Abstract
Abstract: :
Purpose: To examine the distribution of laminin chains in the cornea, lens and retina early in human fetal development. Methods: Eleven eyes were obtained from fetuses at 9-20 weeks of gestation (wg). Serial frozen sections were processed for immunohistochemistry with antibodies (abs) against laminin α1, α2, α3, α4, α5, ß1 and ß2 chains. Results: The cornea was labeled by abs against laminin α1, α3, α4, α5 and ß1 chains. The basement membrane of the corneal epithelium was stained with abs against laminin α3, α5 and ß1 chains through all ages whereas laminin α1 chain was present at 9-11 wg and laminin α4 chain from 10 wg. The Descemet's membrane was labeled with laminin α1 chain ab from 10 wg, with laminin α4 chains and laminin ß1 chains abs at 14-17 wg and with laminin α5 chain ab from 11 wg. The lens capsule was stained with abs against laminin α1, α5, ß1 and ß2 chains at all ages. Laminin α1, α3, α5, ß1and ß2 chains were detected in the basement membranes of the retina. Laminin α1, α5, ß1 and ß2 chains were present in the internal limiting membrane and Bruch's membrane through all ages, whereas laminin α3 chain ab labeled Bruch's membrane from 14 wg. Laminin α4 chain delineated vessels through all ages, even vessels in the corneal stroma at 10-16 wg. The laminin α2 chain ab did not stain any structures in the eye at these stages. Conclusions: Basement membranes play an important role during morphogenesis as they influence cell proliferation, migration and differentiation of tissues. Laminins are the major non-collagenous component of basement membranes. The presence of at least four different alpha chains and two beta chains of laminin with distinct spatial and temporal patterns of distribution in the eye indicate a high degree of complexity and an important role for different laminin chains in human ocular differentiation from the early stages of development. CR:None. Support:KMA
Keywords: extracellular matrix • retinal development • cornea: basic science