Project description:Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programs around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline based drugs is becoming critical. So far only few resistance markers have been identified and verified from which only two ABC transmembrane transporters namely PfMDR1 and PfCRT have been experimentally verified. Another P. falciparum ABC transporter, the multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identify a parasite clone that is derived from the 3D7 P. falciparum strain and which shows increased resistance to chloroquine and mefloquine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5M-bM-^@M-^Y upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription that result in increased levels of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of such genetic polymorphisms to underlie drug resistance phenotypes. Presented here are the data from microarray-based genome-wide transcriptomic and genomic studies of the drug-sensitive and drug-resistant 3D7 clones 11C/wt and 6A/mut. 2 P. falciparum lab clones derived from 3D7 strain were harvested during the intra-erythrocytic cycle for genomic DNA. gDNA were extracted by phenol chloroform. Synthesis of labelled target DNA was carried out as previously described: Bozdech, Z., M. Llinas, B. L. Pulliam, E. D. Wong, J. Zhu & J. L. DeRisi, (2003) The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 1: E5, and used in comparative genomic microarray hybridizations (CGH).
Project description:Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programs around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline based drugs is becoming critical. So far only few resistance markers have been identified and verified from which only two ABC transmembrane transporters namely PfMDR1 and PfCRT have been experimentally verified. Another P. falciparum ABC transporter, the multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identify a parasite clone that is derived from the 3D7 P. falciparum strain and which shows increased resistance to chloroquine and mefloquine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5M-bM-^@M-^Y upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription that result in increased levels of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of such genetic polymorphisms to underlie drug resistance phenotypes. Presented here are the data from microarray-based genome-wide transcriptomic and genomic studies of the drug-sensitive and drug-resistant 3D7 clones 11C/wt and 6A/mut. 2 P. falciparum lab clones derived from 3D7 strain were harvested during the intra-erythrocytic cycle at 8hr intervals over 48 hours to obtain a total of 6 time point samples per clone. RNA from a total of 12 samples were extracted. Synthesis of target DNA was carried out as described in Bozdech, Z., S. Mok & A. P. Gupta, (2013) DNA microarray-based genome-wide analyses of Plasmodium parasites. Methods in molecular biology 923: 189-211 and used in replicate microarray hybridizations against a common RNA reference pool of 3D7 strain.
Project description:Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programs around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline based drugs is becoming critical. So far only few resistance markers have been identified and verified from which only two ABC transmembrane transporters namely PfMDR1 and PfCRT have been experimentally verified. Another P. falciparum ABC transporter, the multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identify a parasite clone that is derived from the 3D7 P. falciparum strain and which shows increased resistance to chloroquine and mefloquine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5’ upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription that result in increased levels of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of such genetic polymorphisms to underlie drug resistance phenotypes. Presented here are the data from microarray-based genome-wide transcriptomic and genomic studies of the drug-sensitive and drug-resistant 3D7 clones 11C/wt and 6A/mut.
Project description:Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programs around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline based drugs is becoming critical. So far only few resistance markers have been identified and verified from which only two ABC transmembrane transporters namely PfMDR1 and PfCRT have been experimentally verified. Another P. falciparum ABC transporter, the multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identify a parasite clone that is derived from the 3D7 P. falciparum strain and which shows increased resistance to chloroquine and mefloquine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5’ upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription that result in increased levels of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of such genetic polymorphisms to underlie drug resistance phenotypes. Presented here are the data from microarray-based genome-wide transcriptomic and genomic studies of the drug-sensitive and drug-resistant 3D7 clones 11C/wt and 6A/mut.
Project description:Drug resistance in Plasmodium falciparum is an important public health burden since it reverses the malaria control achieved so far. Understanding the mechanism of drug resistance will help us to develop novel drug/vaccine targets for malaria treatment. In the present study, we have used the whole transcriptome sequencing to characterize the transcriptional difference between chloroquine sensitive and resistant P. falciparum strains (3D7 and Dd2). The differential gene expression between these strains was analyzed to understand their phenotypic properties like drug sensitivity, immune evasion and pathways involved.
