BMJ Open Respir Res. 2023 May;10(1):e001309. doi: 10.1136/bmjresp-2022-001309.

ABSTRACT

INTRODUCTION: Dynamic chest radiography (DCR) is a novel, low-dose, real-time digital imaging system where software identifies moving thoracic structures and can automatically calculate lung areas. In an observational, prospective, non-controlled, single-centre pilot study, we compared it with whole-body plethysmography (WBP) in the measurement of lung volume subdivisions in people with cystic fibrosis (pwCF).

METHODS: Lung volume subdivisions were estimated by DCR using projected lung area (PLA) during deep inspiration, tidal breathing and full expiration, and compared with same-day WBP in 20 adult pwCF attending routine review. Linear regression models to predict lung volumes from PLA were developed.

RESULTS: Total lung area (PLA at maximum inspiration) correlated with total lung capacity (TLC) (r=0.78, p<0.001), functional residual lung area with functional residual capacity (FRC) (r=0.91, p<0.001), residual lung area with residual volume (RV) (r=0.82, p=0.001) and inspiratory lung area with inspiratory capacity (r=0.72, p=0.001). Despite the small sample size, accurate models were developed for predicting TLC, RV and FRC.

CONCLUSION: DCR is a promising new technology that can be used to estimate lung volume subdivisions. Plausible correlations between plethysmographic lung volumes and DCR lung areas were identified. Further studies are needed to build on this exploratory work in both pwCF and individuals without CF.

TRIAL REGISTRATION NUMBER: ISRCTN64994816.

PMID:37147023 | DOI:10.1136/bmjresp-2022-001309

J Sep Sci. 2023 May 5:e2201061. doi: 10.1002/jssc.202201061. Online ahead of print.

ABSTRACT

Cystic fibrosis is a life-threatening genetic disease that causes damage to the lungs. Ivacaftor, the first drug to target the underlying defect of the disease caused by specific mutations, improves outcomes and reduces hospitalizations. In this study, quantitative determination of ivacaftor was performed by LC, while high-resolution mass spectrometric analyses were performed for qualitative determination. The validation studies of the developed methods were performed according to International Conference on Harmonisation Q2(R1) guideline. Ivacaftor was separated from its degradation product by using Phenomenex Kinetex® C18 (150 × 3 mm, 2.6 μm) column. The isocratic mobile phase for binary pump configuration was 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in acetonitrile (27:63) (v/v), pH = 2.5; the flow rate of 0.25 mL/min was used in all methods. In the degradation studies, five degradation products were identified using high-performance liquid chromatography ion trap time-of-flight mass spectrometric analyses: Three of them have never been reported up to date; whereas the other two were existing in the literature and they were having Chemical Abstracts Services registry numbers since they were synthesized before for various other purposes. Also, analysis of an in-lab prepared chemical equivalent of Kalydeco® and interlaboratory comparison were performed. This article is protected by copyright. All rights reserved.

PMID:37146100 | DOI:10.1002/jssc.202201061

PLoS One. 2023 May 5;18(5):e0284511. doi: 10.1371/journal.pone.0284511. eCollection 2023.

ABSTRACT

BACKGROUND: Objective monitoring of improvement during treatment of pulmonary exacerbation can be difficulty in children when pulmonary function testing cannot be obtained. Thus, the identification of predictive biomarkers to determine the efficacy of drug treatments is of high priority. The major aim of the current study was to investigate the serum levels of vasoactive intestinal peptide (VIP) and alpha calcitonin gene related peptide (aCGRP) of cystic fibrosis pediatric patients during pulmonary exacerbation and post-antibiotic therapy, and possible associations of their levels with different clinicopathological parameters.

METHODS: 21 patients with cystic fibrosis were recruited at onset of pulmonary exacerbation. Serum was collected at time of admission, three days post-antibiotic therapy, and two weeks post-antibiotic therapy (end of antibiotic therapy). Serum VIP and aCGRP levels were measured using ELISA.

