Biology subjects

Duerr, J.

Publications and source records attributed to Duerr, J..

7 recordsLinked to original sources

bioRxiv2024

Systemic effects of cystic fibrosis transmembrane conductance regulator (CFTR) modulators on the blood proteome

Cystic fibrosis (CF), resulting from a dysfunction in the cystic fibrosis transmembrane conductance regulator (CFTR), affects multiple organs through mucus obstruction and differences in secretion. The CFTR modulator drug combination elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA, ETI) has markedly improved clinical symptoms, but its broader molecular and systemic effects remain to be fully elucidated. We employed mass spectrometry-based proteomics to compare the blood proteomes of CF patients treated with the earlier, less effective lumacaftor/ivacaftor (LUM/IVA) combination against those receiving the more potent ELX/TEZ/IVA therapy. Our analysis revealed both specific and common pharmacodynamic signatures associated with inflammation and metabolic processes under each treatment regimen. Notably, ELX/TEZ/IVA therapy exhibited more consistent alterations across patients that were directed towards profiles observed in healthy individuals. Furthermore, by comparing sputum and blood proteomes of ELX/TEZ/IVA treated patients we identified counter-directional changes in the pulmonary surfactant-associated protein B, SFTPB, a potential biomarker of lung tissue repair, which also correlated with lung function improvements. This study provides a comprehensive resource that enhances our understanding of CFTR modulator-driven proteome alterations, offering insights to both systemic and local protein regulation in CF. Our findings indicate that ELX/TEZ/IVA promotes broader systemic health improvements, providing critical insights that could shape future therapeutic strategies in CF.

molecular biology↗

bioRxiv2024

Functional lung imaging identifies peripheral ventilation changes in mice with muco-obstructive lung disease

{beta}-ENaC-Tg mice serve as a relevant model of muco-obstructive lung disease, with impaired mucociliary clearance, mucus obstruction, chronic airway inflammation, structural lung damage, and altered lung function. The aim of this study was to undertake a comprehensive lung function and mechanics analysis of the adult {beta}-ENaC-Tg model. {beta}-ENaC-Tg and wild-type littermates underwent X-ray Velocimetry (XV) scans using a Permetium XV scanner (4DMedical, Melbourne, Australia). For comparative lung mechanics, lung function assessments were conducted with a flexiVent system. XV imaging demonstrated elevated ventilation defect percentage, mean specific ventilation, and ventilation heterogeneity in {beta}-ENaC-Tg mice. Spatial analysis of ventilation maps indicated increased ventilation variability in the peripheral lung regions, as well as an increased proportion of under-ventilated areas. The flexiVent analysis indicated that compared to wild-types, {beta}-ENaC-Tg mice have a significantly more compliant lungs with increased inspiratory capacity, reduced tissue elastance and increased hysteresivity (heterogeneity), suggesting loss of parenchymal integrity. This research highlights the utility of XV imaging in evaluating ventilation defects in the {beta}-ENaC-Tg model and provides a comprehensive lung function analysis.

physiology↗

bioRxiv2024

Reflection confocal microscopy for quantitative assessment of airway surface liquid dysregulation and pharmacological rescue in cystic fibrosis under near-physiological conditions

