BACKGROUND AND OBJECTIVES: Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel protein that plays an important role in electrolyte and water transport, whose kinetics and localization are altered in cystic fibrosis (CF). Previous studies showed its presence in the apical domain of ciliated respiratory epithelial cells, and airway secretory glands. The purpose of this study was to characterize the localization of CFTR in the epithelium of nasal polyp of the subjects without phenotypic expression of cystic fibrosis. MAERIALS AND METHODS: Immunohistochemical staining for CFTR, using monoclonal mouse anti-human CFTR, were performed on tissue sections of 4 normal turbinate and nasal polyps from 10 patients who underwent intranasal operation. RESULTS: The nasal polyp epithelium demonstrated a heterogeneous pattern of CFTR expressions, including diffuse or scattered cytoplasmic labeling, very low to undetectable labeling, intense perinuclear staining, and typical apical location. CONCLUSION: These results suggest that abnormal expression and distribution of the CFTR may have a role in the formation of nasal polyp.
Animals ; Chloride Channels ; Cystic Fibrosis Transmembrane Conductance Regulator* ; Cystic Fibrosis* ; Cytoplasm ; Epithelial Cells* ; Epithelium ; Humans ; Kinetics ; Mice ; Nasal Polyps* ; Turbinates

OBJECTIVETo focus on the asthmatic pathogenesis and clinical manifestations related to epithelial sodium channel (ENaC)/chlorine ion channel.

DATA SOURCESThe data analyzed in this review were the English articles from 1980 to 2015 from journal databases, primarily PubMed and Google Scholar. The terms used in the literature search were: (1) ENaCs; cystic fibrosis (CF) transmembrane conductance regulator (CFTR); asthma/asthmatic, (2) ENaC/sodium salt; CF; asthma/asthmatic, (3) CFTR/chlorine ion channels; asthma/asthmatic, (4) ENaC/sodium channel/scnn1a/scnn1b/scnn1g/scnn1d/amiloride-sensitive/amiloride-inhibtable sodium channels/sodium salt; asthma/asthmatic, lung/pulmonary/respiratory/tracheal/alveolar, and (5) CFTR; CF; asthma/asthmatic (ti).

STUDY SELECTIONThese studies included randomized controlled trials or studies covering asthma pathogenesis and clinical manifestations related to ENaC/chlorine ion channels within the last 25 years (from 1990 to 2015). The data involving chronic obstructive pulmonary disease and CF obtained from individual studies were also reviewed by the authors.

RESULTSAirway surface liquid dehydration can cause airway inflammation and obstruction. ENaC and CFTR are closely related to the airway mucociliary clearance. Ion transporters may play a critical role in pathogenesis of asthmatic exacerbations.

CONCLUSIONSIon channels have been the center of many studies aiming to understand asthmatic pathophysiological mechanisms or to identify therapeutic targets for better control of the disease.

Asthma ; physiopathology ; Chloride Channels ; physiology ; Cystic Fibrosis ; genetics ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; Epithelium ; physiopathology ; Humans ; Respiratory System ; physiopathology ; Sodium Channels ; physiology

BACKGROUND AND OBJECTIVES: Nucleotide binding to purinergic P2Y receptors contributes to the regulation of fluid and ion transport in the middle ear epithelial cells. Here, we investigated the regulatory mechanism of the P2Y2 receptor agonist, uridine-5'-triphosphate (UTP), on Cl- transport in cultured normal human middle ear epithelial (NHMEE) cells. MATERIALS AND METHOD: Electrophysiological measurements were performed in monolayers of cultured NHMEE cells. Short circuit currents (Isc) were measured from the cells mounted in Ussing chambers under various conditions. RESULTS: Apical addition of UTP in presence of amiloride evoked a transient rise and a sustained response in Isc due to Cl- efflux. Application of different Cl- channel blockers to the apical side of the cells significantly decreased UTP-induced Isc. Niflumic acid (NFA), a known blocker of Ca(2+)-activated chloride channels (CACC), and CFTRinh172, a selective inhibitor of cystic fibrosis transmembrane conductance regulator (CFTR), partially inhibited the UTP-induced Cl- secretion, respectively. CONCLUSION: Cl- transport across the airway epithelia plays a predominant role in regulating airway hydration. In this study, UTP is shown to increase both CACC and CFTR-dependent Cl- secretion in NHMEE cells, suggesting their role in fluid and ion transport in the middle ear epithelium.
Amiloride ; Chloride Channels ; Cystic Fibrosis ; Cystic Fibrosis Transmembrane Conductance Regulator ; Ear, Middle ; Epithelial Cells ; Epithelium ; Humans ; Ion Channels ; Ion Transport ; Niflumic Acid ; Receptors, Purinergic P2Y ; Uridine Triphosphate