RESULTS: Overall least square means of serum aCGRP level but not VIP changed from time of exacerbation to completion of antibiotic therapy (p = 0.005). Serum VIP was significantly associated with the presence of diabetes mellitus (p = 0.026) and other comorbidities (p = 0.013), and with type of antibiotic therapy (p = 0.019). Serum aCGRP level was significantly associated with type of antibiotic therapy (p = 0.012) and positive Staphylococcus aureus microbiology test (p = 0.046).

CONCLUSION: This study could only show significant changes in serum aCGRP levels following treatment of pulmonary exacerbations. Future studies with larger sample size are required to investigate the clinical importance of VIP and aCGRP in cystic fibrosis patients.

PMID:37146001 | DOI:10.1371/journal.pone.0284511

Pediatr Pulmonol. 2023 May 5. doi: 10.1002/ppul.26452. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the validity and reliability of the modified shuttle 25-level test (MST-25) in children with cystic fibrosis (CF).

METHODS: A prospective single center study in clinically stable children with CF. Participants undertook two testing conditions on different days: (1) 2xMST-25 tests; (2) cardiopulmonary exercise test (CPET). Test order was randomized. Nadir oxygen saturation (SpO2 ), peak heart rate (HR), breathlessness (modified Borg), rate of perceived exertion (RPE), energy expenditure (EE) and metabolic equivalents (MET) from the MST-25 and CPET were compared to assess validity, while outcomes from 2xMST-25 tests were compared for reliability. CPET was performed using breath-by-breath analysis and EE from the MST-25 obtained using the SenseWear Armband.

RESULTS: Strong correlations were found between MST-25 distance and peak oxygen uptake, peak work and minute ventilation on CPET (all r > 0.7, p < 0.01). Moderate correlations were found between MST-25 distance and CPET for METs (r = 0.5) and HR (r = 0.6). Weak associations between tests were evident for nadir SpO2 (r = 0.1), modified Borg (rs = 0.2) and RPE (rs = 0.2). Test-retest reliability was excellent for MST-25 distance (ICC 0.91), peak EE (ICC 0.99) and peak METs (ICC 0.90). Good reliability was achieved for HR (ICC 0.84) and modified Borg score (ICC 0.77), while moderate reliability for nadir SpO2 (ICC 0.64) and RPE (ICC 0.68) was observed.

CONCLUSION: The MST-25 is a valid and reliable field test for the assessment of exercise capacity in children with CF. The MST-25 can be used to accurately monitor exercise capacity and prescribe exercise training, particularly when CPET is not available.

PMID:37144876 | DOI:10.1002/ppul.26452

Pediatr Pulmonol. 2023 May 5. doi: 10.1002/ppul.26438. Online ahead of print.

ABSTRACT

BACKGROUND: eHealth CF-CBT is the first digital mental health intervention for depression/anxiety in adults with cystic fibrosis (awCF); an 8-session therapist-guided internet-delivered program that was developed in English and Dutch with stakeholder input and evaluation indicating high acceptability and usability.

METHODS: Dutch eHealth CF-CBT was piloted in awCF with mild-moderate symptoms of depression and/or anxiety. Feasibility, usability, acceptability, and preliminary efficacy were assessed, measuring pre-post changes in depression (PHQ-9), anxiety (GAD-7), perceived stress (PSS), and health-related quality of life (CFQ-R).

RESULTS: All participants (n = 10, seven female, mean age 29 [range 21-43], mean FEV1 71%pred [range 31-115]) completed all sessions. Patient-rated feasibility, usability, and acceptability of eHealth CF-CBT were positive on validated scales, as were qualitative assessments of content and format. GAD-7 improved in 90% of participants; in 50% by ≥the minimally important difference (MID) of four points. PHQ-9 improved in 90%; 40% by ≥the MID of 5. PSS improved in 80%. CFQ-R improved in the domain health perceptions (70%).

CONCLUSIONS: eHealth CF-CBT demonstrated feasibility, usability, acceptability, and promising preliminary efficacy in this pilot trial with Dutch awCF with mild to moderate symptoms of depression and anxiety.

PMID:37144856 | DOI:10.1002/ppul.26438

Cochrane Database Syst Rev. 2023 May 5;5:CD002011. doi: 10.1002/14651858.CD002011.pub3.

