Enamelin Research Articles

ENAM gene polymorphisms associated with dental anomalies in individuals with cleft lip and palate

Aim: This study aimed to investigate the occurrence of enamelin gene (ENAM) single nucleotide polymorphisms (SNP) and ENAM polymorphism association with dental anomalies (DA) in individuals with unilateral or bilateral cleft lip and palate (CLP). Methods: Saliva samples were collected from 147 individuals aged between 6 and 15 years-old, both genders, and divided into 4 groups: Group 1 (G1) - CLP and DA; Group 2 (G2) - CLP without DA; Group 3 (G3) - without CLP with DA; Group 4 (G4) - without CLP and DA. The genomic DNA was extracted from saliva samples and the following ENAM SNPs markers were genotyped: rs3796703, rs3796704, rs3796705, rs7671281, rs2609428, and rs35951442. Fisher exact and Pearson’s Chi-square tests statistically analyzed the results (α=5%). Results: Individuals without CLP with DA (Group 3 - 19.2%) showed statistically higher prevalence of SNP rs2609428 heterozygotes (p=0.006) than individuals with CLP and DA (Group 1 - 0%). Individuals without CLP (10%) exhibited statistically higher prevalence of mutated heterozygotes/homozygous (p=0.028) than in individuals with CLP (1.3%). Conclusion: SNP rs2609428 marker of ENAM gene may be associated with dental anomalies in individuals without cleft lip and palate.

Genetic variations in exon 10 of ENAM and their association with early childhood caries

ObjectiveEnamelin is the largest enamel matrix protein encoded by the ENAM gene. The primary purpose of this study was to identify genetic variants in ENAM exon 10 that can alter susceptibility to early childhood caries (ECC). MethodsThis case-control study included 248 children aged 3–6 years, with 124 children diagnosed with ECC in the case group and 124 children without caries in the control group. Questionnaires were used to record demographic data, socioeconomic status, hygienic practices, and feeding practices, and a 24-h diet diary was kept. Seven polymorphisms (rs7671281, rs1738668322, rs3796703, rs3796704, rs759376039, rs775159311, and rs1738678483) in ENAM exon 10 were sequenced. ResultsThe heterozygous CT genotype of rs7671281 was significantly more common in the case group compared to the control group (odds ratio [OR], 6.1765; 95% confidence interval [CI], 2.05–18.58; P = 0.0006). Under the dominant model, the TT genotype of rs7671281 was significantly more common in the control group (OR, 6.47; 95% CI, 2.15–19.39; P < 0.001). The AG genotype of rs3796704 was significantly more common in the case group than in the control group (OR, 5.705; 95% CI, 1.60–20.25; P = 0.006). Under the dominant model, the GG genotype of rs3796704 was significantly more common in children without caries than in children with caries (OR, 6.84; 95% CI, 1.96–23.90; P < 0.001). ConclusionsThe C allele of rs7671281 and the A allele of rs3796704 can increase susceptibility to ECC.

Splicing mutations in AMELX and ENAM cause amelogenesis imperfecta

BackgroundAmelogenesis imperfecta (AI) is a developmental enamel defect affecting the structure of enamel, esthetic appearance, and the tooth masticatory function. Gene mutations are reported to be relevant to AI. However, the mechanism underlying AI caused by different mutations is still unclear. This study aimed to reveal the molecular pathogenesis in AI families with 2 novel pre-mRNA splicing mutations.MethodsTwo Chinese families with AI were recruited. Whole-exome sequencing and Sanger sequencing were performed to identify mutations in candidate genes. Minigene splicing assays were performed to analyze the mutation effects on mRNA splicing alteration. Furthermore, three-dimensional structures of mutant proteins were predicted by AlphaFold2 to evaluate the detrimental effect.ResultsThe affected enamel in family 1 was thin, rough, and stained, which was diagnosed as hypoplastic-hypomature AI. Genomic analysis revealed a novel splicing mutation (NM_001142.2: c.570 + 1G > A) in the intron 6 of amelogenin (AMELX) gene in family 1, resulting in a partial intron 6 retention effect. The proband in family 2 exhibited a typical hypoplastic AI, and the splicing mutation (NM_031889.2: c.123 + 4 A > G) in the intron 4 of enamelin (ENAM) gene was observed in the proband and her father. This mutation led to exon 4 skipping. The predicted structures showed that there were obvious differences in the mutation proteins compared with wild type, leading to impaired function of mutant proteins.ConclusionsIn this study, we identified two new splicing mutations in AMELX and ENAM genes, which cause hypoplastic-hypomature and hypoplastic AI, respectively. These results expand the spectrum of genes causing AI and broaden our understanding of molecular genetic pathology of enamel formation.

