Curcumin alleviates experimental colitis <i>via </i>a potential mechanism involving memory B cells and Bcl-6-Syk-BLNK signaling
Siyi Wei, Tiantian Wu, Jiaqi Huang, Zeng-Ping Kang, Mengxue Wang, Youbao Zhong, Wei Ge, Bu-Gao Zhou, Haimei Zhao, Haiyan Wang, Duan‐Yong Liu
Abstract
BACKGROUND: Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease (IBD), which is mainly related to lymphocytes (T or B cells, incl-uding memory B cells), mast cells, activated neutrophils, and macrophages. As the precursor of B cells, the activation of memory B cells can trigger and differentiate B cells to produce a giant variety of inducible B cells and tolerant B cells, whose dysfunction can easily lead to autoimmune diseases, including IBD. AIM: To investigate whether or not curcumin (Cur) can alleviate experimental colitis by regulating memory B cells and Bcl-6-Syk-BLNK signaling. METHODS: Colitis was induced in mice with a dextran sulphate sodium (DSS) solution in drinking water. Colitis mice were given Cur (100 mg/kg/d) orally for 14 con-secutive days. The colonic weight, colonic length, intestinal weight index, occult blood scores, and histological scores of mice were examined to evaluate the curative effect. The levels of memory B cells in peripheral blood of mice were measured by flow cytometry, and IL-1β, IL-6, IL-10, IL-7A, and TNF-α expression in colonic tissue homogenates were analyzed by enzyme-linked immunosorbent assay. Western blot was used to measure the expression of Bcl-6, BLNK, Syk, and other signaling pathway related proteins. RESULTS: B cells increased significantly. In addition, Cur significantly inhibited the protein levels of Syk, p-Syk, Bcl-6, and CIN85, and increased BLNK and p-BLNK expression in colitis mice. CONCLUSION: Cur could effectively alleviate DSS-induced colitis in mice by regulating memory B cells and the Bcl-6-Syk-BLNK signaling pathway.