We compare transcriptomic profiles of human induced pluripotent stem cells (iPSCs), motor neurons (MNs) in vitro differentiated from iPSCs or human ESCs containing a HB9::GFP reporter for MNs, and human fetal spinal cords.
ALS disrupts spinal motor neuron maturation and aging pathways within gene co-expression networks.
Sex
View SamplesWhile the hypothalamo-pituitary-adrenal axis (HPA) activates a general stress response by increasing glucocorticoid (Gc) synthesis, biological stress resulting from infections triggers the inflammatory response through production of cytokines. The pituitary gland integrates some of these signals by responding to the pro-inflammatory cytokines IL6 and LIF and to a negative Gc feedback loop. The present work used whole-genome approaches to define the LIF/STAT3 regulatory network and to delineate cross-talk between this pathway and Gc action. Genome-wide ChIP-chip identified 3 449 STAT3 binding sites, whereas 2 396 genes regulated by LIF and/or Gc were found by expression profiling. Surprisingly, LIF on its own changed expression of only 85 genes but the joint action of LIF and Gc potentiated the expression of more than a thousand genes. Accordingly, activation of both LIF and Gc pathways also potentiated STAT3 and GR recruitment to many STAT3 targets. Our analyses revealed an unexpected gene cluster that requires both stimuli for delayed activation: 83% of the genes in this cluster are involved in different cell defense mechanisms. Thus, stressors that trigger both general stress and inflammatory responses lead to activation of a stereotypic innate cellular defense response.
Regulatory network analyses reveal genome-wide potentiation of LIF signaling by glucocorticoids and define an innate cell defense response.
Specimen part, Time
View SamplesExpansions of a hexanucleotide repeat (GGGGCC) in the noncoding region of the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Decreased expression of C9orf72 is seen in expansion carriers, suggesting loss of function may play a role in disease. We find that two independent mouse lines lacking the C9orf72 ortholog (3110043O21Rik) in all tissues developed normally and aged without motor neuron disease. Instead, C9orf72 null mice developed progressive splenomegaly and lymphadenopathy with accumulation of engorged macrophage-like cells. C9orf72 expression was highest in myeloid cells, and loss of C9orf72 led to lysosomal accumulation and altered immune responses in macrophages and microglia, with age-related neuroinflammation similar to C9orf72 ALS but not sporadic ALS patient tissue. Thus, C9orf72 is required for normal function of myeloid cells, and altered microglial function may contribute to neurodegeneration in C9orf72 expansion carriers. Overall design: To compare the RNA Seq profiles from the lumbar region of spinal cords from mice lacking one copy or both copies of the C9orf72 ortholog (3110043O21Rik) compared to wild type control with two copies at 3 months (n=3) and 17 months (n=4).
C9orf72 is required for proper macrophage and microglial function in mice.
Specimen part, Cell line, Subject
View SamplesPitx1, critical regulator of a limited hindlimb-specific gene network, targets the limb development program common to both fore- and hindlimbs in order to implement hindlimb-specific limb morphology. Overall design: The gene regulatory networks governing forelimb vs. hindlimb development in mouse were investigated using expressing profiling of morphologically stage-matched e10.5 forelimbs and e11.0 hindlimbs, ChIPseq of chromatin marks, and ChIPseq of limb-specific transcription factors Pitx1 and Tbx5. The makeup of the Pitx1-directed components of the hindlimb gene network were investigated using expression profiling of Pitx1 null hindlimbs at two stages (e11.0 and e11.5).
Regulatory integration of Hox factor activity with T-box factors in limb development.
Specimen part, Cell line, Subject
View SamplesDeployment of a cell-specifying enhancer repertoire by the pioneer factor Pax7 The establishment and maintenance of cell identity depends on implementation of stable cell-specific chromatin landscapes. Pioneer transcription factors establish new cell fate competences by triggering chromatin remodeling during development. Here, we used pituitary cell specification to define the salient features of pioneer action. Comparison of purified pituitary cells of different lineages showed that chromatin accessibility differs at enhancers rather than promoters. The pioneer factor Pax7 specifies one pituitary lineage identity by opening a specific repertoire of enhancers that are distinct from the myogenic targets of Pax7. Pax7 binds its pioneer targets rapidly and days before chromatin remodeling and gene activation. Finally, enhancers opened by Pax7-dependent chromatin remodeling exhibit loss of DNA methylation and they acquire long term epigenetic memory. The present work identifies enhancer pioneering as a critical feature for cell fate specification and maintenance. Overall design: RNA extraction followed by high throughput sequencing (RNA-seq)
Pioneer factor Pax7 deploys a stable enhancer repertoire for specification of cell fate.