ABSTRACT

BACKGROUND: Cystic fibrosis (CF) is an inherited life-limiting disorder. Over time persistent infection and inflammation within the lungs contribute to severe airway damage and loss of respiratory function. Chest physiotherapy, or airway clearance techniques (ACTs), are integral in removing airway secretions and initiated shortly after CF diagnosis. Conventional chest physiotherapy (CCPT) generally requires assistance, while alternative ACTs can be self-administered, facilitating independence and flexibility. This is an updated review.

OBJECTIVES: To evaluate the effectiveness (in terms of respiratory function, respiratory exacerbations, exercise capacity) and acceptability (in terms of individual preference, adherence, quality of life) of CCPT for people with CF compared to alternative ACTs.

SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was 26 June 2022.

SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials (including cross-over design) lasting at least seven days and comparing CCPT with alternative ACTs in people with CF.

DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. pulmonary function tests and 2. number of respiratory exacerbations per year. Our secondary outcomes were 3. quality of life, 4. adherence to therapy, 5. cost-benefit analysis, 6. objective change in exercise capacity, 7. additional lung function tests, 8. ventilation scanning, 9. blood oxygen levels, 10. nutritional status, 11. mortality, 12. mucus transport rate and 13. mucus wet or dry weight. We reported outcomes as short-term (seven to 20 days), medium-term (more than 20 days to up to one year) and long-term (over one year).

MAIN RESULTS: We included 21 studies (778 participants) comprising seven short-term, eight medium-term and six long-term studies. Studies were conducted in the USA (10), Canada (five), Australia (two), the UK (two), Denmark (one) and Italy (one) with a median of 23 participants per study (range 13 to 166). Participant ages ranged from newborns to 45 years; most studies only recruited children and young people. Sixteen studies reported the sex of participants (375 males; 296 females). Most studies compared modifications of CCPT with a single comparator, but two studies compared three interventions and another compared four interventions. The interventions varied in the duration of treatments, times per day and periods of comparison making meta-analysis challenging. All evidence was very low certainty. Nineteen studies reported the primary outcomes forced expiratory volume in one second (FEV1)and forced vital capacity (FVC), and found no difference in change from baseline in FEV1 % predicted or rate of decline between groups for either measure. Most studies suggested equivalence between CCPT and alternative ACTs, including positive expiratory pressure (PEP), extrapulmonary mechanical percussion, active cycle of breathing technique (ACBT), oscillating PEP devices (O-PEP), autogenic drainage (AD) and exercise. Where single studies suggested superiority of one ACT, these findings were not corroborated in similar studies; pooled data generally concluded that effects of CCPT were comparable to those of alternative ACTs. CCPT versus PEP We are uncertain whether CCPT improves lung function or has an impact on the number of respiratory exacerbations per year compared with PEP (both very low-certainty evidence). There were no analysable data for our secondary outcomes, but many studies provided favourable narrative reports on the independence achieved with PEP mask therapy. CCPT versus extrapulmonary mechanical percussion We are uncertain whether CCPT improves lung function compared with extrapulmonary mechanical percussions (very low-certainty evidence). The annual rate of decline in average forced expiratory flow between 25% and 75% of FVC (FEF25-75) was greater with high-frequency chest compression compared to CCPT in medium- to long-term studies, but there was no difference in any other outcome. CCPT versus ACBT We are uncertain whether CCPT improves lung function compared to ACBT (very low-certainty evidence). Annual decline in FEF25-75 was worse in participants using the FET component of ACBT only (mean difference (MD) 6.00, 95% confidence interval (CI) 0.55 to 11.45; 1 study, 63 participants; very low-certainty evidence). One short-term study reported that directed coughing was as effective as CCPT for all lung function outcomes, but with no analysable data. One study found no difference in hospital admissions and days in hospital for exacerbations. CCPT versus O-PEP We are uncertain whether CCPT improves lung function compared to O-PEP devices (Flutter device and intrapulmonary percussive ventilation); however, only one study provided analysable data (very low-certainty evidence). No study reported data for number of exacerbations. There was no difference in results for number of days in hospital for an exacerbation, number of hospital admissions and number of days of intravenous antibiotics; this was also true for other secondary outcomes. CCPT versus AD We are uncertain whether CCPT improves lung function compared to AD (very low-certainty evidence). No studies reported the number of exacerbations per year; however, one study reported more hospital admissions for exacerbations in the CCPT group (MD 0.24, 95% CI 0.06 to 0.42; 33 participants). One study provided a narrative report of a preference for AD. CCPT versus exercise We are uncertain whether CCPT improves lung function compared to exercise (very low-certainty evidence). Analysis of original data from one study demonstrated a higher FEV1 % predicted (MD 7.05, 95% CI 3.15 to 10.95; P = 0.0004), FVC (MD 7.83, 95% CI 2.48 to 13.18; P = 0.004) and FEF25-75 (MD 7.05, 95% CI 3.15 to 10.95; P = 0.0004) in the CCPT group; however, the study reported no difference between groups (likely because the original analysis accounted for baseline differences).

