The Lipid Moiety of Haemozoin (Malaria Pigment) and P. falciparum Parasitised Red Blood Cells Bind Synthetic and Native Endothelin-1

• Main Authors: Nicoletta Basilico, Silvia Parapini, Francesca Sisto, Fausta Omodeo-Salè, Paolo Coghi, Fernando Ravagnani, Piero Olliaro, Donatella Taramelli
• Format: Article
• Language: English
• Published: Hindawi Limited 2010-01-01
• Series: Journal of Biomedicine and Biotechnology
• Online Access: http://dx.doi.org/10.1155/2010/854927

Endothelin1 (ET-1) is a 21-amino acid peptide produced by the vascular endothelium under hypoxia, that acts locally as regulator of vascular tone and inflammation. The role of ET-1 in Plasmodium falciparum malaria is unknown, although tissue hypoxia is frequent as a result of the cytoadherence of parasitized red blood cell (pRBC) to the microvasculature. Here, we show that both synthetic and endothelial-derived ET-1 are removed by parasitized RBC (D10 and W2 strains, chloroquine sensitive, and resistant, resp.) and native haemozoin (HZ, malaria pigment), but not by normal RBC, delipidized HZ, or synthetic beta-haematin (BH). The effect is dose dependent, selective for ET-1, but not for its precursor, big ET-1, and not due to the proteolysis of ET-1. The results indicate that ET-1 binds to the lipids moiety of HZ and membranes of infected RBCs. These findings may help understanding the consequences of parasite sequestration in severe malaria.