Development and expression of amyloid-beta peptide 42 in retinal ganglion cells in rats.

摘要

The previous studies have shown that Amyloid-beta peptide (Abeta) was mainly found in neurons of neurodegenerative diseases, such as Alzheimer's disease (AD) and glaucoma and little is known about its expression in normal nerve cells. The aim of the present study was to investigate the expression of amyloid-beta peptide 42 (Abeta-42) in retinal ganglion cells of the postnatal rats. Rats were divided into seven experimental groups: 3, 6, 13, 15, 25, 60, and 90 days postnatal groups. Rats from 15 and 25 days postnatal groups were further divided into light-exposure and non light-exposure group. Cryosections or flat-mounted retinas of rat eyes were used for testing Abeta-42 by immunocytochemistry staining. Abeta-42 expression was not observed in rats within 13 days after birth, but was easily detectable in all groups of rats over 15 days after birth. In addition, the expression of Abeta-42 in retina was increasing as the rats got older, reached to highest level in 60 days after birth. Furthermore, the expression of Abeta-42 was not detected in rats kept under dark indicating that light is required for the expression of Abeta-42 in retina. This is the first report showing that normal retinal ganglion cells express Abeta-42, and that the expression of Abeta-42 in retinal ganglion cells requires the exposure to light. These data suggest that Abeta-42 may play a important role in vision development.