Abstract
Purpose: :
Retinal edema is a common complication of ischemic and inflammatory ocular diseases. It is known that the swelling of Muller cells contributes to the pathogeneses of retinal edema. Aquaporins (AQPs) are a transmembrane protein family of at least 12 homologous water channels, and AQP4 is expressed in the muller cells in the retina. To investigate whether AQP4 is involved in the retinal edema accompanied by inflammation, we studied the effects of lipopolysaccharide of AQP4 expression in the muller cells of the retina.
Methods: :
Muller cells were prepared by dissociating the retinas of a neonatal rat, then culturing these tissues. The purity of the cultures was evaluated by immunocytochemical staining with anti–vimentin antibody and anti– glial fibrillary acidic protein antibody. Primary cell cultures or cells of passages 1–3 were used for experiments. Total protein was isolated and the expression of AQP4 in Muller cells induced by lipopolysaccharide was analysed using western blotting.
Results: :
The cultures reached confluence within 3–7 days to become a monolayer of epithelioid–like cells. Immunocytochemical staining showed that the cells were positive for vimentin and glial fibrillary acidic protein, retinal glial cell markers. Western blot results showed that lipopolysaccharide induced AQP4 expression in a concentration– and time–dependent manner.
Conclusions: :
These findings suggest that the induction of AQP4 in Muller cells may participate in the development and amelioration of retinal edema accompanying inflammation by increasing water permeability between the blood and retina.
Keywords: retinal glia • Muller cells • inflammation