Abstract
Purpose: :
The pathogenesis of glaucoma still is unknown. Next to elevated reactive oxygen species (ROS) found in retinal ganglion cells (rgc) of glaucoma patients previous studies have demonstrated significant changes in the pattern of autoantibodies against retinal antigens in the serum of glaucoma patients in comparison to healthy controls. The antibody (ab) against γ -synuclein showed a lower concentration in glaucoma patients. Changed levels of γ -synuclein also can be shown in other neurodegenerative diseases such as Parkinson’s disease or Morbus Alzheimer. Our aim was to detect if the γ -synuclein ab levels possibly have an effect on rgc’s, those cells affected by glaucoma.
Methods: :
The retinal ganglion cell line RGC-5 was cultured in 24 well plates. The cells were preincubated with different IgG γ -Synuclein ab (Santa Cruz) concentrations (0.005, 0.05, 0.1, 0.5,1,5 µg/ml) for 3h and stressed with 50µM H2O2 (1h) in order to create ROS and 20mM glutamat (24h) to induce apoptosis. Controls were incubated without ab. Cell viability was measured with crystal violet and ROS production with 2’,7’dichlorofluorescin diacetate.
Results: :
The ROS- production was significantly reduced up to 12% (p < 0.02) in those cells preincubated with 0.1 and 5µg/ml γ -synuclein ab in comparison to the stressed control cells. Furthermore a significant increase of viability (15%,p < 0.05) of cells stressed with H2O2 and incubated with different antibody levels (0,05; 0,1; 0,5; 1; 5µg/ml) as well as a highly significant increase of viability of the cells incubated with glutamate and different antibody levels (0,1 and 1 µg/ml) was detected(15%, p < 0.005).
Conclusions: :
We detected significant neuroprotective effects especially of the lower γ -synuclein ab concentrations on the cells stressed with different stress factors, e.g. lower ROS level as well as raised viability. Possibly the γ -synuclein ab helps to produce protective effects against stress factors such as ROS by modulating γ -synuclein and related pathways in the cells. When changes such as an decrease of ab concentration in the serum of glaucoma patients occurs, the misbalance of the natural autoimmunity could lead to weakening of these protective functions.
Keywords: ganglion cells • neuroprotection • cell survival