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This Article Full Text Full Text (PDF) Supplemental Figures All Versions of this Article: 297/2/C378    most recent 00543.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Mihov, D. Articles by Bogdanova, A. PubMed PubMed Citation Articles by Mihov, D. Articles by Bogdanova, A.

RECEPTORS AND SIGNAL TRANSDUCTION

Erythropoietin activates nitric oxide synthase in murine erythrocytes

Institute of Veterinary Physiology, Vetsuisse Faculty and Zürich Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland

Submitted 22 October 2008 ; accepted in final form 9 June 2009

Erythropoietin (Epo) is the main regulator of erythrocyte production and a potent cytoprotective factor. It was suggested that some of Epo cytoprotective properties are due to its regulation of nitric oxide (NO) production. Recently, functionally active endothelial type NO synthase (eNOS) was discovered in mature murine and human red blood cells (RBC-eNOS). The goal of the present study was to characterize the effect of physiological and therapeutic doses of Epo on RBC-eNOS function. We found that recombinant human Epo (rHuEpo) binds specifically to mouse erythrocytes. Epo binding sites are not equally distributed through the RBC population but prevail in reticulocytes and young erythrocytes with about 105 receptors/cell, compared with adult and old erythrocytes containing 1–4 receptors/cell. The treatment of mouse erythrocytes with rHuEpo resulted in a time- and dose-dependent upregulation of NO production mediated via activation of the phosphatidylinositol-3-kinase /Akt pathway and RBC-eNOS phosphorylation at Ser-1177. Finally, when erythrocytes were incubated in L-arginine-free medium, rHuEpo treatment resulted in upregulation of superoxide radical production with concomitant shifting of the cellular redox state toward more oxidized state. Epo-induced changes in erythrocyte redox potential were absent in erythrocytes from eNOS-deficient mice.

red blood cells; phosphatidylinositol-3-kinase/Akt pathway; nitric oxide production; redox state