Genetic polymorphism of interleukins 6 and 17 correlated with apical periodontitis: A Cross-sectional study.

Interleukins 6 and 17 act in bone resorption in the presence of infections of endodontic origin for host defense. Genetic polymorphisms may be associated with increased bone loss, represented by areas of large periapical lesions. This study aimed to verify the frequency of interleukin 6 and 17 gene polymorphism in patients with asymptomatic apical periodontitis or chronic apical abscess and to verify the existence of correlations between periapical lesion area with age, gender, and presence of the polymorphism, in the studied population, in the state of Pernambuco. A population consisting of thirty diagnosed individuals was included. The area of the lesions was measured in mm². Genomic DNA was extracted and genotyping was performed by Polymerase Chain Reaction Restriction Fragment Length Polymorphism for interleukin 6 (rs 1800795) and interleukin 17 (rs 2275913). Fisher's exact, chi-square, and odds ratio tests were used. A logistic regression analysis was also performed using sex, age, and the presence of polymorphism as covariates, in addition to linear regression to test the relationship between age and lesion area. All tests used a significance level of 0.05% (p ≤0.05%). There was no statistical significance in the occurrence of large areas of periapical lesions correlated with age, sex, and diagnosis, nor in the distribution of alleles in the polymorphism of interleukins 6 and 17 in the studied groups. The frequency of homozygous and heterozygous polymorphism was high. The polymorphism of these interleukins is not correlated with the increase in the areas of asymptomatic periapical inflammatory lesions.

Ferroptosis of macrophages facilitates bone loss in apical periodontitis via NRF2/FSP1/ROS pathway.

Apical periodontitis (AP) is an infectious disease that causes periapical tissue inflammation and bone destruction. Ferroptosis, a novel type of regulated cell death, is closely associated with inflammatory diseases and the regulation of bone homeostasis. However, the exact involvement of ferroptosis in the bone loss of AP is not fully understood. In this study, human periapical tissues were collected, and a mouse model was established to investigate the role of ferroptosis in AP. Colocalization staining revealed that ferroptosis in macrophages contributes to the inflammatory bone loss associated with AP. A cell model was constructed using RAW 264.7 cells stimulated with LPS to further explore the mechanism underlying ferroptosis in macrophages upon inflammatory conditions, which exhibited ferroptotic characteristics. Moreover, downregulation of NRF2 was observed in ferroptotic macrophages, while overexpression of NRF2 upregulated the level of FSP1, leading to a reduction in reactive oxygen species (ROS) in macrophages. Additionally, ferroptotic macrophages released TNF-α, which activated the p38 MAPK signaling pathway and further increased ROS accumulation in macrophages. In vitro co-culture experiments demonstrated that the osteogenic ability of mouse bone marrow stromal cells (BMSCs) was suppressed with the stimulation of TNF-α from ferroptotic macrophages. These findings suggest that the TNF-α autocrine-paracrine loop in ferroptotic macrophages can inhibit osteogenesis in BMSCs through the NRF2/FSP1/ROS signaling pathway, leading to bone loss in AP. This study highlights the potential therapeutic value of targeting ferroptosis in the treatment of inflammatory bone diseases.

Interleukin 6 and Interleukin 1ß hypomethylation and overexpression are common features of apical periodontitis: A case-control study with gingival tissue as control.

OBJECTIVES: Apical periodontitis is a periradicular tissue disorder that usually arises from infection by microorganisms in the root canal system resulting in local bone resorption. This usually involves the dysregulation of inflammatory mediators, which can be mediated by epigenetic mechanisms. Thus, the objective of this study was to evaluate Interleukin 6 (IL6) and Interleukin 1ß (IL1ß) and DNA methylation and gene expression levels in apical periodontitis. METHODS: Gene expression was analyzed in 60 participants using quantitative polymerase chain reaction, while the methylation levels of IL6 and IL1ß promoters were analyzed in 72 patients using pyrosequencing. All statistical analyzes were performed using the GraphPad Prism software version 8.0. The p value was considered statistically significant when < 0.05. RESULTS: A significantly higher IL6 and IL1ß expression levels were observed in cases relative to controls (fold-changes of 27.4 and 11.43, respectively, and p < 0.0001). By comparing the same groups, lower promoter methylation levels were observed for both genes in cases (methylation percentage delta relative to controls of -24.57% and -16.02%, respectively, and p < 0.0001). A significant inverse correlation between gene expression and promoter methylation was observed for both IL6 (p = 0.0002) and IL1ß (p = 0.001). Neither IL6 expression nor promoter methylation were significantly associated with cases' age, smoking history, alcohol consumption history or sex. For IL1ß, alcoholic cases showed lower methylation level relative to non-alcoholic cases (p = 0.01), while females showed higher methylation levels relative to males (p = 0.03). CONCLUSIONS: Our data suggest a role for DNA methylation in IL6 and IL1ß upregulation in apical periodontitis.

TNFSF13B rs9514828 gene polymorphism and soluble B cell activating factor levels: Association with apical periodontitis.

AIM: The aim of this case-control study was to evaluate the association between the TNFSF13B rs9514828 (-871 C > T) polymorphism and soluble BAFF (sBAFF) in apical periodontitis (AP) patients. METHODOLOGY: Two hundred and sixty one healthy subjects (HS) and 158 patients with AP classified as: 46 acute apical abscess (AAA), 81 primary AP (pAP) and 31 secondary AP (sAP) patients were included. Genomic DNA (gDNA) was extracted from peripheral blood cells according to the salting out method. The TNFSF13B rs9514828 (NC_000013.11:g.108269025C > T) were identified using polymerase chain reaction (PCR) followed by restriction fragment length polymorphisms (RFLP). Serum sBAFF levels were measured by ELISA test. The chi-squared or Fisher's exact test was performed. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate the risk of AP associated with the rs9514828. The Mann-Whitney U test and Kruskal-Wallis analysis were used for non-normally distributed data. Differences were considered significant with a p-value <.05. RESULTS: No differences in the genotype/allele frequencies were shown between HS and patients with AAA. However, the TT genotype (OR = 2.68, 95% CI: 1.10-6.53; p = .025) and T allele (OR = 1.46, 95% CI: 1.00-2.12; p = .045) were associated with increased risk of pAP. In contrast, the minor allele T significantly decreased the risk of sAP (OR = 0.49, 95% CI: 0.024-0.99; p = .043). sBAFF serum levels were increased in AAA and pAP compared with HS (p < .01 and p = .021, respectively). The AAA patients had higher sBAFF serum levels than pAP (p = .034) and sAP (p < .01). CONCLUSIONS: These results suggest that the TNFSF13B rs9514828 (-871 C > T) polymorphism is associated with pAP susceptibility and that BAFF is a cytokine that might be involved in acute and chronic AP. The future exploration of the rs9514828 polymorphism in other AP cohorts is recommended.

Single nucleotide polymorphisms as a predisposing factor for the development of apical periodontitis-An umbrella review.

BACKGROUND: The interaction between heredity and different environmental factors in the modification of apical periodontitis (AP) susceptibility and prediction of its progression remain poorly elucidated. OBJECTIVES: This umbrella review aimed to (i) analyse the available relevant systematic reviews in an attempt to determine the association between genotype and allelic distribution of different single-nucleotide polymorphisms (SNPs) and the development of AP, (ii) report deficiencies and gaps in knowledge in this area and (iii) present recommendations to conduct future clinical studies and systematic reviews. METHODS: A literature search was conducted using Clarivate Analytics' Web of Science, Scopus, PubMed and Cochrane Database of Systematic Reviews, from inception to October 2021, with no language restrictions, including a grey literature search. Systematic reviews with/without meta-analysis evaluating genotype and allelic distribution of different SNPs between adult patients with/ without AP were included. All other type of studies were excluded. The methodological quality was assessed using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR)-2 tool. Two independent reviewers were involved in study selection, data extraction and appraising the included reviews; disagreements were resolved by a third reviewer. RESULTS: The current study includes five systematic reviews. Three reviews performed meta-analysis. Three reviews were graded by AMSTAR 2 as 'critically low' quality, whereas the other two were graded as 'low' and 'moderate' quality. Two reviews indicated that carriers of specific genotypes and alleles of tumour necrosis factor-alpha (TNF-α) -308 G > A and interleukin 1-beta (IL-1ß) + 3954 C/T gene polymorphisms are more susceptible to an acute and persistent form of AP. However, high heterogeneity was observed. DISCUSSION: The statistical heterogeneity within included systematic reviews was a consequence of clinical and methodological diversity amongst primary studies. Although some of the included reviews suggested that carriers of specific genotype and/or allele of TNF-α -308 G > A and IL-1ß + 3954 C/T SNPs are more susceptible to AP, their conclusions should be interpreted with caution. CONCLUSIONS: No candidate genes could be identified as a definitive genetic risk or protective factor for the development and progression of AP, and further high-quality genome-wide association studies are warranted.

