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Verleden, S. E.

Publications and source records attributed to Verleden, S. E..

5 recordsLinked to original sources

Single-cell and spatial transcriptomics resolve airway obliteration in bronchiolitis obliterans syndrome

Background: Chronic lung allograft dysfunction (CLAD) is the leading cause of death beyond the first year after lung transplantation, and its most frequent phenotype is bronchiolitis obliterans syndrome (BOS), a fibrotic small-airway disease. Mechanistic work has focused on the immune compartment, yet intensified immunosuppression does not alter established disease. Aim: To resolve which structural cell states populate the BOS graft and how they are spatially organized during airway obliteration. Methods: We profiled explanted lungs from 33 BOS patients undergoing re-transplantation and 33 controls, combining single-nucleus RNA sequencing (14 BOS, 13 controls) with targeted spatial transcriptomics of 108 regions (27 BOS, 24 controls) and multiplex immunofluorescence validation. Single-nucleus data were integrated with a published restrictive allograft syndrome (RAS) atlas. Results: Across 175,128 nuclei and 1.67 million spatially resolved cells, BOS lungs harbored a profibrotic circuit of Aberrant Basaloid cells and CTHRC1+ fibrotic fibroblasts previously described in fibrotic lung diseases, including RAS. Spatial mapping identified a CXCL14+TNC+ injury-associated basal cell state arising early in the obliterative cascade, identifying basal cells as their major reservoir. CTHRC1+ fibroblasts expanded subepithelially replacing resident peribronchial fibroblasts, alongside a peribronchial vascular shift toward systemic venous endothelium. The circuit extended beyond the airway wall to the alveolar interface, defining two convergent remodeling fronts. Conclusion: BOS engages structural-cell circuits largely shared with RAS and fibrotic lung diseases, but along an airway-centered rather than parenchyma-centered axis. CLAD thus emerges as a spatial rather than cellular spectrum, defined by anatomical distribution more than cell identity. Shared structural programs may therefore be targetable across CLAD phenotypes.

cell biology↗

The Human Organ Atlas

We present the Human Organ Atlas (HOA), an open data repository making accessible multiscale 3D imaging of human organs. The repository also provides software tools and training resources enabling worldwide access, sharing, and analysis of these datasets, facilitating further research and the continued expansion of the HOA. The images are generated using a synchrotron imaging technique - Hierarchical Phase-Contrast Tomography (HiP-CT) that uses the ESRFs Extremely Brilliant Source, spanning whole organ imaging at around 20 m/voxel with local volumes of interest within the intact organs imaged down to [~] 1 m/voxel. This offers a comprehensive exploration of human anatomy, providing unparalleled insights into intricate structures and spatial relationships. The Human Organ Atlas offers researchers, clinicians, and educators a valuable resource for anatomical study, image analysis, medical education, and large-scale data mining.

bioinformatics↗

Preparation of large biological samples for high-resolution, hierarchical, multi-modal imaging

Imaging the different scales of biological tissue is essential for understanding healthy organ behavior and pathophysiological changes. X-ray micro-tomography using both laboratory ({micro}CT) and synchrotron sources (sCT) is a promising tool to image the 3D morphology at the macro- and micro-scale of large samples, including intact human organs. Preparation of large samples for high resolution imaging techniques remains a challenge due to limitations with current methods, such as sample shrinkage, insufficient contrast, movement of the sample and bubble formation during mounting or scanning. Here, we describe a protocol to prepare, stabilize, and image large soft-tissue samples with X-ray microtomography. We demonstrate the protocol using intact human organs and Hierarchical Phase-Contrast Tomography (HiP-CT) imaging at the European Synchrotron Radiation Facility, but the protocol is equally applicable to a range of biological samples, including complete organisms, for both laboratory and synchrotron source tomography. Our protocol enhances the contrast of the sample, while preventing sample motion during the scan, even in case of different sample orientations. Bubbles trapped during mounting and those formed during scanning (in case of synchrotron X-ray imaging) are mitigated by multiple degassing steps. The sample preparation is also compatible with magnetic resonance imaging (MRI), CT, and histological observation. We describe a protocol for sample preparation and mounting which requires 25 to 34 days for a large organ such as an intact human brain or heart. This preparation time varies depending on the composition, size, and fragility of the tissue. Use of the protocol enables scanning of intact organs with a diameter of 150 mm with a local pixel size of one micron using HiP-CT.

physiology↗

A multiscale X-ray phase-contrast tomography dataset of whole human left lung

Technological advancements in X-ray imaging using bright and coherent synchrotron sources now allows to decouple sample size and resolution, while maintaining high sensitivity to the microstructure of soft, partially dehydrated tissues. The recently developed imaging technique, hierarchical phase-contrast tomography, is a comprehensive approach to address the challenge of organ-scale (up to tens of centimeters) soft tissue imaging with resolution and sensitivity down to the cellular level. Using this technique, we imaged ex vivo an entire human left lung at an isotropic voxel size of 25.08 m along with local zooms down to 6.05 - 6.5 m and 2.45 - 2.5 m in voxel size. The high tissue contrast offered by the fourth-generation synchrotron source at the European Synchrotron Radiation Facility reveals complex multiscale anatomical constitution of the human lung from the macroscopic (centimeter) down to the microscopic (micrometer) scale. The dataset provides complete organ-scale 3D information of the secondary pulmonary lobules and delineates the microstructure of lung nodules with unprecedented detail.

physiology↗

The memory of airway epithelium damage in smokers and COPD patients

RationaleChronic obstructive pulmonary disease (COPD) is a devastating and mostly irreversible lung disease. In COPD, the bronchial epithelium displays several structural and functional abnormalities affecting barrier integrity, cell polarity, and differentiation, as well as epithelial-to-mesenchymal transition and inflammation. Although COPD displays mostly irreversible changes, the (ir)reversible nature of epithelium pathology ex vivo remains poorly known and was the aim of this study. MethodsThe persistence of COPD epithelium abnormalities was addressed in long-term (10 weeks) primary cultures of air/liquid interface-reconstituted airway epithelium from non-smoker controls, smoker controls, and COPD patients. Barrier function, epithelial polarity, cell commitment, epithelial-to-mesenchymal transition and inflammation were assessed in vitro, and certain features were compared in situ to the native epithelium. The role of inflammation was explored by stimulating cultures with a cytokine mix consisting of TNF-, IL-6 and IL-1{beta}. Measurements and main resultsAlmost all epithelial defects (barrier dysfunction, impaired polarity, lineage abnormalities) observed in cells from smokers and COPD patients persisted in vitro up to week 10, except IL-8/CXCL-8 release and epithelial-to-mesenchymal transition which declined over time. Cell lineage and polarity impairments matched abnormalities observed in situ in the surgical samples from which the in vitro epithelium was derived. Cytokine treatment induced COPD-like changes and, in COPD cells, reactivated epithelial-to-mesenchymal transition. ConclusionsThe airway epithelium from smokers and COPD patients displays a memory of its native state and previous injuries by cigarette smoking, which is multidimensional and sustained for extended periods of time.

pathology↗