Real-time in vivo imaging of regional lung function in a mouse model of cystic fibrosis on a laboratory X-ray source.

Sci Rep. 2020 Jan 16;10(1):447

Authors: Murrie RP, Werdiger F, Donnelley M, Lin YW, Carnibella RP, Samarage CR, Pinar I, Preissner M, Wang J, Li J, Morgan KS, Parsons DW, Dubsky S, Fouras A

Abstract
Most measures of lung health independently characterise either global lung function or regional lung structure. The ability to measure airflow and lung function regionally would provide a more specific and physiologically focused means by which to assess and track lung disease in both pre-clinical and clinical settings. One approach for achieving regional lung function measurement is via phase contrast X-ray imaging (PCXI), which has been shown to provide highly sensitive, high-resolution images of the lungs and airways in small animals. The detailed images provided by PCXI allow the application of four-dimensional X-ray velocimetry (4DxV) to track lung tissue motion and provide quantitative information on regional lung function. However, until recently synchrotron facilities were required to produce the highly coherent, high-flux X-rays that are required to achieve lung PCXI at a high enough frame rate to capture lung motion. This paper presents the first translation of 4DxV technology from a synchrotron facility into a laboratory setting by using a liquid-metal jet microfocus X-ray source. This source can provide the coherence required for PCXI and enough X-ray flux to image the dynamics of lung tissue motion during the respiratory cycle, which enables production of images compatible with 4DxV analysis. We demonstrate the measurements that can be captured in vivo in live mice using this technique, including regional airflow and tissue expansion. These measurements can inform physiological and biomedical research studies in small animals and assist in the development of new respiratory treatments.

PMID: 31949224 [PubMed - in process]

Early Markers of Cystic Fibrosis Structural Lung Disease: Follow-Up of the ACFBAL Cohort.

Eur Respir J. 2020 Jan 16;:

Authors: Wijker NE, Vidmar S, Grimwood K, Sly PD, Byrnes CA, Carlin JB, Cooper PJ, Robertson CF, Massie RJ, Kemner van de Corput MPC, Cheney J, Tiddens HAWM, Wainwright CE, Australasian Cystic Fibrosis Bronchoalveolar Lavage (ACFBAL) and Follow-up of the ACFBAL (CF-FAB) study groups

Abstract
INTRODUCTION: Little is known about early predictors of later cystic fibrosis (CF) structural lung disease. This study examined early predictors of progressive structural lung abnormalities in children who completed the Australasian CF Bronchoalveolar Lavage (ACFBAL) clinical trial at age 5-years and participated in an observational follow-up study (CF-FAB).
METHODS: Eight Australian and New Zealand CF centres participated in CF-FAB and provided follow-up chest computed-tomography (CT) scans for children who had completed the ACFBAL study with baseline scans at age 5-years. CT-scans were annotated using PRAGMA-CF scoring. Ordinal regression analysis and linear regression were used to investigate associations between PRAGMA-CF outcomes at follow-up and variables measured during the ACFBAL study.
RESULTS: Ninety-nine of 157 ACFBAL children (mean age 13-years, standard deviation 1.5) participated in the CF-FAB study. The probability of bronchiectasis at follow-up increased with airway disease severity on the baseline CT-scan. In multiple regression (retaining factors at p<0.05) the extent of bronchiectasis at follow-up was associated with baseline atelectasis (odds ratio (OR)7.2; 95% confidence interval (CI) 2.4, 22; P≤ 0.001), bronchoalveolar lavage (BAL) log2 interleukin (IL)-8 (OR 1.2 95%CI 1.05, 1.5; p=0.010) and body mass index z-score (OR 0.49, 95%CI 0.24, 1.00; p=0.05) at age 5-years. Percent trapped air at follow-up was associated with BAL log2 IL-8 (coefficient 1.3, 95%CI 0.57, 2.1; p<0.001) at age 5-years.
CONCLUSIONS: The extent of airway disease, atelectasis, airway inflammation, and poor nutritional status in early childhood are risk-factors for progressive structural lung disease in adolescence.

