Increasing evidence suggests that defective RNA processing contributes to the development of amyotrophic lateral sclerosis (ALS). This may be especially true for ALS caused by a repeat expansion in C9orf72 (c9ALS), in which the accumulation of RNA foci and dipeptide-repeat proteins are expected to modify RNA metabolism. We report extensive alternative splicing (AS) and alternative polyadenylation (APA) defects in the cerebellum of c9ALS cases (8,224 AS, 1,437 APA), including changes in ALS-associated genes (e.g. ATXN2 and FUS), and cases of sporadic ALS (sALS; 2,229 AS, 716 APA). Furthermore, hnRNPH and other RNA-binding proteins are predicted as potential regulators of cassette exon AS events for both c9ALS and sALS. Co-expression and gene-association network analyses of gene expression and AS data revealed divergent pathways associated with c9ALS and sALS. Overall design: Examination transcriptiome profiles in c9orf72-associated ALS, sporadic ALS and healthy control
Repetitive element transcripts are elevated in the brain of C9orf72 ALS/FTLD patients.
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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.
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View SamplesNoncoding expansions of a hexanucleotide repeat (GGGGCC) in the C9orf72 gene are the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. Here we report transgenic mice carrying a bacterial artificial chromosome (BAC) containing the full human C9orf72 gene with either a normal allele (15 repeats) or disease-associated expansion (~100–1,000 repeats; C9-BACexp). C9-BACexp mice displayed pathologic features seen in C9orf72 expansion patients, including widespread RNA foci and repeat-associated non-ATG (RAN) translated dipeptides, which were suppressed by antisense oligonucleotides targeting human C9orf72. Nucleolin distribution was altered, supporting that either C9orf72 transcripts or RAN dipeptides promote nucleolar dysfunction. Despite early and widespread production of RNA foci and RAN dipeptides in C9-BACexp mice, behavioral abnormalities and neurodegeneration were not observed even at advanced ages, supporting the hypothesis that RNA foci and RAN dipeptides occur presymptomatically and are not sufficient to drive neurodegeneration in mice at levels seen in patients. Overall design: To compare the RNA Seq profiles from the cortex and spinal cord of transgenic mice expressing unexpanded human C9orf72 (F08, n=4), expanded human C9orf72 (F112, n=3/4), and nontransgenic controls (n=4).
C9orf72 BAC Transgenic Mice Display Typical Pathologic Features of ALS/FTD.
Specimen part, Cell line, Subject
View SamplesHow G4C2 repeat expansions in C9orf72 cause frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) is not understood. Here, we report the first mouse model to express poly(PR), a dipeptide repeat protein synthesized from expanded G4C2 repeats. Expression of GFP-(PR)50 throughout the mouse brain yielded progressive brain atrophy, neuron5 loss, loss of poly(PR)-positive cells and gliosis, culminating in motor and memory impairments. We found that poly(PR) bound DNA, localized to heterochromatin, and caused abnormal histone methylation, lamin invaginations, decreases in HP1a expression, and disruptions of HP1a liquid phases. These aberrations of histone methylation, lamins and HP1a, which regulate heterochromatin structure and gene expression, were accompanied by repetitive element10 expression and double-stranded RNA accumulation. Thus, we uncover new mechanisms by which poly(PR) contributes to c9FTD/ALS pathogenesis. Overall design: Examination of transcriptome profiles using RNA-seq on 3 month old mice expressing PR and GR polypetides with an AAV expression vector. The Poly(PR) analysis consisted of 7 mice expressing AAV-GFP-(PR)50 and 4 AAV-GFP harvest-matched controls. The Poly(GR) analysis consisted of 4 mice expressing AAV-GFP-(GR)100 and 4 AAV-GFP harvest-matched controls.
Heterochromatin anomalies and double-stranded RNA accumulation underlie <i>C9orf72</i> poly(PR) toxicity.
Sex, Age, Cell line, Subject
View SamplesTo determine a gene/molecular fingerprint of multiple myeloma (MM) endothelial cells (MMECs), also identifying some of the vascular mechanisms that govern the malignant progression from quiescent monoclonal gammopathy of undetermined significance (MGUS). A comparative gene expression profiling (GEP) was carried out on patient-derived MMECs and MGUS endothelial cells (MGECs) using the Affymetrix U133A Arrays. Expression of selective vascular markers were also validated by RT-PCR and immunoblotting analysis in primary cultures of ECs isolated from total bone marrow (BM)-mononuclear cells. Twenty-two genes were found differently expressed in MMECs compared to MGECs (with 14 down-regulated and 8 up-regulated), thus proving that molecular differences were maintained in vitro. Specific pathways analysis revealed transcriptional and protein expression changes for key regulators of extracellular matrix formation and bone remodeling, cell-adhesion, chemotaxis, angiogenesis, resistance to apoptosis, and cell-cycle regulation. Specifically, we focused on six of these genes (DIRAS3, SERPINF1, SRPX, BNIP3, IER3 and SEPW1), which were not previously functionally correlated to the overangiogenic phenotype of MMECs and disease activity. These data identified distinct EC gene expression profiles and some vascular phenotypes that could influence the remodeling of the BM-microenvironment in patients with active MM. A better understanding of the linkage between genetic and epigenetic events in MM tumor/ECs may contribute to the molecular classification of the disease, thereby identifying selective targets of more effective anti-vessel/stroma therapeutic strategies.
