M1671 All-Trans Retinoic Acid Downregulates Inflammatory Responses By Shifting the Treg/TH17 Profile in Human Ulcerative and Murine Colitis

5*106 each mouse subsequently.Saline was used as a control.Colon sections were prepared for H&E staining to determine intestinal inflammation by DAI score.CM-DiI-labeled hUCMSCs were detected by CONFOCAL and Optical In Vivo Imaging system (XENOGEN IVIS200).The effects of hUCMSCs on T cells proliferation were studied In Vitro by BrdUlabeled method and concentrations of IL-17, IL-23 and IFN-g were measured by ELISA.Results: The SCID mice developed intestinal inflammation 3-5 weeks after first transplantation, which was similar to that in human IBD patients.The lesions of treated mice were improved in mice with CM-DiI hUCMSCs treatment after second transplantation, which DAI score decreased from 3.1 to 1.3.CM-DiI+ hUCMSCs, which were detected by In Vivo Imaging system, were also recovered in intestinal mucosa and submucosa of the colon by CONFOCAL.Furthermore, hUCMSCs inhibited mice T cell response to antigen stimulation In Vitro in a dose-dependent manner and production of proinflammatory cytokines was lower, indicating the immunosuppressive activity of hUCMSCs.CONCLUSION: Systemically administrated hUCMSCs responded to an adequate tissue lesion and resulted in accelerated tissue repair in mouse IBD.hUCMSC transplantation may serve as a potential approach for IBD treatment.