Fig. 2: IL-37d inhibited pro-inflammatory cytokines expression.

a–c A549 cells were transfected with the mock, IL-37b, or IL-37d recombinant plasmid, respectively, and stimulated with or without IL-1β (10 ng/ml) for the indicated times. The expressions of IL-37b and IL-37d were detected by RT-PCR (a) and western blot (b). The levels of IL-6 in the cell culture supernatants were determined by ELISA (c). The expression of IL-37d in bone marrow-derived macrophages (BMDMs) from wild-type and IL-37dtg mouse was detected by RT-PCR (d). BMDMs were stimulated with or without LPS (100 ng/ml) for 3 h, 6 h, or 9 h. The mRNA levels of IL-1α, IL-1β, IL-6, and TNF-α were determined by qRT-PCR (e–h) and the levels of IL-6 and TNF in the cell culture supernatants were determined by cytometric beads array (CBA) (i, j). ND, Not detectable. *P < 0.05; **P < 0.01; ***P < 0.001, ns, no significant difference. Data are shown as the mean ± SEM from three independent experiments