Abstract
Purpose: :
Perlecan, a large, multi-domain, heparan sulfate proteoglycan originally identified in basement membrane, interacts with extracellular matrix proteins, growth factors and receptors, and influences cellular signaling. We reported small eye balls and the thin of corneal epithelium in the eye of perlecan-null mice by transmission electron microscopic analysis last year in ARVO. This study was performed to elucidate the roles of perlecan in the corneal epithelium of mice by histochemical analysis.
Methods: :
The perlecan-null mice were generated as reported previously (Nat Genet. 23:354-8, 1999). We examined the 8week-old mice (Perlecan-null mice=5, control mice=5). The eyes of these mice were dissected and prepared for histological or molecular analysis. 3-µm paraffin sections were made from the perlecan-null mice and control mice. The specimens were stained with hematoxylin-eosin. For transmission electron microscopic analysis, tissues were fixed in 2.5% glutaraldehyde in Sorensen buffer, postfixed in osmium tetroxide. Subsequently, the corneal thickness measured under a microscope. We performed immunostaing of TUNEL, Ki67, p-63 and Cytokeratin12.
Results: :
The ratio of the epithelial cell layer thickness to the full cornea thickness was 22.67±5.25%(mean±SD) in the perlecan-null mice group and 30.34±3.25% in the control group. The perlecan-null mice group showed the significant thinning of the corneal epithelium (p=0.0317). Immunostainng of Ki67, cell proliferation marker, in the perlecan-null group showed the significant reduction of the staining of nuclei(p=0.0343). On the other hand, immunostaing of TUNEL, p-63, and Cytokeratin12 showed no significant differences between the groups.
Conclusions: :
Perlecan may affect the cell proliferation status in the corneal epithelium.
Keywords: cornea: epithelium • proteoglycans/glycosaminoglycans