P0193 Oral administration of Sophora Flavescens-derived exosomes-like nanovesicles carrying CX5461 ameliorates DSS-induced colitis in mice

Abstract Background Ulcerative colitis (UC) belongs inflammatory disease with chronic and relapsing characterizations and increased-cancer risk. CX5461 has been demonstrated the important roles in autoimmune disease, immunological rejection, and macrophage-mediated vascular inflammation. However, whether CX5461 can serve as UC therapeutic drug remains unclear. The objective of this study is to investigate the therapeutic effect of oral administration of SFELNVs@CX5461 on DSS-induced colitis and its possible molecular mechanism. Methods SFELNVs were extracted and the morphology were charactered. The preparation of SFELNVs@CX5461 were electroporated and the loading efficiency of SFELNVs@CX5461 were calculated. We conducted the experiments using SFELNV, CX5461 and SFELNVs@CX5461 respectively. Proliferation and apoptosis of RAW264.7 cells were detected by flow cytometry according to the kits. C57BL/6 mice (8 weeks, 18-20g) were induced by 3% DSS in drinking water for a week to establish the colitis model. Then, DSS-induced C57BL/6 colitis mice models were orally administrated with SFELNVs@CX5461 (n=5, 80mg/kg) and SFELNVs (n=5, 80mg/kg) for 5 days. The body weight, consistency of stool, and rectal bleeding were measured each day. Finally, after sacrificing the mice, colons and main organs were obtained for the qPCR, HE, and IHC. Results Cellular uptake has shown that SFELNVs were targeted uptake by macrophages, thus increasing drug concentration. Additionally, Oral SFELNVs@CX5461 exhibited good safety and stability, as well as inflammation-targeting ability in the gastrointestinal tract of dextran sodium sulfate (DSS)-induced colitis mice. In vivo, Oral administration of SFELNVs and CX5461 could relieve mice colitis. More importantly, combined SFELNVs and CX5461 enhanced the treatment efficacy of mice colitis by inhibiting pro-inflammatory factors (TNF-α, IL-1β, and IL-6) expression and promoting M2 macrophage infiltration. Furthermore, SFELNVs promoted M2 polarization by miR4371c using miRNA sequencing. Our results suggest that SFELNVs@CX5461 represents a novel orally therapeutic drug that can ameliorate colitis, and a promising targeting strategy for safe and effective UC therapy. Conclusion In summary, SFELNVs@CX5461 represents a therapeutic strategy to UC with excellent biocompatibility due to the ability to enhance anti-inflammatory effects in vitro and in vivo to alleviate UC. References [1]T. Kobayashi, B. Siegmund, C. Le Berre, S.C. Wei, M. Ferrante, B. Shen, C.N. Bernstein, S. Danese, L. Peyrin-Biroulet, T. Hibi, Ulcerative colitis, Nat Rev Dis Primers, 6 (2020) 74. [2]X. Yan, L. Meng, X. Zhang, Z. Deng, B. Gao, Y. Zhang, M. Yang, Y. Ma, Y. Zhang, K. Tu, M. Zhang, Q. Xu, Reactive Oxygen Species-Responsive Nanocarrier Ameliorates Murine Colitis by Intervening Colonic Innate and Adaptive Immune Responses, Mol Ther, (2023). [3]Y.N. Wang, J. Li, W.Y. Zheng, D. Wu, H. Yang, Y. Li, H. Lv, B. Tan, H.J. Shu, X.Y. Sun, J.M. Qian, B. Wu, J.N. Li, Clinical characteristics of ulcerative colitis-related colorectal cancer in Chinese patients, J Dig Dis, 18 (2017) 684-690. [4]R. Ungaro, S. Mehandru, P.B. Allen, L. Peyrin-Biroulet, J.F. Colombel, Ulcerative colitis, Lancet, 389 (2017) 1756-1770.