Repairing retinal damage

Certain diseases of the retinal degeneration — such as retinitis pigmentosa and age-related macular degeneration — are associated with mutations in components of the visual signaling cascade, leading to the apoptotic death of photoreceptor cells. Accumulation of ceramide has been implicated in the early phase of the apoptotic response in other cell types but its role in the photoreceptor cells apoptosis has been unclear. In the March 14 Science, Usha Acharya and colleagues at the National Cancer Institute–Frederick, Maryland, US, show that modulating the ceramide biosynthetic pathway can rescue photoreceptor degeneration in Drosophila (Science, 299:1740-1743, March 14, 2003).

Acharya et al. cloned the ceramidase gene and expressed it in the eye of Drosophila mutants. They observed that targeted expression of neutral ceramidase (a ceramide degradation enzyme) rescued retinal degeneration in arrestin and phospholipase C Drosophila mutants. Both genetic backgrounds modulated the endocytic machinery because they suppressed defects in a dynamin ...