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: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. 6 P. falciparum parasites (field isolates) which are either Artemsinin resistant or sensitive from 3 study sites (Pailin in Cambodia, Xepon in Laos, Mae Sot in Thailand) were sampled and harvested for genomic DNA. gDNA from a total of 6 samples were extracted by phenol chloroform. Synthesis of labelled target DNA was carried out as previously described: Mackinnon, M.J. et al. Comparative transcriptional and genomic analysis of Plasmodium falciparum field isolates. PLoS Pathog 5, e1000644 (2009), 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 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: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. 11 P. falciparum parasites (field isolates) which are either Artemsinin resistant or sensitive from 3 study sites (Pailin in Cambodia, Xepon in Laos, Mae Sot in Thailand) were sampled, grown ex-vivo over 48 hours and harvested at regular intervals. RNA from a total of 91 samples were extracted. Synthesis of target DNA was carried out as previously described: Mackinnon, M.J. et al. Comparative transcriptional and genomic analysis of Plasmodium falciparum field isolates. PLoS Pathog 5, e1000644 (2009), and used in microarray hybridizations.
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.
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.
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.
Project description:RNAseq data profiling the artemisinin-sensitive P. falciparum piggyBac mutant of the PF3D7_1136600 gene (conserved Plasmodium gene, unknown function)