BMC Pulm Med. 2021 Apr 2;21(1):113. doi: 10.1186/s12890-021-01482-x.

ABSTRACT

BACKGROUND: Physical activity (PA) is a well-documented and accepted adjunct therapy for the maintenance and improvement of long-term health in cystic fibrosis (CF). Although the benefits of PA for CF populations are well-established, adherence to PA programmes within this population remains low. This study aimed to investigate the factors that influence engagement in physical activity, and to explore exercise preferences, among adults with cystic fibrosis (CF).

METHODS: Semi-structured telephone interviews were conducted. Participants were twenty-one adults (mean age 35 years, SD ± 8) with an established diagnosis of CF, living in Ireland. Interview scripts were digitally recorded and transcribed verbatim. Thematic analysis was used to analyse the data.

RESULTS: Four main themes emerged: barriers, motives, value of exercise-related outcomes, and exercise preferences. The main barriers included: low energy levels, time, the weather, and exercise-related confidence. Enjoyment and perceived competence underpinned autonomous motivation. Participants who self-identified as being regularly active valued personally identified exercise-related outcomes such as, accomplishment and affect regulation. Participants indicated a preference for home-based physical activity programs compared to gym- or facility-based programs.

CONCLUSION: Interventions aimed at promoting physical activity among adults with CF should involve programs that foster autonomous motivation, enjoyable activities, personally identified outcomes, competence and that can be conducted from the home environment.

CLINICAL IMPLICATIONS: To increase physical activity participation among adults with CF, interventions that can be conducted from the home environment, that pay attention to the patients' personally-valued exercise outcomes may be required.

PMID:33810783 | DOI:10.1186/s12890-021-01482-x

Int J Environ Res Public Health. 2021 Mar 26;18(7):3452. doi: 10.3390/ijerph18073452.

ABSTRACT

This study aimed to establish the differences in parental attitudes toward feeding and activity, as well as child eating and activity levels, between families of children living with and without asthma. Parents of children and young people aged between 10 and 16 years living both with asthma (n = 310) and without asthma (n = 311) completed measures for parental feeding, parental attitudes toward child exercise, child eating, child activity level and asthma control. Children living with asthma had a significantly higher BMIz (BMI standardised for weight and age) score, were significantly more likely to emotionally overeat and desired to drink more than their peers without asthma. Parents of children with asthma reported greater use of food to regulate emotions, restriction of food for weight control, monitoring of child activity, pressure to exercise and control over child activity. When asthma symptoms were controlled, parental restriction of food for weight management predicted greater child BMIz scores, and higher child activity predicted lower child BMIz scores. These relationships were not found to be significant for children with inadequately controlled asthma. Differences in parental attitudes toward feeding and exercise, and child eating and exercise behaviors, between families may help to explain the increased obesity risk for children with asthma.

PMID:33810395 | DOI:10.3390/ijerph18073452

Microorganisms. 2021 Mar 22;9(3):660. doi: 10.3390/microorganisms9030660.

ABSTRACT

Antibiotic treatment for Pseudomonas aeruginosa (Pa) in cystic fibrosis is limited in efficacy and may lead to multi-drug resistance (MDR). Alternatives such as bacteriophages are being explored but well designed, and controlled trials are crucial. The rational selection of patients with bacteriophage susceptible infections is required for both safety and efficacy monitoring. We questioned whether bacteriophage susceptibility profiles were constant or variable over time, variability having been reported with antibiotics. Serial Pa isolates (n = 102) from 24 chronically infected cystic fibrosis (CF) patients over one year were investigated with plaque and antibiotic disc diffusion assays. Variable number tandem repeat (VNTR) analysis identified those patients with >1 isolate. A median (range) of 4 (3-6) isolates/patient were studied. Twenty-one (87.5%) individuals had a single VNTR type; three (12.5%) had two VNTR types at different times. Seventy-five percent of isolates were sensitive to bacteriophage at ≥ 1 concentration; 50% of isolates were antibiotic multidrug resistant. Serial isolates, even when representing a single VNTR type, varied in sensitivity to both bacteriophages and antibiotics. The rates of sensitivity to bacteriophage supports the development of this therapy; however, the variability in response has implications for the selection of patients in future trials which must be on the basis of current, not past, isolate testing.

