Fig 2: IL-11 and IL-11 + sIL-11Rα activate Müller cells in vivo. (A) Representative images of retinal cryosections of C57BL/6J mice 12 h after injection with IL-11, IL-11+sIL-11Rα or PBS control at OIR P12. Scale bar: 25 μm. (B) Representative higher magnification images of the ganglion cell layer, inner plexiform layer and inner nuclear layer after injection with IL-11 or IL-11+sIL-11Rα for better visualization of pSTAT3 Tyr705 and Isolectin co-staining. Scale bar: 25 μm. (C) Representative images retinal cryosections and of higher magnification images of C57BL/6J mice for GFAP 12 h after injection with IL-11, IL-11+sIL-11Rα or PBS control at OIR P12. Scale bar: 25 μm. (D) Representative images of retinal cryosections of ALDH1L1-GFP+ transgenic mice 12 h after injection with IL-11, IL-11+sIL-11Rα or PBS control at OIR P12. GCL = ganglion cell layer, IPL = inner plexiform layer, INL = inner nuclear layer, OPL = outer plexiform layer, ONL = outer nuclear layer. Scale bar: 25 μm

Fig 3: Characterization of angiogenic effects and compensatory changes of signaling pathways after STAT1 knockdown. (A) Spheroid sprouting assay using HUVECs: Cells transfected with control siRNA or STAT1 siRNA were treated under following conditions: EBM (negative control), IL-11, VEGF (positive control), IL-11+VEGF. RSL = Relative Sprouting Length. N = 4 independent experiments each consisting of 14-22 spheroids per group and experiment, statistical testing: Kruskal-Wallis Test adjusted for multiple testing, *p<0.05. Scale bar 20 µM. (B) Spheroid sprouting assay using HUVECs: Cells transfected with control siRNA or STAT1 siRNA were treated under following conditions: EBM (negative control), IL-11+sIL-11Rα, VEGF (positive control), IL-11+sIL-11Rα+VEGF. RSL = Relative Sprouting Length. N = 3 independent experiments each consisting of 11-20 spheroids per group and experiment, statistical testing: Kruskal-Wallis Test adjusted for multiple testing, *p<0.01. Scale bar 20 µM. (C) Semi-quantitative Western blot analysis of signaling molecules in HUVECs after STAT1 knockdown and treatment under the conditions mentioned in (A) for 15 min. Interleaved box and whiskers: the whiskers represent the minimum and maximum values while the line in between represents the median value. N = 3 independent experiments. (D) Semi-quantitative Western blot analysis of signaling molecules in HUVECs after STAT1 knockdown and treatment under the conditions mentioned in (B) for 15 min. Interleaved box and whiskers: the whiskers represent the minimum and maximum values while the line in between represents the median value. N = 3 independent experiments

Fig 4: Analysis of IL-11-mediated signalling in prostate cancer cell lines. A Random forest analysis indicating the error rate as a function of the number of trees, with key genes labelled for their variable importance in the model. B Gene set enrichment analysis (GSEA) showing the running enrichment scores for selected hallmark gene sets across a ranked list of genes from the dataset. The JAK/STAT signalling pathway is emphasized, indicating its involvement in the response to IL-11. C Network representation of the protein‒protein interaction (PPI) focused on IL-11, with edge colours representing the type of interaction and node size correlating with the number of interactions per protein. D Bar graph illustrating the fold change in expression levels of JAK family kinases (JAK1, JAK2, JAK3, TYK3) upon alterations in IL-11 in prostate cancer cell lines. E Bar graph representing the fold change in expression levels of STAT family proteins (STAT1, STAT2, STAT3, STAT4, STAT5A, STAT5B, STAT6) upon alteration of IL-11 in the same cell lines. F Western blot analysis showing protein expression of IL-11 and IL-11RA and the phosphorylation status of JAK1 and STAT4 in response to IL-11 treatment across different prostate cancer cell lines (PC3, DU145, LNCAP, 22RV1). G: Western blot analysis comparing protein expression and phosphorylation of JAK1 and STAT4 upon neutralization of IL-11 or IL-11 antagonist in PC3 and DU145 cell lines

Fig 5: Angiogenic effects and altered signaling patterns of IL-11 cis- and trans-signaling following STAT3 knockdown. (A) Spheroid sprouting assay using HUVECs: Cells transfected with control siRNA or STAT3 siRNA were treated under following conditions: EBM (negative control), IL-11, VEGF (positive control), IL-11 + VEGF. RSL = Relative Sprouting Length. N = 4 independent experiments each consisting of 12-23 spheroids per group and experiment, statistical testing: Kruskal-Wallis Test adjusted for multiple testing, *p<0.05. (B) Spheroid sprouting assay using HUVECs: Cells transfected with control siRNA or STAT3 siRNA were treated under following conditions: EBM (negative control), IL-11 + sIL-11Rα, VEGF (positive control), IL-11 + sIL-11Rα + VEGF. RSL = Relative Sprouting Length. N = 4 independent experiments each consisting of 9-22 spheroids per group and experiment, statistical testing: Kruskal-Wallis Test adjusted for multiple testing, *p<0.01. (C) Semi-quantitative Western blot analysis of signaling molecules in HUVECs after STAT3 knockdown and treatment under the conditions mentioned in (A) for 15 min. Interleaved box and whiskers: the whiskers represent the minimum and maximum values while the line in between represents the median value. N = 3 independent experiments. (D) Semi-quantitative Western blot analysis of signaling molecules in HUVECs after STAT3 knockdown and treatment under the conditions mentioned in (B) for 15 min. Interleaved box and whiskers: the whiskers represent the minimum and maximum values while the line in between represents the median value. N = 3 independent experiments