Age-related changes in the water-soluble lens protein composition of Wistar and accelerated-senescence OXYS rats

[摘要] Purpose: To determine the age-relatedand the cataract-specific changes in the crystallin composition inlenses of accelerated-senescence OXYS (cataract model) and Wistar(control) rats. Methods: The water soluble (WS) andinsoluble (WIS) fractions of the lens proteins were separated; theidentity and relative abundance of each crystallin in WS fraction weredetermined with the use of two-dimensional electrophoresis (2-DE) andMatrix-Assisted Laser Desorption Ionization – Time Of Flight(MALDI-TOF) mass spectrometry. All statistical calculations wereperformed using the software package Statistica 6.0 by factordispersion analysis (ANOVA/MANOVA) and Newman-Keuls post-hoc test forcomparison of group mean values. Results: The WIS protein contentincreased significantly in the aged animal lenses; the WIS/WS ratioincreases in approximately 8 times to the age of 62 weeks. Theinterstrain difference was insignificant in this experiment. 2-DE mapsof the young rat lenses (3 weeks) showed single spots for each lensprotein while in older lenses (12 and 62 weeks) each crystallin waspresented by several spots. The abundance of γA-γF-crystallins in WSfraction significantly decreases with age. A significant increase inthe percentage abundance was also found for α-crystallins andβB2-crystallin from 3 to 12 weeks. The major differences between Wistarand OXYS lenses are the faster decay of the content ofγA-γF-crystallins in OXYS lenses, and the significant decrease ofunmodified αA-crystallin abundance in old OXYS lenses. Conclusions: The presented resultsdemonstrate that the increase of the water-insoluble (WIS) proteinfraction is rather age-specific than cataract-specific phenomenon. Themajor age-related changes in WS protein composition are the fastinsolubilization of γ-crystallins, and the increase of αB- andβB2-crystallin abundance. The main interstrain differences, which couldbe attributed to the cataract-specific processes, are the faster decayof the content of γ-crystallins and the significant decrease ofunmodified αA-crystallin abundance in the OXYS lenses.

[学科分类] 生物化学/生物物理