Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive weakness from loss of motor neurons. The fundamental pathogenic mechanisms are unknown and recent evidence is implicating a significant role for abnormal exon splicing and RNA processing. Using new comprehensive genomic technologies, we studied exon splicing directly in 12 sporadic ALS and 10 control lumbar spinal cords acquired by a rapid autopsy system that processed nervous systems specifically for genomic studies. ALS patients had rostral onset and caudally advancing disease and abundant residual motor neurons in this region. We created two RNA pools, one from motor neurons collected by laser capture microdissection and one from the surrounding anterior horns. From each, we isolated RNA, amplified mRNA, profiled whole-genome exon splicing, and applied advanced bioinformatics. We employed rigorous quality control measures at all steps and validated findings by qPCR. In the motor neuron enriched mRNA pool, we found two distinct cohorts of mRNA signals, most of which were up-regulated: 148 differentially expressed genes (p103) and 411 aberrantly spliced genes (p105). The aberrantly spliced genes were highly enriched in cell adhesion (p1057), especially cell-matrix as opposed to cell-cell adhesion. Most of the enriching genes encode transmembrane or secreted as opposed to nuclear or cytoplasmic proteins. The differentially expressed genes were not biologically enriched. In the anterior horn enriched mRNA pool, we could not clearly identify mRNA signals or biological enrichment. These findings, perturbed and up-regulated cell-matrix adhesion, suggest possible mechanisms for the contiguously progressive nature of motor neuron degeneration.
Sporadic ALS has compartment-specific aberrant exon splicing and altered cell-matrix adhesion biology.
Sex, Age, Specimen part
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
View SamplesTDP-43, FUS, and TAF15 are implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. We integrate CLIP-seq and RNA Bind-N-Seq technologies to discover that TAF15 binds to ~4,900 RNAs enriched for GGUA motifs. In the mouse brain, TAF15 and FUS, but not TDP-43, exhibit strikingly similar RNA binding profiles, yet they alter the expression of distinct mRNA populations upon their individual depletions. TAF15 has a minimal role in alternative splicing and instead affects RNA turnover, consistent with an enrichment of TAF15 binding sites in 3’ untranslated regions. In human stem cell-derived motor neurons, loss of both TAF15 and FUS affected mRNAs distinct from those altered by loss of either protein alone, revealing redundant roles for TAF15 and FUS in maintaining mRNA levels. Furthermore, concomitant rather than individual depletion of TAF15 and FUS more closely resembles RNA profiles of motor neurons derived from FUS R521G ALS patients or from late-stage, sporadic ALS patients. Our study reveals convergent and divergent mechanisms by which FUS, TAF15 and TDP-43 affects RNA metabolism in neurological disease. Overall design: RNA-seq, CLIP-seq and arrays in mouse and human against TAF15 knockdowns This Series represents RNA-seq sample(s).
Distinct and shared functions of ALS-associated proteins TDP-43, FUS and TAF15 revealed by multisystem analyses.
No sample metadata fields
View SamplesTDP-43, FUS, and TAF15 are implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. We integrate CLIP-seq and RNA Bind-N-Seq technologies to discover that TAF15 binds to ~4,900 RNAs enriched for GGUA motifs. In the mouse brain, TAF15 and FUS, but not TDP-43, exhibit strikingly similar RNA binding profiles, yet they alter the expression of distinct mRNA populations upon their individual depletions. TAF15 has a minimal role in alternative splicing and instead affects RNA turnover, consistent with an enrichment of TAF15 binding sites in 3’ untranslated regions. In human stem cell-derived motor neurons, loss of both TAF15 and FUS affected mRNAs distinct from those altered by loss of either protein alone, revealing redundant roles for TAF15 and FUS in maintaining mRNA levels. Furthermore, concomitant rather than individual depletion of TAF15 and FUS more closely resembles RNA profiles of motor neurons derived from FUS R521G ALS patients or from late-stage, sporadic ALS patients. Our study reveals convergent and divergent mechanisms by which FUS, TAF15 and TDP-43 affects RNA metabolism in neurological disease. Overall design: RNA-seq, CLIP-seq and arrays in mouse and human against TAF15 knockdowns This Series represents RNA-seq sample(s).
Distinct and shared functions of ALS-associated proteins TDP-43, FUS and TAF15 revealed by multisystem analyses.
No sample metadata fields
View SamplesTDP-43, FUS, and TAF15 are implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. We integrate CLIP-seq and RNA Bind-N-Seq technologies to discover that TAF15 binds to ~4,900 RNAs enriched for GGUA motifs. In the mouse brain, TAF15 and FUS, but not TDP-43, exhibit strikingly similar RNA binding profiles, yet they alter the expression of distinct mRNA populations upon their individual depletions. TAF15 has a minimal role in alternative splicing and instead affects RNA turnover, consistent with an enrichment of TAF15 binding sites in 3’ untranslated regions. In human stem cell-derived motor neurons, loss of both TAF15 and FUS affected mRNAs distinct from those altered by loss of either protein alone, revealing redundant roles for TAF15 and FUS in maintaining mRNA levels. Furthermore, concomitant rather than individual depletion of TAF15 and FUS more closely resembles RNA profiles of motor neurons derived from FUS R521G ALS patients or from late-stage, sporadic ALS patients. Our study reveals convergent and divergent mechanisms by which FUS, TAF15 and TDP-43 affects RNA metabolism in neurological disease. Overall design: RNA-seq, CLIP-seq and arrays in mouse and human against TAF15 knockdowns This Series represents RNA-seq sample(s).
Distinct and shared functions of ALS-associated proteins TDP-43, FUS and TAF15 revealed by multisystem analyses.