Enam expression is regulated by Msx2.

The precise formation of mineralized dental tissues such as enamel and/or dentin require tight transcriptional control of the secretion of matrix proteins. Here, we have investigated the transcriptional regulation of the second most prominent enamel matrix protein, enamelin, and its regulation through the major odontogenic transcription factor, MSX2. Using in vitro and in vivo approaches, we identified that (a) Enam expression is reduced in the Msx2 mouse mutant pre-secretory and secretory ameloblasts, (b) Enam is an early response gene whose expression is under the control of Msx2, (c) Msx2 binds to Enam promoter in vitro, suggesting that enam is a direct target for Msx2 and that (d) Msx2 alone represses Enam gene expression. Collectively, these results illustrate that Enam gene expression is controlled by Msx2 in a spatio-temporal manner. They also suggest that Msx2 may interact with other transcription factors to control spatial and temporal expression of Enam and hence amelogenesis and enamel biomineralization.

AMELX and ENAM Polymorphisms and Dental Caries.

The variety of the genetic factors playing role in development of dental caries calls for further research in this regard. The aim of the present study was to investigate the differences between caries-free adults and adults with dental caries in terms of polymorphism of caries-related genes (AMELX and ENAM). The present case-control study was performed on 81 adults aged 18-24 years, 41 caries free, and 40 with a DMFT ≥ 4. A questionnaire containing background and demographic information (such as age, gender, time and type of latest dental check-ups, parent's education, oral self-care, and the place of residence in the first 12 years of life) was completed by participants at the time of examination. The blood sample was taken from each participant in the EDTA tube, and PCR was performed. Gene diversity of AMELX and ENAM genes was compared between the two groups. Regarding AMELX gene, in the caries-free group 33 (80.5%) and in the group with DMFT ≥ 4, 33 (82.5%) students had TT genotype, but this difference was insignificant. For ENAM gene, in the caries-free group 34 (82.9%) and in the group with DMFT ≥ 4, 39 (97.5%) students had TT genotype, but this difference was insignificant (P value = 0.048, CI 95%:0.02-1.27, and OR = 0.145). There was no relationship between TT and TC genotypes of single nucleotide polymorphism of AMELX and ENAM gene and susceptibility to dental caries, but with increasing sample size, there may be a relationship between SNP of ENAM gene and being caries free.

The phosphorylation of serine55 in enamelin is essential for murine amelogenesis

Amelogenesis imperfecta (AI) is an inherited developmental enamel defect affecting tooth masticatory function, esthetic appearance, and the well-being of patients. As one of the major enamel matrix proteins (EMPs), enamelin (ENAM) has three serines located in Ser-x-Glu (S-x-E) motifs, which are potential phosphorylation sites for the Golgi casein kinase FAM20C. Defects in FAM20C have similarly been associated with AI. In our previous study of EnamRgsc514 mice, the Glu57 in the S55-X56-E57 motif was mutated into Gly, which was expected to cause a phosphorylation failure of Ser55 because Ser55 cannot be recognized by FAM20C. The severe enamel defects in ENAMRgsc514 mice reminiscent of Enam-knockout mouse enamel suggested a potentially important role of Ser55 phosphorylation in ENAM function. However, the enamel defects and ENAM dysfunction may also be attributed to distinct physicochemical differences between Glu57 and Gly57. To clarify the significance of Ser55 phosphorylation to ENAM function, we generated two lines of Enam knock-in mice using CRISPR-Cas9 method to eliminate or mimic the phosphorylation state of Ser55 by substituting it with Ala55 or Asp55 (designated as S55A or S55D), respectively. The teeth of 6-day or 4-week-old mice were subjected to histology, micro-CT, SEM, TEM, immunohistochemistry, and mass spectrometry analyses to characterize the morphological, microstructural and proteomic changes in ameloblasts, enamel matrix and enamel rods. Our results showed that the enamel formation and EMP expression in S55D heterozygotes (Het) were less disturbed than those in S55A heterozygotes, while both homozygotes (Homo) had no mature enamel formation. Proteomic analysis revealed alterations of enamel matrix biosynthetic and mineralization processes in S55A Hets. Our present findings indicate that Asp55 substitution partially mimics the phosphorylation state of Ser55 in ENAM. Ser55 phosphorylation is essential for ENAM function during amelogenesis.

