Mechanical Properties of Human Bronchial Epithelial Cells Expressing Wt- and Mutant CFTR.

Int J Mol Sci. 2020 Apr 21;21(8):

Authors: Carapeto AP, Vitorino MV, Santos JD, Ramalho SS, Robalo T, Rodrigues MS, Farinha CM

Abstract
Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). A single recessive mutation, the deletion of phenylalanine 508 (F508del), causes severe CF and resides on 70% of mutant chromosomes. Disorganization of the actin cytoskeleton has been previously reported in relation to the CF phenotype. In this work, we aimed to understand this alteration by means of Atomic Force Microscopy and Force Feedback Microscopy investigation of mechanical properties of cystic fibrosis bronchial epithelial (CFBE) cells stably transduced with either wild type (wt-) or F508del-CFTR. We show here that the expression of mutant CFTR causes a decrease in the cell's apparent Young modulus as compared to the expression of the wt protein.

PMID: 32326361 [PubMed - in process]

Cystic Fibrosis, CFTR, and Colorectal Cancer.

Int J Mol Sci. 2020 Apr 21;21(8):

Authors: Scott P, Anderson K, Singhania M, Cormier R

Abstract
Cystic fibrosis (CF), caused by biallelic inactivating mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, has recently been categorized as a familial colorectal cancer (CRC) syndrome. CF patients are highly susceptible to early, aggressive colorectal tumor development. Endoscopic screening studies have revealed that by the age of forty 50% of CF patients will develop adenomas, with 25% developing aggressive advanced adenomas, some of which will have already advanced to adenocarcinomas. This enhanced risk has led to new CF colorectal cancer screening recommendations, lowering the initiation of endoscopic screening to age forty in CF patients, and to age thirty in organ transplant recipients. The enhanced risk for CRC also extends to the millions of people (more than 10 million in the US) who are heterozygous carriers of CFTR gene mutations. Further, lowered expression of CFTR is reported in sporadic CRC, where downregulation of CFTR is associated with poor survival. Mechanisms underlying the actions of CFTR as a tumor suppressor are not clearly understood. Dysregulation of Wnt/β-catenin signaling and disruption of intestinal stem cell homeostasis and intestinal barrier integrity, as well as intestinal dysbiosis, immune cell infiltration, stress responses, and intestinal inflammation have all been reported in human CF patients and in animal models. Notably, the development of new drug modalities to treat non-gastrointestinal pathologies in CF patients, especially pulmonary disease, offers hope that these drugs could be repurposed for gastrointestinal cancers.

PMID: 32326161 [PubMed - in process]

Gut Microbiota and Lung Injury.

Adv Exp Med Biol. 2020;1238:55-72

Authors: Tan JY, Tang YC, Huang J

Abstract
Gut microbiota are known to impact multiple organs including the lung. The cross talk between gut microbes and lungs, termed as the "gut-lung axis," is vital for immune response and homeostasis in the airways. In this chapter, we summarized the coordinated development of microorganisms in the gut and lung, exogenous and endogenous factors related to the cross talk, the mechanisms of the gut-lung axis and their dysbiosis in lung diseases. Although the current understanding of the gut-lung axis is in its infancy, several gut microbiota-associated strategies have been designed to treat and prevent lung diseases.

PMID: 32323180 [PubMed - in process]

Chloride - The Underrated Ion in Nociceptors.

