Learning to breathe with Tai Chi online - qualitative data from a randomized controlled feasibility study of patients with cystic fibrosis.

Eur J Integr Med. 2020 Oct 22;:101229

Authors: Ronan P, Mian A, Carr SB, Madge SL, Lorenc A, Robinson PN

Abstract
INTRODUCTION: Tai Chi (TC), a gentle exercise, incorporates meditative movement and respiratory control. The high risk of cross infection for people with cystic fibrosis (CF) requires close management in healthcare settings, limiting group activities such as TC. A mixed-methods randomized controlled feasibility study compared teaching TC over the internet with in-person, face to face TC tuition provided to CF patients. This article explores qualitative data from patients and TC instructors on their attitudes, acceptability and engagement with the two modes of TC delivery.
METHODS: Qualitative data from CF patients (>6 years) were collected using Skype interviews/focus groups and written feedback. TC instructors provided weekly written feedback, and took part in interviews/ focus groups at the end of the study. Patients and instructors interviews explored their experiences and engagement with TC online delivery and ability to practice.
RESULTS: Irrespective of the type of TC delivery, all CF participants interviewed (n=28) practiced between lessons and most wanted to continue TC. Teenagers were more likely to miss TC appointments. Internet delivery was well received by both patients and TC instructors. Two patients reported difficulties with screen size/camera and one with internet connectivity.
CONCLUSION: Both face-to-face and internet delivery of Tai Chi lessons were equally well received and perceived as beneficial. In the current COVID-19 pandemic, CF patients self-isolating may find this intervention provides important support, therefore the programme was made available on YouTube in April 2020 and linked to the websites of the CF charities funding the research.

PMID: 33106755 [PubMed - as supplied by publisher]

How precision medicine paved the way to the first cystic fibrosis drug.

Nature. 2020 Oct;586(7831):667-668

Authors: Ledford H

PMID: 33106644 [PubMed - in process]

Mutant CFTR Drives TWIST1 mediated epithelial-mesenchymal transition.

Cell Death Dis. 2020 Oct 26;11(10):920

Authors: Quaresma MC, Pankonien I, Clarke LA, Sousa LS, Silva IAL, Railean V, Doušová T, Fuxe J, Amaral MD

Abstract
Cystic fibrosis (CF) is a monogenetic disease resulting from mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene encoding an anion channel. Recent evidence indicates that CFTR plays a role in other cellular processes, namely in development, cellular differentiation and wound healing. Accordingly, CFTR has been proposed to function as a tumour suppressor in a wide range of cancers. Along these lines, CF was recently suggested to be associated with epithelial-mesenchymal transition (EMT), a latent developmental process, which can be re-activated in fibrosis and cancer. However, it is unknown whether EMT is indeed active in CF and if EMT is triggered by dysfunctional CFTR itself or a consequence of secondary complications of CF. In this study, we investigated the occurrence of EMT in airways native tissue, primary cells and cell lines expressing mutant CFTR through the expression of epithelial and mesenchymal markers as well as EMT-associated transcription factors. Transepithelial electrical resistance, proliferation and regeneration rates, and cell resistance to TGF-β1induced EMT were also measured. CF tissues/cells expressing mutant CFTR displayed several signs of active EMT, namely: destructured epithelial proteins, defective cell junctions, increased levels of mesenchymal markers and EMT-associated transcription factors, hyper-proliferation and impaired wound healing. Importantly, we found evidence that the mutant CFTR triggered EMT was mediated by EMT-associated transcription factor TWIST1. Further, our data show that CF cells are over-sensitive to EMT but the CF EMT phenotype can be reversed by CFTR modulator drugs. Altogether, these results identify for the first time that EMT is intrinsically triggered by the absence of functional CFTR through a TWIST1 dependent mechanism and indicate that CFTR plays a direct role in EMT protection. This mechanistic link is a plausible explanation for the high incidence of fibrosis and cancer in CF, as well as for the role of CFTR as tumour suppressor protein.

PMID: 33106471 [PubMed - in process]

Response of Pseudomonas aeruginosa to the innate immune system-derived oxidants hypochlorous acid and hypothiocyanous acid.

