Journal: bioRxiv
Article Title: Fibroblasts sense spatial proximity via an EGFR–CREB5 axis to restore quiescent synovial lining in remission rheumatoid arthritis
doi: 10.64898/2025.12.10.693501
Figure Lengend Snippet: Bulk RNA-seq of CREB5 KD in patient-derived synovial fibroblasts reveals CREB5-dependent integration of cell density in fibroblast lineage programs. A. Representative immunoblots of pCREB5 (T61) and total CREB5 in synovial fibroblasts after CREB5 knockdown, cultured at low (20 cells/mm²) or high (100 cells/mm²) density, with GAPDH as loading control (top). Densitometric quantification of pCREB5 (T61) and total CREB5 normalized to GAPDH (bottom). B. PCA of the normalized gene expression values after batch correction for individual cell line variability. Each point represents the expression profile of one sample. C. GO terms enrichment analysis showing the functional pathways associated with genes upregulated or downregulated in response to CREB5 KD across different cell densities. D. Expression profiles of synovial lining markers ( PRG4 , PDPN , CLU ) and sublining markers ( POSTN , THBS1 , COL1A1 ) across four cell densities in control and CREB5 KD conditions. E. Fisher’s exact test showing the enrichment of AMP-defined lining genes among diffrerntially expressed genes after CREB5 KD. F. Immunoblot analysis of pCREB (S133) and total CREB5 in synovial fibroblasts cultured at 100 cells/mm² for 3 days and stimulated with forskolin (10 μM, 30 min) or DMSO (0.1%, control) prior to lysis, with β-actin as loading control. G. qRT-PCR analysis of lining markers in Synovial fibroblast cultured at at low (20 cells/mm²) and high (100 cells/mm²) density for 6 hours followed by stimulation with forskolin (7 μM) or 0.1% DMSO control for 72 hours. Data represent biological triplicates, and P values are indicated above the bars.
Article Snippet: Membranes were blocked for 15 minutes in Everyblot blocking buffer (Bio-Rad # 12010020) then incubated overnight at 4°C with primary antibodies against CREB5 (Proteintech, #14196-1-AP, 1:500 dilution), p-CREB (Cell Signaling Technology, #9198, 1:500), EGFR (Proteintech, # 66455-1-Ig),p-EGFR (Cell Signaling Technology, #3777), p-ATF2(Cell Signaling Technology, # 24329, 1:300), SOX5 (Proteintech, #13216-1-AP, 1:500), FOXO1 (Proteintech, #18592-1-AP, 1:500), EGFR (Proteintech, #66455-1-Ig), GAPDH (Thermo Fisher Scientific, #MA5-15738), ɑ-tubulin (11224-1-AP), or beta-actin (Cell Signaling Technology, #3700).
Techniques: RNA Sequencing, Derivative Assay, Western Blot, Knockdown, Cell Culture, Control, Gene Expression, Expressing, Functional Assay, Lysis, Quantitative RT-PCR