Gene expression profiling of bone marrow endothelial cells in patients with multiple myeloma.
Sex
View SamplesA subanalysis of the GIMEMA-MMY-3006 trial was performed to characterize treatment-emergent peripheral neuropathy (PN) in patients randomized to thalidomide-dexamethasone (TD) or bortezomib-TD (VTD) before and after double autologous transplantation (ASCT) for multiple myeloma (MM). 236 patients randomized to VTD and 238 to TD were stratified according to the emergence of grade 2 PN. Gene expression profiles (GEP) of CD138+ plasma cells were analyzed from 122 VTD-treated patients. The incidence of grade 2 PN was 35% in the VTD arm and 10% in the TD arm (p<0.001). PN resolved in 88% and 95% of patients in VTD and TD groups, respectively. Rates of complete/near complete response, progression-free and overall survival were not adversely affected by emergence of grade 2 PN. Baseline characteristics were not risk factors for PN, while GEP analysis revealed the deregulated expression of genes implicated in cytoskeleton rearrangement, neurogenesis and axonal guidance. In conclusion, in comparison with TD, incorporation of VTD into ASCT was associated with a higher incidence of PN which, however, was reversible in most of the patients and did not adversely affect their outcomes nor their ability to subsequently receive ASCT. GEP analysis suggests an interaction between myeloma genetic profiles and development of VTD-induced PN.
Bortezomib- and thalidomide-induced peripheral neuropathy in multiple myeloma: clinical and molecular analyses of a phase 3 study.
Specimen part, Disease, Disease stage
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Dietary methanol regulates human gene activity.
Sex, Age, Specimen part, Subject
View SamplesThis study aimed to quantify the regulation of transcripts in the hairy skin of the back of adult rats in the condition of loss of sensory and autonomic (sympathetic) innervation (i.e., denervated). Denervated skin has reduced wound healing capacity, reduced proliferation of epidermal progenitor cells, and also expresses factors that regulate ingrowth of sensory and sympathetic axons from neighboring regions of innervated skin. It was expected that this quantification f transcript regulation would offer insight into the general and specific mechanisms that may contribute to these important biological processes.
categoryCompare, an analytical tool based on feature annotations.
Sex, Specimen part, Time
View SamplesMethanol (MeOH) is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of MeOH into toxic formaldehyde (FA). Our recent genome-wide analysis of the mouse brain demonstrated that an increase in endogenous MeOH after ADH inhibition led to a significant increase in the plasma MeOH concentration and the modification of mRNA synthesis. These findings suggest endogenous MeOH involvement in homeostasis regulation by controlling mRNA levels. Here, we demonstrate directly that study volunteers displayed increasing concentrations of MeOH and FA in their blood plasma when consuming citrus pectin, ethanol and red wine. A microarray analysis of white blood cells (WBC) in volunteers after pectin intake showed various responses for 30 differentially regulated mRNAs. Most of the mRNAs were somehow involved in the pathogenesis of Alzheimer's disease (AD). There was also a decreased synthesis of hemoglobin mRNA, HBA and HBB, the presence of which in WBC RNA was not a result of red blood cells contamination because erythrocyte-specific marker genes did not show significant change. A qRT-PCR analysis of volunteer WBC after pectin and red wine intake confirmed the complicated dependence between plasma MeOH content and the mRNA accumulation of previously identified genes, namely GAPDH and SNX27, and MME, SORL1, DDIT4, HBA and HBB genes revealed in this study. We hypothesized that human plasma MeOH, which is replenished from endogenous and exogenous sources (diet), has an impact on the WBC mRNA levels of genes involved in AD pathogenesis and signaling.
Dietary methanol regulates human gene activity.
Specimen part, Subject
View SamplesMethanol (MeOH) is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of MeOH into toxic formaldehyde (FA). Our recent genome-wide analysis of the mouse brain demonstrated that an increase in endogenous MeOH after ADH inhibition led to a significant increase in the plasma MeOH concentration and the modification of mRNA synthesis. These findings suggest endogenous MeOH involvement in homeostasis regulation by controlling mRNA levels. Here, we demonstrate directly that study volunteers displayed increasing concentrations of MeOH and FA in their blood plasma when consuming citrus pectin, ethanol and red wine. A microarray analysis of white blood cells (WBC) in volunteers after pectin intake showed various responses for 30 differentially regulated mRNAs. Most of the mRNAs were somehow involved in the pathogenesis of Alzheimer's disease (AD). There was also a decreased synthesis of hemoglobin mRNA, HBA and HBB, the presence of which in WBC RNA was not a result of red blood cells contamination because erythrocyte-specific marker genes did not show significant change. A qRT-PCR analysis of volunteer WBC after pectin and red wine intake confirmed the complicated dependence between plasma MeOH content and the mRNA accumulation of previously identified genes, namely GAPDH and SNX27, and MME, SORL1, DDIT4, HBA and HBB genes revealed in this study. We hypothesized that human plasma MeOH, which is replenished from endogenous and exogenous sources (diet), has an impact on the WBC mRNA levels of genes involved in AD pathogenesis and signaling.
Dietary methanol regulates human gene activity.
Sex, Age, Specimen part, Subject
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