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Expression and function of iron‐regulatory proteins in retina
Author(s) -
GnanaPrakasam Jaya P.,
Martin Pamela M.,
Smith Sylvia B.,
Ganapathy Vadivel
Publication year - 2010
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1002/iub.326
Subject(s) - ferroportin , hepcidin , biology , retina , transferrin receptor , hemochromatosis , microbiology and biotechnology , retinal pigment epithelium , retinal degeneration , homeostasis , transferrin , immunology , endocrinology , genetics , neuroscience , inflammation
Iron is essential for cell survival and function; yet excess iron is toxic to cells. Therefore, the cellular and whole‐body levels of iron are regulated exquisitely. At least a dozen proteins participate in the regulation of iron homeostasis. Hemochromatosis, a genetic disorder of iron overload, is caused by mutations in at least five genes, namely HFE, hemojuvelin, Transferrin receptor 2, ferroportin , and hepcidin . Retina is separated from systemic circulation by inner and outer blood‐retinal barriers; therefore it is widely believed that this tissue is immune to changes in systemic circulation. Even though hemochromatosis is associated with iron overload and dysfunction of a variety of systemic organs, little is known on the effects of this disease on the retina. Recent studies have shown that all five genes that are associated with hemochromatosis are expressed in the retina in a cell type‐specific manner. The retinal pigment epithelium, which forms the outer blood‐retinal barrier, expresses all of these five genes. It is therefore clearly evident that iron homeostasis in the retina is maintained locally by active participation of various iron‐regulatory proteins. Excess iron is detrimental to the retina as evidenced from human studies and from mouse models of iron overload. Retinal iron homeostasis is disrupted in various clinical conditions such as hemochromatosis, aceruloplasminemia, age‐related macular degeneration, and bacterial and viral infections. © 2010 IUBMB IUBMB Life, 62(5): 363–370, 2010