Am J Physiol Lung Cell Mol Physiol. 2023 Dec 12. doi: 10.1152/ajplung.00253.2023. Online ahead of print.

ABSTRACT

Cystic Fibrosis (CF) results in a reduction in the volume of airway surface liquid, increased accumulation of viscous mucus, persistent antibiotic resistant lung infections that cause chronic inflammation and a decline in lung function. More than fifty percent of adults with CF are chronically colonized by Pseudomonas aeruginosa (P. aeruginosa), the primary reason for morbidity and mortality in people with CF (pwCF). Although highly effective modulator therapy (HEMT) is an important part of disease management in CF, HEMT does not eliminate P. aeruginosa or lung inflammation. Thus, new treatments are required to reduce lung infection and inflammation in CF. In a previous in vitro study we demonstrated that primary human bronchial epithelial cells (HBEC) secrete extracellular vesicles (EVs) that block the ability of P. aeruginosa to form biofilms by reducing the abundance of several proteins necessary for biofilm formation as well as enhancing the sensitivity of P. aeruginosa to beta-lactam antibiotics. In this study using a CF mouse model of P. aeruginosa infection we demonstrate that intratracheal administration of EVs secreted by HBEC reduced P. aeruginosa lung burden and several pro-inflammatory cytokines including IFN-γ, TNF-α, and MIP-1β in bronchoalveolar fluid (BALF), even in the absence of antibiotics. Moreover, EVs decreased neutrophils in BALF. Thus, EVs secreted by HBEC reduce the lung burden of P. aeruginosa, decrease inflammation and reduce neutrophils in a CF mouse model. These results suggest that HBEC via the secretion of EVs may play an important role in the immune response to P. aeruginosa lung infection.

PMID:38084406 | DOI:10.1152/ajplung.00253.2023

Am J Physiol Lung Cell Mol Physiol. 2023 Dec 12. doi: 10.1152/ajplung.00219.2023. Online ahead of print.

ABSTRACT

Cystic fibrosis related diabetes (CFRD) affects 40-50% of adults with CF and is associated with a decline in respiratory health. The microbial flora of the lung is known to change with the development of CF disease, but how CFRD affects the microbiome has not been described. We analysed the microbiome in sputa from 14 people with CF and 14 with CFRD and two who were classed as pre-CFRD by extracting DNA and amplifying the variable V3-V4 region of the microbial 16S gene by PCR. Sequences were analysed and source identified to genus level. We found that the a-diversity of the microbiome using Shannon's diversity index was increased in CFRD compared to CF. Bray Curtis dissimilarity analysis showed that there was separation of the microbiomes in CF and CFRD sputa. The most abundant phyla identified in the sputum samples were Firmicutes and Proteobacteria, Actinobacteriota and Bacteroidota and the ratio of Firmicutes/Bacteroidota was reduced in CFRD compared to CF. Pseudomonas, Azhorizophilus, Porphyromonas and Actinobacillus were more abundant in CFRD compared to CF whereas Staphylococcus was less abundant. The relative abundance of these genera did not correlate with age, some correlated with a decline in FEV1/FVC but all correlated with HbA1c indicating that development of CFRD mediates further changes to the respiratory microbiome in CF.

PMID:38084404 | DOI:10.1152/ajplung.00219.2023

Int J Pharm. 2023 Dec 9:123693. doi: 10.1016/j.ijpharm.2023.123693. Online ahead of print.

ABSTRACT

Optimizing a sustained-release drug delivery system for the treatment of cystic fibrosis is crucial for decreasing the dosing frequency and improving patients' compliance with the treatment regimen. In the current work, we developed an injectable PLGA microparticle formulation loaded with ivacaftor, a CFTR potentiator that increases the open probability of the CFTR anion channel, using a single emulsion solvent evaporation technique. We aimed to study the effect of different parameters on the characteristics of the prepared formulations to select an optimized microparticle formulation to be used in the in vivo pharmacokinetic study in mice. First, ivacaftor-loaded microparticles were prepared while varying the formulation parameters to study their effect on the formulations' size, morphology, drug loading, encapsulation efficiency, and in vitro release profiles. All the prepared microparticles showed smooth spherical surfaces with internal diameters of 1.91- 6.93 µm, drug loading (DL) of 3.91 - 10.3%, percent encapsulation efficiencies (%EE) of 26.6 - 100%, and an overall slow cumulative release profile. We selected one formulation that showed the best combined %DL and %EE values (8.25, and 90.7%, respectively), with an average particle size of 6.83 µm, and a slow bi-phasic in vitro release profile (up to 6 weeks) to study its in vivo pharmacokinetics in comparison to solubilized ivacaftor following their subcutaneous (SC) and intravenous (IV) administration to mice, respectively. The injected microparticle formulation showed steady plasma levels of ivacaftor over a period of 28 days, and a 6-fold increase in AUC 0 - t (71.6 µg/mL*h) compared to the intravenously injected soluble ivacaftor (12.3 µg/mL*h). Our results suggest that this novel ivacaftor-loaded microparticle formulation could potentially eliminate the need for the frequent daily administration of ivacaftor by people with cystic fibrosis which could improve their compliance and ensure successful treatment outcomes.

