Increased plasma levels of 20S proteasome alpha-subunit in glaucoma patients: an observational pilot study

Several reports have shown that proteasome levels may change during pathological processes. Here we investigated whether altered gene expression of the alpha-subunit of 20S proteasomes in leukocytes of glaucoma patients at the level of mRNA, shown by us earlier, is reflected by the level of protein synthesis.

Western blot analysis was performed to determine the protein levels of the 20S proteasome alpha-subunit in leukocytes of 12 glaucoma patients (6 HTG and 6 NTG) and 6 healthy controls.

Plasma levels of the 20S proteasome alpha-subunit showed a 3.4+/-0.47 (mean+/-SD; p<0.0001) fold increase in glaucoma patients when compared to healthy controls. In addition, normal tension glaucoma patients revealed a more pronounced alpha-subunit expression (p<0.05) when compared to patients with high tension glaucoma.

During the pathological process of glaucoma, proteasome protein levels increase. This indicates that proteasome protein levels may be a diagnostic or eventually a prognostic marker for glaucomatous damage.