Nucleic Acid Therapies for Cystic Fibrosis.

Nucleic Acid Ther. 2017 Nov 21;:

Authors: Sasaki S, Guo S

Abstract
Nucleic acid therapeutics are an established class of drugs that enable specific targeting of a gene of interest. This diverse family of drugs includes antisense oligonucleotides, siRNAs, and mRNA replacement therapies, which can elicit both gene repression and activation, primarily at the RNA level. Recent advances in medicinal chemistry have increased drug potency and enhanced delivery and distribution to a broad array of tissue and cell types. A key advantage of nucleic acid therapeutics is in their application to monogenic diseases. Cystic fibrosis (CF) is one such disease that affects ∼70,000 people globally. This severe disease is an excellent candidate for nucleic acid therapies, as it is due to a genetic defect in a single epithelial chloride channel. Although CF affects many tissues, the primary cause of patient mortality is lung disease. Here we review the various nucleic acid therapeutic modalities and their mechanisms of action, the opportunities and challenges associated with application of nucleic acid drugs to the lung pathology of CF, and the current state and prospects for nucleic acid drugs for the treatment of CF.

PMID: 29160746 [PubMed - as supplied by publisher]

Use of ceftolozane-tazobactam in a cystic fibrosis patient with multidrug-resistant pseudomonas infection and renal insufficiency.

Respir Med Case Rep. 2018;23:8-9

Authors: Stokem K, Zuckerman JB, Nicolau DP, Wungwattana M, Sears EH

Abstract
We report the successful use of ceftolozane/tazobactam (C/T) to treat a pulmonary exacerbation in a 35 year old female, post lung transplant, with cystic fibrosis (CF), malnutrition, chronic kidney disease, and multi-drug resistant Pseudomonas aeruginosa infection (MDR PSA). Given the complexity of the clinical profile, we measured drug levels of C/T during treatment of her current exacerbation to determine pharmacokinetics. The patient achieved an estimated ceftolozane peak of 174.1 μg/mL and trough of 9.2 μg/mL. Serum half-life was found to be slightly shorter than previously reported in normal subjects, (2.3 hr. vs. 2.6 hr.) despite the presence of renal insufficiency. Treatment resulted in improvement in serum inflammatory markers and symptoms and was well-tolerated.

PMID: 29159032 [PubMed]

High-throughput screening identifies FAU protein as a regulator of mutant cystic fibrosis transmembrane conductance regulator channel.

J Biol Chem. 2017 Nov 20;:

Authors: Tomati V, Pesce E, Caci E, Sondo E, Scudieri P, Marini M, Amato F, Castaldo G, Ravazzolo R, Galietta LJ, Pedemonte N

Abstract
In cystic fibrosis (CF), deletion of phenylalanine 508 (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel causes misfolding and premature degradation. One possible approach to reducing CF's detrimental health effects could be the identification of proteins whose suppression rescues F508del-CFTR function in bronchial epithelial cells. However, searches for these potential targets have not yet been conducted, particularly in a relevant airway background using a functional readout. To identify proteins associated with F508del-CFTR processing, we used a high-throughput functional assay to screen an siRNA library targeting 6,650 different cellular proteins. We identified 37 proteins whose silencing significantly rescued F508del- CFTR activity, as indicated by enhanced anion transport through the plasma membrane. These proteins included FAU, UBE2I, UBA52, MLLT6, UBA2, CHD4, PLXNA1, and TRIM24, among others. We focused our attention on FAU, a poorly characterized protein with unknown function. FAU knockdown increased the plasma membrane targeting and function of F508del-CFTR, but not of wildtype CFTR. Investigation into the mechanism of action revealed a preferential physical interaction of FAU with mutant CFTR, leading to its degradation. FAU and other proteins identified in our screening may offer a therapeutically relevant panel of drug targets to correct basic defects in F508del-CFTR processing.

PMID: 29158263 [PubMed - as supplied by publisher]

Development and electronic validation of the revised Cystic Fibrosis Questionnaire (CFQ-R Teen/Adult): New tool for monitoring psychosocial health in CF.