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). These mutations alter the synthesis, processing, function, or half-life of CFTR, the main chloride channel expressed in the apical membrane of epithelial cells in the airway, intestine, pancreas, and reproductive tract. Lung disease is the most critical manifestation of CF. It is characterized by airway obstruction, infection, and inflammation that lead to fatal tissue destruction, which causes most CF morbidity and mortality. This article reviews the pathophysiology of CF, recent animal models, and current treatment of CF.
Airway Obstruction ; Chloride Channels ; Cystic Fibrosis Transmembrane Conductance Regulator ; Cystic Fibrosis ; Epithelial Cells ; Epithelial Sodium Channels ; Half-Life ; Inflammation ; Intestines ; Lung Diseases ; Lung ; Membranes ; Models, Animal ; Mortality ; Pancreas

Cystic fibrosis is the most common autosomal recessive disease in Caucasian. Cystic fibrosis is caused by cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations that lead to dysfunction of chloride ion channel regulations in the epithelium. Cystic fibrosis can affect multiple organ functions, resulting in various signs and symptoms. Typically, chronic airway infection, maldigestion, failure to thrive, and male infertility can occur. There are approximately 1800 CFTR gene mutations which have been identified thus far. However, there are only a few types of mutations reported in Korea because the prevalence of the disease is different among ethnicitiess and nations. Despite its rarity, reports of CFTR mutations or diagnosed patients on the rise. Therefore, we have to detect better outcomes as early as possible based on a precise understanding of the disease entity. We report a 9-year-old girl carrying D339Y and Q220X gene mutations, as the first case report of a D339Y mutation in Korea.
Child ; Chloride Channels ; Cystic Fibrosis ; Cystic Fibrosis Transmembrane Conductance Regulator ; Epithelium ; Failure to Thrive ; Humans ; Infertility, Male ; Korea ; Lifting ; Male ; Prevalence ; Social Control, Formal

BACKGROUND AND OBJECTIVES: Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel protein, its kinetics and localization are altered in cystic fibrosis. The purpose of this study was to evaluate whether the nasal polyp patients without phenotypic manifestation of cystic fibrosis have any form of CFTR mutations and to characterize the localization of CFTR in the nasal polyp. MATERIALS AND METHODS: The study group consisted of 71 subjects with nasal polyp who underwent an intranasal operation, and 20 normal subjects. Peripheral blood of the study groups were screened for mutation on the exon 3, 4, and 7 of the CFTR gene using single-stranded DNA conformational polymorphism (SSCP). Immunohistochemical staining for CFTR was conducted on the nasal polyps of studied subjects and normal turbinates as the control. RESULTS: While in the nasal polyp group, SSCP screening revealed two cases of mutant band on the exon 3, the normal control group did not show mutant band in all exons screened. CFTR showed the typical apical distribution in the normal turbinate mucosa, whereas in the nasal polyp, regardless of an abnormal band in exon 3, CFTR demonstrated a heterogenous pattern of localization consisting of cytoplasmic labeling, perinuclear staining, and intermingled apical location. CONCLUSION: These results suggest that an altered localization of the CFTR in the nasal polyps, based not only on the CFTR mutation but also on the acquired inflammatory process, may have an important role in the formation of nasal polyps.
Chloride Channels ; Cystic Fibrosis Transmembrane Conductance Regulator* ; Cystic Fibrosis* ; Cytoplasm ; DNA, Single-Stranded ; Exons ; Humans ; Immunohistochemistry ; Kinetics ; Mass Screening ; Mucous Membrane ; Nasal Polyps* ; Polymorphism, Single-Stranded Conformational ; Turbinates

Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) gene leads to cystic fibrosis, an autosomal recessive genetic disorder affecting a number of organs including the lung airways, pancreas and sweat glands. In order to investigate the post-translational ligation of CFTR with reconstructed functional chloride ion channel and the split Ssp DnaB intein-mediated protein trans-splicing was explored to co-deliver CFTR gene into eukaryotic cells with two vectors. The human CFTR cDNA was split after Glu838 codon before the second transmembrane dome (TMD2) into two halves of N- and C-parts and fused with the coding sequences of split Ssp DnaB intein. Pair of eukaryotic expression vectors pEGFP-NInt and pEYFP-IntC were constructed by inserting them into the vectors pEGFP-N1 and pEYFP-N1 respectively. The transient expression was carried out for observing the ligation of CFTR by Western blotting and recording the chloride current by patch clamps when cotransfection of the pair of vectors into baby hamster kidney (BHK) cells. The results showed that an obvious protein band proven to be ligated intact CFTR can be seen and a higher chloride current and activity of chloride channel were recorded after cotransfection. These data demonstrated that split Ssp DnaB intein could be used as a strategy in delivering CFTR gene by two vectors providing evidence for application of dual adeno-associated virus (AAV) vectors to overcome the limitation of packaging size in cystic fibrosis gene therapy.
Animals ; Cell Line ; Chloride Channels ; physiology ; Cricetinae ; Cystic Fibrosis Transmembrane Conductance Regulator ; biosynthesis ; genetics ; Dependovirus ; genetics ; Genetic Vectors ; Humans ; Membrane Potentials ; genetics ; Protein Processing, Post-Translational ; Protein Splicing

Chloride (Cl) channels are probably found in every cell, from bacteria to mammals. Cl channels are distributed both in the plasma membrane and in intracellular organelles. Three well established structural classes of plasma membrane chloride channels now exist: the ligand-gated chloride channels, the cAMP-stimulated cystic fibrosis transmembrane conductance regulator channel, and the voltage-gated (or swelling-activated) members of the ClC chloride channel family. They have diverse functions, ranging from regulation of cell volume to transepithelial transport, homeostasis, and stabilization of membrane potential, signal transduction and acidification of intracellular organelles. These different functions require the presence of many distinct Cl channels, which are differentially expressed and regulated by various stimuli. A combination of mutagenesis and biophysical analysis has been used to correlate their structure with function. Also their physiological roles are explained by genetic defects leading to various inherited disease and knock-out mouse models. Thus, the loss of Cl channels leads to an impairment of transepithelial transport in Bartter's syndrome, to increased excitability in congenital myotonia, and to reduced endosomal acidification and impaired endocytosis in Dent's disease. Three major structural classes of chloride channels are known to date, but there may be others not yet identified at the molecular level. This review focuses on voltage-gated members of the ClC chloride channel family and their physiological roles.
Animals ; Bacteria ; Bartter Syndrome ; Cell Membrane ; Cell Size ; Chloride Channels ; Cystic Fibrosis Transmembrane Conductance Regulator ; Dent Disease ; Endocytosis ; Homeostasis ; Humans ; Ion Channels ; Mammals ; Membrane Potentials ; Mice ; Mutagenesis ; Myotonia ; Organelles ; Signal Transduction

OBJECTIVETo study the impact of the chloride channel dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) on the cytoskeleton of Sertoli cells in the mouse.

METHODSTM4 Sertoli cells were cultured and treated with CFTR(inh)-172 at the concentrations of 1, 5, 10 and 20 μmol/L for 48 hours. Then the cytotoxicity of CFT(inh)-172 was assessed by CCK-8 assay, the expressions of F-actin and Ac-tub in the TM4 Sertoli cells detected by immunofluorescence assay, and those of N-cadherin, vimentin and vinculin determined by qPCR.

RESULTSCFTR(inh)-172 produced cytotoxicity to the TM4 Sertoli cells at the concentration of 20 μmol/L. The expressions of F-actin and Ac-tub were decreased gradually in the TM4 Sertoli cells with the prolonging of treatment time and increasing concentration of CFTR(inh)-172 (P < 0.05). The results of qPCR showed that different concentrations of CFTR(inh)-172 worked no significant influence on the mRNA expressions of N-cadherin, vimentin and vinculin in the Sertoli cells.