PMID:38081555 | DOI:10.1016/j.ijpharm.2023.123693

Naunyn Schmiedebergs Arch Pharmacol. 2023 Dec 11. doi: 10.1007/s00210-023-02882-y. Online ahead of print.

ABSTRACT

Asthma, lung cancer, cystic fibrosis, tuberculosis, acute respiratory distress syndrome, chronic obstructive pulmonary disease, and COVID-19 are few examples of inflammatory lung conditions that cause cytokine release syndrome. It can initiate a widespread inflammatory response and may activate several inflammatory pathways that cause multiple organ failures leading to increased number of deaths and increased prevalence rates around the world. Nanotechnology-based therapeutic modalities such as nanoparticles, liposomes, nanosuspension, monoclonal antibodies, and vaccines can be used in the effective treatment of inflammatory lung diseases at both cellular and molecular levels. This would also help significantly in the reduction of patient mortality. Therefore, nanotechnology could be a potent platform for repurposing current medications in the treatment of inflammatory lung diseases. The aim and approach of this article are to highlight the clinical manifestations of cytokine storm in inflammatory lung diseases along with the advances and potential applications of nanotechnology-based therapeutics in the management of cytokine storm. Further in-depth studies are required to understand the molecular pathophysiology, and how nanotechnology-based therapeutics can help to effectively combat this problem.

PMID:38078921 | DOI:10.1007/s00210-023-02882-y

Biofilm. 2023 Nov 25;6:100166. doi: 10.1016/j.bioflm.2023.100166. eCollection 2023 Dec 15.

ABSTRACT

OBJECTIVES: Structural or mucus hypersecretory pulmonary diseases such as cystic fibrosis (CF), wherein viscous mucus accumulates and clearance functions are impaired, predispose people to lung infection by inhaled bacteria that form biofilm aggregates. Nontuberculous mycobacteria (NTM), primarily Mycobacterium abscessus and Mycobacterium avium, are the growing cause of these lung infections and are extremely challenging to treat due to antibiotic recalcitrance. Better therapeutic approaches are urgently needed. We developed a humanized monoclonal antibody (HuTipMab) directed against a biofilm structural linchpin, the bacterial DNABII proteins, that rapidly disrupts biofilms and generates highly vulnerable newly released bacteria (NRel).

METHODS: HuTipMab's ability to recognize HupB, NTM's DNABII homologue was determined by ELISA. Relative ability of HuTipMab to disrupt biofilms formed by lab-passaged and clinical isolates of NTM was assessed by CLSM. Relative sensitivity of NTM NRel to antibiotic killing compared to when grown planktonically was evaluated by plate count.

RESULTS: HuTipMab recognized HupB and significantly disrupted NTM biofilms in a time- and dose-dependent manner. Importantly, NTM NRel of lab-passaged and clinical isolates were now highly sensitive to killing by amikacin and azithromycin.

CONCLUSIONS: If successful, this combinatorial treatment strategy would empower existing antibiotics to more effectively kill NTM newly released from a biofilm by HuTipMab and thereby both improve clinical outcomes and perhaps decrease length of antibiotic treatment for people that are NTM culture-positive.

PMID:38078059 | PMC:PMC10698573 | DOI:10.1016/j.bioflm.2023.100166

Front Immunol. 2023 Nov 22;14:1295921. doi: 10.3389/fimmu.2023.1295921. eCollection 2023.