Role of TLR9 methylation on its active transcription in apical inflammation.

AIM: To explore the methylation pattern, its role in transcriptional regulation and potential modifiers of methylation of the TLR9 gene in chronic periapical inflammation. METHODOLOGY: In this cross-sectional study, apical lesions of endodontic origin (ALEO, n = 61) and healthy periodontal ligaments (HPL, n = 15) were included. Products from bisulfited and PCR-amplified DNA were analysed for their methylation profiles in the promoter region and at each CpG island. Additionally, TLR9 mRNA levels were quantified by qPCR and bivariate and multiple modelling were performed to better understand the influence of methylation on gene transcription. RESULTS: TLR9 mRNA levels were upregulated in ALEO compared to HPL (p < .001). TLR9 promoter CpG sites and CpG +2086 in the intragenic island 1 were demethylated in ALEO compared to HPL (p < .05). Multivariate analysis, adjusted by smoking and gender, revealed that demethylation of TLR9 promoter sites enhanced transcriptional activity, specifically demethylated CpGs at positions -736 and -683, (p = .02), which are close to CRE binding. Although ALEO reduced the global methylation of the gene promoter and intragenic-island 2 (p < .05) by -42.5 and -9.5 percentage points, respectively, age reduced the global methylation of intragenic-island 3 within the exon 2. CONCLUSIONS: Demethylations of TLR9 promoter CpG sites, along with the intragenic DNA methylation status, were involved in higher transcription in ALEO. Hence, chronic periapical inflammation and ageing modify the methylation status both in the gene promoter and in intragenic CpG islands.

CpG Single-Site Methylation Regulates TLR2 Expression in Proinflammatory PBMCs From Apical Periodontitis Individuals.

Introduction: Apical periodontitis (AP) is a common oral disease caused by the inflammatory destruction of the periapical tissues due to the infection of the root canal system of the tooth. It also contributes to systemic bacterial translocation, where peripheric mononuclear blood cells (PBMCs) can act as carriers. Toll-like receptor (TLR) 2 mediates the response to infection and activates inflammatory responses. DNA methylation can be induced by bacteria and contributes to the modulation of this response. Despite the evidence that supports the participation of PBMCs in immune-inflammatory disorders, the inflammatory profile and epigenetic regulatory mechanisms of PBMCs in AP individuals are unknown. Aim: To determine TLR2 gene methylation and inflammatory profiles of PBMCs in AP. Methods: Cross-sectional exploratory study. Otherwise, healthy individuals with AP (n=27) and controls (n=30) were included. PMBCs were isolated by a Ficoll gradient, cultured for 24 hours, and both RNA and DNA were extracted. DNA was bisulfite-treated, and specific sites at the promoter region of the TLR2 gene were amplified by qPCR using validated primers. To verify its amplification, agarose gels were performed. Then, the PCR product was sequenced. mRNA expression of TLR2 was determined by qPCR. The soluble levels of 105 inflammatory mediators were first explored with Proteome Profiler Human Cytokine Array Kit. Consequently, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, IL-6Rα, IL-1ß, and IL-12p70 levels were measured by Multiplex assay. Results: PBMCs from individuals with AP demonstrated a proinflammatory profile showing higher soluble levels of TNF-α, IL-6, and IL-1ß compared to controls (p<0.05). Higher TLR2 expression and higher global methylation pattern of the promoter region of the gene were found in AP compared to controls (p<0.05). The CpGs single-sites at positions -166 and -146 were completely methylated, while the site -102 was totally unmethylated, independently of the presence of AP. DNA methylation of CpG single-sites in positions -77 and +24 was positively associated with TLR2 expression. Conclusions: PBMCs from AP subjects show a hyperinflammatory phenotype and TLR2 upregulation in association with single CpG-sites' methylation from the TLR2 gene promoter, thereby contributing to a sustained systemic inflammatory load in individuals with periapical endodontic diseases.

