and Periodontitis+T2DM than ever smokers. For either RBMS1-rs7593730-CC or VEGFA-rs9472138-CC carriers, never smokers had less susceptibility to develop periodontitis than ever smokers. Compared with AGER-rs184003-CC carriers, AGER-rs184003-AA carriers presented fewer remaining teeth. VEGFA-rs9472138-TT carriers showed a lower percentage of sites with characteristics of active periodontal disease (bleeding on pocket probing and interproximal clinical attachment level) compared with VEGFA-rs9472138-CC carriers. CONCLUSIONS: In the studied population, AGER rs184003, RBMS1 rs7593730, and VEGFA rs9472138, which are considered genetic markers for T2DM, were associated with periodontitis without T2DM or periodontitis together with T2DM.

Polymorphisms in Genes of Lipid Metabolism Are Associated with Type 2 Diabetes Mellitus and Periodontitis, as Comorbidities, and with the Subjects' Periodontal, Glycemic, and Lipid Profiles.

BACKGROUND: Type 2 diabetes mellitus (T2DM) and periodontitis (P) commonly occur as comorbidities, but the commonalities in the genetic makeup of affected individuals is largely unknown. Since dyslipidemia is a frequent condition in these individuals, we investigate the association of genomic variations in genes involved in lipid metabolism with periodontal, glycemic, lipid profiles, and the association with periodontitis and T2DM (as comorbidities). METHODS: Based on clinical periodontal examination and biochemical evaluation, 893 subjects were divided into T2DM+P (T2DM subjects also affected by periodontitis, n = 205), periodontitis (n = 345), and healthy (n = 343). Fourteen single-nucleotide polymorphisms (SNPs) were investigated: LDLR gene (rs5925 and rs688), APOB (rs676210, rs1042031, and rs693), ABCC8 (rs6544718 and 6544713), LPL (rs28524, rs3735964, and rs1370225), HNF1A (rs2650000), APOE (rs429358 and rs7412), and HNF4A (rs1800961). Multiple linear and logistic regressions (adjusted for covariates) were made for all populations and stratified by sex and smoking habits. RESULTS: Individuals carrying APOB-rs1042031-CT (mainly women and never smokers) had a lower risk of developing periodontitis and T2DM (T2DM+P); altogether, this genotype was related with healthier glycemic, lipid, and periodontal parameters. Significant disease-phenotype associations with gene-sex interaction were also found for carriers of APOB-rs1676210-AG, HNF4A-rs1800961-CT, ABCC8-rs6544718-CT, LPL-rs13702-CC, and LPL-rs285-CT. CONCLUSIONS: Polymorphisms in lipid metabolism genes are associated with susceptibility to T2DM-periodontitis comorbidities, demonstrating gene-sex interaction. The APOB-rs1042031 was the most relevant gene marker related to glucose and lipid metabolism profiles, as well as with obesity and periodontitis.

Polymorphisms and haplotypes in the Interleukin 17 Alfa gene: potential effect of smoking habits in the association with periodontitis and type 2 diabetes mellitus.

Few studies evaluate interrelationships between periodontitis (P) and Type 2 Diabetes Mellitus (T2DM). The aim of this study is to investigate the genetic susceptibility to periodontitis alone, or concomitant with T2DM (as comorbidities), analyzing single nucleotide polymorphisms (SNPs) in the Interleukin 17 alpha (IL17A) gene, considering the biochemical profile and smoking habits on the subjects' periodontal status. We investigated 879 individuals divided into: T2DM subjects also affected by severe or moderate periodontitis (T2DM-P, n = 199); non-diabetics with severe or moderate periodontitis (PERIODONTITIS, n = 342); and healthy subjects (HEALTHY, n = 338). Subjects underwent complete periodontal examination, history of smoking habits, glycemic and lipid biochemical evaluation. DNA from buccal cells was utilized to genotype the SNPs rs2275913, rs3819024 and rs10484879. The impact of the subjects' biochemical profile was analyzed in their periodontal status. Each SNP was analyzed independently, and as haplotypes, by multiple logistic regressions, adjusted for covariates, and also stratifying the groups by age, sex and smoking habits. Independently of the periodontitis degree, poorly-controlled T2DM subjects showed worse glycemic and lipid profile. Multiple logistic regressions demonstrated that smokers and former-smokers carrying the GG genotype of rs3819024 seemed to have higher risk for T2DM-Periodontitis (OR = 6.33; 95% CI = 1.26-31.77, p = 0.02), and mainly for T2DM alone (OR = 5.11; 95% CI = 1.37-19.06, p = 0.01), than never smokers. We found the potential effect of smoking habits in the association of IL17A-rs3819024-GG with diseased phenotypes. Because the observed wide confidence intervals, further studies enrolling larger populations, and SNPs' functional evaluations are needed to better understand our findings.