Distribution and Allelic Frequency of the Enamelin Gene Variant rs7671281 Associated to Amelogenesis Imperfecta and High‐risk Caries in Puerto Rico

Amelogenesis imperfecta (AI) is an inherited, rare dental disorder that affects only the formation of tooth enamel and shows both clinical and genetic heterogeneity. Similarly, the enamelin gene (ENAM) has a fundamental role in the mineralization and structural organization of enamel and any change in its sequence can affect the thickness of the enamel. The objective of this study is to be able to confirm the association between the genetic variant rs7671281 in the ENAM gene with AI and high‐risk caries subjects in the Puerto Rican population. This nonsense variant has been associated with the local, autosomal dominant hypoplastic form (type IB) of AI. Through Real‐time PCR, we determined the allelic frequency and geographic distribution of rs7671281 by genotyping 622 samples of healthy subjects from Puerto Rico. Due to its association with a reduction in enamel thickness, rs7671281 is also genotyped to check its role in the susceptibility to the risk of developing dental caries. The present study was carried out in the Puerto Rican population with phenotypes associated with amelogenesis imperfecta and subjects with a high to moderate prevalence of dental caries. In turn, subjects with a low to no prevalence of dental caries were considered as controls. Through the collection and analysis of saliva samples, the prevalence of the enamelin variant rs7671281 was confirmed in the Puerto Rican population. The island‐wide distribution pattern is non‐regionalized and influenced by coastal regions, but mostly predominated in the South and East area of the island. According to the 1000 Genomes Project, the allelic frequency of rs7671281 for the T allele was 0.885 (184) and for the C allele was 0.115 (24) based on a total of 208 samples. The present study shows a significant decrease in the allelic frequency of rs7671281 for the mutated allele C (0.0530) in comparison to the 1000 Genomes Project (0.115). Therefore, we concluded that the allelic frequencies of rs7671281 analyzed in this study are more accurate than the values given in the 1000 Genomes Project.

Mecanismos moleculares de la amelogénesis imperfecta. Una revisión de los genes ENAM, AMBN, FAM83H, MMP20 y KLK4

Amelogenesis imperfecta (AI) is an inherited disorder that affects the structure and clinical appearance of tooth enamel. Mutations of 18 genes have been associated as the etiology of AI. The objective of this work is to update the current knowledge about ENAM, AMBN, FAM83H, MMP20 and KLK4 genes that cause the different types of AI.Methodology: A bibliographic search was carried out considering scientific articles from 2003 to 2021 with regard to specific mutations in the aforementioned genes in the following portals: scielo, Pubmed / MEDLINE, Cochrane and Springer Link.Results: 37 articles met the inclusion criteria and were used for the development of this review.Conclusions: Depending on the gene involved, enamel alterations can show a variety of characteristics. The biological mechanisms that lead to the disease are multiple and varied, however many of them are not entirely clear yet, so more research will be required to improve our understanding of the subject.

Mecanismos moleculares de la amelogénesis imperfecta. Una revisión de los genes ENAM, AMBN, FAM83H, MMP20 y KLK4.

