Antibody Blockade of Junctional Adhesion Molecule-A in Rabbit Corneal Endothelial Tight Junctions Produces Corneal Swelling

• Published in: Investigative ophthalmology & visual science Vol. 47; no. 6; pp. 2408 - 2416
• Main Authors: Mandell, Kenneth J, Holley, Glenn P, Parkos, Charles A, Edelhauser, Henry F
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.06.2006; Association for Research in Vision and Ophtalmology
• Subjects: Animals; Antibodies, Blocking - physiology; Antibodies, Monoclonal; Biological and medical sciences; Blotting, Western; Cell Adhesion Molecules - physiology; Cell Membrane Permeability; Corneal Edema - metabolism; Diseases of cornea, anterior segment and sclera; Endothelium, Corneal - metabolism; Eye and associated structures. Visual pathways and centers. Vision; Female; Fluorescent Antibody Technique, Indirect; Fundamental and applied biological sciences. Psychology; Immunoglobulins - physiology; Kinesin - metabolism; Medical sciences; Membrane Proteins - metabolism; Mice; Mice, Inbred BALB C; Microscopy, Confocal; Myosins - metabolism; Ophthalmology; Phosphoproteins - metabolism; Rabbits; Receptors, Cell Surface; Tight Junctions - metabolism; Vertebrates: nervous system and sense organs; Zonula Occludens-1 Protein; Corneal edema; Cornea; Antibody; Rabbit; Keratopathy; Lagomorpha; Adhesion; Eye disease; Vertebrata; Mammalia; Animal; Tight junction; Ophthalmology; Anterior segment disease
• ISSN: 0146-0404; 1552-5783; 1552-5783
• DOI: 10.1167/iovs.05-0745

The ultrastructure of tight junctions in the corneal endothelium has been studied extensively, yet little is known about their molecular composition. Junctional adhesion molecule-A (JAM-A) is a tight junction-associated adhesion protein previously implicated in tight junction assembly and regulation of barrier function. In this study, we sought to investigate the expression and function of JAM-A in the corneal endothelium. Immunofluorescence confocal microscopy was used to investigate expression of JAM-A and the related proteins JAM-C, CAR, and AF-6 in the rabbit corneal endothelium. Corneal endothelial perfusion specular microscopy was then used to test the effects of antibodies to JAM-A on corneal swelling. The expression of JAM-A was observed in the tight junctions of rabbit corneal endothelium in a localization pattern identical with that of ZO-1, a known marker of the tight junction and binding partner of JAM-A. Expression of related proteins JAM-C and CAR (Coxsackie and adenovirus receptor) was also observed in the corneal endothelium, but their distribution was diffuse and not limited to the tight junction. Expression of AF-6, a known binding partner of JAM-A, was also observed in the tight junction in a pattern similar to ZO-1. Last, functional experiments were performed in which a monoclonal antibody to JAM-A was shown to increase rabbit corneal swelling by 63% compared with the control. The results provide new evidence that JAM-A and its binding partner AF-6 are expressed in tight junctions of the corneal endothelium and that JAM-A has a major role in maintaining the corneal endothelial barrier function.