Complex analysis of multiple single nucleotide polymorphisms as putative risk factors of tooth agenesis in the Hungarian population.

OBJECTIVES: The role was studied of multiple single nucleotide polymorphisms in tooth agenesis in the Hungarian population using a complex approach. METHODS: Eight SNPs, PAX9 -912 C/T, PAX9 -1031 A/G, MSX1 3755 A/G, FGFR1 T/C rs881301, IRF6 T/C rs764093, AXIN2-8150 A/G, AXIN2-8434 A/G and AXIN2-30224 C/T, were studied in 192 hypodontia and 17 oligodontia cases and in 260 healthy volunteers. Case-control analysis was performed to test both allelic and genotypic associations as well as associations at the level of haplotypes. Multivariate exploratory Bayesian network-based multi-level analysis of relevance (BN-BMLA) as well as logistic regression analysis were performed. RESULTS: Conventional statistics showed that PAX9 SNP -912 C/T and the MSX1 SNP changed the incidence of hypodontia, although after Bonferroni correction for multiple hypothesis testing, the effects were only borderline tendencies. Using a statistical analysis better suited for handling multiple hypotheses, the BN-BMLA, PAX9 SNPs clearly showed a synergistic effect. This was confirmed by other multivariate analyses and it remained significant after corrections for multiple hypothesis testing (p < 0.0025). The PAX9-1031-A-PAX9-912-T haplotype was the most relevant combination causing hypodontia. Interaction was weaker between PAX9 and MSX1, while other SNPs had no joint effect on hypodontia. CONCLUSION: This complex analysis shows the important role of PAX9 and MSX1 SNPs and of their interactions in tooth agenesis, while IRF6, FGFR1 and AXIN2 SNPs had no detectable role in the Hungarian population. These results also reveal that risk factors in hypodontia need to be identified in various populations, since there is considerable variability among them.

[Treatment options of missing teeth resulting from hypodontia. Literature overview I]. / A hypodontia következtében létrejött foghiány ellátásának lehetôségei. Irodalmi áttekintés I.

Nowadays there is an increased need to identify genetic polimorphisms, the underlying genetic factors of hypodontia. This article aims to describe the genetic components of hypodontia, the most frequent congenital tooth development disorder, as well as its interdisciplinary treatment. Congenitally missing teeth may cause serious emotional and physical problems particularly during adolescence. To prevent this, the early diagnosis and the development of definitive treatment plan are vital. In this work the interdisciplinary management involving a dental team plays a crucial role. The most important first step in hypodontia management is to decide whether to apply space closure or space opening when making room for fixed restorations and implants.

[Treatment options of missing teeth resulting from hypodontia. Literature overview II]. / A hypodontia következtében létrejött foghiány ellátásának lehetoségei. Lrodalmi attekintés II.

Congenital hypodontia may cause serious emotional and physical problems which can become particularly grave during adolescence. This article highlights the importance of early diagnosis and the prevention of the progress of the state, and discusses a variety of definitive treatment plans. The aim of restorative dentistry is to restore function, improve appearance and prevent complications caused by hypodontia. When developing a treatment plan, first the severity of hypodontia, the number of missing teeth, and some other factors have to be considered. This can be followed by the treatment, which involves an interdisciplinary dental team.

[Isolating, culturing and characterizing stem cells of human dental pulp origin]. / Humán fogbél eredetu ossejtek izolálása, tenyésztése es jellemzése.

Evidence has been accumulating for the presence of stem cells in dental tissues. The authors' studies aimed to produce primary culture from human dental pulp. Furthermore, they wanted to identify clonogenic cells with progenitor properties in these cultures, and to characterize their proliferative capacity. The dental pulp was isolated from surgically removed wisdom teeth. The extracellular matrix was enzymatically degraded to obtain isolated cells for culturing. Identification of STRO-1 mesenchymal stem cell marker was achieved by immunocytochemistry. Osteogenic differentiation was detected by the application of Alizarin Red. The proliferative activity of the cell cultures in response to serum, EGF and BMP2 was estimated by MTT assay. The authors' most important finding is the successful establishment of stable primary cell culture from human dental pulp tissue. The cultures can be passaged multiple times and they contain clonogenic, STRO-1 immunopositive cells. Their mineralization capacity was shown by mineralized deposits as a result of induction by suitable medium. The presence of serum increased, while both EGF and BMP2 concentration-dependently decreased the cell proliferation in the cultures. The authors' model provides the foundation for studies of the proliferation and differentiation of dental pulp cells at molecular level, and opens a new direction towards the biological regeneration of dental tissues.