J Cyst Fibros. 2017 Nov 17;:

Authors: Solé A, Olveira C, Pérez I, Hervás D, Valentine V, Baca Yepez AN, Olveira G, Quittner AL

Abstract
BACKGROUND: The Cystic Fibrosis Questionnaire-Revised (CFQ-R+14) is a disease-specific, health-related quality of life instrument for cystic fibrosis (CF) patients ≥14years. We have developed a Spanish electronic version of the CFQ-R (e-CFQ-R+14 Spain). Our aim was to compare the paper and electronic versions and to validate the electronic version.
METHODS: Fifty CF patients completed the study. All answered the paper and electronic versions on day 1 and repeated the e-CFQR version 15days later.
RESULTS: Concordance between the electronic and paper copy versions was high, with correlations above 0.9 in all domains. Test-retest reliability of the e-CFQ-R results was strong, with coefficients ranging from 0.8 to 0.9.
CONCLUSIONS: The e-CFQ-R version is reliable and valid and can replace the paper copy, thus simplifying the assessment of quality of life. It also provides immediate results with no errors in scoring. It is a useful new tool in CF care.

PMID: 29157922 [PubMed - as supplied by publisher]

Pooling of bronchoalveolar lavage in children with cystic fibrosis does not adversely affect the microbiological yield or sensitivity in detecting pulmonary inflammation.

J Cyst Fibros. 2017 Nov 17;:

Authors: McNally P, O'Rourke J, Fantino E, Chacko A, Pabary R, Turnbull A, Grant T, O'Sullivan N, Wainwright C, Linnane B, Davies JC, Sly PD

Abstract
BACKGROUND: Bronchoalveolar lavage (BAL) is a potentially useful outcome measure for clinical trials in children with CF but its use is limited by variations in approach internationally. We sought to determine if pooling adversely affected the diagnostic properties of BAL.
METHODS: Children undergoing bronchoscopy for clinical reasons were included. A multi-step study protocol ensured BAL was collected and analysed both separately and as a pooled fluid.
RESULTS: Eighty-five children (53 CF, 32 control) were recruited. There was a high level of concordance between pooled and non-pooled samples in terms of organism identification (76%). There was good agreement (Bland Altman) between the two methods in terms of detection of inflammation independent of centre, microbiological concordance or disease status. Bi-directional variability in IL-8 levels between pooled and non-pooled samples was seen. Free neutrophil elastase (NE) was detected in 4 cases in pooled lavage when absent in non-pooled lavage. Levels of interleukin-8 (IL-8) were similar between the two groups with pooled samples showing a greater spread of values.
CONCLUSIONS: Pooling of BAL in children does not negatively impact on either the detection of pulmonary infection or inflammation or the observed relationship between infection and inflammation. Intra-patient variability in BAL IL-8 levels suggests regional differences in inflammation.

PMID: 29157921 [PubMed - as supplied by publisher]

A practical molecular identification of nonfermenting Gram-negative bacteria from cystic fibrosis.

Braz J Microbiol. 2017 Nov 04;:

Authors: Capizzani CPDC, Caçador NC, Marques EA, Levy CE, Tonani L, Torres LAGMM, Darini ALDC

Abstract
Identification of nonfermenting Gram-negative bacteria (NFGNB) of cystic fibrosis patients is hard and misidentification could affect clinical outcome. This study aimed to propose a scheme using polymerase chain reaction to identify NFGNB. This scheme leads to reliable identification within 3 days in an economically viable manner when compared to other methods.

PMID: 29157900 [PubMed - as supplied by publisher]

Optimized LC-MS/MS Method for the High-throughput Analysis of Clinical Samples of Ivacaftor, Its Major Metabolites, and Lumacaftor in Biological Fluids of Cystic Fibrosis Patients.

J Vis Exp. 2017 Oct 15;(128):

