Cell autonomous TLR4 signaling modulates TGF-β induced activation of human cardiac fibroblasts

Figures

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  Fig. 1. The expression of TLRs in adult cardiac fibroblasts: (A) FACS analysis for TLR4 in human cardiac fibroblasts with unstained control and cardiac fibroblasts stained with anti-TLR4 APC antibody. (B) Western blot and quantitative analysis showing the expression of TLR4 in CF in growth medium with 10 % serum, 2 % serum and with LPS stimulation.(C) Dot plot representing the expression of different TLRs in human cardiac fibroblast clusters. (D) Dot plot representing the average expression and percentage cells expressing different Tlr genes in healthy mouse adult Col1-GFP labelled cardiac fibroblasts by single-cell RNA seq data. (E) Temporal changes in gene expression of Tlr4 following cardiac injury: UMAP demonstrating the expression of Tlr4 in Col1-GFP single-cell RNA seq data of healthy and at different time points at 7 days, 14 days, and 30 days following injury. (F) Dot plot demonstrating the expression of Tlr4, Myd88, Tril, Traf6, Tab2, Mapk14, Nfkb1, and Jun in healthy control and injured Col1-GFP labelled cardiac fibroblasts at 7 days, 14 days and 30 days post-injury by single-cell sequencing (n = 3).

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  Fig. 2. Expression of genes encoding cytokines: (A) Expression of cytokines and related genes in mouse Col1-GFP cardiac fibroblasts in healthy control and on different days following injury. (B) Expression of cytokines and related genes in human cardiac fibroblast clusters of healthy and heart failure patients' sample. (C) Expression of cytokines in human cardiac fibroblasts in basal conditions in vitro.

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  Fig. 3. Inhibiting TLR4 signaling reduces differentiation and migration of myofibroblasts: (A) qPCR showing the expression of fibrotic genes, Collagen1A1 and α-Sma in cardiac fibroblasts treated with TGF-β, n = 8. (B) qPCR showing the expression of fibrotic markers Collagen1A1 and α-Sma in TGF-β plus TAK-242 treated cells compared to TGF-β with vehicle alone control,n = 5.(C) Scratch wound assay to determine the migration of cardiac fibroblasts in the presence of TGF−β plus TAK-242, TGF-β alone and controls cells in medium with 10 % FBS and 2 % FBS. (D) Percentage area of cardiac fibroblast migration in TGF-β condition versus TGF-β plus TAK-242 treatment and controls,n = 4. (E) Cardiac fibroblasts seeded on contractable collagen gel matrices were assayed for gel contraction after treatment with TGF-β and TGF-β plus TAK-242 for 24 h, n = 4. Data are represented as the mean ± SE, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.0001, ns = p > 0.05.

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  Fig. 4. Inhibiting TLR4 signaling reduces the expression of extracellular matrix genes: (A) GO enrichment analysis to determine the biological processess that are significantly altered with TGF-β treatment (for 48 h) in cardiac fibroblasts compared to control cells without TGF-β. (B) GO enrichment analysis to determine the biological processess significantly inhibited by TAK-242 in TGF-β treated cardiac fibroblasts. (C) Heatmap showing the scaled expression of extracellular matrix genes with TAK-242 treatment. (D) Expression of genes encoding profibrotic factors and extracellular matrix by qPCR in TGF-β+TAK-242 compared to TGF-β only, n = 4. Data are represented as the mean ± SE, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.0001.

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  Fig. 5. Protein-protein interaction network analysis: (A) Protein-protein interaction network of cells treated with TAK-242 with TGFβ compared to TGFβ alone. (B) Top 20 hub genes identified using cytohubba in Cytoscape. (C) qPCR showing the fold increase in IL6 expression with TGFβ treatment in cardiac fibroblasts in vitro,n = 6,p < 0.05.