Cholestanol induces apoptosis of corneal endothelial and lens epithelial cells.
OBJECTIVE
To determine whether cholestanol induces cornea endothelial and lens epithelial cell death in vitro.


METHODS
Cornea endothelial and lens epithelial cells were cultured in minimum essential media with 10% fetal bovine serum containing 10 microg/ml cholesterol in ethanol, 10 microg/ml cholestanol in ethanol, or 1% ethanol. These cells, stained using the terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) method, were analyzed by laser cytometer. The activities of ICE and CPP32 proteases in cells were also measured.


RESULTS
Both cornea endothelial and lens epithelial cells cultured with 10 microg/ml cholestanol showed a significant loss of viability. The nuclei of these cells cultured with 10 microg/ml cholestanol were more frequently stained than those exposed to 10 microg/ml cholesterol or 1% ethanol. Quantitative analysis of apoptotic DNA fragmentation confirmed that the cholestanol induced apoptosis of these cells in a time-dependent manner. The activities of interleukin-1beta-converting enzyme (ICE) and CPP32 proteases for cells cultured with 10 microg/ml cholestanol were significantly higher than those observed in control cells.


CONCLUSIONS
In vitro, cholestanol was taken up by corneal endothelial cells and lens epithelial cells, an event that led to apoptosis of these cells.
Inoue
K
K
Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, The University of Tokyo, Japan.
Kubota
S
S
Tsuru
T
T
Araie
M
M
Seyama
Y
Y
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D004083:Cholestanol / Q000494:pharmacology*; D002784:Cholesterol / Q000494:pharmacology; D004247:DNA / Q000032:analysis; D010450:Endopeptidases / Q000378:metabolism; D004728:Endothelium, Corneal / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D020287:In Situ Nick-End Labeling; D007908:Lens, Crystalline / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D009419:Nerve Tissue Proteins / Q000378:metabolism
D053148:Caspase 3; D020169:Caspases; D004083:Cholestanol; D002784:Cholesterol; D004247:DNA; D010450:Endopeptidases; D009419:Nerve Tissue Proteins; C505410:Casp3 protein, rat