Project description:This SuperSeries is composed of the following subset Series: GSE25878: Artemisinin resistance in Plasmodium falciparum is associated with an altered temporal pattern of transcription (expression) GSE25879: Artemisinin resistance in Plasmodium falciparum is associated with an altered temporal pattern of transcription (CGH) Refer to individual Series
Project description:Bazzani2012 - Genome scale networks of P.falciparum and human hepatocyte
This model is described in the article:
Network-based assessment of the selectivity of metabolic drug targets in Plasmodium falciparum with respect to human liver metabolism.
Bazzani S, Hoppe A, Holzhütter HG.
BMC Syst Biol.
2012 Aug 31;6(1):118. PMID: 2937810
Abstract:
ABSTRACT:
BACKGROUND: The search for new drug targets for antibiotics against Plasmodium falciparum, a major cause of human deaths, is a pressing scientific issue, as multiple resistance strains spread rapidly. Metabolic network-based analyses may help to identify those parasite's essential enzymes whose homologous counterparts in the human host cells are either absent, non-essential or relatively less essential.
RESULTS:
Using the well-curated metabolic networks PlasmoNet of the parasite Plasmodium falciparum and HepatoNet1 of the human hepatocyte, the selectivity of 48 experimental antimalarial drug targets was analyzed. Applying in silico gene deletions, 24 of these drug targets were found to be perfectly selective, in that they were essential for the parasite but non-essential for the human cell. The selectivity of a subset of enzymes, that were essential in both models, was evaluated with the reduced fitness concept. It was, then, possible to quantify the reduction in functional fitness of the two networks under the progressive inhibition of the same enzymatic activity. Overall, this in silico analysis provided a selectivity ranking that was in line with numerous in vivo and in vitro observations.
CONCLUSIONS:
Genome-scale models can be useful to depict and quantify the effects of enzymatic inhibitions on the impaired production of biomass components. From the perspective of a host-pathogen metabolic interaction, an estimation of the drug targets-induced consequences can be beneficial for the development of a selective anti-parasitic drug.
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To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. PMID: 20587024
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Project description:The combination therapy of the Artemisinin-derivative Artemether (ART) with Lumefantrine (LM) (Coartem®) is an important malaria treatment regimen in many endemic countries. Resistance to Artemisinin has already been reported, and it is feared that LM resistance (LMR) could also evolve quickly. Therefore molecular markers which can be used to track Coartem®efficacy are urgently needed. Often, stable resistance arises from initial, unstable phenotypes that can be identified in vitro. Here we have used the Plasmodium falciparum multidrug resistant reference strain V1S to induce LMR in vitro by culturing the parasite under continuous drug pressure for 16 months. The initial IC50 (inhibitory concentration that kills 50% of the parasite population) was 24 nM. The resulting resistant strain V1SLM, obtained after culture for an estimated 166 cycles under LM pressure, grew steadily in 378 nM of LM; this corresponds to 15 times the IC50 of the parental strain. However, after two weeks of culturing V1SLM in drug-free medium, the IC50 returned to that of the initial, parental strain V1S. This transient drug tolerance was associated with major changes in gene expression profiles: when we explored V1SLM using the PFSANGER Affymetrix custom array, we identified 184 differentially expressed (DE) genes; amongst those 18 putative transporters including the multidrug resistance gene (pfmdr1), the multidrug resistance associated protein (pfmrp1) and the V-type H+ pumping pyrophosphatase 2 (pfvp2). Moreover, our results showed significant enrichment of genes associated with fatty acid metabolism and a clear selective advantage for two genomic loci in parasites grown under LM drug pressure, suggesting these genes may contribute to LM response in P. falciparum and could prove useful as molecular markers to monitor LM susceptibility.