Abstract
Purpose: The goal of this study was to define the repertoire of integrin expression in the developing mouse retina, particularly vascular expression. Methods: Eyes from 17-21 day old C57BL mice were removed and embedded in OCT and frozen at -70°C. 12 μm sections were prepared and were successively incubated for 1 hour each as follows: PBS with 3%BSA, rat anti-mouse integrin or laminin monoclonal antibody or hamster anti-mouse αv, Texas-Red conjugated secondary antibody or FITC-conjugated for αv, and FITC-conjugated RCA-I lectin. Incubations included appropriate washings with PBS between steps. Double staining with the FITC-conjugated RCA-I lectin was performed for all of the above primary antibodies with the exception of that for αv. Sections were examined by fluorescent microscopy. Results: The expression of laminin in intraretinal vessels was demonstrated by the colocalization of RCA-I, which labels mouse vasculature, and laminin staining.α6 and β1 integrin subunits, which form the laminin receptor α6β1, also localized to intraretinal vessels. α6 staining was also seen in cells of the inner nuclear cell layer. The retinal vasculature had minimal β4 staining and lacked α2, α3, α5, and αv staining. α3 staining was seen in the outer synaptic layer.Conclusion: Intraretinal vessels in the developing mouse retina express laminin and the integrin laminin receptorsα6β1 and minimally α6β4. No vascular staining for the integrin subunits α2, α3,α5, or αv were demonstrated.