[Management of adult bronchiectasis].

Rev Med Liege. 2016 Oct;71(10):440-448

Authors: Tassart G, Pieters T, Gohy S

Abstract
Non-cystic fibrosis bronchiectasis has been the subject of renewed interest over recent years. It is usually part of the evolutionary process of many infectious, autoimmune, genetic, developmental or allergic diseases. Its presentation and prognosis are heterogeneous and it causes significant morbidity and mortality with a real impact on the health care system. Thanks to increasingly available guidelines, it is now possible to define the optimal management that will include various therapeutic objectives : airway clearance, prevention and eradication of bacterial colonization, reduction of airway inflammation and exacerbations and improvement of quality of life.

PMID: 28383852 [PubMed - in process]

A pan-genomic approach to understand the basis of host adaptation in Achromobacter.

Genome Biol Evol. 2017 Apr 05;:

Authors: Jeukens J, Freschi L, Vincent AT, Emond-Rheault JG, Kukavica-Ibrulj I, Charette SJ, Levesque RC

Abstract
Over the past decade, there has been a rising interest in Achromobacter sp., an emerging opportunistic pathogen responsible for nosocomial and cystic fibrosis (CF) lung infections. Species of this genus are ubiquitous in the environment, can outcompete resident microbiota, and are resistant to commonly used disinfectants as well as antibiotics. Nevertheless, the Achromobacter genus suffers from difficulties in diagnosis, unresolved taxonomy and limited understanding of how it adapts to the CF lung, not to mention other host environments. The goals of this first genus-wide comparative genomics study were to clarify the taxonomy of this genus and identify genomic features associated with pathogenicity and host adaptation. This was done with a widely applicable approach based on pan-genome analysis. First, using all publicly available genomes, a combination of phylogenetic analysis based on 1,780 conserved genes with average nucleotide identity and accessory genome composition allowed the identification of a largely clinical lineage composed of A. xylosoxidans A insuavis A. dolens and A. ruhlandii. Within this lineage, we identified 35 positively selected genes involved in metabolism, regulation and efflux-mediated antibiotic resistance. Second, resistome analysis showed that this clinical lineage carried additional antibiotic resistance genes compared to other isolates. Finally, we identified putative mobile elements that contribute 53% of the genus's resistome and support horizontal gene transfer between Achromobacter and other ecologically similar genera. This study provides strong phylogenetic and pan-genomic bases to motivate further research on Achromobacter, and contributes to the understanding of opportunistic pathogen evolution.

PMID: 28383665 [PubMed - as supplied by publisher]

Doxycycline improves clinical outcomes during cystic fibrosis exacerbations.

Eur Respir J. 2017 Apr;49(4):

Authors: Xu X, Abdalla T, Bratcher PE, Jackson PL, Sabbatini G, Wells JM, Lou XY, Quinn R, Blalock JE, Clancy JP, Gaggar A

Abstract
Matrix metalloprotease-9 (MMP-9) plays a role in progression of cystic fibrosis, and doxycycline can reduce MMP-9 in vitro Here, we explore the effect of doxycycline during cystic fibrosis exacerbation treatment on MMP-9 related readouts and clinical end-points.This randomised, double-blind, placebo-controlled study enrolled hospitalised patients with cystic fibrosis undergoing exacerbation. In total, 20 participants were given doxycycline and 19 participants were given placebo over an 8-day period during hospitalisation. Biospecimens were collected at the beginning and the end of the study period. Primary end-points were total MMP-9 levels in the sputum and safety/tolerability. Secondary end-points included change in lung function, time to next exacerbation, and markers of MMP-9-related protease activity (active MMP-9 and TIMP-1). Nonparametric testing was used for within-group and between-group analyses.Doxycycline was well tolerated, with no treatment discontinuations or serious adverse events. Doxycycline reduced total sputum MMP-9 levels by 63.2% (p<0.05), and was also associated with a 56.5% reduction in active MMP-9 levels (p<0.05), a 1.6-fold increase in sputum TIMP-1 (p<0.05), improvement in forced expiratory volume in 1 s (p<0.05), and an increase in time to next exacerbation (p<0.01).Adjunctive use of doxycycline improved dysregulated MMP-9 levels in sputum, along with biomarkers consistent with a reduced proteolytic pulmonary environment. Improvement in clinical outcome measures suggests an important therapeutic benefit of doxycycline for individuals with cystic fibrosis.

