Cytokine-stimulated human amniotic epithelial cells alleviate DSS-induced colitis in mice through anti-inflammation and regulating Th17/Treg balance.

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon characterized by immune dysregulation. Restoration of the balance between regulatory T (Tregs) and T helper 17 (Th17) cells improves UC symptoms. Human amniotic epithelial cells (hAECs) have emerged as a promising therapeutic option for UC because of their immunomodulatory properties. In this study, we aimed to optimize and maximize the therapeutic potential of hAECs by pre-treating them with tumor necrosis factor (TNF)-α and interferon (IFN)-γ (pre-hAECs) for UC treatment. We evaluated the efficacy of hAECs and pre-hAECs in treating dextran sulfate sodium (DSS)-induced colitis mice. Compared to hAECs, pre-hAECs were found to be more effective in alleviating colitis in acute DSS mouse models than in the controls. Additionally, pre-hAEC treatment significantly reduced weight loss, shortened the colon length, decreased the disease activity index, and effectively maintained the recovery of colon epithelial cells. Furthermore, pre-hAEC treatment significantly inhibited the production of pro-inflammatory cytokines, such as interleukin (IL)-1β and TNF-α, and promoted the expression of anti-inflammatory cytokines, such as IL-10. Both in vivo and in vitro studies revealed that pre-treatment with hAECs significantly increased the number of Treg cells, decreased the numbers of Th1, Th2, and Th17 cells, and regulated the balance of Th17/Treg cells. In conclusion, our results revealed that hAECs pre-treated with TNF-α and IFN-γ were highly effective in treating UC, suggesting their potential as therapeutic candidates for UC immunotherapy.