Project description:Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease whose pathophysiology is largely unknown. Despite motor neuron death is recognized as the key event in ALS, astrocytes dysfunctionalities and neuroinflammation were demonstrated to accompany and probably even drive motor neuron loss. Nevertheless, the mechanisms priming astrocyte failure and hyperactivation are still obscure. In this work, altered pathways in ALS astrocytes were unveiled by investigating the proteomic profile of primary spinal-cord astrocytes derived from transgenic ALS mouse model overexpressing the human (h)SOD1(G93A) protein, in comparison with the transgenic counterpart expressing hSOD1(WT) protein. In this research, we showed that hSOD1(G93A) astrocytes present a profound alterations in the expression of proteins involved in proteostasis and glutathione metabolism.
Project description:This datased was used to obtain a genome-wide expression signature for the early response of mouse motor neurons to mutant SOD1 astrocytes conditioned media. Neurons, far from living in isolation, are surrounded by a host of other neuronal and non-neuronal cells, such as astrocytes. The latter entertain complex functional interactions with neighboring neurons, which, under normal conditions, are important for the their well-being. In pathological situations, however, altered astrocyte behavior may contribute to the demise of neighboring neurons. Such non-cell autonomous pathogenic scenario is increasingly considered in a variety of disorders, including amyotrophic lateral sclerosis (ALS), the most frequent adult-onset paralytic disorder. Assembly and interrogation of gene regulatory models has helped elucidate causal mechanisms responsible for the presentation of several tumor-related phenotypes. To systematically elucidate the effectors of neurodegeneration in a model of ALS, we first developed techniques for the efficient purification of motor neurons (MNs), the primary target of ALS neurodegenerative process. We then generated gene expression profiles to fully characterize the critical timepoints associated with initiation and commitment of MN degenerative progression in an in vitro murine mutant SOD1 (mSOD1) model of ALS. ES cells were derived from transgenic Hlxb9-GFP1Tmj mice expressing eGFP and CD2 driven by the mouse HB9 promoter. These cells were then differentiated into motor neurons (ES-MN) as described previously [PMID 12176325] ES-MN were exposed to non-transgenic (NTg), G93A mutant SOD1 (mSOD1) or wtSOD1 over-expression astrocytes conditioned media for 0 days (time zero control), 1 day, and 3 days. Total RNA was extracted and profiled by RNAseq.
Project description:Amyotrophic Lateral Sclerosis (ALS) is generally a late onset neurodegenerative disease. Mutations in the Cu/Zn superoxide dismutase 1 (SOD1) gene accounts for approximately 20% of familial ALS and 2% of all ALS cases. Although a number of hypothesis have been proposed to explain mutant SOD1 toxicity, the molecular mechanisms of the disease remain unclear. SOD1 linked ALS is thought to function in a non-cell autonomous manner such that the motoneurons are critical for the onset and glia contribute to the progress of the disease. To dissect the roles of motoneurons and glia, we used the Gal4-UAS system to determine gene expression changes following the expression of mutant human SOD1 (G85R) selectively in either motoneurons or glia, and concurrently in motoneurons and glia of flies. We conducted a microarray on young (5 days old) and old (45 days old) flies expressing G85R in these cell types and identified a number of genes involved in a variety of processes. The candidate genes identified by this screen may help elucidate the individual and combined contributions of motoneurons and glial cells in ALS. We used microarrays to evaluate the transcriptional profile of 5 day old and 45 day old flies expressing mutant human SOD1 (G85R) in a tissue specific manner in motoneurons, glia, and together in motoneurons and glia and compared the expression to flies expressing wild-type drosophila SOD1 controls.