PMID: 28381428 [PubMed - in process]

Transplanted lungs and the "white plague": A case-report and review of the literature.

Medicine (Baltimore). 2017 Mar;96(13):e6173

Authors: Cassir N, Delacroix R, Gomez C, Secq V, Reynaud-Gaubert M, Thomas PA, Papazian L, Drancourt M

Abstract
RATIONALE: Solid organ transplant recipients, especially after lung transplantation, are at increased risk for Mycobacterium tuberculosis pulmonary tuberculosis due to lifelong immunosuppression.
PATIENT CONCERNS: A 41-year-old woman underwent a second bilateral lung transplantation that was complicated by fatal pulmonary tuberculosis.
DIAGNOSES: Histological examination of a lung biopsy performed 6 weeks after retransplantation revealed a caseating granuloma and necrosis. Acid-fast bacilli were identified as rifampicin-susceptible M. tuberculosis by real-time polymerase chain reaction (PCR), confirmed by culture 2 weeks later.
INTERVENTIONS: Our investigation led us to highly suspect that the transplanted lungs were the source of M. tuberculosis transmission.
LESSONS: In order to optimize diagnosis and treatment for lung recipients with latent or active tuberculosis, regular assessment of lower respiratory samples for M. tuberculosis, particularly during the 12-month period posttransplant should be implemented. Regarding donor-derived transmission, screening donor grafts with latent tuberculosis by M. tuberculosis real-time PCR in lymphoid and adipose tissues is an option that should be considered.

PMID: 28353558 [PubMed - indexed for MEDLINE]

Further Evidence for Bats as the Evolutionary Source of Middle East Respiratory Syndrome Coronavirus.

MBio. 2017 Apr 04;8(2):

Authors: Anthony SJ, Gilardi K, Menachery VD, Goldstein T, Ssebide B, Mbabazi R, Navarrete-Macias I, Liang E, Wells H, Hicks A, Petrosov A, Byarugaba DK, Debbink K, Dinnon KH, Scobey T, Randell SH, Yount BL, Cranfield M, Johnson CK, Baric RS, Lipkin WI, Mazet JA

Abstract
The evolutionary origins of Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) are unknown. Current evidence suggests that insectivorous bats are likely to be the original source, as several 2c CoVs have been described from various species in the family Vespertilionidae Here, we describe a MERS-like CoV identified from a Pipistrellus cf. hesperidus bat sampled in Uganda (strain PREDICT/PDF-2180), further supporting the hypothesis that bats are the evolutionary source of MERS-CoV. Phylogenetic analysis showed that PREDICT/PDF-2180 is closely related to MERS-CoV across much of its genome, consistent with a common ancestry; however, the spike protein was highly divergent (46% amino acid identity), suggesting that the two viruses may have different receptor binding properties. Indeed, several amino acid substitutions were identified in key binding residues that were predicted to block PREDICT/PDF-2180 from attaching to the MERS-CoV DPP4 receptor. To experimentally test this hypothesis, an infectious MERS-CoV clone expressing the PREDICT/PDF-2180 spike protein was generated. Recombinant viruses derived from the clone were replication competent but unable to spread and establish new infections in Vero cells or primary human airway epithelial cells. Our findings suggest that PREDICT/PDF-2180 is unlikely to pose a zoonotic threat. Recombination in the S1 subunit of the spike gene was identified as the primary mechanism driving variation in the spike phenotype and was likely one of the critical steps in the evolution and emergence of MERS-CoV in humans.IMPORTANCE Global surveillance efforts for undiscovered viruses are an important component of pandemic prevention initiatives. These surveys can be useful for finding novel viruses and for gaining insights into the ecological and evolutionary factors driving viral diversity; however, finding a viral sequence is not sufficient to determine whether it can infect people (i.e., poses a zoonotic threat). Here, we investigated the specific zoonotic risk of a MERS-like coronavirus (PREDICT/PDF-2180) identified in a bat from Uganda and showed that, despite being closely related to MERS-CoV, it is unlikely to pose a threat to humans. We suggest that this approach constitutes an appropriate strategy for beginning to determine the zoonotic potential of wildlife viruses. By showing that PREDICT/PDF-2180 does not infect cells that express the functional receptor for MERS-CoV, we further show that recombination was likely to be the critical step that allowed MERS to emerge in humans.

