壳寡糖对脂多糖诱导肠上皮细胞炎症的保护作用  

Protective effect of oligochitosan on LPS-induced inflammation of the intestinal epithelial cells

作　　者：杨院平[1] 罗和生[1] 仝巧云[2] 李中艳[2] 郑世华[2] 

机构地区：[1]武汉大学人民医院消化内科,武汉430060 [2]三峡大学消化病研究所、宜昌市中心人民医院

出　　处：《中华生物医学工程杂志》2015年第4期325-329,共5页Chinese Journal of Biomedical Engineering

摘　　要：目的：研究壳寡糖对脂多糖（LPS）诱导肠上皮细胞炎症的影响。方法肠上皮细胞Caco-2分为5组：正常对照组、模型组、壳寡糖高、中、低浓度组。以1μg/L LPS刺激细胞48h建立炎症模型。药物干预组于LPS刺激前2 h，分别以0.25，0.5和1.0 g/L壳寡糖预处理细胞。MTT法检测细胞活力。以ELISA法检测培养上清中炎症相关因子肿瘤坏死因子（TNF）-α，白介素（IL）-8和前列腺素（PG）E2水平。以Western印迹法检测细胞Toll样受体（TLR）4、核因子κB（NF-κB）及环氧酶（COX）2的表达变化。结果壳寡糖和/或LPS处理后Caco-2细胞存活率不受影响。与模型组相比，壳寡糖在0.25，0.5和1.0 g/L剂量下呈浓度依赖性地降低Caco-2细胞TNF-α（352.5±21.6，298.4±25.1，203.4±20.0 vs 436.8±38.7μg/L）和PGE2的释放（632.2±35.6，522.6±26.7，402.4±30.2 vs 822.3±23.5μg/L）（P〈0.05；P〈0.01），0.5和1.0 g/L壳寡糖可降低细胞COX-2表达水平（P〈0.05；P〈0.01）。壳寡糖中、高浓度组TLR4表达明显低于模型组（P〈0.05），壳寡糖各剂量组NF-κB的表达水平显著降低（P〈0.05；P〈0.01）。结论壳寡糖可对抗LPS诱导的肠上皮细胞炎症，对炎性肠病具潜在保护作用。作用机理可能与TLR4／NF-κB信号通路抑制有关。Objective To investigate the protective effect of oligochitosan on lipopolysaccharide （LPS）induced inflammation of the intestinal epithelial cells. Methods intestinal epithelial cells Caco-2 were divided into five groups：normal control group,model group,high-,medium- and low-level oligochitosan groups. In the oligochitosan groups,the cells were pre-treated with 0.25,0.5 and 1.0 g/L oligochitosan,respectively,at 2 h before LPS stimulation. MTT method was used for cell viability assay. ELISA was used to measure the levels of inflammation related cytokines,such as tumor necrotizing factor-related factor alpha （TNF-α）,interleukin-8 （IL-8） and prostaglandin E2 （PGE2）,in the cell culture supernatant. Western blotting was used to detect the changes in expression of Toll-like receptor 4（TLR4）, nuclear factor κB（NF-κB）and cyclooxygenase 2（COX-2）. Results The Caco-2 cell viability was not affected by treatment with oligochitosan and/or LPS. Compared with the model group,0.25,0.5 and 1.0 g/L oligochitosan reduced the production of TNF-α（352.5±21.6,298.4±25.1,203.4 ±20.0 vs 436.8±38.7μg/L, P〈0.05）and PGE2（632.2±35.6,522.6±26.7,402.4±30.2 vs 822.3±23.5μg/L,P〈0.01）in Caco-2 cells in a dose dependent manner;0.5 and 1.0 g/L oligochitosan reduced COX 2 expression（P〈0.05 and P〈0.01）;medium-and high-level oligochitosan was significantly associated with lowered expression of TLR 4 compared with the model group （P〈0.05）;the expression of NF-κB in each group of oligochitosan dosage was significantly lowered （P〈0.05;P〈0.01）. Conclusion Oligochitosan may reverse LPS - induced inflammation of the intestinal epithelial cells and therefore may be potentially protective against inflammatory bowel diseases. The underlysing mechanism of this action may be related to inhibition of TLR4/NF-κB signaling pathway.

关 键 词：炎症 肠上皮细胞 脂多糖 壳寡糖 TLR4 

分 类 号：R574[医药卫生—消化系统]