TY - JOUR
T1 - New antimalarial indolone-N-oxides, generating radical species, destabilize the host cell membrane at early stages of Plasmodium falciparum growth
T2 - Role of band 3 tyrosine phosphorylation
AU - Pantaleo, Antonella
AU - Ferru, Emanuela
AU - Vono, Rosa
AU - Giribaldi, Giuliana
AU - Lobina, Omar
AU - Nepveu, Françoise
AU - Ibrahim, Hany
AU - Nallet, Jean Pierre
AU - Carta, Franco
AU - Mannu, Franca
AU - Pippia, Proto
AU - Campanella, Estela
AU - Low, Philip S.
AU - Turrini, Francesco
N1 - Funding Information:
This work was supported by the European Union (Redox Antimalarial Drug Discovery, Read-Up, FP6-2004-LSH-2004-2.3.0-7, Strep No. 018602). We thank Elena Valente and Daniela Ulliers for technical assistance.
PY - 2012/1/15
Y1 - 2012/1/15
N2 - Although indolone-N-oxide (INODs) genereting long-lived radicals possess antiplasmodial activity in the low-nanomolar range, little is known about their mechanism of action. To explore the molecular basis of INOD activity, we screened for changes in INOD-treated malaria-infected erythrocytes (Pf-RBCs) using a proteomics approach. At early parasite maturation stages, treatment with INODs at their IC 50 concentrations induced a marked tyrosine phosphorylation of the erythrocyte membrane protein band 3, whereas no effect was observed in control RBCs. After INOD treatment of Pf-RBCs we also observed: (i) accelerated formation of membrane aggregates containing hyperphosphorylated band 3, Syk kinase, and denatured hemoglobin; (ii) dose-dependent release of microvesicles containing the membrane aggregates; (iii) reduction in band 3 phosphorylation, Pf-RBC vesiculation, and antimalarial effect of INODs upon addition of Syk kinase inhibitors; and (iv) correlation between the IC 50 and the INOD concentrations required to induce band 3 phosphorylation and vesiculation. Together with previous data demonstrating that tyrosine phosphorylation of oxidized band 3 promotes its dissociation from the cytoskeleton, these results suggest that INODs cause a profound destabilization of the Pf-RBC membrane through a mechanism apparently triggered by the activation of a redox signaling pathway rather than direct oxidative damage.
AB - Although indolone-N-oxide (INODs) genereting long-lived radicals possess antiplasmodial activity in the low-nanomolar range, little is known about their mechanism of action. To explore the molecular basis of INOD activity, we screened for changes in INOD-treated malaria-infected erythrocytes (Pf-RBCs) using a proteomics approach. At early parasite maturation stages, treatment with INODs at their IC 50 concentrations induced a marked tyrosine phosphorylation of the erythrocyte membrane protein band 3, whereas no effect was observed in control RBCs. After INOD treatment of Pf-RBCs we also observed: (i) accelerated formation of membrane aggregates containing hyperphosphorylated band 3, Syk kinase, and denatured hemoglobin; (ii) dose-dependent release of microvesicles containing the membrane aggregates; (iii) reduction in band 3 phosphorylation, Pf-RBC vesiculation, and antimalarial effect of INODs upon addition of Syk kinase inhibitors; and (iv) correlation between the IC 50 and the INOD concentrations required to induce band 3 phosphorylation and vesiculation. Together with previous data demonstrating that tyrosine phosphorylation of oxidized band 3 promotes its dissociation from the cytoskeleton, these results suggest that INODs cause a profound destabilization of the Pf-RBC membrane through a mechanism apparently triggered by the activation of a redox signaling pathway rather than direct oxidative damage.
KW - Band 3
KW - Free radicals
KW - Oxidative damage
KW - Plasmodium falciparum
KW - Red blood cells
KW - Tyrosine phosphorylation
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U2 - 10.1016/j.freeradbiomed.2011.11.008
DO - 10.1016/j.freeradbiomed.2011.11.008
M3 - Article
C2 - 22142474
AN - SCOPUS:84855421538
SN - 0891-5849
VL - 52
SP - 527
EP - 536
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 2
ER -