Candidate genes for obstructive sleep apnea in non-syndromic children with craniofacial dysmorphisms - a narrative review.

Pediatric obstructive sleep apnea (POSA) is a complex disease with multifactorial etiopathogenesis. The presence of craniofacial dysmorphisms influencing the patency of the upper airway is considered a risk factor for POSA development. The craniofacial features associated with sleep-related breathing disorders (SRBD) - craniosynostosis, retrognathia and micrognathia, midface and maxillary hypoplasia - have high heritability and, in a less severe form, could be also found in non-syndromic children suffering from POSA. As genetic factors play a role in both POSA and craniofacial dysmorphisms, we hypothesize that some genes associated with specific craniofacial features that are involved in the development of the orofacial area may be also considered candidate genes for POSA. The genetic background of POSA in children is less explored than in adults; so far, only one genome-wide association study for POSA has been conducted; however, children with craniofacial disorders were excluded from that study. In this narrative review, we discuss syndromes that are commonly associated with severe craniofacial dysmorphisms and a high prevalence of sleep-related breathing disorders (SRBD), including POSA. We also summarized information about their genetic background and based on this, proposed 30 candidate genes for POSA affecting craniofacial development that may play a role in children with syndromes, and identified seven of these genes that were previously associated with craniofacial features risky for POSA development in non-syndromic children. The evidence-based approach supports the proposition that variants of these candidate genes could lead to POSA phenotype even in these children, and, thus, should be considered in future research in the general pediatric population.

Primary cilia and hypoxia-associated signaling in developmental odontogenic cysts in relation to autosomal dominant polycystic kidney disease - A novel insight.

Developmental cysts are pathological epithelial-lined cavities arising in various organs as a result of systemic or hereditary diseases. Molecular mechanisms involved in the formation of developmental odontogenic cysts (OCs) are not fully understood yet; the cystogenesis of renal cysts originating from the autosomal dominant polycystic kidney disease (ADPKD) has been, however, explored in much greater detail. This narrative review aimed i) to summarize molecular and cellular processes involved in the formation and growth of developmental OCs, especially dentigerous cysts (DCs) and odontogenic keratocysts (OKCs), ii) to find if there are any similarities in their cystogenesis to ADPKD cysts, and, based on that, iii) to suggest potential factors, candidate molecules, and mechanisms that could be involved in the DC formation, thus proposing further research directions. Here we suggest a possible association of developmental OCs with primary cilia disruption and with hypoxia, which have been previously linked with cyst formation in ADPKD patients. This is illustrated on the imagery of tissues from an ADPKD patient (renal cyst) and from developmental OCs, supporting the similarities in cell proliferation, apoptosis, and primary cilia distribution in DC/OKC/ADPKD tissues. Based on all that, we propose a novel hypothesis of OCs formation suggesting a crucial role of mutations associated with the signaling pathways of primary cilia (in particular, Sonic Hedgehog). These can lead to excessive proliferation and formation of cell agglomerates, which is followed by hypoxia-driven apoptosis in the centers of such agglomerates (controlled by molecules such as Hypoxia-inducible factor-1 alpha), leading to cavity formation and, finally, the OCs development. Based on this, we propose future perspectives in the investigation of OC pathogenesis.

Polymorphisms in genes expressed during amelogenesis and their association with dental caries: a case-control study.

OBJECTIVES: Dental caries is a widespread multifactorial disease, caused by the demineralization of hard dental tissues. Susceptibility to dental caries is partially genetically conditioned; this study was aimed at finding an association of selected single nucleotide polymorphisms (SNPs) in genes encoding proteins involved in amelogenesis with this disease in children. MATERIALS AND METHODS: In this case-control study, 15 SNPs in ALOX15, AMBN, AMELX, KLK4, TFIP11, and TUFT1 genes were analyzed in 150 children with primary dentition and 611 children with permanent teeth with/without dental caries from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) cohort. RESULTS: Dental caries in primary dentition was associated with SNPs in AMELX (rs17878486) and KLK4 (rs198968, rs2242670), and dental caries in permanent dentition with SNPs in AMELX (rs17878486) and KLK4 (rs2235091, rs2242670, rs2978642), (p ≤ 0.05). No significant differences between cases and controls were observed in the allele or genotype frequencies of any of the selected SNPs in ALOX15, AMBN, TFIP11, and TUFT1 genes (p > 0.05). Some KLK4 haplotypes were associated with dental caries in permanent dentition (p ≤ 0.05). CONCLUSIONS: Based on this study, we found that although the SNPs in AMELX and KLK4 are localized in intronic regions and their functional significance has not yet been determined, they are associated with susceptibility to dental caries in children. CLINICAL RELEVANCE: AMELX and KLK4 variants could be considered in the risk assessment of dental caries, especially in permanent dentition, in the European Caucasian population.