PMID: 28377531 [PubMed - in process]

Phage Inhibit Pathogen Dissemination by Targeting Bacterial Migrants in a Chronic Infection Model.

MBio. 2017 Apr 04;8(2):

Authors: Darch SE, Kragh KN, Abbott EA, Bjarnsholt T, Bull JJ, Whiteley M

Abstract
The microbial communities inhabiting chronic infections are often composed of spatially organized micrometer-sized, highly dense aggregates. It has recently been hypothesized that aggregates are responsible for the high tolerance of chronic infections to host immune functions and antimicrobial therapies. Little is currently known regarding the mechanisms controlling aggregate formation and antimicrobial tolerance primarily because of the lack of robust, biologically relevant experimental systems that promote natural aggregate formation. Here, we developed an in vitro model based on chronic Pseudomonas aeruginosa infection of the cystic fibrosis (CF) lung. This model utilizes a synthetic sputum medium that readily promotes the formation of P. aeruginosa aggregates with sizes similar to those observed in human CF lung tissue. Using high-resolution imaging, we exploited this model to elucidate the life history of P. aeruginosa and the mechanisms that this bacterium utilizes to tolerate antimicrobials, specifically, bacteriophage. In the early stages of growth in synthetic sputum, planktonic cells form aggregates that increase in size over time by expansion. In later growth, migrant cells disperse from aggregates and colonize new areas, seeding new aggregates. When added simultaneously with phage, P. aeruginosa was readily killed and aggregates were unable to form. When added after initial aggregate formation, phage were unable to eliminate all of the aggregates because of exopolysaccharide production; however, seeding of new aggregates by dispersed migrants was inhibited. We propose a model in which aggregates provide a mechanism that allows P. aeruginosa to tolerate phage therapy during chronic infection without the need for genetic mutation.IMPORTANCE Bacteria in chronic infections often reside in communities composed of micrometer-sized, highly dense aggregates. A primary challenge for studying aggregates has been the lack of laboratory systems that promote natural aggregate formation in relevant environments. Here, we developed a growth medium that mimics chronic lung infection and promotes natural aggregate formation by the bacterium Pseudomonas aeruginosa High-resolution, single-cell microscopy allowed us to characterize P. aeruginosa's life history-seeding, aggregate formation, and dispersal-in this medium. Our results reveal that this bacterium readily forms aggregates that release migrants to colonize new areas. We also show that aggregates allow P. aeruginosa to tolerate therapeutic bacteriophage addition, although this treatment limits P. aeruginosa dissemination by targeting migrants.

PMID: 28377527 [PubMed - in process]

Clarithromycin and N-Acetylcysteine co-spray-dried powders for pulmonary drug delivery: A focus on drug solubility.

