Dataset Information

A 4-cyano-3-methylisoquinoline inhibitor of Plasmodium falciparum growth targets the sodium efflux pump PfATP4.

ABSTRACT: We developed a novel series of antimalarial compounds based on a 4-cyano-3-methylisoquinoline. Our lead compound MB14 achieved modest inhibition of the growth in vitro of the human malaria parasite, Plasmodium falciparum. To identify its biological target we selected for parasites resistant to MB14. Genome sequencing revealed that all resistant parasites bore a single point S374R mutation in the sodium (Na+) efflux transporter PfATP4. There are many compounds known to inhibit PfATP4 and some are under preclinical development. MB14 was shown to inhibit Na+ dependent ATPase activity in parasite membranes, consistent with the compound targeting PfATP4 directly. PfATP4 inhibitors cause swelling and lysis of infected erythrocytes, attributed to the accumulation of Na+ inside the intracellular parasites and the resultant parasite swelling. We show here that inhibitor-induced lysis of infected erythrocytes is dependent upon the parasite protein RhopH2, a component of the new permeability pathways that are induced by the parasite in the erythrocyte membrane. These pathways mediate the influx of Na+ into the infected erythrocyte and their suppression via RhopH2 knockdown limits the accumulation of Na+ within the parasite hence protecting the infected erythrocyte from lysis. This study reveals a role for the parasite-induced new permeability pathways in the mechanism of action of PfATP4 inhibitors.

SUBMITTER: Gilson PR

PROVIDER: S-EPMC6635429 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A 4-cyano-3-methylisoquinoline inhibitor of Plasmodium falciparum growth targets the sodium efflux pump PfATP4.

Gilson Paul R PR Kumarasingha Rasika R Thompson Jennifer J Zhang Xinxin X Penington Jocelyn Sietsma JS Kalhor Robabeh R Bullen Hayley E HE Lehane Adele M AM Dans Madeline G MG de Koning-Ward Tania F TF Holien Jessica K JK Soares da Costa Tatiana P TP Hulett Mark D MD Buskes Melissa J MJ Crabb Brendan S BS Kirk Kiaran K Papenfuss Anthony T AT Cowman Alan F AF Abbott Belinda M BM

Scientific reports 20190716 1

We developed a novel series of antimalarial compounds based on a 4-cyano-3-methylisoquinoline. Our lead compound MB14 achieved modest inhibition of the growth in vitro of the human malaria parasite, Plasmodium falciparum. To identify its biological target we selected for parasites resistant to MB14. Genome sequencing revealed that all resistant parasites bore a single point S374R mutation in the sodium (Na<sup>+</sup>) efflux transporter PfATP4. There are many compounds known to inhibit PfATP4 a ...[more]

PMID: 31311978

Similar Datasets

Project description:There is great concern regarding the rapid emergence and spread of drug-resistance in Plasmodium falciparum, the parasite responsible for the most severe form of human malaria. Parasite populations resistant to some or all the currently available antimalarial treatments are present in different world regions. Considering the need for novel and integrated approaches to control malaria, combinations of drugs were tested on P. falciparum. The primary focus was on doxycycline, an antibiotic that specifically targets the apicoplast of the parasite. In combination with doxycycline, three different drugs known to inhibit efflux pumps (verapamil, elacridar and ivermectin) were tested, with the assumption that they could increase the intracellular concentration of the antibiotic and consequently its efficacy against P. falciparum. We emphasize that elacridar is a third-generation ABC transporters inhibitor, never tested before on malaria parasites. In vitro experiments were performed on asexual stages of two strains of P. falciparum, chloroquine-sensitive (D10) and chloroquine-resistant (W2). Incubation times on asynchronous or synchronous cultures were 72h or 96h, respectively. The antiplasmodial effect (i.e. the IC50) was determined by measuring the activity of the parasite lactate dehydrogenase, while the interaction between drugs was determined through combination index (CI) analyses. Elacridar achieved an IC50 concentration comparable to that of ivermectin, approx. 10-fold lower than that of verapamil, the other tested ABC transporter inhibitor. CI results showed synergistic effect of verapamil plus doxycycline, which is coherent with the starting hypothesis, i.e. that ABC transporters represent potential targets, worth of further investigations, towards the development of companion molecules useful to enhance the efficacy of antimalarial drugs. At the same time, the observed antagonistic effect of doxycycline in combination with ivermectin or elacridar highlighted the importance of drug testing, to avoid the de-facto generation of a sub-dosage, a condition that facilitates the development of drug resistance.

Project description:BackgroundLoop-mediated isothermal amplification (LAMP) for malaria diagnosis at the point of care (POC) depends on the detection capacity of synthesized nucleic acids and the specificity of the amplification target. To improve malaria diagnosis, new colorimetric LAMP tests were developed using multicopy targets for Plasmodium vivax and Plasmodium falciparum detection.MethodsThe cytochrome oxidase I (COX1) mitochondrial gene and the non-coding sequence Pvr47 for P. vivax, and the sub-telomeric sequence of erythrocyte membrane protein 1 (EMP1) and the non-coding sequence Pfr364 for P. falciparum were targeted to design new LAMP primers. The limit of detection (LOD) of each colorimetric LAMP was established and assessed with DNA extracted by mini spin column kit and the Boil & Spin method from 28 microscopy infections, 101 malaria submicroscopic infections detected by real-time PCR only, and 183 negatives infections by both microscopy and PCR.ResultsThe LODs for the colorimetric LAMPs were estimated between 2.4 to 3.7 parasites/µL of whole blood. For P. vivax detection, the colorimetric LAMP using the COX1 target showed a better performance than the Pvr47 target, whereas the Pfr364 target was the most specific for P. falciparum detection. All microscopic infections of P. vivax were detected by PvCOX1-LAMP using the mini spin column kit DNA extraction method and 81% (17/21) were detected using Boil & Spin sample preparation. Moreover, all microscopic infections of P. falciparum were detected by Pfr364-LAMP using both sample preparation methods. In total, PvCOX1-LAMP and Pfr364-LAMP detected 80.2% (81 samples) of the submicroscopic infections using the DNA extraction method by mini spin column kit, while 36.6% (37 samples) were detected using the Boil & Spin sample preparation method.ConclusionThe colorimetric LAMPs with multicopy targets using the COX1 target for P. vivax and the Pfr364 for P. falciparum have a high potential to improve POC malaria diagnosis detecting a greater number of submicroscopic Plasmodium infections.

Dataset Information

A 4-cyano-3-methylisoquinoline inhibitor of Plasmodium falciparum growth targets the sodium efflux pump PfATP4.

Publications

A 4-cyano-3-methylisoquinoline inhibitor of Plasmodium falciparum growth targets the sodium efflux pump PfATP4.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets