Fig. 7: dsDNA activates the STING pathway in macrophages thereby promoting fibroblast activation via the IL6-STAT3 axis.

a Gene ontology (GO) functional enrichment analysis showed that the enriched DNA damage and repair genes in the BAS group at 24 h after tracheal injury compare to control group (n = 3 mice per group). b Representative images of H&E staining and immunofluorescence of γH2AX(green) in mouse trachea(n = 3 mice per group). Scale bars indicate 50 μm in H&E staining images, 50 μm and 10 μm in immunofluorescence images. c Representative tracheal immunofluorescence images of dsDNA(pink), F4/80(red), P-STING (green), cGAS(yellow) in mouse trachea (n = 3 mice per group). Scale bars indicate 200 μm and 50 μm. d Schematic of use DECS to stimulate BMDMs. e Quantification analysis of dsDNA in cell culture supernatant in control group and DECS group (n = 4 independent experiments). f Representative images of AGAR gel electrophoresis of cell supernatants from control and DECS groups (n = 3 independent experiments). g, h Protein levels of phosphorylated STING in BMDM group stimulated with or without DECS, n = 3 independent experiments. i Schematic of BMDMs from WT mice stimulated by transfection of mouse tracheal DNA by lipo3000. j, k Protein levels of phosphorylated STING in the BMDM group stimulated with or without DNA (n = 3 independent experiments). l Representative immunofluorescence images of P-STING(green) in BMDM, Scale bars indicate 50 μm. m Quantitative analysis of relative Mean fluorescence intensity of P-STING (n = 5 independent experiments). o Protein levels of IL6 in the supernatant of BMDM group stimulated with or without DNA (n = 4 independent experiments). p mRNA levels of IL6 in control group, DNA stimulated group and DNA stimulated group treated with C176 (n = 4 independent experiments). q, r Representative tracheal immunofluorescence images of and quantitative analysis of mean fluorescence intensity of P-STAT3(green) and IL6(red) in the different groups (n = 3 mice per group). Scale bars indicate 200 μm and 20 μm. s Schematic diagram depicting in-vitro co-culture model. t, u Representative immunofluorescence images of and quantitative analysis of mean fluorescence intensity of P-STAT3(red) and αSMA(green) in fibroblasts (n = 3 independent experiments). Scale bars indicate 10 μm. Data are presented as the mean ± SEM. A two-sided student’s T-test was used in (e, h, k, o). One-way ANOVA analysis followed by Tukey post hoc multi-comparison test was used in (m, p, r, u). Source data are provided as a Source Data file.