Premium
Targeting Citrullination in the Injured Retina
Author(s) -
Wizeman John,
Nicholas Anthony,
Mohan Royce
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.717.15
Subject(s) - citrullination , vimentin , gliosis , glial fibrillary acidic protein , western blot , microbiology and biotechnology , retina , intermediate filament , pathology , blot , chemistry , biology , citrulline , immunohistochemistry , medicine , biochemistry , neuroscience , cell , cytoskeleton , arginine , amino acid , gene
Objective To define the contribution of citrullination on GFAP and vimentin in a traumatic eye injury model. Methods: An ocular alkali injury model of retinal gliosis was employed in mice. Retinas from injured mice were examined at different times by western blot or immunochemistry for expression of GFAP, vimentin and citrullinated proteins. Posterior eye‐cups from 7‐day injured mice were placed into explant culture to investigate effects of peptidyl arginine deiminase (PAD) inhibitor Cl‐amidine. Results: GFAP expression increases initially in the soluble extracts, starting as early as 1 hour after injury and continues over the 7‐day post‐injury period, followed by increased abundance of polymeric filaments in insoluble extracts. GFAP filament growth begins at the Muller glial end‐feet and advances towards the outer retina, showing punctate co‐staining for citrullinated precursors that become incorporated into vimentin and GFAP filaments from soluble pools. At later time points, these citrullinated protein species also become abundant in insoluble extracts. In posterior eye explant culture model from 7‐day injured eyes showing reactive gliosis, global increases in high molecular weight citrullinated proteins were detected. Cl‐amidine treatment strongly downregulates these hypercitrullinated proteins and high‐molecular weight citrullinated GFAP species. Conclusions GFAP appears to be a major target of hypercitrullination in this traumatic injury model of irreversible blindness because of its abundant overexpression. Our findings suggest that PADs are important targets for reversing pathological reactive gliosis. Supported by EY016782 and Solomon Endowed Chair Fund.