Detection of integrins in human cataract lens epithelial cells and two mammalian lens epithelial cell lines.

AIM: To compare the incidence of various integrin subunits in human cataract anterior lens epithelial cells (A-LEC) and in two mammalian LEC lines. METHODS: Circular sections of anterior capsules with attached LEC were obtained during cataract surgery. Integrin subunits were immunolocalised in these anterior LEC and in a human and rabbit LEC line, using four monoclonal antibodies specific for subunits alpha2, alpha3, and alpha5, and beta subunit 2. RESULTS: All of these subunits were found in at least a proportion A-LEC samples as follows: alpha2 71%, alpha3 92%, alpha5 62%, and beta2 24%. The human LEC line was immunoreactive for alpha2 and alpha3 only. The rabbit lens epithelial cell line was immunoreactive for alpha5 but there was no staining for alpha2, alpha3, or beta2. CONCLUSION: The A-LEC and mammalian LEC lines showed a similarity in their pattern of integrin expression. As these integrins are receptors for extracellular matrix (ECM) components, they are likely to be associated with the attachment and migration of LECs that precedes capsular opacification. Therefore these cell lines may be useful in the elucidation of mechanisms involved the pathogenesis of capsule opacification.

Expression of CD18, CD49b, CD49c and CD49e on lens anterior capsules in human cataracts.

PURPOSE: To examine the lens epithelial cells obtained from the anterior lens capsules removed during cataract surgery and detect various subclasses of the cell surface adhesion molecules known as integrins. METHODS: The circular sections of anterior capsules with attached lens epithelial cells (LECs) were obtained during cataract surgery from 28 patients. The lens capsules were immunohistochemically stained. RESULTS: CD49b CD49c, CD49e, and CD18 were detected in varying degrees in specimens obtained from human cataractous lenses. The positive percentages were 33, 75, 33, and 20%, respectively. The most striking feature was the increasing staining profiles towards the edges of the capsules (away from the central part of the lens capsules) for CD49c, suggesting that the LECs showed higher immunoreactivity for this antibody. The immunoreactivity for CD49b and CD49e was weaker. This was absent for CD18 in the central part of the lens capsules. CONCLUSION: The positive expression of antibodies suggests that specific integrin subunits were expressed in LECs of human cataracts. These results suggest that lens epithelial cells expressing CD49b, CD49c, CD49e, and CD18 might be precursors in the process of anterior lens epithelial cell (A cell) adhesion, and hence play a role in anterior capsule opacification or in subsequent migration and a possible role in posterior capsule opacification.