Natural anitsense transcripts in Plasmodium falciparum clinical isolates
Ontology highlight
ABSTRACT:
ORGANISM(S): Plasmodium falciparum 3D7 Plasmodium falciparum
PROVIDER: GSE44921 | GEO | 2014/04/30
SECONDARY ACCESSION(S): PRJNA192674
REPOSITORIES: GEO
Similar Datasets
Project description:Mechanisms regulating gene expression in malaria parasites are not well understood. Little is known about how this parasite regulates its gene expression during transition from one developmental stage to another and in response to various environmental conditions. Parasites in a diseased host face environments which differ from the static, well adapted in vitro conditions in culture. Parasites thus need to adapt quickly and effectively to these conditions by establishing transcriptional states which is best suited for better survival. With the discovery of natural antisense transcripts (NATs) in this parasite and considering the various proposed mechanisms by which NATs might regulate gene expression, it has been speculated that these might be playing a critical role in gene regulation. We report here the diversity of NATs that exist in this parasite, using isolates taken directly from patients with differing clinical symptoms caused by malaria infection. A total of 797 NATs targeted against annotated loci have been detected using a custom designed strand specific microarray. Out of these, 545 are unique to this study. The majority of NATs were positively correlated with the expression pattern of the sense transcript. Many were found to be differentially regulated in response to disease conditions. Antisense transcripts mapped to a wide variety of biochemical/ metabolic pathways, especially pathways pertaining to the central carbon metabolism and stress related pathways. Our data strongly suggests that a large group of NATs detected here are unannotated transcription units antisense to annotated gene models. The results reveal a previously unknown set of NATs that prevails in this parasite, their differential regulation in disease conditions and mapping to functionally well annotated genes. The results detailed here call for studies to deduce the possible mechanism of action, which would help in understanding the in vivo pathological adaptations of these parasites. Plasmodium falciparum isolates were collected from patients (n = 11) with differing clinical conditions.The patients exhibited symptoms categorized as un-complicated (n =2) or complicated malaria (n = 9). Criteria for determination of complicated disease were based on World Health Organization year 2000 guidelines. Microarray array based transcriptional profiling was carried out to detect prevalence of natural antisense transcript.
2014-04-30 | E-GEOD-44921 | biostudies-arrayexpress
Project description:Plasmodium vivax is the most geographically widespread human malaria parasite causing approximately 130-435 million infections annually. It is an economic burden in many parts of the world and poses a public health challenge along with the other Plasmodium sp. The biology of this parasite is very little understood. Emerging evidences of severe complications due to infections by this parasite provides an impetus to focus research on the same. Investigating this parasite directly from the infected patients is the most feasible way to study its biology and any pathogenic mechanisms which may exist. Gene expression studies of this parasite directly obtained from the patients has provided evidence of gene regulation resulting in varying amount of transcript levels in the different blood stages. However, the mechanisms regulating gene expression in malaria parasites are not well understood. Discovery of natural antisense transcripts (NATs) in P. falciparum has suggested that these might play an important role in regulating gene expression. We report here the genome-wide occurrence of NATs in P. vivax parasites from patients with differing clinical symptoms. A total of 1348 NATs against annotated gene loci have been detected using a custom designed strand specific microarray. Majority of NATs identified from this study shows positive correlation with the expression pattern of the sense transcript. Our data also shows condition specific expression patterns of varying S and AS transcript levels. Genes with AS transcripts enrich to various biological processes. This is the first report detailing the presence of NATs from clinical isolates of P. vivax. The data suggests differential regulation of gene expression in diverse clinical conditions and would lead to future detailed investigations of genome regulation. Plasmodium vivax isolates were collected from patients (n = 8) with differing clinical conditions.The patients exhibited symptoms categorized as un-complicated (n =1) or complicated malaria (n = 7). Criteria for determination of complicated disease were based on World Health Organization year 2010 guidelines. Microarray array based transcriptional profiling was carried out to detect prevalence of natural antisense transcripts.