PMID:33810202 | DOI:10.3390/microorganisms9030660

Genes (Basel). 2021 Mar 22;12(3):453. doi: 10.3390/genes12030453.

ABSTRACT

Cystic fibrosis (CF) is a life-limiting genetic disorder caused by loss-of-function mutations in the gene which codes for the CF transmembrane conductance regulator (CFTR) Cl- channel. Loss of Cl- secretion across the apical membrane of airway lining epithelial cells results in dehydration of the airway surface liquid (ASL) layer which impairs mucociliary clearance (MCC), and as a consequence promotes bacterial infection and inflammation of the airways. Interventions that restore airway hydration are known to improve MCC. Here we review the ion channels present at the luminal surface of airway epithelial cells that may be targeted to improve airway hydration and MCC in CF airways.

PMID:33810137 | DOI:10.3390/genes12030453

Antibiotics (Basel). 2021 Mar 22;10(3):338. doi: 10.3390/antibiotics10030338.

ABSTRACT

Although new inhaled antibiotics have profoundly improved respiratory diseases in cystic fibrosis (CF) patients, lung infections are still the leading cause of death. Inhaled antibiotics, i.e., colistin, tobramycin, aztreonam lysine and levofloxacin, are used as maintenance treatment for CF patients after the development of chronic Pseudomonas aeruginosa (P. aeruginosa) infection. Their use offers advantages over systemic therapy since a relatively high concentration of the drug is delivered directly to the lung, thus, enhancing the pharmacokinetic/pharmacodynamic parameters and decreasing toxicity. Notably, alternating treatment with inhaled antibiotics represents an important strategy for improving patient outcomes. The prevalence of CF patients receiving continuous inhaled antibiotic regimens with different combinations of the anti-P. aeruginosa antibiotic class has been increasing over time. Moreover, these antimicrobial agents are also used for preventing acute pulmonary exacerbations in CF. In this review, the efficacy and safety of the currently available inhaled antibiotics for lung infection treatment in CF patients are discussed, with a particular focus on strategies for eradicating P. aeruginosa and other pathogens. Moreover, the effects of long-term inhaled antibiotic therapy for chronic P. aeruginosa infection and for the prevention of pulmonary exacerbations is reviewed. Finally, how the mucus environment and microbial community richness can influence the efficacy of aerosolized antimicrobial agents is discussed.

PMID:33810116 | DOI:10.3390/antibiotics10030338

Diagnostics (Basel). 2021 Mar 22;11(3):572. doi: 10.3390/diagnostics11030572.

ABSTRACT

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population and is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that encodes for a chloride/bicarbonate channel expressed on the membrane of epithelial cells of the airways and of the intestine, as well as in cells with exocrine and endocrine functions. A common nonpulmonary complication of CF is cystic fibrosis-related diabetes (CFRD), a distinct form of diabetes due to insulin insufficiency or malfunction secondary to destruction/derangement of pancreatic betacells, as well as to other factors that affect their function. The prevalence of CFRD increases with age, and 40-50% of CF adults develop the disease. Several proposed hypotheses on how CFRD develops have emerged, including exocrine-driven fibrosis and destruction of the entire pancreas, as well as contrasting theories on the direct or indirect impact of CFTR mutation on islet function. Among contributors to the development of CFRD, in addition to CFTR genotype, there are other genetic factors related and not related to type 2 diabetes. This review presents an overview of the current understanding on genetic factors associated with glucose metabolism abnormalities in CF.

PMID:33810109 | DOI:10.3390/diagnostics11030572

Int J Mol Sci. 2021 Mar 12;22(6):2873. doi: 10.3390/ijms22062873.

