Jejunal/kidney glucose transporter isoform (Glut-5) is expressed in the human blood-brain barrier.
Jejunal/kidney glucose transporter isoform (Glut-5) is expressed in the human blood-brain barrier.
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DOI：
10.1210/endo.132.1.8419132
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发表时间：
1993
期刊：
影响因子：
4.8
通讯作者：
G. Mantych;D. James;S. Devaskar
中科院分区：
文献类型：
--
作者：
G. Mantych;D. James;S. Devaskar
最近克隆的Glut-5，葡萄糖转运蛋白同种型，在人空肠和肾脏中表达。采用先前表征的针对衍生的人Glut-5肽的C-末端区域的多克隆抗体和Western印迹分析，在成人脑匀浆中检测到50-55千道尔顿的Glut-5蛋白。大脑中Glut-5蛋白的含量比成人肾脏中的水平低4倍。使用大脑和小脑切片的免疫组织化学分析表明，仅在一些Glut-1和因子VIII阳性脑微血管内皮细胞中存在Glut-5免疫反应性，血管内红细胞和白色血细胞呈阴性。当与全脑匀浆相比时，在分离的人大脑皮层微血管制备物中Glut-5的5倍富集与Glut-1的20倍富集证实了这种选择性定位模式。我们的结论是，谷氨酸-5是本地化的人脑微血管内皮细胞。与其他使用果糖的组织不同，其中Glut-5可以辅助果糖载体的作用，在果糖不用作底物的脑中，Glut-5可以单独转运葡萄糖。Glut-5与先前表征的脑内皮Glut-1和Glut-3一起的这种作用需要进一步阐明。
The recently cloned Glut-5, glucose transporter isoform, is expressed in human jejunum and kidney. Employing previously characterized polyclonal antibodies directed towards the C-terminus region of the derived human Glut-5 peptide and Western blot analysis, a 50-55 kilodalton Glut-5 protein was detected in adult human brain homogenates. The amount of Glut-5 protein in brain was 4-fold lower when compared to the levels in adult kidney. Immunohistochemical analysis using cerebral and cerebellar sections demonstrated Glut-5 immunoreactivity in only some of the Glut-1 and factor VIII-positive brain microvascular endothelial cells, the intravascular red and white blood cells being negative. This selective localization pattern was confirmed by the 5-fold enrichment of Glut-5 vs. a 20-fold enrichment of Glut-1 in an isolated human cerebral cortical microvascular preparation, when compared to whole cerebral homogenates. We conclude that Glut-5 is localized in the endothelial cells of human brain microvasculature. Unlike other fructose using tissues, where Glut-5 may subserve the role of a fructose carrier, in brain where fructose is not used as a substrate, Glut-5 may transport glucose alone. This role of Glut-5 in conjunction with the previously characterized brain endothelial Glut-1 and Glut-3 needs further elucidation.