PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Authors: Kenneth J Mandell; Lennart Berglin; Eric A Severson; Henry F Edelhauser; Charles A Parkos Journal: Invest Ophthalmol Vis Sci Date: 2007-09 Impact factor: 4.799
Authors: R Eldawud; T A Stueckle; S Manivannan; H Elbaz; M Chen; Y Rojanasakul; C Z Dinu Journal: Biosens Bioelectron Date: 2014-03-26 Impact factor: 10.618
Authors: Matina Economopoulou; Jeffrey Hammer; Fei Wang; Robert Fariss; Arvydas Maminishkis; Sheldon S Miller Journal: Invest Ophthalmol Vis Sci Date: 2008-12-05 Impact factor: 4.799