Authors: Schneider EK, Reyes-Ortega F, Li J, Velkov T

Abstract
Defects in the cystic fibrosis trans-membrane conductance regulator (CFTR) are the cause of cystic fibrosis (CF), a disease with life-threatening pulmonary manifestations. Ivacaftor (IVA) and ivacaftor-lumacaftor (LUMA) combination are two new breakthrough CF drugs that directly modulate the activity and trafficking of the defective CFTR-protein. However, there is still a dearth of understanding on pharmacokinetic/pharmacodynamic parameters and the pharmacology of ivacaftor and lumacaftor. The HPLC-MS technique for the simultaneous analysis of the concentrations of ivacaftor, hydroxymethyl-ivacaftor, ivacaftor-carboxylate, and lumacaftor in biological fluids in patients receiving standard ivacaftor or ivacaftor-lumacaftor combination therapy has previously been developed by our group and partially validated to FDA standards. However, to allow the high-throughput analysis of a larger number of patient samples, our group has optimized the reported method through the use of a smaller pore size reverse-phase chromatography column (2.6 µm, C8 100 Å; 50 x 2.1 mm) and a gradient solvent system (0-1 min: 40% B; 1-2 min: 40-70% B; 2-2.7 min: held at 70% B; 2.7-2.8 min: 70-90% B; 2.8-4.0 min: 90% B washing; 4.0-4.1 min: 90-40% B; 4.1-6.0 min: held at 40% B) instead of an isocratic elution. The goal of this study was to reduce the HPLC-MS analysis time per sample dramatically from ~15 min to only 6 min per sample, which is essential for the analysis of a large amount of patient samples. This expedient method will be of considerable utility for studies into the exposure-response relationships of these breakthrough CF drugs.

PMID: 29155707 [PubMed - in process]

Enzyme replacement therapy for infantile-onset Pompe disease.

Cochrane Database Syst Rev. 2017 Nov 20;11:CD011539

Authors: Chen M, Zhang L, Quan S

Abstract
BACKGROUND: Infantile-onset Pompe disease is a rare and progressive autosomal-recessive disorder caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). Current treatment involves enzyme replacement therapy (with recombinant human alglucosidase alfa) and symptomatic therapies (e.g. to control secretions). Children who are cross-reactive immunological material (CRIM)-negative require immunomodulation prior to commencing enzyme replacement therapy.Enzyme replacement therapy was developed as the most promising therapeutic approach for Pompe disease; however, the evidence is lacking, especially regarding the optimal dose and dose frequency.
OBJECTIVES: To assess the effectiveness, safety and appropriate dose regimen of enzyme replacement therapy for treating infantile-onset Pompe disease.
SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register, which is compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the Cochrane Central Register of Controlled Trials (CENTRAL), Embase (Ovid), PubMed and LILACS, and CBM, CNKI, VIP, and WANFANG for literature published in Chinese. In addition, we searched three online registers: WHO International Clinical Trials Registry Platform ClinicalTrials.gov, and www.genzymeclinicalresearch.com. We also searched the reference lists of relevant articles and reviews.Date of last search of the Group's Inborn Errors of Metabolism Trials Register: 24 November 2016.
SELECTION CRITERIA: Randomized and quasi-randomized controlled trials of enzyme replacement therapy in children with infantile-onset Pompe disease.
DATA COLLECTION AND ANALYSIS: Two authors independently selected relevant trials, assessed the risk of bias and extracted data. We contacted investigators to obtain important missing information.
MAIN RESULTS: We found no trials comparing the effectiveness and safety of enzyme replacement therapy to another intervention, no intervention or placebo.We found one trial (18 participants) that fulfilled the selection criteria, comparing different doses of alglucosidase alfa. The trial provided low-quality evidence (this was a small trial, there were no numerical results available by dose group, random sequence generation and allocation concealment were unclear, and there was a lack of blinding). The duration of alglucosidase alfa treatment ranged from 52 weeks (the length of the original study) to up to three years (including the extended phase of the trial), with a median duration of treatment being 2.3 years.The trial only reported that clinical responses including cardiac function and motor development, as well as the proportion of children that were free of invasive ventilation, were similar in the 20 mg/kg every two weeks and the 40 mg/kg every two weeks groups (low-quality evidence). Long-term alglucosidase alfa treatment markedly extended survival as well as ventilation-free survival and improved cardiomyopathy (low-quality evidence). In relation to the number of children experiencing one or more infusion-related events, there was no significant difference between dose groups, risk ratio 0.83 (95% confidence interval 0.40 to 1.76) (low-quality of evidence). However, of note, at 52 weeks, five children in the 20 mg/kg every two weeks dose group experienced a total of 41 mild or moderate (none severe) infusion-related events and the six children in the 40 mg/kg every two weeks dose group experienced a total of 123 infusion-related events. By the end of the extended phase of the trial, five children in the 20 mg/kg every two weeks dose group experienced a total of 47 infusion-related events and the six children in the 40 mg/kg every two weeks dose group experienced a total of 177 infusion-related events. The trial was supported by the Genzyme Corporation.
AUTHORS' CONCLUSIONS: The search found no trials comparing the effectiveness and safety of enzyme replacement therapy to another intervention, no intervention or placebo. One small randomized controlled trial provided no robust evidence for which dosing schedule of alglucosidase alfa was more effective to treat infantile-onset Pompe disease. It is not deemed ethical to proceed with new placebo-controlled trials, therefore a randomized controlled trial with a large sample size comparing different dosing schedules of enzyme replacement therapy is needed. The main clinical outcomes (i.e. cardiac function, invasive ventilation, survival, motor development, adverse events (e.g. the development of antibodies)) should be standardized when evaluated and reported.

