Raquel Mantuaneli Scarel-Caminaga

Interleukin-2 and interleukin-6 gene promoter polymorphisms, and early failure of dental implants.

Single nucleotide polymorphisms in the promoter region of the human interleukin (IL)-2 (T-330G) and IL-6 (G-174C) genes have modified the transcriptional activity of these cytokines and are associated with several diseases. The aim of this study was to investigate the possible relationship between these single nucleotide polymorphisms and early implant failure. A sample of 74 nonsmokers was divided into 2 groups: test group comprising 34 patients (mean age 49.3 years) with ≥1 implants that failed and control group consisting of 40 patients (mean age 43.8 years) with ≥1 healthy implants. Genomic deoxyribonucleic acid from oral mucosa was amplified by polymerase chain reaction and analyzed by restriction fragment length polymorphism. Monte Carlo simulations (P < 0.05) were used to assess differences in allele and genotypes frequencies of the single nucleotide polymorphisms between the 2 groups. No significant differences were observed in the allele and genotypes distribution of both polymorphisms when the 2 groups were compared. The results indicate that polymorphisms in the IL-2 (T-330G) and IL-6 (G-174C) genes are not associated with early implant failure, suggesting that the presence of those single nucleotide polymorphisms does not constitute a genetic risk factor for implant loss in the studied population.

Family-Based Genetic Association for Molar-Incisor Hypomineralization.

Despite some evidence of genetic and environmental factors on molar-incisor hypomineralization (MIH), its aetiology remains unclear. This family-based genetic association study aimed more comprehensively to investigate the genetic carriage potentially involved in MIH development. DNA was obtained from buccal cells of 391 individuals who were birth family members of 101 Brazilian nuclear families. Sixty-three single nucleotide polymorphisms (SNPs) were investigated in 21 candidate genes related to amelogenesis using the TaqMan™ OpenArray™ Genotyping platform. All SNPs were genotyped in 165 birth family members unaffected by MIH, 96 with unknown MIH status and 130 affected individuals (50.7% with severe MIH). Association analysis was performed by the transmission/disequilibrium test (TDT), and statistical results were corrected using the false discovery rate. Significant results were obtained for SNPs rs7821494 (FAM83H gene, OR = 3.7; 95% CI = 1.75-7.78), rs34367704 (AMBN gene, OR = 2.7; 95% CI = 1.16-6.58), rs3789334 (BMP2 gene, OR = 2.9; 95% CI = 1.34-6.35), rs6099486 (BMP7 gene, OR = 2.2; 95% CI = 1.14-4.38), rs762642 (BMP4 gene, OR = 2.3; 95% CI = 1.38-3.65), rs7664896 (ENAM gene, OR = 2.1; 95% CI = 1.19-3.51), rs1711399 (MMP20 gene, OR = 0.4; 95% CI = 0.20-0.72), rs1711423 (MMP20 gene, OR = 2.1; 95% CI = 1.18-3.61), rs2278163 (DLX3 gene, OR = 2.8; 95% CI = 1.26-6.41), rs6996321 (FGFR1 gene, OR = 2.7; 95% CI = 1.20-5.88), and rs5979395 (AMELX gene, OR = 11.7; 95% CI = 1.63-84.74). Through this family-based association study, we concluded that variations in genes related to amelogenesis were associated with the susceptibility to develop MIH. This result is in agreement with the multifactorial idea of the MIH aetiology, but further studies are necessary to investigate more thoroughly the factors that could influence MIH.

