Fig. 6

FSTL1 guarantees immunosuppressive function of MSCs on macrophages by regulating JAK/STAT1/IDO pathway. MSCs were transfected with siFSTL1. RNA expression of FSTL1 and IDO was determined by qRT-PCR at 12 h post transfection (A). Protein level of FSTL1, IDO, and pSTAT1 was determined by western blotting at 24 h post transfection (B). C–D: MSC transfected with siFSTL1treated with or without FSTL1 (100 ng/ml). IDO mRNA was determined by qRT-PCR at 12 h post FSTL1 treatment (C). Protein level of FSTL1, IDO, and pSTAT1 was determined by western blotting at 24 h post FSTL1 treatment (D). E–F: MSC transfected with siFSTL1treated with or without 2-NP (15 ug/ml). IDO mRNA was determined by qRT-PCR at 12 h post 2-NP treatment (E). Protein level of FSTL1, IDO, and pSTAT1 was determined by western blotting at 24 h post 2-NP treatment (F). G-I: MSC transfected with siFSTL1treated with or without 2-NP treatment were co-cultured with Raw264.7 cells. The proportions of CD206-positive macrophages were determined after 24 h co-culture with MSCs (G). The mean percentages of CD206-positive cells in total macrophages were summarised (H). Expression of differential markers in macrophages evaluated by qPCR under different conditions after 12 h co-culture with MSCs (I). ***, P < 0.001; **, P < 0.01; *, P < 0.05. All experiments were performed in triplicate. Error bars indicate the mean ± SEM