Fig. 5.
Exogenous KYN or KYNA rescues the loss of therapeutic effects of IDO-KD-hMuSCs on IBD through augmenting TSG-6 expression. a Ctrl-hMuSCs were treated with IFN-γ (10 ng/ml) and TNF-α (10 ng/ml), and IDO-KD-hMuSCs were treated with IFN-γ (10 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 TSG-6 mRNA (left) and protein (right) were examined by real-time PCR and ELISA. b These cells (2.5 × 105 cells per mouse) treated as in a for 48 h were intravenously injected into IBD mice on day 2. Changes in body weight during the entire experiment showed as the percentage of the initial body weight on day 0. c Colon length of IBD mice was assessed. d H&E staining of the colon sections and histological scores were shown. e IL-6 in the serum of IBD mice was analyzed by ELISA. Five mice per group were used. Scale bars, 100 μm. Results were shown as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001