Lack of Association between Epidermal Growth Factor or Its Receptor and Reflux Esophagitis, Barrett's Esophagus, and Esophageal Adenocarcinoma: A Case-Control Study.

The epidermal growth factor (EGF) and its receptor (EGFR) gene-gene interactions were shown to increase the susceptibility to esophageal cancer. However, the role of the EGF/EGFR pathway in the development of gastroesophageal reflux disease (GERD) and its complications (reflux esophagitis (RE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC)) remains unclear. This association study is aimed at investigating functional EGF and EGFR gene polymorphisms, their mRNA expression in esophageal tissues, and EGF plasma levels in relation to RE, BE, and EAC development in the Central European population. 301 patients with RE/BE/EAC (cases) as well as 98 patients with nonerosive reflux disease (NERD) and 8 healthy individuals (controls) were genotyped for +61 A>G EGF (rs4444903) and +142285 G>A EGFR (rs2227983) polymorphisms using the TaqMan quantitative polymerase chain reaction (qPCR). In random subgroups, the EGF and EGFR mRNA expressions were analyzed by reverse transcription qPCR in esophageal tissue with and without endoscopically visible pathological changes; and the EGF plasma levels were determined by enzyme-linked immunosorbent assay. None of the genotyped SNPs nor EGF-EGFR genotype interactions were associated with RE, BE, or EAC development (p > 0.05). Moreover, mRNA expression of neither EGF nor EGFR differed between samples of the esophageal tissue with and without endoscopically visible pathology (p > 0.05) nor between samples from patients with different diagnoses, i.e., RE, BE, or EAC (p > 0.05). Nevertheless, the lower EGF mRNA expression in carriers of combined genotypes AA +61 EGF (rs4444903) and GG +142285 EGFR (rs2227983; p < 0.05) suggests a possible direct/indirect effect of EGF-EGFR gene interactions on EGF gene expression. In conclusion, EGF and EGFR gene variants and their mRNA/protein expression were not associated with RE, BE or EAC development in the Central European population.

Candida species and selected behavioral factors co-associated with severe early childhood caries: Case-control study.

Severe Early Childhood Caries (sECC) is a multifactorial disease associated with the occurrence of specific oral microorganisms and other environmental, behavioral, and genetic factors. This study aimed to construct a multivariable model including the occurrence of Candida spp. and selected behavioral factors (length of breastfeeding, serving sweet beverages and beginning of brushing child's teeth) to determine their relationships to the occurrence of sECC. In this case-control study 164 children with sECC and 147 children without dental caries were included. MALDI-TOF MS and multiplex qPCR were used to identify Candida spp. and selected bacteria in dental plaque samples, respectively. A questionnaire on oral hygiene, diet, and children's health was filled in by the parents. The constructed multivariable logistic regression model showed an independent influence of the microbial and behavioral factors in sECC etiopathogenesis. The occurrence of C. albicans and C. dubliniensis was associated with higher odds of sECC development (odds ratio, OR: 9.62 and 16.93, respectively), together with breastfeeding of 6 months or less (OR: 2.71), exposure to sweet beverages (OR: 3.77), and starting to brush child's teeth after the 12th month of age (OR: 4.10), all statistically significant (p < 0.01). Considering the high occurrence of C. albicans and C. dubliniensis in dental plaque in children with sECC, we propose them as "keystone pathogens" and risk factors for sECC. The models showed that presence of specific species of Candida in dental plaque may be a better descriptor of sECC than the mentioned behavioral factors.

CYP2C19 Gene Profiling as a Tool for Personalized Stress Ulcer Prophylaxis With Proton Pump Inhibitors in Critically Ill Patients - Recommendations Proposal.

