title: The role of complement in age-related macular degeneration: heparan sulphate, a ZIP code for complement factor H?
abstract: Age-related macular degeneration (AMD) is the leading cause of blindness in developed nations and has been associated with complement dysregulation in the central retina. The Y402H polymorphism in the complement regulatory protein factor H (CFH) can confer a >5-fold increased risk of developing AMD and is present in approximately 30% of people of European descent. CFH, in conjunction with other factors, regulates complement activation in host tissues, and the Y402H polymorphism has been found to alter the protein's specificity for heparan sulphate (HS) - a complex polysaccharide found ubiquitously in mammals. HS, which is present on the cell surface and also in the extracellular matrix, exhibits huge structural diversity due to variations in the level/pattern of sulphation, where particular structures may act as 'ZIP codes' for different tissue/cellular locations. Recent work has demonstrated that CFH contains two HS-binding domains that each recognize specific HS ZIP codes, allowing differential recognition of Bruch's membrane (in the eye) or the glomerular basement membrane (in the kidney). Importantly, the Y402H polymorphism impairs the binding of CFH to the HS in Bruch's membrane, which could result in increased complement activation and chronic local inflammation (in 402H individuals) and thereby contribute to AMD pathology.
authors: Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK.
authors: Alex
authors: A
authors: Langford-Smith
authors: Tiarnan D L
authors: TD
authors: Keenan
authors: Simon J
authors: SJ
authors: Clark
authors: Paul N
authors: PN
authors: Bishop
authors: Anthony J
authors: AJ
authors: Day
mesh_terms: D000818:Animals; D016570:Bruch Membrane / Q000378:metabolism*; D003167:Complement Activation / Q000235:genetics; D017242:Complement Factor H / Q000235:genetics / Q000276:immunology*; D020022:Genetic Predisposition to Disease; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D008268:Macular Degeneration / Q000276:immunology*; D011110:Polymorphism, Genetic; D011485:Protein Binding / Q000235:genetics; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D012160:Retina / Q000276:immunology* / Q000473:pathology
chemical_list: D017242:Complement Factor H; D006497:Heparan Sulfate