Genetic, Age and Light Mediated Effects on Retinal Crystallins.

Abstract

Abstract: : Purpose: To determine possible relationships between retinal crystallin protein expression and the time course of experimental or genetic retinal degenerations in animal models of retinal disease. Methods: Normal Sprague–Dawley, Royal College of Surgeons (RCS) and transgenic rats expressing rhodopsin mutations were reared in dim cyclic light for 20–60 days. Some animals were exposed to intense visible light for 8 hours and others were used for ROS isolations. 2D–gel electrophoresis was used to profile retinal and ROS proteins obtained from 3–8 normal and mutant rats at various ages. α, ß and γ crystallins were detected by Western analysis with class specific or individual crystallin antibodies and identified from comparative 2D–gel patterns of lens proteins and from mass spectroscopy. Results: In normal rats, retinal crystallin profiles are different from those of lens or RPE. Crystallins were also found to be present in purified ROS. Some classes of crystallins increased with age or were altered by intense light exposure. In genetic models of retinal degeneration, increased levels of crystallin protein immunoreactivity appeared to correlate with the onset and time course of photoreceptor loss as determined by retinal DNA measurements. Conclusions: 2D–gels and western analysis of ocular tissue proteins and crystallins indicate that retinal samples were largely uncontaminated by lens or RPE. Different crystallin protein expression patterns were found in genetic models of retinal disease as a function of age and degeneration. Our data suggests that photoreceptor cell degeneration may lead to an increase in the expression or post–translational processing of crystallins which appear to be related to the form and severity of retinal degeneration. CR: None. Support: NIH EY–01959 & M. Petticrew, Springfield, OH (DTO); NIH EY06603 and EY014239 (JWC).

Keywords: crystallins • retinal degenerations: hereditary • proteomics