Abstract
Purpose: :
To evaluate the role of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP) in injured optic nerve in mouse model.
Methods: :
Three models of optic nerve injury were performed: meningeal fenestration and partial axotomy (MFA), partial meningotomy and axotomy (PMA), and optic nerve transection (ONT). Sections of the optic nerve were obtained from each model preoperatively and postoperatively, and immunostained with MMP-2, MMP-3, MMP-7, MMP-14 (N1, N2, La, Cb domain), VEGF and glial fibrillary acidic protein (GFAP). Transmission electron microscopy was used to evaluate the ultrastructure of the optic nerve in wild-type and MMP-2, -7, and collagen XVIII knock-out mice.
Results: :
Without injury, MMP-2, MMP-3, and MMP-14 only stained weakly at the meninge and perineuron on mouse optic nerve, while MMP-7 stained diffusely in the optic nerve with some colocalization of astrocyte. In injured models, MMP-7, MMP-14, VEGF increased expression in all three injury models. VEGF expression at the transection site was increased in ONT model. Histologically, the nerve bundles of the MMP-7 knock-out mice were irregular in shape and size and were loosely arranged when compared with the wild type mice.
Keywords: optic nerve • trauma • regeneration