Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1066233 | ENA |
REPOSITORIES: ENA
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Project description:Concerns about impending failure of artemisinin compounds (ART) have grown with global use of ART-based combination therapy (ACT) against malaria. WHO has defined Plasmodium falciparum resistance to ART as prolonged parasite clearance half-life in vivo (t1/2) plus the presence of certain K13 Kelch-propeller substitutions, e.g. C580Y. Recrudescences and fever clearance times after ART monotherapy, however, have not correlated well with these criteria. We have crossed K13 C580 wild-type and 580Y-mutant parasites for ART studies in Aotus. Artesunate treated C580- but not 580Y-infections recrudesced requiring retreatment, and K13 type had little or no effect on t1/2. These results challenge K13 and t1/2 variations as markers of increased resistance to ART per se and emphasize the need for effective partner drugs in ACTs.
2019-02-11 | GSE78689 | GEO
Project description:The objective of our study is to characterize gene expression signatures associated with in vivo artemisinin-resistance phenotype in this large-scale genome-wide association study. To achieve this goal, we employed microarray technology to establish the global gene expression profiles of isolates sampled from 1043 patients, of whom after treatment with ACTs (artemisinin combination therapy) displayed differential rates of parasite clearance. P. falciparum isolates were sampled from the whole blood of 1043 malaria-infected patients prior to ACT treatment. Sampling was done across 14 field sites spanning across South East Asia (Pailin, Pursat, Preah Vihear, Rattanakiri in Cambodia; Mae Sot, Srisakhet, Khun Han, Ranong in Thailand; Shwe Kyin in Myanmar; Binh Phuoc in Vietnam; Attapeu in Laos), to Bangladesh and African DR Congo from 2010 to 2012. RNA were extracted and synthesis and amplification 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 (PMID 22990779), to generate sufficient material for hybridizations against a common RNA reference pool of 3D7 strain using a microarray platform.
2014-07-15 | E-GEOD-59097 | biostudies-arrayexpress
Project description:The objective of this study is to characterize the gene expression signatures associated with in vivo artemisinin resistance phenotype and its transcriptional response to Artemisinin Combination Therapy (ACT) or Triple artemisinin combination therapy (TACT). Using stranded RNA-seq protocol expression profiles of Plasmodb annotated transcripts along with anti-sense, alternatively spliced and non-coding isoforms expressed in clinical isolates were generated for 310 pre-treated, 300 post-treated and 24 timepoints from the intra-erythrocyte development cycle.
2024-09-30 | GSE242548 | GEO
Project description:The objective of this study is to characterize gene expression signatures associated with in vivo artemisinin resistance phenotype and its transcriptional response to Artemisinin Combination Therapy (ACT) treatment . RNA-seq was applied to establish the global gene expression profiles for 196 and 180 isolates sampled from patients prior to and post to ACT treatment.
2022-02-07 | GSE169520 | GEO
Project description:The objective of this study is to characterize gene expression signatures associated with in vivo artemisinin resistance phenotype and its transcriptional response to Artemisinin Combination Therapy (ACT) treatment . To achieve this goal, we employed microarray technology to establish the global gene expression profiles of isolates sampled from 680 patients prior to ACT treatment and 659 patients after the ACT treament.
2021-11-04 | GSE149735 | GEO
Project description:Malaria parasites induce morphological and biochemical changes in the membranes of parasite-infected red blood cells (iRBCs) for propagation. Artemisinin combination therapies are the first-line antiplasmodials in endemic countries. However, the mechanism of action of artemisinin is unclear, and drug resistance decreases long-term efficacy. To understand whether artemisinin targets or interacts with iRBC membrane proteins, this study investigated the molecular changes caused by dihydroartemisin (DHA), an artemisinin derivative, in Plasmodium falciparum 3D7 using a combined transcriptomic and membrane proteomic profiling approach.
2022-02-15 | PXD028062 | Pride
Project description:Evolving resistance to artemisinin-based compounds in SE Asia threatens to derail attempts to control and eliminate malaria. Resistance has been confirmed in western Cambodia, has recently emerged in western Thailand, but is absent from neighboring Laos. Artemisinin resistance results in reduced parasite clearance rates (CR) from the blood following treatment. We used a two-phase approach to identify the genes underlying this ongoing selective event. Comparison of geographical differentiation and haplotype structure at 6,969 polymorphic SNPs in 91 parasites from western Cambodia, western Thailand and Laos identified 33 strongly selected genome regions. We screened SNPs and microsatellites within these genome regions in 718 parasites from western Thailand, and identified a 35kb region of chr 13 showing strong association (P=10-6 to 10-11) with slow CR. This region contains several compelling candidate loci, such as HSP70, for assessment by transfection. These results illustrate the efficacy of targeted association for identifying the genetic basis of adaptive traits. 91 malaria parasite isolates assayed for single nucleotide polymorphisms across 45K loci
2012-04-30 | E-GEOD-33002 | biostudies-arrayexpress
Project description:Evolving resistance to artemisinin-based compounds in SE Asia threatens to derail attempts to control and eliminate malaria. Resistance has been confirmed in western Cambodia, has recently emerged in western Thailand, but is absent from neighboring Laos. Artemisinin resistance results in reduced parasite clearance rates (CR) from the blood following treatment. We used a two-phase approach to identify the genes underlying this ongoing selective event. Comparison of geographical differentiation and haplotype structure at 6,969 polymorphic SNPs in 91 parasites from western Cambodia, western Thailand and Laos identified 33 strongly selected genome regions. We screened SNPs and microsatellites within these genome regions in 718 parasites from western Thailand, and identified a 35kb region of chr 13 showing strong association (P=10-6 to 10-11) with slow CR. This region contains several compelling candidate loci, such as HSP70, for assessment by transfection. These results illustrate the efficacy of targeted association for identifying the genetic basis of adaptive traits.
2012-05-01 | GSE33002 | GEO
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.
2011-04-01 | E-TABM-1101 | biostudies-arrayexpress
Project description:Artemisinin resistance in Plasmodium falciparum malaria has emerged in western Cambodia. This is a major threat to global plans to control and eliminate malaria as the artemisinins are a key component of antimalarial treatment throughout the world. Using DNA microarrays we identify key features of a transcriptional profile that are associated with the delayed parasite clearance phenotype. These include reduced expression of several basic metabolic and cellular pathways in the early stages, and increased expression of essentially all functionalities associated with protein metabolism in the later stages of P. falciparum intraerythrocytic development. This is consistent with the reduced ring stage susceptibility that characterizes artemisinin resistant P. falciparum. This modulation of the P. falciparum intraerythrocytic transcriptome may result from differential expression of several regulatory proteins such as transcription factors of chromatin remodeling associated factors. In addition, the artemisinin resistant phenotype is strongly associated with a specific pattern of copy number variations, some of which are linked with differential expression of several regulatory proteins such as histone 4 and zinc permease. This study reports the first global transcriptional survey of artemisinin resistant parasites and provides a set of candidate genes for further investigation.
2010-12-07 | GSE25879 | GEO