Proper regulation of airway surface liquid (ASL) is essential for effective mucociliary clearance (MCC) in healthy airways, and ASL depletion due to deficient cystic fibrosis transmembrane conductance regulator (CFTR)-mediated anion/fluid secretion plays an important role in the pathogenesis of mucociliary dysfunction and chronic muco-obstructive lung disease in patients with cystic fibrosis (CF). The current standard for quantitative measurements of ASL height is confocal fluorescence microscopy that has the disadvantage that it requires apical addition of volume for fluorescent staining, and hence perturbation of the ASL. Therefore, our aim was to develop a method that enables studies of ASL regulation under unperturbed conditions using reflected light by confocal microscopy of primary airway epithelial cultures grown at air-liquid interface (ALI). After apical volume addition to primary tracheal mouse cultures, confocal reflection microscopy yielded comparable ASL height as confocal fluorescence microscopy on cultures of wild-type mice, and was sensitive to detect ASL depletion on cultures of {beta}ENaC-Tg mice. Under unperturbed conditions, ASL determined by confocal reflection microscopy was significantly higher in wild-type and {beta}ENaC-Tg mice compared to values obtained by confocal fluorescence microscopy. Studies in normal and CF primary human airway epithelial cultures showed that confocal reflection microscopy was sensitive to detect effects of low temperature rescue and pharmacological modulation including improvement of CFTR function by VX-809 and VX-770 in cultures from CF patients with the F508del mutation. Our results support confocal reflection microscopy as a novel sensitive technique for quantitative studies of ASL regulation and response to therapeutic intervention under unperturbed near-physiological conditions in healthy and CF airways. NEW & NOTEWORTHYMeasurement of airway surface liquid (ASL) height by confocal fluorescence microscopy is an important tool to investigate ASL dysregulation and effects of therapeutic strategies aiming at restoring ASL volume to improve mucociliary clearance and lung function in patients with cystic fibrosis. However, confocal fluorescence microscopy has the disadvantage that it requires apical addition of volume for fluorescent staining of the ASL leading to perturbation of its height and composition. Here, we developed confocal reflection microscopy as a new method that enables quantitative assessment of ASL on highly-differentiated primary airway epithelial cultures under unperturbed near-physiological conditions by detection of refracted light.

cell biology↗

bioRxiv2024

Ileal mucus viscoelastic properties differ in Crohns disease

Crohns disease (CD) is an inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract, frequently involving the terminal ileum. While colonic mucus alterations in CD patients have been described, terminal ileal mucus and its mechanobiological properties have been neglected. Our study is the first of its kind to decipher the viscoelastic and network properties of ileal mucus. With that aim, oscillatory rheological shear measurements based on an airway mucus protocol that was thoroughly validated for ileal mucus were performed. Our pilot study analyzed terminal ileum mucus from controls (n=11) and CD patients (n=11). Mucus network structure was visualized by scanning electron microscopy (SEM). Interestingly, a statistically significant increase in viscoelasticity as well as a decrease in mesh size was observed in ileal mucus from CD patients compared to controls. Furthermore, rheological data were analyzed in relation to study participants clinical characteristics, such as inflammatory status, revealing noteworthy trends. In conclusion, this study provides the first data on the viscoelastic properties and structure of human ileal mucus in the healthy state and in CD, demonstrating significant alterations between groups and highlighting the need for further research on mucus and its effect on the underlying epithelial barrier.

biophysics↗

bioRxiv2023

Longitudinal Micro-Computed Tomography Detects Onset and Progression of Pulmonary Fibrosis in Conditional Nedd4-2 Deficient Mice

ObjectivesIdiopathic pulmonary fibrosis (IPF) is a fatal lung disease which is usually diagnosed late in advanced stages. Little is known about the subclinical development of IPF. We previously generated a mouse model with conditional Nedd4-2 deficiency (Nedd4-2-/-) that develops IPF-like lung disease. The aim of this study was to characterize the onset and progression of IPF-like lung disease in conditional Nedd4-2-/- mice by longitudinal micro- computed tomography (CT). MethodsIn vivo micro-CT was performed longitudinally in control and conditional Nedd4- 2-/- mice at 1, 2, 3, 4 and 5 months after doxycycline induction. Further, terminal in vivo micro-CT followed by pulmonary function testing and post mortem micro-CT was performed in age-matched mice. Micro-CT images were evaluated for pulmonary fibrosis using an adapted fibrosis scoring system. ResultsMicro-CT is sensitive to detect onset and progression of pulmonary fibrosis in vivo and to quantify distinct radiological IPF-like features along disease development in conditional Nedd4-2-/- mice. Nonspecific interstitial alterations were detected from 3 months, whereas key features such as honeycombing-like lesions were detected from 4 months onwards. Pulmonary function inversely correlated with in vivo (r=-0.725) and post mortem (r=-0.535) micro-CT fibrosis scores. ConclusionLongitudinal micro-CT enables in vivo monitoring of onset and progression and detects radiologic key features of IPF-like lung disease in conditional Nedd4-2-/- mice. Our data support micro-CT as sensitive quantitative endpoint for preclinical evaluation of novel antifibrotic strategies. NEW & NOTEWORTHYIPF diagnosis, particularly in early stages, remains challenging. In this study micro-CT is used in conditional Nedd4-2-/- mice to closely monitor the onset and progression of IPF-like lung disease. This allowed us to track for the first time how nonspecific lung lesions develop into key IPF-like features. This approach offers a non-invasive method to monitor pulmonary fibrosis in vivo, providing a quantitative endpoint for preclinical evaluation of novel antifibrotic strategies.

