Fibroblast-derived extracellular vesicles contain SFRP1 and mediate pulmonary fibrosis
Olivier Burgy, … , Gerald Burgstaller, Melanie Königshoff
Olivier Burgy, … , Gerald Burgstaller, Melanie Königshoff
Published September 24, 2024
Citation Information: JCI Insight. 2024;9(18):e168889. https://doi.org/10.1172/jci.insight.168889.
View: Text | PDF
Research Article Cell biology Pulmonology

Fibroblast-derived extracellular vesicles contain SFRP1 and mediate pulmonary fibrosis

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

×

Figure 3

Fibroblasts are a major source of EVs during fibrosis.

Options: View larger image (or click on image) Download as PowerPoint
Fibroblasts are a major source of EVs during fibrosis. (A) Venn diagram ...
(A) Venn diagram depicting the cellular origin of the bleomycin BALF-EV proteins. (B and C) Scoring of an scRNA-Seq dataset (GSE141259) for the mean expression of the 107 proteins identified in the bleomycin BALF-EVs in the main cellular compartments of the lung (B) as well as in mesenchymal populations (C). Box plots show the interquartile range, median (line), and minimum and maximum (whiskers). SMCs, smooth muscle cells. (D) Top proteins expressed in fibroblasts, among the proteins identified in bleomycin-BALF-EV and classified in main mesenchymal cellular compartments. (E) Statistical difference in the proteomic dataset between fibrotic and control EVs for the top 3 most expressed fibroblast-related genes. (F) Analysis of an scRNA-Seq dataset (GSE40151) for the expression of EV machinery in fibroblasts expressing (true) or not expressing (false) Sfrp1. (G) Gene expression of Sfrp1 in the lungs of mice with bleomycin-induced lung fibrosis or control (NaCl) mice. Data from GSE40151. (H and I) Expression of SFRP1 in lung tissue from mice exposed to bleomycin at different time points at the transcriptomic (H, data from GSE141259) or proteomic level (I). (J) Immunofluorescence staining for α-SMA (green) and SFRP1 (red) in FFPE lung sections from mice challenged with bleomycin (day 14) or NaCl as control. Representative observation of a fibrotic area from a mouse lung 14 days after bleomycin (right panels). Asterisks denote SFRP1+ transitional fibroblasts, dashed lines indicate fibrotic dense areas with α-SMA+ myofibroblasts (in green), and arrowheads point out single SFRP1+ transitional fibroblasts (in red) in the zoomed ROI. Nuclei are stained with DAPI (blue). Scale bars = 100 μm or 20 μm (ROI’s zoom). (K) Western blot for SFRP1 expression on normal and fibrotic EVs (n = 4/group). Equal number of vesicles (2 × 108) loaded. ALIX serves as EV-enriched protein. Molecular weights (kDa) are indicated. All statistical analyses by nonparametric Mann-Whitney. P values as indicated.