Int J Pharm. 2017 Apr 01;:

Authors: Manniello MD, Del Gaudio P, Aquino RP, Russo P

Abstract
Cystic fibrosis (CF) lungs are usually susceptible to Pseudomonas aeruginosa colonization and this bacterium is resistant to immune system clearance and drug control. Particularly, the biofilm mode of growth protects several microorganisms from host defenses and antibacterial drugs, mainly due to a delayed penetration of the drug through the biofilm matrix. Biofilm, together with lung mucus viscosity and tenacity, reduces, therefore, the effectiveness of conventional antibiotic therapy in CF. The aim of this research was to design and develop a stable, portable, easy to use dry powder inhaler (DPI) for CF patients, able to release directly to the lung an association of macrolide antibiotics (clarithromycin) and a mucolytic agent (N-Acetyl-Cysteine). Its effectiveness is based on the counteracting of the characteristics of P. aeruginosa infections in CF (lung bacterial adhesion to lung epithelium, biofilm formation and mucus viscosity) and the ability to let the antimicrobial drug exert their pharmacological action. A solution of these two drugs, without any excipients, was spray-dried to obtain respirable microparticles, characterized by aerodynamic diameters suitable for inhalation (<5.0μm). The morphology evaluation evidenced a particles shape dependent on water content in the spray drying feeds, with wrinkle particles more evident with higher water content. Moreover, thanks to the presence of N-acetylcysteine which can interact with clarithromycin dimethyl-amino group, a consistent enhancement of drug solubility was obtained, compared to raw material and to the drug sprayed alone. The mucolytic agent added in the DPI may improve the macrolide diffusion into the mucus, enabling its action.

PMID: 28377314 [PubMed - as supplied by publisher]

High-Throughput Screening for Readthrough Modulators of CFTR PTC Mutations.

SLAS Technol. 2017 Feb 01;:2472630317692561

Authors: Liang F, Shang H, Jordan NJ, Wong E, Mercadante D, Saltz J, Mahiou J, Bihler HJ, Mense M

Abstract
Cystic fibrosis (CF) is a hereditary disease caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR). A large number of nearly 2000 reported mutations, including the premature termination codon (PTC) mutations, urgently require new and personalized medicines. We have developed cell-based assays for readthrough modulators of CFTR PTC mutations (or nonsense mutation suppressors), based on the trafficking and surface expression of CFTR. Approximately 85,000 compounds have been screened for two PTC mutations (Y122X and W1282X). The hit rates at the threshold of 50% greater than vehicle response are 2% and 1.4% for CFTR Y122X and CFTR W1282X, respectively. The overlap of the two hit sets at this stringent hit threshold is relatively small. Only ~28% of the hits from the W1282X screen were also hits in the Y122X screen. The overlap increases to ~50% if compounds are included that in the second screen achieve only a less stringent hit criterion, that is, horseradish peroxidase (HRP) activity greater than three standard deviations above the mean of the vehicle. Our data suggest that personalization may not need to address individual genotypes, but that patients with different CFTR PTC mutations could benefit from the same medicines.

PMID: 28376702 [PubMed - as supplied by publisher]

Clinical implications of Pseudomonas aeruginosa location in the lungs of patients with cystic fibrosis.

J Clin Pharm Ther. 2017 Apr 04;:

Authors: Moore JE, Mastoridis P

Abstract
WHAT IS KNOWN AND OBJECTIVE: Pseudomonas aeruginosa is the leading cause of lung infection in patients with cystic fibrosis (CF) and is associated with significant morbidity and mortality. Antibiotics are regarded as the foundational pharmacological treatment for the suppressive management of chronic P. aeruginosa infections and to eradicate the first infection by P. aeruginosa. Inhalation remains a preferred route for drug administration, providing direct access to the site of infection while minimizing systemic side effects. Effective suppressive management of P. aeruginosa infections, however, requires an understanding of the location of the bacteria in the lungs and consideration of the factors that could limit access of the inhaled antibiotic to the infected area. This review provides a systematic assessment of the scientific literature to gain insight into the location of P. aeruginosa in the lungs of patients with CF and its clinical implications. The characteristics of antibiotic inhalation systems are also discussed in this context.
METHODS: We reviewed evidence-based literature from both human and animal studies in which P. aeruginosa lung location was reported. Relevant publications were identified through a screening strategy and summarized by reported P. aeruginosa location.
RESULTS AND DISCUSSION: Most areas of the conductive and respiratory zones of the lungs are susceptible to P. aeruginosa colonization. Deposition of an inhaled antibiotic is dependent on the device and formulation characteristics, as well as the ability of the patient to generate sufficient inhaled volume. As patients with CF often experience a decline in lung function, the challenge is to ensure that the inhaled antibiotic can be delivered throughout the bronchial tree.
WHAT IS NEW AND CONCLUSION: An effective drug delivery system that can target P. aeruginosa in both the respiratory and conductive zones is required. The chosen inhalation device should also offer a drug formulation that can be quickly and effectively delivered to specific lung locations, with minimal inspiratory effort from the patient.

PMID: 28374433 [PubMed - as supplied by publisher]

Modelling the bronchial barrier in pulmonary drug delivery: a human bronchial epithelial cell line supplemented with human tracheal mucus.

Eur J Pharm Biopharm. 2017 Mar 31;:

Authors: Murgia X, Yasar H, Carvalho-Wodarz C, Loretz B, Gordon S, Schwarzkopf K, Schaefer U, Lehr CM

Abstract
The airway epithelium together with the mucus layer coating it forms a protective system that efficiently filters and removes potentially harmful particles contained in inhaled air. The same mechanism, however, serves to entrap particulate drug carriers, precluding their interaction with their target. The mucus barrier is often neglected in in vitro testing setups employed for the assessment of pulmonary drug delivery strategies. Therefore, our aim was to more accurately model the bronchial barrier, by developing an in vitro system comprising a tight epithelial cell layer which may be optionally supplemented with a layer of human tracheal mucus. To form the epithelium in vitro, we used the cystic fibrosis cell line CFBE41o-, which can be grown as monolayers on Transwell(®) supports, expressing tight junctions as well as relevant transport proteins. In contrast to the cell line Calu-3, however, CFBE41o- does not produce mucus. Therefore, native human mucus, obtained from tracheal tubes of patients undergoing elective surgery, was used as a supplement. The compatibility of CFBE41o- cells with the human mucus was addressed with the MTT assay, and confirmed by fluorescein diacetate/propidium iodide live/dead staining. Moreover, the CFBE41o- cells retained their epithelial barrier properties after being supplemented with mucus, as evidenced by the high trans-epithelial electrical resistance values (∼1000 Ω∗cm(2)) together with a continued low level of paracellular transport of sodium fluorescein. Fluorescently-labelled chitosan-coated PLGA nanoparticles (NP, ∼168 nm) were used as a model drug delivery system to evaluate the suitability of this in vitro model for studying mucus permeation and cell uptake. Comparing CFBE41o- cell monolayers with and without mucus, resp., showed that the NP uptake was dramatically reduced in the presence of mucus. This model may therefore be used as a tool to study potential mucus interactions of aerosolized drugs, and more specifically NP-based drug delivery systems designed to exert their effect in the bronchial region.

PMID: 28373109 [PubMed - as supplied by publisher]

Cystic fibrosis in the era of precision medicine.

Paediatr Respir Rev. 2017 Mar 09;:

Authors: Paranjape SM, Mogayzel PJ

Abstract
The treatment of people with cystic fibrosis (CF) has been transformed by the availability of drugs that target the basic chloride defect in the disease. The use of drugs that target specific molecular defects embodies the goals of precision medicine, which incorporate preventive and therapeutic strategies and takes into account differences among individuals. However, the entirety of CF care, from diagnosis to understanding the clinical phenotype and developing a therapeutic strategy, depends on taking into account individual characteristics to achieve optimal outcomes. Future therapies are likely to be even more individualized ushering in a new era of precision medicine.

