Transmembrane Regulator Protein Research Articles

Cystic fibrosis diagnosed in a nineteen-year-old case

Cystic fibrosis is the most common autosomal recessive hereditary disease in white populations. It is characterized by the formation of abnormal secretions in the exocrine glands located in the sweat and salivary glands, tracheobronchial tree, large intestine, and pancreas. The severity of the clinic depends on the type of "cystic fibrosis transmembrane regulatory protein" gene mutation. Although most cases are diagnosed in infancy or childhood, some patients are also diagnosed during adolescence and adulthood. We report a case of a 19-year-old patient who was followed up with a diagnosis of asthma and bronchiectasis since childhood and diagnosed with cystic fibrosis.

Low-grade Appendiceal Mucinous Neoplasm (Appendiceal Villous Adenoma) with Cystic Fibrosis: A Case Report

Cystic fibrosis (CF) is an autosomal dominant disease characterized by the dysfunction of exocrine secretory glands resulting from a mutation in the transmembrane regulator protein (CFTR) gene. As life expectancy increases in patients with cystic fibrosis secondary to advances in treatment, advanced age malignancies secondary to cystic fibrosis emerge. Especially, the frequency of gastrointestinal system malignancies and colon cancers increases with aging. Appendiceal tumors are a rare entity and constitute less than 1% of gastrointestinal tumors. We presented a villous adenoma encountered in an 18-year-old male patient with CF accompanied by clinical and radiological findings. Our case is the first reported appendiceal tumor that emerged in patients with cystic fibrosis.

Structure and co-occurrence patterns of bacterial communities associated with white faeces disease outbreaks in Pacific white-leg shrimp Penaeus vannamei aquaculture

Bacterial diseases cause production failures in shrimp aquacultures. To understand environmental conditions and bacterial community dynamics contributing to white faeces disease (WFD) events, we analysed water quality and compared bacterial communities in water as well as in intestines and faeces of healthy and diseased shrimps, respectively, via 16S rRNA gene sequencing and qPCR of transmembrane regulatory protein (toxR), thermolabile haemolysin (tlh), and thermostable direct haemolysin genes of pathogenic Vibrio parahaemolyticus as a proxy for virulence. WFD occurred when pH decreased to 7.71–7.84, and Alteromonas, Pseudoalteromonas and Vibrio dominated the aquatic bacterial communities. The disease severity further correlated with increased proportions of Alteromonas, Photobacterium, Pseudoalteromonas and Vibrio in shrimp faeces. These opportunistic pathogenic bacteria constituted up to 60% and 80% of the sequences in samples from the early and advances stages of the disease outbreak, respectively, and exhibited a high degree of co-occurrence. Furthermore, toxR and tlh were detected in water at the disease event only. Notably, bacterial community resilience in water occurred when pH was adjusted to 8. Then WFD ceased without a mortality event. In conclusion, pH was a reliable indicator of the WFD outbreak risk. Dissolved oxygen and compositions of water and intestinal bacteria may also serve as indicators for better prevention of WFD events.

Unveiling epidemiology and treatment strategies for efficient management of lung infection in cystic fibrosis

Cystic Fibrosis (CF) is a genetic disorder which results in abnormal Cystic Fibrosis Transmembrane Regulator (CFTR) protein. CFTR protein actively transports chloride and bicarbonate out of cells which produce mucus in epithelium of various organs. However, when there is an abnormality in this protein then ion and water transport across airway surface is affected and form viscous mucus due to dehydration. This disease affects lung, pancreases, intestine and hepatobiliary system. Infection of lungs is main reason of high morbidity and mortality. Patients with CF are more prone to bacterial infection of the respiratory tract. Mainly four bacterial pathogens are found in the respiratory tract of CF patient viz. Staphylococcus aureus, Haemophilus influenzae, Burkholderia cepacia, Pseudomonas aeruginosa. Mucoid P. aeruginosa is the most dangerous pathogen among them due to ability to form biofilm. There are many conventional and new treatment options available for CF patients. New therapies are used to correct the CFTR protein and antibiotic treatment is used to prevent or early infection or suppression of chronic infection. However, when P. aeruginosa turn into mucoid form, formation of extracellular polysaccharide biofilm starts with alginate as major constituent. The antibiotics fail to reach the target as EPS of the biofilm shield the microbe from antibiotics action. Alginate lyase, an alginate degrading has the ability to break the alginate and subsequently increases the efficacy of antibiotics therapy. The co-administration of alginate lyase and Dnase along with antibiotics has proved to be very efficient in the management of patients with CF.