AUTHORS' CONCLUSIONS: We are uncertain whether CCPT has a more positive impact on respiratory function, respiratory exacerbations, individual preference, adherence, quality of life, exercise capacity and other outcomes when compared to alternative ACTs as the certainty of the evidence is very low. There was no advantage in respiratory function of CCPT over alternative ACTs, but this may reflect insufficient evidence rather than real equivalence. Narrative reports indicated that participants prefer self-administered ACTs. This review is limited by a paucity of well-designed, adequately powered, long-term studies. This review cannot yet recommend any single ACT above others; physiotherapists and people with CF may wish to try different ACTs until they find an ACT that suits them best.

PMID:37144842 | DOI:10.1002/14651858.CD002011.pub3

Curr Opin Organ Transplant. 2023 Jun 1;28(3):188-191. doi: 10.1097/MOT.0000000000001061.

NO ABSTRACT

PMID:37144815 | DOI:10.1097/MOT.0000000000001061

ERJ Open Res. 2023 May 2;9(3):00737-2022. doi: 10.1183/23120541.00737-2022. eCollection 2023 Jul.

ABSTRACT

BACKGROUND: Certain patients are at greater risk of developing nontuberculous mycobacterial pulmonary disease (NTM-PD), including those with lung conditions such as bronchiectasis. Testing for nontuberculous mycobacteria (NTM) in patients at risk is necessary to identify NTM-PD and start appropriate management. The aim of this survey was to evaluate current testing practices for NTM and identify testing triggers.

METHODS: Physicians (n=455) who see at least one patient with NTM-PD in a typical 12-month period and test for NTM as part of practice from Europe, USA, Canada, Australia, New Zealand and Japan participated in a 10-min anonymised survey on NTM testing practices.

RESULTS: Bronchiectasis, COPD and use of immunosuppressants were the factors most likely to prompt testing among physicians in this survey (90%, 64% and 64%, respectively), with radiological findings the most common reason leading to considering NTM testing in patients with bronchiectasis and COPD (62% and 74%, respectively). Macrolide monotherapy in patients with bronchiectasis and inhaled corticosteroid use in patients with COPD were not important triggers for testing (15% and 9% of physicians, respectively). Persistent cough and weight loss triggered testing in >75% of physicians. Testing triggers were markedly different for physicians in Japan, with cystic fibrosis prompting testing in fewer physicians compared with other regions.

CONCLUSIONS: Testing for NTM is influenced by underlying disease, clinical symptoms or radiological changes, but clinical practice varies considerably. Adherence to guideline recommendations for NTM testing is limited in certain patient subgroups and varies across regions. Clear recommendations on NTM testing are needed.

PMID:37143838 | PMC:PMC10152245 | DOI:10.1183/23120541.00737-2022

ERJ Open Res. 2023 May 2;9(3):00712-2022. doi: 10.1183/23120541.00712-2022. eCollection 2023 Jul.

