Abstract
Purpose: :
Glaucoma leads to apoptosis of retinal ganglion cells (rgc). Previous studies show changes in the autoantibody profiles against retinal antigens of primary open angle glaucoma (POAG) patients in comparison to healthy controls such as antibodies (AB) against GFAP or14-3-3. The aim of this study was to detect if the serum of POAG patients as well as its AB’s has an effect on the protein expression profiles of rgc.
Methods: :
These studies were performed with the rgc line RGC5 and the neuroretinal cell line R 28. The cells were incubated with POAG serum, POAG serum after AB removal with protein G beads as well as serum from healthy people for 24 or 48h. The protein profiles of the cell lysates were measured with Seldi-Tof-MS and Maldi-Orbitrap-MS.
Results: :
We detected significant changes of the protein profiles of both RGC5 and R28 cells after incubation with POAG serum. The analysis of discriminance showed highly significant changes in the protein profiles of the R28 cells after incubation with POAG serum such as the biomarker at 9192Da (p < 0.001) or 12390Da (p < 0.001). The calculated Mahalanobis distances revealed a significantly changed cell reaction after the incubation with AB free POAG serum (p < 0.03). In RGC5 cells 39 significant protein biomarkers were detected in the cells incubated with POAG serum. The quantification of the measured peptide-fragments showed an up-regulation of proteins involved in the intracellular apoptosis pathways such as the protein 14-3-3 eta in cells incubated with POAG serum (18 fold).
Conclusions: :
The treatment of rgc with POAG serum provokes a significantly changed protein expression of the cells. The up-regulation of proteins involved in intracellular regulatory processes such as 14-3-3 in cells incubated with POAG serum could be a result of changes in the natural autoimmunity of glaucoma patients showing a down-regulation of 14-3-3 AB. The altered reaction of the cells after AB removal of the POAG serum underlines the hypothesis that the AB’s have an influence on the protein expression of rgc and possibly have an influence in the pathogenesis of glaucoma.
Keywords: ganglion cells • proteomics