2014-01-16 | E-GEOD-45165 | biostudies-arrayexpress
Project description:Plasmodium vivax is the most geographically widespread human malaria parasite causing approximately 130-435 million infections annually. It is an economic burden in many parts of the world and poses a public health challenge along with the other Plasmodium sp. The biology of this parasite is very little understood. Emerging evidences of severe complications due to infections by this parasite provides an impetus to focus research on the same. Investigating this parasite directly from the infected patients is the most feasible way to study its biology and any pathogenic mechanisms which may exist. Gene expression studies of this parasite directly obtained from the patients has provided evidence of gene regulation resulting in varying amount of transcript levels in the different blood stages. However, the mechanisms regulating gene expression in malaria parasites are not well understood. Discovery of natural antisense transcripts (NATs) in P. falciparum has suggested that these might play an important role in regulating gene expression. We report here the genome-wide occurrence of NATs in P. vivax parasites from patients with differing clinical symptoms. A total of 1348 NATs against annotated gene loci have been detected using a custom designed strand specific microarray. Majority of NATs identified from this study shows positive correlation with the expression pattern of the sense transcript. Our data also shows condition specific expression patterns of varying S and AS transcript levels. Genes with AS transcripts enrich to various biological processes. This is the first report detailing the presence of NATs from clinical isolates of P. vivax. The data suggests differential regulation of gene expression in diverse clinical conditions and would lead to future detailed investigations of genome regulation.
2014-01-16 | GSE45165 | GEO
Project description:<p>High throughput RNA Sequencing has revealed that the human genome is widely transcribed. However, the extent of natural antisense transcription, the molecular mechanisms by which natural antisense transcripts (NATs) might affect their cognate sense genes, and the role of NATs in cancer are less well understood. Here, we use strand-specific paired-end RNA sequencing (ssRNASeq) on a cohort of 376 cancer patients covering 9 tissue types to comprehensively characterize the landscape of antisense expression. Our results reveal that greater than 60% of annotated transcripts have measureable antisense expression and the expression of sense and antisense transcript pairs is in general positively correlated. Furthermore, by studying the expression of sense/antisense pairs across tissues we identify lineage-specific, ubiquitous and cancer-specific antisense loci. Our results raise the possibility that NATs participate in the regulation of well-known tumor suppressors and oncogenes. Finally, this study provides a catalogue of cancer related genes with significant antisense transcription (oncoNAT). This resource will allow researchers to investigate the molecular mechanisms of sense/antisense regulation and further advance our understanding of their role in cancer.</p>
| phs000937 | dbGaP
Project description:High throughput RNA sequencing has revealed pervasive transcription of human genome than previously anticipated. However, the extent of natural antisense transcripts (NATs) expression, their regulation of cognate sense genes, and the role of NATs in cancer remain poorly understood. Here, we use strand-specific paired-end RNA sequencing (ssRNASeq) data from 376 cancer patients covering 9 tissue types to comprehensively characterize the landscape of antisense expression. We found consistent antisense expression in at least 38% of annotated transcripts, which in general is positively correlated with sense gene expression. Investigations of sense/antisense pair expression across tissue types revealed lineage-specific, ubiquitous and cancer-specific antisense loci transcription. Comparisons between tumor and normal samples identified both concordant (same direction) and discordant (opposite direction) sense/antisense expression patterns. Finally, we provide oncoNAT, a catalog of cancer related genes with significant antisense transcription, which will enable future investigations of sense/antisense regulation in cancer. Using oncoNAT we identified several functional NATs, including NKX2-1-AS that regulates the NKX2-1 oncogene and cell proliferation in lung cancer cells. Overall, this study provides a comprehensive account of NATs and supports a role for NATs regulation of tumor suppressors and oncogenes in cancer biology.