PMID: 31949117 [PubMed - as supplied by publisher]

New approaches to genetic therapies for cystic fibrosis.

J Cyst Fibros. 2020 Jan 13;:

Authors: Christopher Boyd A, Guo S, Huang L, Kerem B, Oren YS, Walker AJ, Hart SL

Abstract
Gene therapy offers great promise for cystic fibrosis which has never been quite fulfilled due to the challenges of delivering sufficient amounts of the CFTR gene and expression persistence for a sufficient period of time in the lungs to have any effect. Initial trials explored both viral and non-viral vectors but failed to achieve a significant breakthrough. However, in recent years, new opportunities have emerged that exploit our increased knowledge and understanding of the biology of CF and the airway epithelium. New technologies include new viral and non-viral vector approaches to delivery, but also alternative nucleic acid technologies including oligonucleotides and siRNA approaches for gene silencing and gene splicing, described in this review, as presented at the 2019 annual European CF Society Basic Science meeting (Dubrovnik, Croatia). We also briefly discuss other emerging technologies including mRNA and CRISPR gene editing that are advancing rapidly. The future prospects for genetic therapies for CF are now diverse and more promising probably than any time since the discovery of the CF gene.

PMID: 31948871 [PubMed - as supplied by publisher]

Prevalence and incidence of bronchiectasis in Italy.

BMC Pulm Med. 2020 Jan 16;20(1):15

Authors: Aliberti S, Sotgiu G, Lapi F, Gramegna A, Cricelli C, Blasi F

Abstract
BACKGROUND: The understanding of the epidemiology of bronchiectasis is still affected by major limitations with very few data published worldwide. The aim of this study was to estimate the epidemiological burden of bronchiectasis in Italy in the adult population followed-up by primary care physicians.
METHODS: This study analyzed data coming from a large primary care database with 1,054,376 subjects in the period of time 2002-2015. Patients with bronchiectasis were selected by the use of International Statistical Classification of Diseases, 9th revision, Clinical Modification codes (ICD-9-CM).
RESULTS: Patients with bronchiectasis were more likely to have a history of tuberculosis (0.47% vs. 0.06%, p < 0.0001), had higher rates of asthma (16.6% vs. 6.2%, p < 0.0001), COPD (23.3% vs. 6.4%, p < 0.0001) and rheumatoid arthritis (1.9% vs. 0.8%, p < 0.0001). The prevalence and incidence of bronchiectasis in primary care in Italy in 2015 were 163 per 100,000 population and 16.3 per 100,000 person-years, respectively. Prevalence and incidence increased with age and overall rates were highest in men over 75 years old. Prevalence and incidence computed after the exclusion of patients with a diagnosis of either asthma or COPD is 130 per 100,000 and 11.1 cases per 100,000 person-years, respectively.
CONCLUSIONS: Bronchiectasis is not a rare condition in Italian adult population. Further studies are needed to confirm our results and provide a better insight on etiology of bronchiectasis in Italy.
TRIAL REGISTRATION: not applicable.

PMID: 31948411 [PubMed - in process]

The Fundamental Role of Bicarbonate Transporters and Associated Carbonic Anhydrase Enzymes in Maintaining Ion and pH Homeostasis in Non-Secretory Organs.

Int J Mol Sci. 2020 Jan 04;21(1):

Authors: Lee D, Hong JH

Abstract
The bicarbonate ion has a fundamental role in vital systems. Impaired bicarbonate transport leads to various diseases, including immune disorders, cystic fibrosis, tumorigenesis, kidney diseases, brain dysfunction, tooth fracture, ischemic reperfusion injury, hypertension, impaired reproductive system, and systemic acidosis. Carbonic anhydrases are involved in the mechanism of bicarbonate movement and consist of complex of bicarbonate transport systems including bicarbonate transporters. This review focused on the convergent regulation of ion homeostasis through various ion transporters including bicarbonate transporters, their regulatory enzymes, such as carbonic anhydrases, pH regulatory role, and the expression pattern of ion transporters in non-secretory systems throughout the body. Understanding the correlation between these systems will be helpful in order to obtain new insights and design potential therapeutic strategies for the treatment of pH-related disorders. In this review, we have discussed the broad prospects and challenges that remain in elucidation of bicarbonate-transport-related biological and developmental systems.

