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Biology subjects

Dettmer, S.

Publications and source records attributed to Dettmer, S..

3 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↗

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 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↗