TRANSFORMING-GROWTH-FACTOR-BETA INDUCED PROTEIN, BETA-IG-H3, IS PRESENT IN DEGRADED FORM AND ALTERED LOCALIZATION IN LATTICE CORNEAL-DYSTROPHY TYPE-I

Lattice corneal dystrophy type I (LCDI) is an inherited autosomal domi nant local amyloidosis, restricted to the corneal stroma. Comparison o f electrophoretic profiles of normal and dystrophic corneas revealed a 42 kD protein, which was present only in dystrophic corneas. The N-te rminal sequence of this protein showed identity to transforming growth factor-beta induced gene product (beta IG-H3). A polyclonal antiserum was raised in chicken against a synthetic peptide identical to the N- terminal portion of beta IG-H3. On immunoblots, the antiserum stained the 42 kD band, and also a 68 kD band corresponding to the reported mo lecular weight of the intact beta IG-H3. In normal corneas, only the 6 8 kD band was present. Immunohistologically, the antiserum stained cor neal subepithelial regions, including subepithelial deposits, in dystr ophic corneas. In normal corneas, the staining was observed only in th e epithelium. These results may reflect the role of beta IG-H3 in extr acellular matrix construction and/or amyloid formation. (C) 1998 Acade mic Press.