Cystic fibrosis (CF) is an autosomal recessive disorder usually found in populations of white Caucasian descent. CF is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. A 5-yr-old Korean girl was admitted complaining of coughing and greenish sputum. Chest radiographs and computed tomographic (CT) scan revealed diffuse bronchiectasis in both lungs. The patient had chronic diarrhea and poor weight gain, and the abdominal pancreaticobiliary CT scan revealed atrophy of the pancreas. Finally, CF was confirmed by the repeated analysis of the quantitative pilocarpine iontophoresis test. The chloride concentration of sweat samples taken from both forearms of the pateint was an average of 88.7 mM/L (normal value <40 mM/L). After a comprehensive search for mutations in the CFTR gene, the patient was found to carry the non-synonymous L441P mutation in one allele. Molecular physiologic analysis of the L441P mutation of CFTR revealed that the L441P mutation completely abolished the CFTR Cl- channel activity by disrupting proper protein folding and membrane trafficking of CFTR protein. These results confirmed the pathogenicity of the L441P mutation of CFTR circulating in the Korean population. The possibility of CF should be suspected in patients with chronic bronchiectasis, although the frequency of CF is relatively rare in East Asia.
Amino Acid Substitution ; Base Sequence ; Cell Line ; Child, Preschool ; Cystic Fibrosis/diagnosis/*genetics ; Cystic Fibrosis Transmembrane Conductance Regulator/*genetics/metabolism ; Female ; Humans ; Lung/radiography ; *Mutation ; Patch-Clamp Techniques ; Republic of Korea ; Tomography, X-Ray Computed

This study is to investigate the activation effect of butyl-p-hydroxybenzoate (Bpb) on cAMP-dependent cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel gating. A stably transfected Fischer rat thyroid (FRT) epithelial cell lines co-expressing human CFTR and a green fluorescent protein mutant with ultra-high halide sensitivity (EYFP) were used to measure CFTR-mediated iodide influx rates. Bpb was identified as an effective activator of wild-type CFTR chloride channel, it can correct delta F508-CFTR gating defects but not processing defect. Bpb can't potentiate G551D-CFTR channel gating. The activity was reversible and dose-dependent. The study also provided clues that Bpb activates CFTR chloride channel through a direct binding mechanism. Our study identified Bpb as a novel structure CFTR activator. Bpb may be useful for probing CFTR channel gating mechanisms and as a lead compound to develop pharmacological therapy for CFTR-related disease.
Animals ; Cell Line ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Epithelial Cells ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; Ion Channel Gating ; drug effects ; Mutation ; Parabens ; administration & dosage ; pharmacology ; Rats ; Rats, Inbred F344 ; Thyroid Gland ; cytology

BACKGROUND: The incidence of lung cancer is gradually increased, and the cystic fibrosis transmembrane conductance regulator (CFTR) has recently demonstrated to have an implication in the deoncogenesis and malignant transformation of many types of cancers. The aim of this study is to investigate impacts of CFTR on the malignant features of lung adenocarcinoma A549 cells. METHODS: The capacity of cell proliferation, migration, invasion and clonogenicity of non-small cell lung cancer A549 cells were detected by CCK8 cell proliferation assay, cell scratch assay, Transwell cell invasion assay and clone formation assay, respectively. Meanwhile, the effect of CFTR gene on the expression of cancer stem cell related transcriptional factors was also detected by immunoblotting (Western blot) assay. RESULTS: An overexpression of CFTR gene in A549 cells significantly inhibited the malignant capacity of A549 cells, including potencies of cell proliferation, migration, invasion and colony formation; while knockdown of CFTR gene expression by RNA interference in A549 cells resulted in an opposite effect seen in above cells overexpressing CFTR gene. Mechanistically, immunoblotting assay further revealed that the ectopic expression of CFTR gene led an inhibitory expression of stem cell-related transcriptional factors SOX2 and OCT3/4, and cancer stem cell surface marker CD133 in A549 cells, while a knockdown of CFTR expression yielded a moderately increased expression of these gene. However, an alteration of CFTR gene expression had neither effect on the expression of putative lung cancer stem cell marker aldehyde dehydrogenase1 (ALDH1), nor the frequency of ALDH1A-positive cells in A549 cells, as ascertained by the immunoblotting assay and cytometry analysis, respectively. CONCLUSIONS The CFTR exhibited an inhibitory role in the malignancy of lung adenocarcinoma A549 cells, suggesting that it may be a novel potential target for lung cancer treatment. However, its functions in other lung adenocarcinoma cell lines and its underlying molecular mechanisms require further investigation.
A549 Cells ; Adenocarcinoma ; pathology ; Adenocarcinoma of Lung ; Cell Movement ; genetics ; Cell Proliferation ; genetics ; Cystic Fibrosis Transmembrane Conductance Regulator ; metabolism ; Humans ; Lung Neoplasms ; pathology ; Mutation ; Neoplasm Invasiveness ; Neoplastic Stem Cells ; pathology ; Proto-Oncogene Proteins p21(ras) ; genetics