Tumor Necrosis Factor Alpha -308 G/A Single-Nucleotide Polymorphism and Apical Periodontitis: An Updated Systematic Review and Meta-analysis.

INTRODUCTION: This study aimed to perform a more precise estimation of the association between tumor necrosis factor alpha (TNF-α) -308 G/A single-nucleotide polymorphism (SNP) and the risk of development of apical periodontitis (AP) and its phenotypes based on all available published studies. METHODS: The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and is registered in PROSPERO (CRD42020176190). The literature search was conducted via Clarivate Analytics Web of Science, Scopus, PubMed, Cochrane Central Register of Controlled Trials, and China National Knowledge Infrastructure databases from inception to December 2020 with no language restrictions. Two reviewers were involved independently in the study selection, data extraction, and appraising the studies that were included. The quality of the included studies was evaluated using the Strengthening the Reporting of Genetic Association and the Grading of Recommendations Assessment, Development and Evaluation system. The frequencies of the genotypes and alleles of the TNF-α (G>A 308, rs1800629) gene with 95% odds ratio were used. RESULTS: Four studies met the inclusion criteria with moderate risk of bias. This study revealed no significant association between TNF-α -308 G/A SNP and AP and the risk of AP development. Moreover, there was no significant association between genotype or allele frequency distribution and clinical manifestations (acute vs chronic) of AP. The certainty of evidence per the Grading of Recommendations Assessment, Development and Evaluation system was very low. CONCLUSIONS: Because of very low certainty of evidence, whether there is an association between TNF-α -308 G/A SNP and AP warrants further well-designed multicentric studies to adjudicate a better understanding of the role of genetic factors in the etiopathogenesis of AP.

Association between genetic polymorphisms in the promoter region of the defensin beta 1 gene and persistent apical periodontitis.

AIM: To evaluate the association between the promoter region of defensin beta 1 (DEFB1) genetic polymorphisms and persistent apical periodontitis (PAP) in Brazilian patients. METHODOLOGY: Seventy-three patients with post-treatment PAP (PAP group) and 89 patients with root filled teeth with healed and healthy periradicular tissues (healed group) were included (all teeth had apical periodontitis lesions at the beginning of the treatment). Patients who had undergone at least 1 year of follow-up after root canal treatment were recalled, and their genomic DNA was extracted from saliva. Two single nucleotide polymorphisms (SNPs) in DEFB1 at the g. -52G>A (rs1799946) and g. -20G>A (rs11362) positions were analysed using real-time polymerase chain reaction. The chi-squared test was performed, and the odds ratios were calculated using Epi Info 3.5.2. Logistic regression analysis in the codominant model, using the time of follow-up as a variable, was used to evaluate the SNP-SNP interaction. All tests were performed with an established alpha of 0.05 (P = 0.05). RESULTS: For the rs11362 polymorphism in the codominant and recessive models, patients who carried two copies of the T allele had a significantly lower risk of developing PAP (P = 0.040 and P = 0.031, respectively). For the rs1799946 polymorphism in DEFB1 in the codominant and recessive models, carrying one copy of the T allele significantly increased the risk of developing PAP (P = 0.007 and P = 0.031, respectively). In the logistic regression, both polymorphisms were associated with PAP as well as the SNP-SNP interaction (P < 0.0001). CONCLUSIONS: Polymorphisms in DEFB1 genes were associated with the development of post-treatment persistent apical periodontitis.