J Bacteriol. 2020 Oct 26;:

Authors: Farrant KV, Spiga L, Davies JC, Williams HD

Abstract
Pseudomonas aeruginosa is a significant nosocomial pathogen and associated with lung infections in cystic fibrosis (CF). Once established, P. aeruginosa infections persist and are rarely eradicated despite host immune cells producing antimicrobial oxidants, including hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN). There is limited knowledge as to how P. aeruginosa senses, responds to, and protects itself against HOCl and HOSCN, and the contribution of such responses to its success as a CF pathogen. To investigate the P. aeruginosa response to these oxidants we screened 707 transposon mutants, with mutations in regulatory genes, for altered growth following HOCl exposure. We identified regulators of antibiotic resistance, methionine biosynthesis and catabolite repression, and PA14_07340, the homologue of the Escherichia coli HOCl-sensor RclR (30% identical), that are required for protection against HOCl. We have shown that RclR (PA14_07340) protects specifically against HOCl and HOSCN stress, and responds to both oxidants by upregulating expression of a putative peroxiredoxin, rclX (PA14_07355). Transcriptional analysis revealed that while there was specificity in the response to HOCl (231 genes upregulated) and HOSCN (105 genes upregulated) there was considerable overlap, with 74 genes upregulated by both oxidants. These included genes encoding the type III secretion system, sulphur and taurine transport, and the MexEF-OprN efflux pump. RclR coordinates part of the response to both oxidants, including upregulation of pyocyanin biosynthesis genes, and in the presence of HOSCN, downregulation of chaperone genes. These data indicate that the P. aeruginosa response to HOCl and HOSCN is multifaceted, with RclR playing an essential role.IMPORTANCE The bacterial pathogen Pseudomonas aeruginosa causes devastating infections in immunocompromised hosts, including chronic lung infections in cystic fibrosis patients. To combat infection the host's immune system produces the antimicrobial oxidants hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN). Little is known about how P. aeruginosa responds to and survives attack from these oxidants. To address this, we carried out two approaches: a mutant screen and transcriptional study. We identified the P. aeruginosa transcriptional regulator, RclR, which responds specifically to HOCl and HOSCN stress, and is essential for protection against both oxidants. We uncovered a link between the P. aeruginosa transcriptional response to these oxidants and physiological processes associated with pathogenicity, including antibiotic resistance and the type III secretion system.

PMID: 33106346 [PubMed - as supplied by publisher]

The influence of carbohydrate ingestion on peripheral and central fatigue during exercise in hypoxia: a narrative review.

Eur J Sport Sci. 2020 Oct 27;:1-33

Authors: Paris HL, Sinai EC, Shei RJ, Keller AM, Mickleborough TD

Abstract
Hypoxia impairs aerobic performance by accelerating fatiguing processes. These processes may originate from sites either distal (peripheral) or proximal (central) to the neuromuscular junction, though these are not mutually exclusive. Peripheral mechanisms include decrements in muscle glycogen or fluctuations in intramuscular metabolites, whereas central responses commonly refer to reductions in central motor drive elicited by alterations in blood glucose and neurotransmitter concentrations as well as arterial hypoxemia. Hypoxia may accelerate both peripheral and central pathways of fatigue, with the level of hypoxia strongly dictating the degree and primary locus of impairment. As more people journey to hypoxic settings for work and recreation, developing strategies to improve work capacity in these environments becomes increasingly relevant. Given that sea level performance improves with nutritional interventions such as carbohydrate (CHO) ingestion, a similar strategy may prove effective in delaying fatigue in hypoxia, particularly considering how the metabolic pathways enhanced with CHO supplementation overlap the fatiguing pathways upregulated in hypoxia. Many questions regarding the relationship between CHO, hypoxia, and fatigue remain unanswered, including specifics on when to ingest, what to ingest, and how varying altitudes influence supplementation effectiveness. Therefore, the purpose of this narrative review is to examine the peripheral and central mechanisms contributing to fatigue during aerobic exercise at varying degrees of hypoxia and to assess the role of CHO ingestion in attenuating fatigue onset.

PMID: 33106121 [PubMed - as supplied by publisher]

Exploring the Utility of Noninvasive Type 2 Inflammatory Markers for Prediction of Severe Asthma Exacerbations in Children and Adolescents.

