Putting CHIP(S) on the Table - Introducing Nitrosothiols (SNOs) into the Arena of CFTR Modulation.

Am J Respir Cell Mol Biol. 2019 Oct 10;:

Authors: Addy C, Schock BC

PMID: 31600091 [PubMed - as supplied by publisher]

Health care provider's experiences, practices, and recommendations for interventions and screening of cystic fibrosis patients with disordered eating: A qualitative analysis.

Chronic Illn. 2019 Oct 10;:1742395319881182

Authors: Quick V, Chang G

PMID: 31600084 [PubMed - as supplied by publisher]

S-Nitrosylation of CHIP Enhances F508Del CFTR Maturation.

Am J Respir Cell Mol Biol. 2019 Oct 09;:

Authors: Zaman K, Knight J, Hussain F, Cao R, Estabrooks SK, Altawallbeh G, Holloway K, Jafri A, Sawczak V, Li Y, Getsy P, Sun F, Raffay T, Cotton C, Brodsky JL, Periasamy A, Lewis SJ, Gaston B

Abstract
S-Nitrosothiols (SNOs) are endogenous signaling compounds with a diverse spectrum of beneficial airway effects that are both cGMP-dependent and -independent. SNOs are present in healthy human airways, but levels are low in the airways of cystic fibrosis (CF) patients. Here, we evaluated the interactions of SNOs with molecular co-chaperone C-terminus Hsc70 interacting protein (CHIP)- an E3 ubiquitin ligase that targets improperly folded CFTR for degradation. CHIP was expressed in primary human bronchial epithelial and CFBE41o - cells expressing either wild type or F508del CFTR. Confocal microscopy and immunoprecipitation studies showed the cellular co-localization of CFTR and CHIP and showed that GSNO inhibits the CHIP-CFTR interaction. SNOs significantly reduced both the expression and activity of CHIP, leading to higher levels of both the immature and mature forms of F508del CFTR; in fact, inhibition of the expression and function of CHIP by SNOs not only improved CFTR maturation, but also increased CFTR stability at the cell membrane. GSNO treated cells also had more S-nitrosylated CHIP and less ubiquitinated CFTR than untreated cells, suggesting that S-nitrosylation of CHIP prevents CFTR ubiquitination by inhibiting CHIP's E3 ubiquitin ligase function. Further, the exogenous SNOs S-nitrosoglutathione diethyl ester (GNODE) and S-nitro-N-acetylcysteine (SNOAC) increased CFTR expression at the cell surface. Following CHIP knockdown with siRNA duplexes specific for CHIP, F508del CFTR expression increased at the cell surface. We conclude that SNOs effectively reduce CHIP-mediated degradation of CFTR, resulting in increased F508del CFTR expression on the surface of airway epithelial cells.

PMID: 31596601 [PubMed - as supplied by publisher]

The Use of Ultrasound as a Tool to Evaluate Pulmonary Disease in Cystic Fibrosis.

Respir Care. 2019 Oct 08;:

Authors: Peixoto AO, Marson FA, Dertkigil SS, Dertkigil RP, Souza TH, Fraga AM, Ribeiro AF, Toro AA, Ribeiro JD