PMID: 29155436 [PubMed - as supplied by publisher]

Green synthesis of anisotropic gold nanoparticles using hordenine and their antibiofilm efficacy against Pseudomonas aeruginosa.

IET Nanobiotechnol. 2017 Dec;11(8):987-994

Authors: Rajkumari J, Meena H, Gangatharan M, Busi S

Abstract
Pseudomonas aeruginosa is a notorious pathogen that causes biofilm aided infections in patients with cystic fibrosis and burn wounds, resulting in significant mortality in immunocompromised individuals. This study reports a novel one-step biosynthesis of gold nanoparticles using phytocompound, hordenine (HD), as a reducing and capping agent. The synthesis of the anisotropic hordenine-fabricated gold nanoparticles (HD-AuNPs) with an average particle size of 136.87 nm was achieved within 12 h of incubation at room temperature. Both HD and HD-AuNPs exhibited significant antibiofilm activity against P. aeruginosa PAO1, although greater biofilm inhibition was observed for the nanoparticles as compared to hordenine alone. In the microtitre plate assay and tube method, the nanoparticles significantly inhibited the biofilm formation by 73.69 and 78.41%, respectively. The exopolysaccharide production by the test pathogen was arrested by 68.46% on treatment with the nanoparticles. Further, the effect of HD and HD-AuNPs on the biofilm architecture of P. aeruginosa was revealed by light and confocal laser-scanning microscopy micrographs. The overall results of this study suggested the synergistic antibiofilm effect of AuNPs and HD for the treatment of chronic bacterial infections caused by biofilms forming pathogens.

PMID: 29155399 [PubMed - in process]

Resveratrol dimer trans-ε-viniferin prevents rotaviral diarrhea in mice by inhibition of the intestinal calcium-activated chloride channel.

Pharmacol Res. 2017 Nov 14;:

Authors: Yu B, Jiang Y, Zhang B, Yang H, Ma T

Abstract
We previously identified, by a natural-product screen, resveratrol oligomers as inhibitors of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. Here, we report the resveratrol dimer trans-ε-viniferin (TV) and tetramer r-2-viniferin (RV) as inhibitors of the intestinal calcium-activated chloride channel (CaCC) and demonstrate their antisecretory efficacy in a neonatal mouse model of rotaviral diarrhea. Short-circuit measurements show inhibition of CaCC current in the human colonic cell line HT-29 by TV and RV with IC50∼1 and 20μM, respectively. TV primarily inhibited the physiologically relevant, long-term CaCC current following agonist stimulation, without effect on cytoplasmic Ca(2+) signaling. TV and RV inhibited short-circuit current in mouse colon as well. In a neonatal mouse model of rotaviral secretory diarrhea produced by oral inoculation with rotavirus, 2μg TV or 11μg RV inhibited secretory diarrhea by >50%, without effect on the rotaviral infection. Our results support the antisecretory efficacy of non-toxic, natural-product resveratrol oligomers for diarrheas produced by CaCC activation. Because these compounds also inhibit the CFTR chloride channel, they may be useful for antisecretory therapy of a wide range of diarrheas.

PMID: 29155014 [PubMed - as supplied by publisher]

Adults with cystic fibrosis have deficits in bone structure and strength at the distal tibia despite similar size and measuring standard and relative sites.

