Abstract
Purpose:
To examine the relationship of p62 and Nmnat3 in high IOP-induced optic nerve degeneration.
Methods:
Eight-week-old male Wistar rats were received the combination of injection of india ink and laser treatment to trabecular meshwork. Transfection of Nmnat3 was performed with electroporation after intravitreal injection of DNA plasmid. Intravitreal injection of rapamycin (2 μl; 1 mM) was also performed. The expression of p62 in optic nerve was examined by immunoblotting. Localization of p62 and Nmnat3 in RGC-5 cell was evaluated by immunocytochemistry.
Results:
Immunoblotting showed that there was an increase in p62 protein level in optic nerve after IOP elevation compared to the control group and this increase was significantly inhibited by Nmnat3 transfection. Nmnat3 transfection alone significantly decreased p62 protein levels in the optic nerve compared with the basal level. Immunocytochemistry showed that p62 was colocalized with MitoTracker Red in starved RGC-5 cells. Substantial colocalization of Nmnat3 and p62 was observed in starved RGC-5 cells.
Conclusions:
p62 was present in mitochondria in starved RGC-5 cells. Mitochondrial Nmnat3 inhibits up-regulation of p62 in optic nerve in a hypertensive glaucoma rat model.
Keywords: 613 neuro-ophthalmology: optic nerve •
615 neuroprotection •
629 optic nerve