Immunoelectron microscopic localization of decorin in aged human corneal and scleral stroma

Decorin is one of the major proteoglycans in corneal and scleral stroma. Since the distribution of decorin in the normal human eye has not been fully investigated, we examined its immunoelectron microscopic localization in aged human corneal and scleral stroma using anti-decorin antiserum and gold particle-conjugated secondary antibody. In the corneal stroma, decorin was located on the surface of collagen fibrils, on interfibrillar type VI collagen filaments and on dark cross-bands of long-spacing collagen which occurred in the aged human corneal stroma. In the scleral stroma where the banding pattern of D-periodic collagen fibrils was clearly observed, decorin was located on the surface of D-periodic collagen fibrils, chiefly on the d (XI) and e (IX, X) bands, and also on interfibrillar amorphous materials of moderate density which were labeled with anti-type VI collagen antiserum.