Investigation of Genetic Polymorphisms in BMP2, BMP4, SMAD6, and RUNX2 and Persistent Apical Periodontitis.

INTRODUCTION: This study aimed to evaluate the interplay among single-nucleotide polymorphisms (SNPs) in the encoding genes BMP2, BMP4, SMAD6, and RUNX2 in persistent apical periodontitis (PAP). METHODS: In this multicentric study, 272 patients diagnosed with pulp necrosis with apical periodontitis before root canal therapy who attended regular follow-up visits for at least 1 year were screened. Periapical radiographs and clinical aspects were evaluated, and the participants were classified as PAP (n = 110) or repaired (n = 162). Genomic DNA was used for the genotyping of the following SNPs: rs1005464 and rs235768 in bone morphogenetic protein 2 (BMP2), rs17563 in bone morphogenetic protein 4 (BMP4), rs2119261 and rs3934908 in SMAD family member 6 (SMAD6), and rs59983488 and rs1200425 in runt-related transcription factor 2 (RUNX2). The chi-square test was used to compare genotype distributions between groups. The multifactor dimensionality reduction method was applied to identify SNP-SNP interactions. The alpha for all the analysis was 5%. RESULTS: The multifactor dimensionality reduction suggested the rs235768 in BMP2 and rs59983488 in RUNX2 as the best SNP-SNP interaction model (cross-validation = 10/10, testing balanced accuracy = 0.584, P = .026) followed by rs17563 in BMP4 and rs2119261 in SMAD6 (cross validation = 10/10, testing balanced accuracy = 0.580, P = .031). In the rs235768 in BMP2 and rs59983488 in RUNX2 model, the high-risk genotype was TT + TT (odds ratio = 4.36; 95% confidence interval, 0.44-42.1). In model rs17563 in BMP4 and rs2119261 in SMAD6, GG + TT (odds ratio = 2.63; 95% confidence interval, 0.71-11.9) was the high-risk genotype. CONCLUSIONS: The interactions between rs235768 in BMP2 and rs59983488 in RUNX2 and between rs17563 in BMP4 and rs2119261 in SMAD6 are associated with PAP, suggesting that an interplay of these SNPs is involved in the higher risk of developing PAP.

MicroRNAs: emerging players in apical periodontitis

Abstract Apical periodontitis is an inflammatory disorder of periradicular tissues developed from endodontic infections. Understanding its pathophysiology and the underlying molecular mechanisms is key to the advancement of endodontics. MicroRNAs (miRNAs), a group of evolutionarily conserved small non-coding RNAs, may be phenotypically and functionally associated with the pathogenesis of apical periodontitis. Several studies have focused on the role of miRNAs in the pulp and periradicular biology, and they have demonstrated their essential functions, such as initiating odontogenic differentiation and promoting pro- or anti-inflammatory responses in pulpitis. Up to date, over 2,000 miRNAs have been discovered in humans; however, only few have been reported to associate with apical periodontitis. Therefore, identifying miRNAs involved in diseased apical tissues and conducting functional studies are important in expanding our current knowledge of pulp and periradicular biology and exploring novel therapeutic avenues. In this review, we revisit current models of apical periodontitis and miRNA biogenesis, analyze existing evidence of the involvement of miRNAs in diseased apical tissues, and discuss their diverse functions and potential values. Based on their sheer abundance, prolonged stability in biofluid, and relative ease of sampling, miRNAs may be a useful tool to be developed as diagnostic biomarkers for apical periodontitis. Furthermore, it can be used as therapeutic targets in conjunction with conventional endodontic therapies.

Association of polymorphisms in TNF-α, IL-1ß, GSTM and GSTT genes with apical periodontitis: is there a link with herpesviral infection?

