Pyocyanin has been shown to engage in redox transfer of electrons from NADPH to oxygen to generate superoxide radicals. Transcriptional response to oxygen stress has been characterized in yeast and should be observable upon exposure to pyocyanin if this is the true mode of action.
Pyocyanin isolated from a marine microbial population: synergistic production between two distinct bacterial species and mode of action.
No sample metadata fields
View SamplesThe generation of induced pluripotent stem cells (iPSCs) and the direct conversion approach provide an invaluable resource of cells for disease modeling, drug screening, and patient-specific cell-based therapy. However, while iPSCs are stable and resemble ESCs in their transcriptome, methylome and function, the vast majority of the directly converted cells represent an incomplete reprogramming state as evident by their aberrant transcriptome and transgene dependency. This raises the question of whether complete and stable nuclear reprogramming can be achieved only in pluripotent cells. Here we demonstrate the generation of stable and fully functional induced trophoblast stem cells (iTSCs) by transient expression of Gata3, Tfap2c and Eomes. Similarly to iPSCs, iTSCs underwent a complete and stable reprogramming process as assessed by transcriptome and methylome analyses and functional assays such as the formation of hemorrhagic lesion and placenta contribution. Careful examination of the conversion process indicated that the cells did not go through a transient pluripotent state. These results suggest that complete nuclear reprograming can be attained in non-pluripotent cells. Overall design: Technical duplicates of 10 samples
Extensive Nuclear Reprogramming Underlies Lineage Conversion into Functional Trophoblast Stem-like Cells.
No sample metadata fields
View SamplesThe highly conserved Wnt signaling pathway drives intestinal homeostasis across species. Apc is a negative regulator of Wnt signaling. Loss of function mutations in Apc are found in 80-90% of human colorectal cancers. Importantly, Apc loss is widely known as the key driving event in the disease.
Intestinal stem cell overproliferation resulting from inactivation of the APC tumor suppressor requires the transcription cofactors Earthbound and Erect wing.
Sex, Age, Specimen part
View SamplesThe tumorigenicity of human pluripotent stem cells (hPSCs) is a major safety concern for their application in regenerative medicine. Here we identify the tight-junction protein Claudin-6 as a specific cell surface marker of hPSCs that can be used to selectively remove Claudin-6-positive cells from mixed cultures. We show that Claudin-6 is absent in adult tissues but highly expressed in undifferentiated cells, where it is dispensable for hPSC survival and self-renewal. We use three different strategies to remove Claudin-6-positive cells from mixed populations: an antibody against Claudin-6; a cytotoxin-conjugated antibody that selectively targets undifferentiated cells; and clostridium perfringens enterotoxin, a toxin that binds several Claudins, including Claudin-6, and efficiently kills undifferentiated cells, thus eliminating the tumorigenic potential of hPSC-containing cultures. This work provides a proof of concept for the use of Claudin-6 to eliminate residual undifferentiated hPSCs from culture, highlighting a strategy that may increase the safety of hPSC-based cell therapies.
Immunologic and chemical targeting of the tight-junction protein Claudin-6 eliminates tumorigenic human pluripotent stem cells.
Specimen part, Cell line
View SamplesPluripotent-specific inhibitors (PluriSIns) make a powerful tool for studying the mechanisms that control the survival of human pluripotent stem cells (hPSCs). Here we characterize PluriSIn#2 as a novel selective indirect inhibitor of topoisomerase II alpha (TOP2A). We find that TOP2A is uniquely expressed in undifferentiated hPSCs, and that its inhibition results in their rapid cell death. These findings reveal a dependency of hPSCs on the activity of TOP2A, which can be harnessed for their selective elimination from culture.
Brief reports: Controlling the survival of human pluripotent stem cells by small molecule-based targeting of topoisomerase II alpha.
Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Toxicogenomics of iron oxide nanoparticles in the nematode C. elegans.
Specimen part
View SamplesSuperparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. We have investigated the molecular mechanisms responsive to in-house fabricated citrate coated SPIONs (C-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. C-SPIONs (500 g/ml) affected the transcriptional response of signal transduction cascades (i.e. TFG-beta), protein processing in the endoplasmic reticulum, and RNA transport, among other biological processes. They also triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Interestingly, other pathways frequently linked to nanotoxicity like oxidative stress or apoptosis were not identified as significantly affected in this genome-wide in vivo study despite the high dose of exposure.
Toxicogenomics of iron oxide nanoparticles in the nematode C. elegans.
Specimen part
View SamplesSuperparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. Different NP coatings are being explored, among them albumin which has been applied in some drugs delivery systems. We have investigated the molecular mechanisms responsive to in-house fabricated SPIONs coated with bovine serum albumin (BSA-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. BSA-SPIONs (500 g/ml) affected the transcriptional response of glycan metabolic pathways related to innate immune response, xenobiotics degradation, and triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Remarkably, key biological functions such as apoptosis or protein processing were not affected with significance despite the high dose of exposure.
Toxicogenomics of iron oxide nanoparticles in the nematode C. elegans.
Specimen part
View SamplesPostweaning multisystemic wasting syndrome (PMWS) is one of the pig diseases with major economic impact worldwide. Clinical, pathologic and some immunologic aspects of this disease are well-known, but the molecular mechanisms underlying pathogenic mechanisms of the disease are still poorly understood. The objective of the present study was to investigate the global changes in gene expression in the mediastinal lymph nodes from pigs naturally affected by PMWS and healthy counterparts, using the Affymetrix Porcine Genechip. This is the first study on gene expression in pigs naturally affected by PMWS. The present results allowed identifying potential mechanisms underlying the inflammation, lymphocyte depletion in lymphoid tissues and immune suppression, which are key features of PMWS.
Microarray analysis of mediastinal lymph node of pigs naturally affected by postweaning multisystemic wasting syndrome.
Age, Specimen part, Disease, Disease stage
View SamplesGene expression was compared for wild type yeast (BY4741) and yeast lacking Gal11/Med15 and Med3, or from a gal11-myc med3 strain. The gal11-myc allele shows a partial loss of function when combined with med3. Expression was analyzed for yeast grown in YPD as well as in CSM.
Distinct role of Mediator tail module in regulation of SAGA-dependent, TATA-containing genes in yeast.
No sample metadata fields
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