Lack of association between LTF gene polymorphisms and different caries status in primary dentition

Association between polymorphisms of immune response genes and early childhood caries - systematic review, gene-based, gene cluster, and meta-analysis

BACKGROUND

Early childhood caries is a significant public health concern affecting about 600 million children globally. The etiology of early childhood caries can be explained as an interplay between genetic and environmental factors. Single nucleotide polymorphisms are the most common variations in the human genome. Genetic variations of immune response genes can modify the defense response of the host, and alter the susceptibility to bacterial colonization of the oral cavity and early childhood caries. The aim of this systematic review is to identify genetic variants of immune response genes associated with early childhood caries.

RESULTS

A total of 7124 articles were identified by conducting an elaborate search across various electronic databases and genome-wide association studies databases. Subsequent to exclusion at various stages, fifteen articles qualified to be included into the present review. Risk of bias assessment was done with the Q-genie tool. Quantitative synthesis revealed that the odds ratio for TT and CC genotypes of rs11362 was 1.07 (0.67-1.71) and 1.16 (0.84-1.60), respectively. Gene-based analysis revealed a statistically significant association between variants of tumor necrosis factor-alpha gene and T-cell receptor alpha variable 4 locus with early childhood caries. Gene clustering showed the presence of three functional clusters. To comprehend the protein-protein interaction, the bioinformatic tool of "Search Tools for the Retrieval of Interacting Genes and Proteins" was used. Among the biological processes and the reactome pathways, complement activation through the lectin pathway showed the highest strength of association with early childhood caries. To understand the interaction and functionality of the genes, "gene function prediction using Multiple Association Network Integration Algorithm" was used, which revealed that the genes were linked by physical interaction (39.34%) and through co-expression (34.88%).

CONCLUSIONS

Genotype TT of rs7217186 of arachidonate 15-lipoxygenase gene was a risk factor for early childhood caries. Multiple genetic variants of T-cell receptor alpha variable 4 locus and tumor necrosis factor-alpha gene were associated with increased susceptibility to early childhood caries. Polymorphisms of genes regulating the lectin pathway of complement activation can modify the susceptibility to early childhood caries.

Impact of tooth mineral tissues genes on dental caries: a birth-cohort study

OBJECTIVE

We aimed to investigate whether Single Nucleotide Polymorphisms present in the genes of tooth mineral tissues influence dental caries trajectory across the life course, and if there is an epistatic (gene-gene) interaction between these SNPs.

METHODS

A representative sample of all 5,914 births from the 1982 Pelotas birth cohort study was prospectively investigated. Dental caries trajectory across the life course was assessed at 15(n=888), 24(n=720), and 31 years old(n=539). Group-based trajectory modelling was used to identify distinct subgroups of individuals whose caries measurements followed a similar pattern over time. Genetic material was collected, and individuals were genotyped [rs4970957(TUFT1), rs1711437(MMP20), rs1784418(MMP20), rs2252070(MMP13), rs243847(MMP2), rs2303466(DLX3), rs11656951(DLX3), rs7501477(TIMP2), rs388286(BMP7), and rs5997096(TFIP11)]. Analyzes were performed for allele and genotype using logistic regression and generalized multifactor dimensionality reduction for epistatic interactions.

RESULTS

The analyses included 678 individuals, those with allele C (OR=0.74, CI95%[0.59-0.92]), genotype CC in the additive effect (OR=0.52, CI95%[0.31-0.89]), and the genotype TC/CC in dominant effect (OR=0.72, CI95%[0.53-0.98]) on the rs243847(MMP2) were associated with low caries trajectory. Individuals with the allele T (OR=0.79, CI95%[0.64-0.98]) and the genotype TC/CC in dominant effect (OR=0.66, CI95%[0.47-0.95]) on the rs5997096(TFIP11) were associated with low caries trajectory. Positive epistatic interactions were observed involving two (MMP2 and BMP7; p=0.006) and three (TUFT1, MMP2, and TFIP11; p<0.001) loci and high caries trajectory.

CONCLUSIONS

Some SNPs present in the genes of tooth mineral tissues were associated with caries trajectory and epistatic interactions increasing the network of SNPs involved in individual caries experience.

CLINICAL SIGNIFICANCE

Single nucleotide polymorphisms in the pathway of tooth mineral tissues genes may contribute significantly to the individual caries experience across the life course.

