Abstract
Purpose: :
To determine whether aberrant deimination due to over-expression of peptidyl arginine deiminase type 2 (PAD2) under a strong promoter results in optic nerve damage in C57BL/6J mice. Deimination refers to conversion of protein-bound arginine into citrulline.
Methods: :
Adenoviral and lentiviral vector constructs expressing PAD2 under the control of CMV promoter were prepared. The packaged viral particles were injected in the eyes of C57BL/6J mice (n= 10 each control GFP and PAD2 construct) eyes at 4-6 weeks of age. The optic nerve of control GFP construct and PAD2 construct infected mice euthanized at 5 months of age were subjected to imaging after staining with paraphenylenediamine (PPD) and silver staining on alternate sections. The deimination in the optic nerve was determined by modified immunostaining for modified anti-citrulline and by dot blot analysis. The research reported here was conducted in compliance with the ARVO Statement for the Use of Animals in Ophthalmic and Visual Research.
Results: :
The over-expression of PAD2 under the control of CMV promoter expressed either in adenoviral or lentiviral vector resulted in elevated deimination and damage to the optic nerve compared to controls. The elevated deimination was determined from quantitative area and intensity measurements in dot blots as well as in optic nerve sections. The damage to the optic nerve was assessed using PPD or silver staining sections by two independent observers.
Conclusions: :
Aberrant deimination may result in optic nerve damage in PAD2 over-expressors compared to controls in C57BL/6J mice.
Keywords: optic nerve • protein modifications-post translational • proteins encoded by disease genes