title: Characterization of glucose transporter isoforms in the adult and developing human eye.
abstract: The expression of glucose transporter isoforms (Glut 1, Glut 3, Glut 4, and Glut 5) in the human eye was investigated at various ages ranging between 8 weeks gestation (first trimester) and adult using Western blot and immunohistochemical analyses. Glut 1 and Glut 3 expression and cellular localization patterns were similar to those of human brain. Glut 1 (50-kilodalton protein) was expressed by epithelial cells (retinal pigmented epithelium, choroidal, iridial, and pars planus), which form the blood-eye barrier, retinal Mueller cells, the lens fiber cells, iridial microvascular endothelial cells, and to a lesser extent by the outer segments of the photoreceptor cells in the adult eye. This pattern was conserved throughout development and was evident as early as 8 weeks gestation. In addition, the endothelial cells of vitreous hyaloid vessels expressed Glut 1 at 8 weeks gestation. Glut 3 (50 to 55-kilodalton protein) immunoreactivity was observed only in the adult inner synaptic layer of the retina. Neither Glut 4 nor Glut 5 was expressed in any occular tissue at any age examined. These results suggest that Glut 1 is the main glucose transporter of the human eye and that it is ontogenically conserved. In contrast, Glut 3 is associated with selective neuronal processes, and its expression is developmentally altered.
authors.affiliation: Division of Neonatology, St. Louis University School of Medicine, Missouri.
authors.forename: G J
authors.initials: GJ
authors.lastname: Mantych
authors.forename: G S
authors.initials: GS
authors.lastname: Hageman
authors.forename: S U
authors.initials: SU
authors.lastname: Devaskar
mesh_terms: D000328:Adult; D000375:Aging / Q000378:metabolism; D015153:Blotting, Western; D002648:Child; D004727:Endothelium / Q000737:chemistry; D004730:Endothelium, Vascular / Q000737:chemistry; D004848:Epithelium / Q000737:chemistry; D005123:Eye / Q000737:chemistry / Q000196:embryology / Q000254:growth & development*; D005455:Fluorescent Antibody Technique; D005865:Gestational Age; D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D006801:Humans; D009004:Monosaccharide Transport Proteins / Q000032:analysis* / Q000378:metabolism; D009419:Nerve Tissue Proteins; D012160:Retina / Q000737:chemistry; D014018:Tissue Distribution
chemical_list: D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D009004:Monosaccharide Transport Proteins; D009419:Nerve Tissue Proteins; C495677:SLC2A1 protein, human; C495687:SLC2A3 protein, human