Amelogenesis imperfecta (AI) is an inherited disorder that affects the structure and clinical appearance of tooth enamel. Mutations of 18 genes have been associated as the etiology of AI. The objective of this work is to update the current knowledge about ENAM, AMBN, FAM83H, MMP20 and KLK4 genes that cause the different types of AI.Methodology: A bibliographic search was carried out considering scientific articles from 2003 to 2021 with regard to specific mutations in the aforementioned genes in the following portals: scielo, Pubmed / MEDLINE, Cochrane and Springer Link.Results: 37 articles met the inclusion criteria and were used for the development of this review.Conclusions: Depending on the gene involved, enamel alterations can show a variety of characteristics. The biological mechanisms that lead to the disease are multiple and varied, however many of them are not entirely clear yet, so more research will be required to improve our understanding of the subject.

Molecular Evolution of Tooth-Related Genes Provides New Insights into Dietary Adaptations of Mammals

Mammals have evolved different tooth phenotypes that are hypothesized to be associated with feeding habits. However, the genetic basis for the linkage has not been well explored. In this study, we investigated 13 tooth-related genes, including seven enamel-related genes (AMELX, AMBN, ENAM, AMTN, ODAM, KLK4 and MMP20) and six dentin-related genes (DSPP, COL1A1, DMP1, IBSP, MEPE and SPP1), from 63 mammals to determine their evolutionary history. Our results showed that different evolutionary histories have evolved among divergent feeding habits in mammals. There was stronger positive selection for eight genes (ENAM, AMTN, ODAM, KLK4, DSPP, DMP1, COL1A1, MEPE) in herbivore lineages. In addition, AMELX, AMBN, ENAM, AMTN, MMP20 and COL1A1 underwent accelerated evolution in herbivores. While relatively strong positive selection was detected in IBSP, SPP1, and DSPP, accelerated evolution was only detected for MEPE and SPP1 genes among the carnivorous lineages. We found positive selection on AMBN and ENAM genes for omnivorous primates in the catarrhini clade. Interestingly, a significantly positive association between the evolutionary rate of ENAM, ODAM, KLK4, MMP20 and the average enamel thickness was found in primates. Additionally, we found molecular convergence in some amino acid sites of tooth-related genes among the lineages whose feeding habit are similar. The positive selection of related genes might promote the formation and bio-mineralization of tooth enamel and dentin, which would make the tooth structure stronger. Our results revealed that mammalian tooth-related genes have experienced variable evolutionary histories, which provide some new insights into the molecular basis of dietary adaptation in mammals.

A novel ENAM mutation causes hypoplastic amelogenesis imperfecta

To identify the genetic cause of one Chinese family with hypoplastic amelogenesis imperfecta (AI) and explore the relationship between genotype and its phenotype. One Chinese family with generalized hypoplastic AI was recruited. One deciduous tooth from the proband was subjected to scanning electron microscopy. Whole-exome sequencing was performed and identified mutation was confirmed by Sanger sequencing. Bioinformatics studies were further conducted to analyze potential deleterious effects of the mutation. The proband presented a typical hypoplastic AI phenotype whose teeth in deciduous and permanent dentitions showed thin, yellow, and hard enamel surface. The affected enamel in deciduous tooth showed irregular, broken, and collapsing enamel rods with borders of the enamel prisms undulated and structural shapes of prisms irregular. A novel homozygous nonsense mutation in the last exon of the enamelin (ENAM) gene (NM_031889.3; c.2078C>G) was identified in the proband, which was predicted to produce a highly truncated protein (NP_114095.2; p.(Ser693*)). This mutation was also identified in the proband's parents in heterozygous form. Surprisingly, the clinical phenotype of the heterozygous parents varied from a lack of penetrance to mild enamel defects. Additional bioinformatics studies demonstrated that the detected mutation could change the 3D structure of the ENAM protein and severely damaged the function of ENAM. The novel homozygous ENAM mutation resulted in hypoplastic AI in the present study. Our results provide new genetic evidence that mutations involved in ENAM contribute to hypoplastic AI.

Analysis of ENAM gene single-nucleotide polymorphism rs3796704 with caries susceptibility in young adult Tamil population.

