Disruption of local iron homeostasis is a common feature of neurodegenerative diseases. We focused on dopaminergic neurons, asking how iron transport proteins modulate iron homeostasis in vivo. Inactivation of the transmembrane iron exporter ferroportin had no apparent consequences. However, loss of the transferrin receptor 1, involved in iron uptake, caused profound, age-progressive neurodegeneration with features similar to Parkinsons disease. There was gradual loss of dopaminergic projections in the striatum with subsequent death of dopaminergic neurons in the substantia nigra. After depletion of 30% of the neurons the mice developed neurobehavioral parkinsonism, with evidence of mitochondrial dysfunction and impaired mitochondrial autophagy. Molecular analysis revealed strong signatures indicative of attempted axonal regeneration, a metabolic switch to glycolysis and the unfolded protein response. We speculate that cellular iron deficiency may contribute to neurodegeneration in human patients
Altered dopamine metabolism and increased vulnerability to MPTP in mice with partial deficiency of mitochondrial complex I in dopamine neurons.
Age, Specimen part
View SamplesIn order to elucidate the molecular mechanisms underlying individual variation in sensitivity to ethanol we profiled the prefrontal cortex transcriptomes of two inbred strains that exhibit divergent responses to acute ethanol, the C57BL6/J (B6) and DBA/2J (D2) strains, as well as 27 members of the BXD recombinant inbred panel, which was derived from a B6 x D2 cross. With this dataset we were able to identify several gene co-expression networks that were robustly altered by acute ethanol across the BXD panel. These ethanol-responsive gene-enriched networks were heavily populated by genes regulating synaptic transmission and neuroplasticity, and showed strong genetic linkage to discreet chromosomal loci. Network-based measurements of node importance identified several hub genes as established regulators of ethanol response phenotypes, while other hubs represent novel candidate modulators of ethanol responses.
Genetic dissection of acute ethanol responsive gene networks in prefrontal cortex: functional and mechanistic implications.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide screen reveals APC-associated RNAs enriched in cell protrusions.
No sample metadata fields
View SamplesEthanol inhibits the proliferation of neural stem cells in the fetal, adolescent, and adult brain. The consequences are cognitive deficits associated with fetal alcohol spectrum disorder and alcohol use disorder. We tested the hypothesis that ethanol affects progression through cell cycle checkpoints by differentially modifying transcriptional processes. Monolayer cultures of NS-5 neural stem cells were treated for 48 hr with the mitogenic agent FGF2 or the anti-mitogenic TGF1 in the absence or presence of ethanol. Cell cycle elongation was induced by a global down-regulation of genes involved in cell cycle progression, including the cyclin E system. Checkpoint regulation occurred downstream of p21 and Jun-oncogene signaling cascades. Thus, ethanol can affect cell cycle progression by altering transcript expression of strategic genes downstream of the G1/S checkpoint.
Ethanol-induced methylation of cell cycle genes in neural stem cells.
Specimen part, Treatment
View SamplesThe goal of the study was to identify on a genome-wide scale RNAs that are enriched at the leading edge of migrating cells. For this, we employed a fractionation method in which cells are plated on a microporous filter whose bottom side only is coated with fibronectin. The cells thus polarize and extend pseudopodial protrusions towards the bottom surface. These protruding pseudopodia can then be physically isolated from the bottom surface of the filter and their contents compared with the remaining cell bodies, which are isolated from the upper surface of the filter.
Genome-wide screen reveals APC-associated RNAs enriched in cell protrusions.