AIM: To investigate the possible association between TNFα (-308 G/A) and IL-1ß (-511 C/T) single nucleotide polymorphisms (SNPs) and GSTT and GSTM deletion polymorphisms and risk of apical periodontitis (AP) development, and determine the association of different genotypes with the presence of herpesviral infection in AP. METHODOLOGY: The study included 120 periapical lesions and 200 control samples. Gene polymorphism analysis was performed using either polymerase chain reaction (PCR) or PCR/ restriction fragment length polymorphism (RFLP). Relative gene expression of TNF-α and IL-1ß was analysed using reverse transcriptase - real-time PCR. The presence of Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) was assessed by nested PCR. Chi-square and Fisher's exact tests and logistic regression analyses were done for polymorphisms, whilst Mann-Whitney U-test was performed for the expression analysis. The expected frequency of variants was analysed by the Hardy-Weinberg equilibrium test. RESULTS: TNF-α (-308 G/A) SNP increased AP susceptibility for heterozygous (odds ratio (OR) = 1.72, 95% confidence interval (CI) = 1.06-2.80, P = 0.027) and homozygous (OR = 8.55, 95% CI = 1.77-41.36, P < 0.001) carriers of the variant A allele. On the other hand, IL-1ß (-511 C/T) polymorphism exerted a protective effect both in heterozygotes (OR = 0.540, 95% CI = 0.332-0.880, P = 0.013) and homozygotes (OR = 0.114, 95% CI = 0.026-0.501, P < 0.001). In addition, GSTM1 and GSTT1 null genotypes separately, as well as concomitantly, were associated with an increased risk for AP development (P < 0.001). The null GSTT1 genotype increased approximately twice the risk of Epstein-Barr infection (EBV) in AP (OR = 2.17, 95% CI = 1-4.71, P = 0.048), whilst TNF-α SNP decreased it, both in heterozygotes (OR = 0.20, 95% CI = 0.08-0.48, P < 0.001) and AA homozygotes (OR = 0.07, 95% CI = 0.01-0.37, P = 0.001). CONCLUSIONS: GSTM and GSTT deletion polymorphisms, as well as TNFα (-308 G/A) SNP, are associated with increased risk, whereas IL-1ß (-511 C/T) polymorphism decreases the risk of AP development. GSTT and TNFα polymorphisms also appear to modulate the risk of EBV infection in Serbian patients with AP.

Effects of 5-lipoxygenase gene disruption on inflammation, osteoclastogenesis and bone resorption in polymicrobial apical periodontitis.

OBJECTIVES: To investigate the regulation of inflammatory and osteoclastogenic signaling by 5-lipoxygenase (5-LO) in apical periodontitis induced by oral contamination of dental root canals in mice. DESIGN: Apical periodontitis was induced in 5-lipoxygenase enzyme knockout (129-Alox5tm1Fun) and 129 wild-type mice (n = 96) by exposure of the dental root canal to the oral cavity. After 7, 14, 21, and 28 days, the animals were euthanized and the tissues removed (n = 12 teeth per period) for histopathological and histometric analyses (hematoxylin and eosin [HE]), evaluation of osteoclastogenic activity (tartrate-resistant acid phosphatase enzyme [TRAP]), and determination of inflammatory and osteoclastogenic signaling (qRT-PCR). RESULTS: Oral contamination of dental root canals induced recruitment of neutrophils and osteoclasts to the periodontal ligament, resulting in bone resorption. Absence of 5-LO did not impair neutrophil recruitment while osteoclastic formation was increased. Nonetheless, early bone resorption progressed similarly to lesions in wild-type animals. Interestingly, in the absence of 5-LO, the synthesis of mRNAs for cytokines, chemokines, and their receptors was significantly reduced while that of regulators of osteoclastogenesis (RANK, RANKL, and OPG) was increased in comparison with the corresponding levels in wild-type animals. CONCLUSIONS: The 5-LO pathway plays a role in the stimulation of inflammatory mediator synthesis and inhibition of osteoclastogenesis in apical periodontitis in mice. However, the paradoxical inflammatory-osteoclastogenic signaling did not impair inflammatory cell recruitment and bone resorption during early development of the disease.

Influence of genetic regulatory effects modified by environmental immune activation on periapical disease.

