Phosphate is essential for healthy bone growth and plays an essential role in fracture repair. Although phosphate deficiency has been shown to impair fracture healing, the mechanisms involved in impaired healing are unknown. More recently, studies have shown that the effect of phosphate deficiency on the repair process varied based on the genetic strain of mice, which is not characterized.
Hypophosphatemia Regulates Molecular Mechanisms of Circadian Rhythm.
Sex, Specimen part, Time
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 SamplesHIV-associated dementia (HAD) is a syndrome occurring in HIV-infected patients with advanced disease that likely develops as a result of macrophage and microglial activation as well as other immune events triggered by virus in the central nervous system. The most relevant experimental model of HAD, rhesus macaques exhibiting SIV encephalitis (SIVE), closely reproduces the human disease and has been successfully used to advance our understanding of mechanisms underlying HAD. In this study we integrate gene expression data from uninfected and SIV-infected hippocampus with a human protein interaction network and discover modules of genes whose expression patterns distinguish these two states, to facilitate identification of neuronal genes that may contribute to SIVE/HIV cognitive deficits. Using this approach we identify several downregulated candidate genes and select one, EGR1, a key molecule in hippocampus-related learning and memory, for further study. We show that EGR1 is downregulated in SIV-infected hippocampus and that it can be downregulated in differentiated human neuroblastoma cells by treatment with CCL8, a product of activated microglia. Integration of expression data with protein interaction data to discover discriminatory modules of interacting proteins can be usefully employed to prioritize differentially expressed genes for further study. Investigation of EGR1, selected in this manner, indicates that its downregulation in SIVE may occur as a consequence of the host response to infection, leading to deficits in cognition.
An integrated systems analysis implicates EGR1 downregulation in simian immunodeficiency virus encephalitis-induced neural dysfunction.
Sex
View SamplesWe describe a chemical method to label and purify 4-thiouridine (s4U) -containing RNA. We demonstrate that methanethiolsulfonate (MTS) reagents form disulfide bonds with s4U more efficiently than the commonly used HPDP-biotin, leading to higher yields and less biased enrichment. This increase in efficiency allowed us to use s4U-labeling to study global microRNA (miRNA) turnover in proliferating cultured human cells without perturbing global miRNA levels or the miRNA processing machinery. This improved chemistry will enhance methods that depend on tracking different populations of RNA such as 4-thiouridine-tagging to study tissue-specific transcription and dynamic transcriptome analysis (DTA) to study RNA turnover. Overall design: s4U metabolic labeling of RNA in 293T cells, followed by biochemical enrichment of labeled RNA with two biotinylation reagents, RNAs >200nt and miRNAs in separate experiments
Tracking Distinct RNA Populations Using Efficient and Reversible Covalent Chemistry.
No sample metadata fields
View SamplesCompared differentially express genes by sex in mouse for the following tissues: hypothalamus, liver, kidney, ovaries and testis (3 biological x 2 technical replicates for each tissues/sex). We used Affymetrix MOE430A Genechip arrays.
Major molecular differences between mammalian sexes are involved in drug metabolism and renal function.
Sex, Specimen part
View SamplesWe profiled RNA expression in human iPSC-derived ventricular and atrial cardiomyocytes Overall design: 4 biological replicates of human iPSC-derived ventricular cardiomyocytes and 4 biological replicates of iPSC-derived atrial cardiomyocytes (from 3 individual iPSC lines)
Deep phenotyping of human induced pluripotent stem cell-derived atrial and ventricular cardiomyocytes.
Specimen part, Cell line, Subject
View SamplesBackground: West Nile virus is an emerging infection of biodefense concern and there are no available treatments or vaccines. Here we used a high-throughput method based on a novel gene expression analysis, RNA-Seq, to give a global picture of differential gene expression by primary human macrophages of 10 healthy donors infected in vitro with WNV. Results: From a total of 50 million reads per sample, we employed a Bayesian hierarchical mixture model to identify 4,026 transcripts that were differentially expressed after infection. Both predicted and novel gene changes were detected, as were gene isoforms, and while many of the genes were expressed by all donors, some were unique. Knock-down of genes not previously known to be associated with WNV resistance identified their critical role in control of viral infection. Conclusions: Our study distinguishes both common gene pathways as well as novel cellular responses. Such analysis will be valuable for translational studies of susceptible and resistant individuals -- and for targeting therapeutics -- in multiple biological settings. Overall design: Differential gene expression by primary human macrophages of 10 healthy donors infected in vitro with WNV were generated by RNA-Seq.
Identification of genes critical for resistance to infection by West Nile virus using RNA-Seq analysis.
Specimen part, Treatment, Subject
View SamplesProper functioning of tissues requires cells to behave in uniform, well-organized ways. Conversely, many diseases involve increased cellular heterogeneity due to genetic and epigenetic alterations. Defining the mechanisms that counteract phenotypic variability is therefore critical to understand how tissues sustain homeostasis. Here, we carried out a single-cell resolution screen of zebrafish embryonic blood vessels upon mutagenesis of single microRNA (miRNA) genes and multi-gene miRNA families. We found that miRNA mutants exhibit a profound increase in cellular phenotypic variability of specific vascular traits. Genome-wide analysis of endothelial miRNA target genes identified antagonistic regulatory nodes of vascular growth and morphogenesis signaling that allow variable cell behaviors when derepressed. Remarkably, lack of such miRNA activity greatly sensitized the vascular system to microenvironmental changes induced by pharmacological stress. We uncover a previously unrecognized role of miRNAs as a widespread protective mechanism that limits variability in cellular phenotypes. This discovery marks an important advance in our comprehension of how miRNAs function in the physiology of higher organisms. Overall design: Analysis of differential genes expression in Zebrafish endothelial cells for 4 different developmental stages
MicroRNAs Establish Uniform Traits during the Architecture of Vertebrate Embryos.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Systems Analysis of Immunity to Influenza Vaccination across Multiple Years and in Diverse Populations Reveals Shared Molecular Signatures.
Specimen part, Subject, Time
View SamplesSystems approaches have been used to describe molecular signatures driving immunity to influenza vaccination in humans.
Systems Analysis of Immunity to Influenza Vaccination across Multiple Years and in Diverse Populations Reveals Shared Molecular Signatures.
Specimen part, Subject, Time
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