Journal: bioRxiv
Article Title: An FGF7-FGFR2-KLF4 feedback loop sustains anti-inflammatory signaling in epithelial cells
doi: 10.64898/2026.03.20.711763
Figure Lengend Snippet: A) Volcano plots showing KLF4 affinity purification-mass spectrometry (KLF4 AP-MS) data from serum-starved HaCaT keratinocytes treated with FGF7 for 6 h or vehicle vs . the respective IgG control. Enriched prey proteins are located in the upper right quadrant, with KLF4 highlighted (N = 3, one-sided Student’s t -test, FDR<0-05). B) Volcano plot depicting FGF7-dependent changes in KLF4-associated proteins (KLF4 AP-MS data) under the same experimental conditions. p < 0.05 (two-sided Student’s t -test), filtering threshold ≥3 unique tryptic peptides per protein. C) Proteins, which also showed a significantly different abundance in the KLF4 interactome upon FGF7 treatment in an independent experiment. D) Schematic representation of the luciferase reporter vector harboring 4 KLF4 binding sites in the promoter. E) Luciferase activity in lysates of serum-starved HaCaT keratinocytes, stably transduced with lentiviruses including a luciferase reporter gene preceded by KLF4 response elements. Cells were treated for 8, 16 or 24 h with FGF7 or vehicle (N = 6). F) Luciferase activity in lysates of HaCaT keratinocytes, stably transduced with lentiviruses containing a luciferase reporter gene preceded by KLF4 response elements. Cells had been serum-starved and pre-treated for 2 h with the MEK1/2 inhibitor U0126 or vehicle, followed by a 6 h treatment with FGF7 or vehicle (N = 6). G) IL6 promoter cloning strategy showing the deletion of two KLF4 binding sites (BS) and the insertion of the IL6 promoter fragment into the firefly luciferase lentiviral vector. H) Luciferase activity in lysates of HaCaT keratinocytes, stably transduced with lentiviruses containing the IL6 promoter fragment with or without KLF4 BS in front of a luciferase gene. Cells were serum-starved and treated for 6 h with FGF7 or vehicle (N = 6). I) Luciferase activity in lysates of serum-starved HaCaT keratinocytes, stably transduced with lentiviruses containing the IL6 promoter fragment with or without KLF4 BS in front of a luciferase gene. Cells had been serum-starved and pre-treated for 3 h with FGF7 or vehicle and incubated for 6 h with poly(I:C), TNFα, or vehicle (N = 6). Data information: Graphs show mean and SD. Non-significant (ns), *P < 0.05, **P < 0.01; ***P < 0.001; ****P < 0.0001 (Mann-Whitney U test (D, G; normalized to respective control), or 2-way ANOVA with Bonferroni’s multiple comparisons test (E; H).
Article Snippet: The beads were resuspended in 80 μl binding buffer, to which 9.21 μg of KLF4 antibody (Cell Signaling) or 9.21 μg of rabbit control IgG antibody (Merck, Darmstadt, Germany) was added.
Techniques: Affinity Purification, Mass Spectrometry, Protein-Protein interactions, Control, Luciferase, Plasmid Preparation, Binding Assay, Activity Assay, Stable Transfection, Transduction, Cloning, Incubation, MANN-WHITNEY