The objective of this study was to compare the periradicular responses in endodontic infections among members of two populations: an urban Brazilian population and a non-mixed indigenous population. Samples were collected immediately and 7 days after the cleaning and shaping procedures (after reducing the intracanal microbial load) in an attempt to characterize the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-9, interferon (IFN)-γ, IL-17, IL-10, and the chemokines CXCR4, CCL2/monocyte chemotactic protein (MCP)-1, and CCR6. The endogenous cytokine and chemokine expression levels were analyzed using real-time PCR. Only the urban population showed a significant increase in TNF-α, CCL2/MCP-1, CXCR4, and CCR6 expression following the cleaning and shaping of the root canal system. The IFN-γ levels were increased at the 2nd collection (p < 0.05) in the indigenous population. In turn, a significant increase in IL-10 and IL-17 expression (p < 0.05) was observed after the cleaning and shaping procedures (2nd collection) in both populations. No significant differences in the IL-1ß, IL-9, and CCL4 expression levels were observed between the 1st and 2nd collections in both populations. The results demonstrate a cytokine and chemokine expression profile that is specific to each analyzed population. However, immune modulation mediated by IL-10 began on the 7th day after the beginning of the endodontic treatment in both populations.

Genetic Polymorphisms in RANK and RANKL are Associated with Persistent Apical Periodontitis.

INTRODUCTION: The outcome of root canal treatment has been reported as intimately related to the host response. Genetic polymorphisms might be associated with apical periodontitis repair. The aim of this study was to evaluate the association between receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) genetic polymorphisms with persistent apical periodontitis (PAP) in Brazilian subjects. METHODS: Subjects with at least 1 year of follow-up after nonsurgical root canal therapy were recalled. Sixty-four subjects with signs/symptoms of PAP and 86 subjects with root canal-treated teeth exhibiting healthy periradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for RANK (rs3826620), RANKL (rs9594738), and OPG (rs2073618) genotyping by real-time exact tests, and odds ratio were implemented using Epi Info 3.5.2 (Centers for Disease Control and Prevention, Atlanta, GA). A logistic regression analysis was also performed using the time of follow-up as the covariate. All tests were performed with an established alpha of 0.05 (P = .05). RESULTS: An association between allele distribution and the polymorphism in RANK was observed. Subjects who carry the T allele had a lower risk of having PAP (P < .05). In RANKL polymorphism, the genotype distribution was statistically significant different between the PAP and healed groups (P = .05). The time of follow-up was associated with PAP (P < .05). In the logistic regression analysis using time as a covariant, RANK (P < .05) and RANKL (P < .05) were associated with PAP. The polymorphism rs2073618 in OPG was not associated with PAP (P > .05). CONCLUSIONS: These findings suggest that polymorphisms in RANK and RANKL genes are associated with PAP.

Investigating Potential Correlations between Endodontic Pathology and Cardiovascular Diseases Using Epidemiological and Genetic Approaches.

INTRODUCTION: Apical periodontitis (AP) and cardiovascular diseases (CVDs) are chronic conditions triggered by an inflammatory process and sharing similar pathogeneses and molecular players. Previous studies have suggested that AP may perpetuate a systemic inflammation state and, in turn, contribute to CVD. In this study, we investigated the potential association between endodontic pathology and CVD using epidemiological and genetic approaches. METHODS: Epidemiologic analysis was performed by querying the medical and dental records of >2 million patients. We retrieved information on positive/negative history for endodontic pathologies and CVDs using diagnostic and treatment codes from a dental school-based and a hospital-based patient electronic health record system. A case-control genetic association study was also performed; 10 single nucleotide polymorphisms in genes identified as strongly associated with CVDs were genotyped in 195 cases with AP and 189 control individuals without AP. Data analyses were performed using the chi-square and Fisher exact tests. P ≤.05 indicates significant difference between groups. RESULTS: Significant associations were found between the presence of endodontic pathology and a history of hypertension, myocardial infarction, cerebrovascular accident, pacemaker, congestive heart failure, heart block, deep vein thrombosis, and cardiac surgery (0.0001 ≤ P ≤ .008). A modest association was found for heart murmur and atrial fibrillation (P = .04). A trend toward positive association (P = .05) was also found between AP and a single nucleotide polymorphism in KCNK3, a gene known to be involved in increased susceptibility to hypertension. CONCLUSIONS: Significant associations were found between endodontic pathology and various CVDs and CVD-related risk factors, particularly hypertension. A trend toward a positive association was also found between AP and KCNK3, suggesting that common genetic variations may underlie different diseases. Additional studies with larger sample sizes have the potential to elucidate common mechanisms underlying AP and CVD.

