Disruption of the coordination between host circadian rhythms and malaria parasite development alters the duration of the intraerythrocytic cycle

Mapping Intimacies ◽

10.1101/791046 ◽

2019 ◽

Cited By ~ 1

Author(s):

Amit K. Subudhi ◽

Aidan J. O’Donnell ◽

Abhinay Ramaprasad ◽

Hussein M. Abkallo ◽

Abhinav Kaushik ◽

...

Keyword(s):

Parasite Development ◽

Developmental Cycle ◽

Plasmodium Chabaudi ◽

Malaria Parasites ◽

Multiple Processes ◽

Free Running ◽

Fitness Benefits ◽

Circadian Transcription

Malaria parasites complete their intra-erythrocytic developmental cycle (IDC) in multiples of 24 hours (depending on the species), suggesting a circadian basis to the asexual cell cycle, but the mechanism controlling this periodicity is unknown. Combining in vivo and in vitro approaches using rodent and human malaria parasites, we reveal that: (i) 57% of Plasmodium chabaudi genes exhibit 24 h “circadian” periodicity in transcription; (ii) 58% of these genes lose transcriptional rhythmicity when the IDC is out-of-synchrony with host rhythms; (iii) 9% of Plasmodium falciparum genes show circadian transcription under free-running conditions; (iv) Serpentine receptor 10 (SR10) has a circadian transcription profile and disrupting it in rodent malaria parasites shortens the IDC by 2-3 hours; (v) Multiple processes including DNA replication and the ubiquitin and proteasome pathways are affected by loss of coordination with host rhythms and by disruption of SR10. Our results show that malaria parasites are at least partly responsible for scheduling their IDCs explaining the fitness benefits of coordination with host rhythms.

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Ex VivoMaturation Assay for Testing Antimalarial Sensitivity of Rodent Malaria Parasites

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01292-16 ◽

2016 ◽

Vol 60 (11) ◽

pp. 6859-6866 ◽

Cited By ~ 4

Author(s):

Zi Wei Chang ◽

Benoit Malleret ◽

Bruce Russell ◽

Laurent Rénia ◽

Carla Claser

Keyword(s):

Ex Vivo ◽

Single Step ◽

Parasite Development ◽

Ring Stage ◽

Malaria Parasites ◽

Rodent Malaria ◽

Content Type ◽

Parasite Biology

ABSTRACTEx vivoassay systems provide a powerful approach to studying human malaria parasite biology and to testing antimalarials. For rodent malaria parasites, short-termin vitroculture andex vivoantimalarial susceptibility assays are relatively cumbersome, relying onin vivopassage for synchronization, since ring-stage parasites are an essential starting material. Here, we describe a new approach based on the enrichment of ring-stagePlasmodium berghei,P. yoelii, andP. vinckei vinckeiusing a single-step Percoll gradient. Importantly, we demonstrate that the enriched ring-stage parasites develop synchronously regardless of the parasite strain or species used. Using a flow cytometry assay with Hoechst and ethidium or MitoTracker dye, we show that parasite development is easily and rapidly monitored. Finally, we demonstrate that this approach can be used to screen antimalarial drugs.

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Synergy of Human Immunodeficiency Virus Protease Inhibitors with Chloroquine against Plasmodium falciparum In Vitro and Plasmodium chabaudi In Vivo

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01329-07 ◽

2008 ◽

Vol 52 (7) ◽

pp. 2653-2656 ◽

Cited By ~ 20

Author(s):

Zhengxiang He ◽

Li Qin ◽

Lili Chen ◽

Nanzheng Peng ◽

Jianlan You ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Plasmodium Falciparum ◽

Protease Inhibitors ◽

Plasmodium Chabaudi ◽

Malaria Parasites ◽

Human Immunodeficiency Virus Protease ◽

Immunodeficiency Virus ◽

Antimalarial Action

ABSTRACT The synergy of the activities between chloroquine and various human immunodeficiency virus protease inhibitors was investigated in chloroquine-resistant and -sensitive malaria parasites. In both in vitro and in vivo assay systems, ritonavir was found to be the most potent in potentiating the antimalarial action of chloroquine.

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Signalome-wide assessment of erythrocyte response to Plasmodium reveals novel targets for host-directed antimalarial intervention

10.1101/2020.06.09.143206 ◽

2020 ◽

Author(s):

Jack D. Adderley ◽

Simona John von Freyend ◽

Sarah A. Jackson ◽

Megan J. Bird ◽

Amy L. Burns ◽

...