Abstract
BACKGROUND: Lung ultrasound is an examination that allows the assessment of pulmonary involvement by analyzing artifacts. Our primary aim was to correlate our lung ultrasound findings with pulmonary function and the modified Bhalla score in patients with cystic fibrosis.
METHODS: Subjects with cystic fibrosis were evaluated based on the results of lung ultrasound, pulmonary function exams (ie, spirometry before and after the use of a bronchodilator and S pO2 ), and the modified Bhalla score. The partial correlation set by age between lung ultrasound, pulmonary function, and modified Bhalla score was carried out. Lung ultrasound was graded according to a new score, ranging from 0 to 36, with a higher score being associated with a greater degree of involvement. We performed Bland-Altman and linear regression analysis to identify bias between lung ultrasound and modified Bhalla score. Alpha = 0.05.
RESULTS: 18 subjects with cystic fibrosis were included. In partial correlation controlled by age, we observed significant ultrasound score values with weight (partial correlation = -0.579), body mass index (partial correlation = -0.609), S pO2 (partial correlation = -0.728), FVC% (pre-bronchodilator: partial correlation = -0.538; post-bronchodilator: partial correlation = -0.560), FEV1% (pre-bronchodilator: partial correlation = -0.536; post-bronchodilator: partial correlation = -0.546), and modified Bhalla score (partial correlation = 0.607). We did not identify bias between lung ultrasound and modified Bhalla score measured by z-score.
CONCLUSIONS: Lung ultrasound seems to be effective and corroborates with high-resolution computed tomography when evaluated by the modified Bhalla score. At the same time, lung ultrasound had significant correlation with pulmonary function and nutritional status.

PMID: 31594833 [PubMed - as supplied by publisher]

Using digital technology for home monitoring, adherence and self-management in cystic fibrosis: a state-of-the-art review.

Thorax. 2019 Oct 08;:

Authors: Calthorpe RJ, Smith S, Gathercole K, Smyth AR

Abstract
Digital healthcare is a rapidly growing healthcare sector. Its importance has been recognised at both national and international level, with the WHO recently publishing its first global strategy for digital health. The use of digital technology within cystic fibrosis (CF) has also increased. CF is a chronic, life-limiting condition, in which the treatment burden is high and treatment regimens are not static. Digital technologies present an opportunity to support the lives of people with CF. We included 59 articles and protocols in this state-of-the-art review, relating to 48 studies from 1999 until 2019. This provides a comprehensive overview of the expansion and evolution of the use of digital technology. Technology has been used with the aim of increasing accessibility to healthcare, earlier detection of pulmonary exacerbations and objective electronic adherence monitoring. It may also be used to promote adherence and self-management through education, treatment management Apps and social media.

PMID: 31594802 [PubMed - as supplied by publisher]

GLPG2737 in lumacaftor/ivacaftor-treated CF subjects homozygous for the F508del mutation: A randomized phase 2A trial (PELICAN).

J Cyst Fibros. 2019 Oct 05;:

Authors: van Koningsbruggen-Rietschel S, Conrath K, Fischer R, Sutharsan S, Kempa A, Gleiber W, Schwarz C, Hector A, Van Osselaer N, Pano A, Corveleyn S, Bwirire D, Santermans E, Muller K, Bellaire S, Van de Steen O

Abstract
BACKGROUND: Triple combinations of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulators demonstrate enhanced clinical efficacy in CF patients with F508del mutation, compared with modest effects of dual combinations. GLPG2737 was developed as a novel corrector for triple combination therapy.
METHODS: This multicenter, randomized, double-blind, placebo-controlled, phase 2a study evaluated GLPG2737 in F508del homozygous subjects who had been receiving lumacaftor 400mg/ivacaftor 250mg for ≥12weeks. The primary outcome was change from baseline in sweat chloride concentration. Other outcomes included assessment of pulmonary function, respiratory symptoms, safety, tolerability, and pharmacokinetics.
RESULTS: Between November 2017 and April 2018, 22 subjects were enrolled and randomized to oral GLPG2737 (75mg; n=14) or placebo (n=8) capsules twice daily for 28days. A significant decrease from baseline in mean sweat chloride concentration occurred at day 28 for GLPG2737 versus placebo (least-squares-mean difference-19.6mmol/L [95% confidence interval (CI) -36.0, -3.2], p=.0210). The absolute improvement, as assessed by least-squares-mean difference in change from baseline, in forced expiratory volume in 1s (percent predicted) at day 28 for GLPG2737 versus placebo was 3.4% (95% CI -0.5, 7.3). Respiratory symptoms in both groups remained stable. Mild/moderate adverse events occurred in 10 (71.4%) and 8 (100%) subjects receiving GLPG2737 and placebo, respectively. Lower exposures of GLPG2737 (and active metabolite M4) were observed than would be expected if administered alone (as lumacaftor induces CYP3A4). Lumacaftor and ivacaftor exposures were as expected.
CONCLUSIONS: GLPG2737 was well tolerated and yielded significant decreases in sweat chloride concentration versus placebo in subjects homozygous for F508del receiving lumacaftor/ivacaftor, demonstrating evidence of increased CFTR activity when added to a potentiator-corrector combination.
FUNDING: Galapagos NV.
CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT03474042.