Front Neurosci. 2020;14:287

Authors: Wilke BU, Kummer KK, Leitner MG, Kress M

Abstract
In contrast to pain processing neurons in the spinal cord, where the importance of chloride conductances is already well established, chloride homeostasis in primary afferent neurons has received less attention. Sensory neurons maintain high intracellular chloride concentrations through balanced activity of Na+-K+-2Cl- cotransporter 1 (NKCC1) and K+-Cl- cotransporter 2 (KCC2). Whereas in other cell types activation of chloride conductances causes hyperpolarization, activation of the same conductances in primary afferent neurons may lead to inhibitory or excitatory depolarization depending on the actual chloride reversal potential and the total amount of chloride efflux during channel or transporter activation. Dorsal root ganglion (DRG) neurons express a multitude of chloride channel types belonging to different channel families, such as ligand-gated, ionotropic γ-aminobutyric acid (GABA) or glycine receptors, Ca2+-activated chloride channels of the anoctamin/TMEM16, bestrophin or tweety-homolog family, CLC chloride channels and transporters, cystic fibrosis transmembrane conductance regulator (CFTR) as well as volume-regulated anion channels (VRACs). Specific chloride conductances are involved in signal transduction and amplification at the peripheral nerve terminal, contribute to excitability and action potential generation of sensory neurons, or crucially shape synaptic transmission in the spinal dorsal horn. In addition, chloride channels can be modified by a plethora of inflammatory mediators affecting them directly, via protein-protein interaction, or through signaling cascades. Since chloride channels as well as mediators that modulate chloride fluxes are regulated in pain disorders and contribute to nociceptor excitation and sensitization it is timely and important to emphasize their critical role in nociceptive primary afferents in this review.

PMID: 32322187 [PubMed]

The effectiveness of a mobile high-frequency chest wall oscillation (HFCWO) device for airway clearance.

Pediatr Pulmonol. 2020 Apr 22;:

Authors: Leemans G, Belmans D, Van Holsbeke C, Becker B, Vissers D, Ides K, Verhulst S, Van Hoorenbeeck K

Abstract
INTRODUCTION: High-frequency chest wall oscillation (HFCWO) is a commonly prescribed airway clearance technique (ACT) for patients whose ability to expectorate sputum is compromised. This study aimed to assess the effectiveness of a newly developed mobile ACT device (mHFCWO-The Monarch Airway Clearance System) in patients with cystic fibrosis (CF). A standard nonmobile HFCWO device (sHFCWO) was used as a comparator.
METHODOLOGY: This was a randomized, open-label, crossover pilot study. CF patients were treated with each device. Sputum was collected during and after each therapy session, while spirometry tests, Brody score assessment and functional respiratory imaging were performed before and after treatments.
RESULTS: Wet weight of sputum collected during and after treatment was similar for mHFCWO and sHFCWO (6.53 ± 8.55 vs 5.80 ± 5.82; P = .777). Interestingly, the mHFCWO treatment led to a significant decrease in specific airway volume (9.55 ± 9.96 vs 8.74 ± 9.70 mL/L; P < .001), while increasing specific airway resistance (0.10 ± 0.16 vs 0.16 ± 0.23 KPA*S; P < .001). These changes were heterogeneously-distributed throughout the lung tissue and were greater in the distal areas, suggesting a shift of mucus. Changes were accompanied by an overall improvement in the Brody index (57.71 ± 16.55 vs 55.20 ± 16.98; P = .001).
CONCLUSION: The newly developed mobile device provides airway clearance for CF patients comparable to a nonmobile sHFCWO device, yielding a change in airway geometry and patency by the shift of mucus from the more peripheral regions to the central airways.

PMID: 32320537 [PubMed - as supplied by publisher]

Progress in Model Systems of Cystic Fibrosis Mucosal Inflammation to Understand Aberrant Neutrophil Activity.

Front Immunol. 2020;11:595

Authors: Laucirica DR, Garratt LW, Kicic A

Abstract
In response to recurrent infection in cystic fibrosis (CF), powerful innate immune signals trigger polymorphonuclear neutrophil recruitment into the airway lumen. Exaggerated neutrophil proteolytic activity results in sustained inflammation and scarring of the airways. Consequently, neutrophils and their secretions are reliable clinical biomarkers of lung disease progression. As neutrophils are required to clear infection and yet a direct cause of airway damage, modulating adverse neutrophil activity while preserving their pathogen fighting function remains a key area of CF research. The factors that drive their pathological behavior are still under investigation, especially in early disease when aberrant neutrophil behavior first becomes evident. Here we examine the latest findings of neutrophils in pediatric CF lung disease and proposed mechanisms of their pathogenicity. Highlighted in this review are current and emerging experimental methods for assessing CF mucosal immunity and human neutrophil function in the laboratory.