Specimen part, Cell line, Subject
View SamplesThe innate immune system is vital to rapidly responding to pathogens and Toll-like receptors (TLRs) are a critical component of this response. Nanovesicular exosomes play a role in immunity, but to date their exact contribution to the dissemination of the TLR response is unknown. To understand the effect of exosomal cargo released from locally stimulated cells on distal cell expression, we collected exosomes from local ovarian adenocarcinoma (HEY) cells that were either unstimulated (control-exosomes), stimulated with pIC (pIC-exosomes), or lipopolysaccharide (LPS-exosomes) for 48 hours. The three groups of exosomes were added to nave (distal) cells and the gene expression profiles were compared between local TLR stimulation (for 6 hours) and distal stimulation mediated by exosomes at the 48-hour time point
TLR-exosomes exhibit distinct kinetics and effector function.
Specimen part, Cell line, Treatment
View SamplesPurpose: The purpose of this experiment is to identify a C9-ALS/FTD specific genomic profile in fibroblast lines that is distinct from sporadic ALS without C9orf72 expansion and non-neurologic control cells. The study will then evaluate the effect on this identified profile of ASO treatment targeting the sense strand RNA transcript of the C9orf72 gene. Methods: Expression profiling was performed on RNAs from fibroblasts of four C9orf72 patients, four control individuals and four sporadic ALS patients using Multiplex Analysis of PolyA-linked Sequences method. Results: Hierarchical clustering of expression values for all genes showed that the four C9orf72 patient lines had an expression profile distinct from control and sporadic ALS lines. Statistical comparison of expression values between the four C9orf72 lines and the four control lines revealed that 122 genes were upregulated (defined by a False Discovery Rate FDR<0.05) and 34 genes were downregulated (defined by a False Discovery Rate FDR <0.05) in C9orf72 patient fibroblasts. Conclusions: A genome wide RNA signature can be defined in fibroblasts with C9orf72 expansion. ASO-mediated reduction of C9orf72 RNA levels in fibroblasts with the hexanucleotide expansion efficiently reduced accumulation of GGGGCC RNA foci. This did not, however, generate a reversal of the C9orf72 RNA profile. Overall design: Use of Multiplex Analysis of PolyA-linked Sequences to identify expression changes in fibroblasts from amyotrophic lateral sclerosis and frontotemporal dementia patients harboring an hexanucleotide expansion in the C9orf72 gene.
Targeted degradation of sense and antisense C9orf72 RNA foci as therapy for ALS and frontotemporal degeneration.
No sample metadata fields
View SamplesIn prior work we developed an optogenetic system for delivering highly precise, time-varying inputs to Ras, termed OptoSOS (Toettcher et al., 2013). This system relies on a membrane-targeted photoswitchable protein (Phy-CAAX) and a cytoplasmic Ras activator (PIF-SOScat) whose localization to the membrane can be controlled with light. In this system, Phy/PIF heterodimerization can be triggered on and off by exposure to 650 and 750 nm light, respectively. We found that this system could be used to deliver highly precise levels and dynamics of Ras/Erk signaling both in vitro and in vivo. Here, we aimed to globally assess the transcriptional response to light-activated Ras and compare it to that induced by growth factor stimulation. We stimulated NIH3T3 OptoSOS cells with either constant activating red light or PDGF and measured transcriptional responses by RNAseq. Total mRNA was collected after 0, 30, 60 and 120 minutes and used to track the dynamics of transcript abundance in both conditions. Genes were defined as upregulated if they satisfied two criteria: (i) induced at least three-fold over unstimulated cells, and (ii) induced at least two consecutive timepoints. By these criteria we detected 118 genes that were upregulated within 2 h by either PDGF or light stimulation, a comparable number of Ras-responsive genes to that found in previous studies. We found that both PDGF and light induced nearly identical profiles of gene expression, with 100/118 genes induced by PDGF and 110/118 induced by light. At each time point we found excellent agreement between the levels of gene induction in response to both stimuli. This agreement also extended to response dynamics. where hierarchical clustering revealed three classes of dynamic response: an early response peaking within 30 min, an intermediate response peaking at ~1 h, and a late response where gene expression gradually increased over the full 2 h timecourse. In all three classes, we found that light and PDGF led to highly similar expression changes over time. We thus concluded that sole stimulation of the Ras/Erk pathway by light was sufficient to recapitulate at least the first two hours of the PDGF-induced transcriptional response. Overall design: RNA-seq to measure global transcript abundance at various timepoints after PDGF stimulation or direct optogenetic activation of Ras using the OptoSOS system in NIH3T3 cells (Toettcher et al, Cell 2013). 9 samples were collected using the TruSeq library preparation kit (Illumina), multiplexed, pooled and measured in 3 lanes of an Illumina Hi-Seq 2000. Library quality was assessed by Agilent Bioanalyzer. Roughly 30-50 million reads were measured per sample across all 3 lanes. Baseline transcript abundance was measured in triplicate (0 min controls) and each successive timepoint was measured in a single collection. Genes were considered upregulated if they were induced at least 5-fold in at least two consecutive timepoints relative to their baseline abundance.
Tracing Information Flow from Erk to Target Gene Induction Reveals Mechanisms of Dynamic and Combinatorial Control.
Specimen part, Subject
View SamplesIn this experiment, we sought to analyze how the transcriptome of WT, ?5|6, and ?5|6:7|9 cells vary during differentiation of ESCs into cervical motor neurons Overall design: 3 lines (WT, ?5|6, ?5|6:7|9)
CTCF establishes discrete functional chromatin domains at the Hox clusters during differentiation.
No sample metadata fields
View SamplesWe used the microarray data to analyze host cells response on mouse macrophage cells infected with HRSV
A systems-based approach to analyse the host response in murine lung macrophages challenged with respiratory syncytial virus.
Specimen part, Time
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