Oral Phenotype and Salivary Microbiome of Individuals With Papillon-Lefèvre Syndrome.

Papillon-Lefèvre syndrome (PLS) is an autosomal recessive rare disease, main characteristics of which include palmoplantar hyperkeratosis and premature edentulism due to advanced periodontitis (formerly aggressive periodontitis). This study aimed to characterize the oral phenotype, including salivary parameters, and the salivary microbiome of three PLS sisters, comparatively. Two sisters were toothless (PLSTL1 and PLSTL2), and one sister had most of the teeth in the oral cavity (PLST). Total DNA was extracted from the unstimulated saliva, and the amplicon sequencing of the 16S rRNA gene fragment was performed in an Ion PGM platform. The amplicon sequence variants (ASVs) were obtained using the DADA2 pipeline, and the taxonomy was assigned using the SILVA v.138. The main phenotypic characteristics of PLS were bone loss and premature loss of primary and permanent dentition. The PLST sister presented advanced periodontitis with gingival bleeding and suppuration, corresponding to the advanced periodontitis as a manifestation of systemic disease, stage IV, grade C. All three PLS sisters presented hyposalivation as a possible secondary outcome of the syndrome. Interestingly, PLST salivary microbiota was dominated by the uncultured bacteria Bacterioidales (F0058), Fusobacterium, Treponema, and Sulfophobococcus (Archaea domain). Streptococcus, Haemophilus, and Caldivirga (Archaea) dominated the microbiome of the PLSTL1 sister, while the PLSTL2 had higher abundances of Lactobacillus and Porphyromonas. This study was the first to show a high abundance of organisms belonging to the Archaea domain comprising a core microbiome in human saliva. In conclusion, a PLST individual does have a microbiota different from that of the periodontitis' aggressiveness previously recognized. Due to an ineffective cathepsin C, the impairment of neutrophils probably provided a favorable environment for the PLS microbiome. The interactions of Bacteroidales F0058, Caldivirga, and Sulfophobococcus with the microbial consortium of PLS deserves future investigation. Traditional periodontal therapy is not efficient in PLS patients. Unraveling the PLS microbiome is essential in searching for appropriate treatment and avoiding early tooth loss.

Association Between Tumor Necrosis Factor-α (G-308A) Polymorphism and Chronic Periodontitis, Aggressive Periodontitis, and Peri-implantitis: A Meta-analysis.

OBJECTIVE: Chronic periodontitis (CP), aggressive periodontitis (AP), and peri-implantitis (PI) are chronic inflammatory diseases. Tumor necrosis factor-α (TNF-a) is an effective immune inflammatory mediator. Several studies have been conducted to explore the association between the TNF-α (G-308A) polymorphism and susceptibility to CP, AP, and PI. Our objective was to examine whether the TNF-α (G-308A) polymorphism is related to these diseases. METHODS: We conducted a meta-analysis to investigate the association between the TNF-α (G-308A) polymorphism and CP, AP, and PI. The PubMed, Embase, CNKI, and Web of Science electronic databases were searched for studies published from inception to August 11, 2020; the reference lists of included studies were also searched. The included studies were assessed in the following genetic models: dominant model, recessive model, allelic model, heterozygous model, and homozygous model. RESULTS: Forty articles (50 comparisons) with 2243 CP, 824 AP, 615 PI, 795 healthy peri-implant, and 3575 healthy controls were considered for the TNF-α (G-308A) polymorphism in this meta-analysis. Variant A of TNF-α (G-308A) was associated with increased AP risk in the general population, especially in Asians, and this polymorphism was significantly associated with elevated risk of CP in Asians and Caucasians. There was no association between the A allele and PI risk. None of the contrasts of the genetic model yielded a significant finding in Latin Americans. Different genotyping methods may affect the association between the TNF-α (G-308A) polymorphism and these diseases. CONCLUSION: These findings supported that variant A of the TNF-α (G-308A) polymorphism may contribute to CP and AP susceptibility, particularly in Asians and Caucasians. More efforts and further studies with larger sample sizes will be required to validate the risk of CP, AP, and PI.

1α,25-dihydroxyvitamin D3 promotes early osteogenic differentiation of PDLSCs and a 12-year follow-up case of early-onset vitamin D deficiency periodontitis.