Association between interleukin-8 levels and chronic periodontal disease: A Prisma-compliant systematic review and meta-analysis

Background: Current publications present contradictory findings regarding interleukin-8 (IL-8) levels in patients with chronic periodontitis (CP). This systematic review compile evidences of the IL8 mRNA and protein levels in gingival tissue, saliva, and gingival crevicular fluid (GCF) investigated in patients with CP. Moreover, 2 meta-analyses were made focusing on the IL-8 levels in GCF and saliva of patients with or without CP. Methods: Electronic searches of the PubMed, Web of Science, and Scopus databases were conducted for publications up to February 2016 that investigated the levels of IL-8 detected in individuals with CP compared with health individuals. A total of 31 publications were included in the systematic review. For meta-analyses, the strength of association was calculated by pooled odds ratios with 95% confidence intervals using RevMan 5.1 software. Heterogeneity was examined using Higgins I-squared, tau-squared, and &khgr;2 tests. Results: In biopsies of gingival tissue of CP patients, all studies found higher IL8 mRNA levels, and the majority of studies showed higher IL-8 protein levels in this tissue of individuals with moderate to severe CP. Four studies investigating the IL-8 levels in saliva showed inconclusive results. In spite of some studies seemed to indicate higher levels of IL-8 in GCF of CP patients, the meta-analysis results showed significantly lower IL-8 levels (pg/&mgr;L) in GCF of CP patients in comparison with periodontally healthy subjects. Conclusions: We concluded that IL8 gene expression and IL-8 protein levels were higher in gingival tissues of CP patients when compared to periodontally health individuals. Meta-analysis of studies that measured IL-8 (pg/uL) in GCF found lower levels in CP patients. There are conflicting evidences regarding IL-8 levels in saliva.

Association of Interleukin 4 Gene Polymorphisms With Dental Implant Loss

Purpose:The purpose of this study was to investigate the association between interleukin 4 (IL4) polymorphisms/haplotypes and dental implant loss. Materials and Methods:Two hundred and seventy eight (n = 278) unrelated patients were divided into 2 groups: (1) control group (C) composed of 186 individuals presenting at least 1 osseointegrated implant and (2) study group (S) composed of 94 individuals presenting at least 1 implant loss. After DNA collection, IL4 polymorphisms were investigated by polymerase chain reaction (PCR)-restriction fragment length polymorphism and for the variable number of tandem repeat (VNTR) only by PCR. Results:No association between alleles/genotypes of −590 (C/T) (P = 0.9704/P = 0.5992) and VNTR (P = 0.7155/P = 0.8789) polymorphisms and implant loss were found between the groups. Regarding +33 (C/T) polymorphism, no difference was found in genotype frequency (P = 0.1288), but the C allele was associated with implant loss (P = 0.0236, odds ratio = 1.61, 95% confidence interval = 1.1–2.4). Haplotype analysis showed no statistical differences between the groups. Conclusion:The C allele of the +33 (C/T) polymorphism in the IL4 gene was associated with susceptibility to dental implant loss in Brazilians in the studied population.

Dyslipidemia rather than Type 2 Diabetes Mellitus or Chronic Periodontitis Affects the Systemic Expression of Pro- and Anti-Inflammatory Genes

A high percentage of type 2 diabetes mellitus (T2D) patients are also affected by dyslipidemia and chronic periodontitis (CP), but no studies have determined the gene expression in patients that are simultaneously affected by all three diseases. We investigated the systemic expression of immune-related genes in T2D, dyslipidemia, and CP patients. One hundred and fifty patients were separated into five groups containing 30 individuals each: (G1) poorly controlled T2D with dyslipidemia and CP; (G2) well-controlled T2D with dyslipidemia and CP; (G3) normoglycemic individuals with dyslipidemia and CP; (G4) healthy individuals with CP; (G5) systemic and periodontally healthy individuals. Blood analyses of lipid and glycemic profiles were carried out. The expression of genes, including IL10, JAK1, STAT3, SOCS3, IP10, ICAM1, IFNA, IFNG, STAT1, and IRF1, was investigated by RT-qPCR. Patients with dyslipidemia demonstrated statistically higher expression of the IL10 and IFNA genes, while IFNG, IP10, IRF1, JAK1, and STAT3 were lower in comparison with nondyslipidemic patients. Anti-inflammatory genes, such as IL10, positively correlated with parameters of glucose, lipid, and periodontal profiles, while proinflammatory genes, such as IFNG, were negatively correlated with these parameters. We conclude that dyslipidemia appears to be the primary disease that is associated with gene expression of immune-related genes, while parameters of T2D and CP were correlated with the expression of these important immune genes.