pathology↗

bioRxiv2023

Dextromethorphan inhibits collagen transport in the endoplasmic reticulum eliciting an anti-fibrotic response in ex-vivo and in vitro models of pulmonary fibrosis

Excessive deposition of fibrillar collagen in the interstitial extracellular matrix (ECM) of human lung tissue causes fibrosis, which can ultimately lead to organ failure. Despite our understanding of the molecular mechanisms underlying the disease, a cure for pulmonary fibrosis has not yet been found. In this study, we screened an FDA-approved drug library containing 712 drugs and found that Dextromethorphan (DXM), a cough expectorant, significantly reduces the amount of excess fibrillar collagen deposited in the ECM in in-vitro cultured primary human lung fibroblasts (NHLF) and ex-vivo cultured human precision-cut lung slice (hPCLS) models of lung fibrosis. Reduced extracellular fibrillar collagen levels in the ECM upon DXM treatment are due to a reversible trafficking inhibition of collagen type I (COL1) in the endoplasmic reticulum (ER) in TANGO1 and HSP47 positive structures. Mass spectrometric analysis shows that DXM causes hyper-hydroxylation of proline and lysine residues on Collagen (COL1, COL3, COL4, COL5, COL7, COL12) and Latent-transforming growth factor beta-binding protein (LTBP1 and LTBP2) peptides coinciding with their secretion block. In addition, thermal proteome profiling of cells treated with DXM shows increased thermal stability of prolyl-hydroxylases such as P3H2, P3H3, P3H4, P4HA1 and P4HA2, suggesting a change in activity. Transcriptome analysis of pro-fibrotic stimulated NHLFs and hPCLS upon DXM treatment showed activation of an anti-fibrotic program via regulation of pathways such as those involved in the MMP-ADAMTS axis, WNT, and fibroblast-to-myofibroblast differentiation. Taken together, the data obtained from both in-vitro and ex-vivo models of fibrogenesis show that Dextromethorphan has potent anti-fibrotic activity by efficient inhibition of COL1 membrane trafficking in the ER.

cell biology↗

bioRxiv2018

Light dynamically regulates growth rate and cellular organisation of the Arabidopsis root meristem.

1Large-scale methods and robust algorithms are needed for a quantitative analysis of cells status/geometry in situ. It allows the understanding the cellular mechanisms that direct organ growth in response to internal and environmental cues. Using advanced whole-stack imaging in combination with pattern analysis, we have developed a new approach to investigate root zonation under different dark/light conditions. This method is based on the determination of 3 different parameters: cell length, cell volume and cell proliferation on the cell-layer level. This method allowed to build a precise quantitative 3D cell atlas of the Arabidopsis root tip. Using this approach we showed that the meristematic (proliferation) zone length differs between cell layers. Considering only the rapid increase of cortex cell length to determine the meristematic zone overestimates of the proliferation zone for epidermis/cortex and underestimates it for pericycle. The use of cell volume instead of cell length to define the meristematic zone correlates better with cell proliferation zone.

plant biology↗