Background:Dental caries is as primeval as humanity, but still, investigations are undergoing regarding the etiopathogenesis behind this multifactorial disease. Genetics is known to play a vital role in the etiology behind dental caries in addition to environmental and socioeconomic factors. Genetic variations like single-nucleotide polymorphisms (SNPs) were extensively studied in the past decade to portray the etiopathogenesis contributing to dental caries.Aim:This investigation was undertaken to analyze the ENAM gene SNP rs3796704 with caries susceptibility in ethnic young adult Tamil population of India.Materials and Methods:Out of 370 patients included, 215 patients belonged to the high caries group (Decayed, Missing and Filled Tooth [DMFT] ≥2) and 155 patients belonged to the low caries group (DMFT ≤ 1). DNA was extracted from the blood of all the individuals. SNP genotyping was performed utilizing tetra-primer amplification refractory mutation system–polymerase chain reaction with specific primers.Results:The genotyping results showed that there were no differences in allelic (P = 0.114) and genotypic frequencies (P = 0.159) between the high caries and low caries groups.Conclusion:Future studies can be conducted in larger samples and different ethnicities around the globe to analyze the role played by SNPs of enamel formation genes in cariogenesis.

ENAM gene associated with T classification and inhibits proliferation in renal clear cell carcinoma.

The potential involvement of T classification-related genes in renal clear cell carcinoma (ccRCC) must be further explored. Public data were obtained from The Cancer Genome Atlas (TCGA) database. An overall survival (OS) predictive model was developed and validated (TCGA train, 5 years, AUC = 0.73, 3 years, AUC = 0.73, 1 year, AUC = 0.76; TCGA test, 5 years, AUC = 0.74, 3 years, AUC = 0.65, 1 year, AUC = 0.73; TCGA all, 5 years, AUC = 0.72, 3 years, AUC = 0.71, 1 year, AUC = 0.75). Finally, ENAM was selected for further analysis. In vitro experiment indicated that ENMA is downregulated in ccRCC, and its knockdown could promote proliferation in two cancer cell lines (OSRC-2 and SW839). Immune infiltration analysis revealed that ENAM could remarkably increase the content of cytotoxic cells, NK CD56 cells, NK cells and CD8+ T cells in the tumor immune microenvironment, which may be one reason for its tumor-inhibiting effect. In summary, ENAM may suppress cell proliferation in ccRCC and can be used as a potential reference value for the relief and immunotherapy of ccRCC.

Determination of mutation in the coding regions of FAM83H and ENAM genes in patients with imperfect enamel (Amelogenesis Imperfecta)

Introduction: Tooth enamel is a precious and highly mineralized tissue in the human body. Amelogenesis Imperfecta (AI) is a developmental, evolutionary and hereditary disease presents with the rare abnormal formation of enamel that affects the primary and secondary dentition. The molecular base of the incomplete quinizium together with clinical manifestation suggest that AI may result from mutations in the FAM83H and ENAM genes. In this study, we aimed to evalu- ate the association between Amelogenesis Imperfecta and mutations in the FAM83H and ENAM genes in 18 Iranian families with AI in dominant and non-syndromic form. Materials and Methods: 18 Iranian families with at least 1 patient with Amelogenesis Imperfecta were included in this case study and were examined for related specific manifestations and also, 10CC of blood was taken from each patient followed by PCR and genome sequence for genetic alterations in FAM83H and ENAM. Genome sequences were analyzed using CLC software and CLC Sequence Viewer was used to compare them with reference sequences in the RefSeq database at the NCBI later were discussed together with clinical manifestations for each patient. Results: All patients showed a mutation in the exon 5 of FAM83H gene in nucleotide rs56148058C/T which converted Serotonin to Aspartin. In two patients carried a mutation in the nucleotide rs546809055A/G that changed Leucine to Phenylalanine. None of patients showed sig- nificant alteration in the ENAM gene. Conclusion: This study indicates that FAM83H gene plays an import role in incidence of Amelogenesis Imperfecta in Iran.

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.

