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Hypoxia up‐regulates hemoglobin expression in cultured human retinal pigment epithelium (RPE)
Author(s) -
Mangini Nancy J,
Fetea Teodora,
Schaab Tara,
Kennedy Brian G.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.717.1
Subject(s) - hemoglobin , immunocytochemistry , retina , retinal pigment epithelium , hypoxia (environmental) , retinal , biology , microbiology and biotechnology , oxygenation , chemistry , anatomy , biochemistry , oxygen , endocrinology , neuroscience , ecology , organic chemistry
RPE is a transporting epithelial monolayer situated between sensory retina and its choroidal blood supply. The retina is among the most metabolically active tissues, with photoreceptors exhibiting the highest O 2 demand. 100% of O 2 delivered to photoreceptors comes across the RPE; even small decrements in oxygenation lead to measurable changes in vision. Recent studies suggest hemoglobin in RPE facilitates O 2 delivery. The present study examined the effect of hypoxia on hemoglobin expression in RPE. Proteomic analysis revealed the presence of hemoglobin chains in cultured human RPE and demonstrated up‐regulation in response to a treatment that altered pH. Hemoglobin antibodies were used for western blotting and immunocytochemistry to compare RPE hemoglobin expression under control‐and hypoxic conditions. Our studies demonstrated the presence of hemoglobin alpha ‐, beta ‐and delta chains in RPE. Immunocytochemistry revealed increased staining and a marked subcellular redistribution in response to hypoxic conditions. The effect was most pronounced for hemoglobin delta . Hemoglobin is expressed in cultured RPE and expression is sensitive to oxygen levels. Supported by IUSM‐NW Research Funds