R117H mutation of the gene encoding the cystic fibrosis transmembrane regulatory protein in patients with chronic relapsing pancreatitis

R117H mutation of the gene encoding the cystic fibrosis transmembrane regulatory protein in patients with chronic relapsing pancreatitis

Interaction Between ITM2B and GLUT9 Links Urate Transport to Neurodegenerative Disorders.

Hyperuricemia plays a critical causative role in gout. In contrast, hyperuricemia has a protective effect in neurodegenerative disorders, including Alzheimer’s Disease. Genetic variation in the SLC2A9 gene, encoding the urate transporter GLUT9, exerts the largest single-gene effect on serum uric acid (SUA). We report here the identification of two GLUT9-interacting proteins, integral membrane protein 2B (ITM2B) and transmembrane protein 85 (TMEM85), isolated from a human kidney cDNA library using the dual-membrane yeast two-hybrid system. ITM2B is a ubiquitously expressed, N-glycosylated transmembrane regulatory protein, involved in familial dementias and retinal dystrophy; the function of TMEM85 is less defined. Using coimmunoprecipitation, we confirmed the physical interaction between ITM2B or TMEM85 and N-terminal GLUT9 isoforms (GLUT9a and GLUT9b) in transfected HEK 293T cells and Xenopus oocytes, wherein ITM2B but not TMEM85 inhibited GLUT9-mediated urate uptake. Additionally, co-expression of ITM2B with GLUT9 in oocytes inhibited N-glycosylation of GLUT9a more than GLUT9b and stimulated urate efflux by both isoforms. However, urate uptake by N-glycosylation and N-terminal deletion GLUT9 mutants was efficiently inhibited by ITM2B, indicating that neither N-glycosylation nor the N terminus is necessary for functional interaction of GLUT9 with ITM2B. Notably, ITM2B variants linked to familial Danish dementia and retinal dystrophy significantly attenuated the inhibition of GLUT9–mediated urate influx. We propose ITM2B as a potential regulatory link between urate homeostasis and neurodegenerative disorders.

Cystic Fibrosis Transmembrane Conductance Regulator. Implications in Cystic Fibrosis and Chronic Obstructive Pulmonary Disease.

Cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) have traditionally been viewed as two distinct entities of unrelated origins. However, molecular, cellular, and clinical studies have revealed that cystic fibrosis transmembrane conductance regulator (CFTR) protein dysfunction is common to both conditions, one (CF) being defined genetically and the other (COPD) as an acquired CFTR deficiency. Multiple molecular mechanisms of cigarette smoke-induced CFTR dysfunction have been reported. More importantly, considerable evidence of cigarette smoke-induced CFTR dysfunction in several respiratory and nonrespiratory tissues have been confirmed, making CFTR a target that cannot be overlooked in our quest to understand COPD and improve therapies for individuals affected by this disease. This review summarizes the molecular, cellular, and clinical evidence that CFTR dysfunction is induced by cigarette smoke exposure both in vitro and in vivo, and explores how this may contribute to the development of COPD.

