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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. [ABSTRACT FROM AUTHOR]

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, CFTRinh-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. J. Cell. Physiol. 214: 442–455, 2008. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

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 HCO3- 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 pHi from an acid load, induced by a short NH4+ pulse, was mediated by Na+-dependent transporters located exclusively at the basolateral membrane. One was independent of HCO3- and blocked by EIPA (probably NHE1) while the other was HCO3--dependent and blocked by H2DIDS (probably pNBC1). Changes in pHi following blockade of basolateral HCO3- accumulation confirmed that the cells achieve vectorial HCO3- secretion. Dose-dependent increases in HCO3- secretion were observed in response to stimulation of both secretin and VPAC receptors. ATP and UTP applied to the apical membrane stimulated HCO3- secretion but were inhibitory when applied to the basolateral membrane. HCO3- 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 HCO3- secretion. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]