PMID: 31947992 [PubMed - in process]

Blood transfusions for treating acute chest syndrome in people with sickle cell disease.

Cochrane Database Syst Rev. 2020 Jan 16;1:CD007843

Authors: Dolatkhah R, Dastgiri S

Abstract
BACKGROUND: Sickle cell disease is an inherited autosomal recessive blood condition and is one of the most prevalent genetic blood diseases worldwide. Acute chest syndrome is a frequent complication of sickle cell disease, as well as a major cause of morbidity and the greatest single cause of mortality in children with sickle cell disease. Standard treatment may include intravenous hydration, oxygen as treatment for hypoxia, antibiotics to treat the infectious cause and blood transfusions may be given. This is an update of a Cochrane Review first published in 2010 and updated in 2016.
OBJECTIVES: To assess the effectiveness of blood transfusions, simple and exchange, for treating acute chest syndrome by comparing improvement in symptoms and clinical outcomes against standard care.
SEARCH METHODS: We searched The Cochrane Cystic Fibrosis and Genetic Disorders 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. Date of the most recent search: 30 May 2019.
SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials comparing either simple or exchange transfusion versus standard care (no transfusion) in people with sickle cell disease suffering from acute chest syndrome.
DATA COLLECTION AND ANALYSIS: Both authors independently selected trials and assessed the risk of bias, no data could be extracted.
MAIN RESULTS: One trial was eligible for inclusion in the review. While in the multicentre trial 237 people were enrolled (169 SCC, 42 SC, 15 Sβ⁰-thalassaemia, 11Sβ+-thalassaemia); the majority were recruited to an observational arm and only ten participants met the inclusion criteria for randomisation. Of these, four were randomised to the transfusion arm and received a single transfusion of 7 to 13 mL/kg packed red blood cells, and six were randomised to standard care. None of the four participants who received packed red blood cells developed acute chest syndrome, while 33% (two participants) developed acute chest syndrome in standard care arm. No data for any pre-defined outcomes were available.
AUTHORS' CONCLUSIONS: We found only one very small randomised controlled trial; this is not enough to make any reliable conclusion to support the use of blood transfusion. Whilst there appears to be some indication that chronic blood transfusion may play a roll in reducing the incidence of acute chest syndrome in people with sickle cell disease and albeit offering transfusions may be a widely accepted clinical practice, there is currently no reliable evidence to support or refute the perceived benefits of these as treatment options; very limited information about any of the potential harms associated with these interventions or indeed guidance that can be used to aid clinical decision making. Clinicians should therefore base any treatment decisions on a combination of; their clinical experience, individual circumstances and the unique characteristics and preferences of adequately informed people with sickle cell disease who are suffering with acute chest syndrome. This review highlights the need of further high quality research to provide reliable evidence for the effectiveness of these interventions for the relief of the symptoms of acute chest syndrome in people with sickle cell disease.

PMID: 31942751 [PubMed - in process]

Characterization of two rat models of cystic fibrosis-KO and F508del CFTR-Generated by Crispr-Cas9.