PMID: 32318073 [PubMed - in process]

Chemical, Metabolic, and Cellular Characterization of a FtsZ Inhibitor Effective Against Burkholderia cenocepacia.

Front Microbiol. 2020;11:562

Authors: Chiarelli LR, Scoffone VC, Trespidi G, Barbieri G, Riabova O, Monakhova N, Porta A, Manina G, Riccardi G, Makarov V, Buroni S

Abstract
There is an urgent need for new antimicrobials to treat the opportunistic Gram-negative Burkholderia cenocepacia, which represents a problematic challenge for cystic fibrosis patients. Recently, a benzothiadiazole derivative, C109, was shown to be effective against the infections caused by B. cenocepacia and other Gram-negative and-positive bacteria. C109 has a promising cellular target, the cell division protein FtsZ, and a recently developed PEGylated formulation make it an attractive molecule to counteract Burkholderia infections. However, the ability of efflux pumps to extrude it out of the cell represents a limitation for its use. Here, more than 50 derivatives of C109 were synthesized and tested against Gram-negative species and the Gram-positive Staphylococcus aureus. In addition, their activity was evaluated on the purified FtsZ protein. The chemical, metabolic and cellular stability of C109 has been assayed using different biological systems, including quantitative single-cell imaging. However, no further improvement on C109 was achieved, and the role of efflux in resistance was further confirmed. Also, a novel nitroreductase that can inactivate the compound was characterized, but it does not appear to play a role in natural resistance. All these data allowed a deep characterization of the compound, which will contribute to a further improvement of its properties.

PMID: 32318042 [PubMed]

Microbial clues lead to a diagnosis of cystic fibrosis in late adulthood.

BMJ Case Rep. 2020 Apr 20;13(4):

Authors: Kerr C, Morrissy D, Horgan M, Plant BJ

Abstract
Cystic fibrosis (CF) is the most common life-limiting autosomal recessive genetic disorder among Caucasian populations. The majority of CF cases are diagnosed in childhood; however, increasing numbers of adults are being diagnosed with the condition. We present the case of a 65-year-old Irish woman presenting with a chronic cough and a history of recurrent respiratory tract infections. Staphylococcus aureus, Scedosporium apiospermum and Stenotrophomonas maltophilia were grown from bronchoalveolar lavage raising suspicion for CF. Sweat testing was negative; however, genetic testing revealed the presence of ∆F508 and R117H CF mutations, the latter mutation conferring a milder form of CF. The patient commenced treatment with the cystic fibrosis transmembrane conductance regulator (CFTR) potentiator medication ivacaftor to good effect. Novel CFTR potentiators and modulators have significant potential to benefit morbidity and mortality in this group. In this case, the microbiological results were key in pursuing genetic testing and diagnosing CF.

PMID: 32317365 [PubMed - in process]

Establishment of a Recombinant AAV2/HBoV1 Vector Production System in Insect Cells.

Genes (Basel). 2020 Apr 17;11(4):