PMID: 31594690 [PubMed - as supplied by publisher]

Two novel and correlated CF-causing insertions in the (TG)mTn tract of the CFTR gene.

PLoS One. 2019;14(10):e0222838

Authors: Pierandrei S, Blaconà G, Fabrizzi B, Cimino G, Cirilli N, Caporelli N, Angeloni A, Cipolli M, Lucarelli M

Abstract
Two novel and related pathogenic variants of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene were structurally and functionally characterized. These alterations have not been previously described in literature. Two patients with diagnosis of Cystic Fibrosis (CF) based on the presence of one mutated allele, p.Phe508del, pathological sweat test and clinical symptoms were studied. To complete the genotypes of both patients, an extensive genetic and functional analysis of the CFTR gene was performed. Extensive genetic characterization confirmed the presence of p.Phe508del pathogenic variant and revealed, in both patients, the presence of an insertion of part of intron 10 in intron 9 of the CFTR gene, within the (TG)m repeat, with a variable poly-T stretch. The molecular lesions resulted to be very similar in both patients, with only a difference in the number of T in the poly-T stretch. The functional characterization at RNA level revealed a complete anomalous splicing, without exon 10, from the allele with the insertion of both patients. Consequently, the alleles with the insertions are expected not to contribute to the formation of a functional CFTR protein. Molecular and functional features of these alterations are compatible with the definition of novel CF-causing variants of the CFTR gene. This also allowed the completion of the genetic characterization of both patients.

PMID: 31593572 [PubMed - in process]

Secondhand Smoke Exposure and Serum Trypsinogen in Cystic Fibrosis Carriers.

Pancreas. 2019 Oct 08;:

Authors: Ellery KM, Kopp B, Conwell DL, Gariepy C

Abstract
OBJECTIVE: The objective of this study was to determine if infants carrying 1 cystic fibrosis transmembrane receptor (CFTR) mutation demonstrate pancreatic inflammation in response to tobacco exposure.
METHODS: Cystic fibrosis carrier infants aged 4 to 16 weeks were prospectively enrolled. Tobacco exposure was assessed by survey and maternal hair nicotine analysis. Serum immunoreactive trypsinogen (IRT) levels at birth and at the time of recruitment were analyzed relative to the presence or absence of tobacco exposure. The effect of the severity of the CFTR mutation carried by the infant on the tobacco-IRT relationship was also analyzed.
RESULTS: Forty-eight infants completed the study. Newborn screen and follow-up IRT levels were not different between exposed infants (19 by hair analysis) and nonexposed infants (29 by hair analysis). Follow-up IRT levels were lower in infants with more severe CFTR mutations (P = 0.005). There was no difference in follow-up IRT based on CFTR mutation severity in exposed infants. Nonexposed infants with milder CFTR mutations had higher median IRT values on follow-up testing than those with more severe CFTR mutations (P < 0.05).
CONCLUSIONS: The pancreas of cystic fibrosis carrier infants is affected by tobacco exposure, and those carrying less severe CFTR mutations may be more susceptible to tobacco effects.

PMID: 31593019 [PubMed - as supplied by publisher]

Restless Legs Syndrome in Chronic Kidney Disease: Is Iron or Inflammatory Status To Blame?

