Multiple levels of gene regulation mediate differentiation of the intracellular pathogen Leishmania
Ontology highlight
ABSTRACT:
ORGANISM(S): Leishmania donovani Leishmania infantum JPCM5
PROVIDER: GSE21936 | GEO | 2010/08/15
SECONDARY ACCESSION(S): PRJNA126877
REPOSITORIES: GEO
Similar Datasets
Project description:Whole genome high density tiliing array of eight timepoints from the promastitgote to amastigote differentiation process. RNA from two independent biological replicates from eight points in the promastigote to amastigote differentiation process were hybridized to Nimblegen arrays (Madison,WI USA) that contained 10 probes per open reading frame and 3 probes per structural RNA spotted three times per array. The microarray probes were designed to Leishmania infantum strain JCPM5 and the sample RNA was obtained from Leishmania donovani strain S1. The two species are thought to be nearly identical at the nucleotide level, however whole-genome sequence was not available from L. donovani.
2010-08-15 | E-GEOD-21936 | biostudies-arrayexpress
Project description:For many years, mRNA abundance has been used as the surrogate measure of gene expression in biological systems. However, recent genome-scale analyses in both bacteria and eukaryotes have revealed that mRNA levels correlate with steady-state protein abundance for only 50-70% of genes, indicating that translation and post-translation processes also play important roles in determining gene expression. What is not yet clear is whether dynamic processes such as cell cycle progression, differentiation, or response to environmental changes change the relationship between mRNA and protein abundance. Here, we describe a systems approach to interrogate promastigote-to-amastigote differentiation in the obligatory intracellular parasitic protozoan Leishmania donovani. Our results indicate that regulation of mRNA levels plays a major role early in the differentiation process, while translation and post-translational regulation are more important in the latter part. In addition, it appears that the differentiation signal causes a transient global increase in the rate of protein synthesis, which is subsequently down-regulated by phosphorylation of ?-subunit of translation initiation factor 2. Thus, Leishmania dynamically changes the relationship between mRNA and protein abundance as it adapts to new environmental circumstances. It is likely that similar mechanisms play a more important role than previously recognized in regulation of gene expression in other organisms.
| S-EPMC6188352 | biostudies-literature
Project description:Transcriptional analysis of L. infantum promastigote compared to L. infantum intracellular amastigote and transcriptional analysis of L. infantum promastigote compared to L. infantum axenic amastigote. The full-genome DNA microarrays includes one 70-oligonucleotides probe for each gene of L.infantum. Keywords: stage and culture condition
2009-01-08 | GSE13983 | GEO
Project description:Transcriptional analysis of L. infantum promastigote compared to L. infantum intracellular amastigote and transcriptional analysis of L. infantum promastigote compared to L. infantum axenic amastigote. The full-genome DNA microarrays includes one 70-oligonucleotides probe for each gene of L.infantum. Keywords: stage and culture condition Intracellular amastigote analysis: Two-condition experiment, promastigote stage vs intracellular amastigote stage. Six biological replicates for each stage, independently grown and harvested. One replicate per array Axenic amastigote analysis: Two-condition experiment, promastigote stage vs axenic amastigote stage. Four biological replicates for each stage, independently grown and harvested. One replicate per array.
