Fig. 6

KYN or KYNA activates AHR signaling pathway to enhance TSG-6 production. a hMuSCs treated with IFN-γ (10 ng/ml) and TNF-α (10 ng/ml) were examined for the receptor of KYN and KYNA expression by real-time PCR. b, c hMuSCs were treated with IFN-γ (1 ng/ml) and TNF-α (10 ng/ml) in the presence of DMSO, KYN (400 μM), or KYNA (200 μM) for 24 h. The expression of CYP1A1 and CYP1B1 were examined by real-time PCR. d, e The expression of CYP1A1 and CYP1B1 in hMuSCs treated as in b in the presence or absence of CH-223191 for 24 h were examined by real-time PCR. f, g The expression of TSG-6 mRNA (left) and protein (right) were examined by real-time PCR and ELISA, respectively. Results were shown as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001; ns, no significance