中文摘要：

维生素A（vitamin A,VA）在维持肠道黏膜上皮屏障功能的完整性、调节黏膜免疫反应以及抗感染中起到重要的作用。肠道相关树突状细胞（dendritic cells,DCs）可表达合成视黄酸（retinoic acid,RA）所必需的酶（retinal dehydrogenase,RALDH）,合成RA。RA通过诱导T、B细胞产生整合素α4β7、CCR9,使其归巢到肠道,并提高肠道黏膜sIgA的水平。RA可增强天然CD4＋T细胞分化为Foxp3＋Treg细胞,抑制Th17细胞的生成。当机体VA缺乏时可降低肠道屏障功能,下调肠道黏膜免疫反应,增加肠道感染性疾病的易感性,容易导致腹泻。针对维生素A在肠道屏障功能的调节作用作一简要概述。

英文摘要：

Vitamin A plays important roles on maintaining epithelial barrier integrity,regulating mucosal immune function against several infections.Retinoic acid synthesizing enzymes（RALDH） is expressed in the gut-associated dendritic cells to produce RA.RA can up-regulate expression levels of integrin α4β7、CCR9 of T and B lymphocytes,which enhance the T and B lymphocytes preferentially homing to the small intestine and induce secretion of immunoglobulin-A（IgA）.RA also promotes the differentiation of native CD4＋T cells into Foxp3＋ inducible regulatory T cells（Treg）,and represses the proliferation of Th17 cells.Increasing evidences have demonstrated that vitamin A deficiency may decrease intestinal epithelial barrier function and down-regulate intestinal local mucosal immune responses,resulting in increased susceptibility of intestinal infection and risk of diarrhea.The current paper reviewed the regulatory effects of vitamin A on the intestinal barrier function.