Multiple laminin isoforms in the limbal conjunctiva and episclera

Background Cell adhesion in the limbal region is of outstanding importance for the regeneration of the corneal epithelium and for repair mechanisms after antiglaucomatous fistulating surgery. In the basement membranes cell adhesion is largely modified by the extracellular matrix protein laminin. The aim of our study was to establish the immunohistochemical pattern of the different laminin-isoforms and subunits in the basal membrane of the limbal conjunctiva and episcleral vessels. Material and Method For immunhistochemistry five normal human donor eyes were included; we used antibodies agains the laminin heterotrimers 1 and 2, against the laminin subunits alpha 2, beta 1, beta 2, gamma 2, gamma 2 and against the laminin-associated protein nidogen. Results The basement membrane of the limbal conjunctiva reveals immunoreactivity against all used antibodies. The subconjunctival and episcleral vessels showed no staining for the laminin subunit gamma 2 but for all other used antibodies. Conclusion The basement membrane of the: limbal and conjunctival epithelium as well as the basement membrane of subconjunctival and episcleral vessels express a broad spectrum of laminin variants, This diversity emphasizes functional specialization of the limbal region, although the exact importance of the laminin variants is still unknown.