Abstract
Purpose: :
Age-related cataract is defined as an opacification of the lens caused by alterations in the lens proteins. Metallothionein (MT) is known to increase at the transcriptional level as a response to oxidative stress and developing cataract. In this study we have determined similar changes to expression of αA- and γD-crystallin throughout the lens.
Methods: :
Protein distribution was visualized using immunohistochemistry (IHC) on frozen section of the central region of the lens. Lenses were obtained from several ZDF rats with and without diabetic cataracts, fixed in 4% paraformaldehyde over night, and stained with antibodies for MT, αA-, βB1- and γD-crystallin.
Results: :
Increased MT expression was found in the epithelium of cataract lenses, with no notable presence in non-cataract lenses. Expression of γD-crystallin was likewise increased in the epithelium as well as all throughout the lens fibers in cataractous lenses compared to controls. A smaller increase was observed for αA-crystallin in the epithelium and outer cortex regions, whereas no change was observed with βB1-crystallin
Conclusions: :
Diabetic cataract in rat lenses is marked by increased expression of MT in the epithelial cells, γD-crystallin and partly αA-crystallin expression in the epithelium and lens fibers.
Keywords: crystallins • immunohistochemistry • cataract