PMID: 28372929 [PubMed - as supplied by publisher]

Regulatory T Cell Specificity Directs Tolerance versus Allergy against Aeroantigens in Humans.

Cell. 2016 11 03;167(4):1067-1078.e16

Authors: Bacher P, Heinrich F, Stervbo U, Nienen M, Vahldieck M, Iwert C, Vogt K, Kollet J, Babel N, Sawitzki B, Schwarz C, Bereswill S, Heimesaat MM, Heine G, Gadermaier G, Asam C, Assenmacher M, Kniemeyer O, Brakhage AA, Ferreira F, Wallner M, Worm M, Scheffold A

Abstract
FOXP3+ regulatory T cells (Tregs) maintain tolerance against self-antigens and innocuous environmental antigens. However, it is still unknown whether Treg-mediated tolerance is antigen specific and how Treg specificity contributes to the selective loss of tolerance, as observed in human immunopathologies such as allergies. Here, we used antigen-reactive T cell enrichment to identify antigen-specific human Tregs. We demonstrate dominant Treg-mediated tolerance against particulate aeroallergens, such as pollen, house dust mites, and fungal spores. Surprisingly, we found no evidence of functional impairment of Treg responses in allergic donors. Rather, major allergenic proteins, known to rapidly dissociate from inhaled allergenic particles, have a generally reduced capability to generate Treg responses. Most strikingly, in individual allergic donors, Th2 cells and Tregs always target disparate proteins. Thus, our data highlight the importance of Treg antigen-specificity for tolerance in humans and identify antigen-specific escape from Treg control as an important mechanism enabling antigen-specific loss of tolerance in human allergy.

PMID: 27773482 [PubMed - indexed for MEDLINE]

Pseudomonas eradication and clinical effectivness of Ivacaftor in four Hispanic patients with S549N.

Pediatr Pulmonol. 2017 Apr 03;:

Authors: Strang A, Fischer AJ, Chidekel A

Abstract
Ivacaftor was approved for rarer class-III CFTR mutations including S549N in 2014. Since these mutations are uncommon, ongoing reports of patient experiences with Ivacaftor and these mutations are important. This case series describes the clinical effectiveness (including airway infection status, lung function, and growth) of Ivacaftor therapy in four pediatric Hispanic patients with S549N and F508del over 24 months. In these patients, Ivacaftor was highly efficacious with no further Pseudomonas-positive cultures despite prior chronic colonization in three patients as well as notable improvements in lung function and growth. The remarkable improvements in lung function and growth were similar to G551D patients with more striking changes in airway infection status. Pediatr Pulmonol. © 2016 Wiley Periodicals, Inc.

PMID: 28371569 [PubMed - as supplied by publisher]

Patient and Provider Perspectives on Communication About Body Image With Adolescents and Young Adults With Cystic Fibrosis.

J Pediatr Psychol. 2017 Mar 24;:

Authors: Helms SW, Christon LM, Dellon EP, Prinstein MJ

Abstract
Objective : This mixed-methods study examined perspectives of adolescents and young adults (AYAs) with cystic fibrosis (CF) and health care providers on body image communication. Interviews and questionnaires were completed by 20 AYAs and 28 providers. Although 85% of patients reported they had never had a body image conversation with a health care provider, 74% of providers reported discussing this topic with patients. Patients and providers described body image as an important issue, which should be discussed comfortably and supportively. However, patients often preferred to discuss body image as a distinct topic, separate from physical health, whereas providers preferred integrating body image conversations within weight- and health-based discussions.  Body image is an important topic for AYAs with CF that often goes unaddressed or addressed in ways that are less preferred by patients. Providers should reduce barriers to effective communication about this important topic, particularly through increased awareness of AYA preferences.