After two decades of ups and downs, gene therapy has recently achieved a milestone in treating patients with Leber's congenital amaurosis (LCA). LCA is a group of inherited blinding diseases with retinal degeneration and severe vision loss in early infancy. Mutations in several genes, including RPE65, cause the disease. Using adeno-associated virus as a vector, three independent teams of investigators have recently shown that RPE65 can be delivered to retinal pigment epithelial cells of LCA patients by subretinal injections resulting in clinical benefits without side effects. However, considering the whole field of gene therapy, there are still major obstacles to clinical applications for other diseases. These obstacles include innate and immune barriers to vector delivery, toxicity of vectors and the lack of sustained therapeutic gene expression. Therefore, new strategies are needed to overcome these hurdles for achieving safe and effective gene therapy. In this article, we shall review the major advancements over the past two decades and, using lung gene therapy as an example, discuss the current obstacles and possible solutions to provide a roadmap for future gene therapy research.
Adaptive Immunity ; Carrier Proteins ; genetics ; Cystic Fibrosis ; genetics ; therapy ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; Dependovirus ; genetics ; Eye Proteins ; genetics ; Gene Targeting ; Genetic Therapy ; methods ; Genetic Vectors ; Humans ; Immunity, Innate ; Leber Congenital Amaurosis ; genetics ; therapy ; Liposomes ; Lung ; drug effects ; metabolism ; pathology ; Mutation ; Retina ; drug effects ; metabolism ; pathology ; Retroviridae ; genetics ; cis-trans-Isomerases

The mutation of cystic fibrosis transmembrane conductance regulator (CFTR) gene leads to an autosomal recessive genetic disorder cystic fibrosis (CF). The gene therapy for CF using adeno-associated virus (AAV) vectors delivering CFTR gene is restricted by the contents limitation of AAV vectors. In this study the split CFTR genes severed at its regulatory domain were delivered by a dual-vector system with an intein-mediated protein trans-splicing as a technique to investigate the post-translational ligation of CFTR half proteins and its function as a chloride ion channel. A pair of eukaryotic expression vectors was constructed by breaking the human CFTR cDNA before Ser712 codon and fusing with Ssp DnaB intein coding sequences. After co-transfection into baby hamster kidney (BHK) cells followed by transient expression, patch clamps were carried out to record the chloride current of whole-cell and the activity of a single channel, and the ligation of two halves of CFTR was observed by Western blotting. The results showed that the intein-fused half genes co-transfected cells displayed a high whole cell chloride current and activity of a single channel indicating the functional recovery of chloride channel, and an intact CFTR protein band was figured out by CFTR-specific antibodies indicating that intein can efficiently ligate the separately expressed half CFTR proteins. The data demonstrated that protein splicing strategy could be used as a strategy in delivering CFTR gene by two vectors, encouraging our ongoing research program on dual AAV vector system based gene transfer in gene therapy for cystic fibrosis.
Animals ; Cells, Cultured ; Chlorides ; metabolism ; Codon ; genetics ; Cricetinae ; Cystic Fibrosis ; therapy ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; metabolism ; DNA, Complementary ; genetics ; Dependovirus ; genetics ; Genetic Therapy ; Genetic Vectors ; Humans ; Inteins ; physiology ; Kidney ; cytology ; Protein Processing, Post-Translational ; Recombinant Proteins ; genetics ; metabolism ; Trans-Splicing ; Transfection

OBJECTIVETo determine the expression pattern of Slc26a3 gene in reproductive tract of male rodents to clarify whether the expression pattern is related to the subfertility observed in congenital chloride diarrhea (CLD) disease.