ABSTRACT

Cell-free therapy using extracellular vesicles (EVs) from adipose-derived mesenchymal stromal/stem cells (ASCs) seems to be a safe and effective therapeutic option to support tissue and organ regeneration. The application of EVs requires particles with a maximum regenerative capability and hypoxic culture conditions as an in vitro preconditioning regimen has been shown to alter the molecular composition of released EVs. Nevertheless, the EV cargo after hypoxic preconditioning has not yet been comprehensively examined. The aim of the present study was the characterization of EVs from hypoxic preconditioned ASCs. We investigated the EV proteome and their effects on renal tubular epithelial cells in vitro. While no effect of hypoxia was observed on the number of released EVs and their protein content, the cargo of the proteins was altered. Proteomic analysis showed 41 increased or decreased proteins, 11 in a statistically significant manner. Furthermore, the uptake of EVs in epithelial cells and a positive effect on oxidative stress in vitro were observed. In conclusion, culture of ASCs under hypoxic conditions was demonstrated to be a promising in vitro preconditioning regimen, which alters the protein cargo and increases the anti-oxidative potential of EVs. These properties may provide new potential therapeutic options for regenerative medicine.

PMID:33808970 | DOI:10.3390/ijms22062873

Genes (Basel). 2021 Mar 19;12(3):441. doi: 10.3390/genes12030441.

ABSTRACT

Cystic fibrosis (CF) is a chronic genetic disease that mainly affects the respiratory and gastrointestinal systems. No curative treatments are available, but the follow-up in specialized centers has greatly improved the patient life expectancy. Robust biomarkers are required to monitor the disease, guide treatments, stratify patients, and provide outcome measures in clinical trials. In the present study, we outline a strategy to select putative DNA methylation biomarkers of lung disease severity in cystic fibrosis patients. In the discovery step, we selected seven potential biomarkers using a genome-wide DNA methylation dataset that we generated in nasal epithelial samples from the MethylCF cohort. In the replication step, we assessed the same biomarkers using sputum cell samples from the MethylBiomark cohort. Of interest, DNA methylation at the cg11702988 site (ATP11A gene) positively correlated with lung function and BMI, and negatively correlated with lung disease severity, P. aeruginosa chronic infection, and the number of exacerbations. These results were replicated in prospective sputum samples collected at four time points within an 18-month period and longitudinally. To conclude, (i) we identified a DNA methylation biomarker that correlates with CF severity, (ii) we provided a method to easily assess this biomarker, and (iii) we carried out the first longitudinal analysis of DNA methylation in CF patients. This new epigenetic biomarker could be used to stratify CF patients in clinical trials.

PMID:33808877 | DOI:10.3390/genes12030441

Antioxidants (Basel). 2021 Mar 19;10(3):483. doi: 10.3390/antiox10030483.

ABSTRACT

RATIONALE: Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, leads to impaired pancreatic function and therefore reduced intestinal absorption of lipids and fat-soluble vitamins especially in patients with CF developing pancreatic insufficiency (PI). Previous studies showed that CFTR modulator therapy with lumacaftor-ivacaftor (LUM/IVA) in Phe508del-homozygous patients with CF results in improvement of pulmonary disease and thriving. However, the effects of LUM/IVA on plasma concentration of the lipid soluble vitamins A and E remain unknown.

OBJECTIVES: To investigate the course of plasma vitamin A and E in patients with CF under LUM/IVA therapy.

METHODS: Data from annual follow-up examinations of patients with CF were obtained to assess clinical outcomes including pulmonary function status, body mass index (BMI), and clinical chemistry as well as fat-soluble vitamins in Phe508del-homozygous CF patients before initiation and during LUM/IVA therapy.

