Project description:Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease that progressively debilitates neuronal cells that control voluntary muscle activity. In a mouse model of ALS that expresses mutated human superoxide dismutase 1 (SOD1-G93A) skeletal muscle is one of the tissues affected early by mutant SOD1 toxicity. Fast-twitch and slow-twitch muscles are differentially affected in ALS patients and in the SOD1-G93A model, fast-twitch muscles being more vulnerable. We used miRNA microarrays to investigate miRNA alterations in fast-twitch (EDL) and slow-twitch (soleus) skeletal muscles of symptomatic SOD1-G93A animals and their age-matched wild type littermates.
Project description:Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease that progressively debilitates neuronal cells that control voluntary muscle activity. In a mouse model of ALS that expresses mutated human superoxide dismutase 1 (SOD1-G93A) skeletal muscle is one of the tissues affected early by mutant SOD1 toxicity. Fast-twitch and slow-twitch muscles are differentially affected in ALS patients and in the SOD1-G93A model, fast-twitch muscles being more vulnerable. We used miRNA microarrays to investigate miRNA alterations in fast-twitch (EDL) and slow-twitch (soleus) skeletal muscles of symptomatic SOD1-G93A animals and their age-matched wild type littermates. At age of 90 days RNA was extracted from extensor digitorum longus (EDL) and soleus (SOL) muscles of male SOD1-G93A animals and their age-matched wild type male littermates. RNA was hybridized on Affymetrix Multispecies miRNA-2_0 Array.
Project description:To investigate the usefulness of gene expression as diagnostic biomarkers, we compared whole genome expression profiles of lumbar spinal cord with profiles of peripheral blood and tibialis anterior muscle in 16 mutant G93A-SOD1 mice and 15 wild type littermates. Total RNA obtained from blood, tibialis anterior muscle and lumbar spinal cord of G93A-SOD1 mice compared to wild type littermates.
Project description:To investigate the usefulness of gene expression as diagnostic biomarkers, we compared whole genome expression profiles of lumbar spinal cord with profiles of peripheral blood and tibialis anterior muscle in 16 mutant G93A-SOD1 mice and 15 wild type littermates.
Project description:mRNA expression in the spinal cords of the G93A-SOD1 familial ALS transgenic mouse model was compared to that in nontransgenic (Normal mouse) and transgenic mice expressing wild-type (WT)SOD1. Gene Ontology (GO)analysis was used to characterize differences in expression between G93A-SOD1 mouse and nontransgenic mouse spinal cord. Changes in multiple GO categories were found. Many of these were associated with subsystems involving cell-cell communication and intracellular signal transduction. Expression profiles of mice expressing WT-SOD1 did not differ from nontransgenic mice. In contrast, protein profiling using proteomics technology indicated changes in mitochondrial protein expression in the G93A-SOD1 mouse spinal cord that were not found in the mRNA expression analysis. Keywords: Disease state analysis, time course, transgenic mice
Project description:Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by the selective loss of motor neurons. While the contribution of peripheral organs remains incompletely understood, recent evidence suggests that brown adipose tissue (BAT) and its secreted extracellular vesicles (EVs) could play a role in diseased context as ALS. In this study, we employed a multi-omics approach, including RNA sequencing and proteomics, to investigate the alterations in BAT and its EVs in the SOD1-G93A mouse model of ALS. Our results revealed significant changes in the proteomic and transcriptomic profiles of BAT from SOD1-G93A mice, highlighting ALS-related features such as mitochondrial dysfunction and impaired differentiation capacity. Specifically, primary brown adipocytes (PBAs) from SOD1-G93A mice exhibited differentiation impairment, respiratory defects, and alterations in mitochondrial dynamics. Furthermore, the BAT-derived EVs from SOD1-G93A mice displayed distinct changes in size distribution and cargo content, which negatively impacted the differentiation and homeostasis of C2C12 murine myoblasts, as well as induced atrophy in C2C12-derived myotubes. These findings suggest that BAT undergoes pathological perturbations in ALS, contributing to skeletal muscle degeneration through the secretion of dysfunctional EVs. This study provides novel insights into the role of BAT in ALS pathogenesis and highlights potential therapeutic targets for mitigating muscle wasting in ALS patients.
Project description:mRNA expression in the spinal cords of the G93A-SOD1 familial ALS transgenic mouse model was compared to that in nontransgenic (Normal mouse) and transgenic mice expressing wild-type (WT)SOD1. Gene Ontology (GO)analysis was used to characterize differences in expression between G93A-SOD1 mouse and nontransgenic mouse spinal cord. Changes in multiple GO categories were found. Many of these were associated with subsystems involving cell-cell communication and intracellular signal transduction. Expression profiles of mice expressing WT-SOD1 did not differ from nontransgenic mice. In contrast, protein profiling using proteomics technology indicated changes in mitochondrial protein expression in the G93A-SOD1 mouse spinal cord that were not found in the mRNA expression analysis.
Project description:Skeletal muscle is a highly structured and differentiated tissue responsible for voluntary movement and metabolic regulation. Muscles however, are heterogeneous and depending on their location, speed of contraction, fatiguability and function, can be broadly subdivided into fast and slow twitch as well as subspecialized muscles, with each group expressing common as well as specific proteins. Congenital myopathies are a group of non-inflammatory non-dystrophic muscle diseases caused by mutations in a number of genes, leading to a weak muscle phenotype. In most cases specific muscles types are affected, with preferential involvement of fast twitch muscles as well as extraocular and facial muscles. The aim of this study is to compare the proteome of three groups of muscles from wild type and transgenic mice carrying compound heterozygous mutations in Ryr1 identified in a patient with a severe congenital myopathy. Qualitative proteomic analysis was performed by comparing the relative fold change of proteins in fast twitch and slow twitch muscles. Subsequently we compared the proteome of different muscles in wild type and Ryr1 mutant mice. Finally, we applied a quantitative analysis to determine the stoichiometry of the main protein components involved in excitation contraction coupling and calcium regulation. Our results show that recessive Ryr1 mutations do not only cause a change in RyR1 protein content in skeletal muscle, but they are accompanied by profound changes in protein expression in the different muscle types and that the latter effect may be responsible in part, for the weak muscle phenotype observed in patients.
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.
Project description:We measured gene expression differences in the extensor digitorum longus (edl) skeletal muscle between wild-type and mice lacking Cu, Zn-superoxide dismutase to determine the effect of chronic oxidative stress on skeletal muscle. We analyzed 4 edl samples from WT mice and 4 samples from the SOD1 knockouts.