Notch Signaling Pathway in Apical Periodontitis: Correlation with Bone Resorption Regulators and Proinflammatory Cytokines.

INTRODUCTION: The exact mechanisms of periapical bone resorption have not been fully elucidated. This study aimed to analyze the expression of Notch signaling molecules (Notch2, Jagged1, and Hey1) and proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin [IL]-1ß, and IL-6) in human apical periodontitis lesions with different receptor activator of nuclear factor kappa B ligand (RANKL)/osteoprotegerin (OPG) ratios and determine their potential correlation. METHODS: The study group consisted of 50 periapical lesions collected in conjunction with apicoectomy. The relative gene expression of the investigated molecules (Notch2, Jagged1, Hey1, RANKL, OPG, TNF-α, IL-1ß, and IL-6) in all tissue samples was analyzed using reverse transcriptase real-time polymerase chain reaction. The Student t test, Mann-Whitney U test, and Spearman correlation were used for statistical analysis. RESULTS: Based on the RANKL/OPG ratio, periapical lesions were either RANKL predominant (RANKL > OPG, n = 33) or OPG predominant (RANKL < OPG, n = 17). Symptomatic lesions occurred more frequently in RANKL-predominant compared with OPG-predominant lesions (24 vs 7, P = .029). Notch2, Jagged1, Hey1, and TNF-α were significantly overexpressed in lesions with predominant RANKL compared with lesions with predominant OPG (P = .001, P = .001, P = .027, and P = .016, respectively). Significant correlations were observed between the investigated genes in periapical lesions. CONCLUSIONS: Notch signaling appeared to be activated in periapical inflammation. An increase in Notch2, Jagged1, Hey1, and TNF-α expression in RANKL-predominant periapical lesions corroborates their joined involvement in extensive periapical bone resorption.

Influence Of Genetic Polymorphisms In Genes Of Bone Remodeling And Angiogenesis Process In The Apical Periodontitis.

Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher's exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.

Influence of genetic polymorphisms in genes of bone remodeling and angiogenesis process in the apical periodontitis

Abstract Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher's exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.

Resumo A periodontite apical persistente (PAP) é uma condição que envolve uma resposta inflamatória e imunológica causada principalmente por infecções polimicrobianas de origem anaeróbia no sistema de canais radiculares, tornando o resultado e o acompanhamento do tratamento do canal radicular intimamente relacionados à resposta do hospedeiro. O reparo da periodontite apical pode estar associado a polimorfismos genéticos. Este estudo teve como objetivo avaliar a associação entre os polimorfismos genéticos do HIF1A (rs2301113 e rs2057482) com a PAP em pacientes brasileiros. Indivíduos com pelo menos 1 ano de acompanhamento após o tratamento do canal radicular (TCR) foram agendados para consulta de acompanhamento. Sessenta e quatro indivíduos com sinais/sintomas de PAP e 84 indivíduos com dentes tratados endodonticamente e tecidos perirradiculares saudáveis (cicatrizados) foram incluídos no presente estudo. O DNA genômico foi extraído da saliva e utilizado para a genotipagem do HIF1A por PCR em tempo real. O genótipo e as frequências alélicas foram comparados por teste c2 ou exato de Fisher e odds-ratio foi implementado por meio do software Epi Info 3.5.2. Todos os testes realizados foram estabelecidos com a=0,05. Não houve associação entre alelo e distribuição genotípica para polimorfismos do HIF1A e PAP (p> 0,05). Os polimorfismos genéticos em HIF1A não foram associados à periodontite apical persistente.