Huntingtons Disease (HD) is an inherited neurodegenerative disease caused by a glutamine repeat expansion in huntingtin protein. Transcriptional deregulation and altered energy metabolism have been implicated in HD pathogenesis. We report here that mutant huntingtin causes disruption of mitochondrial function by inhibiting expression of PGC-1a, a transcriptional coactivator that regulates several metabolic processes including mitochondrial biogenesis and respiration. Mutant huntingtin represses PGC-1a gene transcription by associating with the promoter and interfering with the CREB/TAF4-dependent transcriptional pathway critical for the regulation of PGC-1a gene expression. Crossbreeding of PGC-1a knockout mice with HD knock-in mice leads to increased neurodegeneration of striatal neurons and motor abnormalities in the HD mice. Importantly, expression of PGC-1a partially reverses the toxic effects of mutant huntingtin in cultured striatal neurons. Moreover, lentiviral-mediated delivery of PGC-1a in the striatum provides neuroprotection in the transgenic HD mice. These studies suggest a key role for PGC-1a in the control of energy metabolism in the early stages of HD pathogenesis.
Transcriptional repression of PGC-1alpha by mutant huntingtin leads to mitochondrial dysfunction and neurodegeneration.
Sex, Age, Specimen part
View SamplesCTCF/cohesin play a central role in insulator function and higher-order chromatin organization of mammalian genomes. Recent studies identified a correlation between the orientation of CTCF-binding sites (CBSs) and chromatin loops. To test the functional significance of this observation, we combined CRISPR/Cas9-based genomic-DNA-fragment editing with chromosome-conformation-capture experiments to show that the location and relative orientations of CBSs determine the specificity of long-range chromatin looping in mammalian genomes, using protocadherin (Pcdh) and ß-globin as model genes. Inversion of CBS elements within the Pcdh enhancer reconfigures the topology of chromatin loops between the distal enhancer and target promoters, and alters gene-expression patterns. Thus, although enhancers can function in an orientation-independent manner in reporter assays, in the native chromosome context the orientation of at least some enhancers carrying CBSs can determine both the architecture of topological chromatin domains and enhancer/promoter specificity. The findings reveal how 3D chromosome architecture can be encoded by genome sequence. Overall design: HEC-1B mRNA profiles of HS5-1 Inversion
CRISPR Inversion of CTCF Sites Alters Genome Topology and Enhancer/Promoter Function.
No sample metadata fields
View SamplesTranscriptional dysregulation is an early feature of Huntington''s disease (HD). We observed gene-specific changes in H3K4me3 at transcriptionally repressed promoters in R6/2 mouse and human HD brain. Genome-wide analysis showed a novel chromatin signature for this mark. Reducing the levels of the H3K4 demethylase SMCX/Jarid1c in primary neurons reversed down-regulation of key neuronal genes caused by mutant Huntingtin (Htt) expression. Finally, reduction of SMCX/Jarid1c in primary neurons from BACHD mice or the single Jarid1 in a Drosophila HD model was protective. Therefore, targeting this epigenetic signature may be an effective strategy to ameliorate the consequences of HD. Overall design: mRNA-seq in wild type and R6/2 cortex and striatum at 8 and 12 weeks.
Targeting H3K4 trimethylation in Huntington disease.
Age, Specimen part, Subject
View SamplesGenome-wide analyses have identified thousands of long non-coding RNAs (lncRNAs). Malat1 (Metastasis Associated Lung Adenocarcinoma Transcript 1) is among the most abundant lncRNAs whose expression is altered in numerous cancers. Here we report that genomic loss, as well as systemic knockdown of Malat1 using antisense oligonucleotides, in the MMTV-PyMT mouse mammary carcinoma model results in slower tumor growth accompanied by differentiation into highly cystic tumors and a significant reduction in lung metastasis. Further, Malat1 loss results in a reduction of branching morphogenesis in MMTV-PyMT and Her2/neu amplified tumor organoids consistent with the in vivo reduction in lung metastasis. At the molecular level, Malat1 knockdown results in alterations in gene expression and changes in splicing patterns of genes involved in differentiation and pro-tumorigenic signaling pathways. Together, these data indicate that the lncRNA Malat1 regulates critical processes in mammary cancer pathogenesis and represents a promising therapeutic target for inhibiting breast cancer metastasis. Overall design: Transcriptome profiles of tumors and organoids after Malat1 knockdown using antisense olgonucleotides (ASOs).
Differentiation of mammary tumors and reduction in metastasis upon Malat1 lncRNA loss.
