TY - JOUR
T1 - Aquaporins in complex tissues
T2 - Distribution of aquaporins 1-5 in human and rat eye
AU - Hamann, Steffen
AU - Zeuthen, Thomas
AU - La Cour, Morten
AU - Nagelhus, Erlend A.
AU - Ottersen, Ole Petter
AU - Agre, Peter
AU - Nielsen, Søren
PY - 1998/5
Y1 - 1998/5
N2 - Multiple physiological fluid movements are involved in vision. Here we define the cellular and subcellular sites of aquaporin (AQP) water transport proteins in human and rat eyes by immunoblotting, high-resolution immunocytochemistry, and immunoelectron microscopy. AQP3 is abundant in bulbar conjunctival epithelium and glands but is only weakly present in corneal epithelium. In contrast, AQP5 is prominent in corneal epithelium and apical membranes of lacrimal acini. AQP1 is heavily expressed in scleral fibroblasts, corneal endothelium and keratocytes, and endothelium covering the trabecular meshwork and Schlemm's canal. Although AQP1 is plentiful in ciliary nonpigmented epithelium, it is not present in ciliary pigmented epithelium. Posterior and anterior epithelium of the iris and anterior lens epithelium also contain significant amounts of AQP1, but AQP0 (major intrinsic protein of the lens) is expressed in lens fiber cells. Retinal Muller cells and astrocytes exhibit notable concentrations of AQP4, whereas neurons and retinal pigment epithelium do not display aquaporin immunolabeling. These studies demonstrate selective expression of AQP1, AQP3, AQP4, and AQP5 in distinct ocular epithelia, predicting specific roles for each in the complex network through which water movements occur in the eye.
AB - Multiple physiological fluid movements are involved in vision. Here we define the cellular and subcellular sites of aquaporin (AQP) water transport proteins in human and rat eyes by immunoblotting, high-resolution immunocytochemistry, and immunoelectron microscopy. AQP3 is abundant in bulbar conjunctival epithelium and glands but is only weakly present in corneal epithelium. In contrast, AQP5 is prominent in corneal epithelium and apical membranes of lacrimal acini. AQP1 is heavily expressed in scleral fibroblasts, corneal endothelium and keratocytes, and endothelium covering the trabecular meshwork and Schlemm's canal. Although AQP1 is plentiful in ciliary nonpigmented epithelium, it is not present in ciliary pigmented epithelium. Posterior and anterior epithelium of the iris and anterior lens epithelium also contain significant amounts of AQP1, but AQP0 (major intrinsic protein of the lens) is expressed in lens fiber cells. Retinal Muller cells and astrocytes exhibit notable concentrations of AQP4, whereas neurons and retinal pigment epithelium do not display aquaporin immunolabeling. These studies demonstrate selective expression of AQP1, AQP3, AQP4, and AQP5 in distinct ocular epithelia, predicting specific roles for each in the complex network through which water movements occur in the eye.
KW - Cornea
KW - Lens
KW - Retina
KW - Uvea
KW - Water transporters
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U2 - 10.1152/ajpcell.1998.274.5.c1332
DO - 10.1152/ajpcell.1998.274.5.c1332
M3 - Article
C2 - 9612221
AN - SCOPUS:0031802879
SN - 0363-6143
VL - 274
SP - C1332-C1345
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
IS - 5 43-5
ER -