2015-05-28 | GSE66727 | GEO
Project description:High throughput RNA sequencing has revealed pervasive transcription of human genome than previously anticipated. However, the extent of natural antisense transcripts (NATs) expression, their regulation of cognate sense genes, and the role of NATs in cancer remain poorly understood. Here, we use strand-specific paired-end RNA sequencing (ssRNASeq) data from 376 cancer patients covering 9 tissue types to comprehensively characterize the landscape of antisense expression. We found consistent antisense expression in at least 38% of annotated transcripts, which in general is positively correlated with sense gene expression. Investigations of sense/antisense pair expression across tissue types revealed lineage-specific, ubiquitous and cancer-specific antisense loci transcription. Comparisons between tumor and normal samples identified both concordant (same direction) and discordant (opposite direction) sense/antisense expression patterns. Finally, we provide oncoNAT, a catalog of cancer related genes with significant antisense transcription, which will enable future investigations of sense/antisense regulation in cancer. Using oncoNAT we identified several functional NATs, including NKX2-1-AS that regulates the NKX2-1 oncogene and cell proliferation in lung cancer cells. Overall, this study provides a comprehensive account of NATs and supports a role for NATs regulation of tumor suppressors and oncogenes in cancer biology.
2015-05-28 | GSE66728 | GEO
Project description:High throughput RNA sequencing has revealed pervasive transcription of human genome than previously anticipated. However, the extent of natural antisense transcripts (NATs) expression, their regulation of cognate sense genes, and the role of NATs in cancer remain poorly understood. Here, we use strand-specific paired-end RNA sequencing (ssRNASeq) data from 376 cancer patients covering 9 tissue types to comprehensively characterize the landscape of antisense expression. We found consistent antisense expression in at least 38% of annotated transcripts, which in general is positively correlated with sense gene expression. Investigations of sense/antisense pair expression across tissue types revealed lineage-specific, ubiquitous and cancer-specific antisense loci transcription. Comparisons between tumor and normal samples identified both concordant (same direction) and discordant (opposite direction) sense/antisense expression patterns. Finally, we provide oncoNAT, a catalog of cancer related genes with significant antisense transcription, which will enable future investigations of sense/antisense regulation in cancer. Using oncoNAT we identified several functional NATs, including NKX2-1-AS that regulates the NKX2-1 oncogene and cell proliferation in lung cancer cells. Overall, this study provides a comprehensive account of NATs and supports a role for NATs regulation of tumor suppressors and oncogenes in cancer biology. Strand-specific RNA sequencing data (ssRNASeq) of cancer and benign samples. SRP048484 (PRJNA262128).
2015-05-28 | E-GEOD-66727 | biostudies-arrayexpress
Project description:High throughput RNA sequencing has revealed pervasive transcription of human genome than previously anticipated. However, the extent of natural antisense transcripts (NATs) expression, their regulation of cognate sense genes, and the role of NATs in cancer remain poorly understood. Here, we use strand-specific paired-end RNA sequencing (ssRNASeq) data from 376 cancer patients covering 9 tissue types to comprehensively characterize the landscape of antisense expression. We found consistent antisense expression in at least 38% of annotated transcripts, which in general is positively correlated with sense gene expression. Investigations of sense/antisense pair expression across tissue types revealed lineage-specific, ubiquitous and cancer-specific antisense loci transcription. Comparisons between tumor and normal samples identified both concordant (same direction) and discordant (opposite direction) sense/antisense expression patterns. Finally, we provide oncoNAT, a catalog of cancer related genes with significant antisense transcription, which will enable future investigations of sense/antisense regulation in cancer. Using oncoNAT we identified several functional NATs, including NKX2-1-AS that regulates the NKX2-1 oncogene and cell proliferation in lung cancer cells. Overall, this study provides a comprehensive account of NATs and supports a role for NATs regulation of tumor suppressors and oncogenes in cancer biology. Strand-specific RNA sequencing data (ssRNASeq) of cancer and benign samples. SRP050021 (PRJNA267614). Processed data files linked to SuperSeries record.
