This project aims to understand the mechanism by which growth factors (GF) and their signal mediators control lens epithelial and fiber cell formation and metabolism, in order to characterize the mitogenesis, differentiation and growth processes that occur during lens development, aging and cataract formation. They have characterized an important signal transduction enzyme, phosphatidylinositol-3 kinase (PI-3K), that plays a vital role in cell proliferation, differentiation and in prevention of apoptosis. They have also found that treatment of lens epithelial cell with insulin and IGF-1 resulted in the tyrosine phosphorylation of the regulatory subunit of PI-3K and activation of the enzyme. This enzyme and some of its known downstream components are present in fully differentiated fiber cells. In addition, the protein tyrosine phosphorylation process, which is important in PI-3K mediated signal transduction, was found to be affected in lenses that developed cataract. They hypothesized that (1) activation of GF receptor mediated intracellular signaling pathways, particularly the products of PI-3K and of other downstream enzymes, regulates the metabolism of individual lens cells. (2) Disturbances in protein tyrosine phosphorylation and the PI-3K signaling cascade could be a contributing factor in cataract formation. Identification of pathway components will be accomplished by immunoprecipitation and Western immunoblotting. Lens organ culture will also be employed to induce cataract-related changes with PI-3K inhibitors.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY012701-04
Application #
6635682
Study Section
Visual Sciences A Study Section (VISA)
Program Officer
Liberman, Ellen S
Project Start
2000-06-01
Project End
2005-07-31
Budget Start
2003-06-01
Budget End
2005-07-31
Support Year
4
Fiscal Year
2003
Total Cost
$178,750
Indirect Cost
Name
Louisiana State University Hsc New Orleans
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
782627814
City
New Orleans
State
LA
Country
United States
Zip Code
70112