Fig. 6

Contribution of the Mertk inhibitor to the IL-37-mediated anti-inflammatory effect in monosodium urate (MSU)-induced models in vitro and in vivo. a–c Concentration of secreted IL-1β, IL-8 and CCL2 in THP-1 macrophages treated with or without recombinant human IL-37 (rhIL-37) for 3 h, followed by incubation for 1 h with or without Mertk inhibitor and then incubated with lipopolysaccharide (LPS) or MSU separately for a further 18 h; *P < 0.05. d Different dosage of rhIL-37 was given preventively or therapeutically with or without Mertk inhibitor intervention in mice with gouty arthritis, and foot thickness was evaluated; *P < 0.05. e, f Histopathological analysis by H&E staining in a joint from the group treated with rhIL-37 treatment and Mertk inhibitor intervention (×100 original magnification (e) and × 200 original magnification (f); arrow inflammation in soft tissue and joint space. g–k The protein level of Smad3, IL-1R8, S​OCS3 and NLRP3 was verified by western blotting in the IL-37 treatment groups with or without Mertk inhibitor intervention. Protein levels in different groups were expressed as a ratio to that of corresponding glyceraldehyde-3-phosphate dehydrogenase (GAPDH); *P < 0.05 **P < 0.01