Neutrophil unsaturated fatty acid release by GM-CSF is impaired in cystic fibrosis

Dysregulated inflammation in cystic fibrosis (CF) is attributed to an altered production of inflammatory mediators derived from polyunsaturated lipids. In comparison to the arachidonic acid (AA) cascade, little is known about the modulation of docosahexaenoic acid (DHA) membrane release. We compared data on neutrophil DHA- and AA- release from both control (CT) and patients with CF using [3H]AA or [14C]DHA as a markers for, respectively, AA and DHA- release. Granulocyte-macrophage-colony stimulating factor stimulated DHA release from CT, but not CF, neutrophils. Comparison showed that both [14C]DHA and [3H]AA liberated after stimulation was higher in CT than in CF neutrophils. Since bioactive mediators derived from DHA are resolving factors and those derived from AA are both pro- and anti- inflammatory, these results suggest that CF is associated with a reduction of the release of PUFA-precursors of lipooxygenated resolving mediators. This leads to the hypothesis that defects in the resolving factors production could contribute to the inflammatory dysregulated processes in CF. Furthermore, the methodology used may help to improve knowledge on the regulation and resolution of inflammation

Synergistic Post-Transcriptional Regulation of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) by miR-101 and miR-494 Specific Binding

microRNAs (miRNAs) are a class of regulatory small non-coding molecules that control gene expression at post-transcriptional level. Deregulation of miRNA functions affects a variety of biological processes also involved in the etiology of several human mendelian and complex diseases. Recently, aberrant miRNA expression has been observed in Cystic Fibrosis (CF), an autosomal-recessive genetic disorder caused by mutations in the CFTR gene, in which a genotype-phenotype correlation is not always found. In order to determine miRNA role in CFTR post-transcriptional regulation, we searched for miR-responsive elements in the CFTR 3′-UTR. In silico analysis, performed using different computational on-line programs, identified some putative miRNAs. Both miR-101 and miR-494 synthetic mimics significantly inhibited the expression of a reporter construct containing the 3′-UTR of CFTR in luciferase assays. Interestingly, miR-101/miR-494 combination was able to markedly suppress CFTR activity by approximately 80% (p<0.001). This is one of the first in vitro studies implicating microRNAs as negative regulators of the CFTR gene expression. miRNA aberrant expression and function might explain the wide phenotypic variability observed among CF patients

A Genotypic-oriented View of CFTR Genetics Highlights Specific Mutational Patterns Underlying Clinical Macro-categories of Cystic Fibrosis.

Cystic Fibrosis (CF) is a monogenic disease caused by mutations of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. The genotype-phenotype relationship in this disease is still unclear, and diagnostic, prognostic and therapeutic challenges persist. We enrolled 610 patients with different forms of CF and studied them from a clinical, biochemical, microbiological and genetic point of view. Overall, 125 different mutated alleles (11 of which with novel mutations and 10 of which complex) and 225 genotypes were found. A strong correlation between mutational patterns at the genotypic level and phenotypic macro-categories emerged. This specificity appears to be largely dependent on rare and individual mutations, as well as on the varying prevalence of common alleles in different clinical macro-categories. However, 19 genotypes appeared to underlie different clinical forms of the disease. The dissection of the pathway from the CFTR mutated genotype to the clinical phenotype allowed to identify at least two components of the variability usually found in the genotype - phenotype relationship. One component seems to depend on the genetic variation of CFTR, the other component on the cumulative effect of variations in other genes and cellular pathways independent from CFTR. The experimental dissection of the overall biological CFTR pathway appears to be a powerful approach for a better comprehension of the genotype - phenotype relationship. However, a change from an allele-oriented to a genotypic-oriented view of CFTR genetics is mandatory, as well as a better assessment of sources of variability within the CFTR pathway

Impact of clonally-related Burkholderia contaminans strains in two patients attending an Italian cystic fibrosis centre. A case report

