Annexins in Retina-choroid Complex: Gene Expression and Protein Distribution

Abstract

Abstract: : Purpose: The annexins constitute a family of calcium-dependent phospholipid-binding proteins. Several annexins have been identified in our proteomic studies of drusen. To localize the distribution of annexins I-VI in the retina-choroid complex of human eyes, we pursued Western and immunocytochemical analyses using a series of anti-annexin antibodies and also conducted RT-PCR. Methods: The ocular tissues analyzed were retina, retinal pigment epithelium, and Bruch’s membrane / choroid. RT-PCR and western blots were performed for the demonstration of annexins. Tissues from human eyes embedded in paraffin were used for immunohistochemistry. Commercially available annexin antibodies were used for light microscopy employing the ABC method. Results: All annexins studied except annexin-III, were localized using immunocytochemistry throughout the retina, in the RPE, Bruch’s membrane / choroid. Annexins I and II were expressed more strongly in Bruch’s membrane and choroid than in the retina and RPE. Annexins IV, V and VI were expressed more strongly in retina than in the RPE, Bruch’s membrane and choroid. Conclusions: All the annexins we studied except annexin III are present in RPE, choroid and retina. Although annexin function is still not clearly defined, detected annexins exhibit a characteristic expression pattern in the retina-choroid complex. Supported by NIH-NEI and FFB. None

Keywords: gene/expression • immunohistochemistry • retina