PMID: 28369522 [PubMed - as supplied by publisher]

Nonsense Suppression as an Approach to Treat Lysosomal Storage Diseases.

Diseases. 2016 Dec;4(4):

Authors: Keeling KM

Abstract
In-frame premature termination codons (PTCs) (also referred to as nonsense mutations) comprise ~10% of all disease-associated gene lesions. PTCs reduce gene expression in two ways. First, PTCs prematurely terminate translation of an mRNA, leading to the production of a truncated polypeptide that often lacks normal function and/or is unstable. Second, PTCs trigger degradation of an mRNA by activating nonsense-mediated mRNA decay (NMD), a cellular pathway that recognizes and degrades mRNAs containing a PTC. Thus, translation termination and NMD are putative therapeutic targets for the development of treatments for genetic diseases caused by PTCs. Over the past decade, significant progress has been made in the identification of compounds with the ability to suppress translation termination of PTCs (also referred to as readthrough). More recently, NMD inhibitors have also been explored as a way to enhance the efficiency of PTC suppression. Due to their relatively low threshold for correction, lysosomal storage diseases are a particularly relevant group of diseases to investigate the feasibility of nonsense suppression as a therapeutic approach. In this review, the current status of PTC suppression and NMD inhibition as potential treatments for lysosomal storage diseases will be discussed.

PMID: 28367323 [PubMed - in process]

Corrector VX-809 Promotes Interactions Between Cytoplasmic Loop One and the First Nucleotide-Binding Domain of CFTR.

Biochem Pharmacol. 2017 Mar 30;:

Authors: Loo TW, Clarke DM

Abstract
A large number of correctors have been identified that can partially repair defects in folding, stability and trafficking of CFTR processing mutants that cause cystic fibrosis (CF). The best corrector, VX-809 (Lumacaftor), has shown some promise when used in combination with a potentiator (Ivacaftor). Understanding the mechanism of VX-809 is essential for development of better correctors. Here, we tested our prediction that VX-809 repairs folding and processing defects of CFTR by promoting interactions between the first cytoplasmic loop (CL1) of transmembrane domain 1 (TMD1) and the first nucleotide-binding domain (NBD1). To investigate whether VX-809 promoted CL1/NBD1 interactions, we performed cysteine mutagenesis and disulfide cross-linking analysis of Cys-less TMD1 (residues 1-436) and ΔTMD1 (residues 437-1480; NBD1-R-TMD2-NBD2) truncation mutants. It was found that VX-809, but not bithiazole correctors, promoted maturation (exited endoplasmic reticulum for addition of complex carbohydrate in the Golgi) of the ΔTMD1 truncation mutant only when it was co-expressed in the presence of TMD1. Expression in the presence of VX-809 also promoted cross-linking between R170C (in CL1 of TMD1 protein) and L475C (in NBD1 of the ΔTMD1 truncation protein). Expression of the ΔTMD1 truncation mutant in the presence of TMD1 and VX-809 also increased the half-life of the mature protein in cells. The results suggest that the mechanism by which VX-809 promotes maturation and stability of CFTR is by promoting CL1/NBD1 interactions.

PMID: 28366727 [PubMed - as supplied by publisher]

Indications for lung resection surgery and lung transplant in South American children with cystic fibrosis.

Paediatr Respir Rev. 2017 Feb 16;:

Authors: Villac Adde F, Vidal Campos S, de Oliveira Braga Teixeira RH, Rodrigues JC