Authors: Deng X, Zou W, Yan Z, Qiu J

Abstract
We have previously developed an rAAV2/HBoV1 vector in which a recombinant adeno-associated virus 2 (rAAV2) genome is pseudopackaged into a human bocavirus 1 (HBoV1) capsid. Recently, the production of rAAV2/HBoV1 in human embryonic kidney (HEK) 293 cells has been greatly improved in the absence of any HBoV1 nonstructural proteins (NS). This NS-free production system yields over 16-fold more vectors than the original production system that necessitates NS expression. The production of rAAV with infection of baculovirus expression vector (BEV) in the suspension culture of Sf9 insect cells is highly efficient and scalable. Since the replication of the rAAV2 genome in the BEV system is well established, we aimed to develop a BEV system to produce the rAAV2/HBoV1 vector in Sf9 cells. We optimized the usage of translation initiation signals of the HBoV1 capsid proteins (Cap), and constructed a BEV Bac-AAV2Rep-HBoV1Cap, which expresses the AAV2 Rep78 and Rep52 as well as the HBoV1 VP1, VP2, and VP3 at the appropriate ratios. We found that it is sufficient as a trans helper to the production of rAAV2/HBoV1 in Sf9 cells that were co-infected with the transfer Bac-AAV2ITR-GFP-luc that carried a 5.4-kb oversized rAAV2 genome with dual reporters. Further study found that incorporation of an HBoV1 small NS, NP1, in the system maximized the viral DNA replication and thus the rAAV2/HBoV1 vector production at a level similar to that of the rAAV2 vector in Sf9 cells. However, the transduction potency of the rAAV2/HBoV1 vector produced from BEV-infected Sf9 cells was 5-7-fold lower in polarized human airway epithelia than that packaged in HEK293 cells. Transmission electron microscopy analysis found that the vector produced in Sf9 cells had a high percentage of empty capsids, suggesting the pseudopackage of the rAAV2 genome in HBoV1 capsid is not as efficient as in the capsids of AAV2. Nevertheless, our study demonstrated that the rAAV2/HBoV1 can be produced in insect cells with BEVs at a comparable yield to rAAV, and that the highly efficient expression of the HBoV1 capsid proteins warrants further optimization.

PMID: 32316599 [PubMed - in process]

Sympatho-Vagal Dysfunction in Patients with End-Stage Lung Disease Awaiting Lung Transplantation.

J Clin Med. 2020 Apr 17;9(4):

Authors: Tobaldini E, D Rodrigues G, Mantoan G, Monti A, Coti Zelati G, Cirelli C, Tarsia P, Morlacchi LC, Rossetti V, Righi I, Nosotti M, da S Soares PP, Montano N, Aliberti S, Blasi F

Abstract
Although the literature demonstrates that cardiac autonomic control (CAC) might be impaired in patients with chronic pulmonary diseases, the interplay between CAC and disease severity in end-stage lung disease has not been studied yet. We investigated the effects of end-stage lung disease on CAC through the analysis of heart rate variability (HRV) among patients awaiting lung transplantation. Forty-nine patients on the waiting list for lung transplantation (LTx; 19 men, age 38 ± 15 years) and 49 healthy non-smoking controls (HC; 22 men, age 40 ± 16 years) were enrolled in a case-control study at Policlinico Hospital in Milan, Italy. LTx patients were divided into two groups, according to disease severity evaluated by the Lung Allocation Score (LAS). To assess CAC, electrocardiogram (ECG) and respiration were recorded at rest for 10 min in supine position and for 10 min during active standing. Spectral analysis identified low and high frequencies (LF, sympathetic, and HF, vagal). Symbolic analysis identified three patterns, i.e., 0V% (sympathetic) and 2UV% and 2LV% (vagal). Compared to HCs, LTx patients showed higher markers of sympathetic modulation and lower markers of vagal modulation. However, more severely affected LTx patients, compared to less severely affected ones, showed an autonomic profile characterized by loss of sympathetic modulation and predominant vagal modulation. This pattern can be due to a loss of sympathetic rhythmic oscillation and a subsequent prevalent respiratory modulation of heart rate in severely affected patients.

PMID: 32316428 [PubMed]

Fast chemical force microscopy demonstrates that glycopeptidolipids define nanodomains of varying hydrophobicity on mycobacteria.

Nanoscale Horiz. 2020 Apr 21;:

Authors: Viljoen A, Viela F, Kremer L, Dufrêne YF

Abstract
Mycobacterium abscessus is an emerging multidrug-resistant bacterial pathogen causing severe lung infections in cystic fibrosis patients. A remarkable trait of this mycobacterial species is its ability to form morphologically smooth (S) and rough (R) colonies. The S-to-R transition is caused by the loss of glycopeptidolipids (GPLs) in the outer layer of the cell envelope and correlates with an increase in cording and virulence. Despite the physiological and medical importance of this morphological transition, whether it involves changes in cell surface properties remains unknown. Herein, we combine recently developed quantitative imaging (QI) atomic force microscopy (AFM) with hydrophobic tips to quantitatively map the surface structure and hydrophobicity of M. abscessus at high spatiotemporal resolution, and to assess how these properties are modulated by the S-to-R transition and by treatment with an inhibitor of the mycolic acid transporter MmpL3. We discover that loss of GPLs leads to major modifications in surface hydrophobicity, without any apparent change in cell surface ultrastructure. While R bacilli are homogeneously hydrophobic, S bacilli feature unusual variations of nanoscale hydrophobic properties. These previously undescribed cell surface nanodomains are likely to play critical roles in bacterial adhesion, aggregation, phenotypic heterogeneity and transmission, and in turn in virulence and pathogenicity. Our study also suggests that MmpL3 inhibitors show promise in nanomedicine as chemotherapeutic agents to interfere with the highly hydrophobic nature of the mycobacterial cell wall. The advantages of QI-AFM with hydrophobic tips are the ability to map chemical and structural properties simultaneously and at high resolution, applicable to a wide range of biosystems.

PMID: 32314749 [PubMed - as supplied by publisher]

A novel hemizygous loss-of-function mutation in ADGRG2 causes male infertility with congenital bilateral absence of the vas deferens.

J Assist Reprod Genet. 2020 Apr 20;:

Authors: Wu H, Gao Y, Ma C, Shen Q, Wang J, Lv M, Liu C, Cheng H, Zhu F, Tian S, Elshewy N, Ni X, Tan Q, Xu X, Zhou P, Wei Z, Zhang F, He X, Cao Y

Abstract
PURPOSE: Cystic fibrosis transmembrane conductance regulator (CFTR) and adhesion G protein-coupled receptor G2 (ADGRG2) have been identified as the main pathogenic genes in congenital bilateral absence of the vas deferens (CBAVD), which is an important cause of obstructive azoospermia. This study aimed to identify the disease-causing gene in two brothers with CBAVD from a Chinese consanguineous family and reveal the intracytoplasmic sperm injection (ICSI) outcomes in these patients.
METHODS: Whole-exome sequencing and Sanger sequencing were used to identify the candidate pathogenic genes. Real-time polymerase chain reaction, immunohistochemistry, and immunofluorescence were used to assess the expression of the mutant gene. Moreover, the ICSI results from both patients were retrospectively reviewed.
RESULTS: A novel hemizygous loss-of-function mutation (c.G118T: p.Glu40*) in ADGRG2 was identified in both patients with CBAVD. This mutation is absent from the human genome databases and causes an early translational termination in the third exon of ADGRG2. Expression analyses showed that both the ADGRG2 mRNA and the corresponding protein were undetectable in the proximal epididymal tissue of ADGRG2-mutated patients. ADGRG2 expression was restricted to the apical membranes of non-ciliated epithelia in human efferent ducts, which was consistent with a previous report in mice. Both ADGRG2-mutated patients had normal spermatogenesis and had successful clinical outcomes following ICSI.
CONCLUSIONS: Our study verifies the pathogenic role of ADGRG2 in X-linked CBAVD and broadens the spectrum of ADGRG2 mutations. In addition, we found positive ICSI outcomes in the two ADGRG2-mutated CBAVD patients.

PMID: 32314195 [PubMed - as supplied by publisher]

A central role of the endoplasmic reticulum in the cell emerges from its functional contact sites with multiple organelles.

Cell Mol Life Sci. 2020 Apr 20;:

Authors: Almeida C, Amaral MD

Abstract
Early eukaryotic cells emerged from the compartmentalization of metabolic processes into specific organelles through the development of an endomembrane system (ES), a precursor of the endoplasmic reticulum (ER), which was essential for their survival. Recently, substantial evidence emerged on how organelles communicate among themselves and with the plasma membrane (PM) through contact sites (CSs). From these studies, the ER-the largest single structure in eukaryotic cells-emerges as a central player communicating with all organelles to coordinate cell functions and respond to external stimuli to maintain cellular homeostasis. Herein we review the functional insights into the ER-CSs with other organelles in a physiological perspective. We hypothesize that, in addition to the primitive role by the ES in the appearance of proto-eukaryotes, its successor-the ER-emerges as the key coordinator of inter-organelle/PM communication. The ER thus appears to be the 'maestro' driving eukaryotic cell evolution by incorporating new functions/organelles, while remaining the real coordinator overarching cellular functions and orchestrating them with the external milieu.

