Detection of gender differences in rat lens proteins using 2-D-DIGE

The glass-like transparency of the human eye lens is achieved by the tight packing of abundant crystallin proteins. However, the precise role of the accessory non-crystallin proteins is not well understood. We have carried out 2-DE mapping of these proteins in rat lens. This showed the presence of the high molecular weight filamentous structural proteins spectrin, filensin, tubulin, vimentin, actin and phakinin as well as several forms of potential crystallin oligomers comprised of alphaA, betaB1, betaA1 and betaA4 chains. Other proteins that were present include, heat shock protein 71, WD repeat protein 1, and several enzymes including alpha-enolase, pyruvate kinase, transketolase and aldose reductase. 2-D-DIGE analysis revealed several expression differences between the lens proteomes of male and female rats. Female rat lenses contained lower levels of aldose reductase, increased proteolyic fragments of the structural proteins filensin, vimentin and phakinin and higher levels of potential alphaA, betaB1 and betaA1 crystallin oligomers. Taken together these findings suggest that there are potential differences in oxidative stress regulation between male and female rat lenses, which may have implications on susceptibility to cataract formation. Future studies aimed at elucidating pre-cataractic changes in the non-crystallin proteins described here may facilitate identification of novel markers involved in cataractogenesis.