Erythropoietin and a nonerythropoietic peptide analog promote aortic endothelial cell repair under hypoxic conditions: role of nitric oxide

Heikal, Lamia, Ghezzi, Pietro, Mengozzi, Manuela, Stelmaszczuk, Blanka, Feelisch, Martin and Ferns, Gordon A A (2016) Erythropoietin and a nonerythropoietic peptide analog promote aortic endothelial cell repair under hypoxic conditions: role of nitric oxide. Hypoxia, 4. pp. 121-133. ISSN 2324-1128

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Abstract

The cytoprotective effects of erythropoietin (EPO) and an EPO-related nonerythropoietic analog, pyroglutamate helix B surface peptide (pHBSP), were investigated in an in vitro model of bovine aortic endothelial cell injury under normoxic (21% O2) and hypoxic (1% O2) conditions. The potential molecular mechanisms of these effects were also explored. Using a model of endothelial injury (the scratch assay), we found that, under hypoxic conditions, EPO and pHBSP enhanced scratch closure by promoting cell migration and proliferation, but did not show any effect under normoxic conditions. Furthermore, EPO protected bovine aortic endothelial cells from staurosporine-induced apoptosis under hypoxic conditions. The priming effect of hypoxia was associated with stabilization of hypoxia inducible factor-1α, EPO receptor upregulation, and decreased Ser-1177 phosphorylation of endothelial nitric oxide synthase (NOS); the effect of hypoxia on the latter was rescued by EPO. Hypoxia was associated with a reduction in nitric oxide (NO) production as assessed by its oxidation products, nitrite and nitrate, consistent with the oxygen requirement for endogenous production of NO by endothelial NOS. However, while EPO did not affect NO formation in normoxia, it markedly increased NO production, in a manner sensitive to NOS inhibition, under hypoxic conditions. These data are consistent with the notion that the tissue-protective actions of EPO-related cytokines in pathophysiological settings associated with poor oxygenation are mediated by NO. These findings may be particularly relevant to atherogenesis and postangioplasty restenosis.

Item Type: Article
Keywords: Erythropoietin, Pyroglutamate helix B surface peptide, Scratch assay, Proliferation, Migration, Apoptosis
Schools and Departments: Brighton and Sussex Medical School > Clinical and Experimental Medicine
Brighton and Sussex Medical School > Division of Medical Education
Subjects: R Medicine
R Medicine > RM Therapeutics. Pharmacology
R Medicine > RM Therapeutics. Pharmacology > RM0300 Drugs and their actions
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Depositing User: Lamia Heikal
Date Deposited: 06 Sep 2016 09:12
Last Modified: 25 Sep 2017 09:18
URI: http://sro.sussex.ac.uk/id/eprint/63153

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