PMID: 32313974 [PubMed - as supplied by publisher]

Evaluation of a five-year predicted survival model for cystic fibrosis in later time periods.

Sci Rep. 2020 Apr 20;10(1):6602

Authors: Liou TG, Kartsonaki C, Keogh RH, Adler FR

Abstract
We evaluated a multivariable logistic regression model predicting 5-year survival derived from a 1993-1997 cohort from the United States Cystic Fibrosis (CF) Foundation Patient Registry to assess whether therapies introduced since 1993 have altered applicability in cohorts, non-overlapping in time, from 1993-1998, 1999-2004, 2005-2010 and 2011-2016. We applied Kaplan-Meier statistics to assess unadjusted survival. We tested logistic regression model discrimination using the C-index and calibration using Hosmer-Lemeshow tests to examine original model performance and guide updating as needed. Kaplan-Meier age-adjusted 5-year probability of death in the CF population decreased substantially during 1993-2016. Patients in successive cohorts were generally healthier at entry, with higher average age, weight and lung function and fewer pulmonary exacerbations annually. CF-related diabetes prevalence, however, steadily increased. Newly derived multivariable logistic regression models for 5-year survival in new cohorts had similar estimated coefficients to the originals. The original model exhibited excellent calibration and discrimination when applied to later cohorts despite improved survival and remains useful for predicting 5-year survival. All models may be used to stratify patients for new studies, and the original coefficients may be useful as a baseline to search for additional but rare events that affect survival in CF.

PMID: 32313191 [PubMed - in process]

The bidirectional relationship between CFTR and lipids.

Commun Biol. 2020 Apr 20;3(1):179

Authors: Cottrill KA, Farinha CM, McCarty NA

Abstract
Cystic Fibrosis (CF) is the most common life-shortening genetic disease among Caucasians, resulting from mutations in the gene encoding the Cystic Fibrosis Transmembrane conductance Regulator (CFTR). While work to understand this protein has resulted in new treatment strategies, it is important to emphasize that CFTR exists within a complex lipid bilayer - a concept largely overlooked when performing structural and functional studies. In this review we discuss cellular lipid imbalances in CF, mechanisms by which lipids affect membrane protein activity, and the specific impact of detergents and lipids on CFTR function.

PMID: 32313074 [PubMed - in process]

Endobronchial valve treatment of persistent alveolopleural fistulae in a patient with cystic fibrosis and empyema.

J Cyst Fibros. 2020 Apr 18;:

Authors: Bongers KS, De Cardenas J

Abstract
Persistent air leak (PAL) is a common problem after secondary pneumothorax due to cystic fibrosis (CF). These leaks, caused by either bronchopleural or alveolopleural fistula, are associated with higher morbidity and mortality [1]. Air leaks are traditionally treated with chronic chest tube drainage, chemical pleurodesis, or autologous blood patching in non-surgical candidates [1]. However, these strategies can increase infectious risk or pleural scarring, which are associated with poorer lung transplant surgical outcomes. Endobronchial valve (EBV) placement, while FDA-approved for use in both some surgical PALs and bronchoscopic volume reduction therapy, is one alternative option, but it could theoretically increase the risk of infection, especially in CF patients. Here, we report the case of a CF patient under evaluation for lung transplant who received EBVs for PAL after bilateral secondary spontaneous pneumothoraces.

PMID: 32312675 [PubMed - as supplied by publisher]

Highly selective and sensitive online measurement of trace exhaled HCN by acetone-assisted negative photoionization time-of-flight mass spectrometry with in-source CID.