Periodontitis is a chronic periodontal disease that contributes to tooth loss. In recent years, many animal studies have reported that vitamin D (VitD) deficiency results in chronic periodontitis. However, no studies have reported cases of early-onset periodontitis with VitD deficiency. This study reports a 5-year-old male patient with early-onset periodontitis, VitD deficiency and VitD receptor (VDR) mutation. The patient was treated with VitD and calcium, and received systematic periodontal treatment. During the 12-year treatment, the periodontal conditions of this patient were stable. Our in vitro study found that VitD could promote the expression of alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), bone morphogenetic protein 2 (BMP2), bone gamma-carboxyglutamate protein (BGLAP), and VDR in the early osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Meanwhile, VitD could downregulate mRNA expression levels of Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-1ß (IL-1ß) and protein levels of IL-6 in the tumor necrosis factor-α (TNF-α) -induced inflammation of PDLSCs. Therefore, sufficient VitD supply can be a potential treatment for VitD deficiency induced early-onset periodontitis.

Application of weighted gene co-expression network analysis to reveal key modules and hub genes in generalized aggressive periodontitis.

OBJECTIVE: The aim of this study was to construct a gene co-expression network to identify key modules and genes in people with generalized aggressive periodontitis. METHODS: We used database GSE79705 to construct a co-expression network by weighted gene co-expression network analysis (WGCNA). In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted. RESULTS: A total of 51 co-expression modules were conducted, darkseagreen1 and blue1 modules were the most significantly related to generalized aggressive periodontitis. Genes in the darkseagreen1 module enriched in affecting cellular response to tumor necrosis factor and vascular endothelial growth factor production, and the blue1 module enriched in the regulation of ion transport, proteinaceous extracellular matrix and neuropeptide binding. Besides, we found that 4 hub genes (SNRPG, MRPL22, MRPS18C and CEP290) played an important role in the occurrence of generalized aggressive periodontitis. CONCLUSION: Through this study, we identified two modules and four hub genes associated with generalized aggressive periodontitis. Besides, 4 hub genes (SNRPG, MRPL22, MRPS18C and CEP290) can be expected to trigger new therapeutic drug development for generalized aggressive periodontitis.

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 IL­10-1087 A/G (rs1800896) and specific IL-10 haplotypes were associated with the development of the disease (P < 0.05, Pcorr > 0.05). Four bacterial species occurred more frequently in AgP than in controls (P < 0.01, Pcorr < 0.05). Elevated IL-10 levels were found in AgP patients, carriers of IL­10-1087GG genotype, and PBMCs stimulated by periodontal bacteria (P < 0.05, Pcorr > 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.

Impact of history of periodontitis on gene expression of bone-related factors in young patients.

Although dental implants and bone regenerative procedures are important approaches for the reestablishment of esthetics and function in young patients with a history of generalized aggressive periodontitis (GAP), no predictable outcomes have been reported, and the host osteo-immunoinflammatory response may play a relevant role in this context. In view of the lack of molecular investigations into the bone tissue condition of young patients with periodontitis, the aim of this study was to evaluate the gene expression of bone-related factors in this population. Bone biopsies were obtained from the posterior mandible in 16 individuals previously diagnosed with GAP and on periodontal support therapy and from 17 periodontally healthy (PH) patients. The gene expression of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß, receptor activator of the NF-κB ligand (RANKL), osteoprotegerin (OPG), osteocalcin (OC), bone sialoprotein (BSP), and type I collagen (COL-I), important biomarkers of bone turnover, was evaluated by qRT-PCR. Lower TGF-ß and OPG mRNA levels were observed in GAP patients compared to PH individuals (p ≤ 0.05). There were no between-group differences in levels of TNF-α, BSP, RANKL, OC, or COL-I mRNA (p>0.05). In young adults, a history of periodontal disease can negatively modulate the gene expression of important bone-related factors in alveolar bone tissue. These molecular outcomes may contribute to the future development of therapeutic approaches to benefit bone healing in young patients with history of periodontitis via modulation of osteo-immuno-inflammatory biomarkers.

