Premium
Stimulation of GATA‐2 as a mechanism of hydrogen peroxide suppression in hypoxia‐induced erythropoietin gene expression
Author(s) -
Tabata Masahiko,
Tarumoto Takahisa,
Ohmine Ken,
Furukawa Yusuke,
Hatake Kiyohiko,
Ozawa Keiya,
Hasegawa Yuichi,
Mukai Harumi,
Yamamoto Masayuki,
Imagawa Shigehiko
Publication year - 2001
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 - 10.1002/1097-4652(200002)186:2<260::aid-jcp1025>3.0.co;2-k
Subject(s) - microbiology and biotechnology , transfection , erythropoietin , reporter gene , electrophoretic mobility shift assay , catalase , gene expression , promoter , gene , chemistry , biology , biochemistry , enzyme , endocrinology
Hydrogen peroxide (H 2 O 2 ) has previously been shown to inhibit the DNA binding activity of hypoxia inducible factor‐1 (HIF‐1), the accumulation of HIF‐1α protein and erythropoietin (Epo) gene expression. Epo gene expression has been previously shown to be down‐regulated through a GATA binding site at its promoter region. In this study, the effect of H 2 O 2 on Epo gene expression under hypoxic conditions through a GATA transcription factor was investigated. Hypoxic induction was found to be inhibited upon the addition of H 2 O 2 , and this effect could be reversed through the addition of catalase. Hypoxic induction was found to be suppressed by co‐transfection with a human GATA‐2 cDNA expression plasmid. Transfection of Hep3B cells with a reporter gene bearing a mutation at the promoter GATA binding site was found to be only mildly affected by the addition of H 2 O 2 . Electrophoretic gel mobility shift assays (EMSAs), using the Epo promoter GATA site as a probe and the GATA‐2 protein extracted from Hep3B cells, showed that addition of H 2 O 2 enhanced the binding of GATA‐2 while addition of catalase inhibited this binding. From these results, we conclude that H 2 O 2 increases the binding activity of GATA‐2 in a specific manner, thereby suppressing the activity of the Epo promoter and thus inhibiting Epo gene expression. J. Cell. Physiol. 186:260–267, 2001. © 2001 Wiley‐Liss, Inc.