Animal Model Exp Med. 2019 Dec;2(4):297-311

Authors: Dreano E, Bacchetta M, Simonin J, Galmiche L, Usal C, Slimani L, Sadoine J, Tesson L, Anegon I, Concordet JP, Hatton A, Vignaud L, Tondelier D, Sermet-Gaudelus I, Chanson M, Cottart CH

Abstract
Background: Genetically engineered animals are essential for gaining a proper understanding of the disease mechanisms of cystic fibrosis (CF). The rat is a relevant laboratory model for CF because of its zootechnical capacity, size, and airway characteristics, including the presence of submucosal glands.
Methods: We describe the generation of a CF rat model (F508del) homozygous for the p.Phe508del mutation in the transmembrane conductance regulator (Cftr) gene. This model was compared to new Cftr -/- rats (CFTR KO). Target organs in CF were examined by histological staining of tissue sections and tooth enamel was quantified by micro-computed tomography. The activity of CFTR was evaluated by nasal potential difference (NPD) and short-circuit current measurements. The effect of VX-809 and VX-770 was analyzed on nasal epithelial primary cell cultures from F508del rats.
Results: Both newborn F508del and Knock out (KO) animals developed intestinal obstruction that could be partly compensated by special diet combined with an osmotic laxative. The two rat models exhibited CF phenotypic anomalies such as vas deferens agenesis and tooth enamel defects. Histology of the intestine, pancreas, liver, and lungs was normal. Absence of CFTR function in KO rats was confirmed ex vivo by short-circuit current measurements on colon mucosae and in vivo by NPD, whereas residual CFTR activity was observed in F508del rats. Exposure of F508del CFTR nasal primary cultures to a combination of VX-809 and VX-770 improved CFTR-mediated Cl- transport.
Conclusions: The F508del rats reproduce the phenotypes observed in CFTR KO animals and represent a novel resource to advance the development of CF therapeutics.

PMID: 31942562 [PubMed]

Adolescents with chronic disease and social media: a cross-sectional study.

Arch Dis Child. 2020 Jan 15;:

Authors: De Nardi L, Trombetta A, Ghirardo S, Genovese MRL, Barbi E, Taucar V

Abstract
OBJECTIVE: This study aims to explore the attitude of adolescents with chronic diseases toward social media exposure, focusing in particular on Facebook.
DESIGN: Cross-sectional study.
SETTING: An anonymous semistructured survey was distributed to an Italian hospital-based cohort of adolescents with chronic disease to explore the role of Facebook in their daily life.
PATIENTS: We recruited 212 adolescents (aged between 13 and 24 years) with a diagnosis of inflammatory bowel disease, coeliac disease, diabetes mellitus type 1 and cystic fibrosis.
RESULTS: Two hundred and seven of the 212 (97.6%) expressed the need of sharing their illness experience with friends, 201 out of 212 (94.8%) usually searched information on the internet to find new therapies and to discover their prognosis. One hundred and forty-nine out of 212 adolescents (70.3%) perceived dependence on their parents as the most negative aspect of having a chronic disease, and 200 out of 212 (94.3%) were looking for friends with the same disease on Facebook. Two hundred and ten out of 212 (99.1%) did not want their doctors or nurse on their social media platforms. During the active disease periods, the time spent with social media increased from an average of 5 to 11 hours.
CONCLUSIONS: This descriptive analysis focused on the Facebook impact on chronic disease perception among affected adolescents. It showed that they used to spend an increased amount of time on this platform during disease flare-up and highlighted their wish of keeping doctors and nurses away from their social dimension.

PMID: 31941715 [PubMed - as supplied by publisher]

Pancreatitis in A Patient with Cystic Fibrosis Taking Ivacaftor.

Children (Basel). 2020 Jan 12;7(1):

Authors: Petrocheilou A, Kaditis AG, Loukou I

Abstract
Pancreatitis is rare in pancreatic insufficient cystic fibrosis patients. While pancreatic insufficiency has been considered irreversible until now, in the current era of new therapies with modulators of the Cystic Fibrosis Transmembrane Regulator CFTR channel, there are reports of improvement of pancreatic exocrine function. We describe the case of an adolescent with cystic fibrosis who developed pancreatitis after the partial recovery of pancreatic function while taking ivacaftor. This case adds to the limited body of evidence that CFTR modulators lead to the improvement of pancreatic exocrine function in cystic fibrosis.