AB174. Genetic counseling in the couple with compound heterozygous carrier based on the result of mutation effect analysis on cystic fibrosis transmembrane conductance regulator (CFTR) protein

Background Cystic fibrosis (CF) is an autosomal recessive disorder due to mutation(s) in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. In Caucasian population, CF is routinely screened in the newborns and also couple with CF family history due the high incidence and prevalence. The V322A missense mutation was detected from a man whose expecting spouse is carrier for F508del. F508del is known as the most common severe CF-causing mutation, while the effect of V322A mutation is still unknown. If V322A is deleterious, the F508del/V322A baby will suffer from CF, thus prenatal diagnosis is necessary. To evaluate the impact of V322A mutation to CFTR protein in silico and in vitro and to provide proper genetic counselling to the couple with compound heterozygous carrier.

Combination Therapy in Patients with Cystic Fibrosis Targets Underlying Dysfunction

Mutations in the gene for cystic fibrosis transmembrane conductance regulator (CFTR) protein, an anion channel in the epithelial cell membrane, result in abnormal amounts or activity of the protein. About 45% of patients with cystic fibrosis are homozygous for the most common CFTR mutation (Phe508del); median survival among this cohort in the U.S. is 37 years. Researchers studied a combination of a recently approved drug, ivacaftor, and an investigational drug, lumacaftor, …

A new era of personalized medicine for cystic fibrosis - at last!

The gene responsible for cystic fibrosis (CF) was discovered 25 years ago. This breakthrough has enabled a sophisticated understanding of how various mutations lead to specific alterations in the structure and function of the CF transmembrane regulator (CFTR) protein. Until recently, all therapies in CF were focused on ameliorating the downstream consequences of CFTR dysfunction. High-throughput drug screening approaches have yielded compounds that can modify CFTR structure and function, thus targeting the basic defect in CF. The present article describes the CFTR mutational classes, reviews mutation-specific therapies currently in late-phase clinical development, and highlights research opportunities and challenges with personalized medicine in CF.

Flavonoids and flavonoid-rich natural extracts inhibit cytokine release in cystic fibrosis bronchial epithelial cells by regulating NF-kB pathway

Cystic fibrosis (CF) is a genetic life-shortening condition in Caucasians. Despite being a multi-organ disease, CF is classically diagnosed by symptoms of acute/chronic respiratory disease, with persistent pulmonary infections (Amaral, 2015). CF is caused by mutations in the gene encoding cystic fibrosis transmembrane conductance regulator (CFTR) protein. Inheritance of mutant CFTR alleles results in surface liquid depletion and defective mucociliary clearance leading to pulmonary failure. Defects in CFTR perturb the regulation of many intracellular signaling pathways including the NF-kB pathway causing excessive production of pro-inflammatory mediators. Current CF therapies are directed to delay CF lung damage by restoring CFTR function and controlling abnormal inflammation. However, only few anti-inflammatory drugs are effective for CF treatments (mainly oral corticosteroids and ibuprofen), these drugs have limited beneficial effects in presence of considerable side effects. Flavonoids have been reported as promising anti-inflammatory drugs and some of them seem to act as CFTR direct activators (Amaral, 2015). From this respect, herbal remedies or plant bioactive molecules may be of great interest. To this aim, we tested the anti-inflammatory activity of apolar extracts from the roots of three Peonia species (Paeoniaceae family), namely P. rockii P. ostii and P. lactiflora , on CFTR ΔF508/ΔF508 CuFi1 cells and normal counterpart. The effects of the extracts on intrinsic as well as TNFα-induced inflammation were evaluated by determining IL-8, IL-6 and RANTES production. Further- more, to study the direct effect of the extracts on NF-kB activation, Human Embryonic Kidney cells were used in transient transfection of NF-kB reporter plasmid and NF-kB activity and cytokine productions were also evaluated. Results showed a significant anti-inflammatory activity of all three Peonia extracts with the P. lactiflora being the most effective. Furthermore, we also tested the anti-inflammatory potential of the pure flavonoid naringin in the same model systems. We found that naringin was able to reduce cytokine release through inhibiting the key enzymes of the NF-kB and MAPK/ ERK pathways. Interestingly, preliminary results on spray dried pharmaceutical formulations of this molecule, show that naringin co-sprayed with leucine improves pharmacological activity of the flavonoid neat raw drug.