Bone. 2017 Nov 14;:

Authors: Nishiyama KK, Agarwal S, Kepley A, Rosete F, Hu Y, Guo XE, Keating CL, DiMango EA, Shane E

Abstract
Individuals with cystic fibrosis (CF) have lower bone mineral density (BMD) by DXA and are at higher risk of fracture than healthy controls. However, the 2-dimensional measurement of areal BMD (aBMD) provided by DXA is influenced by bone size and the true extent of the bone deficit is unclear. Our objective was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) and individual trabecula segmentation (ITS) analysis to compare volumetric BMD (vBMD), microarchitecture and estimated strength at the distal radius and tibia in 26 young adults with CF and 26 controls matched for age, gender, and race. To assess the effect of limb length and minimize the confounding effects of size on HR-pQCT outcomes, we scanned participants at both the standard fixed HR-pQCT measurement sites and at a subject-specific relative site that varied according to limb length. CF participants did not differ significantly in age, height, weight, or BMI from controls. Ulnar and tibial lengths were 9mm shorter in CF patients, though differences were not significant. CF patients had significantly lower BMI-adjusted aBMD by DXA at the lumbar spine (8.9%, p<0.01), total hip (11.5%, p<0.01) and femoral neck (14.5%, p<0.01), but not at the forearm. At the fixed radius site, thickness of trabecular plates and torsional stiffness were significantly lower in CF participants than controls. At the relative radius site, only torsional stiffness was significantly lower in CF participants. At the tibia, total, trabecular and cortical vBMD were significantly lower at both fixed and relative sites in CF participants, with fewer, more widely-spaced trabecular plates, lower trabecular connectivity, and lower axial and torsional stiffness. Our results confirm that aBMD is lower at the spine and hip in young adults with CF, independent of BMI and body size. We also conclude that vBMD and stiffness are lower at the weight-bearing tibia. The pathogenesis of these differences in bone density and strength at the tibia appear to be related to trabecular drop-out and reduced trabecular connectivity and to be independent of differences in limb length, as assessed by scanning participants at both standard and relative sites. We concluded that significant deficits in bone structure and strength persist in young adults with CF, despite advances in care that permit them to attain relatively normal height and weight.

PMID: 29154969 [PubMed - as supplied by publisher]

A novel microscopy-based assay identifies extended synaptotagmin-1 (ESYT1) as a positive regulator of anoctamin 1 traffic.

Biochim Biophys Acta. 2017 Nov 15;:

Authors: Lérias JR, Pinto MC, Botelho HM, Awatade NT, Quaresma MC, Silva IAL, Wanitchakool P, Schreiber R, Pepperkok R, Kunzelmann K, Amaral MD

Abstract
An attractive possibility to treat Cystic Fibrosis (CF), a severe condition caused by dysfunctional CFTR, an epithelial anion channel, is through the activation of alternative (non-CFTR) anion channels. Anoctamin 1 (ANO1) was demonstrated to be a Ca(2+)-activated chloride channel (CaCC) and thus of high potential to replace CFTR. Despite that ANO1 is expressed in human lung CF tissue, it is present at the cell surface at very low levels. In addition, little is known about regulation of ANO1 traffic, namely which factors promote its plasma membrane (PM) localization. Here, we generated a novel cellular model, expressing an inducible 3HA-ANO1-eGFP construct, and validated its usage as a microscopy tool to monitor for ANO1 traffic. We demonstrate the robustness and specificity of this cell-based assay, by the identification of siRNAs acting both as ANO1 traffic enhancer and inhibitor, targeting respectively COPB1 and ESYT1 (extended synaptotagmin-1), the latter involved in coupling of the endoplasmic reticulum to the PM at specific microdomains. We further show that knockdown of ESYT1 (and family members ESYT2 and ESYT3) significantly decreased ANO1 current density. This ANO1 cell-based assay constitutes an important tool to be further used in high-throughput screens and drug discovery of high relevance for CF and cancer.

PMID: 29154949 [PubMed - as supplied by publisher]

An Integrated Mathematical Epithelial Cell Model for Airway Surface Liquid Regulation by Mechanical Forces.

J Theor Biol. 2017 Nov 15;:

Authors: Wu D, Boucher RC, Button B, Elston T, Lin CL

Abstract
A robust method based on reverse engineering was utilized to construct the ion-channel conductance functions for airway epithelial sodium channels (ENaC), the cystic fibrosis transmembrane conductance regulator (CFTR), and calcium-activated chloride channels (CaCC). The ion-channel conductance models for both normal (NL) and cystic fibrosis (CF) airway epithelia were developed and then coupled to an adenosine triphosphate (ATP) metabolism model and a fluid transport model (collectively called the integrated cell model) to investigate airway surface liquid (ASL) volume regulation and hence mucus concentration, by mechanical forces in NL and CF human airways. The epithelial cell models for NL and CF required differences in Cl(-) secretion (decreased in CF) and Na(+) absorption (raised in CF) to reproduce behaviors similar to in vitro epithelial cells exposed to mechanical forces (cyclic shear stress, cyclic compressive pressure and cilial strain) and selected modulators of ion channels and ATP release. The epithelial cell models were then used to investigate the effects of mechanical forces and evaporative flux on ASL and mucus homeostasis in both NL and CF airway epithelia. Because of reduced CF ASL volumes, CF mucus concentrations increased and produced a greater dependence of ASL volume regulation on cilia-mucus-ATP release interactions in CF than NL epithelial nodules. Similarly, the CF model was less tolerant to evaporation induced ASL volume reduction at all ATP release rates than the NL model. Consequently, this reverse engineered model appears to provide a robust tool for investigating CF pathophysiology and novel therapies.

PMID: 29154907 [PubMed - as supplied by publisher]

Acute pain perception during different sampling methods for respiratory culture in cystic fibrosis patients.

J Pain Symptom Manage. 2017 Nov 14;:

Authors: Eyns H, De Wachter E, Malfroot A, Vaes P

Abstract
BACKGROUND: Reliable identification of lower respiratory tract pathogens is crucial in the management of cystic fibrosis (CF). As part of another study (NCT02363764) investigating the bacterial yield of three sampling methods: nasal swabs (NS), cough swabs (CS) and (induced) sputum samples ((I)SS) in both expectorating (EPs) and non-expectorating (NEPs) patients with CF, the present study aimed to explore the prevalence of respiratory culture sampling-related pain as assessed by self-report within a cohort of children and adults.
METHODS: Literate patients with CF (>6y) completed a questionnaire on pain perception related to the three aforementioned sampling methods [No/Yes; visual analogue scale for pain "VAS-Pain" (0-10cm)]. Additionally, patients were asked to rank these methods by their own preference without taking into account the presumed bacterial yield.
RESULTS: In total, 119 questionnaires were returned. In the EPs-group, CS was most frequently (n%;mean VAS-Pain if pain [range]) reported as painful method: overall (n=101)(12.9%;1.8[0.2-4.8]), children (n=41)(22.0%;1.4[0.2-2.7]) and adults (n=60)(6.7%;2.5[0.5-4.8]). Highest pain intensity scores were observed with NS overall (3.0%;2.4[0.3-6.2]) and in children (4.9%;3.3[0.3-6.2]), but not in adults (1.7%;0.6[-]). NEPs-children (n=17) reported ISS most frequently and as most painful sampling method (17.6%;2.0[1.0-4.0]). The only NEP-adult did not perceive pain. NEPs preferred NS>CS>ISS [61.1%,33.3%,5.6%,resp.(p=0.001)] as primary sampling method, whereas EPs preferred SS>NS>CS [65.7%,26.3%,8.1%,resp.(p<0.0001)]. Patients' preference for a specific method inversely correlated to pain perception and intensity in EPs [φ=-0.155(p=0.007); ρ=-0.926(p=0.008), resp.] but not in NEPs [φ=-0.226(p=0.097); ρ=-0.135(p=0.798), resp.].
CONCLUSION: A relatively large range of pain experiences was observed in patients with CF during respiratory culture sampling, which underlines the importance of individual pain assessment. Nevertheless, clinicians can confidently choose the sampling method based on validity over patients' preference.

PMID: 29154891 [PubMed - as supplied by publisher]

Streptococcus pneumoniae TIGR4 Phase-Locked Opacity Variants Differ in Virulence Phenotypes.

mSphere. 2017 Nov-Dec;2(6):