ABSTRACT

INTRODUCTION: Neutrophil extracellular traps (NETs) are structures released by neutrophils in response to various infections. NETs have a biocidal role and have been demonstrated to be effective against bacteria, fungi, viruses, and parasites. Depending on the situation, NETs can protect the host from pathogen invasion or contribute to the development of autoimmune diseases such as cystic fibrosis and rheumatoid arthritis. In this study, we aimed to investigate the occurrence of NET as one of the components in upper respiratory tract secretions in infectious and allergic diseases.

METHODS: Nasal mucus was collected from donors diagnosed with infectious rhinitis or allergic rhinitis. The extracellular DNA content was determined using SytoxGreen staining, and the total protein pool was determined using the microBCA method. Micrococcal nuclease was used to digest the samples and ELISA was employed to identify the NET proteins. The enzymatic activity of elastase was determined.

RESULTS: Our findings showed that nasal mucus collected from patients with infectious rhinosinusitis contained extracellular DNA that could come from a variety of sources, responsible for increasing the density and viscosity of secretions, as well as NETs proteins. The identified enzymatic activity of NET elastase indicates the possible irritation of nasal tissues. However, the DNA content was not identified in the samples from allergic patients. In addition, we have shown in preliminary studies that therapy using N-acetylcysteine can liquefy nasal secretions.

DISCUSSION: The study suggests that the composition of nasal mucus varies according to the cause of mucosal irritation. The presence of DNA and NET proteins can have severe consequences for the therapeutic process prolonging treatment. The low viscosity of nasal mucus in allergic patients facilitates mucosal flushing and the removal of allergens. Understanding the occurrence and role of NETs in various respiratory diseases is critical for developing effective treatment strategies that consider the complex interaction between the immune system and pathogens. The results of this study suggest that NETs may be present in upper respiratory tract secretions with an infectious background, supporting basic defense mechanisms using eosinophils and EETs. Further research is needed to explore the potential of NETs as a therapeutic target in respiratory diseases.

PMID:38077338 | PMC:PMC10702990 | DOI:10.3389/fimmu.2023.1295921

Front Genome Ed. 2023 Nov 22;5:1271813. doi: 10.3389/fgeed.2023.1271813. eCollection 2023.

ABSTRACT

Considerable effort has been devoted to developing adeno-associated virus (AAV)-based vectors for gene therapy in cystic fibrosis (CF). As a result of directed evolution and capsid shuffling technology, AAV capsids are available with widespread tropism for airway epithelial cells. For example, AAV2.5T and AAV6.2 are two evolved capsids with improved airway epithelial cell transduction properties over their parental serotypes. However, limited research has been focused on identifying their specific cellular tropism. Restoring cystic fibrosis transmembrane conductance regulator (CFTR) expression in surface columnar epithelial cells is necessary for the correction of the CF airway phenotype. Basal cells are a progenitor population of the conducting airways responsible for replenishing surface epithelial cells (including secretory cells and ionocytes), making correction of this cell population vital for a long-lived gene therapy strategy. In this study, we investigate the tropism of AAV capsids for three cell types in primary cultures of well-differentiated human airway epithelial (HAE) cells and primary human airway basal cells. We observed that AAV2.5T transduced surface epithelial cells better than AAV6.2, while AAV6.2 transduced airway basal cells better than AAV2.5T. We also investigated a recently developed capsid, AAV6.2FF, which has two surface tyrosines converted to phenylalanines. Next, we incorporated reciprocal mutations to create AAV capsids with further improved surface and basal cell transduction characteristics. Lastly, we successfully employed a split-intein approach using AAV to deliver an adenine base editor (ABE) to repair the CFTR R553X mutation. Our results suggest that rational incorporation of AAV capsid mutations improves AAV transduction of the airway surface and progenitor cells and may ultimately lead to improved pulmonary function in people with CF.

PMID:38077224 | PMC:PMC10702583 | DOI:10.3389/fgeed.2023.1271813

bioRxiv. 2023 Nov 29:2023.11.28.569028. doi: 10.1101/2023.11.28.569028. Preprint.