ABSTRACT

Bronchiectasis is a chronic, progressive lung disease believed to result from a vicious cycle of infection and inflammation, with symptoms of chronic cough with sputum production, chronic fatigue, rhinosinusitis, chest pain, breathlessness and haemoptysis. There are currently no established instruments to monitor daily symptoms and exacerbations for use in clinical trials. Following a literature review and three expert clinician interviews, we conducted concept elicitation interviews with 20 patients with bronchiectasis to understand their personal disease experience. Findings from literature and clinician feedback were used to develop a draft version of the Bronchiectasis Exacerbation Diary (BED), which was designed to monitor key symptoms on a daily basis and during exacerbations. Patients were eligible to be interviewed if they were US residents aged ≥18 years, had a computed tomography scan-confirmed diagnosis of bronchiectasis with ≥two exacerbations in the previous 2 years and had no other uncontrolled respiratory conditions. Four waves of five patient interviews each were conducted. Patients (n=20) had a mean±SD age of 53.9±12.8 years, and most were female (85%) and white (85%). A total of 33 symptoms and 23 impacts arose from the patient concept elicitation interviews. The BED was revised and finalised based upon patient feedback. The final BED is a novel, eight-item patient-reported outcome (PRO) instrument for monitoring key exacerbation symptoms on a daily basis with content validity established through comprehensive qualitative research and direct patient insight. The BED PRO development framework will be completed following psychometric evaluations of the data from a phase 3 bronchiectasis clinical trial.

PMID:37143836 | PMC:PMC10152244 | DOI:10.1183/23120541.00712-2022

ERJ Open Res. 2023 May 2;9(3):00695-2022. doi: 10.1183/23120541.00695-2022. eCollection 2023 Jul.

ABSTRACT

Brensocatib is a novel anti-inflammatory therapy in development for bronchiectasis treatment. Phase 2 WILLOW trial data demonstrate a low number needed to treat and negative number needed to harm, suggesting a favourable benefit-risk profile. https://bit.ly/3SbisW3.

PMID:37143828 | PMC:PMC10152260 | DOI:10.1183/23120541.00695-2022

J Natl Cancer Inst Monogr. 2023 May 4;2023(61):12-29. doi: 10.1093/jncimonographs/lgad014.

ABSTRACT

The obesity pandemic currently affects more than 70 million Americans and more than 650 million individuals worldwide. In addition to increasing susceptibility to pathogenic infections (eg, SARS-CoV-2), obesity promotes the development of many cancer subtypes and increases mortality rates in most cases. We and others have demonstrated that, in the context of B-cell acute lymphoblastic leukemia (B-ALL), adipocytes promote multidrug chemoresistance. Furthermore, others have demonstrated that B-ALL cells exposed to the adipocyte secretome alter their metabolic states to circumvent chemotherapy-mediated cytotoxicity. To better understand how adipocytes impact the function of human B-ALL cells, we used a multi-omic RNA-sequencing (single-cell and bulk transcriptomic) and mass spectroscopy (metabolomic and proteomic) approaches to define adipocyte-induced changes in normal and malignant B cells. These analyses revealed that the adipocyte secretome directly modulates programs in human B-ALL cells associated with metabolism, protection from oxidative stress, increased survival, B-cell development, and drivers of chemoresistance. Single-cell RNA sequencing analysis of mice on low- and high-fat diets revealed that obesity suppresses an immunologically active B-cell subpopulation and that the loss of this transcriptomic signature in patients with B-ALL is associated with poor survival outcomes. Analyses of sera and plasma samples from healthy donors and those with B-ALL revealed that obesity is associated with higher circulating levels of immunoglobulin-associated proteins, which support observations in obese mice of altered immunological homeostasis. In all, our multi-omics approach increases our understanding of pathways that may promote chemoresistance in human B-ALL and highlight a novel B-cell-specific signature in patients associated with survival outcomes.

PMID:37139973 | PMC:PMC10157791 | DOI:10.1093/jncimonographs/lgad014

Eur Respir J. 2023 May 4:2202053. doi: 10.1183/13993003.02053-2022. Online ahead of print.