Project description:Amyotrophic lateral sclerosis (ALS) is caused by the progressive degeneration of motor neurons. Mutations in the Cu/Zn superoxide dismutase (SOD1) are found in about 20% of patients with familial ALS. Mutant SOD1 causes motor neuron death through an acquired toxic property. Although, molecular mechanism underlying this toxic gain-of-function remains unknown, evidence support the role of mutant SOD1 expression in non-neuronal cells in shaping motor neuron degeneration. We have previously found that in contrast to non-transgenic, SOD1G93A-expressing astrocytes induced apoptosis of co-cultured motor neurons. This prompted us to investigate whether the effect on motor neuron survival was related to a change in the gene expression profile. Through high-density oligonucletide microarrays we found changes in the expression of genes involved in transcription, signaling, cell proliferation, extracellular matrix construction, response to stress and steroid and lipid metabolism. Decorin, a small multifunctional proteoglycan, was the most up-regulated gene. Down-regulated genes included the insulin-like growth factor-1 receptor and the RNA binding protein ROD1. We also analyzed the expression of selected genes in purified motor neurons expressing SOD1G93A and in spinal cord of asymptomatic and early symptomatic ALS-rodent model. The expression of mutated SOD1 in astrocytes cause gene expression changes with potential consequences for its interaction with motor neurons. The astrocyte-specific gene expression profile contributes to the identification of possible candidates for cell type-specific therapies in ALS Keywords: Cell type comparison
Project description:Amyotrophic Lateral Sclerosis (ALS) is generally a late onset neurodegenerative disease. Mutations in the Cu/Zn superoxide dismutase 1 (SOD1) gene accounts for approximately 20% of familial ALS and 2% of all ALS cases. Although a number of hypothesis have been proposed to explain mutant SOD1 toxicity, the molecular mechanisms of the disease remain unclear. SOD1 linked ALS is thought to function in a non-cell autonomous manner such that the motoneurons are critical for the onset and glia contribute to the progress of the disease. To dissect the roles of motoneurons and glia, we used the Gal4-UAS system to determine gene expression changes following the expression of mutant human SOD1 (G85R) selectively in either motoneurons or glia, and concurrently in motoneurons and glia of flies. We conducted a microarray on young (5 days old) and old (45 days old) flies expressing G85R in these cell types and identified a number of genes involved in a variety of processes. The candidate genes identified by this screen may help elucidate the individual and combined contributions of motoneurons and glial cells in ALS. We used microarrays to evaluate the transcriptional profile of 5 day old and 45 day old flies expressing mutant human SOD1 (G85R) in a tissue specific manner in motoneurons, glia, and together in motoneurons and glia and compared the expression to flies expressing wild-type drosophila SOD1 controls. The Gal4-UAS system was used to drive tissue expression of either mutant human SOD1 (G85R) or wild-type drosophila SOD1 (dSOD1) in flies. Flies containing either the motoneuronal driver, D42-Gal4, the glial driver, M1B-Gal4, or the combined motoneuronal and glial drivers, D42+M1B-Gal4 were crossed to flies containing either mutant human SOD1, UAS-G85R, or wild-type drosophila SOD1, UAS-dSOD1, as a control. Adult male progeny were collected within 24 hours after eclosion and aged to 5 (5d) and 45 (45d) days old. Groups of 10 flies were maintained in vials of cornmeal agar food and transferred to fresh food every 5-7 days. For each Gal4-UAS line and each age, 3 biological replicates consisting of 40 whole flies were flash frozen in liquid nitrogen and used to isolate total RNA, for a total of 36 samples.
Project description:Amyotrophic lateral sclerosis (ALS) is caused by the progressive degeneration of motor neurons. Mutations in the Cu/Zn superoxide dismutase (SOD1) are found in about 20% of patients with familial ALS. Mutant SOD1 causes motor neuron death through an acquired toxic property. Although, molecular mechanism underlying this toxic gain-of-function remains unknown, evidence support the role of mutant SOD1 expression in non-neuronal cells in shaping motor neuron degeneration. We have previously found that in contrast to non-transgenic, SOD1G93A-expressing astrocytes induced apoptosis of co-cultured motor neurons. This prompted us to investigate whether the effect on motor neuron survival was related to a change in the gene expression profile. Through high-density oligonucletide microarrays we found changes in the expression of genes involved in transcription, signaling, cell proliferation, extracellular matrix construction, response to stress and steroid and lipid metabolism. Decorin, a small multifunctional proteoglycan, was the most up-regulated gene. Down-regulated genes included the insulin-like growth factor-1 receptor and the RNA binding protein ROD1. We also analyzed the expression of selected genes in purified motor neurons expressing SOD1G93A and in spinal cord of asymptomatic and early symptomatic ALS-rodent model. The expression of mutated SOD1 in astrocytes cause gene expression changes with potential consequences for its interaction with motor neurons. The astrocyte-specific gene expression profile contributes to the identification of possible candidates for cell type-specific therapies in ALS Keywords: Cell type comparison Astrocytes were plated at a density of 2x104 cells/cm2 and maintained as described in Cassina P, et al.J Neurosci Res. 2002;67(1):21-9. Confluent astrocytes monolayers were changed to supplemented L15 medium (Vargas et al., 2006) for 24h before RNA isolation. Total RNA was isolated with RNeasy kit/RNase-Free DNase Set (Qiagen, CA, USA). RNA quality was assessed with the A260/280 ratio and the 2100 Bioanalyzer (Agilent Technologies, CA, USA) to ensure integrity of the samples used for microarray analysis. Double-stranded cDNA was synthesized from 5 μg of total RNA and used for microarray analysis with the Rat Genome 230 2.0 array (Affymetrix, CA, USA). A total of six arrays divided in three control and three transgenic samples were used. Labeling was performed with one-cycle target labeling assay according to Affymetrix, including the eukaryotic poly-A RNA control and the eukaryotic hybridization control kit. Hybridization, washing and scanning were carried out as described in the Affymetrix GeneChip expression analysis technical manual at the Oregon State University’s Center for Genome Research and Biocomputing. Image processing was done using Affymetrix GCOS 1.4 software. The quality of hybridization and overall chip performance was determined by visual inspection of the raw scanned data and the GCOS-generated report file. Microarray data (.CEL files) was normalized using GC-RMA probe-level analysis in ArrayAssist 4.0 (Stratagene, CA, USA). Following variance stabilization and Log transformation, fold chance versus p-value was calculated using nontransgenic (NonTG) samples as base values.