Absence of association between transforming growth factor-beta1 promoter polymorphisms and hypodontia.

Hypodontia, the congenital absence of one or a few teeth, is one of the most common alterations of the human dentition. The most common permanent missing teeth are the third molars, second premolars, and maxillary lateral incisors. Although hypodontia does not represent a serious public health problem, it may cause masticatory and speech dysfunctions and esthetic problems. Transforming growth factor-beta1 (TGF-beta1) is believed to play an important role in tooth development. Its gene is expressed at bud, cap, and bell stages of odontogenesis. Genetic polymorphisms in the TGF-beta1 gene promoter were shown to interfere with the transcriptional activity of this gene. To further investigate the role of the TGF-beta1 gene in human hypodontia, we analyzed the frequencies of the -509 polymorphism (C-T) alleles and -800 polymorphism (G-A) alleles and genotypes in the TGF-beta1 gene promoter in 51 Caucasian subjects with hypodontia and 48 control individuals. Our data suggest that these TGF-beta1 promoter polymorphisms are not associated with hypodontia.

Functional Haplotypes in Interleukin 4 Gene Associated with Periodontitis

Chronic periodontitis (CP) is an infectious inflammatory disease that affects tooth-supporting structures and in which dental plaque bacteria, immune mechanisms and genetic predisposition play important roles. Interleukin 4 (IL-4) is a key anti-inflammatory cytokine with relevant action in imbalances in inflamed periodontal tissue. Individuals carrying the TCI/CCI genotype (S-haplotype) of the IL-4 gene are 5 times more susceptible to CP, whereas the CTI/TTD genotype (P-haplotype) confers protection against CP. Compared with the S-haplotype, subjects with the P-haplotype produce higher levels of the IL-4 protein after non-surgical periodontal therapy. The present in vitro study aimed to investigate the functionality of IL-4 haplotypes in immune cells to obtain insight into the influence of these genetic variations in regulating immune responses to CP-associated bacteria. Peripheral blood was collected from 6 subjects carrying each haplotype, and their immune cells were challenged with periodontopathogens to compare responses of the different haplotypes with regard to gene expression, protein secretion and the immunophenotype of T helper responses. We found higher IL-4 mRNA and protein levels in the P-haplotype, which also presented higher levels of anti-inflammatory cytokines. In contrast, cells from S-haplotype subjects responded with higher levels of pro-inflammatory cytokines. S-haplotype individuals exhibited significantly greater polarization toward the Th1 phenotype, whereas the P-haplotype was associated with an attenuated response to periodontopathogens, with suggestive skewing toward Th2/M2 phenotypes. In conclusion, IL-4 genetic variations associated with susceptibility to or protection against chronic periodontitis are directly associated with influencing the response of immune cells to periodontopathogens.

Expression Profile of Genes Potentially Associated with Adequate Glycemic Control in Patients with Type 2 Diabetes Mellitus

Despite increasing research in type 2 diabetes mellitus (T2D), there are few studies showing the impact of the poor glycemic control on biological processes occurring in T2D. In order to identify potential genes related to poorly/well-controlled patients with T2D, our strategy of investigation included a primary screen by microarray (Human Genome U133) in a small group of individuals followed by an independent validation in a greater group using RT-qPCR. Ninety patients were divided as follows: poorly controlled T2D (G1), well-controlled T2D (G2), and normoglycemic individuals (G3). After using affy package in R, differentially expressed genes (DEGs) were prospected as candidate genes potentially relevant for the glycemic control in T2D patients. After validation by RT-qPCR, the obtained DEGs were as follows—G1 + G2 versus G3: HLA-DQA1, SOS1, and BRCA2; G2 versus G1: ENO2, VAMP2, CCND3, CEBPD, LGALS12, AGBL5, MAP2K5, and PPAP2B; G2 versus G3: HLA-DQB1, MCM4, and SEC13; and G1 versus G3: PPIC. This demonstrated a systemic exacerbation of the gene expression related to immune response in T2D patients. Moreover, genes related to lipid metabolisms and DNA replication/repair were influenced by the glycemic control. In conclusion, this study pointed out candidate genes potentially associated with adequate glycemic control in T2D patients, contributing to the knowledge of how the glycemic control could systemically influence gene expression.

