Mahraoui L, Rousset M, Dussaulx E, Darmoul D, Zweibaum A, Brot-Laroche E
Institut National de la Santé et de la Recherche Médicale, Unité 178, Villejuif, France.
Am J Physiol. 1992 Sep;263(3 Pt 1):G312-8. doi: 10.1152/ajpgi.1992.263.3.G312.
The human colon carcinoma cell line Caco-2 was used as an enterocyte model to study the expression of the facilitative glucose transporters GLUT-1 and GLUT-2, and of the putative hexose transporter GLUT-5, which are expressed specifically in the gut. Northern blots indicate that Caco-2 cells express GLUT-1 and GLUT-5 mRNAs but not the mRNA coding for the basolateral glucose transporter GLUT-2. The level of GLUT-5 mRNA is growth dependent, being detectable only in postconfluent differentiated cells. In addition, the expression of GLUT-5 increases with the number of cell passages and is approximately 10 times higher in later passages (passage 184) than in early ones (passage 26). With the use of polyclonal antibodies directed against the COOH-terminus of GLUT-5, indirect immunofluorescence and Western blotting indicate that GLUT-5 is mainly localized to the brush border of Caco-2 cells. GLUT-5 is also found to be associated with the brush border of epithelial cells from fetal and normal adult human small intestine, but is absent from the colon.
人结肠癌细胞系Caco-2被用作肠上皮细胞模型，以研究易化葡萄糖转运蛋白GLUT-1和GLUT-2以及假定的己糖转运蛋白GLUT-5的表达，这些转运蛋白在肠道中特异性表达。Northern印迹表明，Caco-2细胞表达GLUT-1和GLUT-5 mRNA，但不表达编码基底外侧葡萄糖转运蛋白GLUT-2的mRNA。GLUT-5 mRNA的水平依赖于生长，仅在汇合后分化的细胞中可检测到。此外，GLUT-5的表达随细胞传代次数增加，在后期传代（第184代）时比早期传代（第26代）高约10倍。使用针对GLUT-5羧基末端的多克隆抗体，间接免疫荧光和蛋白质印迹表明GLUT-5主要定位于Caco-2细胞的刷状缘。还发现GLUT-5与胎儿和正常成人小肠上皮细胞的刷状缘相关，但在结肠中不存在。
