title: Molecular response of chorioretinal endothelial cells to complement injury: implications for macular degeneration.
abstract: Age-related macular degeneration (AMD) is a common, blinding disease of the elderly in which macular photoreceptor cells, retinal pigment epithelium and choriocapillaris endothelial cells ultimately degenerate. Recent studies have found that degeneration of the choriocapillaris occurs early in this disease and that endothelial cell drop-out is concomitant with increased deposition of the complement membrane attack complex (MAC) at the choroidal endothelium. However, the impact of MAC injury to choroidal endothelial cells is poorly understood. To model this event in vitro, and to study the downstream consequences of MAC injury, endothelial cells were exposed to complement from human serum, compared to heat-inactivated serum, which lacks complement components. Cells exposed to complement components in human serum showed increased labelling with antibodies directed against the MAC, time- and dose-dependent cell death, as assessed by lactate dehydrogenase assay and increased permeability. RNA-Seq analysis following complement injury revealed increased expression of genes associated with angiogenesis including matrix metalloproteinase (MMP)-3 and -9, and VEGF-A. The MAC-induced increase in MMP9 RNA expression was validated using C5-depleted serum compared to C5-reconstituted serum. Increased levels of MMP9 were also established, using western blot and zymography. These data suggest that, in addition to cell lysis, complement attack on choroidal endothelial cells promotes an angiogenic phenotype in surviving cells.
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Shemin
authors.initials: S
authors.lastname: Zeng
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: S Scott
authors.initials: SS
authors.lastname: Whitmore
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Elliott H
authors.initials: EH
authors.lastname: Sohn
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Riker
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Luke A
authors.initials: LA
authors.lastname: Wiley
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Scheetz
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Budd A
authors.initials: BA
authors.lastname: Tucker
authors.affiliation: Stephen A Wynn Institute for Vision Research and Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Mullins
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000378:metabolism; D016923:Cell Death / Q000502:physiology; D002478:Cells, Cultured; D002829:Choroid / Q000098:blood supply / Q000276:immunology*; D003167:Complement Activation / Q000502:physiology; D015938:Complement Membrane Attack Complex / Q000276:immunology*; D003165:Complement System Proteins / Q000494:pharmacology*; D004306:Dose-Response Relationship, Immunologic; D042783:Endothelial Cells / Q000276:immunology*; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D008297:Male; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D000906:Antibodies; D015938:Complement Membrane Attack Complex; D042461:Vascular Endothelial Growth Factor A; D003165:Complement System Proteins; D019278:Matrix Metalloproteinase 3; D020780:Matrix Metalloproteinase 9
keywords: age-related macular degeneration; complement system; endothelial cells; matrix metalloproteinase