Hydroxyurea induces fetal hemoglobin by the nitric oxide–dependent activation of soluble guanylyl cyclase
Vladan P. Cokic, … , Mark T. Gladwin, Alan N. Schechter
Vladan P. Cokic, … , Mark T. Gladwin, Alan N. Schechter
Published January 15, 2003
Citation Information: J Clin Invest. 2003;111(2):231-239. https://doi.org/10.1172/JCI16672.
View: Text | PDF
Article Aging

Hydroxyurea induces fetal hemoglobin by the nitric oxide–dependent activation of soluble guanylyl cyclase

Abstract

Hydroxyurea treatment of patients with sickle-cell disease increases fetal hemoglobin (HbF), which reduces hemoglobin S polymerization and clinical complications. Despite its use in the treatment of myeloproliferative diseases for over 30 years, its mechanism of action remains uncertain. Recent studies have demonstrated that hydroxyurea generates the nitric oxide (NO) radical in vivo, and we therefore hypothesized that NO-donor properties might determine the hemoglobin phenotype. We treated both K562 erythroleukemic cells and human erythroid progenitor cells with S-nitrosocysteine (CysNO), an NO donor, and found similar dose- and time-dependent induction of γ-globin mRNA and HbF protein as we observed with hydroxyurea. Both hydroxyurea and CysNO increased cGMP levels, and the guanylyl cyclase inhibitors ODQ, NS 2028, and LY 83,538 abolished both the hydroxyurea- and CysNO-induced γ-globin expression. These data provide strong evidence for an NO-derived mechanism for HbF induction by hydroxyurea and suggest possibilities for therapies based on NO-releasing or -potentiating agents.

Authors

Vladan P. Cokic, Reginald D. Smith, Bojana B. Beleslin-Cokic, Joyce M. Njoroge, Jeffery L. Miller, Mark T. Gladwin, Alan N. Schechter

×

Figure 5

Options: View larger image (or click on image) Download as PowerPoint
HPLC analysis of changes in HbF during maturation of erythroid cells. On...
HPLC analysis of changes in HbF during maturation of erythroid cells. On day 4 of erythroid cell culture, we treated erythroid progenitor cells either with hydroxyurea (white bars) or CysNO (gray bars) and measured HbF versus total hemoglobin levels at different time points during erythroid maturation. (a) Chromatograms of HPLC analyses of hemoglobins produced by erythroid precursor cells during treatment with hydroxyurea (30 μM, red line) and CysNO (100 μM, blue line) on day 10. (b and c) Increases in the percent of HbF to total hemoglobin after treatment with 30 μM hydroxyurea (b) and 100 μM CysNO (c). Values represent means ± SEM (n = 4). *P < 0.05 and **P < 0.01 versus control.