Genes Regulating Immune Response and Amelogenesis Interact in Increasing the Susceptibility to Molar-Incisor Hypomineralization

Ameloblasts are sensitive cells whose metabolism and function may be affected by inflammatory stimuli. The aim of this study was to evaluate the possible association between polymorphisms in immune response-related genes and molar-incisor hypomineralization (MIH), and their interaction with polymorphisms in amelogenesis-related genes. DNA samples were obtained from 101 nuclear families that had at least 1 MIH-affected child. Eleven single-nucleotide polymorphisms (SNPs) were investigated in immune response genes using TaqMan® technology allele-specific probes. A transmission disequilibrium test was performed to verify overtransmission of alleles in all MIH families, as well as in families only with mild or severe MIH-affected children. Gene-gene interactions between the immune-related and amelogenesis-related polymorphisms were analyzed by determining whether alleles of those genes were transmitted from heterozygous parents more often in association than individually with MIH-affected children. In severe cases of MIH, significant results were observed for rs10733708 (TGFBR1, OR = 3.5, 95% CI = 1.1–10.6). Statistical evidence for gene-gene interactions between rs6654939 (AMELX) and the SNPs rs2070874 (IL4), rs2275913 (IL17A), rs1800872 (IL10), rs1800587 (IL1A), and rs3771300 (STAT1) was observed. The rs2070874 SNP (IL4) was also significantly overtransmitted from heterozygous parents with the rs7526319 (TUFT1) and the rs2355767 (BMP2) SNPs, suggesting a synergistic effect of the transmission of these alleles with susceptibility to MIH. This family-based study demonstrated an association between variation in TGFBR1 and MIH. Moreover, the polymorphisms in immune response and amelogenesis genes may have an additive effect on the risk of developing MIH.

The Yngve Ericsson Prize: Progress in Prophylactic Dentistry Research Awarded

imal intervention dentistry concept. His latest line of research has resulted in the development of a novel carious lesion assessment and treatment instrument (CAST) for use in epidemiological studies. Dr. Frencken’s solid and highly dedicated research has contributed greatly to the prevention of dental diseases and to increasing the accessibility of oral health care for many individuals and population groups in different countries worldwide. Panos Papapanou is Professor of Dental Medicine, Director of the Division of Periodontics, and Chairman of The 2016 Yngve Ericsson Prize for Research in Preventive Odontology has been awarded jointly to Professor Jo Frencken of Radboud University, Nijmegen, the Netherlands, and Professor Panos Papapanou of Columbia University, New York, NY, USA. The Prize of SEK 400,000 (approx. EUR 43,000) is to be shared equally between the two recipients and will be awarded at the ORCA Congress in July in Athens, Greece. Jo Frencken, Associate Professor Emeritus in Minimal Intervention Dentistry at the College of Dental Sciences of the Radboud University Medical Centre in Nijmegen, is a public health specialist by training. His early experience, in Malawi, Africa, of the many facets of oral health in the absence of regular dental care significantly altered his perception on how dental caries might be managed, and this led him to reconsider how oral care can be made available for an increasing number of people and communities. Dr. Frencken’s research has thus mainly focused on caries prevention and on providing dental care by principles that were earlier deemed less justifiable but currently considered as valid, given the fact that low-income populations cannot afford the well-known standards of oral care. He pioneered the development of the ART (atraumatic restorative treatment) concept and was instrumental in researching the many aspects of this minPublished online: June 4, 2016