To this date, there are no recommendations for personalized stress ulcer prophylaxis (SUP) in critical care that would take the patient's individual genetic predispositions into account. Of drugs used for this purpose, proton pump inhibitors (PPIs) are the first-choice drugs in intensive care unit patients. The degradation of proton pump inhibitors is mediated by cytochrome P450 (CYP) enzymes; in particular, CYP2C19 and, to a lesser extent, CYP3A4 are involved. Expression and metabolic activity of, namely in, CYP2C19 is significantly affected by single nucleotide polymorphisms, the drug metabolization rate varies greatly from ultrarapid to poor and likely influences the optimal dosage. As these CYP2C19 predictive phenotypes via CYP2C19 haplogenotypes (rs12248560/rs4244285) can be relatively easily determined using the current standard equipment of hospital laboratories, we prepared a set of recommendations for personalized PPI-based stress ulcer prophylaxis taking into account the patient's CYP2C19 predictive phenotype determined in this way. These recommendations are valid, in particular, for European, American and African populations, because these populations have the high representations of the CYP2C19*17 allele associated with the overexpression of the CYP2C19 gene and ultrarapid degradation of PPIs. We propose the CYP2C19 gene profiling as a tool for personalized SUP with PPI in critically ill patients.

Alteration of primary cilia morphology and associated signalling in ameloblastoma.

OBJECTIVES: Primary cilium is a cellular organelle with growing significance confirmed in tumour biology. Primary cilia have been associated with fine tuning of numerous cell signalling pathways and the role of this structure in cancer initiation and progression is recently at the forefront of attention. Here, we investigated possible alterations in the occurrence of primary cilia and changes of associated signalling in ameloblastoma, which represents the most common odontogenic tumour. METHODS: We performed immunohistochemistry to assess the number and morphology of primary cilia in ameloblastoma tissues. The gene expression of key SHH pathway members was analysed by qPCR. As a functional experiment, we treated a primary ameloblastoma cell line by a SHH pathway inhibitor Sonidegib (LDE225). RESULTS: We uncovered differences in primary cilia distribution and appearance in histological subtypes of ameloblastoma with the highest number of ciliated cells in plexiform and follicular subtypes. SHH protein was located close to primary cilia in ameloblastoma epithelial cells and the expression of molecules downstream of SHH signalling was upregulated. Moreover, the inhibition of SHH pathway by Sonidegib caused downregulation of SHH effector gene GLI1 and cell cycle regulator CCND1 in ameloblastoma primary cell line. The inhibition of SHH signalling also altered the expression of molecules involved in intraflagellar transport. CONCLUSIONS: In conclusion, our study uncovered alterations in number of ciliated cells and associated signalling in ameloblastoma, which indicate SHH inhibitors as potential therapeutic target to treat this disease.

The Role of the Oral Microbiota in the Etiopathogenesis of Oral Squamous Cell Carcinoma.

Dysbiosis in the oral environment may play a role in the etiopathogenesis of oral squamous cell carcinoma (OSCC). This review aims to summarize the current knowledge about the association of oral microbiota with OSCC and to describe possible etiopathogenetic mechanisms involved in processes of OSCC development and progression. Association studies included in this review were designed as case-control/case studies, analyzing the bacteriome, mycobiome, and virome from saliva, oral rinses, oral mucosal swabs, or oral mucosal tissue samples (deep and superficial) and comparing the results in healthy individuals to those with OSCC and/or with premalignant lesions. Changes in relative abundances of specific bacteria (e.g., Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus sp.) and fungi (especially Candida sp.) were associated with OSCC. Viruses can also play a role; while the results of studies investigating the role of human papillomavirus in OSCC development are controversial, Epstein-Barr virus was positively correlated with OSCC. The oral microbiota has been linked to tumorigenesis through a variety of mechanisms, including the stimulation of cell proliferation, tumor invasiveness, angiogenesis, inhibition of cell apoptosis, induction of chronic inflammation, or production of oncometabolites. We also advocate for the necessity of performing a complex analysis of the microbiome in further studies and of standardizing the sampling procedures by establishing guidelines to support future meta-analyses.

A SNaPshot Assay for Determination of the Mannose-Binding Lectin Gene Variants and an Algorithm for Calculation of Haplogenotype Combinations.