Ablation of Fam20c causes amelogenesis imperfecta via inhibiting Smad dependent BMP signaling pathway

BackgroundAmelogenesis imperfecta (AI) is a type of hereditary diseases that manifest defects in the formation or mineralization of enamel. Recently, it is reported that inactivation of FAM20C, a well-known Golgi casein kinase, caused AI. However, the mechanism of it is still unknown. The aim of this study was to explore the molecular mechanism of AI, which caused by ablation of FAM20C.ResultsIn the Sox2-Cre;Fam20Cfl/fl (cKO) mouse, we found abnormal differentiation of ameloblasts, improper formation and mineralization of enamel, and downregulation of both mRNA and protein level of enamel matrix proteins, including amelogenin (AMEL), ameloblastin (AMBN) and enamelin (ENAM). The levels of BMP2, BMP4 and BMP7, the ligands of BMP signaling pathway, and phosphorylation of Smad1/5/8, the key regulators of BMP signaling pathway, were all decreased in the enamel matrix and the ameloblast of the cKO mice, respectively. The expression of cyclin-dependent kinase inhibitor (P21), muscle segment homeobox genes 2 (Msx2), which are the target genes of the BMP signaling pathway, and laminin 3, the downstream factor of Msx2, were all significantly decreased in the ameloblasts of the cKO mice compared to the control mice.Conclusionthe results of our study suggest that ablation of FAM20C leads to AI through inhibiting the Smad dependent BMP signaling pathway in the process of amelogenesis.

Profiles of overall survival-related gene expression-based risk signature and their prognostic implications in clear cell renal cell carcinoma.

The present work aimed to evaluate the prognostic value of overall survival (OS)-related genes in clear cell renal cell carcinoma (ccRCC) and to develop a nomogram for clinical use. Transcriptome data from The Cancer Genome Atlas (TCGA) were collected to screen differentially expressed genes (DEGs) between ccRCC patients with OS > 5 years (149 patients) and those with <1 year (52 patients). In TCGA training set (265 patients), seven DEGs (cytochrome P450 family 3 subfamily A member 7 (CYP3A7), contactin-associated protein family member 5 (CNTNAP5), adenylate cyclase 2 (ADCY2), TOX high mobility group box family member 3 (TOX3), plasminogen (PLG), enamelin (ENAM), and collagen type VII α 1 chain (COL7A1)) were further selected to build a prognostic risk signature by the least absolute shrinkage and selection operator (LASSO) Cox regression model. Survival analysis confirmed that the OS in the high-risk group was dramatically shorter than their low-risk counterparts. Next, univariate and multivariate Cox regression revealed the seven genes-based risk score, age, and Tumor, lymph Node, and Metastasis staging system (TNM) stage were independent prognostic factors to OS, based on which a novel nomogram was constructed and validated in both TCGA validation set (265 patients) and the International Cancer Genome Consortium cohort (ICGC, 84 patients). A decent predictive performance of the nomogram was observed, the C-indices and corresponding 95% confidence intervals of TCGA training set, validation set, and ICGC cohort were 0.78 (0.74–0.82), 0.75 (0.70–0.80), and 0.70 (0.60–0.80), respectively. Moreover, the calibration plots of 3- and 5 years survival probability indicated favorable curve-fitting performance in the above three groups. In conclusion, the proposed seven genes signature-based nomogram is a promising and robust tool for predicting the OS of ccRCC, which may help tailor individualized therapeutic strategies.

Dataset on amelogenesis-related genes variants (ENAM and ENAM interacting genes) and on human leukocyte antigen alleles (DQ2 and DQ8) distribution in children with and without molar-incisor hypomineralisation (MIH).