ABSTRACT

The human airway contains specialized rare epithelial cells whose roles in respiratory disease are not well understood. Ionocytes express the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), while chemosensory tuft cells express asthma-associated alarmins. However, surprisingly, exceedingly few mature tuft cells have been identified in human lung cell atlases despite the ready identification of rare ionocytes and neuroendocrine cells. To identify human rare cell progenitors and define their lineage relationship to mature tuft cells, we generated a deep lung cell atlas containing 311,748 single cell RNA-Seq (scRNA-seq) profiles from discrete anatomic sites along the large and small airways and lung lobes of explanted donor lungs that could not be used for organ transplantation. Of 154,222 airway epithelial cells, we identified 687 ionocytes (0.45%) that are present in similar proportions in both large and small airways, suggesting that they may contribute to both large and small airways pathologies in CF. In stark contrast, we recovered only 3 mature tuft cells (0.002%). Instead, we identified rare bipotent progenitor cells that can give rise to both ionocytes and tuft cells, which we termed tuft-ionocyte progenitor cells (TIP cells). Remarkably, the cycling fraction of these TIP cells was comparable to that of basal stem cells. We used scRNA-seq and scATAC-seq to predict transcription factors that mark this novel rare cell progenitor population and define intermediate states during TIP cell lineage transitions en route to the differentiation of mature ionocytes and tuft cells. The default lineage of TIP cell descendants is skewed towards ionocytes, explaining the paucity of mature tuft cells in the human airway. However, Type 2 and Type 17 cytokines, associated with asthma and CF, diverted the lineage of TIP cell descendants in vitro , resulting in the differentiation of mature tuft cells at the expense of ionocytes. Consistent with this model of mature tuft cell differentiation, we identify mature tuft cells in a patient who died from an asthma flare. Overall, our findings suggest that the immune signaling pathways active in asthma and CF may skew the composition of disease-relevant rare cells and illustrate how deep atlases are required for identifying physiologically-relevant scarce cell populations.

PMID:38076853 | PMC:PMC10705390 | DOI:10.1101/2023.11.28.569028

Front Microbiol. 2023 Nov 21;14:1274280. doi: 10.3389/fmicb.2023.1274280. eCollection 2023.

ABSTRACT

INTRODUCTION: The Burkholderia cepacia complex (BCC) encompasses a group of at least 22 genetically distinct gram-negatives bacterial species ubiquitous in nature. Recognised as a group of genetically and phenotypically flexible species, the BCC inhabits diverse ecological niches causing both plant and human diseases. Comparative genomic analysis provides an in depth understanding into the population biology, phylogenetic relationship, and genomic architecture of species.

METHODS: Here, we genomically characterise Burkholderia anthina isolated from patients with chronic lung infections, an understudied pathogen within the Burkholderia cepacia complex.

RESULTS: We demonstrate that B. anthina is polyphyletic and constitutes two distinct evolutionary lineages. Core- and pan-genome analyses demonstrated substantial metabolic diversity, with B. anthina Clade I enriched in genes associated with microbial metabolism in diverse environments, including degradation of aromatic compounds and metabolism of xenobiotics, while B. anthina Clade II demonstrated an enhanced capability for siderophore biosynthesis.

DISCUSSION: Based on our phylogenetic and comparative genomic analyses, we suggest stratifying B. anthina to recognise a distinct species harbouring increased potential for iron metabolism via siderophore synthesis, for which we propose the name Burkholderia anthinoferum (sp. nov.).

PMID:38075871 | PMC:PMC10702961 | DOI:10.3389/fmicb.2023.1274280

ACS Omega. 2023 Nov 25;8(48):45606-45615. doi: 10.1021/acsomega.3c05839. eCollection 2023 Dec 5.

ABSTRACT

Mutations in the unique ATP-binding cassette anion channel, the cystic fibrosis conductance regulator (CFTR), lead to the inherited fatal disease known as cystic fibrosis (CF). Ivacaftor enhances channel gating of CFTR by stabilizing its open state and has been approved as monotherapy for CF patients with CFTR gating mutations (e.g., G551D) and as part of combination therapy with lumacaftor for CFTR folding mutations (e.g., ΔF508). However, in the latter context, ivacaftor may destabilize folding-rescued ΔF508-CFTR and membrane-associated proteins and attenuate lumacaftor pharmacotherapy. Here, we tested the hypothesis that the high lipophilicity of ivacaftor may contribute to this effect. We describe the synthesis of three glutamic acid ivacaftor derivatives with reduced lipophilicity that bear different charges at neutral pH (compounds 2, 3, 4). In a cellular ion flux assay, all three restored G551D-CFTR channel activity at comparable or better levels than ivacaftor. Furthermore, unlike ivacaftor, compound 3 did not attenuate levels of folding-rescued ΔF508 at the cell surface. Molecular modeling predicts that the increased polarity of compound 3 allows engagement with polar amino acids present in the binding pocket with hydrogen bonding and ionic interactions, which are collectively higher in strength as compared to hydrophobic interactions that stabilize ivacaftor. Overall, the data suggests that reduced lipophilicity may improve the efficacy of this class of CFTR potentiators when used for folding-rescued ΔF508-CFTR.

