We recently discovered that the drug U18666A, an inhibitor of cholesterol synthesis, when given at a low dose to neonatal rats can lead to development of cataracts of the lens of the eye. This new model may offer some advantages over existing models, since the drug is well tolerated by the rat, the cataracts are rapidly induced, they appear primarily to involve the nucleus of the lens and to some extent the cataracts appear reversible. Preliminary work in our laboratory indicates that both lens lipids and proteins are altered by U18666A and, in particular, the observed changes in proteins are similar to those reported to occur in human cataracts of senile origin. Specifically, in U18666A induced cataractous lens the relative content of soluble proteins decrased in insoluble proteins increase. The overall objectives of the proposed research are to clearly describe this new model of cataracts and to determine the basic mechanism of cataractogenesis. More specifically, in the proposed studies we will examine the morphology of the eye during cataract development and reversal, measure and correlate changes in lens lipids and proteins, and measure synthesis de novo of sterols and proteins in normal and cataractous lenses. Standard histological technics using a variety of stains will be used for the studies of morphology. Lipids extracted from the lens will be separated by thin-layer chromatography and subsequently quantiated by gas-chromatography and colorimetric assays. Proteins will be fractionated and identified by Sephadex G-200 and DEAE cellulose chromatography and SDS and alkaline urea polyacrylamide-gel-electrophoresis. By correlating the sequence of changes in lens lipids versus proteins during cataract development and reversal we should be able to critically evaluate the relative importance of effects upon lipids versus proteins in explaining the etiology of the cataracts induced by U18666A. The proposed project promises to develop a new model for the study of cataracts and will provide new information on the biochemistry of cataracts which could contribute to a greater understanding of human lens disorders.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY002568-08
Application #
3256866
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1978-08-01
Project End
1986-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
8
Fiscal Year
1985
Total Cost
Indirect Cost
Name
A.T. Still University of Health Sciences
Department
Type
Schools of Osteopathy
DUNS #
City
Kirksville
State
MO
Country
United States
Zip Code
63501
Cenedella, Richard J (2009) Cholesterol synthesis inhibitor U18666A and the role of sterol metabolism and trafficking in numerous pathophysiological processes. Lipids 44:477-87
Cenedella, Richard J; Sexton, Patricia S; Brako, Lawrence et al. (2007) Status of caveolin-1 in various membrane domains of the bovine lens. Exp Eye Res 85:473-81
Cenedella, Richard J; Neely, Amanda R; Sexton, Patricia (2006) Multiple forms of 22 kDa caveolin-1 alpha present in bovine lens cells could reflect variable palmitoylation. Exp Eye Res 82:229-35
Cenedella, Richard J; Sexton, Patricia S; Krishnan, Kathiresan et al. (2005) Comparison of effects of U18666A and enantiomeric U18666A on sterol synthesis and induction of apoptosis. Lipids 40:635-40
Cenedella, Richard J; Neely, Amanda R; Sexton, Patricia (2005) Concentration and distribution of ubiquinone (coenzyme Q), the endogenous lipid antioxidant, in the rat lens: effect of treatment with simvastatin. Mol Vis 11:594-602
Cenedella, Richard J; Jacob, Robert; Borchman, Douglas et al. (2004) Direct perturbation of lens membrane structure may contribute to cataracts caused by U18666A, an oxidosqualene cyclase inhibitor. J Lipid Res 45:1232-41
Sexton, Patricia S; Neely, Amanda R; Cenedella, Richard J (2004) Distribution of caveolin-1 in bovine lens and redistribution in cultured bovine lens epithelial cells upon confluence. Exp Eye Res 78:75-82
Cenedella, Richard J; Kuszak, Jerome R; Al-Ghoul, Kristin J et al. (2003) Discordant expression of the sterol pathway in lens underlies simvastatin-induced cataracts in Chbb: Thom rats. J Lipid Res 44:198-211
Cenedella, R J (2001) Specific labeling of lens aldehyde dehydrogenase class 1 from (3)H-cholesterol or its derivatives. Ophthalmic Res 33:210-6
Zhu, X L; Sexton, P S; Cenedella, R J (2001) Characterization of membrane steroid binding protein mRNA and protein in lens epithelial cells. Exp Eye Res 73:213-9

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