Abstract
Purpose: :
Several studies reported that inactivation of the Rho/ROCK signaling pathway promoted central nervous system axon regeneration. The purpose of current study is to examine the distribution of ROCK2 in TNF-α-induced optic nerve degeneration.
Methods: :
Rats were euthanatized at 1 day, or 1 or 2 weeks after PBS or TNF-α (10 ng) intravitreal injection. Levels of ROCK2 protein in the optic nerve and retina were evaluated by Western blot analysis. Localization and distribution of ROCK2 in optic nerve cross section as well as transverse section were determined by immunohistochemistry.
Results: :
Western blot analysis showed a significant increase in ROCK2 protein levels in the optic nerve at 1 day after TNF-α injection. Immunohistochemical double labeling showed substantial co-localization of ROCK2 and vimentin in the optic nerve as well as retina. There was a decrease in immunoreactivity of neurofilament in the optic nerve 2 weeks after TNF-α injection. Abundant immunoreactivity of ROCK2 was observed in post-laminar portion and this area had an increased immunoreactivity of vimentin after TNF-α injection.
Conclusions: :
Increase of ROCK2 in the optic nerve may be involved in increased vimentin activity around axons in TNF-α-induced optic nerve degeneration.
Keywords: neuro-ophthalmology: optic nerve • optic nerve • glia