Impact of history of periodontitis on gene expression of bone-related factors in young patients

Abstract Although dental implants and bone regenerative procedures are important approaches for the reestablishment of esthetics and function in young patients with a history of generalized aggressive periodontitis (GAP), no predictable outcomes have been reported, and the host osteo-immunoinflammatory response may play a relevant role in this context. In view of the lack of molecular investigations into the bone tissue condition of young patients with periodontitis, the aim of this study was to evaluate the gene expression of bone-related factors in this population. Bone biopsies were obtained from the posterior mandible in 16 individuals previously diagnosed with GAP and on periodontal support therapy and from 17 periodontally healthy (PH) patients. The gene expression of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, receptor activator of the NF-κB ligand (RANKL), osteoprotegerin (OPG), osteocalcin (OC), bone sialoprotein (BSP), and type I collagen (COL-I), important biomarkers of bone turnover, was evaluated by qRT-PCR. Lower TGF-β and OPG mRNA levels were observed in GAP patients compared to PH individuals (p ≤ 0.05). There were no between-group differences in levels of TNF-α, BSP, RANKL, OC, or COL-I mRNA (p>0.05). In young adults, a history of periodontal disease can negatively modulate the gene expression of important bone-related factors in alveolar bone tissue. These molecular outcomes may contribute to the future development of therapeutic approaches to benefit bone healing in young patients with history of periodontitis via modulation of osteo-immuno-inflammatory biomarkers.

Association between the IL-10 rs1800872 polymorphisms and periodontitis susceptibility: A meta-analysis.

BACKGROUND: Periodontitis is a common disease with an unclear pathological mechanism. No precise consensus has been reached to evaluate the association between the IL-10 rs1800872 (- 592, -590, -597 C>A) polymorphism and periodontal disease. Thus, we performed this meta-analysis to collect more evidence-based information. METHODS: Four online databases, PubMed, Embase, Web of Science, and China Biology Medicine disc (CBM), were searched in August 2018. An odds ratio (OR) with a 95% confidence interval (CI) was applied to evaluate the association of the rs1800872 with periodontitis susceptibility. RESULTS: Twenty three case-control studies with 2714 patients and 2373 healthy controls were evaluated. The overall analyses verified that the IL-10 rs1800872 polymorphism was significantly associated with an increased risk of periodontitis in the allelic model, homozygote model, dominant model, and recessive model (A vs C: OR = 1.28, 95%CI = 1.11-1.49, P = .00, I = 56.87%; AA vs CC: OR = 2.06, 95%CI = 1.32-3.23, P = .00, I = 73.3%; AA + AC vs CC: OR = 1.42, 95%CI = 1.03-1.96, P = .03, I = 76.2%; AA vs AC + CC: OR = 1.78, 95%CI = 1.26-2.56, P = .00, I = 76.7%). Moreover, the subgroup analysis based on ethnicity, periodontitis type, and smoking status showed significant differences. CONCLUSIONS: The results of our meta-analysis demonstrate that rs1800872 is associated with periodontitis susceptibility in Caucasians and Asians. Moreover, A allele, AA genotype, CC genotype may be closely associated with chronic periodontitis (CP), while A allele, AA genotype may be closely associated with aggressive periodontitis (AgP).

Smoking Modifies the Genetic Risk for Early-Onset Periodontitis.

Periodontitis has low-prevalence, highly severe disease manifestations with an early onset and rapid progression. The diagnosis is based on severe destruction of the alveolar bone in adolescents and young adults. Genetic susceptibility variants and smoking are well-established risk factors, but their interactions in modifying disease susceptibility have not been studied. We aimed to identify genetic risk variants of early-onset periodontitis that unmask their effects on tobacco smoke exposure. To this end, we analyzed 79,780,573 common variants in 741 northwest Europeans diagnosed to have >30% bone loss at >2 teeth before 35 y of age, using imputed genotypes of the OmniExpress BeadChip. Never versus ever smokers were compared in a logistic regression analysis via a case-only approach. To explore the effect of tobacco smoke on the expression of the G×S-associated genes, cultures of primary gingival fibroblasts (n = 9) were exposed to cigarette smoke extract, and transcripts were quantified by reverse transcription polymerase chain reaction. We identified 16 loci for which our analysis suggested an association with G×S increased disease risk (P < 5 × 10-5). Nine loci had previously been reported to be associated with spirometric measures of pulmonary function by an earlier G×S genome-wide association study. Genome-wide significant cis expression quantitative trait loci were reported for G×S-associated single-nucleotide polymorphisms at ST8SIA1 and SOST, indicating a causal role of these genes in tobacco-related etiopathology. Notably, SOST is a negative regulator of bone growth, and ST8SIA1 has a role in tissue remodeling. Cigarette smoke extract significantly altered the expression of 2 associated genes: SSH1 (P = 5 × 10-07), which is required for NF-κB activation and innate immune responses to bacterial invasion, and ST8SIA1 (P = 0.0048). We conclude that the genetic predisposition to early-onset periodontitis is in part triggered by smoking and that tobacco smoke directly affects the expression of genes involved in bone homeostasis, tissue repair, and immune response.

Exome sequencing identifies a novel missense variant in CTSC causing nonsyndromic aggressive periodontitis.

Cathepsin C (CatC) is a cysteine protease involved in a variety of immune and inflammatory pathways such as activation of cytotoxicity of various immune cells. Homozygous or compound heterozygous variants in the CatC coding gene CTSC cause different conditions that have in common severe periodontitis. Periodontitis may occur as part of Papillon-Lefèvre syndrome (PLS; OMIM#245000) or Haim-Munk syndrome (HMS; OMIM#245010), or may present as an isolated finding named aggressive periodontitis (AP1; OMIM#170650). AP1 generally affects young children and results in destruction of the periodontal support of the primary dentition. In the present study we report exome sequencing of a three generation consanguineous Turkish family with a recessive form of early-onset AP1. We identified a novel homozygous missense variant in exon 2 of CTSC (NM_148170, c.G302C, p.Trp101Ser) predicted to disrupt protein structure and to be disease causing. This is the first described CTSC variant specific to the nonsyndromic AP1 form. Given the broad phenotypic spectrum associated with CTSC variants, reporting this novel variant gives new insights on genotype/phenotype correlations and might improve diagnosis of patients with early-onset AP1.

Assessment of microRNA-146a in generalized aggressive periodontitis and its association with disease severity.

BACKGROUND AND OBJECTIVE: MicroRNA-146a (miR-146a) is a small noncoding RNA that plays a critical role in the negative regulation of the innate immune response, and the dysregulation of miR-146a has been associated with several inflammatory disorders. In generalized aggressive periodontitis (GAgP) the degree of clinical inflammation appears to be similar to that of chronic periodontitis, and, in this situation, age of onset and family history are important additional criteria for diagnosis. This study was performed to evaluate the level of miR-146a expressed in gingival tissues of patients with GAgP and its association with disease severity. MATERIAL AND METHODS: Gingival samples from 18 patients with GAgP and 10 healthy subjects were collected and the level of miR-146a and its targets, including necrosis factor-alpha, interleukin-1beta, and interleukin-6, were assessed using real-time PCR. Clinical parameters, including probing depth and clinical attachment loss, were measured and their correlations with the level of miR-146a were determined. RESULTS: Our results demonstrated an elevation in the level of miR-146a expressed in patients with GAgP compared with healthy controls (P < .001), which was directly associated with disease severity (P < .05). Overexpression of miR-146a was accompanied by a reduction in the levels of pro-inflammatory cytokines. CONCLUSIONS: Our findings suggest that there is an association between miR-146a and GAgP and imply that miR-146a may serve as an indicator of periodontal disease severity. However, further studies and additional information are required to confirm this relationship and the precise role of miR-146a in the development and/or progression of periodontitis.

Functional Polymorphisms of CTLA4 Associated with Aggressive Periodontitis in the Chinese Han Population.

