Abstract
Purpose: :
The effects of intravitreal triamcinolone acetonide on the alterations in retinal gene expression were determined in a rat model of central retinal vein occlusion (CRVO).
Methods: :
In one eye of adult Brown Norway rats (n=65), all retinal veins near to the optic disk were photocoagulated using a bluegreen argon laser. Untreated eyes served as controls. 1, 3, 7 and 14 days after CRVO induction we investigated the gene expression of factors which influence the development of vascular edema (VEGF-A, PEDF), of channels implicated in retinal osmohomeostasis (Kir4.1, AQP4, AQP1), and of the pro-inflammatory factors IL-1ß and IL-6. Neuroretina and retinal pigment epithelium (RPE) cells were investigated separately.
Results: :
CRVO induced a rapid transient upregulation of Vegfa, and a delayed upregulation of Pedf in the neuroretina. Further, in the neuroretina and RPE, CRVO induced strong, transient downregulation of Kir4.1, Aqp4, and Aqp1, and striking rapid upregulation of Il1ß and Il6. Intravitreal triamcinolone reversed the downregulation of Kir4.1 and accelerated the normalization of the upregulated expression of Il1ß and Il6.
Conclusions: :
The study showed that triamcinolone exerts anti-inflammatory effects in the ischemic retina by inhibitory effects on the gene expression of IL-1ß and IL-6, and may have neuroprotective effects via improvement of retinal potassium homeostasis.
Keywords: gene/expression • vascular occlusion/vascular occlusive disease • vascular endothelial growth factor