J Clin Sleep Med. 2019 Oct 08;:

Authors: Riar SK, Greenbaum LA, Bliwise DL, Leu RM

Abstract
STUDY OBJECTIVES: Restless legs syndrome (RLS) is increased in pediatric chronic kidney disease (CKD). In adults without CKD, central nervous system iron deficiency is involved in RLS pathogenesis and a low serum ferritin levels is consequently an indication for initiation of iron therapy. However, children with CKD are at risk for iron deficiency and inflammation, which raises serum ferritin. We examined the role of iron deficiency and inflammation in RLS in pediatric CKD.
METHODS: This cross-sectional study examined RLS prevalence in three groups of pediatric patients with CKD: nontransplant, nondialysis CKD (estimated GFR < 60 mL/min/1.73 m²) (n = 27); renal transplant recipients (n = 65); and dialysis (n = 32). RLS was diagnosed using a validated questionnaire. Serum ferritin < 100 ng/mL or transferrin saturation < 20% defined iron deficiency. Serum high sensitivity C-reactive protein ≥ 1 mg/L defined inflammation.
RESULTS: Among 124 patients, RLS prevalence was 15.3%; this did not differ across groups. There was no significant difference in RLS prevalence between those with and without iron deficiency, defined by either reduced ferritin or transferrin. Median ferritin levels in patients with RLS tended to be higher than in those without RLS (51.2 versus 40.1 ng/mL; P = .08). Inflammation (elevated CRP) also did not differ significantly by RLS status (57.9% [with RLS] versus 41.2% [without RLS], P = .18).
CONCLUSIONS: Neither ferritin nor inflammation differentiated pediatric patients with CKD with and without RLS. This study suggests that the factors mediating the pathogenesis and, potentially, treatment, of RLS in pediatric CKD may be different from non-CKD populations.

PMID: 31591957 [PubMed - as supplied by publisher]

Anaphylaxis and anaphylactoid reactions associated with the insertion of peripherally inserted central catheters: A multiyear comparative retrospective cohort study.

Infect Control Hosp Epidemiol. 2019 Oct 08;:1-7

Authors: Thornton CS, Dumanski J, Margherit C, Vaz-Gonsalves S, McDiarmid S, Parkins MD, Conly JM

Abstract
OBJECTIVE: Peripherally inserted central catheters (PICCs) are a mainstay of nonpermanent vascular access devices. In this study, we assessed patients displaying anaphylaxis or anaphylactoid reactions to the PowerPICC SOLO and Groshong PICC (Bard Access Systems) using the Sherlock tip locating system (TLS).
METHODS: Patients from 2 tertiary-care hospitals were systematically monitored over 4 years for adverse events following the insertion of a PICC using the Sherlock TLS. Insertion data were also collected using the BioFlo PICC (Angiodynamics)from a third hospital site and from The Ottawa Hospital over 4 years as an additional comparator. Three definitions of anaphylaxis and anaphylactoid reactions were utilized, and the Cohen κ was used to assess interrater agreement. Analysis of reactions among the patient cohorts was performed using the χ2 test with Yates correction or the Fisher exact test as appropriate.
RESULTS: Among 8,257 insertions using the TLS PICCs, 37 potential reactions (0.45%) were recorded. Using specific definitions for anaphylaxis or anaphylactoid reactions, 54.1%-91.9% met criteria. Comparator populations using data from Calgary (n = 491) and Ottawa (n = 7,889) using the BioFlo PICC insertion found no reactions. Anaphylactic or anaphylactoid reactions were significantly associated with the PowerPICC SOLO and Groshong PICC with the TLS compared to the BioFlo PICC (P < .0001) across all definitions. The largest subset of patients experiencing adverse reactions had cystic fibrosis (CF) (n = 4, 10.8%).
CONCLUSION: Our study results demonstrate significant adverse events associated with the PowerPICC SOLO and Groshong PICC using the Sherlock TLS inserted across a range of patient populations. The incidence rate of anaphylaxis or anaphylactoid reactions in the CF population at our center is significantly higher than in non-CF patients (P < .001).