RESULTS: Patients with CF receiving LUM/IVA improved substantially, including improvement in pulmonary inflammation, associated with a decrease in blood immunoglobulin G (IgG) from 9.4 to 8.2 g/L after two years (p < 0.001). During the same time, plasma vitamin A increased significantly from 1.2 to 1.6 µmol/L (p < 0.05), however, levels above the upper limit of normal were not detected in any of the patients. In contrast, plasma vitamin E as vitamin E/cholesterol ratio decreased moderately over the same time from 6.2 to 5.5 µmol/L (p < 0.01).

CONCLUSIONS: CFTR modulator therapy with LUM/IVA alters concentrations of vitamins A and vitamin E in plasma. The increase of vitamin A must be monitored critically to avoid hypervitaminosis A in patients with CF.

PMID:33808590 | DOI:10.3390/antiox10030483

J Clin Med. 2021 Mar 19;10(6):1275. doi: 10.3390/jcm10061275.

ABSTRACT

Most cystic fibrosis (CF) patients referred for lung transplantation are chronically infected with Gram-negative opportunistic pathogens. It is well known that chronic infections in CF patients have a significant impact on lung-function decline and survival before transplantation. The rate and timing of re-colonization after transplantation have been described, but the impact on survival after stratification of bacteria is not well elucidated. We did a single-center retrospective analysis of 99 consecutive CF patients who underwent lung transplantation since the beginning of the Copenhagen Lung Transplant program in 1992 until October 2014. Two patients were excluded due to re-transplantation. From the time of CF diagnosis, patients had monthly sputum cultures. After transplantation, CF-patients had bronchoscopy with bronchoalveolar lavage at 2, 4, 6 and 12 weeks and 6, 12, 18 and 24 months after transplantation, as well as sputum samples if relevant. Selected culture results prior to and after transplantation were stored. We focused on colonization with the most frequent bacteria: Pseudomonas aeruginosa (PA), Stenotrophomonas maltophilia (SM), Achromobacter xylosoxidans (AX) and Burkholderia cepacia complex (BCC). Pulsed-field gel electrophoresis (PFGE) was used to identify clonality of bacterial isolates obtained before and after lung transplantation. Time to re-colonization was defined as the time from transplantation to the first positive culture with the same species. Seventy-three out of 97 (75%) had sufficient culture data for analyses with a median of 7 (1-91) cultures available before and after transplantation. Median colonization-free survival time was 23 days until the first positive culture after transplantation. After 2 years, 59 patients (81%) were re-colonized, 33 (48.5%) with PA, 7 (10.3%) with SM, 12 (17.6%) with AX, and 7 (10.3%) with BCC. No difference in survival was observed between the patients colonized within the first 2 years and those not colonized. Re-colonization of bacteria in the lower airways occurred at a median of 23 days after transplantation in our cohort. In our patient cohort, survival was not influenced by re-colonization or bacterial species.

PMID:33808547 | DOI:10.3390/jcm10061275

Int J Neonatal Screen. 2021 Mar 5;7(1):15. doi: 10.3390/ijns7010015.

ABSTRACT

Neonatal screening (NBS) was initiated in Europe during the 1960s with the screening for phenylketonuria. The panel of screened disorders ("conditions") then gradually expanded, with a boost in the late 1990s with the introduction of tandem mass spectrometry (MS/MS), making it possible to screen for 40-50 conditions using a single blood spot. The most recent additions to screening programmes (screening for cystic fibrosis, severe combined immunodeficiency and spinal muscular atrophy) were assisted by or realised through the introduction of molecular technologies. For this survey, we collected data from 51 European countries. We report the developments between 2010 and 2020 and highlight the achievements reached with the progress made in this period. We also identify areas where further progress can be made, mainly by exchanging knowledge and learning from experiences in neighbouring countries. Between 2010 and 2020, most NBS programmes in geographical Europe matured considerably, both in terms of methodology (modernised) and with regard to the panel of conditions screened (expanded). These developments indicate that more collaboration in Europe through European organisations is gaining momentum. We can only accomplish the timely detection of newborn infants potentially suffering from one of the many rare diseases and take appropriate action by working together.