Background: Burkholderia contaminans is one of the 20 closely related bacterial of the Burkholderia cepacia complex, a group of bacteria that are ubiquitous in the environment and capable of infecting people with cystic fibrosis (CF). This species is an emerging pathogen and it has been widely isolated from CF patients in Argentina, Spain, Portugal, Australia, Canada, USA with a low prevalence in Ireland, France, Russia, Switzerland, Czech Republic, and Italy. This is the first report of B. contaminans affecting two Italian CF patients attending the same CF Centre. We correlate B. contaminans colonisation with lung function decline and co-infection with other clinically relevant CF pathogens. Case presentation: B. contaminans was identified by Multi Locus Sequence Typing in routine sputum analysis of two Caucasian CF women homozygous for Phe508del CFTR mutation. Sequence Type 102 was detected in both strains. It is known that B. contaminans ST102 was isolated both from CF and non-CF patients, with an intercontinental spread across the world. Random Amplified Polymorphic DNA analysis revealed the genetic relatedness between the two strains. We examined their susceptibility to antimicrobial agents, comparing the latter with that recorded for other B. contaminans isolated from different countries. We also described key virulence factors possibly linked with a clinical outcome. Specifically, we attempted to correlate colonization with the incidence of acute exacerbation of symptoms and lung function decline. Conclusions: This case presentation suggests that acquisition of B. contaminans ST102 is not directly associated with a lung function decline. We retain that the presence of other CF pathogens (i.e. MRSA and Trichosporon) along with B. contaminans ST102 might have contributed to the worsening of clinical conditions in our CF patients. The circumstances leading to the establishment of B. contaminans ST102 infections are still unknown. We highlight the importance to proper detect and typing bacteria implicated in CF infection by using molecular techniques

Measuring habitual physical activity in adults with cystic fibrosis

SummaryBackgroundThe aim of the present study was to determine whether different methods of recording physical activity (PA), i.e., accelerometers vs questionnaires, provided similar information in adults with cystic fibrosis (CF).Methods20 CF (age 33 ± 8SD yrs, FEV1 68 ± 16% predicted) and 11 age-matched healthy controls completed the Habitual Activity Estimation Scale (HAES) questionnaire and wore a biaxial accelerometer (SenseWear Pro3 Armband). Exercise tolerance was measured in CF.ResultsPatients had similar values in PA compared with controls. None of PA categories estimated by HAES questionnaire correlated with PA categories measured by the accelerometer; in CF the HAES questionnaire overestimated the effective levels of PA measured by the accelerometer. There were no differences between weekdays and weekend days PA levels provided by the accelerometer. In CF the questionnaire detected different time reported during the “somewhat inactive” and “somewhat active” categories (z = 2.651; p = 0.008; z = −2.651; p = 0.008), weekdays vs weekend; patients reported more time spent in activity (somewhat active & very active) during the weekend (z = −2.203; p = 0.02). Peak oxygen uptake correlated with accelerometer activities of “moderate” (>4.8 metabolic equivalents (METS)) and “vigorous” (>7.2 METS) intensity (r = 0.503, p = 0.02; r = 0.545, p = 0.01).ConclusionsIn adults with cystic fibrosis PA levels are better evaluated by the accelerometer and are similar to the controls. PA measured by the accelerometer is similar during the week and correlates with exercise tolerance

Aerosolized lancovutide in adolescents (≥12 years) and adults with cystic fibrosis - a randomized trial.

Abstract Background Lancovutide activates a chloride channel (TMEM-16A) other than the cystic fibrosis (CF) transmembrane conductance regulator protein and could benefit CF patients. Methods In this randomized, multi-center, double-blind, placebo-controlled, parallel-group trial 161 patients ≥12 years with a confirmed diagnosis of CF were randomized to either placebo (saline) or active drug in 3 different dosing schemes of 2.5mg inhaled lancovutide (once daily, every other day or twice a week) for eight weeks. The primary endpoint was the change in the forced expiratory volume in 1 second (FEV1) percent predicted. Secondary endpoints included further lung function parameters (FEV1 (absolute), functional vital capacity percent predicted, forced expiratory flow percent predicted, pulse oximetry), quality of life assessment, pulmonary exacerbations, hospitalization due to pulmonary exacerbations, time to first pulmonary exacerbation, duration of anti-inflammatory, mucolytic or antibiotic treatment, and safety. Results There was no significant difference in the change in FEV1 percent predicted, quality of life, other lung function parameters, pulmonary exacerbations or requirement of additional treatment between groups. Overall, the inhalation of lancovutide was safe although a higher rate of adverse events, especially related to the respiratory system, occurred as compared to placebo. Conclusions Lancovutide did not improve FEV1 percent predicted when compared to placebo (NCT00671736)