New proteins as vascular biomarkers in primary open angle glaucomatous aqueous humor.

PURPOSE

The aim of this study was to investigate the expression level of several biomarkers in the in the aqueous humor of 14 patients with primary open angle glaucoma who underwent glaucoma surgery, and 11 nonglaucomatous normals who underwent cataract extraction surgery.

METHODS

The aqueous humor proteome of 25 patients was analyzed using an antibody microarray. Fourteen patients with uncontrolled intraocular pressure-despite profound therapeutic interventions-who underwent filtering procedures and 11 control subjects who underwent surgery for senile cataracts were included in the present study. Protein expression was evaluated using Cy3/Cy5 labeling, column purification, and hybridization on antibody-spotted glass microarrays. Fluorescent signals were detected by fluorescence laser scanning.

RESULTS

The levels of 13 proteins were significantly increased in the aqueous humor of glaucomatous patients compared with expression levels in healthy controls. One of the 13 proteins (ELAM 1) was involved in inflammation. Two of these proteins (apolipoprotein B and E) were involved in the delivery of cholesterol to cells. Five of the 13 proteins (myotrophin, myoblast determination protein 1, myogenin, vasodilator-stimulated phosphoprotein, and ankyrin-2) were involved in muscle cell differentiation and function. Three proteins (heat shock 60 kilodaltons (kDa) and 90 kDa proteins, and ubiquitin fusion degradation 1-like) were involved in stress response and the removal of damaged proteins; and two proteins (phospholipase C β and γ) were involved in signal transduction and neural development.

CONCLUSIONS

The expressions of these proteins in the aqueous humor of glaucomatous patients reflect the damage occurring in anterior chamber endothelia, mainly including the trabecular meshwork, which is the main structure of this ocular segment injured by glaucoma.