J Allergy Clin Immunol Pract. 2019 Nov - Dec;7(8):2624-2633.e2

Authors: Shah SP, Grunwell J, Shih J, Stephenson S, Fitzpatrick AM

Abstract
BACKGROUND: Noninvasive markers of type 2 inflammation are needed to identify children and adolescents who might benefit from personalized biologic therapy.
OBJECTIVE: We hypothesized that blood eosinophil counts would predict 1 or more acute visits for asthma and that prediction could be improved with the addition of a second, noninvasive type 2 inflammatory biomarker.
METHODS: Children and adolescents 5 to 21 years (N = 589) with an asthma exacerbation necessitating systemic corticosteroid treatment in the previous year completed a characterization visit and telephone calls at 6 and 12 months. The primary outcome was an acute visit for asthma with receipt of systemic corticosteroids. Acute visits were verified by medical record review. Exploratory outcomes included time to first acute visit and hospitalization.
RESULTS: Acute visits occurred in 106 (35.5%) children and 72 (24.8%) adolescents. Elevated blood eosinophils were associated with increased odds and shorter time to first acute visit, but optimal cut-points differed by age (≥150 vs ≥300 cells/μL for children vs adolescents, respectively). The addition of a second marker of type 2 inflammation did not improve prediction in children, but increased the odds and hazard of an acute visit up to 16.2% and 11.9%, respectively, in adolescents. Similar trends were noted for hospitalizations.
CONCLUSIONS: Blood eosinophils and other noninvasive markers of type 2 inflammation may be useful in the clinical assessment of children and adolescents with asthma. However, features of type 2 inflammation vary by age. Whether children and adolescents also respond differently to management of type 2 inflammation is unclear and warrants further evaluation.

PMID: 31100552 [PubMed - indexed for MEDLINE]

Exercise Intolerance in Cystic Fibrosis: Importance of Skeletal Muscle.

Med Sci Sports Exerc. 2020 Oct 22;:

Authors: Rodriguez-Miguelez P, Seigler N, Ishii H, Crandall R, McKie KT, Forseen C, Harris RA

Abstract
PURPOSE: Exercise intolerance, evaluated by O2 consumption, predicts mortality in Cystic Fibrosis (CF). People with CF exhibit skeletal muscle dysfunctions that may contribute to an imbalance between O2 delivery and utilization. Sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, increases blood flow and improves O2 consumption, although the exact mechanisms in CF have yet to be elucidated. Thus, we hypothesized that exercise intolerance in CF is limited primarily by an impaired skeletal muscle O2 utilization, and sildenafil improves exercise tolerance in CF by addressing this mismatch between O2 demand and extraction.
METHODS: Fifteen individuals with mild-to-moderate CF and eighteen healthy controls completed an incremental exercise test and measurements of gaseous exchange, chronotropic response, hemodynamics, and O2 extraction and utilization. People with CF also completed a four-week-treatment with sildenafil with a subsequent follow-up evaluation after treatment.
RESULTS: Skeletal muscle O2 extraction and utilization during exercise were reduced in people with CF when compared to controls. Exercise capacity in our CF population was minimally limited by hemodynamic or chronotopic responses, while peripheral O2 extraction was more closely associated with exercise capacity. The study also demonstrated that four weeks of sildenafil improved skeletal muscle O2 utilization during exercise to similar values observed in healthy individuals.
CONCLUSIONS: Individuals with mild to moderate CF exhibit exercise intolerance secondary to a reduction in O2 utilization by the exercising skeletal muscle. The present study demonstrated that four weeks of sildenafil treatment improves the capacity of the skeletal muscle to utilize O2 more efficiently during exercise. Findings from the present study highlight the importance of targeting skeletal muscle O2 utilization to improve exercise tolerance in CF.

PMID: 33105385 [PubMed - as supplied by publisher]

Implementing a tracking system for confirmatory diagnostic results after positive newborn screening for cystic fibrosis-implications for process quality and patient care.

Eur J Pediatr. 2020 Oct 26;:

Authors: Gramer G, Brockow I, Labitzke C, Fang-Hoffmann J, Beivers A, Feyh P, Hoffmann GF, Nennstiel U, Sommerburg O

Abstract
Newborn screening for cystic fibrosis (CF-NBS) was introduced in Germany in 2016. Currently, systematic follow-up of positive CF-NBS results is not implemented or reimbursed in the NBS program. We investigated results of confirmatory testing over 24 months after implementation of CF-NBS for a large German NBS center before and after introduction of an active tracking system and performed a cost calculation for tracking. Results are compared with the federal state of Bavaria, where a centralized tracking system has been in place for many years. At the NBS center, 244 of 281,907 children had a positive CF-NBS result requiring diagnostic confirmation. Before implementation of a telephone tracking system, only 43% of confirmatory results were returned despite repeated written requests. The consecutive strategy including telephone tracking led to an increase of resolved cases to 84%. However, the centralized tracking system in Bavaria, assigning children with positive CF-NBS directly to a responsible CF-center, resolved 99% of cases. The calculated additional cost for a tracking system in Germany including telephone tracking is 1.20€ per newborn screened.Conclusion: The implementation of a tracking system achieves a distinct improvement in CF-NBS with justifiable costs. The effect can be limited by absence of centralized organization of confirmatory testing. What is Known: • Newborn screening for cystic fibrosis (CF-NBS) has been performed for many years in several countries worldwide • While many studies have focused on different CF-NBS strategies, the organization of confirmatory testing and process quality concerning returned information to the NBS center has so far received less attention. What is New: • The implementation of an active tracking system achieves a distinct improvement of clarified cases after positive CF-NBS with justifiable costs. • The effect of a tracking system can be limited by the absence of a centralized organization of confirmatory testing.

