title: Expression of aquaporins in the retina of diabetic rats.
abstract: OBJECTIVE
  The development of retinal edema is the main reason of impaired vision in non-proliferative diabetic retinopathy. Water transport through aquaporins (AQPs) has been suggested to facilitate the development of ischemic edema in the retina. Here, we investigated whether experimental diabetic retinopathy in rats results in alterations of the AQP expression in the neural retina and retinal pigment epithelium (RPE).
  
  
  METHODS
  Experimental diabetes in rats was induced by a single intravenous injection of streptozotocin (65 mg/kg body weight). The gene expression of AQPs in tissues from control and diabetic rats was examined by real-time RT-PCR. Retinal cryosections were immunostained against AQP5, 6, and 9.
  
  
  RESULTS
  The total RNAs extracted from the neural retina and RPE contained gene transcripts for AQP0, 1, 3, 4, 5, 6, 8, 9, 11, and 12. Experimental diabetes was associated with an upregulation of AQP1 in the neural retina, and of AQP5, 9, 11, and 12 in the RPE. Furthermore, diabetes was associated with a downregulation of AQP6 and AQP11 in the neural retina, and of AQP0 in the RPE. AQP5 and AQP9 immunolabelings of the RPE were increased, and AQP6 labeling of the outer plexiform layer was decreased in retinal slices from diabetic rats in comparison to slices from control rats.
  
  
  CONCLUSIONS
  The data suggest that experimental diabetic retinopathy is associated with a complex pattern of alteration in the retinal AQP expression. These alterations might be involved in the adaptation of retinal cells to hyperglycemic conditions and the development and/or resolution of retinal edema.
authors.affiliation: Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany. hollbm@medizin.uni-leipzig.de
authors.forename: Margrit
authors.initials: M
authors.lastname: Hollborn
authors.forename: Sladjana
authors.initials: S
authors.lastname: Dukic-Stefanovic
authors.forename: Thomas
authors.initials: T
authors.lastname: Pannicke
authors.forename: Elke
authors.initials: E
authors.lastname: Ulbricht
authors.forename: Andreas
authors.initials: A
authors.lastname: Reichenbach
authors.forename: Peter
authors.initials: P
authors.lastname: Wiedemann
authors.forename: Andreas
authors.initials: A
authors.lastname: Bringmann
authors.forename: Leon
authors.initials: L
authors.lastname: Kohen
mesh_terms: D000818:Animals; D051402:Aquaporin 5 / Q000096:biosynthesis / Q000235:genetics; D051403:Aquaporin 6 / Q000096:biosynthesis / Q000235:genetics; D020346:Aquaporins / Q000096:biosynthesis / Q000235:genetics*; D003921:Diabetes Mellitus, Experimental / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D003930:Diabetic Retinopathy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D012313:RNA / Q000235:genetics*; D051381:Rats; D020318:Rats, Long-Evans; D060888:Real-Time Polymerase Chain Reaction; D012160:Retina / Q000378:metabolism* / Q000473:pathology
chemical_list: C496040:Aqp5 protein, rat; C496043:Aqp6 protein, rat; C491637:Aqp9 protein, rat; D051402:Aquaporin 5; D051403:Aquaporin 6; D020346:Aquaporins; D012313:RNA