Immunolocalization of tight junction proteins, occludin and ZO-1, and glucose transporter GLUT1 in the cells of the blood-nerve barrier.
Facilitated-diffusion glucose transporter GLUT1 is abundant in the blood-nerve barrier. To observe the relationship between glucose transfer across the barrier and the molecular architecture of the barrier, we examined the localization of GLUT1 and tight junction proteins, occludin and zonula occludens-1 (ZO-1), by immunofluorescence microscopy and immunogold electron microscopy in the rat sciatic nerve. GLUT1 was enriched at the whole aspects of the plasma membranes of the cells of the barrier: perineurial cells, and endothelial cells of the blood vessels in the endoneurium. These GLUT1-positive cells were also positive for occludin and ZO-1, both of which were localized at tight junctions. ZO-1 additionally was present in the GLUT1-negative cells not serving as the blood-nerve barrier. These observations suggest that occludin in the tight junctions and GLUT1 at the plasma membranes in the cells of the barrier may constitute a mechanism for the selective transfer of glucose across the barrier while preventing the non-specific flow of blood constituents.
Tserentsoodol
N
N
Department of Cell Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan.
Shin
B C
BC
Koyama
H
H
Suzuki
T
T
Takata
K
K
D000818:Animals; D002196:Capillaries / Q000737:chemistry / Q000648:ultrastructure; D002199:Capillary Permeability / Q000502:physiology; D005455:Fluorescent Antibody Technique; D051272:Glucose Transporter Type 1; D006168:Guinea Pigs; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D016253:Microscopy, Immunoelectron; D009004:Monosaccharide Transport Proteins / Q000032:analysis*; D062793:Occludin; D010525:Peripheral Nerves / Q000098:blood supply / Q000737:chemistry / Q000648:ultrastructure; D010750:Phosphoproteins / Q000032:analysis*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000098:blood supply / Q000737:chemistry / Q000648:ultrastructure*; D019108:Tight Junctions / Q000737:chemistry* / Q000648:ultrastructure; D062826:Zonula Occludens-1 Protein
D051272:Glucose Transporter Type 1; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D062793:Occludin; C568987:Ocln protein, rat; D010750:Phosphoproteins; C495679:Slc2a1 protein, rat; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein