Abstract
Purpose: :
Mitochondrial fission is a cellular response to stress and may play an important role in neuronal apoptosis in neurodegenerative disease. It is not known whether increased intraocular pressure, a risk factor for glaucoma, induces mitochondrial fission in retinal ganglion cells (RGC). The purpose of this study was to determine whether increased hydrostatic pressure induces mitochondrial fission in cultured retinal ganglion cells.
Methods: :
RGC–5 cells were differentiated with succinyl concanavalin A (50 µg/ml). Using a modified pressure chamber, 30 mmHg of pressure was applied to differentiated RGC–5 cells for 1, 2, and 3 days. RGC–5 cells were then labeled with MitoTracker Red and mitochondrial morphology was assessed by fluorescence microscopy.
Results: :
RGC–5 cells did not show mitochondrial fission up to 2 days of pressure. However, 3 days of pressure resulted in more than 80% of mitochondrial fission characterized by the conversion of tubular fused mitochondria into isolated small organelles. Non–pressurized control cells showed only 15% of mitochondrial fission at 3 days.
Conclusions: :
Elevated pressure induces mitochondrial fission in differentiated RGC–5 cells. Mitochondrial fission may provide a biomarker for RGC stress and may play an important role in pressure–induced RGC death.
Keywords: mitochondria • ganglion cells • intraocular pressure