Hydroxyurea-induced oxidative damage of normal and sickle cell hemoglobins in vitro: Amelioration by radical scavengers

Iyamu, Efe W.; Fasold, H.; Roa, D; Aguinaga, Maria del Pilar; Asakura, Toshio; Turner, Edward L.

doi:10.1002/1098-2825(2001)15:1<1::aid-jcla1>3.0.co;2-i

Cited by 18 publications

(17 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An increase in these enzymes suggests an adaptive response of the RBCs to oxidative damage. These findings are in agreement with the findings of Iyamu et al (13) that HU-induced oxidative damage of Hb can be ameliorated by radical scavengers. Similarly, Eskenazi et al (14) demonstrated that resistance to exogenous H 2 O 2 after HU treatment in B16 melanoma cells was accompanied by an increase in free radical scavengers like glutathione reductase, glutathione peroxidase and catalase activities.…”

Section: Discussionsupporting

confidence: 93%

Pharmaco-Proteomic Study of Hydroxyurea-Induced Modifications in the Sickle Red Blood Cell Membrane Proteome

Ghatpande

Choudhary

Quinn

et al. 2008

Exp Biol Med (Maywood)

View full text Add to dashboard Cite

Hydroxyurea (HU) is an effective oral drug for the management of homozygous sickle cell anemia (SS) in part because it increases fetal hemoglobin (HbF) levels within sickle red blood cells (RBCs) and thus reduces sickling. However, results from the Multicenter Study of HU suggested that clinical symptoms often improved before a significant increase in HbF levels occurred. This indicated that HU may be acting through the modification of additional cellular mechanisms that are yet to be identified. Hence, in this study, we focused on the analysis of the sickle RBC membrane proteome +/− HU treatment. 2D-DIGE (Two Dimensional Difference In-Gel Electrophoresis) technology and tandem mass spectrometry has been used to determine quantitative differences between sickle cell membrane proteins in the presence and absence of a clinically relevant concentration of HU. In vitro protein profiling of 13 sickle RBC membrane samples +/− 50 μM HU identified 10 statistically significant protein spots. Of these, the most remarkable class of proteins to show a statistically significant increase was the antioxidant enzymes—catalase, thioredoxin peroxidase and biliverdin reductase and the chaperonin containing TCP1 complex assisting in the folding of RBC cytoskeletal proteins. Interestingly, catalase immunoblots showed an increase in the acidic forms of the enzyme within sickle RBC membranes on incubation with 50 μM HU. We further identified this modification in catalase to be phosphorylation and demonstrated that HU exposed SS RBC membranes showed a 2-fold increase in tyrosine phosphorylation of catalase as compared to counterparts not exposed to HU. These results present an attractive model for HU-induced post-translational modification and potential activation of catalase in mature sickle RBCs. These findings also identify protein targets of HU other than fetal hemoglobin and enhance the understanding of the drug mechanism.

show abstract

Section: Discussionsupporting

confidence: 93%

Pharmaco-Proteomic Study of Hydroxyurea-Induced Modifications in the Sickle Red Blood Cell Membrane Proteome

Ghatpande

Choudhary

Quinn

et al. 2008

Exp Biol Med (Maywood)

View full text Add to dashboard Cite

show abstract

“…Further investigation to assess the post-translational modification of catalase using 2D quantitative western blotting showed a twofold increase in tyrosine phosphorylation with hydroxyurea exposure. This observation is consistent with prior studies that showed phosphorylation of catalase by tyrosine kinases in response to oxidative stress, increasing catalase activity at a post-translational level [46–48]. It is remarkable that this set of in vitro hydroxyurea experiments yielded alterations in protein abundance, since the principal effects of hydroxyurea have previously been attributed to alterations in transcriptional regulation that are not possible in enucleated mature RBCs.…”

Section: Rbc Membrane Proteomics In Scdsupporting

confidence: 91%

The proteome of sickle cell disease: insights from exploratory proteomic profiling

Yuditskaya¹,

Suffredini²,

Kato³

2010

Expert Review of Proteomics

View full text Add to dashboard Cite

The expanding realm of exploratory proteomics has added a unique dimension to the study of the complex pathophysiology involved in sickle cell disease. A review of proteomic studies published on sickle cell erythrocytes and plasma shows trends of upregulation of antioxidant proteins, an increase in cytoskeletal defects, an increase in protein repair and turnover components, a decrease in lipid raft proteins and apolipoprotein dysregulation. Many of these findings are consistent with the pathophysiology of sickle cell disease, including high oxidant burden, resulting in damage to cytoskeletal and other proteins, and erythrocyte rigidity. More unexpected findings, such as a decrease in lipid raft components and apolipoprotein dysregulation, offer previously unexplored targets for future investigation and potential therapeutic intervention. Exploratory proteomic profiling is a valuable source of hypothesis generation for the cellular and molecular pathophysiology of sickle cell disease.

show abstract

“…Hydroxyurea also induces both hemoglobin denaturation and oxidative damage within red blood cells [97][98][99][100]. Further EPR examination of the reaction of oxyhemoglobin and hydroxyurea reveals the formation of three other paramagnetic species in addition to methemoglobin [101].…”

Section: Reactions With Heme Proteinsmentioning

confidence: 97%

The Nitric Oxide Producing Reactions of Hydroxyurea

King¹

2003

CMC

View full text Add to dashboard Cite

Hydroxyurea is used to treat a variety of cancers and sickle cell disease. Despite this widespread use, a complete mechanistic understanding of the beneficial actions of this compound remains to be understood. Hydroxyurea inhibits ribonucleotide reductase and increases the levels of fetal hemoglobin, which explains a portion of the effects of this drug. Administration of hydroxyurea to patients results in a significant increase in levels of iron nitrosyl hemoglobin, nitrite and nitrate suggesting the in vivo metabolism of hydroxyurea to nitric oxide. Formation of nitric oxide from hydroxyurea may explain a portion of the observed effects of hydroxyurea treatment. At the present, the mechanism or mechanisms of nitric oxide release, the identity of the in vivo oxidant and the site of metabolism remain to be identified. Chemical oxidation of hydroxyurea produces nitric oxide and nitroxyl, the one-electron reduced form of nitric oxide. These oxidative pathways generally proceed through the nitroxide radical (2) or C-nitrosoformamide (3). Biological oxidants, including both iron and copper containing enzymes and proteins, also convert hydroxyurea to nitric oxide or its decomposition products in vitro and these reactions also occur through these intermediates. A number of other reactions of hydroxyurea including the reaction with ribonucleotide reductase and irradiation demonstrate the potential to release nitric oxide and should be further investigated. Gaining an understanding of the metabolism of hydroxyurea to nitric oxide will provide valuable information towards the treatment of these disorders and may lead to the development of better therapeutic agents.

show abstract

Hydroxyurea-induced oxidative damage of normal and sickle cell hemoglobins in vitro: Amelioration by radical scavengers

Cited by 18 publications

References 20 publications

Pharmaco-Proteomic Study of Hydroxyurea-Induced Modifications in the Sickle Red Blood Cell Membrane Proteome

Pharmaco-Proteomic Study of Hydroxyurea-Induced Modifications in the Sickle Red Blood Cell Membrane Proteome

The proteome of sickle cell disease: insights from exploratory proteomic profiling

The Nitric Oxide Producing Reactions of Hydroxyurea

Contact Info

Product

Resources

About