Association of type 2 diabetes mellitus and periodontal disease susceptibility with genome-wide association-identified risk variants in a Southeastern Brazilian population.

OBJECTIVE: Genome-wide association studies (GWAS) and literature have identified polymorphisms in the KCNJ11, HNF1A, IRS1, TCF7L2, CDKAL1, CDKN2B, RPSAP52, GPR45 HHEX, IL18, and RUNX2 genes associated with type 2 diabetes mellitus (T2DM) and/or periodontitis (P) in diverse populations, and we sought to evaluate them as genetic risk variants for these diseases in the Brazilian population. MATERIAL AND METHODS: Periodontal, glycemic, and lipid data were obtained from 931 individuals divided into: control (n = 334), periodontitis (P; n = 358), and periodontitis associated with T2DM (P + T2DM; n = 239). After genotyping, associations between polymorphisms and pathologies were tested by multiple logistic and linear regressions, adjusting for age, sex, and smoking habits. RESULTS: Considering the studied subjects, the increased risk to develop periodontitis in the periodontitis P + T2DM group was found for HNF1A-rs7957197-TA, CDKAL1-rs7754840-CG, RPSAP52-rs1531343-GC, TCF7L2-rs7903146-TT, and CDKN2B-rs7018475-GG. The association of these genetic variants for TCF7L2 and CDKN2B was confirmed for female, never smokers, and poorly controlled P + T2DM. CDKN2B-rs7018475 was associated with worse glycemic condition and periodontal parameters. CONCLUSION: These five reported genetic variants were associated in the studied Southeastern Brazilian population as genetic risk variants of periodontitis and T2DM associated to periodontitis as comorbidity. Gene-phenotype associations with sex and smoking habits and the CDKN2B-rs7018475 with the poor glycemic control and more severe periodontal conditions should be further investigated. CLINICAL RELEVANCE: Polymorphisms in the CDKAL1-rs7754840, HNF1A-rs7957197, RPSAP52-rs1531343, TCF7L2-rs7903146, and CDKN2B-rs7018475 might predispose to periodontitis and T2DM associated with periodontitis. These findings may be useful in public health genomics and future advanced clinical practice, since genetic carriage can be measured before disease onset, being of potential great benefit for treatment planning and prognosis in early disease stages.

Validation in a Brazilian population of gene markers of periodontitis previously investigated by GWAS and bioinformatic studies.

BACKGROUND: Bioinformatic tools and genome-wide association studies (GWAS) have led to comprehensive identification of single nucleotide polymorphisms (SNPs) associated with periodontitis in diverse populations. Here we aimed to detect and validate the association of seven SNPs as genetic markers of susceptibility to periodontitis in a Brazilian population. METHODS: This case-control study assessed complete periodontal parameters of 714 subjects with periodontal status classified as healthy/mild periodontitis (n = 356) and moderate/severe periodontitis (n = 358). Genotyping for rs187238, rs352140, rs1360573, rs2521634, rs3811046, rs3826782, and rs7762544 SNPs were evaluated. Genetic-phenotype associations, and sex or smoking effects of SNPs on periodontitis were tested using multiple logistic regressions adjusted for covariates. RESULTS: The rs2521634-AA (close to NPY gene) presented increased risk for severe periodontitis (OR = 2.34; 95% CI = 1.19-4.59). The rs3811046-GG (IL37 gene) demonstrated increased risk for moderate periodontitis (OR = 2.58; 95% CI = 1.28-5.18). Higher risk for moderate periodontitis was found in male with rs7762544-AG close to NCR2 gene. The rs352140-TT in the TLR9 gene proved to be associated with lower risk to severe periodontitis in men. The rs2521634-AA was associated with higher percentage of interproximal probing pocket depth (P = .004). CONCLUSIONS: This is the first evidence of validation in a Brazilian population of genetic markers of periodontitis previously investigated by GWAS and bioinformatics studies. SNPs in the NPY, IL37, and NCR2 genes were associated with susceptibility to moderate or severe periodontitis; whereas the TLR9 marker was associated with lower chance to develop severe periodontitis. Those SNPs had sex- and smoking-habit-specific effects on periodontitis; reinforcing the genetic profile predisposing to periodontitis.

Functional haplotype in the Interleukin8 (CXCL8) gene is associated with type 2 Diabetes Mellitus and Periodontitis in Brazilian population.

BACKGROUND AND AIM: Type 2 Diabetes Mellitus (T2DM) and Periodontitis (P) are prevalent multifactorial disorders worldwide, sharing a bidirectional relationship influenced by the genetic susceptibility of the host immune system. We investigated whether SNPs in the Interleukin 8 (IL8, alias CXCL8) gene could be associated with T2DM and Periodontitis. METHODS: Genomic DNA was obtained from 874 Brazilian individuals divided into: Healthy group (n = 307), Periodontitis group (n = 334), and individuals affected by both T2DM and Periodontitis (T2DM_P) group (n = 233). The SNPs -251(T>A) rs4073, +396(T>G) rs2227307 and +781(C>T) rs2227306 were genotyped by TaqMan®. Multiple logistic regressions were used to determine the degree of association between polymorphisms (and haplotypes) with periodontitis and T2DM adjusted for known confounders. RESULTS: The additive model revealed that the heterozygous AT(-251), GT(+396) and CT(+781) genotypes showed a lower risk for the diseased phenotypes, and carriers of the TTC/TTC haplotype were significantly susceptible to T2DM and Periodontitis concomitantly, as well to isolated Periodontitis (mainly the severe form). CONCLUSIONS: We concluded, for the first time, that these functional CXCL8 SNPs, and the homozygous TTC haplotype are relevant genetic factors for T2DM and Periodontitis as comorbidities, as well as for severe Periodontitis susceptibility in Brazilian population.

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.

Circulating lymphocytes and monocytes transcriptomic analysis of patients with type 2 diabetes mellitus, dyslipidemia and periodontitis.

Type 2 diabetes mellitus (T2DM), dyslipidemia and periodontitis are frequently associated pathologies; however, there are no studies showing the peripheral blood transcript profile of these combined diseases. Here we identified the differentially expressed genes (DEGs) of circulating lymphocytes and monocytes to reveal potential biomarkers that may be used as molecular targets for future diagnosis of each combination of these pathologies (compared to healthy patients) and give insights into the underlying molecular mechanisms of these diseases. Study participants (n = 150) were divided into groups: (H) systemically and periodontal healthy (control group); (P) with periodontitis, but systemically healthy; (DL-P) with dyslipidemia and periodontitis; (T2DMwell-DL-P) well-controlled type 2 diabetes mellitus with dyslipidemia and periodontitis; and (T2DMpoorly-DL-P) poorly-controlled type 2 diabetes mellitus with dyslipidemia and periodontitis. We preprocessed the microarray data using the Robust Multichip Average (RMA) strategy, followed by the RankProd method to identify candidates for DEGs. Furthermore, we performed functional enrichment analysis using Ingenuity Pathway Analysis and Gene Set Enrichment Analysis. DEGs were submitted to pairwise comparisons, and selected DEGs were validated by quantitative polymerase chain reaction. Validated DEGs verified from T2DMpoorly-DL-P versus H were: TGFB1I1, VNN1, HLADRB4 and CXCL8; T2DMwell-DL-P versus H: FN1, BPTF and PDE3B; DL-P versus H: DAB2, CD47 and HLADRB4; P versus H: IGHDL-P, ITGB2 and HLADRB4. In conclusion, we identified that circulating lymphocytes and monocytes of individuals simultaneously affected by T2DM, dyslipidemia and periodontitis, showed an altered molecular profile mainly associated to inflammatory response, immune cell trafficking, and infectious disease pathways. Altogether, these results shed light on novel potential targets for future diagnosis, monitoring or development of targeted therapies for patients sharing these conditions.

Serum lipid levels in patients with periodontal disease: A meta-analysis and meta-regression.

AIM: Several papers have considered the potential relationship between periodontitis and lipid parameters. The present systematic review, meta-analysis and meta-regression studies focused on investigating whether serum lipid parameter levels were elevated in patients with periodontal disease (PD; without altered systemic conditions) in comparison with periodontally healthy subjects. MATERIALS AND METHODS: Eligible studies were those with data about serum lipid parameter levels in non-smoking subjects with and without chronic periodontitis, who are generally healthy and not taking any medication for dyslipidaemia. Mean differences and 95% confidence intervals for total cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were obtained from all the selected studies. RESULTS: A total of 19 publications were included for meta-analysis. Participants with chronic periodontitis presented significantly higher serum levels of LDL and triglycerides (p = .003 and p < .0001, respectively). The total cholesterol was higher in the PD group, but without significant difference in comparison with healthy participants. Significantly (p = .0005) lower HDL serum levels were found in patients with chronic periodontitis than in healthy subjects. CONCLUSIONS: Even considering the limitations of this meta-analysis, it is suggested that PD is significantly associated with reduction in HDL and elevation of LDL and triglyceride concentrations. This analysis supports the rationale that periodontal disease is associated with lipid metabolic control.

Ultrastructural assessment of the radioprotective effects of sodium selenite on parotid glands in rats.

The aim of this study was to assess the radioprotective effects of sodium selenite on parotid glands in rats by ultrastructural analysis of acinar cells. Four experimental groups were assessed; control, irradiated, selenium, and selenium/irradiated. The sodium selenite dose was 0.5 mg/kg, administered intraperitoneally 24 h before irradiation in the head and neck region with a single 15-Gy dose of gamma radiation. At 4, 8, 12, 48 and 72 h after irradiation, all animals were sacrificed and the parotid glands were removed. Radiation caused cellular changes from 4 h, and the organelles that presented the greatest alterations were the mitochondria and the secretion glands; nuclear alterations were also observed. Sodium selenite was found to have a radioprotective action, as the selenium/irradiated group presented with less damage when compared to the irradiated group. However, sodium selenite caused cellular alterations that were evident after 8 h, but with less damage when compared to those caused by radiation, which demonstrates a favorable risk-benefit for its use as a radioprotector. Thus, this research shows that sodium selenite has an effective radioprotective action in the parotid gland, which may contribute to the reduction of the adverse effects brought by the radiotherapy.

The Influence of Nicotine on the bone loss rate in ligature-induced periodontitis. A histometric study in rats / A influência da nicotina na perda da taxa óssea nas contenções periodontais. Um estudo histométrico em ratos

Background: The present study investigated the possible influence of nicotine on the bone loss rate in the furcation region due to ligature-induced periodontitis rats. Methods: Twenty adult male Wistar rats were included. After anesthesia, the tooth was randomly assigned to receive the cotton ligature in the sulcular area, while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following treatments, including daily intraperitoneal injections: group A, 2 µl/g body weight of saline solution; group B, 2 µl/g body weight of a nicotine solution with 0.13 µl of nicotine/ml of saline solution; group C, 2 µl/g body weight of a nicotine solution with 0.19 µl of nicotine solution with 0.26 µl of nicotine/ml of saline solution. Thirty days later, the animals were sacrificed and the specimens routinely processed for serial decalcificed sections...

Eletromiografia do músculo masseter em casos de oclusäo normal e maloclusäo Classe I / Electromyography of the masseter muscle in normal occlusion and Angle Class I malocclusion

Os autores estudaram eletromiograficamente o músculo masseter em suas regiöes superior, média e inferior e verificaram a participaçäo de cada uma delas na realizaçäo de diferentes movimentos mandibulares, em indivíduos com oclusäo clinicamente normal e maloclusäo Classe I de Angle

Alteraçöes ultra-estruturais das fibras nervosas pulpares relacionadas com processo de cárie / Ultrastructural alterations of pulp nerve fibers related to caries process

Este trabalho buscou avaliar as alteraçöes morfológicas ultra-estruturais das fibras nervosas pulpares em diversos estágios do processo de cárie. Foi feita também uma correlaçäo entre os dados ultra-estruturais e a sintomatologia referida pelos pacientes em cada caso. Os dentes foram clivados e foi feita remoçäo do tecido pulpar, que foi fracionado e fixado em glutaraldeído. O material foi processado seguindo técnicas de rotina para microscopia eletrônica de transmissäo. Foram encontradas diferenças no que se refere ao estágio da cárie e às alteraçöes das fibras nervosas, indicando que as mielínicas säo as que primeiro sofrem com a lesäo, chegando a processos degenerativos, sendo que estas responderiam por dor do tipo agudo. As fibras amielínicas mostraram um menor grau de alteraçäo e parecem ser responsáveis pela dor pulpar do tipo crônica