Distribution of thrombospondin-4 in the bovine eye

Abstract

Purpose. The purpose of this study was to analyze the distribution of thrombospondin-4 (TSP-4) in the bovine eye. Methods. Anterior and posterior segments of the bovine eyes were sectioned and stained by the indirect immunofluorescence method with an anti-TSP-4 antibody. The tissues were analyzed by reverse-transcription-polymerase chain reaction (RT-PCR) to determine where the TSP-4 mRNA is produced. Results. Immunohistochemical staining for TSP-4 indicated the presence of TSP-4 in the cornea (epithelium, basement membrane, and keratocytes), conjunctiva (epithelium and stroma), aqueous ducts, sclera, iris (stroma), ciliary processes and muscle, trabecular meshwork, Bruch’s membrane, retina, lamina cribrosa, and optic nerve, and in all blood vessel walls. TSP-4 mRNA was expressed by the cells in all structures. Conclusions. TSP-4 is widely distributed in the bovine eye where it may play a role in the functions of basement membranes in various tissues. It is abundant in the trabecular and uveo-scleral pathways and may play a role in the regulation of aqueous outflow resistance.