Background: Constant hypoxia (CH) and intermittent hypoxia (IH) occur during several pathological conditions such as asthma and obstructive sleep apnea. Our research is focused on understanding the molecular mechanisms that lead to injury or adaptation to hypoxic stress using Drosophila as a model system. Our current genome-wide study is designed to investigate gene expression changes and identify protective mechanism(s) in D. melanogaster after exposure to severe (1% O2) intermittent or constant hypoxia.
Distinct mechanisms underlying tolerance to intermittent and constant hypoxia in Drosophila melanogaster.
Specimen part
View SamplesDuring the past two decades although many genes e.g.,Gdf5, Wnt9a, Noggin etc. have been identified and characterized in joint development, still a comprehensive understanding of molecular network operational in articular cartilage morphogenesis is far from being drawn. This might be due to incompleteness in the number of molecules identified.
A comprehensive mRNA expression analysis of developing chicken articular cartilage.
Specimen part
View SamplesHypoxia plays a key pathogenic role in the outcome of many pathologic conditions. To elucidate how organisms successfully adapt to hypoxia, a population of Drosophila melanogaster was generated, through an iterative selection process, that is able to complete its lifecycle at 4% O2, a level lethal to the starting parental population. Transcriptomic analysis of flies adapted for >200 generations was performed to identify pathways and processes that contribute to the adapted phenotype, comparing gene expression of three developmental stages with generation-matched control flies. A third group was included, hypoxia-adapted flies reverted to 21% O2 for five generations, to address the relative contributions of genetics and hypoxic environment to the gene expression differences. We identified the largest number of expression differences in 0.5-3 hr post-eclosion adult flies that were hypoxia-adapted and maintained in 4% O2, and found evidence that changes in Wnt signaling contribute to hypoxia tolerance in flies.
Wnt pathway activation increases hypoxia tolerance during development.
No sample metadata fields
View SamplesIn Saccharomyces cerevisiae, Sen1 is a 252-kDa, nuclear superfamily-1 RNA/DNA helicase that encoded by an essential gene SEN1 (Senataxin). It is an important component of the Nrd1p-Nab3p-Sen1p (NRD1) complex that regulates the transcriptional termination of most non-coding and some coding transcripts at RNA polymerase pause sites. Sen1 specifically interacts with Rnt1p (RNase III), an endoribonuclease, and with Rpb1p (Rpo21p), a subunit of RNA polymerase II, through its N-terminal domain (NTD), which is a critical element of the RNA-processing machinery. Moreover, mutations in the N-terminal tail of SETX, a human ortholog of yeast Senataxin (Sen1) reported in neurological disorders.
Sen1, the homolog of human Senataxin, is critical for cell survival through regulation of redox homeostasis, mitochondrial function, and the TOR pathway in Saccharomyces cerevisiae.
No sample metadata fields
View Sampleswe investigated the effect of HFD on the transcriptome in the heads and bodies of male and female flies kept on either HFD or regular diet (RD). Using comprehensive genomic analyses which include high-throughput transcriptome sequencing, pathway enrichment and gene network analyses, we found that HFD induces a number of responses that are sexually dimorphic in nature. There was a robust transcriptional response consisting of a downregulation of stress-related genes in the heads and glycoside hydrolase activity genes in the bodies of males. In the females, the HFD led to an increased transcriptional change in lipid metabolism. Overall design: Examination of head and body of male and female Drosophila kept on High fat and regular diet.
High fat diet induces sex-specific differential gene expression in Drosophila melanogaster.
Sex, Specimen part, Cell line, Subject
View SamplesRNA-Seq analysis was performed to assess how a glucose-supplemented diet and/or a hyl-2 mutation altered the transcriptome. Comparison analysis of transcripts associated with anoxia sensitive animals (hyl-2(tm2331) mutation or a glucose diet) revealed 199 common transcripts encoded by genes with known or predicted functions involving innate immunity, cuticle function (collagens) or xenobiotic and endobiotic phase I and II detoxification system. Overall design: mRNA profiles of OP50-fed C. elegans, glucose-fed C. elegans (N2 strain), OP50-fed C. elegans altered in ceramide metabolism (due to a hyl-2(tm2031) mutation), and glucose-fed C. elegans altered in ceramide metabolism were generated by RNA-Seq, in triplicate, using an Illumina HiSeq2000. Transcriptome data were then used for a comprehensive quantitative analysis of differential gene regulation in hyl-2(tm2031) and glucose-fed C. elegans.
Glucose or Altered Ceramide Biosynthesis Mediate Oxygen Deprivation Sensitivity Through Novel Pathways Revealed by Transcriptome Analysis in Caenorhabditis elegans.