CONCLUSIONThe CFTR chloride channel plays an important role in maintaining the normal cytoskeleton of Sertoli cells. The reduced function and expression of the CFTR chloride channel may affect the function of Sertoli cells and consequently spermatogenesis of the testis.

Actins ; metabolism ; Animals ; Benzoates ; pharmacology ; Chloride Channels ; physiology ; Cystic Fibrosis Transmembrane Conductance Regulator ; antagonists & inhibitors ; Cytoskeleton ; drug effects ; Male ; Mice ; Sertoli Cells ; drug effects ; metabolism ; Spermatogenesis ; Thiazolidines ; pharmacology ; Time Factors

Established antiepileptic drugs (AEDs) decrease membrane excitability by interacting with neurotransmitter receptors or ion channels. AEDs developed prior to 1980 appear to act on sodium channels, gamma-amino butyric acid type A (GABA(A)) receptors or calcium channels. Benzodiazepines and barbiturates enhance GABA(A) receptormediated inhibition. Barbiturates increase the duration of chloride channel opening and at higher doses, they block voltage-dependent calcium channels presynaptically, decreasing excitatory amino acid (EAAs) transmission. Benzodiazepines also interact with the GABA(A) receptor complex and increase the frequency of chloride channel opening. Phenytoin, carbamazepine and possibly sodium valproate decrease high frequency repetitive firing of action potentials by enhancing sodium channel inactivation. At higher doses, PHT may block sodium channels presynaptically and decrease EAAs release. In addition to the action on sodium channel, CBZ interacts with adenosine receptor and decrease C-AMP, and block reuptake of norepinephrine. VPA shows diverse mechanisms including sodium channel blocking. It increases synaptosomal GABA by increasing production and decreasing break-down and interacts with T-type calcium channels preventing thalamocortical interaction necessary for absence. Ethosuximide and sodium valproate reduce a low threshold (T-type) calcium channel current. The mechanisms of action of newly developed AEDs are not fully established. Felbamate is broad-spectrum, and probably has multiple actions on sodium channels, interaction with GABA(A) receptors, and interaction with NM.D.A receptors. Gabapentin binds to a high affinity site on neuronal membranes in a restricted regional distribution of the CNS. This binding site may be related to a possible active transport process of gabapentin into neurons. However this has not proven and the mechanism of action of gabapentin remains uncertain. It is structurally related to GABA and its action of antiepileptic activity is suspected due to change of neuronal amino acids (interfere glutamate synthesis, block GABA uptake, and enhance GABA release). Lamotrigine, initially developed as an antifolate drug, decreases sustained high frequency repetitive firing of voltage-dependent sodium action potentials that may result in a preferential decreased release of presynaptic glutamate. It may also interact with GABA receptors but its primary antiepileptic action is on the sodium channel similar to the PHT and CBZ. Because of such a diverse mechanism of action, LTG is one of the wide spectrum AEDs. Oxcarbazepine's mechanism of action is not known ; however, its similarity in structure and clinical efficacy to that of carbamazepine suggests that its mechanism of action may involve inhibition of sustained high frequency repetitive firing of voltage-dependent sodium action potentials. Vigabatrin is a "designer" drug as is developed rationally, and it reversibly inhibits GABA transaminase, the enzyme that degrades GABA, thereby producing greater available pools of presynaptic GABA for release in central synapses. Increased activity of GABA at postsynaptic receptors may underlie the clinical efficacy of VGB. Tiagabine is a potent blocker of GABA re-uptake by glia and neuron.
4-Aminobutyrate Transaminase ; Action Potentials ; Amino Acids ; Anticonvulsants* ; Barbiturates ; Benzodiazepines ; Binding Sites ; Biological Transport, Active ; Butyric Acid ; Calcium Channels ; Calcium Channels, T-Type ; Carbamazepine ; Chloride Channels ; Ethosuximide ; Excitatory Amino Acids ; Fires ; gamma-Aminobutyric Acid ; Glutamic Acid ; Ion Channels ; Membranes ; Neuroglia ; Neurons ; Neurotransmitter Agents ; Norepinephrine ; Phenytoin ; Receptors, GABA ; Receptors, GABA-A ; Receptors, Neurotransmitter ; Receptors, Purinergic P1 ; Sodium ; Sodium Channels ; Synapses ; Valproic Acid ; Vigabatrin