PMID:33808002 | DOI:10.3390/ijns7010015

Int J Mol Sci. 2021 Mar 5;22(5):2631. doi: 10.3390/ijms22052631.

ABSTRACT

Two siblings with CF are homozygous for F508del (referred to as Subject A and Subject B). Despite having the same CFTR genotype and similar environment, these two subjects exhibited different disease phenotypes. We analyzed their medical records and CF Foundation Registry data and measured inflammatory protein mediators in their sputum samples. Then, we examined the longitudinal relationships between inflammatory markers and disease severity for each subject and compared between them. Subject A presented a more severe disease than Subject B. During the study period, Subject A had two pulmonary exacerbations (PEs) whereas Subject B had one mild PE. The forced expiratory volume in 1 s (FEV1, % predicted) values for Subject A were between 34-45% whereas for Subject B varied between 48-90%. Inflammatory protein mediators associated with neutrophils, Th1, Th2, and Th17 responses were elevated in sputum of Subject A compared with Subject B, and also in samples collected prior to and during PEs for both subjects. Neutrophilic elastase (NE) seemed to be the most informative biomarkers. The infectious burden between these two subjects was different.

PMID:33807880 | DOI:10.3390/ijms22052631

Int J Mol Sci. 2021 Mar 5;22(5):2599. doi: 10.3390/ijms22052599.

ABSTRACT

About 8% of the human genome is covered with candidate cis-regulatory elements (cCREs). Disruptions of CREs, described as "cis-ruptions" have been identified as being involved in various genetic diseases. Thanks to the development of chromatin conformation study techniques, several long-range cystic fibrosis transmembrane conductance regulator (CFTR) regulatory elements were identified, but the regulatory mechanisms of the CFTR gene have yet to be fully elucidated. The aim of this work is to improve our knowledge of the CFTR gene regulation, and to identity factors that could impact the CFTR gene expression, and potentially account for the variability of the clinical presentation of cystic fibrosis as well as CFTR-related disorders. Here, we apply the robust GWAS3D score to determine which of the CFTR introns could be involved in gene regulation. This approach highlights four particular CFTR introns of interest. Using reporter gene constructs in intestinal cells, we show that two new introns display strong cooperative effects in intestinal cells. Chromatin immunoprecipitation analyses further demonstrate fixation of transcription factors network. These results provide new insights into our understanding of the CFTR gene regulation and allow us to suggest a 3D CFTR locus structure in intestinal cells. A better understand of regulation mechanisms of the CFTR gene could elucidate cases of patients where the phenotype is not yet explained by the genotype. This would thus help in better diagnosis and therefore better management. These cis-acting regions may be a therapeutic challenge that could lead to the development of specific molecules capable of modulating gene expression in the future.

PMID:33807548 | DOI:10.3390/ijms22052599

Biomolecules. 2021 Mar 31;11(4):520. doi: 10.3390/biom11040520.

ABSTRACT

BACKGROUND: Cystic fibrosis-related diabetes (CFRD) has become more common due to higher life expectancy with cystic fibrosis. Early recognition and prompt treatment of CFRD leads to improved outcomes.

METHODS: We performed a network meta-analysis (NMA) in order to identify the most valuable diagnostic metrics for diagnosing CFRD out of available screening tools (index test), using the oral glucose tolerance test as a reference standard. Pooled sensitivity (Se), specificity (Sp), and superiority indices were calculated and used to rank the index tests.

RESULTS: A total of 31 articles with 25 index tests were eligible for inclusion. Two-day, continuous glucose monitoring (CGM) ranked the highest (Se: 86% Sp: 76%), followed by glucose measurement from blood capillary samples (Se: 70%, Sp: 82%) and three-day CGM (Se: 96%, Sp: 56%). When we compared the CGM of different durations, two-day CGM performed best (Se: 88%, Sp: 80%), followed by three-day (Se: 96%, Sp: 59%) and six-day CGM (Se: 66%, Sp: 79%).