BACKGROUND/AIMS: CTLA4 has been identified functioning as a protein receptor which functions as an immune checkpoint, downregulating the immune system. Susceptibility to aggressive periodontitis (AgP) is influenced by gene polymorphisms related to the immune response. In this study, we focused on SNPs in the 3'-UTR of CTLA4 among Chinese AgP patients, and investigated any further relationships between the SNPs and miRNAs. METHODS: This case-control study included 120 AgP patients and 150 healthy controls. Genotyping was used to detect allele distribution. Cell transfection and the dual luciferase reporter assay were performed to investigate the potential functions of SNPs located in the 3'UTR of CTLA4. RESULTS: The data show that patients with a history of smoking were more susceptible compared to controls, exhibiting deeper probing depth, greater attachment loss and more sites of bleeding on probing. The results of genotyping analysis revealed that individuals with the GA and AA genotypes, and with the A carrier had a decreased risk (P = 0.015, P = 0.03). Furthermore, patients with the G allele might be regulated by miR-105, which caused a down-regulation of CTLA4. The carriers of the GG genotype exhibited the worst results of attachment loss and bleeding on probing. CONCLUSION: These findings show that rs56102377 in the 3'-UTR of CTLA4 may act as a protective factor by disrupting the regulatory role of miR-105 in CTLA4 expression. Thus, our study highlighted a potential role of these polymorphisms as genetic susceptibility biomarkers of periodontitis in Chinese Han populations.

[Expression profile of long non-coding RNA in gingival tissues from the patients with aggressive periodontitis].

Objective: To detect and analyze the differential expression profile of long non-coding RNA (lncRNA) in aggressive periodontitis (AgP) and healthy gingival tissues, in order to explore the role of lncRNA in AgP. Methods: After the informed consents were obtained, gingival tissues from AgP patients (n=40) and healthy volunteers (n=40) were collected in Department of Periodontology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine (from Mar. 2012 to Aug. 2012) and Department of Periodontology, Hospital of Stomatology, Tianjin Medical University (from Oct. 2016 to Apr. 2017). The differential expression of lncRNA of tissues from AgP patients (n=20) and healthy volunteers (n=20) were examined via microarray assay. Bioinformatics was applied to analyze the expression data of lncRNA and correlative mRNA. Two lncRNAs (lncRNA-TNFRSF13C and lncRNA-API5) were chosen to verify the microarray results by using real time quantitative polymerase chain reaction (PCR) in the other gingival tissues. Results: Compared with the result of healthy gingival tissues, totally 8 632 lncRNAs were differentially expressed in tissues from AgP patients. From these data, 1 986 lncRNAs were significantly upregulated while 6 646 lncRNAs were downregulated, amongst which 48 lncRNAs were upregulated (>10 times) (P<0.05), 14 lncRNAs were downregulated (>10 times) (P<0.05). Furthermore, totally 5 519 correlative mRNAs were differentially expressed, amongst which 1 676 mRNAs were upregulated (≥2 times, P<0.05) and 3 843 mRNAs were downregulated≤0.5 (P<0.05). The selected lncRNA-TNFRSF13C and lncRNA-API5 were up-regulated in AgP (P<0.05), which confirmed the results of microarray. From bioinformatics, differential expression lncRNAs were in association with many signal pathways including toll-like receptor signaling pathway, cell cycle and apoptosis pathway, and tumor necrosis factor receptor superfamily pathway. Conclusions: LncRNA may be involved in the pathogenesis of AgP through various pathways, which need to be further explored.

Aggregatibacter (Actinobacillus) actimycetemcomitans leukotoxin and human periodontitis - A historic review with emphasis on JP2.

Aggregatibacter (Actinobacillus) actimycetemcomitans (Aa) is a gram-negative bacterium that colonizes the human oral cavity and is causative agent for localized aggressive (juvenile) periodontitis (AgP). In the middle of 1990s, a specific JP2 clone of belonging to the cluster of serotype b strains of Aa with highly leukotoxicity (leukotoxin, LtxA) able to kill human immune cells was isolated. JP2 clone of Aa was strongly associated with in particularly in rapidly progressing forms of aggressive periodontitis. The JP2 clone of Aa is transmitted through close contacts. Therefore, AgP patients need intense monitoring of their periodontal status as the risk for developing severely progressing periodontitis lesions are relatively high. Furthermore, timely periodontal treatment, including periodontal surgery supplemented by the use of antibiotics, is warranted. More importantly, periodontal attachment loss should be prevented by early detection of the JP2 clone of Aa by microbial diagnosis testing and/or preventive means.

Analysis of IL-6, IL-10 and NF-κB Gene Polymorphisms in Aggressive and Chronic Periodontitis.

