Localization of secreted protein acidic and rich in cysteine (SPARC) expression in the rat eye

Secreted protein acidic and rich in cysteine (SPARC) is a secreted glycopro tein protein which modulates cell shape and cell-matrix interactions and ha s been implicated in the regulation of angiogenesis, vascular permeability and cataract formation, In situ hybridization and immunohistochemical studi es for SPARC were performed to determine the cell and tissue distribution o f SPARC in rat eye. Studies demonstrated SPARC mRNA and protein colocalizat ion at all sites. In the retina SPARC mRNA and protein were localized predo minantly to the Muller and ganglion cells. Within the choroid, SPARC was fo und in vascular endothelial cells and fibroblasts; in the sclera SPARC was present in blood vessels and fibroblasts, SPARC was also present in the non -pigmented epithelial cells of the ciliary body, and in the epithelium of t he lens capsule and cornea, The demonstrated anatomical distribution of SPA RC in the rat eye is consistent with several of the biological functions as cribed to this matricellular protein and provides a rational basis for its examination in pathological conditions.