No sample metadata fields
View SamplesReprogramming somatic cells to induced pluripotent stem cells (iPSCs) sets their identity back to an embryonic age. This presents a fundamental hurdle for modeling late-onset disorders using iPSC-derived cells. We therefore developed a strategy to induce age-like features in multiple iPSC-derived lineages and tested its impact on modeling Parkinson’s disease (PD). We first describe markers that predict fibroblast donor age and observed the loss of these age-related markers following iPSC induction and re-differentiation into fibroblasts. Remarkably, age-related markers were readily induced in iPSC-derived fibroblasts or neurons following exposure to progerin including dopamine neuron-specific phenotypes such as neuromelanin accumulation. Induced aging in PD-iPSC-derived dopamine neurons revealed disease phenotypes requiring both aging and genetic susceptibility such as frank dendrite degeneration, progressive loss of tyrosine-hydroxylase expression and enlarged mitochondria or Lewy body-precursor inclusions. Our study presents a strategy for inducing age-related cellular properties and enables the modeling of late-onset disease features. Overall design: Induced pluripotent stem cell-derived midbrain dopamine neurons from a young and old donor overexpressing either GFP or Progerin.
Human iPSC-based modeling of late-onset disease via progerin-induced aging.
No sample metadata fields
View SamplesEstablishing reliable biomarkers for assessing and validating clinical diagnosis at early prodromal stages of Parkinsons disease is crucial for developing therapies to slow or halt disease progression. Here, we present the largest study to date using whole blood gene expression profiling from over 500 individuals to identify an 87-gene blood-based signature. Our gene signature effectively differentiates between idiopathic PD patients and controls in both a validation cohort and an independent test cohort, and further highlights mitochondrial metabolism and ubiquitination/proteasomal degradation as potential pathways disrupted in Parkinsons disease.
Analysis of blood-based gene expression in idiopathic Parkinson disease.
Sex, Specimen part, Subject
View SamplesHuman ILCs are classically categorized into five subsets; cytotoxic CD127-CD94+ NK cells and non-cytotoxic CD127+CD94-, ILC1s, ILC2s, ILC3s and LTi cells. Here, we identify a novel subset within the CD127+ ILC population, characterized by the expression of the cytotoxic marker CD94. These CD94+ ILCs strongly resemble conventional ILC3s in terms of phenotype, transcriptome and cytokine production, but are highly cytotoxic. IL-15 was unable to induce differentiation of CD94+ ILCs towards mature NK cells. Instead, CD94+ ILCs retained RORγt, CD127 and CD200R expression and produced IL-22 in response to IL-15. Culturing non-cytotoxic CD127+ ILC1s or ILC3s with IL-12 induced upregulation of CD94 and cytotoxic activity, effects that were not observed with IL-15 stimulation. Thus, human helper ILCs can acquire a cytotoxic program without differentiating into NK cells.
Identification of human cytotoxic ILC3s.
Specimen part, Subject
View SamplesSmall molecule splicing modifiers have been extensively described which target the generic splicing machinery and thus have low target specificity. We have identified potent splicing modifiers with unprecedented high selectively, correcting the splicing deficit of the SMN2 (survival motor neuron 2) gene in Spinal Muscular Atrophy (SMA). Here we show that they directly bind to two sites of the SMN2 pre-mRNA, thereby stabilizing a novel ribonucleoprotein (RNP) complex in the SMN2 gene that is critical for the high target specificity of these small molecules over other genes. In addition to the therapeutic potential of these molecules for treatment of SMA, our work may have wide-ranging consequences for further research to identify small molecules that target splicing correction of specific genes by interacting with tertiary RNA structures. Overall design: mRNA profiling of type I SMA fibroblasts treated with NVS-SM1
Binding to SMN2 pre-mRNA-protein complex elicits specificity for small molecule splicing modifiers.
Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene Expression Profiling of Ewing Sarcoma Tumors Reveals the Prognostic Importance of Tumor-Stromal Interactions: A Report from the Children's Oncology Group.
Sex, Age, Disease
View SamplesFor the current study we performed whole genome expression profiling on two independent cohorts of clinically annotated, localized Ewing sarcoma (ES) tumors in an effort to identify and validate prognostic gene signatures. ES specimens were obtained from the Childrens Oncology Group (COG) and whole genome expression profiling performed using Affymetrix Human Exon 1.0 ST arrays. Lists of differentially expressed genes between survivors and non-survivors were used to identify prognostic gene signatures
Gene Expression Profiling of Ewing Sarcoma Tumors Reveals the Prognostic Importance of Tumor-Stromal Interactions: A Report from the Children's Oncology Group.
Sex, Disease
View Samples