Cell line, Subject
View SamplesHuman alveolar macrophages (HAM) are primary bacterial niche and immune response cells during Mycobacterium tuberculosis (M.tb) infection, and human blood monocyte-derived macrophages (MDM) are a model for investigating M.tb-macrophage interactions. Here, we use a targeted RNA-Seq method to measure transcriptome-wide changes in RNA expression patterns of freshly obtained HAM (used within 6 h) and 6 day cultured MDM upon M.tb infection over time (2, 24 and 72 h), in both uninfected and infected cells from three donors each. The Ion AmpliSeqâ„¢ Transcriptome Human Gene Expression Kit (AmpliSeq) uses primers targeting 18,574 mRNAs and 2,228 non-coding RNAs (ncRNAs) for a total of 20,802 transcripts. AmpliSeqTM yields highly precise and reproducible gene expression profiles (R2 >0.99). Taking advantage of AmpliSeq's reproducibility, we establish well-defined quantitative RNA expression patterns of HAM versus MDM, including significant M.tb-inducible genes, in networks and pathways that differ in part between MDM and HAM. A similar number of expressed genes are detected at all time-points between uninfected MDM and HAM, in common pathways including inflammatory and immune functions, but canonical pathway differences also exist. In particular, at 2 h, multiple genes relevant to the immune response are preferentially expressed in either uninfected HAM or MDM, while the HAM RNA profiles approximate MDM profiles over time in culture, highlighting the unique RNA expression profile of freshly obtained HAM. MDM demonstrate a greater transcriptional response than HAM upon M.tb infection, with 2 to >10 times more genes up- or down-regulated. The results identify key genes involved in cellular responses to M.tb in two different human macrophage types. Follow-up bioinformatics analysis indicates that approximately 30% of response genes have expression quantitative trait loci (eQTLs in GTEx), common DNA variants that can influence host gene expression susceptibility or resistance to M.tb, illustrated with the TREM1 gene cluster and IL-10. Overall design: Assessment of transcriptome profiles from cells infected with Mycobacterium tuberculosis using AmpliSeq.
AmpliSeq transcriptome analysis of human alveolar and monocyte-derived macrophages over time in response to Mycobacterium tuberculosis infection.
Specimen part, Treatment, Subject, Time
View SamplesWe used microarrays to identify the gene expression changes after SET knockdown in ESCs and 4 day RA differentiated ESCs
Alternative SET/TAFI Promoters Regulate Embryonic Stem Cell Differentiation.
Specimen part
View SamplesThe NEET proteins mitoNEET (mNT) and nutrient-deprivation autophagy factor-1 (NAF-1) are required for cancer cell proliferation and resistance to oxidative stress. MitoNEET and NAF-1 are also implicated in a number of other human pathologies including diabetes, neurodegeneration and heart disease, as well as in development, differentiation and aging. Previous studies suggested that mNT and NAF-1 could function in the same pathway in cancer cells, preventing the over-accumulation of iron and reactive oxygen species (ROS) in mitochondria. Nevertheless, it is unknown whether these two proteins interact in cells, and how they mediate their function. Here we demonstrate, using yeast two-hybrid, in vivo bimolecular fluorescence complementation (BiFC), direct coupling analysis (DCA), RNA- sequencing, ROS and iron imaging, and single and double shRNA lines with suppressed mNT, NAF-1 and mNT/NAF-1 expression, that mNT and NAF-1 interact in cancer cells and function in the same cellular pathway. We further show using an in vitro cluster transfer assay that mNT can transfer its clusters to NAF-1. Our study suggests that mNT and NAF-1 could function as part of an iron-sulfur (2Fe-2S) cluster relay to maintain the levels of iron and Fe-S clusters under control in the mitochondria of cancer cells, thereby preventing the activation of apoptosis and/or autophagy and thus promoting rapid cellular proliferation. Overall design: Examination of the effect of suppression of mNT in the breast cancer cell line MCF-7. Two sample types were analyzed, MCF-7 suppressed for mNT and MCF-7 Empty vector control, three replicates for each.
Interactions between mitoNEET and NAF-1 in cells.
Specimen part, Cell line, Subject
View SamplesNutrient autophagy factor 1 (NAF-1) is an iron-sulfur protein found on the outer mitochondrial membrane and the ER. Recent studies highlighted an important role for NAF-1 in regulating autophagy via interaction with BCL-2. We recently reported that the level of NAF-1 is elevated in cancer cells and that NAF-1 is required for tumor growth. Here we report that shRNA suppression of NAF-1 results in the activation of apoptosis in xenograft tumors and cancer cells grown in culture. Suppression of NAF-1 resulted in a depletion in the cytosolic iron pool, facilitated uptake of iron, and accumulation of iron and ROS in mitochondria, a shift to glycolysis and glutaminolysis, and the activation of cellular stress pathways associated with HIF1a, AMPK and mTOR. Suppression of NAF-1 in breast cancer cells appears therefore to reduce their tumorigenicity by interfering with cellular iron distribution and energy metabolism resulting in the activation of apoptosis. Overall design: Examination of the effect of suppression of NAF-1 in the breast cancer cell line MCF-7. Two sample types were analyzed, MCF-7 suppressed for NAF-1 and MCF-7 Empty vector control, three replicates for each.
Activation of apoptosis in NAF-1-deficient human epithelial breast cancer cells.
No sample metadata fields
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