Cellular expression of monocarboxylate transporters (MCT) in the digestive tract of the mouse, rat, and humans, with special reference to slc5a8
Cellular expression of monocarboxylate transporters (MCT) in the digestive tract of the mouse, rat, and humans, with special reference to slc5a8
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DOI：
10.2220/biomedres.27.243
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发表时间：
2006-10-01
影响因子：
1.2
通讯作者：
Kuwahara, Atsukazu
中科院分区：
文献类型：
--
作者：
Iwanaga, Toshihiko;Takebe, Kumiko;Kuwahara, Atsukazu
短链脂肪酸（SCFA）是由细菌发酵产生的单羧酸盐，在维持大肠内稳态中起着至关重要的作用。SCFA的两种主要转运蛋白，单羧酸转运蛋白（MCT）和slc5a8（或SMCT），存在于消化道中。本组织化学研究采用原位杂交和免疫组织化学揭示了MCT家族在小鼠、大鼠和人类消化道中的分布和亚细胞定位，并将其与slc5a8进行了比较。MCT1在小鼠和大鼠的粘膜中的表达在盲肠中最强，其次是结肠，而在胃和小肠中的表达较低。在其他MCT亚型中，仅在胃粘膜的壁细胞区域中检测到MCT 2。Slc5a8在大肠的远侧半部分和最末端回肠中具有主要表达位点。粘膜MCT 1定位于肠上皮细胞的基底外侧膜，而slc5a8仅限于顶端细胞膜，表明slc5a8参与腔SCFA的摄取，MCT 1参与SCFA和单羧酸代谢物向血液循环的流出。大肠表达这两种类型的转运蛋白，但它们的分布模式不同，沿着纵轴的肠和沿着垂直轴的粘膜。
Short-chain fatty acids (SCFA) are monocarboxylates produced by bacterial fermentation that play a crucial role in maintaining homeostasis in the large intestine. Two major transporters for SCFA, monocarboxylate transporter (MCT) and slc5a8 (or SMCT), exist in the digestive tract. The present histochemical study using in situ hybridization and immunohistochemistry revealed the distribution and subcellular localization of the MCT family in the digestive tract of mice, rats, and humans, comparing these with that of slc5a8. The expression of mucosal MCT1 in the mouse and rat was most intense in the cecum, followed by the colon, but low in the stomach and small intestine. Among other MCT subtypes, only MCT2 was detected in the parietal cell region of the gastric mucosa. Slc5a8 had predominant expression sites in the distal half of the large bowel and in the most terminal ileum. The mucosal MCT1was localized in the basolateral membrane of enterocytes, while slc5a8 was restricted to the apical cell membrane, suggesting the involvement of slc5a8 in the uptake of luminal SCFA, and of MCT1in the efflux of SCFA and monocarboxylate metabolites towards blood circulation. The large intestine expressed both types of the transporter, but their distribution patterns differed along the longitudinal axis of the intestine and along the perpendicular axis of the mucosa.