Wen Zhong-Hui, Quyang Qin, Zhang Hu, Yi Zhi-Hui, Wang Yu-Fang
Department of Gastroenterology, West China Hospital of Sichuan University, Chengdu 610041, China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2005 Sep;36(5):676-8.
Interleukin-18 (IL-18) is a proinflammatory cytokine that induces Th1 cytokines production and may play a role in the pathogenesis of inflammatory bowel diseases. This study was aimed at detecting the expression and role of IL-18 in colonic mucosa of dextran sulfate sodium (DSS) colitic mice.
Expression of IL-18 in colon of DSS colitis was determined by immunohistochemistry. Extract and supernatant of intestinal epithelial cells (IEC) from colon of DSS colitis mice were used to stimulate splenic mononuclear cells (SMC); IFN-gamma and IL-2 concentrations in supernatant of SMC were measured by ELISA. The levels of expression of IL-18 in extract or supernatant of IEC were examined by Western blot.
Colon epithelial cells and part of lamina propria mononuclear cells were stained positive for IL-18 antibody. Stimulation assay and Western blot indicated that IL-18 positive proteins were present in both IEC extract and supernatant.
Colon epithelial cells in mice with DSS colitis express and secret pro IL-18 and active IL-18.
白细胞介素-18（IL-18）是一种促炎细胞因子，可诱导Th1细胞因子的产生，并可能在炎症性肠病的发病机制中起作用。本研究旨在检测IL-18在葡聚糖硫酸钠（DSS）结肠炎小鼠结肠黏膜中的表达及作用。
采用免疫组织化学法检测DSS结肠炎小鼠结肠中IL-18的表达。用DSS结肠炎小鼠结肠的肠上皮细胞（IEC）提取物和上清液刺激脾单核细胞（SMC）；采用酶联免疫吸附测定法（ELISA）检测SMC上清液中γ干扰素（IFN-γ）和白细胞介素-2（IL-2）的浓度。通过蛋白质印迹法检测IEC提取物或上清液中IL-18的表达水平。
结肠上皮细胞和部分固有层单核细胞的IL-18抗体染色呈阳性。刺激试验和蛋白质印迹法表明，IEC提取物和上清液中均存在IL-18阳性蛋白。
DSS结肠炎小鼠的结肠上皮细胞表达并分泌前体IL-18和活性IL-18。
