Session Information
Date: Sunday, November 17, 2024
Title: Systemic Sclerosis & Related Disorders – Basic Science Poster I
Session Type: Poster Session B
Session Time: 10:30AM-12:30PM
Background/Purpose: Investigation of Transcriptional Changes in Interstitial Lung Disease (ILD) and Exploration of Functional Effects of Differential Genes and Expressed Proteins in the Development of ILD.
Methods: This study analyzed ILD patients’ lung tissue transcriptomic datasets using bioinformatics to identify differentially expressed genes. An ILD mouse model was created with bleomycin, and mRNA sequencing compared gene transcription levels between early/late-stage ILD mice and controls. Cross-analysis of human and mouse data identified common genes, with their functions and pathways further analyzed. The expression of SFRP2 in lung tissue, peripheral blood and ILD mice of CTD-ILD patients was detected by multiple techniques. An in vitro EMT model was established using TGF-β1-stimulated A549 cells, with recombinant sFRP2 to assess EMT and Wnt signaling markers, while Wnt inhibitor IWR-1 was used to explore sFRP2-induced EMT mechanisms. Immunofluorescence evaluated EMT-related proteins and sFRP2 in CTD-ILD patients and ILD mice.
Results: 1. Transcriptomic analysis of lung tissues from four ILD patient groups identified 4048, 5317, 4120, and 3337 differentially expressed genes (DEGs) respectively, with 902 showing consistent trends. In ILD model mice, 1810 and 3259 genes were significantly different at early (day 7) and late (day 21) stages compared to controls. Cross-species analysis found 80 consistent DEGs, with SFRP2 notably upregulated, highlighting its pivotal role. Functional enrichment linked SFRP2 to EMT and Wnt signaling pathways.
2. sFRP2 protein levels were significantly higher in CTD-ILD patient blood compared to controls and CTD patients without ILD. In ILD model mice, sFRP2 expression increased significantly by day 7, continued rising by day 14, and peaked by day 21. Immunofluorescence showed SFRP2 overexpression and related protein increases concentrated in alveoli and terminal bronchioles. ILD patient and model tissues also showed upregulated EMT functionality and Wnt signaling, correlating with sFRP2 expression levels.
3. TGF-β1 stimulation of A549 lung epithelial cells revealed low concentrations activated the Wnt pathway, while high concentrations inhibited it. EMT and Wnt were significantly activated at 2.5 μg/ml TGF-β1, forming an in vitro EMT model. Exogenous recombinant sFRP2 at 6nM or 10nM downregulated E-cadherin, upregulated vimentin and α-smooth muscle actin, and promoted β-catenin increase, activating Wnt signaling, while higher sFRP2 concentrations (100nM, 200nM) inhibited these effects. sFRP2-induced changes were antagonized by the Wnt inhibitor IWR-1, reducing fibrosis-related fibronectin production.
Conclusion: 1. The SFRP2 gene is found to be excessively transcribed in the early stages of ILD and maintains high expression throughout the disease progression.
2. The sFRP2 protein can induce EMT in lung epithelial cells by activating the Wnt signaling pathway, thereby participating in the occurrence and development of ILD.
3. Administration of Wnt signaling pathway inhibitors can attenuate the EMT function promoted by sFRP2 protein, indicating its potential as a therapeutic target for alleviating fibrotic lesions of ILD.
To cite this abstract in AMA style:
Wu Y, Li Y, Liu Y. Secreted Frizzled-Related Protein 2 (sFRP2) Regulates Wnt Signaling to Affect Mesenchymal Transition of Lung Epithelial Cells Participates in Interstitial Lung Disease [abstract]. Arthritis Rheumatol. 2024; 76 (suppl 9). https://acrabstracts.org/abstract/secreted-frizzled-related-protein-2-sfrp2-regulates-wnt-signaling-to-affect-mesenchymal-transition-of-lung-epithelial-cells-participates-in-interstitial-lung-disease/. Accessed .« Back to ACR Convergence 2024
ACR Meeting Abstracts - https://acrabstracts.org/abstract/secreted-frizzled-related-protein-2-sfrp2-regulates-wnt-signaling-to-affect-mesenchymal-transition-of-lung-epithelial-cells-participates-in-interstitial-lung-disease/