Lectin binding to injured corneal endothelium mimics patterns observed during development

Abstract

Fluorochrome conjugated lectins were used to observe cell surface changes in the corneal endothelium during wound repair in the adult rat and during normal fetal development. Fluorescence microscopy of non-injured adult corneal endothelia incubated in wheat-germ agglutinin (WGA), Concanavalin A (Con A), and Ricinus communis agglutinin I (RCA), revealed that these lectins bound to cell surfaces. Conversely, binding was not observed for either Griffonia simplicifolia I (GS-I), soybean agglutinin (SBA) or Ulex europaeus agglutinin (UEA). Twenty-four hours after a circular freeze injury, endothelial cells surrounding the wound demonstrated decreased binding for WGA and Con A, whereas, RCA binding appeared reduced but centrally clustered on the apical cell surface. Furthermore, SBA now bound to endothelial cells adjacent to the wound area, but not to cells near the tissue periphery. Neither GS-I nor UEA exhibited any binding to injured tissue. By 48 h post-injury, the wound area repopulates and endothelial cells begin reestablishing the monolayer. These cells now exhibit increased binding for WGA, especially along regions of cell-to-cell contact, whereas, Con A, RCA and SBA binding patterns remain unchanged. Seventy-two hours after injury, the monolayer is well organized with WGA, Con A and RCA binding patterns becoming similar to those observed for non-injured tissue. However, at this time, SBA binding decreases dramatically. By 1 week post-injury, binding patterns for WGA, ConA and RCA closely resemble their non-injured counterparts while SBA continues to demonstrate low levels of binding. In early stages of its development, the endothelium actively proliferates and morphologically resembles adult tissue during wound repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Endocytosis by the corneal endothelium. I. Regulation of binding and transport of hemeproteins and peroxidase-conjugated lectins across the tissue

“…In part, this occurrence may be explained by the fact that SBA has no sugar binding residues on the endothelial cell surface (Gordon and Marchand 1990). When coupled to HRP, non-specific endocytosis, probably augmented by the presence of the HRP conjugate, results in some vesicles that contain the tracer being circumvented around the tight junctions and then fusing with the lateral membrane.…”

Lectin binding in normal donkey eyeball

“…Heterogeneity in the distribution of the glycoproteins within the Descemet's membrane has been demonstrated previously. 13,28,31 The thin basement membranes showed a marked presence of N-acetylgalactosamine residues, whereas a low concentration of these sugar residues was found in thick basement membranes. 32 Our observations showed binding of Con A and WGA to the corneal endothelium.…”

Distribution of blood-group-related carbohydrate antigens on oral endothelial cells

“…Recent data indicate that BGCA are associated with endothelial cell differentiation (Flemming & Jones, 1989;Gordon & Marchand, 1990), adhesion of inflammatory cells to endothelium (Yednock & Rosen, 1989;Brandley et aI., 1990;Lowe et at., 1990;Osborn, 1990;Siegelman, 1991;Springer & Lasky, 1991), and adhesion of metastatic cells (Auerbach et al, 1987;Rice & Bevilaqua, 1989;Cornil et al, 1990;Springer & Lasky, 1991) to endothelium. Other reports show that endothelial carbohydrates are differentially expressed in various en-0018-2214 9 1993 Chapman & Hall dothelial neoplasms (Feigl et at., 1976;Berry & Amerigo, 1980) and that they play a major role in rejection reactions after organ transplantation (Jordan et al, 1988;Holgersson et al, 1990).…”