PMID: 33104872 [PubMed - as supplied by publisher]

Biological basis of child health 5: development of the respiratory system and elements of respiratory assessment.

Nurs Child Young People. 2020 Aug 17;:

Authors: Crawford D, Davies K

Abstract
This article is the fifth in a series on the biological basis of child health. It describes the development of the respiratory system, which starts relatively late in the embryo and continues after birth until the age of seven to eight years. It explains what the developing anatomy of the respiratory system in infants and children means in terms of the conditions that may occur and the precautions required when assessing them. The article provides an overview of the elements of respiratory assessment in infants and children and describes some respiratory conditions seen in these patient groups. It also discusses some of the changes in the care of children with respiratory conditions, which has increasingly moved from hospital into the community and become nurse-led, multidisciplinary and holistic.

PMID: 33104299 [PubMed - as supplied by publisher]

Bibliometric analysis of chloride channel research (2004-2019).

Channels (Austin). 2020 Dec;14(1):393-402

Authors: Shi J, Shi S, Yuan G, Jia Q, Shi S, Zhu X, Zhou Y, Chen T, Hu Y

PMID: 33103563 [PubMed - in process]

Upper Airway Findings and Markers of Lung Disease Progression in Patients with Cystic Fibrosis.

Int Arch Otorhinolaryngol. 2020 Oct;24(4):e434-e437

Authors: Steffen LM, Pezzin LS, Sulis N, Steffen N, Pinto LA

Abstract
Introduction  Cystic fibrosis (CF) is a genetic disease that limits the quality of life mainly due to respiratory symptoms. The relationship between findings of the upper airways and CF lung disease is not yet completely understood. Objective  The aim of the present study is to describe the most frequent nasal findings and pathogens in patients with CF and investigate the association between the findings of the upper respiratory tract and markers of lung disease progression. Methods  Retrospective study in patients with CF from the Pediatric Pulmonology Department who underwent otorhinolaryngological evaluation between 2015 and 2017. Nasal endoscopy and nasal swab collection were part of the evaluation. The severity markers used were: percentage of predicted forced expiratory volume in the first second (FEV1%), body mass index (BMI) and the Shwachman-Kulczycki (SK) clinical score. Results  A total of 48 patients with CF were included. The mean of the predicted percentage of FEV1% was 83.36 ± 30.04. The average 14 and SK score 89.11 ± 10.50. The bacteriology of the nasal swab was positive in 27 (54.1%) patients. Staphylococcus aureus was positive in 18 patients, Pseudomonas aeruginosa in 5, Pseudomonas cepacea in 3 and Stenotrophomonas maltophila in 1 patient. Nasal polyps were found in nine participants. Nasal polyps were found in nine participants and were associated with lower SK score. Conclusion  The pathogens found in the upper airway were, in order: S. aureus , P. aeruginosa , P. cepacea e S. maltophila . The presence of polyps in the nasal cavity showed statistical significance and appears to have association with the prognostic factor measured by the SK score.

PMID: 33101507 [PubMed]

Comparative Evolutionary Patterns of Burkholderia cenocepacia and B. multivorans During Chronic Co-infection of a Cystic Fibrosis Patient Lung.

