Effect of food-derived intestinal content such as fatty acids on intestinal mucosal barrier

1.一氧化氮(NO)对肠上皮通透性的影响及紧密连接蛋白(Occludin)NO供体对Caco-2细胞单层通透性的影响一氧化氮合酶抑制剂可抑制牛磺胆酸诱导的高通透性。在NO供体存在的情况下，将FITC-葡聚糖加入到根尖室后1小时，在细胞旁间隙观察到荧光。在NO供体存在的情况下，封闭素的高分子量条带变得模糊。在NO供体存在的情况下，用抗磷丝氨酸抗体获得的与occuludin的高分子量条带相对应的条带变得模糊。在无供体存在的情况下，封闭素在紧密连接处染色，但染色范围略宽于对照组。这些结果表明，肠上皮细胞通透性的增加不仅与外源性NO有关，也与肠上皮细胞产生的NO有关。通透性的增加似乎是由于扩张性…更多关于紧密连接，这与occuludin的去磷酸化有关。脂肪酸对肠上皮细胞趋化因子产生的影响短链脂肪酸丁酸降低肠上皮细胞IL-8的产生，ω-3脂肪酸如二十二碳六烯酸和二十碳五烯酸对IL-8的产生无影响。油酸(OA)和没食子酸(CA)促进IL-8的产生。蛋白激酶C和磷脂酶A2参与了OA诱导的IL-8产生的信号转导途径，但不参与CA诱导的IL-8产生的信号转导途径。全肠灌洗液(WGLF)和粪便中蛋白质的测定可作为研究炎症性肠病(IBD)患者的病理生理和疾病活动性的样本。活动期IBD患者上清液和颗粒中颗粒蛋白浓度均升高，颗粒蛋白上清液/颗粒比值降低。这些发现表明，尽管活动期IBD中性粒细胞向管腔内的迁移显著增加，但迁移到管腔内的许多中性粒细胞并不释放颗粒蛋白。较少

1. Effect of nitric oxide (NO) on intestinal epithelial permeability and tight junction protein (occludin)NO donors increased the permeability of the Caco-2 cell monolayer. NOS inhibitors suppressed taurocholate-induced hyperpermeability. In the presence of NO donor, fluorescence was observed at the paracellular space one hour after the addition of FITC-dextran to the apical compartment. In the presence of NO donor, the higher molecular-weight band of occludin became faint. In the presence of NO donor, bands obtained using anti-phophoserine antibody corresponding with the higher molecular-weight band of occuludin became faint. In the presence of NO donor, occludin was stained at the tight junction but the stain was a little broader than that in the control. These findings suggested that intestinal epithelial permeability is increased not only by exogenously administered NO but also by NO produced by intestinal epithelial cells. The increased permeability appears to be due to the dilati … More on of the tight junction, which is associated with the dephosphorylation of occuludin.2. Effect of fatty acids on chemokine production in intestinal epithelial cells, Caco-2 cellsButyate, short-chain fatty acid, decreased interleukin(IL)-8 production in intestinal epithelial cells.ω-3 fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) showed no effect on IL-8 production. Oleic acid (OA) and capric acid (CA) increased IL-8 production. Proteainkinase C and phospholipase A2 were involved in signal transduction pathways for OA-induced IL-8 production but not for CA-induced IL-8 production.3. Measurement of proteins in whole gut lavage fluid (WGLF) and fecesEither WGLF or feces can be used as a sample to investigate pathophysiology and disease activity in patients with inflammatory bowel disease (IBD). In active IBD, the concentrations of granular proteins were increased both in the supernatant and pellet, and the supernatant/pellet ratios of granular proteins were decreased. These findings suggested that although the migration of neutrophils into the lumen is extremely increased in active IBD, a number of neutrophils that migrated into the lumen did not release granular proteins. Less