2015-05-28 | E-GEOD-66728 | biostudies-arrayexpress
Project description:Cumulative malaria parasite exposure in endemic regions often results in the acquisition of partial immunity and asymptomatic infections. There is limited information on how host-parasite interactions mediate maintenance of chronic symptomless infections that sustain malaria transmission. Here, we have determined the gene expression profiles of the parasite population and the corresponding host peripheral blood mononuclear cells (PBMCs) from 21 children (<15 years). We compared children who were defined as uninfected, asymptomatic and those with febrile malaria. Children with asymptomatic infections had a parasite transcriptional profile characterized by a bias toward trophozoite stage (~12 hours-post invasion) parasites and low parasite levels, while earlier ring stage parasites were characteristic of febrile malaria. The host response of asymptomatic children was characterized by downregulated transcription of genes associated with inflammatory responses, compared with children with febrile malaria, which may lead to less cytoadherence of more mature parasite stages. Interestingly, the host responses during febrile infections that followed an asymptomatic infection featured stronger inflammatory responses, whereas the febrile host responses from previously uninfected children featured increased humoral immune responses. The priming effect of prior asymptomatic infection may explain the blunted acquisition of antibody responses seen to malaria antigens following natural exposure or vaccination in malaria endemic areas.
2024-02-14 | GSE240643 | GEO
Project description:The human malaria parasite Plasmodium falciparum has a complex and multi-stage life cycle that requires extensive immune escape, invasion of human liver and blood cells, and transmission through the female Anopholes mosquito. To date, the regulatory elements orchestrating these critical parasite processes remain largely unknown. However, there is mounting evidence across a broad range of species that intergenic long non-coding RNA (lncRNA) and antisense RNA can regulate chromatin state and gene expression. To pursue such functional roles for lncRNAs in P. falciparum, we performed deep, strand-specific RNA sequencing of fifteen non-polyA-selected blood stage samples, and assembled and characterized the properties of 660 intergenic lncRNAs, 474 antisense RNAs, and 1381 circular RNAs (circRNAs). We further validated the non-canonical splice junctions of seven P. falciparum circRNAs, an emerging class of non-coding RNA with regulatory potential and unexplored functional significance in P. falciparum. Our comprehensive analysis of P. falciparum lncRNAs indicates a functional role for these transcripts; P. falciparum intergenic lncRNAs and antisense RNAs are developmentally regulated in a similar periodic fashion to annotated transcripts, and sense-antisense pair expression is significantly anti-correlated. Notable outliers include intergenic lncRNAs that strongly peak in expression during parasite invasion, such as the telomere-associated lncRNA-TARE family, antisense transcripts that drop in expression during parasite invasion, and a highly correlated, multi-exonic, antisense counterpart to P. falciparum Gametocyte Developmental Protein 1 (PfGDV1). Taken together, our results present over two thousand P. falciparum intergenic lncRNA, antisense, and circRNA candidates and highlight promising P. falciparum lncRNAs for future investigation. We harvested fifteen blood stage samples from two biological replicate time-courses. The first time-course comprised of eleven samples that finely map temporal changes during P. falciparum blood stage development. We harvested samples over 56 hours, at roughly 4-hour time intervals, from a tightly synchronized P. falciparum 3D7 parasite population. As the asexual blood stage is an approximately 48-hour cycle, this time-course allowed us to profile gene expression during RBC rupture and parasite invasion. The second time-course comprised of four samples harvested in synchronous P. falciparum 3D7 parasites approximately four hours before and after the ring to trophozoite and trophozoite to schizont morphological stage transitions, which occur during the blood stage at 24 hours post invasion (hpi) and 36 hpi, respectively.
2015-05-08 | E-GEOD-57439 | biostudies-arrayexpress