Abstract
Abstract: :
Purpose: The resistance of lens epithelial cells to apotogenic stimuli during cataract surgery is the basis for secondary cataract. The objective of these studies was to determine the basis of this protection. We exposed a range of lens and non-lens human cell lines to the protein kinase C inhibitor staurosporine on a range of substrates (plastic and bovine lens capsule) and assessed their survival. This was correlated with chaperone proteins expressions levels. Methods: Survival of a range of human cell lines (wild type lens epithelial cells (H36LE2), adrenal carcinoma cells (SW13 vimentin-),breast epithelial cells (MCF7) and astrocytes (U373)) was quantified using a non-radioactive cell titer apoptogen assay on both plastic , untreated bovine lens capsule and heat-treated bovine lens capsules after 48h hours exposure to staurosporine at a concentration of 500nM. HSP70, HSP27, alphaA- and alphaB-crystallin expression levels were determined by immunoblot analysis of total cell extracts, soluble and insoluble fractions. Results: There was a marked difference in cell survival on the bovine lens capsule between the lens epithelial cell line (H36LE2) and some non-lens epithelial cell lines, with a much higher protection to staurosporine being conferred to the lens epithelial cell line compared to other cell lines. On the bovine lens capsule, this protection was associated with changes in chaperone proteins expression. Conclusions: The lens capsule confers protection to lens epithelial cells, but not to all non-lens cells. These data demonstrate the specific interaction between the lens capsule and the associated epithelial cells. This protection also seems to correlate with the ability of the cell line tested to express of alpha-crystallins, especially alphaA-crystallin.
Keywords: posterior capsular opacification (PCO) • cell death/apoptosis • chaperones