Mannose-binding lectin (MBL) deficiency caused by the variability in the MBL2 gene is responsible for the susceptibility to and severity of various infectious and autoimmune diseases. A combination of six single nucleotide polymorphisms (SNPs) has a major impact on MBL levels in circulation. The aim of this study is to design and validate a sensitive and economical method for determining MBL2 haplogenotypes. The SNaPshot assay is designed and optimized to genotype six SNPs (rs1800451, rs1800450, rs5030737, rs7095891, rs7096206, rs11003125) and is validated by comparing results with Sanger sequencing. Additionally, an algorithm for online calculation of haplogenotype combinations from the determined genotypes is developed. Three hundred and twenty-eight DNA samples from healthy individuals from the Czech population are genotyped. Minor allele frequencies (MAFs) in the Czech population are in accordance with those present in the European population. The SNaPshot assay for MBL2 genotyping is a high-throughput, cost-effective technique that can be used in further genetic-association studies or in clinical practice. Moreover, a freely available online application for the calculation of haplogenotypes from SNPs is developed within the scope of this project.

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.

HPV, protein p16 and squamous cell carcinoma of the oral cavity.

BACKGROUND: Squamous cell carcinoma of the oral cavity is generally caused by the long-term impact of known risk factors, e.g. tobacco and alcohol, along with chronic traumatisation. A number of studies now implicate HPV infection in head and neck tumour carcinogenesis but the exact role of HPV infection in the oral cavity remains unclear. METHODS: In this study, we evaluated 78 patients with oral squamous cell carcinoma (OSCC) for the expression of protein p16 in the context of HPV positivity and its influence on the overall survival rate, disease location, staging and grading. RESULTS: Regarding the tumour location, no significant difference was found between HPV-positive and HPV-negative patients, nor between p16-positive and p16-negative patients. There was also no trend in terms of HPV status and stage, and differentiation of carcinoma. There was no effect on HPV-positive patients relative to the time to progression (P=0.84) and overall survival rate (P=0.78). P16 positivity was not found to have an effect on the overall survival rate of patients (P=0.41) and there was no correlation between p16 positivity relative to the time to progression (P=0.66). CONCLUSIONS: In summary, the data suggest that there is no effect of HPV status on the prognosis of OSCC patients compared to other HNSCC locations.

Buccal films as a dressing for the treatment of aphthous lesions.

BACKGROUND: Buccal flexible films in the form of solid, thin, mucoadhesive patches can be used as dressings separating aphthous lesions from the environment of the oral cavity, which can in turn shorten the treatment period and reduce the pain perception. METHODS: The clinical study was performed on 36 volunteers suffering from aphthous lesions. The first group was treated using standard means-by application of an oral gel containing cholin salicylate (Mundisal) on the aphthous lesion. The second group was treated with the same preparation; however, the lesion was covered with a mucoadhesive film following the application of the gel. The criteria for statistical evaluation were the size of lesions in relation to the length of the treatment and the subjective perception of the treatment results. RESULTS AND CONCLUSIONS: The application of buccal films covering aphthous lesions during the treatment significantly increased the rate of healing when compared with the standard methods of treatment. While the pain improvement was statistically significant as soon as Day 3 in the experimental group, it was only apparent on Day 5 in the control group, and the number of successfully treated patients (pain perception improving to visual analogue scale 2 or less) was at all time points higher in the experimental group than in the control group. The results imply that the use of buccal films for treatment of aphthous lesions is very promising and can lead to a significant reduction in the duration of patients' discomfort.

A porcine model: surgical anatomy of the orbit for maxillofacial surgery.

Due to its similarity to humans, the pig has proven to be a suitable biomodel for both research purposes and for training medical professionals, particularly in surgical specializations. For example, new implant materials have been tested on pig jaws and pigs have also been used in the development of new surgical techniques. For optimizing the effectiveness of such research or training, detailed data on the anatomy of their particular features are needed. At present, however, only limited information related to surgical and imaging anatomy of the facial and orbital areas of the pig and its comparison to human structures from the experimental surgery point of view is available in the literature. The aim of this study was to obtain such data and to compare the morphological structures of the porcine and human orbital regions and to lay down the foundation for practical use in experimental surgery. Ten pig heads were examined using computed tomography (CT) and magnetic resonance imaging (MRI) and, subsequently, a dissection of the orbit was carried out. Attention was focused on the structure of the orbit (floor, rim and nerves) frequently affected by pathological processes in humans (such as trauma, infection or tumours) and which consequently are frequently the subject of maxillofacial surgery. The porcine orbit is suitable for use in experimental medicine. However, if used in experiments, its anatomical peculiarities must be taken into consideration. Our study presents a foundation of basic knowledge for researchers who plan to use the pig as a biomedical model to investigate alternative treatments in the head region.