Keyword(s):

Signaling Pathways ◽

Dynamic Assessment ◽

Growth Factor Receptor ◽

Cell Types ◽

Parasite Development ◽

Antibody Microarray ◽

Malaria Parasites ◽

The Status

AbstractIntracellular pathogens are known to mobilise host signaling pathways to manipulate gene expression in their host cell to promote their own survival. Surprisingly, evidence is emerging that specific signal transduction elements are activated in a-nucleated erythrocytes in response to infection with malaria parasites, but the extent of this phenomenon remains unknown. Here, we fill this knowledge gap by providing a comprehensive and dynamic assessment of host erythrocyte signaling during the course of infection with Plasmodium falciparum. We used an antibody microarray that comprises 878 antibodies directed against human signaling proteins, >600 of which are phospho-specific, to interrogate the status of host erythrocyte signaling pathways at three stages of parasite development during the asexual cycle. This confirmed the pre-existing fragmentary data on the activation of a PAK-MEK pathway, and revealed the modulation of a large number of additional signaling elements during infection.We focussed on the receptor tyrosine kinase c-MET, also known as the hepatocyte growth factor receptor, and the MAP kinase pathway component B-Raf that is reported to lie downstream of c-MET in a number of cell types. Array data validated by Western blotting revealed that activation sites of c-MET are phosphorylated in trophozoite-infected erythrocytes, and we show that treatment of parasite cultures with c-MET or B-Raf selective inhibitors have nanomolar potency against in vitro proliferation of P. falciparum and the phylogenetically distant species P. knowlesi. Furthermore, we demonstrate that a c-MET inhibitor impairs in vivo proliferation of the rodent malaria parasite P. berghei in mice.Overall, we provide a comprehensive dataset on the modulation of host erythrocyte signaling during infection with malaria parasites, as well as a proof of concept that human signaling kinases identified as activated by malaria infection represent attractive targets for antimalarial intervention.

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Plasmodium chabaudi: a rodent malaria model for in-vivo and in-vitro cytoadherence of malaria parasites in the absence of knobs

Parasite Immunology ◽

10.1111/j.1365-3024.1987.tb00529.x ◽

1987 ◽

Vol 9 (5) ◽

pp. 543-561 ◽

Cited By ~ 31

Author(s):

J. COX ◽

S. SEMOFF ◽

M. HOMMEL

Keyword(s):

Plasmodium Chabaudi ◽

Malaria Parasites ◽

Rodent Malaria ◽

Malaria Model

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The in vivo distribution and dynamics of DNA topoisomerase II in Drosophila embryonic nuclei and chromosomes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146217 ◽

1993 ◽

Vol 51 ◽

pp. 74-75

Author(s):

Jason R. Swedlow ◽

Neil Osheroff ◽

Tim Karr ◽

John W. Sedat ◽

David A. Agard

Keyword(s):

Topoisomerase Ii ◽

Biochemical Characterization ◽

Developmental Cycle ◽

Dna Topoisomerase Ii ◽

Chromosomal Distribution ◽

Dna Topoisomerase ◽

Ideal System ◽

Dnase Treatment

DNA topoisomerase II is an ATP-dependent double-stranded DNA strand-passing enzyme that is necessary for full condensation of chromosomes and for complete segregation of sister chromatids at mitosis in vivo and in vitro. Biochemical characterization of chromosomes or nuclei after extraction with high-salt or detergents and DNAse treatment showed that topoisomerase II was a major component of this remnant, termed the chromosome scaffold. The scaffold has been hypothesized to be the structural backbone of the chromosome, so the localization of topoisomerase II to die scaffold suggested that the enzyme might play a structural role in the chromosome. However, topoisomerase II has not been studied in nuclei or chromosomes in vivo. We have monitored the chromosomal distribution of topoisomerase II in vivo during mitosis in the Drosophila embryo. This embryo forms a multi-nucleated syncytial blastoderm early in its developmental cycle. During this time, the embryonic nuclei synchronously progress through 13 mitotic cycles, so this is an ideal system to follow nuclear and chromosomal dynamics.

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Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽

10.1182/blood.v76.6.1250.1250 ◽

1990 ◽

Vol 76 (6) ◽

pp. 1250-1255 ◽

Cited By ~ 36

Author(s):

S Whitehead ◽

TE Peto

Keyword(s):

Plasmodium Falciparum ◽

Growth Inhibition ◽

Antimalarial Activity ◽

Clinical Malaria ◽

Inhibitory Effect ◽

Parasite Development ◽

And Control ◽

Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

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The Effects of Polyamine Analogues on Malaria Parasites In Vitro and In Vivo

Progress in Polyamine Research - Advances in Experimental Medicine and Biology ◽

10.1007/978-1-4684-5637-0_63 ◽

1988 ◽

pp. 717-726 ◽

Cited By ~ 4

Author(s):

