Abstract
Abstract: :
Purpose:In order to better characterize the composition of the scleral extracellular matrix, the expression of several members of the small leucine rich proteoglycan (SLRP) family was evaluated in the human sclera. Methods:Semi-quantitative RT-PCR analysis was performed on RNA isolated from human donor sclera using primers for decorin, PRELP (proline arginine rich end leucine-rich protein), fibromodulin, biglycan, chondroadherin, and lumican. Protein levels of some of these SLRPs were confirmed by western blot and immunohistochemical analyses. Results:All six of the SLRPs were expressed in the human sclera, with PRELP exhibiting the highest steady state mRNA levels, relative to that of the other SLRPs (p <0.001, ANOVA). Further analysis of PRELP by western blot analysis of scleral protein extracts indicated that PRELP contained a 42 kD core protein with short unsulfated keratan sulfate side chains. Immunostaining of frozen scleral sections demonstrated the presence of PRELP throughout the stroma with intense staining along the retinal border. Conclusion:These results suggest that SLRP proteoglycans are expressed at varying levels in the human sclera and confirm the presence of PRELP, fibromodulin, and chondroadherin in the human sclera.
Keywords: 529 proteoglycans/glycosaminoglycans • 574 sclera • 403 extracellular matrix