No sample metadata fields
View SamplesSignaling by the cytokine LIF and its downstream transcription factor, STAT3, prevents differentiation of pluripotent embryonic stem cells (ESCs) by opposing MAP kinase signaling. This contrasts with most cell types where STAT3 signaling induces differentiation. We find that STAT3 binding across the pluripotent genome is dependent upon Brg, the ATPase subunit of a specialized chromatin remodeling complex (esBAF) found in ESCs. Brg is required to establish chromatin accessibility at STAT3 binding targets, in essence preparing these sites to respond to LIF signaling. Moreover, Brg deletion leads to rapid Polycomb (PcG) binding and H3K27me3-mediated silencing of many Brg-activated targets genome-wide, including the target genes of the LIF signaling pathway. Hence, one crucial role of Brg in ESCs involves its ability to potentiate LIF signaling by opposing PcG. Contrary to expectations, Brg also facilitates PcG function at classical PcG target including all four Hox loci, reinforcing their repression in ESCs. These findings reveal that esBAF does not simply antagonize PcG, but rather, the two chromatin regulators act both antagonistically and synergistically with the common goal of supporting pluripotency.
esBAF facilitates pluripotency by conditioning the genome for LIF/STAT3 signalling and by regulating polycomb function.
Cell line, Treatment
View SamplesFast-spiking (FS) interneurons are important elements of neocortical circuitry that constitute the primary source of synaptic inhibition in adult cortex and impart temporal organization on ongoing cortical activity. The highly specialized intrinsic membrane and firing properties that allow cortical FS interneurons to perform these functions are attributable to equally specialized gene expression, which is ultimately coordinated by cell-type-specific transcriptional regulation. Although embryonic transcriptional events govern the initial steps of cell-type specification in most cortical interneurons, including FS cells, the electrophysiological properties that distinguish adult cortical cell types emerge relatively late in postnatal development, and the transcriptional events that drive this maturational process are not known. To address this, we used mouse whole-genome microarrays and whole-cell patch clamp to characterize the transcriptional and electrophysiological maturation of cortical FS interneurons between postnatal day 7 (P7) and P40. We found that the intrinsic and synaptic physiology of FS cells undergoes profound regulation over the first 4 postnatal weeks and that these changes are correlated with primarily monotonic but bidirectional transcriptional regulation of thousands of genes belonging to multiple functional classes. Using our microarray screen as a guide, we discovered that upregulation of two-pore K leak channels between P10 and P25 contributes to one of the major differences between the intrinsic membrane properties of immature and adult FS cells and found a number of other candidate genes that likely confer cell-type specificity on mature FS cells.
Transcriptional and electrophysiological maturation of neocortical fast-spiking GABAergic interneurons.
Specimen part
View SamplesCardiac disease accounts for the largest proportion of adult mortality and morbidity in the industrialized world. However, progress toward improved clinical treatments is hampered by an incomplete understanding of the genetic programs controlling early cardiogenesis. To better understand this process, we set out to identify genes whose expression is enriched within early cardiac fated populations, obtaining the transcriptional signatures of mouse embryonic stem cells (mESCs) differentiating along a cardiac path.
Efficient array-based identification of novel cardiac genes through differentiation of mouse ESCs.
No sample metadata fields
View SamplesMouse embryonic stem cells can differentiate in vitro into spontaneously contracting cardiomyocytes. The main objective of this study was to investigate cardiogenesis in cultures of differentiating embryonic stem cells (ESCs) and to determine how closely it mimics in vivo cardiac development. We identified and isolated a population of cardiac progenitor cells (CPCs) through the use of a reporter DNA construct that allowed the expression of a selectable marker under the control of the Nkx2.5 enhancer. We proceeded to characterize these CPCs by examining their capacity to differentiate into cardiomyocytes and to proliferate. We then performed a large-scale temporal microarray expression analysis in order to identify genes that are uniquely upregulated or downregulated in the CPC population. We determined that the transcriptional profile of the mESC derived CPCs was consistent with pathways known to be active during embryonic cardiac development. We conclude that in vitro differentiation of mESCs recapitulates the early steps of mouse cardiac development.
Mouse ES cell-derived cardiac precursor cells are multipotent and facilitate identification of novel cardiac genes.
No sample metadata fields
View SamplesContinuous regeneration of digestive enzyme (zymogen) secreting chief cells is a normal aspect of stomach function that is disrupted in pre-cancerous lesions. Regulation of zymogenic cell (ZC) differentiation is poorly understood. Here we profile Parietal, Pit, and Zymogenic cells for comparison and study.
The maturation of mucus-secreting gastric epithelial progenitors into digestive-enzyme secreting zymogenic cells requires Mist1.
Specimen part
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