OBJECTIVE: Pro-inflammatory cytokines, interleukin-6 (IL-6), demonstrated to be suppressed by interleukin-10 (IL-10) are known to be regulated by the transcription factor nuclear factor-κB(NF-κB). The aim of this study was to ascertain the association between genetic polymorphism of these genes (IL-6(-174), IL-10(-597) and NF-κB1-94ins/del)) and chronic/aggressive periodontitis. METHODS: Forty-five patients with chronic periodontitis (CP), 58 patients with aggressive periodontitis (AP) and 38 periodontally healthy subjects were included in this study. Genomic DNA was isolated from whole blood samples. The NF-κB, IL-6, and IL-10 polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: Among subjects for the ins/ins genotypes of NF-κB1 gene, the AA genotypes of IL-10 presented a higher frequency in chronic periodontitis group than in healthy controls (p=0.023). A statistically significant difference in genotyping frequencies between AP group and healthy controls was observed for the IL-6 gene. The AA genotype of IL-10 was overrepresented in CP and AP groups compared to healthy controls (OR=9.93, 95% CI: 2.11-46.7, OR=5.7, 95% CI: 1.22-26.89, respectively). CONCLUSIONS: Within the limits of this study, it can be concluded that the IL-10 (-597) AA genotype is associated with susceptibility to chronic/aggressive periodontitis and IL-6 (-174) GG genotypes and G allele seems to be associated with aggressive periodontitis. Clinical relevance: The results of the current study indicate that IL-6 and IL-10 genotypes seem to be associated with aggressive periodontitis. Also, the AA genotypes of IL-10 presented a higher frequency in chronic periodontitis subjects with carrying NF-κB1 ins/ins genotypes.

A haplotype block downstream of plasminogen is associated with chronic and aggressive periodontitis.

AIM: The intronic variant rs4252120 in the plasminogen gene (PLG) is known to be associated with aggressive periodontitis (AgP) and atherosclerosis. Here, we examined the chromosomal region spanning PLG for associations with both chronic periodontitis (CP) and AgP. MATERIALS AND METHODS: The association of PLG candidate rs4252120 was tested in a German case-control sample of 1,419 CP cases using the genotyping assay hCV11225947 and 4,562 controls, genotyped with HumanOmni BeadChips. The German and Dutch sample of AgP cases (N = 851) and controls (N = 6,836) were genotyped with HumanOmni BeadChips. The North American CP sample (N = 2,681 cases, 1,823 controls) was previously genotyped on the Genome-Wide Human SNP Array 6.0. Genotypes were imputed (software Impute v2), and association tests were performed using an additive genetic model adjusting for sex and smoking. RESULTS: Rs4252120 was not associated with CP. However, a haplotype block downstream of PLG and not in linkage disequilibrium with rs4252120 (r2  = .08) was associated with both AgP (rs1247559; p = .002, odds ratio [OR] = 1.33) and CP (p = .02, OR = 1.15). That locus was also significantly associated with PLG expression in osteoblasts (p = 6.9 × 10-5 ). CONCLUSIONS: Our findings support a role of genetic variants in PLG in the aetiology of periodontitis.

IL-6 and IL-10 gene polymorphisms in patients with aggressive periodontitis: effects on GCF, serum and clinic parameters.

Genetic variations observed in cytokines affect periodontitis susceptibility. The aim of this study was to investigate interleukin(IL)-6(-174) and IL-10(-597) gene polymorphisms in generalized aggressive periodontitis (GAgP) patients. Also, we aimed to evaluate the effects of IL-6 and IL-10 gene polymorphisms on the clinical outcomes of non-surgical periodontal therapy and cytokine levels in gingival crevicular fluid(GCF) and serum. Fifty-three patients with GAgP and 50 periodontally healthy individuals were included in this study. Clinical parameters, GCF and blood samples were collected at baseline and at 6-week. Non-surgical periodontal therapy was performed in patients with GAgP. Gene analysis were determined by PCR-RFLP(polymerase chain reaction-restriction fragment length polymorphism) and cytokine levels were determined by enzyme-linked immunosorbent assay(ELISA).GAgP patients showed significant improvement on clinical parameters after periodontal therapy(p<0.05). In the GAgP group, IL-6 GG genotype and G allele frequency were higher than in the control group. GCF IL-6 level was also significantly lower at 6-week in the GAgP group. Higher GCF IL-10 levelswere observed in patients carrying the IL-6 GG genotype than in those carrying the GC+CC genotype at baseline. In conclusion, IL-6(-174) and IL-10(-597) gene polymorphisms were found to be associated with GAgP and genotype distribution did not affect the outcome of non-surgical periodontal therapy, while patients with IL-6(-174) GG genotype had higher levels of GCF IL-10 levels.

