Piperaquine-resistant PfCRT mutations differentially impact drug transport, hemoglobin catabolism and parasite physiology in Plasmodium falciparum asexual blood stages

The emergence of multidrug resistance in Plasmodium falciparum parasites presents a significant obstacle to the malaria elimination agenda. Resistance to piperaquine (PPQ), an important first-line partner drug, has spread across Southeast Asia where it has contributed to widespread treatment failures. The genetic cause of resistance to PPQ is attributable to a novel set of amino acid substitutions in the P. falciparum chloroquine resistance transporter (PfCRT). The objective of our study is to characterize gene expression signatures associated with PPQ-resistance associated PfCRT mutations by comparing transcriptional profiles of PPQ-resistant PfCRT mutants (F145I, G353V, M343L) and isogenic PPQ-sensitive lines that were generated by zinc finger nuclease (ZFN) based editing in a long-term adapted (Dd2). We employed microarray technology to establish the global gene expression profiles of these four PfCRT-edited parasite lines (Dd2, Dd2+F145I, Dd2+G353V, Dd2+M343L) and unedited Dd2 at the trophpzoite stage of the intra-erythrocytic developmental cycle. The RNA expression profiles of the PfCRT mutant and isogenic parasites were compared to identify changes at basal levels. Two to three independent experiments were performed for each parasite strain.