ABSTRACT

Airway clearance techniques (ACTs) are part of the main management strategy for patients with bronchiectasis. Despite being a priority for patients, accessibility, implementation, and reporting of ACTs are variable in clinical settings and research studies. This European Respiratory Society statement summarises current knowledge about the ACTs in adults with bronchiectasis and makes recommendations to improve future evidence base. A task force of 14 experts and two patient representatives (10 countries) determined the scope of this statement through consensus and defined six questions. The questions were answered based on systematic searches of the literature.The statement provides a comprehensive review of the physiological rationale for ACTs in adults with bronchiectasis, and the mechanisms of action along with the advantages and disadvantages of each ACT. Evidence on the ACTs in clinical practice indicates that active cycle of breathing techniques, positive expiratory pressure devices and gravity assisted drainage technique are the most frequently used techniques, although there is limited evidence on the type of ACTs used in specific countries. A review of 30 randomised trials for the effectiveness of the ACTs shows that these interventions increase sputum clearance during or after treatment, reduce the impact of cough and the risk of exacerbations, and improve health-related quality of life. Furthermore, strategies for reducing the risk of bias in future studies are proposed. Finally, an exploration of patientś perceptions, barriers and enablers related to this treatment is also included to facilitate implementation and adherence to ACTs.

PMID:37142337 | DOI:10.1183/13993003.02053-2022

Respir Med. 2023 May 2:107262. doi: 10.1016/j.rmed.2023.107262. Online ahead of print.

NO ABSTRACT

PMID:37142165 | DOI:10.1016/j.rmed.2023.107262

J Cyst Fibros. 2023 May 2:S1569-1993(23)00126-1. doi: 10.1016/j.jcf.2023.04.020. Online ahead of print.

ABSTRACT

BACKGROUND: Secondhand smoke exposure, an important environmental health factor in cystic fibrosis (CF), remains uniquely challenging to children with CF as they strive to maintain pulmonary function during early stages of growth and throughout adolescence. Despite various epidemiologic studies among CF populations, little has been done to coalesce estimates of the association between secondhand smoke exposure and lung function decline.

METHODS: A systematic review was performed using PRISMA guidelines. A Bayesian random-effects model was employed to estimate the association between secondhand smoke exposure and change in lung function (measured as FEV1% predicted).

RESULTS: Quantitative synthesis of study estimates indicated that second-hand smoke exposure corresponded to a significant drop in FEV1 (estimated decrease: -5.11% predicted; 95% CI: -7.20, -3.47). The estimate of between-study heterogeneity was 1.32% predicted (95% CI: 0.05, 4.26). There was moderate heterogeneity between the 6 analyzed studies that met review criteria (degree of heterogeneity: I2=61.9% [95% CI: 7.3-84.4%] and p = 0.022 from the frequentist method.) CONCLUSIONS: Our results quantify the impact at the pediatric population level and corroborate the assertion that secondhand smoke exposure negatively affects pulmonary function in children with CF. Findings highlight challenges and opportunities for future environmental health interventions in pediatric CF care.

PMID:37142525 | DOI:10.1016/j.jcf.2023.04.020

J Cyst Fibros. 2023 May 2:S1569-1993(23)00124-8. doi: 10.1016/j.jcf.2023.04.016. Online ahead of print.

NO ABSTRACT

PMID:37142524 | DOI:10.1016/j.jcf.2023.04.016

J Cyst Fibros. 2023 May 2:S1569-1993(23)00125-X. doi: 10.1016/j.jcf.2023.04.019. Online ahead of print.

ABSTRACT

BACKGROUND: Children with cystic fibrosis are at risk of fat-soluble vitamin deficiency. CFTR modulators positively effect nutritional status. This study aimed to assess changes in serum vitamins A, D & E after starting ETI therapy to ensure levels were not abnormally high.

METHODS: Retrospective review of annual assessment data over 3½ years, before and after starting ETI in a specialist paediatric CF centre, including vitamin levels.

RESULTS: 54 eligible patients were included, aged 5-15 yrs (median age 11.5). Median time to post measurements was 171 days. Median vitamin A was increased (1.38 to 1.63 µmol/L, p<0.001). Three patients (6%) had high vitamin A post-ETI, compared with none at baseline; and 2 (4%) had low levels compared to 4 (8%) at baseline. No changes in vitamins D&E.

CONCLUSIONS: This study found increased vitamin A, sometimes to high levels. We recommend testing levels within 3 months of starting ETI.