PMID: 31591954 [PubMed - as supplied by publisher]

A novel high-throughput molecular counting method with single base-pair resolution enables accurate single-gene NIPT.

Sci Rep. 2019 Oct 07;9(1):14382

Authors: Tsao DS, Silas S, Landry BP, Itzep NP, Nguyen AB, Greenberg S, Kanne CK, Sheehan VA, Sharma R, Shukla R, Arora PN, Atay O

Abstract
Next-generation DNA sequencing is currently limited by an inability to accurately count the number of input DNA molecules. Molecular counting is particularly needed when accurate quantification is required for diagnostic purposes, such as in single gene non-invasive prenatal testing (sgNIPT) and liquid biopsy. We developed Quantitative Counting Template (QCT) molecular counting to reconstruct the number of input DNA molecules using sequencing data. We then used QCT molecular counting to develop sgNIPTs of sickle cell disease, cystic fibrosis, spinal muscular atrophy, alpha-thalassemia, and beta-thalassemia. The analytical sensitivity and specificity of sgNIPT was >98% and >99%, respectively. Validation of sgNIPTs was further performed with maternal blood samples collected during pregnancy, and sgNIPTs were 100% concordant with newborn follow-up.

PMID: 31591409 [PubMed - in process]

Transforming Growth Factor-β1 Selectively Recruits microRNAs to the RNA-Induced Silencing Complex and Degrades CFTR mRNA under Permissive Conditions in Human Bronchial Epithelial Cells.

Int J Mol Sci. 2019 Oct 05;20(19):

Authors: Mitash N, Mu F, Donovan JE, Myerburg MM, Ranganathan S, Greene CM, Swiatecka-Urban A

Abstract
<p>Mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (<italic>CFTR</italic>) gene lead to cystic fibrosis (CF). The most common mutation F508del inhibits folding and processing of CFTR protein. FDA-approved correctors rescue the biosynthetic processing of F508del-CFTR protein, while potentiators improve the rescued CFTR channel function. Transforming growth factor (TGF-β1), overexpressed in many CF patients, blocks corrector/potentiator rescue by inhibiting CFTR mRNA in vitro. Increased TGF-β1 signaling and acquired CFTR dysfunction are present in other lung diseases. To study the mechanism of TGF-β1 repression of CFTR, we used molecular, biochemical, and functional approaches in primary human bronchial epithelial cells from over 50 donors. TGF-β1 destabilized CFTR mRNA in cells from lungs with chronic disease, including CF, and impaired F508del-CFTR rescue by new-generation correctors. TGF-β1 increased the active pool of selected micro(mi)RNAs validated as CFTR inhibitors, recruiting them to the RNA-induced silencing complex (RISC). Expression of F508del-CFTR globally modulated TGF-β1-induced changes in the miRNA landscape, creating a permissive environment required for degradation of F508del-CFTR mRNA. In conclusion, TGF-β1 may impede the full benefit of corrector/potentiator therapy in CF patients. Studying miRNA recruitment to RISC under disease-specific conditions may help to better characterize the miRNAs utilized by TGF-β1 to destabilize CFTR mRNA.

PMID: 31590401 [PubMed - in process]

Prevalence and characterization of chronic rhinosinusitis in patients with non-cystic fibrosis bronchiectasis at a tertiary care center in the United States.