All children, who were born in 2004 and had undergone surgical treatment for recurrent acute tonsillitis and/or acute otitis media at the ear, nose and throat clinic (ENT) between 2004 and 2010, were called on dental examination and blood sampling. Out of 441 invitees, 113 children and their parents/legal guardians agreed to participate. The following data from this group of subjects are presented: the presence of clinical signs of molar–incisor hypomineralisation (MIH), the distribution of human leukocyte antigen (HLA) alleles DQ2 and DQ8 and eight single nucleotide polymorphisms (SNPs) located in amelogenesis-related genes (rs3796704 in the ENAM gene, rs546778141 in the AMBN gene, rs2106416 in the AMELX gene, rs7660807 and rs35286445 in the AMTN gene, rs4870723 in the COL14A1 gene, rs2245803 in the MMP20 gene, and rs3828054 in the TUFT1 gene).Data on clinical signs of MIH were collected in accordance with the recommendation and on the proposed MIH clinical data recording sheet [1], and with appropriate preliminary training and calibration. Data on HLA DQ2 and DQ8 haplotypes and on SNPs of amelogenesis-related genes were obtained using DNA isolated from blood samples taken from subjects. The HLA DQ2 and DQ8 alleles were determined using the EliGene® Coeliac RT Kits (90,048-RT; Elisabeth Pharmacon spol. s.r.o., Brno-Židenice, Czech Republic) on a 7500 Fast RT-PCR System (Applied Biosystems, Waltham, MA, USA). The distributions of SNPs in the amelogenesis-related genes were determined using high resolution melting (HRM) using the Type-IT HRM Master Mix (Qiagen), TaqMan genotyping assays (ID: C__25766207_10; Thermo Fisher Scientific, Waltham, MA, USA) with the TaqMan Universal Master Mix II, or Sanger sequencing using sequencing master mix BigDye® Terminator v3.1 (Applied Biosystems) and ABI 3500 Genetic Analyser (Applied Biosystems).L. Hočevar, J. Kovač, K. Trebušak Podkrajšek, S. Battelino, A. Pavlič, 2020. The possible influence of genetic aetiological factors on molar–incisor hypomineralisation, Arch. Oral. Biol. 118, 104848. https://doi.org/10.1016/j.archoralbio.2020.104848.

Mitochondrial Function in Enamel Development.

Enamel is the most calcified tissue in vertebrates. Enamel formation and mineralization is a two-step process that is mediated by ameloblast cells during their secretory and maturation stages. In these two stages, ameloblasts are characterized by different morphology and function, which is fundamental for proper mineral growth in the extracellular space. Ultrastructural studies have shown that the mitochondria in these cells localize to different subcellular regions in both stages. However, limited knowledge is available on the role/s of mitochondria in enamel formation. To address this issue, we analyzed mitochondrial biogenesis and respiration, as well as the redox status of rat primary enamel cells isolated from the secretory and maturation stages. We show that maturation stage cells have an increased expression of PGC1α, a marker of mitochondrial biogenesis, and of components of the electron transport chain. Oxygen consumption rate (OCR), a proxy for mitochondrial function, showed a significant increase in oxidative phosphorylation during the maturation stage, promoting ATP production. The GSH/GSSG ratio was lower in the maturation stage, indicative of increased oxidation. Because higher oxidative phosphorylation can lead to higher ROS production, we tested if ROS affected the expression of AmelX and Enam genes that are essential for enamel formation. The ameloblast cell line LS8 treated with H2O2 to promote ROS elicited significant expression changes in AmelX and Enam. Our data highlight important metabolic and physiological differences across the two enamel stages, with higher ATP levels in the maturation stage indicative of a higher energy demand. Besides these metabolic shifts, it is likely that the enhanced ETC function results in ROS-mediated transcriptional changes.

ASSOCIATION OF ENAM C2452T POLYMORPHISM WITH HIGH RATES OF CARIES OCCURRENCE IN AN INDONESIAN POPULATION

Objective: Tooth decay or the caries process is a common dental problem that affects millions of people worldwide. Many risk factors are modifiable,while others are not (e.g., genetic factors). Polymorphism of the enamelin (ENAM) gene, which is required to ensure production of an essentialprotein for enamel development, may pose as a risk factor for the caries process. This study sought to investigate the possibility of ENAM C2452Tpolymorphism acting as a risk factor in the caries process.Methods: The polymerase chain reaction–restriction fragment length polymorphism method was employed to evaluate DNA samples taken from 95subjects with a high caries prevalence and 89 control subjects for ENAM C2452T polymorphism.Results: Based on Chi-squared tests, there were significant genotype and allele distribution differences between the group with a high cariesprevalence and the control group (p=0.005 and p=0.007). Polymorphism in this context may, therefore, serve as a risk factor for caries onset andprogression (OR: 3.62).Conclusion: ENAM C2452T polymorphism is related to the caries process and may constitute a risk factor.