Plasmodium falciparum: hyperoxic vs normoxic conditions
Ontology highlight
ABSTRACT:
ORGANISM(S): Plasmodium falciparum 3D7 Plasmodium falciparum
PROVIDER: GSE18831 | GEO | 2009/10/30
SECONDARY ACCESSION(S): PRJNA121167
REPOSITORIES: GEO
Similar Datasets
Project description:Transcriptional profiling of P. falciparum comparing parasites exposed to 5% and 21% oxygen environmental conditions in the late ring stage. Two experimental conditions: 5% vs 21%. Biological replicates: 3 normoxia and 3 hyperoxia replicates
2010-06-20 | E-GEOD-18831 | biostudies-arrayexpress
Project description:Control of malaria is threatened by emerging parasite resistance to artemisinin drug (ART) therapies. The molecular details of how Plasmodium malaria parasites response to ART and how this relates to resistance is not clear. To determine how parasites respond to ART by altering gene expression, we performed a transcriptomic study of dihydroartemisinin (DHA) response in P. falciparum K1 strain and in P. berghei ANKA strain. Microarray data from DHA-treated P. falciparum trophozoite stage parasites were compared with data from other ART treatments. Genes with consistent changes in expression were identified, which includes notably down-regulation of cytosolic ribosomal protein genes. RNA-seq data revealed a similar pattern of transcriptomic change, although the pattern was much clearer in that more than one-third of P. falciparum trophozoite genes are differentially expressed with greater statistical support for down-regulation of ribosomal protein genes. The poor overlap of differentially-expressed genes between microarray and RNA-seq and less-well defined patterns for the former suggests that the accuracy of microarray is limited by technological bias. The trophozoite response to DHA is overall “ring-like” and less “trophozoite-like”, which is consistent with previous findings that Plasmodium can enter a quiescent ring-like state to resist ART. RNA-seq data from DHA-treated P. falciparum rings reveal a more muted response, although there is considerable overlap of differentially expressed genes with DHA-treated trophozoites. In contrast, P. falciparum schizonts are unresponsive to DHA, suggesting that the protective response acts mainly to arrest parasite development through the G2/M checkpoint. The transcriptional response of P. berghei to DHA treatment in vivo in infected mice is strikingly similar to the P. falciparum in vitro ring and trophozoite responses, in which ribosomal protein genes are notably down-regulated. These results suggest Plasmodium species respond to DHA in the same way. This knowledge could be applied to outwit the parasite to deliver more effective artemisinin therapies, and maybe hinder the development of drug resistance.
2015-10-15 | GSE62132 | GEO
Project description:Plasmodium falciparum is the main causative agent of human malaria. During the intraerythrocytic development cycle, P. falciparum morphology changes dramatically from circulating young rings to sequestered mature trophozoites and schizonts. Sequestered forms contribute to the pathophysiology of severe malaria as the infected erythrocytes obstruct the microvascular flow in deep organs and induce local inflammation. However, the sequestration mechanism limits the access to the corresponding parasitic form in clinical samples from patients infected with P. falciparum. To complement this deficiency, we aimed to evaluate the relevance of mRNA study as a proxy of protein expression in sequestered parasites. To do so, we conducted a proteotranscriptomic analysis using five independent P. falciparum laboratory strains samples. RNA sequencing was performed on circulating ring stage parasites and LC-MS/MS on the corresponding sequestered mature forms. All analyzes were performed within the same development cycle for direct individual correlation. mRNA expression level was assessed at the circulating ring stage and the corresponding protein expression level was measured after 18h-24h of maturation to reach the mature trophozoite stage. Overall, our results showed a strong transcriptome/transcriptome and proteome/proteome correlation between samples. Moreover, strong correlations of mRNA and proteins expressions levels were found between ring stage transcriptomes and mature forms proteomes. However, twice more transcripts were identified at ring stage than proteins at mature trophozoite stage. A high level of transcript expression did not guarantee the detection of the corresponding protein. Finally, we pointed out discrepancies at the individual gene level. Taken together, our results show that transcripts and proteins expression are overall correlated. However, mRNA abundance is not a perfect proxy of protein expression at the individual level. Importantly, our study shows limitations of the “blind” use of RNA-seq and the importance of multi-omics approaches for P. falciparum blood stage study in clinical samples.
2020-06-17 | GSE152608 | GEO
Project description:Background: Host iron deficiency is protective against severe malaria as the human malaria parasite Plasmodium falciparum depends on free iron from its host to proliferate. Due to the absence of transferrin, ferritin, ferroportin, and a functional heme oxygenase, the parasite’s essential pathways of iron acquisition, storage, export, and detoxification differ from those in humans and may thus be excellent targets for therapeutic development. However, the proteins involved in these processes in P. falciparum remain largely unknown. Experimental design: To identify iron-regulated mechanisms and putative iron transporters in the human malaria parasite Plasmodium falciparum 3D7, we carried out whole-transcriptome profiling using bulk RNA-sequencing. The parasites were cultured either using erythrocytes from a donors with high, medium (healthy) or low iron status (experiment 1); or with red blood cells from another healthy donor in the presence or absence of 0.7 µM hepcidin, a specific ferroportin inhibitor and iron-regulatory hormone (experiment 2). This concentration of hepcidin was reported to reduce binding of ferrous iron to ferroportin by 50% in vitro (39). Samples from three biological replicates each were harvested at the ring and trophozoite stage (6 – 9 and 26 – 29 hours post invasion, hpi) during the second intra-erythrocytic developmental cycle under the conditions specified.
