scholarly journals Elevation of hepatic sulphotransferase activities in mice with resistance to cystic fibrosis

2002 ◽  
Vol 364 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Josie L. FALANY ◽  
Heather GREER ◽  
Timea KOVACS ◽  
Eric J. SORSCHER ◽  
Charles N. FALANY
Keyword(s):  
Cystic Fibrosis ◽  
Mouse Liver ◽  
Northern Blot Analysis ◽  
Transmembrane Conductance Regulator ◽  
Male Mice ◽  
Transmembrane Conductance ◽  
Female Adult ◽  
Cf Transmembrane Conductance Regulator ◽  
Different Levels

The severity of intestinal disease in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) (-/−) mice has been reported to co-segregate with gene loci which contain the genes for hydroxysteroid sulphotransferase (SULT). Because of the potential involvement of steroid hormones in CF, we investigated levels of steroid SULT activity in the livers of CFTR mice to determine whether the levels of SULT activity correlate with the occurrence or severity of CF. To elucidate the possible role of SULT activity in ameliorating the deleterious effects of CF in CFTR (-/−) mice, we determined the levels of phenol SULT (PST), hydroxysteroid SULT [dehydroepiandrosterone (DHEA)-ST] and oestrogen SULT (EST) activity in control CFTR (+/+), heterozygous CFTR (+/−) and homozygous CFTR (-/−) mice, which survive to adulthood. The level of PST activity was not significantly different between any of the groups of mice, regardless of sex or genotype. Although DHEA-ST activity was significantly higher in female mice than in male mice, there was no difference in DHEA-ST activity that could be correlated with genotype. In contrast with PST and DHEA-ST activities, we found that some male and all female adult CFTR (-/−) mice had elevated, dramatically different levels of EST from both CFTR (+/+) and CFTR (+/−) mice. Results from these SULT activity experiments were confirmed by Northern-blot analysis of mouse-liver RNA. Subsequent studies with preweanling mice revealed no differences in the levels of EST that could be correlated with genotype. Thus this study indicates that EST is elevated significantly in CFTR (-/−) mice which survive to adulthood and provides important biochemical information that EST levels may be protective in CF.

scholarly journals Intestinal mucins from cystic fibrosis mice show increased fucosylation due to an induced Fucα1-2 glycosyltransferase

2002 ◽  
Vol 367 (3) ◽  
pp. 609-616 ◽  
Author(s):  
Kristina A. THOMSSON ◽  
Marina HINOJOSA-KURTZBERG ◽  
Karin A. AXELSSON ◽  
Steven E. DOMINO ◽  
John B. LOWE ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Small Intestine ◽  
Blood Group ◽  
Northern Blot Analysis ◽  
Fold Increase ◽  
Transmembrane Conductance Regulator ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
Cf Transmembrane Conductance Regulator ◽  
Blood Group H

In gene-targeted mouse models for cystic fibrosis (CF), the disease is mainly manifested by mucus obstruction in the intestine. To explore the mucus composition, mucins insoluble and soluble in 6M guanidinium chloride were purified by three rounds of isopycnic ultracentrifugation from the small and large intestines of CF mice (Cftrm1UNC/Cftrm1UNC) and compared with wild-type mice. The amino acid composition was typical of that for mucins and showed increased amounts of the insoluble (2.5-fold increase) and soluble (7-fold increase) mucins in the small intestine of the CF mice compared with wild-type mice. Mucins from the large intestine of both wild-type and CF mice showed a high but constant level of fucosylation. In contrast, the insoluble and soluble mucins of the small intestine in CF mice revealed a large increase in fucose, whereas those of wild-type mice contained only small amounts of fucose. This increased fucosylation was analysed by releasing the O-linked oligosaccharides followed by GC-MS. NMR spectroscopy revealed that the increased fucosylation was due to an increased expression of blood group H epitopes (Fucα1-2Gal-). Northern-blot analysis, using a probe for the murine Fucα1-2 fucosyltransferase (Fut2), showed an up-regulation of this mRNA in the small intestine of the CF mice, suggesting that this enzyme is responsible for the observed increase in blood group H-type glycosylation. The reason for this up-regulation could be a direct or indirect effect of a non-functional CF transmembrane conductance regulator (CFTR) caused by the absence of CFTR channel.