Determination of dependencies among in vitro and in vivo properties of prepared mucoadhesive buccal films using multivariate data analysis.

Mucoadhesive films represent the most developed medical form of buccal application. Despite the intense focus on buccal film-based systems, there are no standardized methods for their evaluation, which limits the possibility of comparison of obtained data and evaluation of the significance of influence of formulation and process variables on properties of resulting films. The used principal component analysis, together with a partial least squares regression provided a unique insight into the effects of in vitro parameters of mucoadhesive buccal films on their in vivo properties and into interdependencies among the studied variables. In the present study eight various mucoadhesive buccal films based on mucoadhesive polymers (carmellose, polyethylene oxide) were prepared using a solvent casting method or a method of impregnation, respectively. An ethylcellulose or hydrophobic blend of white beeswax and white petrolatum were used as a backing layer. The addition of polyethylene oxide prolonged the in vivo film residence time (from 53.24±5.38-74.18±5.13 min to 71.05±3.15-98.12±1.75 min), and even more when combined with an ethylcellulose backing layer (98.12±1.75 min) and also improved the film's appearance. Tested non-woven textile shortened the in vivo film residence time (from 74.18±5.13-98.12±1.75 min to 53.24±5.38-81.00±8.47 min) and generally worsened the film's appearance. Mucoadhesive buccal films with a hydrophobic backing layer were associated with increased frequency of adverse effects.

Mucoadhesive films as perspective oral dosage form.

UNLABELLED: Mucoadhesion is a specific phenomenon of creating bonds during intimate contact between biological surfaces covered by a mucus layer and a mucoadhesive material. In recent years come to the forefront of interest in the pharmaceutical industry modern dosage forms based on this specific process. Films (discs, patches) composed of mucoadhesive polymers (cellulose derivatives, polyacrylates, polyoxyethylene, etc.) prepared by established methods (solvent casting, hot melt extrusion, etc.) could be perspective candidates for oral administration of many drugs due to their flexibility and comfortable use. In addition, they can circumvent the relatively short residence time of conventional oral dosage forms on the mucosa and provide a precisely measured drug dose to the application site. Moreover, they can also help to protect the wound surface, thus help to reduce pain and improve effectiveness of the therapy. The aim of this article is to give an overview about the principles of creation of mucoadhesive bonds and about novel dosage form - mucoadhesive films in terms of their composition, preparation and practical usage. KEYWORDS: oral mucosa mucoadhesion principles mucoadhesive dosage forms films patches discs.

Oral mucosa and therapy of recurrent aphthous stomatitis.

UNLABELLED: Oral mucosa is one of the specific surfaces of the human body, which is permanently exposed to external factors related with food intake, breathing and speaking processes, which can lead to the onset of some problems. Disorders of the oral mucosa are a group of diseases, affecting, in the course of life, the majority of the population. Many of the oral mucosa ailments are manifested by lesions. Recurrent aphthous stomatitis (RAS) is the most common of these diseases. Despite much clinical and research attention, its causes remain poorly understood and treatment is only symptomatic. RAS is reported to affect up to 25% of the population worldwide. Topical or systemic therapy (corticosteroids, antiseptics, anti-inflamatory drugs, immunomodulating agents, etc.) can be used for treatment of RAS-associated symptoms. In general, topical therapy should be preferred due to the smaller drug load of the organism. In both cases, the active substance has to be in suitable dosage form. Recently, besides the conventional ways of application (rinses), the main disadvantage of which is the short time of resistance in the oral cavity, mucoadhesive dosage forms are used. The aim of this article is to give a theoretical overview of the oral mucosa topic and its most frequent disease - recurrent aphthous stomatitis in terms of various types of the disease classification, diagnosis and therapy, and in terms of the usage of various types of active substances and medical forms. KEYWORDS: oral mucosa recurrent aphthous stomatitis therapy mucoadhesive dosage forms.