X-Message-Number: 27543
From: "Basie" <>
Subject: Low Cholesterol causes Cataract Development
Date: Sat, 28 Jan 2006 21:10:50 -0500

Low Cholesterol Cues Cataract Development
Cataracts are a leading cause of blindness worldwide. Using a rat model of 
cataract formation, Masayuki Mori and researchers at Shinshu University 
Graduate School of Medicine in Japan have now found a link between cataracts 
and cholesterol.

The study, appearing online on January 26 in advance of print publication in 
the February 2006 issue of the Journal of Clinical Investigation reports 
that a primary genetic defect in cataractogenesis is combined mutation of 
the lanosterol synthase (Lss) and farnesyl diphosphate farnesyl transferase 
1 (Fdft1) genes, both of which function in cholesterol biosynthesis. 
Cataractous rats with these 2 gene mutations demonstrated reduced 
cholesterol levels in the eye lens and cerebral cortex, compared to 
wild-type rats. The researchers also identified a problem with specialized 
cells of the eye lens, known as epithelial cells.

These cells, which require cholesterol for proper development, normally form 
a thin, single layer across the lens and are responsible for maintaining the 
transparency of the lens. In cataracts, these cells fail to mature normally, 
and Mori's group now shows that epithelial cells of cataractous rats with 
mutations in Lss and Fdft1 also mature abnormally, suggesting that the 
defect in cholesterol synthesis alters proliferation of these cells and 
contributes to the lens becoming opaque.

The results could have clinical impact in patients taking 
cholesterol-lowering medications or in individuals with inborn defects in 
cholesterol synthesis.


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