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Biology subjects

Szmul, A.

Publications and source records attributed to Szmul, A..

4 recordsLinked to original sources

Multiscale mapping of venous remodelling in idiopathic pulmonary fibrosis

The integrity of the pulmonary vasculature is a key determinant of lung health, yet challenges in visualisation and quantification have hindered interrogation of its pathophysiological role in chronic lung disease. Here, we align recent advances in microscale image acquisition with novel computer vision-based vessel segmentation models to demonstrate expansion of the bronchial and pulmonary veins across varying severities of tissue remodelling in idiopathic pulmonary fibrosis (IPF). Relating these imaging findings to molecular data in control, mild, and severe fibrosis, we show that bronchial venous endothelial cells expand beyond their physiological peribronchial niche even in mild disease, acquiring persistent angiogenic, inflammatory, and matrix-remodelling programmes that define a specialised fibrovascular-immune interface. Finally, we relate these microscale and molecular observations to clinical CT imaging, demonstrating that intrapulmonary vein enlargement independently associates with worsened survival across three IPF cohorts. Collectively, our multimodal, multiscale approach connects previously unresolved three-dimensional venous architecture to its molecular endothelial correlate, establishing venous enlargement as a prognostically significant and clinically relevant feature of IPF. Our analytical approach also demonstrates how biological discoveries made in intact ex vivo human organs can translate into measurable phenotypes in living patients, providing a template for other organs and diseases.

pathology↗

BigHeart: Mapping connectivity in the adult human heart at the micron scale

The human heart depends on coordinated muscular, electrical, vascular, lymphatic, and neural systems, but their three-dimensional relationships remain unresolved at microscopic resolution across an intact adult organ. Using hierarchical phase-contrast tomography, we generated a continuous three-dimensional structural reference of a whole adult human heart at 8.01 micrometer isotropic voxel size, without sectioning or staining. Organ-wide imaging revealed hierarchical myocardial architecture, and quantitative orientation analysis identified regional differences in myocardial cell aggregate organization. The atrioventricular conduction axis was traced into a distinct subendocardial Purkinje network interfacing with working myocardium. Integrated segmentation showed that coronary vessels, lymphatic collectors, and autonomic nerves occupy shared epicardial corridors. This publicly accessible dataset integrates cardiac systems within a common spatial framework for anatomy, computational modeling, and future molecular atlases.

physiology↗

Neuroanatomy of the clitoris

The clitoris is one of the least studied organs of the human body. The detailed anatomy of the clitoris is challenging to address through a gross dissection, as most of its parts are embedded internally, surrounded by pubic bone and several pelvic organs. While clinical imaging methods such as magnetic resonance imaging can capture the gross 3D morphology, they lack the spatial resolution required to resolve the detailed structures. In this study, we generated micron-scale computed tomography images of the female pelvises, leveraging a synchrotron radiation X-ray source. This unique data revealed the complex trajectory of the dorsal nerve of the clitoris, the main sensory nerve of the clitoris. Notably, the nerve trunks within the clitoral glans were revealed, with the maximum diameter ranging from 0.2 to 0.7 mm. They showed a tree-like branching pattern projecting towards the surface of the glans. We also revealed that some branches of the dorsal nerve of the clitoris ramify to innervate the clitoral hood and mons pubis. Finally, the posterior labial nerve, a branch of the perineal nerves, was shown to innervate the surroundings of the clitoris and the labial structures. These findings have an immediate impact on operations performed around the vulva area, such as gender-affirmation surgery and reconstruction surgery after genital mutilation.

neuroscience↗

The pleuroparenchymal fibroelastosis atlas reveals aberrant cell states and their zonation as an alternate roadmap to lung fibrosis

BackgroundPleuroparenchymal fibroelastosis (PPFE) is a progressive interstitial lung disease with higher prevalence in females, histologically characterized by intra-alveolar fibrosis with septal elastosis (AFE). Effective treatments are lacking, highlighting the need to dissect its pathogenesis at single-cell resolution. MethodsWe performed single-nucleus RNA sequencing (snRNAseq) on explanted lungs from a German (n=23) and a French cohort (n=17) of PPFE patients, and controls (n=16). Identified cell populations were localized by immunofluorescence and multiplex RNA in-situ hybridization. Hierarchical phase-contrast computed tomography (HiP-CT) and micro-CT provided 3D spatial context. Reanalyzed snRNAseq data from a Belgian IPF cohort (n=9) served as disease comparator. FindingsWe present the first snRNAseq atlas of PPFEs cellular and structural landscape based on a European multinational cohort. 24 PPFE patients were female (60.0%), while 34 were non-smokers (85.0%). 519,920 nuclear transcriptomes from PPFE and IPF patients, and controls were profiled. We identified PPFE-specific accumulations of MFAP5+PI16+SFRP2+ adventitial and LEPR+ITGA8+SFRP2+DIO2+ elastofibrotic fibroblasts as main drivers of elastotic remodeling in PPFE. Multiple PPFE fibroblast subsets acquire an inflammatory activation state as highlighted by the expression of CXCL12 and CXCL14. This is accompanied by a marked increase in lymphocytes and the formation of tertiary lymphoid structures (TLS) in a disease that was previously considered to be purely elastofibrotic. We identified CTHRC1+ fibrotic fibroblasts and Aberrant Basaloid cells in PPFE as well, forming the "Usual Fibrotic Niche". 3D reconstruction of the pronounced COL15A1+ vascular conglomerate at the border of the elastofibrotic and subpleural fibrosis indicates communication with interlobar veins. Last, we observed a zonation of the PPFE lesion, constructed by the above-mentioned PPFE-associated cell types. InterpretationOur unprecedented cellular and molecular survey uncovers previously unobserved PPFE-specific inflammatory and elastogenic fibroblast populations, as well as the presence of CTHRC1+ fibroblasts and Aberrant Basaloid cells common to other fibrotic ILDs. These findings provide the foundation for including PPFE patients in current antifibrotic trials, as well as development of PPFE-specific therapies. FundingSupported mainly by the Else Kroner-Fresenius Foundation, the German Center for Lung Research and the Fondation du Souffle.

cell biology↗