PMID:37142523 | DOI:10.1016/j.jcf.2023.04.019

J Cyst Fibros. 2023 May 2:S1569-1993(23)00127-3. doi: 10.1016/j.jcf.2023.04.021. Online ahead of print.

ABSTRACT

BACKGROUND: A largely unexplored area of research is the identification and characterization of circular RNA (circRNA) in cystic fibrosis (CF). This study is the first to identify and characterize alterations in circRNA expression in cells lacking CFTR function. The circRNA expression profiles in whole blood transcriptomes from CF patients homozygous for the pathogenetic variant F508delCFTR are compared to healthy controls.

METHODS: We developed a circRNA pipeline called circRNAFlow utilizing Nextflow. Whole blood transcriptomes from CF patients homozygous for the F508delCFTR-variant and healthy controls were utilized as input to circRNAFlow to discover dysregulated circRNA expression in CF samples compared to wild-type controls. Pathway enrichment analyzes were performed to investigate potential functions of dysregulated circRNAs in whole blood transcriptomes from CF samples compared to wild-type controls.

RESULTS: A total of 118 dysregulated circRNAs were discovered in whole blood transcriptomes from CF patients homozygous for the F508delCFTR variant compared to healthy controls. 33 circRNAs were up regulated whilst 85 circRNAs were down regulated in CF samples compared to healthy controls. The overrepresented pathways of the host genes harboring dysregulated circRNA in CF samples compared to controls include positive regulation of responses to endoplasmic reticulum stress, intracellular transport, protein serine/threonine kinase activity, phospholipid-translocating ATPase complex, ferroptosis and cellular senescence. These enriched pathways corroborate the role of dysregulated cellular senescence in CF.

CONCLUSION: This study highlights the underexplored roles of circRNAs in CF with a perspective to provide a more complete molecular characterization of CF.

PMID:37142522 | DOI:10.1016/j.jcf.2023.04.021

Am J Respir Cell Mol Biol. 2023 May 4. doi: 10.1165/rcmb.2022-0280OC. Online ahead of print.

ABSTRACT

Pulmonary ionocytes express high levels of cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel critical for hydration of the airways and mucociliary clearance. However, the cellular mechanisms that govern ionocyte specification and function remain unclear. We observed that increased abundance of ionocytes in cystic fibrosis (CF) airway epithelium was associated with enhanced expression of Sonic Hedgehog (SHH) effectors. In this study, we evaluated whether the SHH pathway directly impacts ionocyte differentiation and CFTR function in airway epithelia. Pharmacological HPI1-mediated inhibition of SHH signaling component GLI1 significantly impaired human basal cell specification of ionocytes and ciliated cells, but significant enhanced specification of secretory cells. By contrast, activation of the SHH pathway effector SMO with the chemical agonist SAG significantly enhanced ionocyte specification. The abundance of CFTR+BSND+ ionocytes under these conditions had a direct relationship with CFTR-mediated currents in differentiated air-liquid interface (ALI) airway cultures. These findings were corroborated in ferret ALI airway cultures generated from basal cells in which the genes encoding the SHH receptor PTCH1 or its intracellular effector SMO were genetically ablated using CRISPR/Cas9, causing aberrant activation or suppression of SHH signaling, respectively. These findings demonstrate that SHH signaling is directly involved in airway basal cell specification of CFTR-expressing pulmonary ionocytes and likely responsible for enhanced ionocyte abundance in the CF proximal airways. Pharmacologic approaches to enhance ionocyte and reduce secretory cell specification following CFTR gene editing of basal cells may have utility in the treatment of CF.

PMID:37141531 | DOI:10.1165/rcmb.2022-0280OC

Daru. 2023 May 4. doi: 10.1007/s40199-023-00460-4. Online ahead of print.

ABSTRACT

BACKGROUND: Cystic fibrosis is a severe, autosomal recessive disease that shortens life expectancy. According to studies, approximately 27% of patients with CF aged 2-5 years and 60 to 70% of adult patients are infected with P. aeruginosa. The patients experience bronchospasm leading to a persistent contracted state of the airways.

