Nio-Kobayashi Junko, Takahashi-Iwanaga Hiromi, Iwanaga Toshihiko
Laboratory of Histology and Cytology, Hokkaido University Graduate School of Medicine, Japan.
J Histochem Cytochem. 2009 Jan;57(1):41-50. doi: 10.1369/jhc.2008.952317. Epub 2008 Sep 15.
Galectin, an animal lectin that recognizes beta-galactoside of glycoconjugates, is abundant in the gut. This IHC study showed the subtype-specific localization of galectin in the mouse digestive tract. Mucosal epithelium showed region/cell-specific localization of each galectin subtype. Gastric mucous cells exhibited intense immunoreactions for galectin-2 and galectin-4/6 with a limited localization of galectin-3 at the surface of the gastric mucosa. Electron microscopically, galectin-3 immunoreactivity coated indigenous bacteria on the gastric surface mucous cells. Epithelial cells in the small intestine showed characteristic localizations of galectin-2 and galectin-4/6 in the cytoplasm of goblet cells and the baso-lateral membrane of enterocytes in association with maturation, respectively. Galectin-3 expressed only at the villus tips was concentrated at the myosin-rich terminal web of fully matured enterocytes. Epithelial cells of the large intestine contained intense immunoreactions for galectin-3 and galectin-4/6 but not for galectin-2. The stratified squamous epithelium of the forestomach was immunoreactive for galectin-3 and galectin-7, but the basal layer lacked galectin-3 immunoreactivity. Outside the epithelium, only galectin-1 was localized in the connective tissue, smooth muscles, and neuronal cell bodies. The subtype-specific localization of galectin suggests its important roles in host-pathogen interaction and epithelial homeostasis such as membrane polarization and trafficking in the gut.
半乳糖凝集素是一种识别糖缀合物中β-半乳糖苷的动物凝集素，在肠道中含量丰富。这项免疫组织化学研究显示了半乳糖凝集素在小鼠消化道中的亚型特异性定位。黏膜上皮显示出每种半乳糖凝集素亚型的区域/细胞特异性定位。胃黏液细胞对半乳糖凝集素-2和半乳糖凝集素-4/6表现出强烈的免疫反应，而半乳糖凝集素-3仅在胃黏膜表面有有限的定位。电子显微镜下，半乳糖凝集素-3免疫反应性覆盖在胃表面黏液细胞上的原生细菌。小肠上皮细胞分别在杯状细胞的细胞质和肠上皮细胞的基底外侧膜中显示出与成熟相关的半乳糖凝集素-2和半乳糖凝集素-4/6的特征性定位。仅在绒毛尖端表达的半乳糖凝集素-3集中在完全成熟的肠上皮细胞富含肌球蛋白的终末网处。大肠上皮细胞对半乳糖凝集素-3和半乳糖凝集素-4/6有强烈的免疫反应，但对半乳糖凝集素-2没有反应。前胃的复层鳞状上皮对半乳糖凝集素-3和半乳糖凝集素-7有免疫反应，但基底层缺乏半乳糖凝集素-3免疫反应性。在上皮细胞外，只有半乳糖凝集素-1定位于结缔组织、平滑肌和神经元细胞体中。半乳糖凝集素的亚型特异性定位表明其在宿主-病原体相互作用和上皮稳态（如肠道中的膜极化和运输）中起重要作用。