PMID:38075767 | PMC:PMC10702196 | DOI:10.1021/acsomega.3c05839

Front Endocrinol (Lausanne). 2023 Nov 23;14:1269139. doi: 10.3389/fendo.2023.1269139. eCollection 2023.

ABSTRACT

Cystic fibrosis (CF) is a multi-organ disease caused by loss-of-function mutations in CFTR (which encodes the CF transmembrane conductance regulator ion channel). Cystic fibrosis related diabetes (CFRD) occurs in 40-50% of adults with CF and is associated with significantly increased morbidity and mortality. CFRD arises from insufficient insulin release from β cells in the pancreatic islet, but the mechanisms underlying the loss of β cell function remain understudied. Widespread pathological changes in the CF pancreas provide clues to these mechanisms. The exocrine pancreas is the epicenter of pancreas pathology in CF, with ductal pathology being the initiating event. Loss of CFTR function results in ductal plugging and subsequent obliteration. This in turn leads to destruction of acinar cells, fibrosis and fatty replacement. Despite this adverse environment, islets remain relatively well preserved. However, islet composition and arrangement are abnormal, including a modest decrease in β cells and an increase in α, δ and γ cell abundance. The small amount of available data suggest that substantial loss of pancreatic/islet microvasculature, autonomic nerve fibers and intra-islet macrophages occur. Conversely, T-cell infiltration is increased and, in CFRD, islet amyloid deposition is a frequent occurrence. Together, these pathological changes clearly demonstrate that CF is a disease of the pancreas/islet microenvironment. Any or all of these changes are likely to have a dramatic effect on the β cell, which relies on positive signals from all of these neighboring cell types for its normal function and survival. A thorough characterization of the CF pancreas microenvironment is needed to develop better therapies to treat, and ultimately prevent CFRD.

PMID:38075070 | PMC:PMC10704027 | DOI:10.3389/fendo.2023.1269139

Obstet Med. 2023 Dec;16(4):217-221. doi: 10.1177/1753495X221146342. Epub 2022 Dec 25.

ABSTRACT

BACKGROUND: Pregnancy in women with cystic fibrosis (CF) is becoming more common. Long-term metabolic issues such as diabetes are also becoming more common and have potentially important impacts on pregnancy outcomes. This study aimed to assess the impact of diabetes on pregnancy outcomes for women with CF.

METHODS: We undertook a retrospective chart audit of pregnancies to women with CF at the two tertiary obstetric hospitals in Southeast Queensland associated with CF and transplant management clinics between 2006 and 2016.

RESULTS: A total of 38 pregnancies among 26 women were identified. Four women (five pregnancies) had cystic fibrosis-related diabetes (CFRD) diagnosed prior to pregnancy, and 12 women (15 pregnancies) developed gestational diabetes (GDM) complicating pregnancy. CFRD and GDM were associated with higher rates of delivery complications, prematurity, and the need for neonatal intensive care unit admission.

CONCLUSION: Diabetes is common during pregnancy in women with CF and impacts pregnancy outcomes.

PMID:38074210 | PMC:PMC10710202 | DOI:10.1177/1753495X221146342

World J Clin Cases. 2023 Nov 16;11(32):7865-7871. doi: 10.12998/wjcc.v11.i32.7865.

ABSTRACT

BACKGROUND: Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is an uncommon malformation resulting from aberrant development of the portal venous system. Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene. It mainly affects the exocrine glands of the respiratory, digestive and reproductive systems. It is considered extremely rare in the Asian population. We present a clinical case involving a pediatric patient of Asian descent who was diagnosed with Abernethy malformation and CF.