2010-05-14 | E-GEOD-13983 | biostudies-arrayexpress
Project description:We examined the Leishmania mexicana transcriptome to identify differentially regulated mRNAs using high-density whole-genome oligonucleotide microarrays designed from the genome data of a closely related species, Leishmania major. Statistical analysis on array hybridization data representing 8156 predicted coding regions revealed 288 genes (3.5% of all genes) whose steady-state mRNA levels meet criteria for differential regulation between promastigotes and lesion-derived amastigotes. Interestingly, sample comparison of promastigotes to axenic amastigotes resulted in only 17 genes (0.2%) that meet the same statistical criteria for differential regulation. The reduced number of regulated genes is a consequence of an increase in the magnitude of the transcript levels in cells under axenic conditions. The expression data for a subset of genes was validated by quantitative PCR. Our studies show that interspecies hybridization on microarrays can be used to analyze closely related protozoan parasites, that axenic culture conditions may alter amastigote transcript abundance, and that there is only a relatively modest change in abundance of a few mRNAs between morphologically distinct promastigote and amastigote cultured cells. Leishmania may represent an alternative paradigm for eukaryotic differentiation with minimal contributions from changes in mRNA abundance. Keywords: RNA expression profiling
2006-03-10 | GSE4431 | GEO
Project description:Transcriptional analyses of L. infantum promastigote compared to L. infantum intracellular amastigote, and L. major promastigote compared to L. major intracellular amastigote The full-genome DNA microarray includes one 70mer-oligonucleotide probe for each gene of L. infantum and for each gene of L.major LV39 Keywords: stage-specific comparison
2008-05-28 | GSE10407 | GEO
Project description:Transcriptional analyses of L. infantum promastigote compared to L. infantum intracellular amastigote, and L. major promastigote compared to L. major intracellular amastigote The full-genome DNA microarray includes one 70mer-oligonucleotide probe for each gene of L. infantum and for each gene of L.major LV39 Keywords: stage-specific comparison Leishmania infantum: Two-condition experiment, promastigote stage vs amastigote stage. Six biological replicates for each stage, independently grown and harvested. One replicate per array Leishmania major: Two-condition experiment, promastigote stage vs amastigote stage. Four biological replicates for each stage, independently grown and harvested. One replicate per array
2008-05-28 | E-GEOD-10407 | biostudies-arrayexpress
Project description:Whole-genome comparative RNA expression profiling of axenic and intracellular amastigote forms of Leishmania infantum
| PRJNA110243 | ENA
Project description:During its life cycle Leishmania undergoes extreme environmental changes, alternating between insect vectors and vertebrate hosts. In mammals the parasites replicate within parasitophorous vacuoles of macrophages, compartments that contain low concentrations of iron. Here we show that stimulation of iron transport, which is induced in Leishmania amazonensis by an iron-poor environment, triggers the differentiation of avirulent promastigotes into virulent amastigotes. Iron depletion from the culture medium triggered expression of the LIT1 ferrous iron transporter, growth arrest, and differentiation of wild type promastigotes into infective amastigotes. In contrast, LIT1 null promastigotes showed continued exponential growth in iron-poor media, followed by massive cell death. Iron depletion from the medium and LIT1 upregulation increased iron superoxide dismutase activity (FeSOD) in wild type, but not in LIT1 null parasites. Notably, the superoxide-generating drug menadione or H2O2 were sufficient to trigger differentiation of wild type promastigotes into fully infective amastigotes. On the other hand, LIT1 null promastigotes accumulated superoxide radical and initiated amastigote differentiation after exposure to H2O2, but not to menadione. Our results reveal a novel role for FeSOD activity and reactive oxygen species (ROS) in orchestrating the differentiation of Leishmania infective stages, in a process regulated by iron availability.
2012-12-15 | GSE41641 | GEO
Project description:Visceral leishmaniasis (VL) is associated with treatment complications due to the continued growth of resistant parasites toward currently available pathogen-directed therapeutics. To limit the emergence and combat resistant parasites there is a need to develop new anti-leishmanial drugs and alternative treatment approaches, such as host-directed therapeutics (HDTs). Discovery of new anti-leishmanial drugs including HDTs requires suitable in vitro assay systems. Herein, we modified and evaluated a series of resazurin assays against different life-stages of the VL causing parasite, Leishmania donovani to identify novel HDTs. We further analyzed the synergy of combinatorial interactions between traditionally used pathogen-directed drugs and HDTs for clearance of intracellular L. donovani. The inhibitory concentration at 50% (IC50) of the five evaluated therapies [amphotericin B (AMB), miltefosine, paromomycin, DNER-4, and AR-12 (OSU-03012)] was determined against promastigotes, extracellular amastigotes, and intracellular amastigotes of L. donovani via a resazurin-based assay and compared to image-based microscopy. Using the resazurin-based assay, all evaluated therapies showed reproducible anti-leishmanial activity against the parasite's different life-stages. These results were consistent to the traditional image-based technique. The gold standard of therapy, AMB, showed the highest potency against intracellular L. donovani, and was further evaluated for combinatorial effects with the HDTs. Among the combinations analyzed, pathogen-directed AMB and host-directed AR-12 showed a synergistic reduction of intracellular L. donovani compared to individual treatments. The modified resazurin assay used in this study demonstrated a useful technique to measure new anti-leishmanial drugs against both intracellular and extracellular parasites. The synergistic interactions between pathogen-directed AMB and host-directed AR-12 showed a great promise to combat VL, with the potential to reduce the emergence of drug-resistant strains.
| S-EPMC6731340 | biostudies-literature