CFTR gene transfer to human cystic fibrosis pancreatic duct cells using a Sendai virus vector.

Cystic fibrosis (CF) is a fatal inherited disease caused by the absence or dysfunction of the CF transmembrane conductance regulator (CFTR) Cl- channel. About 70% of CF patients are exocrine pancreatic insufficient due to failure of the pancreatic ducts to secrete a HCO3- -rich fluid. Our aim in this study was to investigate the potential of a recombinant Sendai virus (SeV) vector to introduce normal CFTR into human CF pancreatic duct (CFPAC-1) cells, and to assess the effect of CFTR gene transfer on the key transporters involved in HCO3- transport. Using polarized cultures of homozygous F508del CFPAC-1 cells as a model for the human CF pancreatic ductal epithelium we showed that SeV was an efficient gene transfer agent when applied to the apical membrane. The presence of functional CFTR was confirmed using iodide efflux assay. CFTR expression had no effect on cell growth, monolayer integrity, and mRNA levels for key transporters in the duct cell (pNBC, AE2, NHE2, NHE3, DRA, and PAT-1), but did upregulate the activity of apical Cl-/HCO3- and Na+/H+ exchangers (NHEs). In CFTR-corrected cells, apical Cl-/HCO3- exchange activity was further enhanced by cAMP, a key feature exhibited by normal pancreatic duct cells. The cAMP stimulated Cl-/HCO3- exchange was inhibited by dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (H2-DIDS), but not by a specific CFTR inhibitor, CFTR(inh)-172. Our data show that SeV vector is a potential CFTR gene transfer agent for human pancreatic duct cells and that expression of CFTR in CF cells is associated with a restoration of Cl- and HCO3- transport at the apical membrane.

Gene polymorphisms in periodontitis and hypodontia: methodological basis of investigations.

An increasing number of evidence supports the assumption that genetic factors have crucial role in the development of periodontitis and hypodontia. The strategic purpose of the authors is to identify the genetic background of these disorders and to map the gene polymorphisms involved in their development. As a first step of an experimental series, we aimed to set and optimize multiple individual gene polymorphism identification methods by the combination of polymerase chain reaction and restriction fragment length polymorphism analysis methods. We have successfully optimized eight single nucleotide polymorphism procedures that are potentially involved in periodontitis (IL-1 alpha -889, IL-1 beta -511, IL-1 beta +3954, IL-6 -174, IL-10 -1082, TLR-4 -299, TLR-4 -399, TNF-alpha -308), and another two that might be related to the appearance of hypodontia (PAX9 -1032, PAX9 -912). Besides the dominant allele, we also observed the presence of the rare allele in each polymorphism although at present we have a small sample number. These preliminary studies provide evidence for the feasibility of further investigations with large sample numbers comparing control and patient groups. These studies may lead to the development of new diagnostic strategies and provide novel tools for the early recognition of genetic predisposition and the primary control of the diseases. Furthermore, they project future therapeutic avenues for gene therapy in the cure and prevention of oral disorders.

Vectorial bicarbonate transport by Capan-1 cells: a model for human pancreatic ductal secretion.

Human pancreatic ducts secrete a bicarbonate-rich fluid but our knowledge of the secretory process is based mainly on studies of animal models. Our aim was to determine whether the HCO(3)(-) transport mechanisms in a human ductal cell line are similar to those previously identified in guinea-pig pancreatic ducts. Intracellular pH was measured by microfluorometry in Capan-1 cell monolayers grown on permeable filters and loaded with BCECF. Epithelial polarization was assessed by immunolocalization of occludin. Expression of mRNA for key electrolyte transporters and receptors was evaluated by RT-PCR. Capan-1 cells grown on permeable supports formed confluent, polarized monolayers with well developed tight junctions. The recovery of pH(i) from an acid load, induced by a short NH(4)(+) pulse, was mediated by Na(+)-dependent transporters located exclusively at the basolateral membrane. One was independent of HCO(3)(-) and blocked by EIPA (probably NHE1) while the other was HCO(3)(-)-dependent and blocked by H(2)DIDS (probably pNBC1). Changes in pH(i) following blockade of basolateral HCO(3)(-) accumulation confirmed that the cells achieve vectorial HCO(3)(-) secretion. Dose-dependent increases in HCO(3)(-) secretion were observed in response to stimulation of both secretin and VPAC receptors. ATP and UTP applied to the apical membrane stimulated HCO(3)(-) secretion but were inhibitory when applied to the basolateral membrane. HCO(3)(-) secretion in guinea-pig ducts and Capan-1 cell monolayers share many common features, suggesting that the latter is an excellent model for studies of human pancreatic HCO(3)(-) secretion.