Microarrays were used to examine the genome-wide expression in FIH null, VHL null and VHL/FIH double null MEFs.
The asparaginyl hydroxylase factor inhibiting HIF-1alpha is an essential regulator of metabolism.
Specimen part
View SamplesBackground: Interaction between key signaling mechanisms is important to generate the diversity in signaling output required for proper control of cellular differentiation and function, although the molecular manifestations of such cross-talk are only partially understood. Notch signaling and the cellular response to hypoxia intersect at different points in the signaling cascades, and in this report we analyze the consequences of this cross-talk at the transcriptome level. Results: Mouse ES cells were subjected to various combinations of hypoxia and/or activated Notch signaling, and the transcriptome changes could be grouped into different categories, reflecting various modes of hypoxia and Notch signaling integration. Two principal categories of novel Notch- and hypoxia-induced genes were identified: i) a larger set of genes induced by one pathway and not significantly affected by the activity status of the other pathway; and ii) a smaller set of genes co-regulated by Notch and hypoxia. In the latter category, we identified genes that were induced by hypoxia and the expression of which was enhanced by active Notch signaling. In addition, a number of genes were induced by Notch and hypoxia independently, and a final category of genes required simultaneous activation of Notch and hypoxia to be significantly induced. Several of the hypoxia- and Notch-induced genes were found to be upregulated in various forms of cancer. Conclusions: We identify novel Notch and hypoxia downstream genes and genes co-regulated by the two pathways, providing a molecular platform to better understand the intersection between the two signaling cascades in normal development and cancer.
Interactions between Notch- and hypoxia-induced transcriptomes in embryonic stem cells.
Sex, Specimen part, Treatment
View SamplesAmmonia is a toxic by-product of metabolism that causes cellular stress. Although a number of proteins are involved in adaptive stress response, specific factors that counteract ammonia-induced cellular stress and regulate cell metabolism that facilitate survival against toxicity have yet to be identified. We demonstrated that hypoxia-inducible factor-1 (HIF-1) is stabilised and activated by ammonia stress. HIF-1 activated by ammonium chloride compromises ammonia-induced apoptosis. Furthermore, we identified glutamine synthetase (GS) as a key driver of cancer cell proliferation and glutamine-dependent metabolism under ammonia stress in ovarian cancer stem-like cells expressing CD90. Interestingly, activated HIF-1 counteracts glutamine synthetase function in glutamine metabolism by facilitating glycolysis and elevating glucose dependency. Our studies reveal the hitherto unknown functions of HIF-1 in biphasic ammonia stress management in cancer stem-like cells. GS facilitates proliferation and HIF-1 contributes to metabolic remodelling in cellular energy usage resulting in attenuated proliferation but conversely promoting cell survival.
Hypoxia-inducible factor-1α promotes cell survival during ammonia stress response in ovarian cancer stem-like cells.
Specimen part, Cell line
View SamplesFacioscapulohumeral muscular dystrophy (FSHD) represents a majorunmet clinical need arising from the progressive weakness and atrophy of skeletal muscles. The dearth of adequate experimental models has severely hampered our understanding of the disease. To date, no treatment is available for FSHD. Human embryonic stem cells (hESCs) potentially represent a renewable source of skeletal muscle cells (SkMCs) and provide an alternative to invasive patient biopsies.Wedeveloped a scalable monolayer system to differentiate hESCs into mature SkMCs within 26 days, without cell sorting or genetic manipulation. Here we show that SkMCs derived from FSHD1-affected hESC lines exclusively express the FSHD pathogenic marker double homeobox 4 and exhibit some of the defects reported in FSHD. FSHD1 myotubes are thinner when compared with unaffected and Becker muscular dystrophy myotubes, and differentially regulate genes involved in cell cycle control, oxidative stress response and cell adhesion. This cellularmodelwill be a powerful tool for studying FSHDandwill ultimately assist in the development of effective treatments for muscular dystrophies.
A Human Pluripotent Stem Cell Model of Facioscapulohumeral Muscular Dystrophy-Affected Skeletal Muscles.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Efficient endoderm induction from human pluripotent stem cells by logically directing signals controlling lineage bifurcations.
Specimen part, Cell line
View SamplesThe definitive endoderm germ layer is the provenance of multiple internal organs, including the lungs, liver, pancreas and intestines. Molecular events driving initial endoderm germ layer specification and subsequent anterior-posterior patterning of endoderm into distinct organ primordia remain largely cryptic.
Efficient endoderm induction from human pluripotent stem cells by logically directing signals controlling lineage bifurcations.
Specimen part, Cell line
View SamplesWe assessed vastus lateralis muscle gene expression levels of 12 women with the metabolic syndrome before and after a 6 month exercise training program
Upregulation of skeletal muscle inflammatory genes links inflammation with insulin resistance in women with the metabolic syndrome.
Sex, Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesThe leg of healthy volunteers was locally deconditioned using three weeks of unilateral lower limb suspension (ULLS). The extremely deconditioned legs of subjects with a spinal cord injury (SCI) were trained using eight weeks of functional electrical stimulation (FES) exercise, 2-3 times per week (total 20 sessions).
Expression of genes involved in fatty acid transport and insulin signaling is altered by physical inactivity and exercise training in human skeletal muscle.
Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Antiviral Protection via RdRP-Mediated Stable Activation of Innate Immunity.
Sex, Specimen part
View SamplesPreviously, we reported that mice made transgenic for a picornaviral RdRP the 3Dpol protein of Theilers murine encephalomyelitis virus (TMEV) suppress infection by diverse viral families. How the picornaviral RdRP transgene exerted antiviral protection in vivo was not known. To investigate the molecular mechanism, we determined gene expression profiles in spinal cords of WT and RdRP transgenic mice prior to (baseline) and after (2 days) infection with Encephalomyocarditis Virus (EMCV).
Antiviral Protection via RdRP-Mediated Stable Activation of Innate Immunity.
Sex
View Samples