Extended Data Fig. 3: Endothelial cells mediate the differentiation of THY1-expressing fibroblasts.
From: Notch signalling drives synovial fibroblast identity and arthritis pathology
a, Fibroblast positional identity scores of CD90+ (red) and CD90− (blue) fibroblasts at the indicated passage number (fresh, n = 7 and n = 15; passage 1, n = 7 and n = 16; passage 2, n = 4 and n = 8). Box plots summarize the median, interquartile range and 95% quantiles of the positional values. b, Positional identity of fibroblasts from the fibroblast-only (top, n = 4,336 cells) and fibroblast + endothelial cell (bottom, n = 2,076 cells) organoids. Cells are coloured by their inferred position along positional axis from 0 (perivascular pole) to 100 (lining pole). Perivascular fibroblasts (red) were defined as cells with a position of less than 20, and intermediate fibroblasts were defined as being located at positions between 20 and 80. c, Flow cytometric quantification of synovial CD90+ fibroblasts and CD31+ endothelial cells from 22 synovial tissues. d, Percentage of CD90+ fibroblasts based on Doppler ultrasound scores of patients with rheumatoid arthritis (n = 20) from the AMP-RA/SLE consortium. e, THY1 expression measured by PCR with reverse transcription in fibroblasts after stimulation with the indicated recombinant proteins (n = 3 replicates for WNT3A and WNT5A, n = 4 replicates for other conditions). THY1 expression is shown as fold-change compared with the vehicle control for each condition. Significance is determined by a one-sample t-test. f–h, scRNA-seq analysis of synovial organoids (n = 22,164 cells from 3 technical replicates). f, Normalized expression of defining marker gene for cell types: MKI67 for proliferating fibroblasts, VWF for endothelial cells, and THY1 for the THY1high and THY1low fibroblast groups. g, Representation of four major cell types by proportion of cells in each organoid condition. h, Notch activation score in fibroblasts derived from organoids, separated by organoid condition. Significance is determined by Spearman correlation (c, d) and one-sample Student’s t-test (e).
