Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for the transcriptional response of control Plasmodium falciparum asexual blood stages not treated with the calcium ionophores, A23187 and ionomycin has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the untreated parasites were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for extracellular calcium chelation of the control Plasmodium falciparum asexual blood stages not treated with the calcium ionophore ionomycin and EGTA has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the untreated parasites were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for the transcriptional response of Plasmodium falciparum asexual blood stages to the well-known calcium ionophore A23187 has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Calcium ionophore treatment was done as follows. Parasites at schizont stage were treated with 5 μM of calcium ionophore, A23187 for 30 minutes, 1 hour, 2 hours, 4 hours and 6 hours. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the treated parasites were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for the transcriptional response of Plasmodium falciparum asexual blood stages to the well-known calcium ionophore ionomycin has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Calcium ionophore treatment was done as follows. Parasites at schizont stage were treated with 5 μM of calcium ionophore, ionomycin for 30 minutes, 1 hour, 2 hours, 4 hours and 6 hours. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the treated parasites were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for extracellular calcium chelation of the control Plasmodium falciparum asexual blood stages treated with the calcium ionophore ionomycin has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the parasites treated with 5 μM ionomycin were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for extracellular calcium chelation of the control Plasmodium falciparum asexual blood stages treated with the calcium ionophore EGTA ans later with ionomycin has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the parasites treated with 3 mM of EGTA and later with 5 μM ionomycin were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
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.
Project description:Abstract of associated publication: Background: During the latter half of the natural 48-hour intraerythrocytic life cycle of human Plasmodium falciparum infection, parasites sequester deep in endothelium tissues, away from the spleen and inaccessible to peripheral blood. These late-stage parasites may cause tissue damage and likely contribute to clinical disease, and a more complete understanding of their biology is needed. Because these life cycle stages are not easily sampled due to deep tissue sequestration, measuring in vivo gene expression of parasites in the trophozoite and schizont stages has been a challenge. Methods: We developed a custom nCounter® gene expression platform, and used this platform to measure malaria parasite gene expression profiles in vitro and in vivo. We also used imputation to generate global transcriptional profiles, and assessed differential gene expression between parasites growing in vitro and those recovered from malaria-infected patient tissues collected at autopsy. Results: We demonstrate, for the first time, global transcriptional expression profiles from in vivo malaria parasites sequestered in human tissues. We found that parasite physiology can be correlated with in vitro data from an existing life cycle data set, and that parasites in sequestered tissues show an expected schizont-like transcriptional profile, which is conserved across tissues from the same patient. Imputation based on 60 landmark genes generated global transcriptional profiles that were highly correlated with genome-wide expression patterns from the same sample measured by microarray. Finally, differential expression revealed a limited set of in vivo upregulated transcripts, which may indicate unique parasite genes involved in human clinical infections. Conclusions: Our study highlights the utility of a custom nCounter® P. falciparum probe set, validation of imputation within Plasmodium species, and documentation of in vivo schizont-stage expression patterns from human tissues.