scholarly journals Pseudomonas aeruginosa Consumption of Airway Metabolites Promotes Lung Infection

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 957
Author(s):  
Sebastián A. Riquelme ◽  
Alice Prince
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Chronic Disease ◽  
Lung Infection ◽  
Bacterial Disease ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Cf Transmembrane Conductance Regulator ◽  
Multiple Pathogens

Prevailing dogma indicates that the lung of cystic fibrosis (CF) individuals is infected by multiple pathogens due to the abundant accumulation of mucus, which traps most of inhaled organisms. However, this hypothesis does not explain how specific opportunists, like Pseudomonas aeruginosa, are selected in the CF lung to cause chronic disease. This strongly suggests that other factors than mucus are accrued in the human airway and might predispose to bacterial disease, especially by P. aeruginosa. In this review we discuss the role of macrophage metabolites, like succinate and itaconate, in P. aeruginosa pneumonia. We analyze how dysfunction of the CF transmembrane conductance regulator (CFTR) favors release of these metabolites into the infected airway, and how P. aeruginosa exploits these elements to induce transcriptomic and metabolic changes that increase its capacity to cause intractable disease. We describe the host and pathogen pathways associated with succinate and itaconate catabolism, mechanisms of bacterial adaptation to these determinants, and suggest how both experimental settings and future therapies should consider macrophage metabolites abundance to better study P. aeruginosa pathogenesis.

II. Regulation of CFTR by small molecules including HCO 3 −

1998 ◽  
Vol 275 (6) ◽  
pp. G1221-G1226 ◽  
Author(s):  
Beate Illek ◽  
Horst Fischer ◽  
Terry E. Machen
Keyword(s):  
Cystic Fibrosis ◽  
Small Molecules ◽  
Protein Product ◽  
Mechanisms Of Action ◽  
Intestinal Cells ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Binding Domains ◽  
Cf Transmembrane Conductance Regulator

Cystic fibrosis (CF) affects a number of epithelial tissues, including those in the gastrointestinal tract. The goal of this review is to summarize data related to regulation of the protein product of the CF gene, CF transmembrane conductance regulator (CFTR), by a variety of small molecules. There has been a surge of interest in discovering small molecules that could be exogenously added to cells and tissues to regulate CFTR and could potentially be used alone or in combination with genetic approaches for therapy in CF. We will discuss the apparent mechanisms of action of genistein, milrinone, 8-cyclopentyl-1,3-dipropylxanthine, IBMX, and NS-004; several of which appear to interact directly with one or both nucleotide binding domains of CFTR. We also discuss how [Formula: see text]interacts with CFTR as both a permeating anion and a potential regulator of Cl−permeation through the CFTR ion channel. It is likely that there are complicated interactions between Cl−and[Formula: see text] in the secretion of both ions through the CFTR and the anion exchanger in intestinal cells, and these may yield a role of CFTR in regulation of intestinal[Formula: see text] secretion as well as of intra- and extracellular pH.

scholarly journals A Peptide Nucleic Acid (PNA) Masking the miR-145-5p Binding Site of the 3′UTR of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mRNA Enhances CFTR Expression in Calu-3 Cells

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1677 ◽  
Author(s):  
Shaiq Sultan ◽  
Andrea Rozzi ◽  
Jessica Gasparello ◽  
Alex Manicardi ◽  
Roberto Corradini ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Binding Site ◽  
Peptide Nucleic Acid ◽  
Therapeutic Strategy ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Treatment Protocols ◽  
Cftr Protein ◽  
Cystic Fibrosis Transmembrane ◽  
Different Levels