Sweet Taste Receptor Gene and Caries Trajectory in the Life Course

This study aims to investigate whether the trajectory of dental caries in the life course is associated with rs307355 (TAS1R3) and rs35874116 (TAS1R2) and if there is an epistatic association between rs307355 (TAS1R3) and rs35874116 (TAS1R2). A representative sample of all 5,914 births from the 1982 Pelotas birth cohort was prospectively investigated, and the decayed, missing, and filled teeth (DMF-T) components were assessed at ages 15 (n = 888), 24 (n = 720), and 31 (n = 539) y. Group-based trajectory modeling was used to identify groups with similar trajectories of DMF-T components in the life course. Genetic material was collected, and rs307355 (TAS1R3) and rs35874116 (TAS1R2) were genotyped. Ethnicity was evaluated using ADMIXTURE. Generalized multifactor dimensionality reduction software was used to investigate epistatic interactions. Considering rs307355 (TAS1R3) in the additive effect, the genotype TT was associated with the high decayed trajectory group (odds ratio [OR] = 4.52; 95% confidence interval [CI], 1.15-17.74) and the high missing trajectory group (OR = 3.35; 95% CI, 1.09-10.26). In the dominant effect, the genotype CT/TT was associated with the high decayed trajectory group (OR = 1.64; 95% CI, 1.14-2.35). Allele T was associated with an increased odds of 64% (OR = 1.64; 95% CI, 1.20-2.25) for the decayed component and 41% (OR = 1.41; 95% CI, 1.04-1.92) for the missing component. No associations were observed between rs307355 (TAS1R3) and the filled component. rs35874116 (TAS1R2) was not associated with DMF-T components. Positive epistatic interactions were observed involving rs307355 (TAS1R3) and rs35874116 (TAS1R2) with the decayed component (OR = 1.72; 95% CI, 1.04-2.84). Thus, rs307355 (TAS1R3) genotypes and alleles seem positively associated with the trajectory of decayed and missing components in the life course. Epistatic interaction between rs307355 and rs35874116 may increase the decayed caries trajectory.

Association of polymorphisms in genes involved in enamel formation, taste preference and immune response with early childhood caries in Saudi pre-school children

Dental caries is primarily elicited by modifiable factors such as inadequate oral hygiene, poor dietary practices and deficient fluoride exposure. However, there is a growing body of evidence suggesting the profound influence of genetic factors in dental caries susceptibility. The present study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in ENAM (rs12640848), MMP20 (rs1784418), TAS2R38 (rs713598), and LTF (rs4547741) genes and early childhood caries (ECC) in Saudi preschool children. This case-control study enrolled 360 Saudi preschool children (262 with ECC and 98 caries-free). Data on environmental factors were collected through a questionnaire. However, caries experience and oral hygiene data were obtained during clinical examination. Buccal swab samples were collected for DNA extraction and SNPs were genotyped using PCR and DNA sequencing. Children with ECC were compared to caries free children (control), then they were categorized into two categories based on ECC severity as follows; non-severe ECC (NS-ECC), and severe-ECC (S-ECC). Association between the SNPs, ECC, NS-ECC, and S-ECC was reported as an odds ratio (OR) with a 95% confidence interval (CI). The majority of the children (72.8%) exhibited ECC (31.7% NS-ECC and 41.1% S-ECC) with mean dmft of 4.20 ± 4.05. Multivariate analyses of environmental factors showed that nocturnal feeding was a risk factor for ECC (P = 0.008). Poor oral hygiene was also a risk factor for both NS-ECC and S-ECC (ECC: P < 0.0001, NS-ECC: P = 0.032 and S-ECC: P < 0.0001). Univariate analysis showed that the AG genotype of rs1784418 of MMP20 gene was protective against ECC (OR = 0.532; 95% CI = 0.316-0.897, P = 0.018) and against NS-ECC (OR = 0.436; 95% CI = 0.238-0.798, P = 0.007). When environmental risk factors for ECC were included as covariates during multivariate analysis, AG variant in rs1784418 of MMP20 gene remained less frequent in NS-ECC cases compared to controls with borderline significance (OR = 0.542; 95% CI = 0.285-1.033, P = 0.063). Our findings concluded that MMP20 rs1784418 SNP might be associated with protection against ECC in Saudi preschool children.

Genes and SNPs in the pathway of immune response and caries risk: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to pool the data on Single Nucleotide Polymorphisms (SNPs) in immune response genes associated with dental caries. Nineteen studies were included in the review and 18 in the meta-analysis. Twenty-two SNPs were evaluated, which are linked to six different genes (MBL2, LFT, MASP2, DEFB1, FCN2 and MUC5B). Most SNPs (81.8%) are related to the possible functional impact on protein coding. The MBL2 gene was associated with caries experience in the analysis of the homozygote (OR = 2.12 CI95%[1.12-3.99]) and heterozygote (OR = 2.22 CI95%[1.44-3.44]) genotypes. The MUC5B gene was associated according to an analysis of the heterozygous genotype (OR = 1.83 CI95%[1.08-3.09]). Thus, SNPs related to immune response genes are linked to the phenotype of caries experience. Although the meta-analysis showed that the genes MBL2 and MUC5B were associated with caries, these results should be interpreted with caution due to the quality of the evidence.

Lack of associations between lactoferrin (LTF) and mannose-binding lectin 2 (MBL2) gene polymorphism and dental caries susceptibility

Objective

With the development of human genomics, the genetic factors associated with dental caries have receiving increasing attention. This study was performed to evaluate the relationship between lactoferrin (LTF) and mannose-binding lectin 2 (MBL2) gene single nucleotide polymorphisms (SNPs) and dental caries susceptibility in Chinese children.