CASE SUMMARY: A 12-year-old girl presented with a medical history of recurring respiratory infections and hemoptysis, and chest computed tomography (CT) showed bronchiectasis. Whole exome sequencing was performed for the patient, yielding findings that revealed a compound heterozygous variant of the CFTR gene: c.233_c.234insT/p.Trp79fsTer3 (maternal origin); c.2909G>A/p.Gly970Asp (paternal origin). CF was diagnosed. The physician's attention was drawn to the presence of splenomegaly during disease progression. Abdominal enhanced CT revealed splenomegaly, compression of the left kidney, and multiple tortuous dilated vascular shadows were seen at the splenic hilum, which flowed back into the left renal vein and portal vein, suggesting Abernethy malformation type II. Intraoperatively, the abnormal blood flow was seen to merge into the inferior vena cava through the left renal vein without hepatic processing, and the pathology of liver biopsy showed hypoplastic, dilated or absent portal vein branches, both of which supported the diagnosis of Abernethy malformation type II. This represents the initial documented instance of Abernethy malformation accompanied by a CFTR gene mutation in the existing body of literature.

CONCLUSION: Coexisting Abernethy malformation and CF are rare. Detailed medical history information, abdominal enhanced CT, venography and genetic testing contribute to diagnosis as well as differential diagnosis.

PMID:38073688 | PMC:PMC10698423 | DOI:10.12998/wjcc.v11.i32.7865

Int Forum Allergy Rhinol. 2023 Dec 11. doi: 10.1002/alr.23309. Online ahead of print.

ABSTRACT

INTRODUCTION: Hypoxia due to sinus obstruction is a major pathogenic mechanism leading to sinusitis. The objective of the current study is to define the electrophysiologic characteristics of hypoxia in vitro and in vivo.

METHODS: Cystic fibrosis bronchoepithelial cells expressing wild-type cystic fibrosis transmembrane conductance regulator (CFTR) and human sinonasal epithelial cells were exposed to 1% or atmospheric O2 for 24 h. Time-dependent production of cytoplasmic free radicals was measured. Cells were subjected to Ussing chamber and patch clamp technique where CFTR currents were recorded in whole-cell and cell-attached mode for single channel studies. Indices of mucociliary transport (MCT) were measured using micro-optical coherence tomography. In a rabbit hypoxic maxillary sinus model, tissue oxygenation, relative mRNA expression of HIF-1α, pH, sinus potential difference (SPD), and MCT were determined.

RESULTS: Ussing chamber (p < 0.05), whole-cell (p < 0.001), and single channel patch-clamp (p < 0.0001) showed significant inhibition of Cl- currents in hypoxic cells. Cytoplasmic free radicals showed time-dependent elevation peaking at 4 h (p < 0.0001). Airway surface liquid (p < 0.0001), periciliary liquid (p < 0.001), and MCT (p < 0.01) were diminished. Co-incubation with the free radical scavenger glutathione negated the impact of hypoxia on single channel currents and MCT markers. In sinusitis rabbits, mucosa exhibited low tissue oxygenation (p < 0.0001), increased HIF1α mRNA (p < 0.05), reduced pH (p < 0.01), and decreased MCT (p < 0.001). SPD measurements demonstrated markedly diminished transepithelial Cl- transport (p < 0.0001).

CONCLUSION: Hypoxia induces severe CFTR dysfunction via free radical production causing reduced MCT in vitro and in vivo. Improved oxygenation is critical to reducing the impact of persistent mucociliary dysfunction.

PMID:38073611 | DOI:10.1002/alr.23309

Physiol Genomics. 2023 Dec 11. doi: 10.1152/physiolgenomics.00077.2023. Online ahead of print.

ABSTRACT

Chronic intestinal inflammation is a poorly understood manifestation of Cystic Fibrosis (CF), which may be refractory to ion channel CFTR modulator therapy. People with CF exhibit intestinal dysbiosis which has potential for stimulating intestinal and systemic inflammation. CFTR is expressed in organ epithelia and in the leukocyte population. Here, we investigate the contribution of intestinal epithelial-specific loss of Cftr (iCftr KO) to dysbiosis and inflammation in mice treated with either of two anti-obstructive dietary regimens necessary to maintain CF mouse models (PEG laxative or a liquid diet, LiqD). Feces collected from iCftr KO mice and their wildtype (WT) sex-matched littermates were used to measure fecal calprotectin and to perform 16S rRNA sequencing to characterize the gut microbiome. Fecal calprotectin was elevated in iCftr KO relative to WT samples of mice consuming either PEG or LiqD. PEG iCftr KO mice did not show a change in a-diversity versus WT but demonstrated a significant difference in microbial composition (b-diversity) with increases in phylum Proteobacteria, family Peptostreptococcaceae, four genera of Clostridia including C. innocuum, and mucolytic genus Akkermansia. Fecal microbiome analysis of LiqD iCftr KO mice showed both decreased a-diversity and differences in microbial composition with increases in Proteobacteria family Enterobacteriaceae, Firmicutes families Clostridiaceae and Peptostreptococcaceae, and enrichment of Clostridium perfringens, C. innocuum, C. difficile, mucolytic Ruminococcus gnavus, and reduction of Akkermansia. It was concluded that epithelial-specific loss of Cftr is a major driver of CF intestinal dysbiosis and inflammation with significant similarities to previous studies of global Cftr KO mice.

PMID:38073491 | DOI:10.1152/physiolgenomics.00077.2023

Dig Liver Dis. 2023 Dec 9:S1590-8658(23)00993-3. doi: 10.1016/j.dld.2023.10.007. Online ahead of print.

ABSTRACT

BACKGROUND: Transition is a crucial process in the care of IBD patients, although it remains largely heterogeneous.

AIMS: To provide an overview of the transition process in Italy and to investigate the perspective of the paediatric and adult physicians.

METHODS: An online survey was developed by the Italian Group for Inflammatory Bowel Diseases (IG-IBD) and the Italian Society of Paediatric Gastroenterology, Hepatology and Nutrition (SIGENP).

RESULTS: 104 physicians (62 paediatric and 42 adult gastroenterologists) participated to the survey. The disease status was ranked with the highest priority among the key elements of the transition process. The age of the patient was perceived with a higher priority by paediatric gastroenterologists than by adult ones (p < 0.01). In most cases, the transition was organized through one or more joint meetings. Only less than 25 % of responders reported to involve other professions during transition. The struggle in leaving paediatric setting was perceived as the main obstacle to an effective transition process. Paediatric IBD gastroenterologists ranked the struggle in leaving the paediatric setting and the attending physician as higher critical point than adult gastroenterologists.

CONCLUSIONS: The current survey provided a snapshot of the IBD transition process in Italy. The present findings highlight the need to embed transitional care in healthcare policy.

PMID:38072745 | DOI:10.1016/j.dld.2023.10.007

Eur J Hosp Pharm. 2023 Dec 9:ejhpharm-2023-003937. doi: 10.1136/ejhpharm-2023-003937. Online ahead of print.

ABSTRACT

BACKGROUND: Inhaled antibiotics have achieved or stabilised the clinical condition of patients with cystic fibrosis (CF) and chronic Pseudomonas aeruginosa infection. We aimed to determine the effectiveness of aztreonam lysine inhaled solution (AZLI) in patients with CF and chronic P. aeruginosa infection.

METHODS: A retrospective observational study was conducted on patients with CF and chronic P. aeruginosa infection who received AZLI between July 2012 and September 2018 inclusive in three Spanish hospitals in a routine clinical practice setting. The primary endpoint was the absolute change in the percentage of predicted forced expiratory volume in 1 second (FEV1) compared with the previous 12 months, at the start of AZLI treatment and 12 months after starting the drug. Other variables analysed were exacerbations, hospitalisations, type and route of antibiotics prescribed, weight and body mass index (BMI) and adverse drug reactions.

RESULTS: In a cohort of 52 patients, AZLI treatment led to stabilisation of FEV1, changing from a mean (SD) value of 55.60 (21.3)% at the start of treatment to 56.8 (20.4)% after 12 months of treatment (p=0.5296) in patients who had not previously received the drug. In addition, it significantly reduced exacerbations from a median (P25; P75) of 2.0 (1.0; 3.0) in the 12 months prior to AZLI to 1.0 (1.0; 2.0) in the 12 months after treatment initiation (p=0.0350). AZLI also reduced the need for other antibiotics and prevented a decrease in BMI, with an adequate safety profile.

CONCLUSIONS: AZLI achieved stabilisation of lung function measured by FEV1 in patients with CF and chronic P. aeruginosa infection, along with an adequate safety profile.

PMID:38071521 | DOI:10.1136/ejhpharm-2023-003937

Cells. 2023 Nov 30;12(23):2741. doi: 10.3390/cells12232741.