METHODSThe expression of Slc26a3 in mouse and rat epididymis has been studied with immunohistochemistry and Western blotting. Its developmental expression pattern in rat testis was detected by Western blotting, while both of immunofluorescence and Western blotting were used to localize the expression of Slc26a3 in mouse sperms. The potential change of Slc26a3 expression in CFTR (cystic fibrosis transmembrane conductance regulator) knockout mice and CFTR mutant mice was also detected with Western blotting.

RESULTSThe expression level of Slc26a3 gradually decreased along epididymis from its caput to corpus, then to its cauda part. This gradually decreasing expression pattern was also found in rat testis during development. Slc26a3 was localized mainly on the trunk of mouse sperm tail. In the testis and epididymis of CFTR knockout mice and CFTR mutant mice, no significant change of Slc26a3 expression was found.

CONCLUSIONSlc26a3 is expressed in male reproductive tract, and its expression pattern is related to the function. Thus, the subfertility observed in CLD disease may be related to the important role of SLC26A3 in acid-base regulation of epididymis.

Animals ; Antiporters ; genetics ; metabolism ; Blotting, Western ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; metabolism ; Diarrhea ; congenital ; genetics ; metabolism ; Epididymis ; growth & development ; metabolism ; Immunohistochemistry ; Male ; Metabolism, Inborn Errors ; genetics ; metabolism ; Mice, Inbred CFTR ; Mice, Inbred ICR ; Mice, Knockout ; Rats, Sprague-Dawley ; Spermatozoa ; metabolism ; Testis ; growth & development ; metabolism

BACKGROUNDIt has been found that the expression of cystic fibrosis transmembrane conductance regulator (CFTR) is closely related to allergic rhinitis (AR). In the previous study, we have demonstrated that antiallergic herbal agents (AHA) can obviously inhibit the allergic reaction of AR. The aim of this study was to explore the expression of CFTR and the effects of AHA on CFTR to improve the allergic reaction of AR.

METHODSAn animal model of an AR rabbit was established using ovalbumin (OVA). The rhinitis rabbits were randomly assigned to three groups: AHA treating group (AHATG), modeling group (MG) and healthy controlling group (HCG). The expressions of CFTR protein were examined by immunohistochemical method. The mucosal epithelial cells of all the rabbits were primarily cultured with tissue culture method in vitro and treated with or without glibenclamide for 24 hours. The levels of monocyte chemotactic factor-1 (MCP-1) and RANTES protein in supernatants of culture were measured by ELISA, and the expressions of CFTR mRNA were detected by real-time PCR.

RESULTSThe expressions of CFTR mRNA and protein greatly increased in mucosal epithelial cells of MG. The protein concentrations of MCP-1, RANTES in culture supernatants of MG were significantly higher than those in the other two groups (P < 0.01), and they reached much higher level than those at the start points in the MG (P < 0.05) and were significantly different compared with those in the AHATG after being cultured for 24 hours (P < 0.01). CFTR mRNA in MG + glibenclamide were much lower than those in MG (P < 0.05). RANTES and CFTR mRNA treated with glibenclamide in AHATG were significantly lower than those in the AHATG (P < 0.01). Minimal changes in the secretions of MCP-1 in the epithelial cells were detected between AHATG and AHATG + glibenclamide (P > 0.05).

CONCLUSIONSAHA can inhibit the secretions of CFTR, RANTES and MCP-1 in mucosal epithelia and improve inflammatory reaction of AR. CFTR may play an important role in the secretion of RANTES and mucosal inflammatory response in AR. Glibenclamide can inhibit the CFTR secretion in mucosal epithelial cells, in particular during AR process. These effects of glibenclamide on secretion of RANTES can be effectively strengthened by AHA.

Animals ; Cells, Cultured ; Chemokine CCL2 ; genetics ; metabolism ; Chemokine CCL5 ; genetics ; metabolism ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Enzyme-Linked Immunosorbent Assay ; Glyburide ; pharmacology ; therapeutic use ; Immunohistochemistry ; Male ; Mucous Membrane ; drug effects ; metabolism ; Nasal Mucosa ; drug effects ; metabolism ; Polymerase Chain Reaction ; RNA, Messenger ; genetics ; Rabbits ; Random Allocation ; Rhinitis, Allergic, Seasonal ; drug therapy ; metabolism