Ishimoto Haruka, Oshima Tadayuki, Sei Hiroo, Yamasaki Takahisa, Kondo Takashi, Tozawa Katsuyuki, Tomita Toshihiko, Ohda Yoshio, Fukui Hirokazu, Watari Jiro, Miwa Hiroto
Division of Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.
J Clin Biochem Nutr. 2017 Mar;60(2):146-150. doi: 10.3164/jcbn.16-92. Epub 2017 Feb 16.
Intestinal epithelial barrier function is impaired in irritable bowel syndrome patients. Claudins are highly expressed in cells with tight junctions and are involved in the intestinal epithelial barrier function. The expression pattern of tight junction proteins in diarrhea-predominant irritable bowel syndrome have not been fully elucidated. We therefore recruited 17 diarrhea-predominant irritable bowel syndrome patients and 20 healthy controls. The expression of the tight junction-related proteins was examined in the ileal, cecal, and rectal mucosa of diarrhea-predominant irritable bowel syndrome patients using real-time PCR and immunofluorescence. Claudin-2 expression was high in the ileum of diarrhea-predominant irritable bowel syndrome patients. Claudin-2 expression was the same in cecum and rectal mucosa of control and diarrhea-predominant irritable bowel syndrome patients. Similarly, the expression of clauidn-1, claudin-7, JAM-A, occludin, and ZO-1 in the ileal, cecal, and rectal mucosa did not change between control and diarrhea-predominant irritable bowel syndrome samples. Infiltration of eosinophil and mast cells in the mucosa of ileum, cecum and rectum was evaluated using immunohistochemical staining and was not affected by diarrhea-predominant irritable bowel syndrome. Claudin-2 was expressed on the apical side of villi and crypts of ileal mucosal epithelial cells. Clauidn-2 expression is upregulated in diarrhea-predominant irritable bowel syndrome patients and may contribute to the pathogenesis of this condition.
肠易激综合征患者的肠道上皮屏障功能受损。紧密连接蛋白在具有紧密连接的细胞中高度表达，并参与肠道上皮屏障功能。腹泻型肠易激综合征中紧密连接蛋白的表达模式尚未完全阐明。因此，我们招募了17名腹泻型肠易激综合征患者和20名健康对照者。使用实时PCR和免疫荧光法检测腹泻型肠易激综合征患者回肠、盲肠和直肠黏膜中紧密连接相关蛋白的表达。腹泻型肠易激综合征患者回肠中Claudin-2表达较高。对照者和腹泻型肠易激综合征患者的盲肠和直肠黏膜中Claudin-2表达相同。同样，对照样本和腹泻型肠易激综合征样本的回肠、盲肠和直肠黏膜中Claudin-1、Claudin-7、JAM-A、闭合蛋白和ZO-1的表达没有变化。使用免疫组织化学染色评估回肠、盲肠和直肠黏膜中嗜酸性粒细胞和肥大细胞的浸润情况，其不受腹泻型肠易激综合征的影响。Claudin-2在回肠黏膜上皮细胞绒毛和隐窝的顶端表达。腹泻型肠易激综合征患者中Claudin-2表达上调，可能与该疾病的发病机制有关。