Specimen part, Cell line, Treatment, Subject
View SamplesThe combinatorial expression of the Hox genes along the body axes, referred to as the HOX code, is a major determinant of cell fate and plays a prevailing role in generating the animal body plan. In developing limb buds, the paralogous group 13 genes of the HoxA and HoxD clusters are essential for patterning the distal-most limb structures, the digits. Inactivation of HOXA13 and HOXD13 transcription factors (HOX13) leads to complete digit agenesis in mice, but how HOX13 regulate transcriptional outcomes and confer identity to the distal-most limb cells has remained elusive. Here we performed genome-wide profiling of HOX13 by chromatin immunoprecipitation and analyzed the transcriptome and chromatin state of wild type early and late-distal limb buds, as well as Hoxa13-/-;Hoxd13-/- compound mutant limb buds. Our results show that inactivation of HOX13 impairs the activation and repression of putative cis-regulatory modules specific to the late-distal limb cells. Loss of HOX13 also disrupts the specific, spatial patterning of gene expression along the proximal-distal axis of the developing limb buds. These results show that proper termination of the early limb transcriptional program and activation of the late-distal limb program are coordinated by the dual action of HOX13 on cis-regulatory modules. Overall design: Totla mRNAs from dissected distal parts of e11.5 forelimb, of wild-type as well as Hoxa13-/-;Hoxd13-/- mice
Regulatory integration of Hox factor activity with T-box factors in limb development.
Specimen part, Cell line, Subject
View SamplesRenal failure is characterized by important biological changes resulting in profound pleomorphic physiological effects termed uremia, whose molecular causation is not well understood. The data was used to study gene expression changes in uremia using whole genome microarray analysis of peripheral blood from subjects with end-stage renal failure (n=63) and healthy controls (n=20) to obtain insight into the molecular and biological causation of this syndrome.
Alteration of human blood cell transcriptome in uremia.
Sex, Specimen part, Disease, Disease stage, Race
View SamplesAcute cardiac allograft rejection is a serious complication of heart transplantation. Investigating molecular processes in whole blood via microarrays is a promising avenue of research in transplantation, particularly due to the non-invasive nature of blood sampling. However, whole blood is a complex tissue and the consequent heterogeneity in composition amongst samples is ignored in traditional microarray analysis. This complicates the biological interpretation of microarray data. Here we have applied a statistical deconvolution approach, cell-specific significance analysis of microarrays (csSAM), to whole blood samples from subjects either undergoing acute heart allograft rejection (AR) or not (NR). We identified eight differentially expressed probe-sets significantly correlated to monocytes (mapping to 6 genes, all down-regulated in ARs versus NRs) at a false discovery rate (FDR) <= 15%. None of the genes identified are present in a biomarker panel of acute heart rejection previously published by our group and discovered in the same data.
White blood cell differentials enrich whole blood expression data in the context of acute cardiac allograft rejection.
No sample metadata fields
View SamplesRegulation of cell-cell junction formation and regulation of cell migration were enriched among EMT (Epithelial-Mesenchymal Transition)-associated alternatively splicing events. Our analysis suggested that most EMT-associated alternative splicing events are regulated by one or more members of the RBFOX, MBNL, CELF, hnRNP or ESRP classes of splicing factors. The EMT alternative splicing signature was confirmed in human breast cancer cell lines, which could be classified into basal and luminal subtypes based exclusively on their EMTassociated splicing pattern. Expression of EMT-associated alternative mRNA transcripts was also observed in primary breast cancer samples, indicating that EMT-dependent splicing changes occur commonly in human tumors. The functional significance of EMT-associated alternative splicing was tested by expression of the epithelial-specific splicing factor ESRP1 or depletion of RBFOX2 in mesenchymal cells, both of which elicited significant changes in cell morphology and motility towards an epithelial phenotype, suggesting that splicing regulation alone can drive critical aspects of EMT-associated phenotypic changes. The molecular description obtained here may aid in the development of new diagnostic and prognostic markers for analysis of breast cancer progression. Overall design: Examination of transcriptomes of HMLE/Twist-ER before and after induction of EMT by tamoxifen
An EMT-driven alternative splicing program occurs in human breast cancer and modulates cellular phenotype.
No sample metadata fields
View SamplesAmyotrophic lateral sclerosis (ALS) is a severe neurodegenerative condition characterized by loss of motor neurons in the brain and spinal cord. Expansions of a hexanucleotide repeat (GGGGCC) in the noncoding region of the C9ORF72 gene are the most common cause of the familial form of ALS (C9-ALS), as well as frontotemporal lobar degeneration and other neurological diseases. How the repeat expansion causes disease remains unclear, with both loss of function (haploinsufficiency) and gain of function (either toxic RNA or protein products) proposed. We report a cellular model of C9-ALS with motor neurons differentiated from induced pluripotent stem cells (iPSCs) derived from ALS patients carrying the C9ORF72 repeat expansion. No significant loss of C9ORF72 expression was observed, and knockdown of the transcript was not toxic to cultured human motor neurons. Transcription of the repeat was increased, leading to accumulation of GGGGCC repeat–containing RNA foci selectively in C9-ALS iPSC-derived motor neurons. Repeat-containing RNA foci colocalized with hnRNPA1 and Pur-a, suggesting that they may be able to alter RNA metabolism. C9-ALS motor neurons showed altered expression of genes involved in membrane excitability including DPP6, and demonstrated a diminished capacity to fire continuous spikes upon depolarization compared to control motor neurons. Antisense oligonucleotides targeting the C9ORF72 transcript suppressed RNA foci formation and reversed gene expression alterations in C9-ALS motor neurons. These data show that patient-derived motor neurons can be used to delineate pathogenic events in ALS. Overall design: Transcriptome profiling from iPSC derived motor neurons compared to controls
Targeting RNA foci in iPSC-derived motor neurons from ALS patients with a C9ORF72 repeat expansion.
No sample metadata fields
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