Methods

This prospective case–control study included 360 unrelated children (aged 12–15 years) who received oral health examinations and questionnaire surveys. The children were divided into two groups by counting the numbers of decayed, missing, and filled teeth (DMFT/dmft): case group (n = 162, DMFT/dmft ≥ 1) and control group (n = 198, DMFT/dmft = 0); non-invasive saliva samples were collected to extract genomic DNA. Six SNPs (rs2073495C/G, rs1042073C/T, rs10865941C/T, and rs1126477A/G in LTF; rs7096206C/G and rs7095891G/A in MBL2) were tested by mass spectrometry.

Results

The study included 360 individuals with (85 boys and 77 girls) and without a history of caries (96 boys and 102 girls). There were no statistically significant differences in alleles and genotypes among the six SNPs between the two groups.

Conclusion

There is no evidence that polymorphisms of LTF and MBL2 genes are associated with dental caries susceptibility in populations from northwest China; further confirmation is needed with larger sample sizes.

The association between genetic variants in lactotransferrin and dental caries: a meta- and gene-based analysis

BACKGROUND

The pathogenesis of dental caries remains unclear, with increasing evidence suggesting that genetic susceptibility plays an essential role. Previous studies have reported the association between genetic polymorphisms in lactotransferrin (LTF) and the risk of dental caries with inconsistent results.

METHODS

A systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases was performed by two authors independently for papers published before December 5, 2019 on the association between genetic variants in LTF and the risk of dental caries. We adopted the subsequent inclusion criteria to assess study eligibility: 1) The studies were based on human subjects; 2) the presence of dental caries should be screened for in both the case group and the control group; and 3) genotype data on variants in LTF were available in both the case group and the control group. We calculated odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) by using random-effects models to assess the association of genetic variants in LTF with the risk of dental caries. We also performed a gene-based analysis to explore the joint association of multiple genetic variants in LTF with the risk of dental caries.

RESULTS

Our systematic literature search identified six relevant papers for analysis. We found no significant association between rs1126478 and the risk of dental caries when meta-analysing the genotype distribution between subjects with dental caries and those without dental caries (additive model: OR = 1.41; 95% CI = 0.98-2.02; P = 0.065). However, further analysis indicated that rs1126478 was associated with dental risk in subjects who had moderate or severe dental caries compared to those without dental caries (P < 0.0001). The gene-based analysis indicated that multiple genetic variants in LTF were jointly associated with the risk of dental caries (P = 0.002).

CONCLUSIONS

The present meta-analysis revealed some evidence of the association between rs1126478 and dental caries and that multiple genetic variants in LTF are jointly associated with the risk of dental caries. Our findings need to be validated by larger studies that adjust for important confounding factors for the risk of dental caries.

Association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility: a meta-analysis

Background

This meta-analysis evaluated the association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility.

Methods

We searched the Scopus, PubMed/Medline, Web of Science, and Cochrane Library databases to retrieve articles published by October 2019. Review Manager 5.3 software was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). The results of publication bias tests were retrieved by Comprehensive Meta-Analysis 2.0 software.

Results

A total of 150 relevant records were identified; out of which, 16 were entered into the analysis (4 studies assessed LTF, 11 ENAM, and 11 AMELX polymorphisms). Of all polymorphisms, there was a significant association only between ENAM rs3796704 polymorphism and dental caries susceptibility. Both ENAM rs3796704 and AMELX rs17878486 polymorphisms had a significant association with dental caries risk in the Caucasian ethnicity and the studies including caries-free control group.

Conclusions

The results of this meta-analysis showed that the G allele and the GG genotype of ENAM rs3796704 were associated with an increased risk of caries in the case group compared with the control group. But there was no association between LTF rs1126478, ENAM (rs1264848 and rs3796703), and AMELX (rs946252, rs17878486, and rs2106416) polymorphisms and dental caries susceptibility.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This comprehensive review of the 2018 dental literature is provided to inform busy dentists about progress in the profession. Developed by the Committee on Scientific Investigation of the American Academy of Restorative Dentistry, each author brings discipline-specific expertise to one of the 8 sections of the report including (1) prosthodontics; (2) periodontics, alveolar bone, and peri-implant tissues; (3) implant dentistry; (4) dental materials and therapeutics; (5) occlusion and temporomandibular disorders; (6) sleep-related breathing disorders; (7) oral medicine and oral and maxillofacial surgery; and (8) dental caries and cariology. The report targets important information that will likely influence day-to-day treatment decisions. Each review is not intended to stand alone but to update interested readers so that they may visit source materials if greater detail is desired. As the profession continues its march toward evidence-based clinical decision-making, an already voluminous library of potentially valuable dental literature continues to grow. It is the intention of this review and its authors to provide assistance in navigating the extensive dental literature published in 2018. It is our hope that readers find this work useful in the clinical management of patients moving forward.