Anal Chim Acta. 2020 May 15;1111:31-39

Authors: Xie Y, Li Q, Hua L, Chen P, Hu F, Wan N, Li H

Abstract
Exhaled hydrogen cyanide (HCN) has been extensively investigated as a promising biomarker of the presence of Pseudomonas aeruginosa in the airways of patients with cystic fibrosis (CF) disease. Its concentration profile for exhalation can provide useful information for medical disease diagnosis and therapeutic procedures. However, the complexity of breath gas, like high humidity, carbon dioxide (CO2) and trace organic compounds, usually leads to quantitative error, poor selectivity and sensitivity for HCN with some of existing analytical techniques. In this work, acetone-assisted negative photoionization (AANP) based on a vacuum ultraviolet (VUV) lamp with a time-of- flight mass spectrometer (AANP-TOFMS) was firstly proposed for online measurement of trace HCN in human breath. In-source collision-induced dissociation (CID) was adopted for sensitivity improvement and the signal response of the characteristic ion CN- (m/z 26) was improved by about 24-fold. For accurate and reliable analysis of the exhaled HCN, matrix influences in the human breath including humidity and CO2 were investigated, respectively. A Nafion tube was used for online dehumidification of breath samples. Matrix-adapted calibration in the concentration range of 0.5-50 ppbv with satisfactory dynamic linearity and repeatability was obtained. The limit of quantitation (LOQ) for HCN at 0.5 ppbv was achieved in the presence of 100% relative humidity and 4% CO2. Finally, the method was successfully applied for online determination of human mouth- and nose-exhaled HCN, and the nose-exhaled HCN were proved to be reliable for assessing systemic HCN levels for individuals. The results are encouraging and highlight the potential of AANP-TOFMS with in-source CID as a selective, accurate, sensitive and noninvasive technique for determination of the exhaled HCN for CF clinical diagnosis and HCN poisoning assessment.

PMID: 32312394 [PubMed - in process]

CYSTIC FIBROSIS AS A CAUSE OF MALABSORPTION AND INCREASED REQUIREMENT OF L-THYROXINE.

Thyroid. 2020 Apr 20;:

Authors: Giuffrida G, Magazzu G, Campenni A, Lucanto MC, Trimarchi F, Cannavò S, Ruggeri RM

Abstract
Cystic fibrosis (CF), a monogenic disease from mutations in the CFTR gene, causes pancreatic and biliary insufficiency with impaired absorption of nutrients and drugs. Unlike other malabsorption disorders, no data are available in literature on levothyroxine (L-T4) absorption in these patients. Herein we report L-T4 malabsorption and increased requirement in two hypothyroid patients with CF. Both patients (patient #1, a 44-years-old female; patient #2, a 39-years-old male), affected by post-surgical hypothyroidism, were unable to reach adequate TSH levels despite a daily L-T4 dosage largely exceeding their weight-estimated values, even after multiple increases. They did not take medications altering L-T4 absorption or metabolism. In both patients an L-T4 absorption test was performed, under clinical control. Serum concentrations of TSH, total (T4) and free-thyroxine (FT4) were measured before ingestion of L-T4, then every hour for 4 h and 24 h later. Area under the curve (AUC) for T4 and FT4 was calculated. After L-T4 load, T4 and FT4 values remained below the lower reference range limit in patient #1; a slight increase towards normal levels, but under a 2.5-fold cut-off was observed in patient #2, thus confirming a true malabsorption in both subjects. The AUC were similar in the two tests. Both patients were then shifted towards liquid L-T4 formulation, reaching stable target TSH ranges. CF should be included among the digestive diseases causing L-T4 malabsorption, likely due to the combination of pancreatic insufficiency, chronic intestinal inflammation and reduced biliary salts production. L-T4 oral liquid formulation allows to overcome the reduced absorption of L-T4 in these patients, in which L-T4 absorption test can confirm a real malabsorption, leading to more tailored choices for hypothyroidism management.

PMID: 32312180 [PubMed - as supplied by publisher]

Dried blood spot-based metabolomic profiling in adults with cystic fibrosis.

