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

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 alphaB-crystallin. Thirty spots were identified in vitreous bodies, and 27 of these spots were members of the crystallin family. Unlike betaA4- and B2-crystallins (that were significantly increased without truncation), alphaA- 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 alphaA- and alphaB-crystallins, phosphorylation of alphaB-crystallin, and new production of betaA4- and betaB2-crystallins are intercorrelated with uveitis progression and inflammatory responses.

Identification of crystallin family proteins in vitreous body in rat endotoxin-induced uveitis: Involvement of crystallin truncation in uveitis pathogenesis.

Endotoxin-induced uveitis (EIU) is an animal model of acute ocular inflammation. To characterize the mechanism of EIU, we analyzed the infiltration of proteins in the vitreous bodies of rats with EIU and normal rats using 2-DE and micro LC/LC-MS/MS. Twenty spots were identified in vitreous bodies of rats. Eighteen of these spots were members of the crystallin family. The truncated form of beta A4- and beta B2-crystallin were predominant in normal vitreous bodies, but there were intact form of crystallins in lipopolysaccharide-injected rats with EIU. These results suggest that crystallin family proteins are the major group of proteins involved in uveitic vitreous and that C-terminal truncation of beta-crystallins may play a role in EIU-related disease progression.