OBJECTIVES: The current work explores the possibility of combining ivacaftor and ciprofloxacin to combat the bacteria. A third drug L-salbutamol would be coated onto the surface of the drug-entrappped microparticles to instantaneously provide relief from bronchoconstriction.

METHODS: The microparticles were prepared using bovine serum albumin and L-leucine using the freeze-drying approach. The process and formulation parameters were optimized. The prepared microparticles were surface coated by L-salbutamol using the dry-blending method. The microparticles were subjected to rigorous in-vitro characterization for entrapment, inhalability, antimicrobial activity, cytotoxicity study and safety. The performance of the microparticles to be loaded into a inhaler was checked by the Anderson cascade impactor.

RESULTS: The freeze-dried microparticles had a particle size of 817.5 ± 5.6 nm with a polydispersity ratio of 0.33. They had a zeta potential of -23.3 ± 1.1 mV. The mass median aerodynamic diameter of the microparticles was 3.75 ± 0.07 μm, and the geometric standard diameter was 1.66 ± 0.033 μm. The microparticles showed good loading efficiency for all three drugs. DSC, SEM, XRD, and FTIR studies confirmed the entrapment of ivacaftor and ciprofloxacin. SEM and TEM scans observed the shape and the smooth surface. Antimicrobial synergism was proven by the agar broth, and dilution technique and the formulation was deemed safe by the results of the MTT assay.

CONCLUSION: Freeze-dried microparticles of ivacaftor, ciprofloxacin, and L-salbutamol could pave way to a hitherto unexplored combination of drugs as a novel approach to treat P. aeruginosa infcetions and bronchoconstriction commonly associated with cystic fibrosis.

PMID:37140775 | DOI:10.1007/s40199-023-00460-4

Microbiol Spectr. 2023 May 4:e0497022. doi: 10.1128/spectrum.04970-22. Online ahead of print.

ABSTRACT

Clinicians are increasingly confronted with the limitations of antibiotics to clear bacterial infections in patients. It has long been assumed that only antibiotic resistance plays a pivotal role in this phenomenon. Indeed, the worldwide emergence of antibiotic resistance is considered one of the major health threats of the 21st century. However, the presence of persister cells also has a significant influence on treatment outcomes. These antibiotic-tolerant cells are present in every bacterial population and are the result of the phenotypic switching of normal, antibiotic-sensitive cells. Persister cells complicate current antibiotic therapies and contribute to the development of resistance. In the past, extensive research has been performed to investigate persistence in laboratory settings; however, antibiotic tolerance under conditions that mimic the clinical setting remain poorly understood. In this study, we optimized a mouse model for lung infections with the opportunistic pathogen Pseudomonas aeruginosa. In this model, mice are intratracheally infected with P. aeruginosa embedded in seaweed alginate beads and subsequently treated with tobramycin via nasal droplets. A diverse panel of 18 P. aeruginosa strains originating from environmental, human, and animal clinical sources was selected to assess survival in the animal model. Survival levels were positively correlated with the survival levels determined via time-kill assays, a common method to study persistence in the laboratory. We showed that survival levels are comparable and thus that the classical persister assays are indicative of antibiotic tolerance in a clinical setting. The optimized animal model also enables us to test potential antipersister therapies and study persistence in relevant settings. IMPORTANCE The importance of targeting persister cells in antibiotic therapies is becoming more evident, as these antibiotic-tolerant cells underlie relapsing infections and resistance development. Here, we studied persistence in a clinically relevant pathogen, Pseudomonas aeruginosa. It is one of the six ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, P. aeruginosa, and Enterobacter spp.), which are considered major health threats. P. aeruginosa is mostly known to cause chronic lung infections in cystic fibrosis patients. We mimicked these lung infections in a mouse model to study persistence under more clinical conditions. It was shown that the survival levels of natural P. aeruginosa isolates in this model are positively correlated with the survival levels measured in classical persistence assays in vitro. These results not only validate the use of our current techniques to study persistence but also open opportunities to study new persistence mechanisms or evaluate new antipersister strategies in vivo.

PMID:37140371 | DOI:10.1128/spectrum.04970-22