Abstract
The current available literature evaluating lung resection surgery and lung transplantation in children with cystic fibrosis (CF) was reviewed through a PubMed search and references from selected studies were additionally included. Pulmonary resections, i.e. lobectomy, segmentectomy, and pneumonectomy, are seldom performed in CF. The main indications, in patients with a forced expiratory volume in 1second (FEV1) that is greater than 30% predicted, are localized bronchiectasis/atelectasis, severe hemoptysis, and bronchopleural fistula refractory to medical management. The potential benefits are decreased symptoms and pulmonary exacerbations, and an improved quality of life. Pre and postoperative intensive care is mandatory for surgical candidates. The risk of death should be taken into account when the procedure is considered. Selection for lung transplantation (LTx) candidates in children with CF in South America follows the International Society for Heart and Lung Transplantation (ISHLT) criteria. When compared to adults with CF, a poorer survival rate after LTx in children with CF has been observed in the literature, as well as in our LTx center in Brazil, reasons for which are still unknown. The main complications after LTx in children are early and late acute rejection, and infections. LTx is a therapeutic option for eligible children with CF, fulfilling the lung transplant candidacy criteria, as post-transplant survival rates are increasingly improving due to better management of the transplanted patient.

PMID: 28366682 [PubMed - as supplied by publisher]

Telemedicine is the way forward for the management of Cystic Fibrosis- The case against.

Paediatr Respir Rev. 2017 Mar 14;:

Authors: Lenney W

Abstract
It is reasonable to suggest that Telemedicine could help in the management of chronic diseases by giving patients more flexibility to remain at home with opportunities to forward electronic data to healthcare professionals, reduce hospital emergency attendances and reduce overall costs. The reality, particularly in cystic fibrosis care, is this has not happened. There is concern that home-generated lung function data is of poor quality and virtually no studies show improved outcomes. The UK has a poor record in developing novel IT programmes and we need many more well designed clinical studies in Telemedicine before wading in with ill-conceived expensive plans just because the idea seems interesting.

PMID: 28366680 [PubMed - as supplied by publisher]

Efficient Derivation of Functional Human Airway Epithelium from Pluripotent Stem Cells via Temporal Regulation of Wnt Signaling.

Cell Stem Cell. 2017 Mar 22;:

Authors: McCauley KB, Hawkins F, Serra M, Thomas DC, Jacob A, Kotton DN

Abstract
Effective derivation of functional airway organoids from induced pluripotent stem cells (iPSCs) would provide valuable models of lung disease and facilitate precision therapies for airway disorders such as cystic fibrosis. However, limited understanding of human airway patterning has made this goal challenging. Here, we show that cyclical modulation of the canonical Wnt signaling pathway enables rapid directed differentiation of human iPSCs via an NKX2-1(+) progenitor intermediate into functional proximal airway organoids. We find that human NKX2-1(+) progenitors have high levels of Wnt activation but respond intrinsically to decreases in Wnt signaling by rapidly patterning into proximal airway lineages at the expense of distal fates. Using this directed approach, we were able to generate cystic fibrosis patient-specific iPSC-derived airway organoids with a defect in forskolin-induced swelling that is rescued by gene editing to correct the disease mutation. Our approach has many potential applications in modeling and drug screening for airway diseases.

PMID: 28366587 [PubMed - as supplied by publisher]

Current characteristics, challenges and coping strategies of young people with cystic fibrosis as they transition to adulthood.

Clin Med (Lond). 2017 Apr;17(2):121-125

Authors: Askew K, Bamford J, Hudson N, Moratelli J, Miller R, Anderson A, Doe S, Bourke SJ

Abstract
This study provides detailed data on the current characteristics, perceptions and outcomes of 45 young people with cystic fibrosis (CF) as they transition into adulthood. Although many had severe disease, they generally coped well, found attendance at a transition clinic helpful and welcomed the increased independence of an adult healthcare environment. Levels of psychological distress were low with only 15.6% having anxiety and 6.7% depression. The main psychological coping strategy used was optimistic acceptance. Overall, most remained stable after transfer but 33% had some decline in lung function and 9% in nutritional status, requiring intensification of treatment. They had high levels of satisfaction with their relationships and life situations and 76% were in employment or education. These results are encouraging and as life expectancy improves, young adults with CF are coping well with transition into adulthood.

PMID: 28365620 [PubMed - in process]