October 2007

 

CATARACT/ IOL

 

Ceramide levels may modulate age-related cataracts


 

 

A recent study suggests that age-related cataracts may be modulated by ceramide levels in the lens. Published in the September issue of Molecular Vision, the study was aimed at determining whether ceramide treatment contributes to reduced cell viability, increased apoptosis, caspase activation, and reactive oxygen species generation in lens epithelial cells Study author Abbas Samadi, Ph.D., Department of Biochemistry, A.T. Still University of Medical Sciences, Kirksville College of Osteopathic Medicine, Kirksville, MO, wrote that Cell viability was determined by the 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptotic cell death was determined by 4,6 diamidino-2-phenylindole (DAPI) nuclear staining, while quantitative DNA fragmentation was determined by specific determination of cytosolic mononucleosomes and oligonucleosome-bound DNA. In addition, the researcher determined Caspase-3/7 activation by using the Apo-ONE Assay and the detection of reactive oxygen species was achieved by a carboxy-2,7-dichlorofluorescein diacetate (carboxy-H2DCFDA) staining method and lipid peroxidation assay, Dr. Samadi wrote.

Results of the study showed C2-ceramide and C6-ceramide reduced primary bovine lens epithelial cell and human lens epithelial cell survival in a dose- and time-dependent manner. The effect of ceramide on cell viability was specific since C2-dihydroceramide, a chemically similar ceramide lacking four to five double-bonds, did not adversely affect lens epithelial cell viability, the study author wrote. The release of endogenous natural ceramides by treatment of lens epithelial cells with bacterial sphingomyelinase reduced cell viability, while Ceramide-induced apoptosis in lens epithelial cells was determined by nuclear appearance and DNA fragmentation. Apoptosis was induced by exogenous C2-ceramide in a dose-dependent and time-dependent manner and ceramide-mediated apoptosis of lens epithelial cells was associated with caspase-3/7 activation. C2-ceramide treatment resulted in reactive oxygen species generation.

Dr. Samadi suggested in his conclusion that ceramide reduced cell viability and increased apoptosis in a dose-dependent and time-dependent manner in lens epithelial cells. Ceramide-induced oxidative stress suggests that age-related cataracts may be modulated by ceramide levels in the lens, he wrote.

Source: EyeWorld News Service

Ceramide levels may modulate age-related cataracts Ceramide levels may modulate age-related cataracts
Ophthalmology News - EyeWorld Magazine
283 110
283 110
,
2016-07-26T13:36:19Z
True, 10