J Proteome Res. 2020 Apr 21;:

Authors: Al-Qahtani W, Abdel Jabar M, Masood A, Jacob M, Nizami I, Dasouki M, Abdel Rahman AM

Abstract
Mucoviscidosis of the respiratory, gastrointestinal and genitourinary tracts is the major pathology in patients with cystic fibrosis (CF), a lethal monogeneic pan-ethnic and multi-systemic disease most commonlyidentified in Caucasians. Currently, the measurement of Immuno Reactive Trypsinogen (IRT) in dry blood spots (DBS) is the gold-standard method for initial newborn screening for CF, followed by targeted CFTR mutation analysis, and ultimate confirmation with abnormally elevatedsweat chloride. Previous metabolomics studies in patients with CF reported on different biomarkers such as breath 2-aminoacetophenone produced during acute and chronic infection in human tissues, including the lungs of CF patients. Herein, we used liquid and gas chromatography-mass spectrometry-based targeted metabolomics profiling to identify potentiallyreliable, sensitive, and specific biomarkers in dry blood spots (DBS) collected from 69 young and adult people including CF patients (n= 39) and healthy control (n=30).A distinctive metabolic profile including 26 significantly differentially expressed metabolites involving the amino acids, glycolysis, mitochondrial and peroxisomal metabolism and sorbitol pathways was identified. Specifically, the osmolyte (sorbitol) was remarkably down-regulated in CF patients compared to healthy controls indicating perturbation in the sorbitol pathway which may be responsible for the mucoviscidosis seen in patients with CF. The significance of our findings is supported by the clinical utility of inhaled mannitol and hypertonic saline in patients with CF. The systemic administration of sorbitol in such patients may confer additional benefits beyond the respiratory system especially in those with misfolded CFTR proteins.

PMID: 32312052 [PubMed - as supplied by publisher]

The CF Canada-Sick Kids Program in individual CF therapy: A resource for the advancement of personalized medicine in CF.

J Cyst Fibros. 2019 01;18(1):35-43

Authors: Eckford PDW, McCormack J, Munsie L, He G, Stanojevic S, Pereira SL, Ho K, Avolio J, Bartlett C, Yang JY, Wong AP, Wellhauser L, Huan LJ, Jiang JX, Ouyang H, Du K, Klingel M, Kyriakopoulou L, Gonska T, Moraes TJ, Strug LJ, Rossant J, Ratjen F, Bear CE

Abstract
BACKGROUND: Therapies targeting certain CFTR mutants have been approved, yet variations in clinical response highlight the need for in-vitro and genetic tools that predict patient-specific clinical outcomes. Toward this goal, the CF Canada-Sick Kids Program in Individual CF Therapy (CFIT) is generating a "first of its kind", comprehensive resource containing patient-specific cell cultures and data from 100 CF individuals that will enable modeling of therapeutic responses.
METHODS: The CFIT program is generating: 1) nasal cells from drug naïve patients suitable for culture and the study of drug responses in vitro, 2) matched gene expression data obtained by sequencing the RNA from the primary nasal tissue, 3) whole genome sequencing of blood derived DNA from each of the 100 participants, 4) induced pluripotent stem cells (iPSCs) generated from each participant's blood sample, 5) CRISPR-edited isogenic control iPSC lines and 6) prospective clinical data from patients treated with CF modulators.
RESULTS: To date, we have recruited 57 of 100 individuals to CFIT, most of whom are homozygous for F508del (to assess in-vitro: in-vivo correlations with respect to ORKAMBI response) or heterozygous for F508del and a minimal function mutation. In addition, several donors are homozygous for rare nonsense and missense mutations. Nasal epithelial cell cultures and matched iPSC lines are available for many of these donors.
CONCLUSIONS: This accessible resource will enable development of tools that predict individual outcomes to current and emerging modulators targeting F508del-CFTR and facilitate therapy discovery for rare CF causing mutations.

PMID: 29685812 [PubMed - indexed for MEDLINE]