Expression of Small Leucine-Rich Proteoglycans in the Developing Retina and Kainic Acid-Induced Retinopathy in ICR Mice

Abstract

ABSTRACT. The aim of this study was to determine the developmental changes of small leucine-rich proteoglycans (PGs), decorin, biglycan and fibromodulin, in ICR mouse retinas and to elucidate their role in the adult retina using kainic acid (KA)-induced retinal degeneration model. Retinas of prenatal, postnatal and adult mice were collected for histological and immunohistochemical staining to investigate the changes in distribution of these PGs. Decorin-and fibromodulin-immunostainings were diffusely distributed at prenatal and early postnatal stages and were stronger in the adult retina. However, biglycan was moderately distributed in the prenatal and early postnatal stages and was faint in the adult retina. Retinas were collected at 1, 3 and 7 days after intravitreal injection of KA. Retinas of KA injected eyes underwent shrinkage accompanied by serious damage in the inner layers. Decorin and fibromodulin were upregulated in the inner retinal layers of KA-injected eyes compared to the normal ones. Our results suggest that decorin and fibromodulin play key roles in retinal differentiation, and contribute to the retinal damage and repair process. However, biglycan may have no or only a limited role in the mouse retinal development or repair process.KEY WORDS: biglycan, decorin, fibromodulin, kainic acid, retinal development and damage.

Small leucine rich proteoglycan family regulates multiple signalling pathways in neural development and maintenance

“…; Ali et al . ). Their high importances in the corneal development has been demonstrated by analyses of their gene knockout animals.…”

“…Indeed, some SLRPs are very highly expressed in these ocular tissues. Fibromodulin, keratocan and lumican, which all contain KS side chains, are highly expressed in both differentiating cornea and the adult cornea and have been shown to be involved in the development and maintenance of corneal transparency (Hart 1976;Cornuet et al 1994;Tanihara et al 2002;Chen et al 2010;Ali et al 2011). Their high importances in the corneal development has been demonstrated by analyses of their gene knockout animals.…”

UV-induced retinal proteome changes in the rat model of age-related macular degeneration

“…Small leucine-rich proteoglycans decorin, biglycan, fibromodulin and lumican bind collagen type I and regulate collagen fibril structure. In mice models with kainic acidinduced retinal degeneration, loss of inner retinal cells occurred accompanied by strong immunostaining for decorin and fibromodulin across the retina, while immunostaining for biglycan was weak in both the normal retina and the retina after KA injection [32]. The same study suggests that decorin and fibromodulin play key roles in retinal differentiation, and contribute to the retinal damage and repair process, while biglycan may have no or only a limited role in the mouse retinal development or repair process [32].…”

“…In mice models with kainic acidinduced retinal degeneration, loss of inner retinal cells occurred accompanied by strong immunostaining for decorin and fibromodulin across the retina, while immunostaining for biglycan was weak in both the normal retina and the retina after KA injection [32]. The same study suggests that decorin and fibromodulin play key roles in retinal differentiation, and contribute to the retinal damage and repair process, while biglycan may have no or only a limited role in the mouse retinal development or repair process [32]. Ali et al detected diffuse distribution of biglycan in the retina and optic nerve with intense staining in nervefiber rich layers in postnatal and adult mice [33].…”

Retinal Ultrastructural and Microvascular Defects in Decorin Deficient (Dcn −/−) Mice

“…In the retina, Dcn plays a key role as a neurotrophic factor during retinal differentiation [5], and localizes to nerve fiber layer and ganglion cell layer in the mature retina [6]. Upon retinal injury in mice, Dcn was shown to be highly upregulated in the inner retinal layers [7], while treatment with decorin was shown to improve vitrectomy outcome in rabbits with proliferative vitreoretinopathy [8], and prevent loss of tight junctions in human retinal pigmented epithelial cells under hyperglycemic and hypoxia stress [9]. Taken together, results indicate Dcn to be actively involved in retinal repair.…”