Authors: Oliver MB, Basu Roy A, Kumar R, Lefkowitz EJ, Swords WE

Abstract
Streptococcus pneumoniae (pneumococcus) is a leading human pathogen that can cause serious localized and invasive diseases. Pneumococci can undergo a spontaneous and reversible phase variation that is reflected in colony opacity and which allows the population to adapt to different host environments. Generally, transparent variants are adapted for nasopharyngeal colonization, whereas opaque variants are associated with invasive disease. In recent work, colony phase variation was shown to occur by means of recombination events to generate multiple alleles of the hsdS targeting domain of a DNA methylase complex, which mediates epigenetic changes in gene expression. A panel of isogenic strains were created in the well-studied S. pneumoniae TIGR4 background that are "locked" in the transparent (n = 4) or opaque (n = 2) colony phenotype. The strains had significant differences in colony size which were stable over multiple passages in vitro and in vivo. While there were no significant differences in adherence for the phase-locked mutant strains to immortalized epithelial cells, biofilm formation and viability were reduced for the opaque variants in static assays. Nasopharyngeal colonization was stable for all strains, but the mortality rates differed between them. Transcript profiling by transcriptome sequencing (RNA-seq) analyses revealed that the expression levels of certain virulence factors were increased in a phase-specific manner. As epigenetic regulation of phase variation (often referred to as "phasevarion") is emerging as a common theme for mucosal pathogens, these results serve as a model for future studies of host-pathogen interactions. IMPORTANCE A growing number of bacterial species undergo epigenetic phase variation due to variable expression or specificity of DNA-modifying enzymes. For pneumococci, this phase variation has long been appreciated as being revealed by changes in colony opacity, which are reflected in changes in expression or accessibility of factors on the bacterial surface. Recent work showed that recombination-generated variation in alleles of the HsdS DNA methylase specificity subunit mediated pneumococcal phase variation. We generated phase-locked populations of S. pneumoniae TIGR4 expressing a single nonvariant hsdS allele and observed significant differences in gene expression and virulence. These results highlight the importance of focused pathogenesis studies within specific phase types. Moreover, the generation of single-allele hsdS constructs will greatly facilitate such studies.

PMID: 29152579 [PubMed]

Effect of inhaled steroids on clinical and inflammatoryparameters in children with cystic fibrosis

Turk J Med Sci. 2017 11 13;47(5):1432-1440

Authors: Uyan ZS, Ünlügüzel Üstün G, Haklar G, Çakır E, Oktem S, Ersu R, Karadağ BT, Karakoç F, Dağlı E

Abstract
Background/aim: The effectiveness of inhaled corticosteroids (ICSs) in cystic fibrosis (CF) is controversial. The aim of this study was to investigate the effect of an ICS on bronchial hyperreactivity (BHR), oxidative status, and clinical and inflammatory parameters in CF patients. Materials and methods: CF patients were randomized to receive either 2 mg/day nebulized budesonide or 0.9% normal saline as placebo for 8 weeks. Results: Twenty-nine CF patients (mean age: 10.5 ± 2.9 years) were enrolled in the study. There was no statistically significant difference between the two groups at the end of 8 weeks in terms of symptoms, pulmonary function, BHR, oxidative burst, hs-CRP, or ESR. Although there was a significant decrease in malondialdehyde levels in both groups, there was no difference between the two groups. Percentage of neutrophils in the sputum of patients decreased in the budesonide group (P = 0.006). Although sputum IL-8 levels significantly increased in both groups, there was no statistically significant difference between the two groups. Conclusion: Although there was a significant decrease in the percentage of neutrophils in sputum with budesonide, 8 weeks of 2 mg/day nebulized budesonide was not effective in terms of BHR, oxidative status, or clinical and other inflammatory parameters in children with CF.

PMID: 29151314 [PubMed]

Claudin-10 isoform expression and cation selectivity change with salinity in salt-secreting epithelia of F. heteroclitus.

J Exp Biol. 2017 Nov 17;:

Authors: Marshall WS, Breves JP, Doohan EM, Tipsmark CK, Kelly SP, Robertson GN, Schulte PM

Abstract
To provide insight into claudin (Cldn) tight junction (TJ) protein contributions to branchial salt secretion in marine teleost fishes, this study examined cldn-10 TJ protein isoforms of a euryhaline teleost (mummichog; Fundulus heteroclitus) in association with salinity change and measurements of transepithelial cation selectivity. Mummichogs were transferred from fresh water (FW) to seawater (SW, 35 ‰) and from SW to hypersaline SW (2SW, 60 ‰) in a time course with transfer control groups (FW to FW and SW to SW). FW to SW transfer increased mRNA abundance of cldn-10d and -10e by 2-fold, whilst cldn-10c and -10f transcripts were unchanged. Transfer from SW to 2SW did not alter cldn-10d, and transiently altered cldn-10e abundance, but increased cldn-10c and -10f by 4-fold. This was coincident with an increased number of single-stranded junctions (observed by TEM). For both salinity transfers; (1) cldn-10e mRNA was acutely responsive (i.e. after 24 h), (2) other responsive cldn-10 isoforms increased later (3-7 days), and (3) cystic fibrosis transmembrane conductance regulator (cftr) mRNA was elevated in accordance with established changes in transcellular Cl(-) movement. Changes in mRNA encoding cldn-10c and -10f appeared linked, consistent with the tandem repeat locus in the Fundulus genome, whereas mRNA for tandem cldn-10d and -10e seemed independent of each other. Cation selectivity sequence measured by voltage and conductance responses to artificial SW revealed Eisenman sequence VII: Na(+)>K(+)>Rb(+)∼Cs(+)>Li(+) Collectively, these data support the idea that Cldn-10 TJ proteins create and maintain cation-selective pore junctions in salt-secreting tissues of teleost fishes.