Front Microbiol. 2020;11:574626

Authors: Hassan AA, Dos Santos SC, Cooper VS, Sá-Correia I

Abstract
During chronic respiratory infections of cystic fibrosis (CF) patients, bacteria adaptively evolve in response to the nutritional and immune environment as well as influence other infecting microbes. The present study was designed to gain insights into the genetic mechanisms underlying adaptation and diversification by the two most prevalent pathogenic species of the Burkholderia cepacia complex (Bcc), B. cenocepacia and B. multivorans. Herein, we study the evolution of both of these species during coinfection of a CF patient for 4.4 years using genome sequences of 9 B. multivorans and 11 B. cenocepacia. This co-infection spanned at least 3 years following initial infection by B. multivorans and ultimately ended in the patient's death by cepacia syndrome. Both species acquired several mutations with accumulation rates of 2.08 (B. cenocepacia) and 2.27 (B. multivorans) SNPs/year. Many of the mutated genes are associated with oxidative stress response, transition metal metabolism, defense mechanisms against antibiotics, and other metabolic alterations consistent with the idea that positive selection might be driven by the action of the host immune system, antibiotic therapy and low oxygen and iron concentrations. Two orthologous genes shared by B. cenocepacia and B. multivorans were found to be under strong selection and accumulated mutations associated with lineage diversification. One gene encodes a nucleotide sugar dehydratase involved in lipopolysaccharide O-antigen (OAg) biosynthesis (wbiI). The other gene encodes a putative two-component regulatory sensor kinase protein required to sense and adapt to oxidative- and heavy metal- inducing stresses. This study contributes to understanding of shared and species-specific evolutionary patterns of B. cenocepacia and B. multivorans evolving in the same CF lung environment.

PMID: 33101250 [PubMed]

Temperate Bacteriophages (Prophages) in Pseudomonas aeruginosa Isolates Belonging to the International Cystic Fibrosis Clone (CC274).

Front Microbiol. 2020;11:556706

Authors: Ambroa A, Blasco L, López-Causapé C, Trastoy R, Fernandez-García L, Bleriot I, Ponce-Alonso M, Pacios O, López M, Cantón R, Kidd TJ, Bou G, Oliver A, Tomás M

Abstract
Bacteriophages are important in bacterial ecology and evolution. Pseudomonas aeruginosa is the most prevalent bacterial pathogen in chronic bronchopulmonary infection in cystic fibrosis (CF). In this study, we used bioinformatics, microbiological and microscopy techniques to analyze the bacteriophages present in 24 P. aeruginosa isolates belonging to the international CF clone (ST274-CC274). Interestingly, we detected the presence of five members of the Inoviridae family of prophages (Pf1, Pf4, Pf5, Pf6, Pf7), which have previously been observed in P. aeruginosa. In addition, we identified a new filamentous prophage, designated Pf8, in the P. aeruginosa AUS411.500 isolate belonging to the international CF clone. We detected only one prophage, never previously described, from the family Siphoviridiae (with 66 proteins and displaying homology with PHAGE_Pseudo_phi297_NC_016762). This prophage was isolated from the P. aeruginosa AUS531 isolate carrying a new gene which is implicated in the phage infection ability, named Bacteriophage Control Infection (bci). We characterized the role of the Bci protein in bacteriophage infection and in regulating the host Quorum Sensing (QS) system, motility and biofilm and pyocyanin production in the P. aeruginosa isogenic mutant AUS531Δbci isolate. The findings may be relevant for the identification of targets in the development of new strategies to control P. aeruginosa infections, particularly in CF patients.

PMID: 33101229 [PubMed]

Mitochondrial Stress Responses and "Mito-Inflammation" in Cystic Fibrosis.

Front Pharmacol. 2020;11:581114

Authors: Patergnani S, Vitto VAM, Pinton P, Rimessi A

Abstract
Cystic fibrosis (CF) is a genetic disease associated to mutations in the cystic fibrosis transmembrane conductance regulator gene, which results in the alteration of biological fluid and electrolyte homeostasis. The characteristic pathological manifestation is represented by exaggerated proinflammatory response in lung of CF patients, driven by recurrent infections and worsen by hypersecretion of proinflammatory mediators and progressive tissue destruction. Treating inflammation remains a priority in CF. However, current anti-inflammatory treatments, including non-steroidal agents, are poorly effective and present dramatic side effects in CF patients. Different studies suggest an intimate relationship between mitochondria and CF lung disease, supporting the hypothesis that a decline in mitochondrial function endorses the development of the hyperinflammatory phenotype observed in CF lung. This allowed the implementation of a new concept: the "mito-inflammation," a compartmentalization of inflammatory process, related to the role of mitochondria in engage and sustain the inflammatory responses, resulting a druggable target to counteract the amplification of inflammatory signals in CF. Here, we will offer an overview of the contribution of mitochondria in the pathogenesis of CF lung disease, delving into mitochondrial quality control responses, which concur significantly to exacerbation of CF lung inflammatory responses. Finally, we will discuss the new therapeutic avenues that aim to target the mito-inflammation, an alternative therapeutic advantage for mitochondrial quality control that improves CF patient's inflammatory state.

