Alteration of PKCζ distribution in the outer retina is associated with cone outer segment and OLM disruption in diabetic rats.

<p>PKCζ staining was located in inner segments (IS) of rod and cones and exclusively in cone OS as evidenced by PKCζ-PNA double labeling in 6-month-old control rats (a). In 6-month-old diabetic rats, no OS staining was detected (a). Furthermore PKCζ staining (red) was lost in S-cones, specifically marked by Blue opsin staining (green), as compared to controls. Some S-cone OS also showed marked structural alterations, suggesting early photoreceptor degeneration (b). In 12-month-old diabetic rats OLM discontinuity (arrows) was evidenced (c). OLM tight-junction disruption was further confirmed on retinal flatmounts by an occludin/PKCζ double staining (d, white arrows).