PMID: 31940891 [PubMed]

The Cystic Fibrosis Transmembrane Conductance Regulator 470 Met Allele Is Associated with an Increased Risk of Chronic Pancreatitis in Both Asian and Caucasian Populations: A Meta-Analysis.

Genet Test Mol Biomarkers. 2020 Jan;24(1):24-32

Authors: Zhou D, Bai R, Wang L

Abstract
Background: The Met470Val polymorphism (1540A>G [rs213950]) within the cystic fibrosis transmembrane conductance regulator (CFTR) protein has been reported to be associated with chronic pancreatitis (CP). The results remain inconclusive, and therefore, we performed this meta-analysis to clarify the association between M470V and CP risk. Methodology/Results: We conducted a meta-analysis of 7 case-control studies, including a total of 1121 CP patients and 2209 controls from Asian and Caucasian populations. We calculated the odds ratio (OR) and 95% confidence intervals (95% CI). Met470Val was found to be significantly associated with an increased risk of CP under all the genetic models (M vs. V, OR = 1.260, 95% CI: 1.134-1.399; MV vs. VV, OR = 1.292, 95% CI: 1.091-1.530; MM vs. VV, OR = 1.579, 95% CI: 1.274-1.956; MV/MV vs. VV, OR = 1.366, 95% CI: 1.165-1.603; MM vs. MV/VV, OR = 1.346, 95% CI: 1.114-1.621). Met470Val was also found to be significantly associated with an increased risk of idiopathic CP (ICP) in allele contrast, codominant, and recessive models (M vs. V, OR = 1.298, 95% CI: 1.020-1.653; MV vs. VV, OR = 1.297, 95% CI: 1.074-1.566; MM vs. VV, OR = 1.473, 95% CI: 1.165-1.862; MM vs. MV/VV, OR = 1.254, 95% CI: 1.023-1.538). Conclusions: The CFTR 470 M allele is significantly associated with an increased risk of CP in both Asian and Caucasian populations. The CFTR 470 M allele is also significantly associated with risk of ICP.

PMID: 31940241 [PubMed - in process]

Quantitative Framework for Model Evaluation in Microbiology Research Using Pseudomonas aeruginosa and Cystic Fibrosis Infection as a Test Case.

mBio. 2020 Jan 14;11(1):

Authors: Cornforth DM, Diggle FL, Melvin JA, Bomberger JM, Whiteley M

Abstract
Laboratory models are a cornerstone of modern microbiology, but the accuracy of these models has not been systematically evaluated. As a result, researchers often choose models based on intuition or incomplete data. We propose a general quantitative framework to assess model accuracy from RNA sequencing data and use this framework to evaluate models of Pseudomonas aeruginosa cystic fibrosis (CF) lung infection. We found that an in vitro synthetic CF sputum medium model and a CF airway epithelial cell model had the highest genome-wide accuracy but underperformed on distinct functional categories, including porins and polyamine biosynthesis for the synthetic sputum medium and protein synthesis for the epithelial cell model. We identified 211 "elusive" genes that were not mimicked in a reference strain grown in any laboratory model but found that many were captured by using a clinical isolate. These methods provide researchers with an evidence-based foundation to select and improve laboratory models.IMPORTANCE Laboratory models have become a cornerstone of modern microbiology. However, the accuracy of even the most commonly used models has never been evaluated. Here, we propose a quantitative framework based on gene expression data to evaluate model performance and apply it to models of Pseudomonas aeruginosa cystic fibrosis lung infection. We discovered that these models captured different aspects of P. aeruginosa infection physiology, and we identify which functional categories are and are not captured by each model. These methods will provide researchers with a solid basis to choose among laboratory models depending on the scientific question of interest and will help improve existing experimental models.

PMID: 31937646 [PubMed - in process]

Lessons From Continuous Glucose Monitoring in Youth With Pre-Type 1 Diabetes, Obesity, and Cystic Fibrosis.

Diabetes Care. 2020 Jan 14;:

Authors: Chan CL, Steck AK, Severn C, Pyle L, Rewers M, Zeitler PS

PMID: 31937609 [PubMed - as supplied by publisher]

Regulation of CFTR Biogenesis by the Proteostatic Network and Pharmacological Modulators.