PMID: 33101035 [PubMed]

Airway Mucins Inhibit Oxidative and Non-Oxidative Bacterial Killing by Human Neutrophils.

Front Pharmacol. 2020;11:554353

Authors: Cantin AM, Ouellet C, Cloutier A, McDonald PP

Abstract
Neutrophil killing of bacteria is mediated by oxidative and non-oxidative mechanisms. Oxidants are generated through the NADPH oxidase complex, whereas antimicrobial proteins and peptides rank amongst non-oxidative host defenses. Mucus hypersecretion, deficient hydration and poor clearance from the airways are prominent features of cystic fibrosis (CF) lung disease. CF airways are commonly infected by Pseudomonas aeruginosa and Burkholderia cepacia complex bacteria. Whereas the former bacterium is highly sensitive to non-oxidative killing, the latter is only killed if the oxidative burst is intact. Despite an abundance of neutrophils, both pathogens thrive in CF airway secretions. In this study, we report that secreted mucins protect these CF pathogens against host defenses. Mucins were purified from CF sputum and from the saliva of healthy volunteers. Whereas mucins did not alter the phagocytosis of Pseudomonas aeruginosa and Burkholderia cenocepacia by neutrophils, they completely suppressed bacterial killing. Accordingly, mucins markedly inhibited non-oxidative bacterial killing by neutrophil granule extracts, or by lysozyme and the cationic peptide, human β defensin-2 (HBD2). Mucins also suppressed the neutrophil oxidative burst through a charge-dependent mechanism that could be reversed by the cationic aminoglycoside, tobramycin. Our data indicate that airway mucins protect Gram-negative bacteria against neutrophil killing by suppressing the oxidative burst and inhibiting the bactericidal capacity of cationic proteins and peptides. Mucin hypersecretion, dehydration, stasis and anionic charge represent key therapeutic targets for improving host defenses and airway inflammation in CF and other muco-secretory airway diseases.

PMID: 33101020 [PubMed]

Clinical features associated with a doctor-diagnosis of bronchiectasis in the Severe Asthma Network in Italy (SANI) registry.

Expert Rev Respir Med. 2020 Oct 24;:

Authors: Malipiero G, Paoletti G, Blasi F, Paggiaro P, Senna G, Latorre M, Caminati M, Carpagnano GE, Crimi N, Spanevello A, Aliberti S, Canonica GW, Heffler E

Abstract
BACKGROUND: Several severe asthma comorbidities and have been identified. One of the emerging comorbidities is bronchiectasis. We evaluated the frequency of bronchiectasis on severe asthma in a real life setting, by analyzing the data collected by the "Severe Asthma Network Italy" (SANI) registry.
METHODS: SANI registry encompasses demographic, clinical, functional and inflammatory data of Italian severe asthmatics. Data obtained by the enrolled patients were analyzed, focusing the attention to those patients with concomitant clinically relevant bronchiectasis.
RESULTS: 15.5% patients have a clinical-radiological diagnosis of bronchiectasis. Bronchiectasis diagnosis was associated with a higher prevalence of chronic rhinosinusitis with nasal polyps (54.6% vs. 38%, p=0.001) and higher serum IgE levels (673.4 vs. 412.1 kUI/L, p=0.013). Patients with bronchiectasis had worse asthma control (ACT: 16.7 vs 18.2, p=0.013), worse quality of life (AQLQ: 4.08 vs. 4.60, p=0.02) and lower lung function (FEV1% predicted 67.3 vs. 75.0, p=0.002). A higher rate of severe asthma exacerbations in the previous 12 months (85.2% vs. 61.5%, p<0.001) was found in patients with bronchiectasis.
CONCLUSION: severe asthma associated with bronchiectasis represents a particularly severe asthma variant, possibly driven by an eosinophilic endotype. We therefore suggest that bronchiectasis should necessarily be assessed in severe asthmatic patients.

PMID: 33100041 [PubMed - as supplied by publisher]

Derivation of Airway Basal Stem Cells from Human Pluripotent Stem Cells.

