title: CFH Y402H polymorphism and the complement activation product C5a: effects on NF-κB activation and inflammasome gene regulation.
abstract: OBJECTIVE
  The Y402H polymorphism in the complement factor H (CFH) gene is an important risk factor for age-related macular degeneration (AMD). Complement activation products and proinflammatory cytokines are associated with this polymorphism at the systemic level, but less is known of the associations in the outer retina of the genotyped eye. Here we investigate complement activation products and their role in nuclear factor (NF)-κB activation and gene expression of the NLRP3 inflammasome pathway.
  
  
  METHODS
  Postmortem donor eyes were genotyped for the CFH Y402H polymorphism and assessed for complement C3a, C5a, interleukin (IL)-18 and tumour necrosis factor (TNF)-α. ARPE19 cells were stimulated basolaterally with C5a or TNF-α in polarised cultures. NF-κB activation was assessed with a reporter cell line. Gene expression of inflammasome-related (NLRP3, caspase-1, IL-1β and IL-18) and classic inflammatory (IL-6 and IL-8) genes was studied. The distribution of inflammasome products, IL-1β and IL-18, was studied in postmortem donor eyes with AMD pathologies.
  
  
  RESULTS
  Eyes with the homozygous at-risk variant demonstrated higher levels of C5a, IL-18 and TNF-α in Bruch's membrane and choroid. C5a promoted NF-κB activation and upregulation of IL-18 in polarised ARPE19. TNF-α promoted NF-κB activation and gene expression of caspase-1, IL-1β, IL-18, IL-6 and IL-8, but downregulated NLRP3. In eyes with geographic atrophy, strong immunoreactivity was observed for inflammasome products IL-1β and IL-18 compared with age-matched controls.
  
  
  CONCLUSIONS
  The at-risk polymorphism of the CFH Y402H may contribute to AMD disease process through increased complement and NF-κB activation, and the upregulation of IL-18, a product of inflammasome activation.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Sijia
authors.initials: S
authors.lastname: Cao
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jay Ching Chieh
authors.initials: JC
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jiangyuan
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Wong
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Elliott
authors.initials: E
authors.lastname: To
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Valerie A
authors.initials: VA
authors.lastname: White
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jing Z
authors.initials: JZ
authors.lastname: Cui
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Joanne A
authors.initials: JA
authors.lastname: Matsubara
mesh_terms: D002352:Carrier Proteins / Q000235:genetics; D002460:Cell Line; D003167:Complement Activation; D015936:Complement C5a / Q000494:pharmacology*; D017242:Complement Factor H / Q000235:genetics; D016207:Cytokines / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D060005:Genotyping Techniques; D006801:Humans; D007150:Immunohistochemistry; D058847:Inflammasomes / Q000235:genetics*; D016328:NF-kappa B / Q000378:metabolism*; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D055213:Retinal Pigment Epithelium / Q000187:drug effects* / Q000378:metabolism; D014019:Tissue Donors
chemical_list: C493495:CFH protein, human; D002352:Carrier Proteins; D016207:Cytokines; D058847:Inflammasomes; D016328:NF-kappa B; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human; D015936:Complement C5a; D017242:Complement Factor H
keywords: Pathology; Retina