Fig. 1: Expression of NR1D1 in synovial tissue and FLSs of patients with RA.

a NR1D1 expression in synovial tissues. Representative images of immunohistochemical staining of tissues from patients with RA (n = 8) and OA (n = 4). Quantitative analyses (below) and representative images (upper, original magnification 10×, scale bar = 100 μm). b RA FLSs were incubated with IL-1β, TNF-α, IL-17, and LPS for 24 h (left). The NR1D1 mRNA level was determined by qRT-PCR. Data are means ± SEM of three independent experiments. *p < 0.05, **p < 0.01 versus the control group. c Representative western blots of NR1D1, IL-1β, COX-2, MMP3, and MMP13 in RA FLSs stimulated with IL-1β or TNF-α at the indicated concentrations for 72 h. d Representative western blots of NR1D1, IL-1β, COX-2, MMP3, and MMP13 in RA FLSs stimulated with IL-1β or TNF-α for the indicated times. e, f Flow cytometric analysis of apoptosis. RA FLSs were exposed to SR9009 (1–10 μM) for 24 h, stained using an Annexin V/PI apoptosis kit, and subjected to flow cytometry. Data are means ± SEM of three independent experiments; *p < 0.05 versus the control group.