Int J Mol Sci. 2020 Jan 10;21(2):

Authors: Estabrooks S, Brodsky JL

Abstract
Cystic fibrosis (CF) is the most common lethal inherited disease among Caucasians in North America and a significant portion of Europe. The disease arises from one of many mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator, or CFTR. The most common disease-associated allele, F508del, along with several other mutations affect the folding, transport, and stability of CFTR as it transits from the endoplasmic reticulum (ER) to the plasma membrane, where it functions primarily as a chloride channel. Early data demonstrated that F508del CFTR is selected for ER associated degradation (ERAD), a pathway in which misfolded proteins are recognized by ER-associated molecular chaperones, ubiquitinated, and delivered to the proteasome for degradation. Later studies showed that F508del CFTR that is rescued from ERAD and folds can alternatively be selected for enhanced endocytosis and lysosomal degradation. A number of other disease-causing mutations in CFTR also undergo these events. Fortunately, pharmacological modulators of CFTR biogenesis can repair CFTR, permitting its folding, escape from ERAD, and function at the cell surface. In this article, we review the many cellular checkpoints that monitor CFTR biogenesis, discuss the emergence of effective treatments for CF, and highlight future areas of research on the proteostatic control of CFTR.

PMID: 31936842 [PubMed - in process]

No Cytotoxic and Inflammatory Effects of Empagliflozin and Dapagliflozin on Primary Renal Proximal Tubular Epithelial Cells under Diabetic Conditions In Vitro.

Int J Mol Sci. 2020 Jan 08;21(2):

Authors: Baer PC, Koch B, Freitag J, Schubert R, Geiger H

Abstract
Gliflozins are inhibitors of the renal proximal tubular sodium-glucose co-transporter-2 (SGLT-2), that inhibit reabsorption of urinary glucose and they are able to reduce hyperglycemia in patients with type 2 diabetes. A renoprotective function of gliflozins has been proven in diabetic nephropathy, but harmful side effects on the kidney have also been described. In the current project, primary highly purified human renal proximal tubular epithelial cells (PTCs) have been shown to express functional SGLT-2, and were used as an in vitro model to study possible cellular damage induced by two therapeutically used gliflozins: empagliflozin and dapagliflozin. Cell viability, proliferation, and cytotoxicity assays revealed that neither empagliflozin nor dapagliflozin induce effects in PTCs cultured in a hyperglycemic environment, or in co-medication with ramipril or hydro-chloro-thiazide. Oxidative stress was significantly lowered by dapagliflozin but not by empagliflozin. No effect of either inhibitor could be detected on mRNA and protein expression of the pro-inflammatory cytokine interleukin-6 and the renal injury markers KIM-1 and NGAL. In conclusion, empa- and dapagliflozin in therapeutic concentrations were shown to induce no direct cell injury in cultured primary renal PTCs in hyperglycemic conditions.

PMID: 31936266 [PubMed - in process]

Nanomolar Potency Aminophenyltriazine CFTR Activator Reverses Corneal Epithelial Injury in a Mouse Model of Dry Eye.

J Ocul Pharmacol Ther. 2020 Jan 14;:

Authors: Chen X, Lee S, Zhang T, Duan T, Pasricha ND, Schallhorn JM, Levin MH, Koprivica V, Verkman AS

