Histamine, ZO-1 and increased blood-retinal barrier permeability in diabetic retinopathy

Trans Am Ophthalmol Soc. 1995;93:583-621.

Abstract

Purposes: First, to develop an improved retinal capillary endothelial cell culture system which exhibits some of the physiologic features of the bloodretinal barrier; second, to use this model to determine how histamine and chemical conditions of diabetes effect expression of the tight junction protein, ZO-1; and third, to discuss application of the Henle-Koch postulates to the problem of diabetic retinopathy.

Methods: Bovine retinal capillary endothelial cells were exposed to varying serum and growth factor concentrations, as well as astrocyte-conditioned medium, in order to establish a model of the blood-retinal barrier. Cells were also exposed to varying concentrations of histamine, and of insulin and glucose. The expression of ZO-1 tight junction protein was determined by immunocytochemistry and immunoblotting.

Results: Modified concentrations of growth factors reduced endothelial cell proliferation, without reducing viability. Astrocyte conditioned medium increased ZO-1 protein content. Histamine reduced ZO-1 protein content. Both high glucose (20mM) and low insulin (10(-12)M) reduced ZO-1 protein content compared to control conditions (5mM glucose and 10(-9) M insulin).

Conclusions: Control of culture conditions results in a more physiologic in vitro model of the blood-retinal barrier. Soluble factors from astrocytes promote tight junction formation. Both histamine and chemical conditions of diabetes diminish tight junction formation. These factors may mediate blood-retinal barrier breakdown in diabetic retinopathy. Henle-Koch postulates for diabetic retinopathy are presented.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Astrocytes / cytology
  • Blood-Retinal Barrier*
  • Capillaries
  • Capillary Permeability / physiology*
  • Cattle
  • Cell Division / drug effects
  • Cells, Cultured
  • Culture Media, Conditioned / pharmacology
  • Diabetic Retinopathy / etiology
  • Diabetic Retinopathy / physiopathology*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism*
  • Fluorescent Antibody Technique
  • Glucose / pharmacology
  • Histamine / pharmacology*
  • Humans
  • Hypoglycemic Agents / pharmacology
  • Immunoblotting
  • Insulin / pharmacology
  • Membrane Proteins / biosynthesis*
  • Phosphoproteins / biosynthesis*
  • Rats
  • Rats, Sprague-Dawley
  • Retinal Vessels / cytology
  • Retinal Vessels / drug effects
  • Retinal Vessels / metabolism
  • Zonula Occludens-1 Protein

Substances

  • Culture Media, Conditioned
  • Hypoglycemic Agents
  • Insulin
  • Membrane Proteins
  • Phosphoproteins
  • TJP1 protein, human
  • Tjp1 protein, rat
  • Zonula Occludens-1 Protein
  • Histamine
  • Glucose