CONCLUSIONS: Considering its overall performance ranking, as well as the high sensitivity, two-day CGM appears to be a promising screening test for CFRD.

PMID:33807165 | DOI:10.3390/biom11040520

Genes (Basel). 2021 Mar 23;12(3):458. doi: 10.3390/genes12030458.

ABSTRACT

The Robert Debre Pediatric Cystic Fibrosis (CF) centre, located in the North East of Paris, a multicultural area, is in charge of a cohort of around a hundred and sixty children diagnosed with CF. Between 2000 and 2019, the proportion of children of African descent in this centre increased from 2% to 10%. We report the clinical features of 17 children of African descent diagnosed with CF: 4 (23%) were diagnosed after a meconium ileus, 14 (83%) had exocrine pancreatic insufficiency, and 7 (41%) had early Pseudomonas aeruginosa infection before the age of two. Even though the majority of patients were diagnosed through NBS, the twenty-nine-mutation testing kit proved less effective in non-Caucasian populations, with a false negative rate of 25% in this series. CF is definitely not solely a Caucasian disease and the literature reveals similar phenotypes in Caucasian and African people provided that they present the same CFTR mutations. Clinicians have to keep in mind that the diagnosis of CF in patients of African descent must be evoked in the case of symptoms and a sweat test must be performed, despite a negative result for NBS.

PMID:33807078 | DOI:10.3390/genes12030458

Int J Mol Sci. 2021 Mar 25;22(7):3384. doi: 10.3390/ijms22073384.

ABSTRACT

Knowledge on the mechanisms of acid and base secretion in airways has progressed recently. The aim of this review is to summarize the known mechanisms of airway surface liquid (ASL) pH regulation and their implication in lung diseases. Normal ASL is slightly acidic relative to the interstitium, and defects in ASL pH regulation are associated with various respiratory diseases, such as cystic fibrosis. Basolateral bicarbonate (HCO3-) entry occurs via the electrogenic, coupled transport of sodium (Na+) and HCO3-, and, together with carbonic anhydrase enzymatic activity, provides HCO3- for apical secretion. The latter mainly involves CFTR, the apical chloride/bicarbonate exchanger pendrin and paracellular transport. Proton (H+) secretion into ASL is crucial to maintain its relative acidity compared to the blood. This is enabled by H+ apical secretion, mainly involving H+/K+ ATPase and vacuolar H+-ATPase that carry H+ against the electrochemical potential gradient. Paracellular HCO3- transport, the direction of which depends on the ASL pH value, acts as an ASL protective buffering mechanism. How the transepithelial transport of H+ and HCO3- is coordinated to tightly regulate ASL pH remains poorly understood, and should be the focus of new studies.

PMID:33806154 | DOI:10.3390/ijms22073384

Biomolecules. 2021 Mar 13;11(3):422. doi: 10.3390/biom11030422.

ABSTRACT

Cystic fibrosis is a monogenic, autosomal, recessive disease characterized by an alteration of chloride transport caused by mutations in the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene. The loss of Phe residue in position 508 (ΔF508-CFTR) causes an incorrect folding of the protein causing its degradation and electrolyte imbalance. CF patients are extremely predisposed to the development of a chronic inflammatory process of the bronchopulmonary system. When the cells of a tissue are damaged, the immune cells are activated and trigger the production of free radicals, provoking an inflammatory process. In addition to routine therapies, today drugs called correctors are available for mutations such as ΔF508-CFTR as well as for others less frequent ones. These active molecules are supposed to facilitate the maturation of the mutant CFTR protein, allowing it to reach the apical membrane of the epithelial cell. Matrine induces ΔF508-CFTR release from the endoplasmic reticulum to cell cytosol and its localization on the cell membrane. We now have evidence that Matrine and Lumacaftor not only restore the transport of mutant CFTR protein, but probably also counteract the inflammatory process by improving the course of the disease.

PMID:33805605 | DOI:10.3390/biom11030422

Biology (Basel). 2021 Mar 29;10(4):278. doi: 10.3390/biology10040278.

ABSTRACT

Cystic fibrosis (CF) is a genetic disease associated with the defective function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein that causes obstructive disease and chronic bacterial infections in airway epithelia. Deletion of phenylalanine at position 508, p.F508del, the most frequent mutation among CF patients, causes a folding and traffic defect, resulting in a dramatic reduction in the CFTR expression. To investigate whether the direct application of bicarbonate could modify the properties of the airway surface liquid (ASL), we measured the micro-viscosity, fluid transport and pH of human bronchial epithelial cells monolayers. We have demonstrated that the treatment of a CF-epithelia with an iso-osmotic solution containing bicarbonate is capable of reducing both, the ASL viscosity and the apical fluid re-absorption. We suggest the possibility of design a supportive treatment based on topical application of bicarbonate, or any other alkaline buffer.

PMID:33805545 | DOI:10.3390/biology10040278

Pathogens. 2021 Mar 29;10(4):401. doi: 10.3390/pathogens10040401.

ABSTRACT

The opportunistic human pathogen Pseudomonas aeruginosa is responsible for a variety of acute infections and is a major cause of mortality in chronically infected cystic fibrosis patients. Due to increased resistance to antibiotics, new therapeutic strategies against P. aeruginosa are urgently needed. In this context, we aimed to develop a simple vertebrate animal model to rapidly assess in vivo drug efficacy against P. aeruginosa. Zebrafish are increasingly considered for modeling human infections caused by bacterial pathogens, which are commonly microinjected in embryos. In the present study, we established a novel protocol for zebrafish infection by P. aeruginosa based on bath immersion in 96-well plates of tail-injured embryos. The immersion method, followed by a 48-hour survey of embryo viability, was first validated to assess the virulence of P. aeruginosa wild-type PAO1 and a known attenuated mutant. We then validated its relevance for antipseudomonal drug testing by first using a clinically used antibiotic, ciprofloxacin. Secondly, we used a novel quorum sensing (QS) inhibitory molecule, N-(2-pyrimidyl)butanamide (C11), the activity of which had been validated in vitro but not previously tested in any animal model. A significant protective effect of C11 was observed on infected embryos, supporting the ability of C11 to attenuate in vivo P. aeruginosa pathogenicity. In conclusion, we present here a new and reliable method to compare the virulence of P. aeruginosa strains in vivo and to rapidly assess the efficacy of clinically relevant drugs against P. aeruginosa, including new antivirulence compounds.

PMID:33805384 | DOI:10.3390/pathogens10040401

Biomedicines. 2021 Mar 24;9(4):329. doi: 10.3390/biomedicines9040329.

ABSTRACT

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF Transmembrane Conductance Regulator (CFTR), an apical chloride channel. An early inflammation (EI) in the lung of CF patients occurring in the absence of any bacterial infection has been reported. This EI has been proposed to be associated with oxidative stress (OX-S), generated by deregulations of the oxidant/antioxidant status. Recently, we demonstrated that copper (Cu), an essential trace element, mediates OX-S in bronchial cells. However, the role of this element in the development of CF-EI, in association with OX-S, has never been investigated. Using healthy (16HBE14o-; HBE), CF (CFBE14o-; CFBE), and corrected-wild type CFTR CF (CFBE-wt) bronchial cells, we characterized the inflammation and OX-S profiles in relation to the copper status and CFTR expression and function. We demonstrated that CFBE cells exhibited a CFTR-independent intrinsic inflammation. These cells also exhibited an alteration in mitochondria, UPR (Unfolded Protein Response), catalase, Cu/Zn- and Mn-SOD activities, and an increase in the intracellular content of iron, zinc, and Cu. The increase in Cu concentration was associated with OX-S and inflammatory responses. These data identify cellular Cu as a key factor in the generation of CF-associated OX-S and opens new areas of investigation to better understand CF-associated EI.

PMID:33805052 | DOI:10.3390/biomedicines9040329