Abstract
Purpose: Dry eye disorders are a major health care burden. We previously reported the identification of N-methyl-N-phenyl-6-(2,2,3,3-tetrafluoropropoxy)-1,3,5-triazine-2,4-diamine [cystic fibrosis transmembrane conductance regulator (CFTR)act-K267], which activated human wild-type CFTR chloride conductance with EC50 ∼ 30 nM. Here, we report in vivo evidence for CFTRact-K267 efficacy in an experimental mouse model of dry eye using a human compatible ophthalmic vehicle. Methods: CFTR activation in mice in vivo was demonstrated by ocular surface potential difference (OSPD) measurements. Ocular surface pharmacodynamics was measured in tear fluid samples obtained at different times after topical administration of CFTRact-K267. Dry eye was produced by lacrimal duct cautery (LDC) and corneal epithelial injury and was assessed by Lissamine green (LG) staining. Results: OSPD measurements demonstrated a hyperpolarization of -8.6 ± 3 mV (standard error of the mean, 5 mice) in response to CFTRact-K267 exposure in low chloride solution that was reversed by a CFTR inhibitor. Following single-dose topical administration of 2 nmol CFTRact-K267, tear fluid CFTRact-K267 concentration was >500 nM for more than 6 h. Following LDC, corneal surface epithelial injury, as assessed by LG staining, was substantially reversed in 10 of 12 eyes receiving 2 nmol CFTRact-K267 3 times daily starting on day 2, when marked epithelial injury had already occurred. Improvement was seen in 3 of 12 vehicle-treated eyes. Conclusion: These studies provide in vivo evidence in mice for the efficacy of a topical, human use compatible CFTRact-K267 formulation in stimulating chloride secretion and reversing corneal epithelial injury in dry eye.

PMID: 31934802 [PubMed - as supplied by publisher]

Capacitation-associated alkalization in human sperm is differentially controlled at the subcellular level.

J Cell Sci. 2020 Jan 13;:

Authors: Matamoros-Volante A, Treviño CL

Abstract
Capacitation in mammalian sperm involves the accurate balance of intracellular pH (pHi), but the controlling mechanisms are not fully understood, particularly regarding the spatiotemporal regulation of the proteins involved in pHi modulation. Here we employed an image-based flow cytometry technique combined with pharmacological approaches to study pHi dynamics at the subcellular level during capacitation. We found that, upon capacitation induction, sperm cells undergo intracellular alkalization in the head and principal piece regions. The observed localized pHi increases require the initial uptake of HCO3 -, which is mediated by several proteins acting consistently with their subcellular localization. Hv1 proton channel and cAMP-activated Protein Kinase (PKA) antagonists impair alkalization mainly in the principal piece. Na+/HCO3 - cotransporter (NBC) and cystic fibrosis transmembrane regulator (CFTR) antagonists impair alkalization only mildly, predominantly in the head. Motility measurements indicate that inhibition of alkalization in the principal piece prevents the development of hyperactivated motility. Altogether, our findings shed light into the complex control mechanisms of pHi and underscore their importance during human sperm capacitation.

PMID: 31932506 [PubMed - as supplied by publisher]

Cooperativity between Stenotrophomonas maltophilia and Pseudomonas aeruginosa during polymicrobial airway infections.

Infect Immun. 2020 Jan 13;:

Authors: McDaniel MS, Schoeb T, Swords WE

Abstract
Stenotrophomonas maltophilia is a Gram-negative bacterium found ubiquitously in the environment that has historically been regarded as nonpathogenic. S. maltophilia is increasingly observed in patient sputa in cystic fibrosis (CF), and while existing epidemiology indicates that patients with S. maltophilia have poorer diagnoses, its clinical significance remains unclear. Moreover, as multidrug resistance is common among S. maltophilia isolates, treatment options for these infections may be limited. Here we investigated the pathogenicity of S. maltophilia alone and during polymicrobial infection with Pseudomonas aeruginosa. Colonization, persistence, and virulence of S. maltophilia were assessed in experimental respiratory infections of mice. The results of this study indicate that S. maltophilia transiently colonizes the lung accompanied by significant weight loss and immune cell infiltration, and the expression of early inflammatory markers including IL-6, IL-1α, and TNF-α. Importantly, polymicrobial infection with P. aeruginosa elicited significantly higher S. maltophilia counts in bronchoalveolar lavages and lung tissue homogenates. This increase in bacterial load was directly correlated with the density of the P. aeruginosa population, and required viable P. aeruginosa bacteria. Microscopic analysis of biofilms formed in vitro revealed that S. maltophilia formed well-integrated biofilms with P. aeruginosa, and these organisms colocalize in the lung during dual species infection. Based on these results, we conclude that active cellular processes by P. aeruginosa afford significant benefit to S. maltophilia during polymicrobial infections. Further, these results indicate that S. maltophilia may have clinical significance in respiratory infections.

PMID: 31932329 [PubMed - as supplied by publisher]

Vaccines to Overcome Antibiotic Resistance: The Challenge of Burkholderia cenocepacia.

Trends Microbiol. 2020 Jan 10;:

Authors: Scoffone VC, Barbieri G, Buroni S, Scarselli M, Pizza M, Rappuoli R, Riccardi G

Abstract
Cystic fibrosis (CF) patients are at particular risk of infection by microorganisms that are resistant to several antibiotics. About 3% of CF patients are colonized by Burkholderia cenocepacia, and this represents a major threat because of its intrinsic high level of drug resistance and the lack of a safe and effective treatment protocol. The development of anti-Burkholderia vaccines is a valuable and complementary approach, but only a few studies have been reported to date. In this review we discuss recent advances in the vaccine field and how new technologies, including structural reverse vaccinology, could drive the design of an effective vaccine against B. cenocepacia for use in preventive and therapeutic applications.

PMID: 31932141 [PubMed - as supplied by publisher]

Sputum trypsin-like protease activity relates to clinical outcome in cystic fibrosis.

J Cyst Fibros. 2020 Jan 10;:

Authors: Rehill J, Moffitt K, Douglas L, Stuart Elborn J, Jones A, Lorraine Martin S

Abstract
BACKGROUND: In cystic fibrosis (CF) airways excessive levels of serine trypsin-like proteases (TLPs) activate the epithelial sodium channel (ENaC) resulting in airways dehydration and promotion of mucus secretion. Despite this the relationship of TLP activity and clinical outcome has not been studied.
METHODS: We analysed supernatant (sol) prepared from CF sputum from adult CF patients in two study cohorts (29 and 33 samples, respectively). Protease activities were determined by measuring the hydrolysis of peptide-based substrates or by ELISA. Lung function was assessed by spirometry (FEV1). Mortality data was retrospectively obtained and time in months until death or transplantation used for subsequent survival analysis.
RESULTS: TLP activity inversely correlated with percent predicted FEV1 (r = -0.4, p = 0.03) and was greater in individuals who did not survive beyond 5-years from the time of sample collection. A Kaplan-Meier analysis demonstrated significantly reduced survival (p = 0.04) for individuals with high TLP activity [hazard ratio (HR) of 7.21 per log unit TLP activity (p = 0.03)]. In contrast, neutrophil elastase displayed no significant associations with lung function or patient survival. Similar findings were evident in the second study cohort.
CONCLUSIONS: Sputum TLP activity may represent a novel non-invasive biomarker and/or therapeutic target for CF lung disease.

PMID: 31932105 [PubMed - as supplied by publisher]

Exploring the basic mechanisms in Cystic Fibrosis: Promoting data presentation and discussion at the 16th ECFS Basic Science Conference.

J Cyst Fibros. 2020 Jan 10;:

Authors: Callebaut I, Mense M, Farinha CM

Abstract
The revolution in cystic fibrosis treatment is rooted in tremendous interdisciplinary research efforts, which led in recent years to significant progress in precision medicine. Since 2004, a key annual event for the CF research community is the ECFS Basic Science Conference (BSC), which is an ideal venue for deep discussions around topical subjects and fosters basic CF-related research in Europe and beyond. This special issue explores topics that were featured at the 16th ECFS BSC, held in Dubrovnik in March 2019 and provides an overview of recent progress in various fields for understanding disease mechanisms, developing relevant cell and animal models and designing breakthrough therapies. The special issue also identifies a number of the key issues and challenges in the future development of transformative therapies for all patients with CF.

PMID: 31932104 [PubMed - as supplied by publisher]