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A2E, a component of lipofuscin, is pro‐angiogenic in vivo
Author(s) -
Iriyama Aya,
Inoue Yuji,
Takahashi Hidenori,
Tamaki Yasuhiro,
Jang WooDong,
Yanagi Yasuo
Publication year - 2009
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.21792
Subject(s) - downregulation and upregulation , in vivo , lipofuscin , choroid , microbiology and biotechnology , retinal pigment epithelium , retinal , macular degeneration , vascular endothelial growth factor , retina , cancer research , chemistry , biology , medicine , ophthalmology , neuroscience , biochemistry , vegf receptors , genetics , gene
A recent study in vitro demonstrated that a major lipofuscin component, A2E, serves as a retinoic acid receptor ligand. The current study investigated the effects of A2E on retinal pigment epithelial (RPE) cells in vivo and was performed to extend the understanding of the effects of A2E. Firstly, subretinal injection of A2E was performed and 3 weeks after the injection, and it was demonstrated that subretinal injection of A2E induced RPE cell death, and concomitant upregulation of vascular endothelial growth factor (VEGF) in the RPE and choroid. The upregulation of VEGF was attenuated by an RARα antagonist. Next we performed laser photocoagulation in mice that accumulated A2E either after subretinal injection, by Ccl2 gene knockout or by aging demonstrated that mice that accumulated A2E in the RPE, which showed higher rates of choroidal neobascularization (CNV) formation after weak laser injury than the controls and the formation of CNV was inhibited by an RARα antagonist in all models tested. The data suggest that A2E accumulation induces RPE cell death, and concomitant increase of VEGF. Accumulation of A2E alone is not sufficient to induce CNV in vivo, but induces the expression of VEGF in RPE and choroid. The mice that accumulated A2E in RPE cells are vulnerable to CNV development via RAR activation, at least in part. J. Cell. Physiol. 220: 469–475, 2009. © 2009 Wiley‐Liss, Inc.