Cell Stem Cell. 2020 Oct 19;:

Authors: Hawkins FJ, Suzuki S, Beermann ML, Barillà C, Wang R, Villacorta-Martin C, Berical A, Jean JC, Le Suer J, Matte T, Simone-Roach C, Tang Y, Schlaeger TM, Crane AM, Matthias N, Huang SXL, Randell SH, Wu J, Spence JR, Carraro G, Stripp BR, Rab A, Sorsher EJ, Horani A, Brody SL, Davis BR, Kotton DN

Abstract
The derivation of tissue-specific stem cells from human induced pluripotent stem cells (iPSCs) would have broad reaching implications for regenerative medicine. Here, we report the directed differentiation of human iPSCs into airway basal cells ("iBCs"), a population resembling the stem cell of the airway epithelium. Using a dual fluorescent reporter system (NKX2-1GFP;TP63tdTomato), we track and purify these cells as they first emerge as developmentally immature NKX2-1GFP+ lung progenitors and subsequently augment a TP63 program during proximal airway epithelial patterning. In response to primary basal cell medium, NKX2-1GFP+/TP63tdTomato+ cells display the molecular and functional phenotype of airway basal cells, including the capacity to self-renew or undergo multi-lineage differentiation in vitro and in tracheal xenografts in vivo. iBCs and their differentiated progeny model perturbations that characterize acquired and genetic airway diseases, including the mucus metaplasia of asthma, chloride channel dysfunction of cystic fibrosis, and ciliary defects of primary ciliary dyskinesia.

PMID: 33098807 [PubMed - as supplied by publisher]

The odorant receptor OR2W3 on airway smooth muscle evokes bronchodilation via a cooperative chemosensory tradeoff between TMEM16A and CFTR.

Proc Natl Acad Sci U S A. 2020 Oct 23;:

Authors: Huang J, Lam H, Koziol-White C, Limjunyawong N, Kim D, Kim N, Karmacharya N, Rajkumar P, Firer D, Dalesio NM, Jude J, Kurten RC, Pluznick JL, Deshpande DA, Penn RB, Liggett SB, Panettieri RA, Dong X, An SS

Abstract
The recent discovery of sensory (tastant and odorant) G protein-coupled receptors on the smooth muscle of human bronchi suggests unappreciated therapeutic targets in the management of obstructive lung diseases. Here we have characterized the effects of a wide range of volatile odorants on the contractile state of airway smooth muscle (ASM) and uncovered a complex mechanism of odorant-evoked signaling properties that regulate excitation-contraction (E-C) coupling in human ASM cells. Initial studies established multiple odorous molecules capable of increasing intracellular calcium ([Ca2+]i) in ASM cells, some of which were (paradoxically) associated with ASM relaxation. Subsequent studies showed a terpenoid molecule (nerol)-stimulated OR2W3 caused increases in [Ca2+]i and relaxation of ASM cells. Of note, OR2W3-evoked [Ca2+]i mobilization and ASM relaxation required Ca2+ flux through the store-operated calcium entry (SOCE) pathway and accompanied plasma membrane depolarization. This chemosensory odorant receptor response was not mediated by adenylyl cyclase (AC)/cyclic nucleotide-gated (CNG) channels or by protein kinase A (PKA) activity. Instead, ASM olfactory responses to the monoterpene nerol were predominated by the activity of Ca2+-activated chloride channels (TMEM16A), including the cystic fibrosis transmembrane conductance regulator (CFTR) expressed on endo(sarco)plasmic reticulum. These findings demonstrate compartmentalization of Ca2+ signals dictates the odorant receptor OR2W3-induced ASM relaxation and identify a previously unrecognized E-C coupling mechanism that could be exploited in the development of therapeutics to treat obstructive lung diseases.

PMID: 33097666 [PubMed - as supplied by publisher]

Phenotypic and transcriptomic analysis of seven clinical Stenotrophomonas maltophilia isolates identify a small set of shared and commonly regulated genes involved in biofilm lifestyle.

Appl Environ Microbiol. 2020 Oct 23;:

Authors: Alio I, Gudzuhn M, Pérez García P, Danso D, Schoelmerich M, Mamat U, Schaible UE, Steinmann J, Yero D, Gibert I, Kohl TA, Niemann S, Gröschel MI, Haerdter J, Hackl T, Vollstedt C, Bömeke M, Egelkamp R, Daniel R, Poehlein A, Streit WR

