Fig. 4

ASA treatment rescues the impaired immunomodulation capacity of iGMSCs via upregulation of FasL. a Western blot analysis showed that FasL siRNA downregulated the expression level of FasL in ASA-iGMSCs. b, c In vitro co-culture system showed that FasL siRNA-treated ASA-iGMSCs was not able to sufficiently induce Annexin V⁺/7AAD⁺ T cell apoptosis compared with untreated ASA-iGMSCs. d–f FasL siRNA-treated ASA-iGMSCs showed decreased immunomodulation capacity compared with untreated ASA-iGMSCs, as assessed by d amelioration of losing body weight, e decreased disease activity index (DAI), and f alleviation of colitis histologic activity index (HAI). g FasL siRNA treatment inhibits ASA-iGMSCs’ ability to reduce the levels of Th1 and Th17 cells and elevate the levels of Treg cells in colitis mice. h FasL siRNA treatment inhibits ASA-iGMSCs’ ability to downregulate the serum levels of TNF-α and IL-17 in colitis mice. n = 5 in each group. Scale bar = 200 μm. *P < 0.05. **P < 0.01. ***P < 0.005. Error bars: mean ± SD