Association of genetic polymorphisms with resistance and susceptibility phenotypes to chronic inflammatory osteolytic periapical and periodontal lesions / Associação de polimorfismos genéticos com os fenótipos de resistência e susceptibilidade à lesões osteolíticas periodontais e periapicais

Chronic periodontitis and apical periodontitis are infectious diseases characterized by the inflammatory destruction of teeth-supporting tissues. The clinical presentation of these diseases is the result of the interaction between the infecting microorganisms and the host's defense mechanisms, constituting the host/pathogen barrier. Genetic variations are associated with differential susceptibility profiles, modulating simultaneously the patterns of infection and immune response. Therefore, we investigated the association of selected genetic variations with phenotypes of resistance or susceptibility to periodontal and periapical inflammatory bone resorption, as well as with changes in the sub gingival microbial profile and host's response biomarkers. The polymorphism rs4794067 (gene TBX21) proved significantly associated with increased risk to suffer periodontitis. Polymorphic allele-carriers demonstrated increased expression of T-bet. IFN-γ expression and bacterial load proved unaltered by genotype differences. The mutation rs333 (a.k.a. CCR5Δ32, in gene CCR5) demonstrated a protective effect against chronic periodontitis. Heterozygous subjects exhibited decreased TNF-α expression. The genetic mutation was unrelated to changes in the bacterial load of putative periodontal pathogens. The polymorphisms rs2521634 (gene NPY), rs10010758 (gene TBC1D), rs6667202 (gene IL10), and rs10043775 (gene TBXO38) proved associated with significant changes in the composition of the subgingival biofilm in chronic periodontitis patients. For apical periodontitis we employed an unbiased biomarker screening strategy based in 2D diferential electrophoresis in tandem with mass spectrometry. Among the biomarkers that proved significantly modulated, we discover a substantial upregulation of HSP27 and SERPINB1. Both proteins were preferentially localized in the cytoplasm of epithelial cells in the epithelium lining the cystic cavity and the epithelial chords of epithelized granulomas. Additionally, SERPINB1 was expressed in infiltrating polymorph nuclear neutrophils. The expression of HSP27 and SERPINB1 demonstrated a negative correlation with acute inflammation biomarkers. Overall, these genes and protein biomarkers may be promissory targets to predict the risk profile for periodontal and periapical inflammatory bone resorption.(AU)

A periodontite crônica e a periodontite apical são doenças infecciosas caraterizadas pela destruição inflamatória dos tecidos de suporte dentários. O fenótipo clínico de ambas as doenças é o resultado da interação entre os microrganismos infectantes e os mecanismos de defesa do hospedeiro (barreira hospedeiro/patógeno). Ainda, variações genéticas podem conferir níveis diferenciais de susceptibilidade a tais doenças, teoricamente modulando tanto os padrões de infecção como de resposta do hospedeiro. Neste contexto, investigamos a associação de variações genéticas selecionadas com fenótipos de resistência e susceptibilidade a lesões osteolíticas periodontais e periapicais, assim como possíveis associações com mudanças no perfil microbiológico sub gengival e em marcadores de resposta do hospedeiro. O polimorfismo rs4794067 (no gene TBX21) demonstrou uma associação significativa com risco aumentado de sofrer periodontite crônica. Os portadores do alelo polimórfico apresentaram uma expressão significativamente aumentada de Tbet. No entanto, a expressão de IFN-γ e a carga bacteriana mostraram-se independentes do perfil genético para rs4794067. O polimorfismo rs333 (também conhecido como CCR5Δ32, no gene CCR5) demonstrou um efeito protetor para periodontite crônica. Os pacientes heterozigotos exibiram níveis de expressão significativamente diminuídos de TNF-α, porém, os níveis bacterianos mostraram-se independentes do perfil genético para rs333. Os polimorfismos rs2521634 (no gene NPY), rs10010758 (no gene TBC1D), rs6667202 (no gene IL10) e rs10043775 (no gene TBXO38) demostraram uma associação significativa com mudanças no perfil microbiológico sub gengival em pacientes com periodontite crônica. No caso da periodontite apical, escolhemos uma metodologia de seleção de marcadores baseada no uso consecutivo de eletroforeses diferencial bidimensional e espectrometria de massa. Dentre os marcadores que apresentaram uma modulação significativa, as lesões de periodontite apical demostraram uma supraregulação de HSP27 e SERPINB1. Ambas as proteínas foram preferencialmente imunomarcadas nas ilhas epiteliais dentro das lesões. A expressão de HSP27 e SERPINB1 apresentou uma correlação negativa com os marcadores de inflamação aguda. Assim sendo, estes genes e biomarcadores proteicos mostram-se como alvos promissórios para a determinação do perfil de risco de lesões osteolíticas periodontais e periapicais.(AU)

