Antimalarial and Plasmodium falciparum serpentine receptor 12 targeting effect of FDA approved purinergic receptor antagonist

Abstract

Intraerythrocytic stages of Plasmodium falciparum responsible for all clinical manifestations of malaria are regulated by array of signalling cascades that represent attractive targets for antimalarial therapy. G-protein coupled receptors (GPCRs) are druggable targets in the treatment of various pathological conditions, however, there is limited understanding about the role of GPCRs in malaria pathogenesis. In Plasmodium, serpentine receptors (PfSR1, PfSR10, PfSR12 and PfSR25) with GPCR-like membrane topology have been reported with the finite knowledge about their potential as antimalarial targets. We analyzed the localization of these receptors in malaria parasite by immunofluorescence assays. All four receptors were expressed in blood stages with PfSR12 expressing more in late intraerythrocytic stages. Further, we evaluated the druggability of PfSR12 using FDA-approved P2Y purinergic receptor antagonist, Prasugrel and its active metabolite R138727, which is proposed to be specific towards PfSR12. Interestingly, biophysical analysis indicated strong binding between PfSR12 and R138727 as compared to the prodrug Prasugrel. This binding interaction was further confirmed by thermal shift assay. Treatment of parasite with Prasugrel and R138727 resulted in growth inhibition of P. falciparum indicating an important role of purinergic signalling and PfSR12 in parasite survival. Next, progression studies indicated the inhibitory effect of Prasugrel begins in late erythrocyte stages corroborating with PfSR12 expression at these stages. Furthermore, Prasugrel also blocked in vivo growth of malaria parasite in a mouse experimental model. This study indicates the presence of P2Y type of purinergic signalling in growth and development of malaria parasite and suggests PfSR12, putative purinergic receptor druggability through Prasugrel.

Communicated by Ramaswamy H. Sarma

Keywords:

• Malaria
• Plasmodium falciparum
• purinergic signalling
• serpentine receptor
• PfSR12
• Prasugrel

Acknowledgements

We are grateful to Advanced Instrumentation Research Facility (AIRF), Jawaharlal Nehru University for confocal microscopy, Central Instrumentation Facility (CIF) of SCMM, JNU for flow cytometry and Animal House facility for animal experiments. The lab facility of Shiv Nadar University is also acknowledged. The authors would like to thank Jawaharlal Nehru University (JNU), New Delhi and Shiv Nadar University (SNU) for providing required lab facilities to conduct this research.

Disclosure statement

The authors declare no conflicts of interest.

Ethics approval

Animal studies were performed in accordance with guidelines of the Institutional Animal Ethics Committee (IAEC) of Jawaharlal Nehru University (JNU), Delhi and Committee for Control and Supervision of Experiments on Animals (CPCSEA), approved under strict accordance of ethical guidelines, approved by the animal ethics committee IAEC-JNU (iAec code no. 29/2018).

Data availability statement

All data supporting the findings of this study are available within the article.

Author’s contributions

S Singh conceived the project and SG, S Singh designed the experiments. SG, NJ, MS and SS performed laboratory experiments. SG analyzed the data and wrote the first draft of the manuscript. NJ did bioinformatics work. SG, AKN and S Singh critically evaluated the data and edited the manuscript.

Additional information

Funding

Funding from Science and Engineering Research Board (SERB) (EMR/2016/005644) and Drug and Pharmaceuticals Research Programme (DPRP) (Project No. P/569/2016-1/TDT) for S. Singh is acknowledged. S. Singh is a recipient of the IYBA Award from Department of Biotechnology (DBT). SG acknowledges University Grant Commission (UGC) for postdoctoral research fellowship. NJ and MS acknowledge Shiv Nadar Foundation for providing the Ph.D. fellowships. SS acknowledges ICMR-SRF (45/48/2019-PHA/BMS). The funders had no role in study design, analysis of results, preparation or publishing of the manuscript.