Abstract WP262: Therapeutically Targeting TNFa-S1P Signaling Restores Microvascular Reactivity after Experimental Subarachnoid Hemorrhage

Background: Subarachnoid hemorrhage (SAH) is characterized by an initial hemorrhagic and ischemic brain injury followed by delayed macro- and microvascular constriction. Large-artery vasospasm and enhanced microcirculatory myogenic tone may contribute to delayed cerebral ischemia. Although this implies that therapeutic interventions must specifically correct the SAH-induced myogenic tone enhancement, current therapeutic approaches non-selectively interfere with vasoconstriction and risk disrupting cerebral autoregulation. This may explain why most interventions do not improve clinical outcome. This study identifies the molecular basis for exacerbated cerebrovascular constriction and validates new targets for SAH treatment. Methods: Wild-type, tumor necrosis factor α (TNFα) knockout, sphingosine-1-kinase (Sphk1) knockout and inducible, smooth muscle cell-targeted TNFα knockout mice were used. SAH was created by injection of 80 μl of arterial blood into the prechiasmatic cistern. Myogenic tone in the olfactory artery was assessed with a myograph system. Standard procedures for fluorescent immunolocalization, Western blotting and assessment of apoptosis were used. Results: SAH increased myogenic tone and vascular wall TNFα expression, without enhancing overall vascular contractility in response to phenylephrine. Knockout of TNFα globally or smooth muscle cell-specifically prevented SAH-induced increased myogenic tone. Inhibition of TNFα-shedding (TAPI, 50 μmol/L) or receptor-binding (etanercept, 10 mg/ml) eliminated SAH-mediated myogenic tone augmentation. Cystic fibrosis transmembrane regulator (CFTR) protein expression was down-regulated in cerebral arteries after SAH, which was abolished by antagonism of TNFα. Genetic mouse models confirmed that S1P signaling mediates the myogenic tone augmentation in SAH. Finally, disrupting TNFα signaling attenuated neuronal apoptosis in SAH animals. Conclusion: We identify a novel smooth muscle cell autocrine/paracrine signaling network that augments myogenic tone in SAH. It links TNFα, CFTR and sphingosine-1-phosphate (S1P) signaling. Targeting TNFα and the S1P 2 receptor subtype are potential therapeutic options to improve clinical outcome in SAH.

Avaliação e recomendações nutricionais para crianças e adolescentes com fibrose cística

OBJETIVO: Revisar e discutir evidências sobre a avaliação do estado nutricional e as recomendações para o tratamento nutricional de crianças e adolescentes com fibrose cística. FONTES DE DADOS: Bancos de dados MEDLINE (versão PubMed) e Latin American and Caribbean Center on Health Sciences Information (LILACS), entre 1984 a 2009. Aplicou-se a combinação dos seguintes descritores: fibrose cística, estado nutricional, criança e adolescente - em inglês e português. SÍNTESE DOS DADOS: A fibrose cística é uma doença genética, de evolução crônica, progressiva e fatal. Resulta do defeito na proteína reguladora transmembrana que regula a condução de cloro e, consequentemente, o fluxo de sódio e água através da membrana apical das células epiteliais. Pacientes fibrocísticos são vulneráveis à desnutrição, que resulta do desequilíbrio entre ingestão alimentar, gasto e perdas energéticas. Novos conhecimentos sobre a fisiopatologia da doença, adquiridos nas últimas décadas, resultaram em mudanças significativas nas atuais recomendações energéticas e principalmente de lipídeos. A importância da nutrição no bem-estar e sobrevida dos fibrocísticos está bem estabelecida, assim como a associação entre a desnutrição e a deterioração da função pulmonar. Existem múltiplos fatores inter-relacionados que afetam o estado nutricional, tais como, mutação genética, insuficiência pancreática, ressecção intestinal, perda de sais e ácidos biliares, refluxo gastroesofágico, inflamação e infecções pulmonares, diabetes e condições emocionais. CONCLUSÕES: O monitoramento nutricional e o aconselhamento dietético são elementos chave no manejo de crianças e adolescentes com fibrose cística com o intuito de controlar a sintomatologia e a progressão da doença, proporcionando melhor qualidade de vida.

18 Search for modifier genes in F508del homozygous cystic fibrosis patients

Background: Systemic insufficiency occurred in cystic fibrosis (CF) and absence of complete genotype/phenotype correlation especially with reference to CF lung disease indicates that Cystic Fibrosis Transmembrane Regulator (CFTR) protein play also other than chloride channel function in the cell. Observed in CF retardation in the Na+ ions trafficking through the Epithelial Sodium Channel (ENaC) channel is the results of disturbances in interaction between CFTR and ENaC. It has the effect on the composition of the airway surface liquid and the mucociliary clearance in the airways. Objectives: The aim of the study was to check whether ENaC/CFTR genotype may predispose to CF phenotype Patients and Methods: Using sequencing analysis (ABI PRISM 3730, Applied Biosystems Inc, CA, USA) we screened for mutation in SCNN1a, SCNN1b and SCNN1W genes, encoded three subunit of ENaC in 30 patients with bronchiectasis, elevated sweat chloride ( C (p.W493R) in SCNN1a (14%). This mutation is known to increase ENaC activity four-fold and might contribute to CF phenotype. Conclusions: Presence of ENaC mutations in patients with clinical CF and incomplete CFTR genotype predispose to CF phenotype. It indicates polygenic mechanism of the disease. Supported by Polish Ministry of Science and Higher Education

Analysis of DEFB1 regulatory SNPs in cystic fibrosis patients from North‐Eastern Italy

Cystic fibrosis (CF) transmembrane regulator protein (CFTR) gene is undoubtedly the main genetic factor involved in the modulation of CF phenotype. However, other factors such as human defensins and the genes encoding for these antimicrobial peptides have been hypothesized as possible modifiers influencing airways infection in CF patients, but their role in the pathogenesis of lung disease is still debated. Since DEFB1 gene encoding for human beta-defensin 1 displays features such as antimicrobial or chemotactic activity playing a role in inflammation, it has been considered as a possible candidate CF modifier gene. We analysed three single nucleotide polymorphisms (SNPs) in the 5'-untranslated region of the DEFB1 gene (namely g-52G>A, g-44C>G and g-20G>A) in a group of 62 CF patients from North Eastern Italy, and in 130 healthy controls, with the aim of verifying the possible association of these functional SNPs with the pulmonary phenotype of CF patients. DEFB1 SNPs have been genotyped by using Taqman allele-specific fluorescent probes and a real-time PCR platform. No significant differences were found for allele, genotype and haplotype frequencies of DEFB1 g-52G>A, g-44C>G and g-20G>A SNPs in CF patients stratified for Pseudomonas aeruginosa infection, as well as in patients with a severe and mild clinical phenotype or in patients stratified for CFTR genotypes. DEFB1 allele, genotype and haplotype frequencies of CF patients globally considered were similar to those of healthy controls. Our findings are discordant with respect to another recent study performed on CF patients coming from Southern Italy, probably due to different ethnicity of the patients.

Influence of membrane organization on the dimerization ability of ToxR from Photobacterium profundum under high hydrostatic pressure

High hydrostatic pressure (HHP) is suggested to influence bacterial physiology by changing the structure and function of membranes and/or integral membrane proteins. In this work, the HHP-modulated dimerization behavior of the transmembrane regulatory protein ToxR from Photobacterium profundum SS9 was investigated, in response to changes in membrane organization induced by temperature and addition of phenethyl alcohol, in a background of different organisms (Escherichia coli and P. profundum) and mutants deficient in unsaturated fatty acid synthesis. Reporter strains were constructed by chromosomal integration of an ompL-promoter lacZ fusion cassette. Arabinose-controlled ToxR expression was achieved by plasmid pBADK-ToxR-his. The results demonstrate that changes in the lipid environment have a marginal effect on the function of ToxR; instead, ToxR activity appears to be largely determined by the properties of the protein itself.

