Abstract
Idiopathic pulmonary fibrosis (IPF) is a lethal chronic lung disease characterized by aberrant intercellular communication, extracellular matrix deposition, and destruction of functional lung tissue. While extracellular vesicles (EVs) accumulate in the IPF lung, their cargo and biological effects remain unclear. We interrogated the proteome of EV and non-EV fractions during pulmonary fibrosis and characterized their contribution to fibrosis. EVs accumulated 14 days after bleomycin challenge, correlating with decreased lung function and initiated fibrogenesis in healthy precision-cut lung slices. Label-free proteomics of bronchoalveolar lavage fluid EVs (BALF-EVs) collected from mice challenged with bleomycin or control identified 107 proteins enriched in fibrotic vesicles. Multiomic analysis revealed fibroblasts as a major cellular source of BALF-EV cargo, which was enriched in secreted frizzled related protein 1 (SFRP1). Sfrp1 deficiency inhibited the activity of fibroblast-derived EVs to potentiate lung fibrosis in vivo. SFRP1 led to increased transitional cell markers, such as keratin 8, and WNT/β-catenin signaling in primary alveolar type 2 cells. SFRP1 was expressed within the IPF lung and localized at the surface of EVs from patient-derived fibroblasts and BALF. Our work reveals altered EV protein cargo in fibrotic EVs promoting fibrogenesis and identifies fibroblast-derived vesicular SFRP1 as a fibrotic mediator and potential therapeutic target for IPF.
Authors
Olivier Burgy, Christoph H. Mayr, Déborah Schenesse, Efthymios Fousekis Papakonstantinou, Beatriz Ballester, Arunima Sengupta, Yixin She, Qianjiang Hu, Maria Camila Melo-Narvaéz, Eshita Jain, Jeanine C. Pestoni, Molly Mozurak, Adriana Estrada-Bernal, Ugochi Onwuka, Christina Coughlan, Tanyalak Parimon, Peter Chen, Thomas Heimerl, Gert Bange, Bernd T. Schmeck, Michael Lindner, Anne Hilgendorff, Clemens Ruppert, Andreas Güenther, Matthias Mann, Ali Önder Yildirim, Oliver Eickelberg, Anna Lena Jung, Herbert B. Schiller, Mareike Lehmann, Gerald Burgstaller, Melanie Königshoff
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