ABSTRACT

The ubiquitin E3 ligase UBE3C promotes the proteasomal degradation of cytosolic proteins and endoplasmic reticulum (ER) membrane proteins. UBE3C is proposed to function downstream of the RNF185/MBRL ER-associated degradation (ERAD) branch, contributing to the ERAD of select membrane proteins. Here, we report that UBE3C facilitates the ERAD of misfolded CFTR, even in the absence of both RNF185 and its functional ortholog RNF5 (RNF5/185). Unlike RNF5/185, UBE3C had a limited impact on the ubiquitination of misfolded CFTR. UBE3C knockdown (KD) resulted in an additional increase in the functional ∆F508-CFTR channels on the plasma membrane when combined with the RNF5/185 ablation, particularly in the presence of clinically used CFTR modulators. Interestingly, although UBE3C KD failed to attenuate the ERAD of insig-1, it reduced the ERAD of misfolded ∆Y490-ABCB1 and increased cell surface expression. UBE3C KD also stabilized the mature form of ∆F508-CFTR and increased the cell surface level of T70-CFTR, a class VI CFTR mutant. These results suggest that UBE3C plays a vital role in the ERAD of misfolded CFTR and ABCB1, even within the RNF5/185-independent ERAD pathway, and it may also be involved in maintaining the peripheral quality control of CFTR.

PMID:38067172 | PMC:PMC10706245 | DOI:10.3390/cells12232741

Lancet Respir Med. 2023 Dec 6:S2213-2600(23)00233-3. doi: 10.1016/S2213-2600(23)00233-3. Online ahead of print.

ABSTRACT

Improving the treatment of non-cystic fibrosis bronchiectasis in children and adolescents requires high-quality research with outcomes that meet study objectives and are meaningful for patients and their parents and caregivers. In the absence of systematic reviews or agreement on the health outcomes that should be measured in paediatric bronchiectasis, we established an international, multidisciplinary panel of experts to develop a core outcome set (COS) that incorporates patient and parent perspectives. We undertook a systematic review from which a list of 21 outcomes was constructed; these outcomes were used to inform the development of separate surveys for ranking by parents and patients and by health-care professionals. 562 participants (201 parents and patients from 17 countries, 361 health-care professionals from 58 countries) completed the surveys. Following two consensus meetings, agreement was reached on a ten-item COS with five outcomes that were deemed to be essential: quality of life, symptoms, exacerbation frequency, non-scheduled health-care visits, and hospitalisations. Use of this international consensus-based COS will ensure that studies have consistent, patient-focused outcomes, facilitating research worldwide and, in turn, the development of evidence-based guidelines for improved clinical care and outcomes. Further research is needed to develop validated, accessible measurement instruments for several of the outcomes in this COS.

PMID:38070531 | DOI:10.1016/S2213-2600(23)00233-3

Int J Mol Sci. 2023 Dec 1;24(23):17028. doi: 10.3390/ijms242317028.

ABSTRACT

Pseudomonas aeruginosa is one of the six antimicrobial-resistant pathogens known as "ESKAPE" that represent a global threat to human health and are considered priority targets for the development of novel antimicrobials and alternative therapeutics. The virulence of P. aeruginosa is regulated by a four-chemicals communication system termed quorum sensing (QS), and one main class of QS signals is termed acylhomoserine lactones (acyl-HSLs), which includes 3-Oxo-dodecanoil homoserine lactone (3-Oxo-C12-HSL), which regulates the expression of genes implicated in virulence and biofilm formation. Lactonases, like Paraoxonase 2 (PON2) from humans and the phosphotriesterase-like lactonases (PLLs) from thermostable microorganisms, are able to hydrolyze acyl-HSLs. In this work, we explored in vitro and in an animal model the effect of some lactonases on the production of Pseudomonas virulence factors. This study presents a model of chronic infection in which bacteria were administered by feeding, and Drosophila adults were treated with enzymes and the antibiotic tobramycin, alone or in combination. In vitro, we observed significant effects of lactonases on biofilm formation as well as effects on bacterial motility and the expression of virulence factors. The treatment in vivo by feeding with the lactonase SacPox allowed us to significantly increase the biocidal effect of tobramycin in chronic infection.

PMID:38069351 | DOI:10.3390/ijms242317028