Kaempferol Enhances Intestinal Barrier Function through the Cytoskeletal Association and Expression of Tight Junction Proteins in Caco-2 Cells
Kaempferol Enhances Intestinal Barrier Function through the Cytoskeletal Association and Expression of Tight Junction Proteins in Caco-2 Cells
复制标题
DOI：
10.3945/jn.110.125633
复制
发表时间：
2011-01-01
影响因子：
4.2
通讯作者：
Hara, Hiroshi
中科院分区：
文献类型：
--
作者：
Suzuki, Takuya;Tanabe, Soichi;Hara, Hiroshi
山奈酚是一种存在于水果、蔬菜和茶中的天然黄酮类化合物，对人体健康具有有益作用。我们研究了山奈酚对人肠Caco-2细胞单层紧密连接（TJ）屏障完整性的促进作用。跨上皮电阻（TER; TJ完整性标志物）在山萘酚给药后的第一个6小时内迅速显着增加，并保持升高，直到48小时，没有任何变化的荧光黄或葡聚糖流量。免疫印迹分析表明，山奈酚促进TJ蛋白，封闭小带（ZO）-1，ZO-2，闭合蛋白，claudin-1，claudin-3，和claudin-4的肌动蛋白细胞骨架协会，这与TER的增加。山奈酚介导的ZO-2和claudin-4的表达相对较小或发生晚于山奈酚促进的细胞骨架协会。共聚焦显微镜显示山奈酚-级分。在给药后6 h，在TJ处发生闭合蛋白和闭合蛋白-3的诱导组装。用甲基-β-环糊精提取胆固醇抑制了山奈酚介导的TER增加。蔗糖密度梯度离心表明，山奈酚处理增加了TJ蛋白在富含胆固醇的脂质微区组分中的分布。两者合计，这些结果表明，膜脂质微区参与山奈酚介导的促进TJ蛋白组装和肠TJ完整性。J.营养141：87-94，2011.
Kaempferol, a natural flavonoid present in fruits, vegetables, and teas, provides beneficial effects for human health. We investigated the promotive effect of kaempferol on tight junction (TJ) barrier integrity in human intestinal Caco-2 cell monolayers. Transepithelial electrical resistance (TER; a TJ integrity marker) across the monolayers rapidly and markedly increased during the first 6 h after kaempferol administration and remained elevated until 48 h without any changes in the lucifer yellow or dextran fluxes. Immunoblot analysis demonstrated that kaempferol promoted the actin cytoskeletal association of the TJ proteins, zonula occludens (ZO)-1, ZO-2, occludin, claudin-1, claudin-3, and claudin-4, which was associated with the increase in TER. Kaempferol-mediated ZO-2 and claudin-4 expression was relatively smaller or occurred later than the kaempferol-promoted cytoskeletal association. Confocal microscopy showed that kaempferol-fraction. induced assembly of occludin and claudin-3 occurred at the TJ at 6 h postadministration. Extraction of cholesterol with methyl-beta-cyclodextrin suppressed the kaempferol-mediated increase in TER. Sucrose density gradient centrifugation showed that the kaempferol treatment increased the TJ protein distributions in the cholesterol-rich lipid microdomain fraction. Taken together, these results indicate that the membrane lipid microdomain is involved in the kaempferol-mediated promotion of TJ protein assembly and intestinal TJ integrity. J. Nutr. 141: 87-94, 2011.