Abstract
Stenotrophomonas maltophilia is one of the most frequently isolated multidrug resistant nosocomial opportunistic pathogens. It contributes to disease progression in cystic fibrosis patients and is frequently isolated from wounds, infected tissues or catheter surfaces. On these diverse surfaces S. maltophilia lives in single or multi-species biofilms. Since very little is known about common processes in biofilms of different S. maltophilia isolates, we analyzed the biofilm profiles of 300 clinical and environmental isolates from Europe of the recently identified main lineages Sgn3, Sgn4 and Sm2 - Sm18. The analysis of the biofilm architecture of 40 clinical isolates revealed the presence of multicellular structures and high phenotypic variability at a strain-specific level. Further, transcriptome analyses of biofilm cells of seven clinical isolates identified a set of 106 shared strongly expressed genes and 33 strain-specifically expressed genes. Surprisingly, the transcriptome profiles of biofilm versus planktonic cells revealed that just 9.43 ± 1.36 % of all genes were differentially regulated. This implies that just a small set of shared and commonly regulated genes is involved in the biofilm lifestyle. Strikingly, iron uptake appears to be a key factor involved in this metabolic shift. Further, metabolic analyses implied that S. maltophilia employs a mostly fermentative growth mode under biofilm conditions. The transcriptome data of this study together with the phenotypic and metabolic analysis represent so far the largest data set on S. maltophilia biofilm versus planktonic cells. This study will lay the foundation for the identification of strategies for fighting S. maltophilia biofilms in clinical and industrial settings.IMPORTANCEMicroorganisms living in a biofilm are much more tolerant to antibiotics and antimicrobial substances than planktonic cells. Thus, the treatment of infections caused by microorganisms living in biofilms is extremely difficult. The nosocomial infections among others caused by S. maltophilia, particularly lung infection among CF patients, increased in prevalence in the last years. The intrinsic multidrug resistance of S. maltophilia and the increased tolerance to antimicrobial agents of its biofilm cells, makes the treatment of S. maltophilia infection difficult. The significance of our research is based in understanding the common mechanisms involved in biofilm formation of different S. maltophilia isolates, understanding the diversity of biofilm architectures among this species and in identifying the differently regulated processes in biofilm versus planktonic cells. These results will lay the foundation for the treatment of S. maltophilia biofilms.

PMID: 33097507 [PubMed - as supplied by publisher]

High-level antibiotic tolerance of a clinically-isolated Enterococcus faecalis strain.

Appl Environ Microbiol. 2020 Oct 23;:

Authors: Gu H, Roy S, Zheng X, Gao T, Ma H, Soultan Z, Fortner C, Nangia S, Ren D

Abstract
Bacteria can survive antibiotic treatment both by acquiring antibiotic resistance genes, and through mechanisms of tolerance that are based on phenotypic changes and the formation of metabolically inactive cells. Here, we report an Enterococcus faecalis strain (E. faecalis UM001B) isolated from a cystic fibrosis patient that has no increase in resistance but extremely high-level tolerance to ampicillin, vancomycin, and tetracycline. Specifically, the percentage of cells that survive 3.5-h antibiotic treatment (at 100 μg ⋅mL-1) is 25.4 ± 4.3% and 51.9 ± 4.0% for ampicillin and tetracycline, respectively; and vancomycin does not exhibit any significant killing. Consistent with the change in antibiotic susceptibility, UM001B is found to have reduced penetration of ampicillin and vancomycin, and accumulation of tetracycline compared to the reference strain ATCC29212. Based on whole-genome sequencing (WGS), four amino acid variants are identified in one of the tetracycline efflux pump repressors (TetRs) compared to ATCC29212. Results of molecular simulations and experimental assays reveal that these mutations can lead to a higher level of tetracycline efflux activity. Consistently, replicating these mutations in Escherichia coli MG1655 increases its tolerance to tetracycline. Overall, these findings provide new insights into the development of multidrug tolerance in E. faecalis, which can help future studies to better control enterococcal infections.IMPORTANCE. Enterococcus faecalis represents a major group of pathogens causing nosocomial infections that are resistant to multiple classes of antibiotics. An important challenge associated with E. faecalis infection is the emergence of multidrug tolerant strains, which have normal minimum inhibitory concentrations (MICs) but do not respond to antibiotic treatment. Here, we report a strain of E. faecalis isolated from a cystic fibrosis patient that demonstrates high-level tolerance to ampicillin, vancomycin, and tetracycline. Whole-genome sequencing reveals critical variants in one of the tetracycline efflux pump repressors, consistent with the increased tolerance of E. faecalis UM001B to tetracycline. These findings provide new information about bacterial antibiotic tolerance and may help develop more effective therapeutics.

PMID: 33097497 [PubMed - as supplied by publisher]