2024-04-08 | E-MTAB-13411 | biostudies-arrayexpress
Project description:For malaria transmission, the parasite must undergo sexual differentiation into mature gametocytes. However, the molecular basis for this critical transition in the parasites life cycle is unknown. Six previously uncharacterized genes, Pfg14.744, Pfg14.745, Pfg14.748, Pfg14.763, Pfg14.752 and Pfg6.6 that are members of a 36 gene Plasmodium falciparum-specific subtelomeric superfamily were found to be expressed in parasites that are committed to sexual development as suggested by co-expression of Pfs16 and Pfg27. Northern blots demonstrated that Pfg14.744 and Pfg14.748 were first expressed before the parasites differentiated into morphologically distinct gametocytes, transcription continued to increase until stage II gametocytes were formed and then rapidly decreased. Immunofluorescence assays indicated that both proteins were only produced in the subpopulation of ring stage parasites that are committed to gametocytogenesis and both localized to the parasitophorous vacuole (PV)b of the early ring stage parasites. As the parasites continued to develop Pfg14.748 remained within the parasitophorous vacuole, while Pfg14.744 was detected in the erythrocyte. The 5' flanking region of either gene alone was sufficient to drive early gametocyte specific expression of green fluorescent protein (GFP). In parasites transfected with a plasmid containing the Pfg14.748 5' flanking region immediately upstream of GFP, fluorescence was observed in a small number of schizonts the cycle before stage I gametocytes were observed. This expression pattern is consistent with commitment to sexual differentiation prior to merozoite release and erythrocyte invasion. Further investigation into the role of these genes in the transition from asexual to sexual differentiation could provide new strategies to block malaria transmission. Microarray analysis was used to compare two clones derived from Plasmodium falciparum strain 3D7 parasites that differ in their ability to undergo gametocytogenesis. Clone G+ produces gametocytes and clone G- produces very few if any gametocytes. RNA was harvested from the cultures when the asexual parasitemia was 0.9-1.48% (day 4) (n=4) after setting up the gametocyte cultures and 5.2-5.58% (day 6) (n=4) prior to the appearance of morphologically distinct gametocytes and used to generate cDNA that was labeled with Cy3 or Cy5 and hybridized to the Plasmodium falciparum 70 mer oligonucleotide microarray developed by DeRisi and co-workers.
2014-10-16 | E-GEOD-62364 | biostudies-arrayexpress
Project description:Plasmodium falciparum cellline experiment: CD36 panned clones (Ring) were hybridized against S8.4 (Ring)
2007-04-25 | E-MEXP-439 | biostudies-arrayexpress
Project description:Plasmodium falciparum blood stage parasites: control vs PfTRF-depleted parasites
| PRJNA328971 | ENA
Project description:Whole transcriptome analysis of rosetting Plasmodium falciparum parasites
| PRJNA140507 | ENA
Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with WR99210 RNA from P. falciparum Dd2 and B1G9 (WR99210 resistant cell-line) trophozoites that had been treated with 10 nM WR99210 for varying durations (3, 6, 9, 15, 18, 21 and 24h) was hybridized against a common pool of trophozoite RNA from a cognate clone, a culture containing 0.1% (v/v) DMSO lacking drug was used as untreated control, microarray data were obtained from at least four hybridizations using RNA from two independent parasite cultures
2008-11-14 | E-GEOD-9724 | biostudies-arrayexpress
Project description:The microarray experiments were carried out using a long oligonucleotide DNA microarray that represent all 5363 P. falciparum genes with one oligonucleotide per 1.9kb of coding sequence on average (Hu et al. 2007). Total 247 microarray experiments were carried out including 29-drug treatment time courses with 20 compounds and corresponding untreated controls from different drug or inhibitor treatment. Data of each drug/inhibitor experiment were normalized using a linear normalization and background filtering as implemented by the NOMAD database (http://derisilab.ucsf.edu). Time-series sampling and experiments with synchronized ex vivo culturing parasites. Each experiment has treatment and controls, and starts at a specific time of post invasion. For an example of quinine treatment, the treatments start from late ring stage through trophozoite stage of the parasites. First, IC50 is determined by drug assay with synchronized parasites (5% parasiteomia and 2% RBC). Second, synchronized parasite cultures are splitted into 12 flasks (75ml culture/flask) for a 6 time-point time-series experiment. 6 flasks are treated with quinine (final concentration is IC50) and 6 flasks are negative controls. 1,2,4,6,8 and 10 hrs after the treatment, parasites in each flask were harvested for total RNA isolation and microarray hybridizaiton.
2010-05-18 | E-GEOD-19468 | biostudies-arrayexpress