Int Forum Allergy Rhinol. 2019 Oct 07;:

Authors: Somani SN, Kwah JH, Yeh C, Conley DB, Grammer LC, Kern RC, Prickett M, Schleimer RP, Smith SS, Stevens WW, Tan BK, Welch KC, Peters AT

Abstract
BACKGROUND: Chronic rhinosinusitis (CRS) is associated with bronchiectasis; however, this relationship has not been well studied in the United States (US) population. In this work we aimed to determine the prevalence of CRS among patients with bronchiectasis affiliated with a US tertiary medical center and identify which comorbid diseases are associated with the presence of CRS in patients with bronchiectasis.
METHODS: This was a retrospective cohort study in which data were obtained from a large database warehouse at a tertiary care center. Patients with bronchiectasis were identified from 2007 to 2017 using diagnosis codes from the the ninth and tenth revisions of the International Classification of Diseases (ICD-9/10) and confirmed by radiographic evidence of bronchiectasis on chest computed tomography (CT) scans. Patients were divided into cohorts based on presence or absence of concomitant CRS. Characteristics analyzed included demographics, comorbidities, peripheral eosinophil counts, and pulmonary function testing.
RESULTS: CRS was present in 45% (408 of 900) of patients with bronchiectasis. Females represented a majority of bronchiectasis patients, both with and without CRS (69% and 64%, respectively, p = 0.09). After controlling for demographic factors, asthma (p < 0.01), allergic rhinitis (p < 0.01), gastroesophageal reflux disease (p < 0.01), and antibody deficiency (p < 0.01) were associated with the presence of CRS in patients with bronchiectasis.
CONCLUSION: CRS had a high prevalence and was associated with numerous comorbid conditions in patients with bronchiectasis. These findings have clinical implications for the treatment of patients with bronchiectasis and future research.

PMID: 31589811 [PubMed - as supplied by publisher]

Lung transplantation: a review of the optimal strategies for referral and patient selection.

Ther Adv Respir Dis. 2019 Jan-Dec;13:1753466619880078

Authors: Mitchell AB, Glanville AR

Abstract
One of the great challenges of lung transplantation is to bridge the dichotomy between supply and demand of donor organs so that the maximum number of potential recipients achieve a meaningful benefit in improvements in survival and quality of life. To achieve this laudable goal is predicated on choosing candidates who are sufficiently unwell, in fact possessing a terminal respiratory illness, but otherwise fit and able to undergo major surgery and a prolonged recuperation and rehabilitation stage combined with ongoing adherence to complex medical therapies. The choice of potential candidate and the timing of that referral is at times perhaps more art than science, but there are a number of solid guidelines for specific illnesses to assist the interested clinician. In this regard, the relationship between the referring clinician and the lung transplant unit is a critical one. It is an ongoing and dynamic process of education and two way communication, which is a marker of the professionalism of a highly performing unit. Lung transplantation is ultimately a team effort where the recipient is the key player. That principle has been enshrined in the three consensus position statements regarding selection criteria for lung and heart-lung transplantation promulgated by the International Society for Heart and Lung Transplantation over the last two decades. During this period, the number of indications for lung transplantation have broadened and the number of contraindications reduced. Risk management is paramount in the pre- and perioperative period to effect early successful outcomes. While it is not the province of this review to reiterate the detailed listing of those factors, an overview position will be developed that describes the rationale and evidence for selected criteria where that exists. Importantly, the authors will attempt to provide an historical and experiential basis for making these important and life-determining decisions. The reviews of this paper are available via the supplementary material section.

PMID: 31588850 [PubMed - in process]

Antibiotics for treating osteomyelitis in people with sickle cell disease.

