Post-translational modification of crystallins in vitreous body from experimental autoimmune uveitis of rats

Abstract

Experimental autoimmune uveitis (EAU) is a well-known animal model of posterior uveitis that is one of the major causes of blindness. EAU could be induced in susceptible animals (i.e., Lewis rat) by immune reactions using evolutionarily conserved retinal proteins, such as interphoto-receptor retinoid binding protein (IRBP), or epitaphs of the protein. First, we prepared the following four test groups that subsequently increased or decreased inflammation. (1) Normal control group, (2) IRBP-induced uveitis group, (3) Hemin-treated uveitis group, and (4) Sn(IV) protoporphyrin IX dichloride (SnPP)treated uveitis group. Second, in the vitreous bodies of Lewis rats, the infiltrated proteins were analyzed using two-dimensional electrophoresis (2-DE), MALDI-TOF/MS, and Micro LC/LC-MS/MS analysis. Finally, Western blotting was applied to confirm the relative amount of crystallins and phosphorylation sites of (alpha B-crystallin. Thirty spots were identified in vitreous bodies, and 27 of these spots were members of the crystallin family. Unlike beta A4- and B2-crystallins (that were significantly increased without truncation), (alpha A- and B-crystallins were only truncated in EAU vitreous body. Taken as a whole, in the rat EAU model, we suggest that post-translational truncations of (alpha A- and alpha B-crystallins, phosphorylation of alpha B-crystallin, and new production of beta A4- and beta B2-crystallins are intercorrelated with uveitis progression and inflammatory responses.