IL-6 and IL-10 gene polymorphisms in patients with aggressive periodontitis: effects on GCF, serum and clinic parameters

Abstract Genetic variations observed in cytokines affect periodontitis susceptibility. The aim of this study was to investigate interleukin(IL)-6(-174) and IL-10(-597) gene polymorphisms in generalized aggressive periodontitis (GAgP) patients. Also, we aimed to evaluate the effects of IL-6 and IL-10 gene polymorphisms on the clinical outcomes of non-surgical periodontal therapy and cytokine levels in gingival crevicular fluid(GCF) and serum. Fifty-three patients with GAgP and 50 periodontally healthy individuals were included in this study. Clinical parameters, GCF and blood samples were collected at baseline and at 6-week. Non-surgical periodontal therapy was performed in patients with GAgP. Gene analysis were determined by PCR-RFLP(polymerase chain reaction-restriction fragment length polymorphism) and cytokine levels were determined by enzyme-linked immunosorbent assay(ELISA).GAgP patients showed significant improvement on clinical parameters after periodontal therapy(p<0.05). In the GAgP group, IL-6 GG genotype and G allele frequency were higher than in the control group. GCF IL-6 level was also significantly lower at 6-week in the GAgP group. Higher GCF IL-10 levelswere observed in patients carrying the IL-6 GG genotype than in those carrying the GC+CC genotype at baseline. In conclusion, IL-6(-174) and IL-10(-597) gene polymorphisms were found to be associated with GAgP and genotype distribution did not affect the outcome of non-surgical periodontal therapy, while patients with IL-6(-174) GG genotype had higher levels of GCF IL-10 levels.

Analysis of polymorphisms in Interleukin 10, NOS2A, and ESR2 genes in chronic and aggressive periodontitis.

The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the IL10, NOS2A, and ESR2 genes and chronic periodontitis (CP) and aggressive periodontitis (AgP). Three groups of patients underwent periodontal and radiographic evaluations: CP (n = 61), AgP (n = 50), and periodontally healthy (control group=61). Genomic DNA was extracted from oral epithelial cells and used for genotyping by real-time polymerase chain reaction using TaqMan® probes. The investigated SNPs were: -1087G > A, -819C > T and -592C > A in the IL10; +2087G > A in the NOS2A, and +1730G > A in the ESR2 gene. Differences in genotype and allele frequencies of each polymorphism and some individual characteristics were analyzed using the chi-square test and multivariate logistic regression analysis. Analysis of SNPs and haplotypes in the IL10 and SNP in the ESR2 gene did not present any significant association with AgP or CP. The +2087G allele of the NOS2A gene tended to be significantly associated with periodontal disease. Patients carrying the genotype +2087GG in the NOS2A gene were genetically protected against the development of CP (p = 0.05; OR = 0.44; 95%CI = 0.20-0.95). This result showed greater significance when patients with AgP and CP were combined (total PD) (p = 0.03; OR = 0.46; 95%CI = 0.23-0.92). In conclusion, the studied Brazilian population had a significantly higher frequency of the GG genotype for the +2087 SNP in the NOS2A gene in individuals without periodontitis, although statistical significance was not maintained after multiple logistic regression.