Peptide nucleic acids (PNAs) have been demonstrated to be very useful tools for gene regulation at different levels and with different mechanisms of action. In the last few years the use of PNAs for targeting microRNAs (anti-miRNA PNAs) has provided impressive advancements. In particular, targeting of microRNAs involved in the repression of the expression of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which is defective in cystic fibrosis (CF), is a key step in the development of new types of treatment protocols. In addition to the anti-miRNA therapeutic strategy, inhibition of miRNA functions can be reached by masking the miRNA binding sites present within the 3′UTR region of the target mRNAs. The objective of this study was to design a PNA masking the binding site of the microRNA miR-145-5p present within the 3′UTR of the CFTR mRNA and to determine its activity in inhibiting miR-145-5p function, with particular focus on the expression of both CFTR mRNA and CFTR protein in Calu-3 cells. The results obtained support the concept that the PNA masking the miR-145-5p binding site of the CFTR mRNA is able to interfere with miR-145-5p biological functions, leading to both an increase of CFTR mRNA and CFTR protein content.

scholarly journals ΔF508 CFTR Pool in the Endoplasmic Reticulum Is Increased by Calnexin Overexpression

2004 ◽  
Vol 15 (2) ◽  
pp. 563-574 ◽  
Author(s):  
Tsukasa Okiyoneda ◽  
Kazutsune Harada ◽  
Motohiro Takeya ◽  
Kaori Yamahira ◽  
Ikuo Wada ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Endoplasmic Reticulum ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Δf508 Cftr ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
Cystic Fibrosis Transmembrane ◽  
Erad Pathway

The most common cystic fibrosis transmembrane conductance regulator (CFTR) mutant in cystic fibrosis patients, ΔF508 CFTR, is retained in the endoplasmic reticulum (ER) and is consequently degraded by the ubiquitin-proteasome pathway known as ER-associated degradation (ERAD). Because the prolonged interaction of ΔF508 CFTR with calnexin, an ER chaperone, results in the ERAD of ΔF508 CFTR, calnexin seems to lead it to the ERAD pathway. However, the role of calnexin in the ERAD is controversial. In this study, we found that calnexin overexpression partially attenuated the ERAD of ΔF508 CFTR. We observed the formation of concentric membranous bodies in the ER upon calnexin overexpression and that the ΔF508 CFTR but not the wild-type CFTR was retained in the concentric membranous bodies. Furthermore, we observed that calnexin overexpression moderately inhibited the formation of aggresomes accumulating the ubiquitinated ΔF508 CFTR. These findings suggest that the overexpression of calnexin may be able to create a pool of ΔF508 CFTR in the ER.

Cloning and sequence analysis of rat cystic fibrosis transmembrane conductance regulator

1992 ◽  
Vol 262 (6) ◽  
pp. L779-L784 ◽  
Author(s):  
M. A. Fiedler ◽  
Z. K. Nemecz ◽  
G. E. Shull
Keyword(s):  
Cystic Fibrosis ◽  
Northern Blot Analysis ◽  
Polymerase Chain Reaction Amplification ◽  
Rat Colon ◽  
Predicted Amino Acid Sequence ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Reaction Amplification ◽  
Polymerase Chain ◽  
Cystic Fibrosis Transmembrane

A complementary DNA (cDNA) encoding the rat cystic fibrosis transmembrane conductance regulator (CFTR) has been isolated and the tissue distribution of the rat CFTR mRNA has been determined. Northern blot analysis revealed that the highest levels of the 6.3 kilobase (kb) CFTR mRNA were expressed in the colon, with expression also noted in uterus, lung, stomach, and small intestine. A 7.5-kb mRNA was expressed in skeletal muscle, and in testes both the 7.5-kb mRNA and a 6.0-kb mRNA were expressed. Five cDNAs were isolated from a rat colon library, the longest corresponding to codons 684 through the poly A tail. Three other clones, corresponding to codons 213 through 245, 372 through 574, and 656 through 886 were also isolated. Polymerase chain reaction amplification of cDNA prepared from rat colon mRNA was utilized to clone the remainder of the cDNA. The predicted amino acid sequence of the rat CFTR is 79% identical to the human CFTR, with 73% identity noted in the R domain, and 81 and 83% identities noted in nucleotide binding folds 1 and 2, respectively. Thirty-two of the 38 potential phosphorylation sites identified in the human CFTR were also present in the rat CFTR.

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