Cochrane Database Syst Rev. 2019 Oct 07;10:CD007175

Authors: Martí-Carvajal AJ, Agreda-Pérez LH

Abstract
BACKGROUND: Osteomyelitis (both acute and chronic) is one of the most common infectious complications in people with sickle cell disease. There is no standardized approach to antibiotic therapy and treatment is likely to vary from country to country. Thus, there is a need to identify the efficacy and safety of different antibiotic treatment approaches for people with sickle cell disease suffering from osteomyelitis. This is an update of a previously published Cochrane Review.
OBJECTIVES: To determine whether an empirical antibiotic treatment approach (monotherapy or combination therapy) is effective and safe as compared to pathogen-directed antibiotic treatment and whether this effectiveness and safety is dependent on different treatment regimens, age or setting.
SEARCH METHODS: We searched The Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the LILACS database (1982 to 20 October 2016), African Index Medicus (20 October 2016), ISI Web of Knowledge (20 October 2016) and clinical trials registries (19 September 2019).Date of most recent search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 18 September 2019.
SELECTION CRITERIA: We searched for published or unpublished randomised and quasi-randomised controlled trials.
DATA COLLECTION AND ANALYSIS: Each author intended to independently extract data and assess trial quality by standard Cochrane methodologies, but no eligible randomised controlled trials were identified.
MAIN RESULTS: This update was unable to find any randomised or quasi-randomised controlled trials on antibiotic treatment approaches for osteomyelitis in people with sickle cell disease.
AUTHORS' CONCLUSIONS: We were unable to identify any relevant trials on the efficacy and safety of the antibiotic treatment approaches for people with sickle cell disease suffering from osteomyelitis. Randomised controlled trials are needed to establish the optimum antibiotic treatment for this condition, however, we do not envisage further trials of this intervention will be conducted, and hence the review will no longer be regularly updated.

PMID: 31588556 [PubMed - as supplied by publisher]

Bilateral Severe Decreased Vision With Normal Examination Findings.

JAMA Ophthalmol. 2018 10 01;136(10):1201-1202

Authors: Rayess N, Patel VR

PMID: 30073263 [PubMed - indexed for MEDLINE]

Amyloidosis as a Cause of Cystic Pulmonary Fibrosis Associated With Pulmonary Nodules.

Arch Bronconeumol. 2018 09;54(9):481-482

Authors: García-Sánchez A, Villasante C, Esteban-Rodriguez I, García-Río F F

PMID: 29656944 [PubMed - indexed for MEDLINE]

Inhalational Anesthetics Induce Neuronal Protein Aggregation and Affect ER Trafficking.

Sci Rep. 2018 03 27;8(1):5275

Authors: Coghlan M, Richards E, Shaik S, Rossi P, Vanama RB, Ahmadi S, Petroz C, Crawford M, Maynes JT

Abstract
Anesthetic agents have been implicated in the causation of neurological and cognitive deficits after surgery, the exacerbation of chronic neurodegenerative disease, and were recently reported to promote the onset of the neurologic respiratory disease Congenital Central Hypoventilation Syndrome (CCHS), related to misfolding of the transcription factor Phox2B. To study how anesthetic agents could affect neuronal function through alterations to protein folding, we created neuronal cell models emulating the graded disease severity of CCHS. We found that the gas anesthetic isoflurane and the opiate morphine potentiated aggregation and mislocalization of Phox2B variants, similar to that seen in CCHS, and observed transcript and protein level changes consistent with activation of the endoplasmic reticulum (ER) unfolded protein response. Attenuation of ER stress pathways did not result in a correction of Phox2B misfolding, indicating a primary effect of isoflurane on protein structure. We also observed that isoflurane hindered the folding and activity of proteins that rely heavily on ER function, like the CFTR channel. Our results show how anesthetic drugs can alter protein folding and induce ER stress, indicating a mechanism by which these agents may affect neuronal function after surgery.

PMID: 29588456 [PubMed - indexed for MEDLINE]

Impact of early caffeine therapy in preterm newborns on infant lung function.