Potential role of the "NADPH oxidases" (NOX/DUOX) family in cystic fibrosis.

Cystic fibrosis (CF), is the most common life-shortening autosomal recessive disorder in Caucasians. It is caused by mutations in a single gene on the long arm of chromosome 7 that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by abnormal Na+ and Cl- ion transport in several tissues, including the lungs, pancreas, gastrointestinal tract, liver, sweat glands, and male reproductive system. Progressive pulmonary disease is the dominant clinical feature of CF and accounts for morbidity and mortality. The inflammation characterized by an overabundance of activated neutrophils and macrophages on the respiratory epithelial surface is associated to a high production of reactive oxygen species (ROS) which contribute to the pathogenesis of cystic fibrosis. ROS could have different origins but the role of the NADPH oxidase system is essential. The "NADPH oxidases" (NOX/DUOX) family is an enzymatic complex formed by cytosolic and membrane subunits. Until now several homologues of the phagocytic NADPH oxidase have been identified in different tissues and it has been shown that the lungs preferentially expressed DUOX1-2. Thus, DUOX1-2 could be implicated in the anti-infectious defense system. The role of DUOX enzymes as a source of ROS in cystic fibrosis is examined as they could contribute to a better understanding of molecular mechanisms in CF. Moreover they could be a potential target for a new therapeutic approach.

Immunohistochemical Localization of Cystic Fibrosis Transmembrane Regulator and Clara Cell Secretory Protein in Taste Receptor Cells of Rat Circumvallate Papillae

Taste receptor cells (TRCs) are the sensory cells of taste transduction and are organized into taste buds embedded in the epithelium of the tongue, palate, pharynx, and larynx. Several studies have demonstrated that TRCs involved in sweet as well as bitter and umami responses express alpha-gustducin, an alpha-subunit of the G-protein complex. It has been further demonstrated that this typical taste protein is a potent marker of chemosensory cells located in several tissues, including gastric and pancreatic mucosa and the respiratory apparatus. We recently observed that alpha-gustducin and phospholipase C beta 2-immunoreactive cells were colocalized in the airways with cystic fibrosis transmembrane regulator (CFTR) and Clara cell-specific secretory protein of 10 (CC10) and 26 kDa (CC26). This finding suggests that TRCs might themselves express secretory markers. To test this hypothesis, we investigated the expression of CFTR, CC10, and CC26 in rat circumvallate papillae using reverse transcriptase-polymerase chain reaction analysis, immunohistochemistry, and confocal laser microscopy. The results showed that secretory markers such as CFTR, CC10, and CC26 are present in taste cells of rat circumvallate papillae, and their immunoreactivity is expressed, to a different extent, in subsets of taste cells that express alpha-gustducin. The presence of CFTR, CC10, and CC26 in taste bud cells and their coexpression pattern with alpha-gustducin confirms and extends our previous findings in airway epithelium, lending further credence to the notion that chemoreception and secretion may be related processes.

Lung Transplantation in Cystic Fibrosis — Primum Non Nocere?

Cystic fibrosis is one of the most common autosomal recessive diseases. It causes intestinal, pancreatic, and progressive lung dysfunction, which is ultimately lethal. In 1989, the first specific cystic fibrosis gene defect on chromosome 7 was described, and its function was determined shortly thereafter. The cystic fibrosis gene codes for the cystic fibrosis transmembrane regulator (CFTR) protein, a chloride channel that controls chloride and, indirectly, sodium transport across epithelial cells. When CFTR function is lost, excess sodium and chloride are resorbed from the airway lumen, leading to dehydration of the luminal contents and increased fluid viscosity of the airway lining. . . .

1009. Expression of the Cystic Fibrosis Transmembrane Regulator (CFTR) Protein Following Recombination between Two AAV Vectors

1009. Expression of the Cystic Fibrosis Transmembrane Regulator (CFTR) Protein Following Recombination between Two AAV Vectors