Project description:This datased was used to obtain a genome-wide expression signature for the early response of mouse motor neurons to mutant SOD1 astrocytes conditioned media. Neurons, far from living in isolation, are surrounded by a host of other neuronal and non-neuronal cells, such as astrocytes. The latter entertain complex functional interactions with neighboring neurons, which, under normal conditions, are important for the their well-being. In pathological situations, however, altered astrocyte behavior may contribute to the demise of neighboring neurons. Such non-cell autonomous pathogenic scenario is increasingly considered in a variety of disorders, including amyotrophic lateral sclerosis (ALS), the most frequent adult-onset paralytic disorder. Assembly and interrogation of gene regulatory models has helped elucidate causal mechanisms responsible for the presentation of several tumor-related phenotypes. To systematically elucidate the effectors of neurodegeneration in a model of ALS, we first developed techniques for the efficient purification of motor neurons (MNs), the primary target of ALS neurodegenerative process. We then generated gene expression profiles to fully characterize the critical timepoints associated with initiation and commitment of MN degenerative progression in an in vitro murine mutant SOD1 (mSOD1) model of ALS.
Project description:Recent genetic studies of ALS patients have identified several forms of ALS that are associated with mutations in RNA binding proteins. In animals or cultured cells, such defects broadly affect RNA metabolism. This raises the question of whether all forms of ALS have general effects on RNA metabolism. We tested this hypothesis in a mouse model of ALS that is transgenic for a human disease-causing mutation in the enzyme superoxide dismutase 1 (SOD1). We analyzed RNA from laser-captured spinal cord motor neuron cell bodies of the mutant SOD1 strain, comparing the RNA profile with that from a corresponding wild-type SOD1 transgenic strain. We prepared the samples from animals that were presymptomatic, but which manifested abnormalities at the cellular level that are seen in ALS, including aggregation of the mutant protein in motor neuron cell bodies and defective morphology of neuromuscular junctions, the connections between neuron and muscle. We observed only minor changes in the level and splicing of RNA in the SOD1 mutant animals as compared with wild-type, suggesting that mutant SOD1 produces the toxic effects of ALS by a mechanism that does not involve global RNA disturbance. RNA-Seq of laser microdissection of motor neuron bodies from two biological replicates each of SOD1 YFP (wildtype 592) and SOD1 G85R YFP (737) transgenic mice.
Project description:In familial forms of amyotrophic lateral sclerosis (ALS) caused by mutations in superoxide dismutase-1 (SOD1) gene, both cell-autonomous and non-cell-autonomous mechanisms lead to the selective degeneration of motoneurons. Gene-targeted deletion of mutated SOD1 in mature astrocytes has been shown to slow down disease progression. However, the potential therapeutic application of targeting astrocytes has not been evaluated yet. Here, an AAV vector encoding an artificial microRNA is used to deliver RNA interference against mutated SOD1 by targeting astrocytes in ALS mice. In mice expressing the mutated SOD1G93A protein, we found that the treatment leads to the progressive rescue of neuromuscular junction occupancy, to the recovery of the compound muscle action potential in the gastrocnemius muscle, and significantly improves neuromuscular function. In the spinal cord, gene therapy targeting astrocytes protects a small pool of fast-fatigable motoneurons until disease end stage. In the gastrocnemius muscle of the treated SOD1G93A mice, the fast-twitch type IIb muscle fibers are preserved from atrophy. Axon collateral sprouting is observed together with muscle fiber type grouping indicative of denervation/re-innervation events. The transcriptome profiling of spinal cord motoneurons shows changes in the expression levels of factors regulating the dynamics of microtubules. Gene therapy delivering RNA interference against mutated SOD1 in astrocytes provides therapeutic effects enhancing motoneuron plasticity and improving neuromuscular function in ALS mice.