Pediatr Pulmonol. 2019 Oct 06;:

Authors: Sanchez-Solis M, Garcia-Marcos PW, Agüera-Arenas J, Mondejar-Lopez P, Garcia-Marcos L

Abstract
OBJECTIVE: To know the effect of caffeine therapy on infant lung function in preterm infants with a gestational age less than 31 weeks.
MATERIAL AND METHODS: Forced vital capacity (FVC), forced expiratory volume at 0.5 seconds (FEV0.5 ), and forced expiratory flows were measured by raised volume rapid thoracoabdominal compression technique; functional residual capacity was measured by plethysmography (FRCpleth ). Compliance of the respiratory system was measured by a single interruption technique (Crs). The Student t test was used to compare lung function measurements between the two groups: treated versus nontreated with caffeine. A multivariate analysis was carried out considering each and every lung function parameter (z-score) as the dependent variable; and gender, gestational age, birth weight (z-score), corrected age, invasive mechanical ventilation (yes/no), and bronchopulmonary dysplasia (BPD) diagnosis (yes/no) as independent ones. Additionally, stratified analyses by BPD diagnosis were performed.
RESULTS: The multivariate analysis showed significant higher z-scores of FVC and FEV0.5 in preterm infants treated with caffeine (P = .004 and P = .024, respectively). This result only being significant in the group of non-BPD infants (P = .021 and P = .042), after stratifying by BPD diagnosis. Differences were not found in z-scores of FEV0.5/FVC, FEF75, FEF25-75, FRCpleth, nor Crs.
CONCLUSION: Lung function (FVC and FEV0.5 ) is improved in infants born under 31 weeks of gestation when treated with caffeine. This improvement is driven by the group of infants who did not suffer from BPD. Overall, our results show that there is an early beneficial effect of caffeine treatment in infant lung function.

PMID: 31587528 [PubMed - as supplied by publisher]

Positional effects of premature termination codons on the biochemical and biophysical properties of CFTR.

J Physiol. 2019 Oct 04;:

Authors: Yeh JT, Hwang TC

Abstract
KEY POINTS: Biochemical and biophysical characterizations of three nonsense mutations of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) associated with severe form of cystic fibrosis (CF) reveal the importance and heterogenous effects of the position of the premature termination codon (PTC) on the CFTR protein function. Electrophysiological studies of W1282X-CFTR, whose PTC is closer to the C-terminus of CFTR, suggest the presence of both C-terminus truncated CFTR proteins that are poorly functional and read-through, full-length products. For G542X- and E60X-CFTR, the only mechanism capable of generating functional proteins is the read-through, but the outcome of read-through products is highly variable depending on the interplay between the missense mutation caused by the read-through and the structural context of the protein. Pharmacological studies of these three PTCs with various CFTR modulators suggest position-dependent therapeutic strategies for these disease-inflicting mutations.
ABSTRACT: About one-third of genetic diseases and cancers are caused by the introduction of premature termination codon (PTC). In theory, the location of the PTC in a gene determines the alternative mechanisms of translation, including premature cessation or reinitiation of translation, and read-through, resulting in differential effects on protein integrity. In this study, we used CFTR as a model system to investigate the positional effect of the PTC because of its well-understood structure-function relationship and pathophysiology. The characterization of three PTC mutations, E60X-, G542X- and W1282X-CFTR revealed heterogenous effects of these PTCs on CFTR function. The W1282X mutation results in both C-terminus truncated and read-through proteins that are partially or fully functional. In contrast, only the read-through protein is functional with E60X- and G542X-CFTR, although abundant N-terminus truncated proteins due to reinitiation of translation were detected in E60X-CFTR. Single-channel studies of the read-through proteins of E60X- and G542X-CFTR demonstrated that both mutations have a similar single-channel amplitude as WT, and good responses to high-affinity ATP-analogue, suggesting intact ion permeation pathways and NBDs, albeit with reduced open probability (Po). The comparison of the Po of these mutations with the proposed missense mutations revealed potential identities of the read-through products. Importantly, a majority of the functional protein studied responds to CFTR modulators like GLPG1837 and Lumacaftor. These results not only expand current understanding of the molecular (patho)physiology of CFTR, but also infer therapeutic strategies for different PTC mutations at large. This article is protected by copyright. All rights reserved.

PMID: 31585024 [PubMed - as supplied by publisher]