PMID: 29150449 [PubMed - as supplied by publisher]

Caregiver burden of parents of young children with cystic fibrosis.

J Cyst Fibros. 2017 Nov 14;:

Authors: Fitzgerald C, George S, Somerville R, Linnane B, Fitzpatrick P

Abstract
BACKGROUND: There is a paucity of research examining the impact of informal caregiving on parents of young children with cystic fibrosis (CF). The aim of this study was to examine caregiver burden and identify risk factors associated with high caregiver burden in mothers and fathers of young children with CF.
METHODS: This was a cross-sectional study of parents of young children with CF. A total of 213 families were invited to complete the CarerQoL questionnaire, a validated tool composed of two parts: (i) the CarerQol-7D which describes the care situation in terms of the negative and positive effects of caregiving and (ii) the visual analogue scale (VAS) which measures happiness on a scale from 0 to 10 (0=completely unhappy and 10=completely happy). The utility score (US) is a weighted average of the subjective burden derived from the CarerQol-7D (0-100); higher US indicates reduced burden. Differences in mother-father dyad median utility scores were examined using Wilcoxon signed rank test. Generalised linear mixed models were used to identify factors associated with high caregiver burden.
RESULTS: At least one parent from 195 families completed the questionnaire (130 mother-father dyads, 189 mothers and 137 fathers). Fathers had a significantly higher median utility score than mothers [(89.2 (IQR 79.6-96.5) vs. 84.7 (74.5-88.0) p<0.001]. Factors found to be significantly associated with higher caregiver burden were increasing child age (OR 1.02; CI: 1.00-1.04), having a child ever positive for Pseudomonas aeruginosa (Pa) (OR 2.48; CI: 1.30-4.73) and being a mother (OR 1.65; CI: 1.02-2.65).
CONCLUSIONS: This study contributes new findings to the sparse literature on caregiver burden of parents of young children with CF. Increasing child age and infection with Pa, associated with higher morbidity, were linked to greater parental burden.

PMID: 29150357 [PubMed - as supplied by publisher]

[Relationships between COPD and nontuberculous mycobacteria pulmonary infections].

Rev Mal Respir. 2017 Nov 14;:

Authors: Balavoine C, Andréjak C, Marchand-Adam S, Blanc FX

Abstract
Nontuberculous mycobacteria (NTM) pulmonary infections are increasingly frequent in pneumological practice. The diagnosis is based on an association of clinical, microbiological and radiological criteria. Some risk factors for NTM disease have been described, including chronic respiratory diseases, but without specific focus on chronic obstructive pulmonary disease (COPD). COPD patients have more risk to be infected by NTM than patients with the main other chronic respiratory diseases (except cystic fibrosis) (odds ratio [OR] at 15.7 in a case-control study). This NTM pulmonary infection is associated with a greater decline in forced expiratory volume in one second (FEV1) and an increased exacerbation rate. Inhaled corticosteroids (ICS) increase the risk of COPD patients developing an NTM infection (OR at 16.9), especially if ICS are still used at the time of diagnosis. Chronic macrolide treatment could possibly select resistant NTM strains and so could make the treatment clearly more difficult as macrolides are the cornerstone NTM treatment. NTM infections in patients with COPD are probably underestimated and should be kept in mind, particularly when patients have frequent exacerbations and display accelerated respiratory function decline, before implementing ICS or macrolides.

PMID: 29150178 [PubMed - as supplied by publisher]

New Comorbidities in the Changing Face of Cystic Fibrosis Care.

J Cyst Fibros. 2017 Nov;16(6):647-648

Authors: Bonk M, Rey MM, Hadjiliadis D

PMID: 29150009 [PubMed - in process]