Alan J. Bitonti ◽

Peter P. McCann ◽

Albert Sjoerdsma

Keyword(s):

Malaria Parasites ◽

Polyamine Analogues

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Mammalian deubiquitinating enzyme inhibitors display in vitro and in vivo activity against malaria parasites and potentiate artemisinin action

10.1101/2020.08.13.249425 ◽

2020 ◽

Author(s):

Nelson V. Simwela ◽

Katie R. Hughes ◽

Michael T. Rennie ◽

Michael P. Barrett ◽

Andrew P. Waters

Keyword(s):

Anticancer Agents ◽

Drug Targets ◽

Reverse Genetics ◽

Enzyme Inhibitors ◽

Artemisinin Resistance ◽

Drug Repurposing ◽

Antimalarial Drugs ◽

Malaria Parasites

AbstractCurrent malaria control efforts rely significantly on artemisinin combinational therapies which have played massive roles in alleviating the global burden of the disease. Emergence of resistance to artemisinins is therefore, not just alarming but requires immediate intervention points such as development of new antimalarial drugs or improvement of the current drugs through adjuvant or combination therapies. Artemisinin resistance is primarily conferred by Kelch13 propeller mutations which are phenotypically characterised by generalised growth quiescence, altered haemoglobin trafficking and downstream enhanced activity of the parasite stress pathways through the ubiquitin proteasome system (UPS). Previous work on artemisinin resistance selection in a rodent model of malaria, which we and others have recently validated using reverse genetics, has also shown that mutations in deubiquitinating enzymes, DUBs (upstream UPS component) modulates susceptibility of malaria parasites to both artemisinin and chloroquine. The UPS or upstream protein trafficking pathways have, therefore, been proposed to be not just potential drug targets, but also possible intervention points to overcome artemisinin resistance. Here we report the activity of small molecule inhibitors targeting mammalian DUBs in malaria parasites. We show that generic DUB inhibitors can block intraerythrocytic development of malaria parasites in vitro and possess antiparasitic activity in vivo and can be used in combination with additive effect. We also show that inhibition of these upstream components of the UPS can potentiate the activity of artemisinin in vitro as well as in vivo to the extent that ART resistance can be overcome. Combinations of DUB inhibitors anticipated to target different DUB activities and downstream 20s proteasome inhibitors are even more effective at improving the potency of artemisinins than either inhibitors alone providing proof that targeting multiple UPS activities simultaneously could be an attractive approach to overcoming artemisinin resistance. These data further validate the parasite UPS as a target to both enhance artemisinin action and potentially overcome resistance. Lastly, we confirm that DUB inhibitors can be developed into in vivo antimalarial drugs with promise for activity against all of human malaria and could thus further exploit their current pursuit as anticancer agents in rapid drug repurposing programs.Graphical abstract

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Characterization of a Chlamydia psittaciDNA Binding Protein (EUO) Synthesized during the Early and Middle Phases of the Developmental Cycle

Infection and Immunity ◽

10.1128/iai.66.3.1167-1173.1998 ◽

1998 ◽

Vol 66 (3) ◽

pp. 1167-1173 ◽

Cited By ~ 31

Author(s):

Li Zhang ◽

Annemarie L. Douglas ◽

Thomas P. Hatch

Keyword(s):

Promoter Region ◽

Chlamydia Psittaci ◽

Host Cells ◽

Upstream Open Reading Frame ◽

Developmental Cycle ◽

Binding Property ◽

Logarithmic Growth Phase ◽

Reading Frame

ABSTRACT The EUO gene (for early upstream open reading frame) ofChlamydia psittaci was previously found to be transcribed better at 1 than at 24 h postinfection. We found that the EUO gene encodes a minor protein that is expressed within 1 h of infection of host cells with C. psittaci 6BC but that protein quantity peaks during the logarithmic growth phase of reticulate bodies (RBs), declines late in the infection (after 20 h) when RBs reorganize into elementary bodies (EBs), and is absent in infectious EBs. EUO protein lacks homology to known proteins but does contain a putative helix-turn-helix motif. We found that recombinant EUO binds to DNA in vitro with a relatively broad specificity. Using the bp −200 to +67 promoter region of the cysteine-rich envelope protein (crp) operon as a model, we show that EUO protein preferentially binds to AT-rich sequences and protects crpDNA from DNase I from approximately bp −60 to −9. We also found that native EUO protein in extracts of RBs binds to the promoter region of the crp operon, demonstrating that the DNA binding property of EUO protein is not an artifact of recombinant methods. Although EUO protein appears to bind to the crp operon with high affinity in vitro (Kd of about 15 nM), it is not known whether the protein binds the crp DNA in vivo.

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