Fig. 1

Effects of PFD on proliferation of SpA FLSs. a-b Representative light microscopy images of SpA FLSs untreated (UT) and stimulated (TGFβ+TNFα+IFNγ) with or without pirfenidone (PFD). c Representative flow cytometry plots of stimulated FLS treated with pirfenidone (PFD) showing the gating strategy. d-e Representative flow cytometry histograms of Ki67 expression in SpA FLSs untreated (UT) and stimulated (TGFβ+TNFα+IFNγ) with or without PFD. Isotype antibody was used as a negative control of the Ki67 staining. f Column bar graph of percentage of Ki67 positive FLSs among all SpA FLSs untreated (UT) and stimulated (TGFβ+TNFα+IFNγ) with or without PFD (n = 3). Data were normalized to untreated cultures (ratio), log-transformed and analyzed with the paired t-test. Boxes and bars indicate median and IQR. * p < 0.05. ** p < 0.01