Modulation of histone H3K4 dimethylation by spermidine ameliorates motor neuron survival and neuropathology in a mouse model of ALS
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ABSTRACT: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive paralysis due to motor neuron degeneration. It has been proposed that epigenetic modification and transcriptional dysregulation may contribute to motor neuron death. In this study, we investigate the basis for therapeutic approaches to target lysine-specific histone demethylase 1 (LSD1) and elucidate the mechanistic role of LSD1-histone H3K4 signaling pathway in ALS pathogenesis. Cellular and animal models of ALS were treated by spermidine (SD), then we performed neuropathological, body weight and survival evaluation in order to examine the role of SD in mutant superoxide dismutase 1 (mSOD1) (G93A) ALS mice. Herein, we found that dimethylated histone H3K4 (H3K4me2) levels are decreased in cellular and animal models of ALS, and correlated with motor neuronal dysfunction in ALS (G93A) mice. SD administration modulated the LSD1 activity and restored H3K4me2 levels in ChAT-positive motor neurons in the lumbar spinal cord of ALS mice. SD prevented cellular damage by improving the number and size of motor neurons in ALS mice. SD administration also reduced GFAP-positive astrogliogenesis in the white and gray matter of the lumbar spinal cord, improving the neuropathology of ALS mice. Moreover, SD administration delayed disease onset and prolonged the lifespan of ALS (G93A) transgenic mice. Together, modulating epigenetic targets such as LSD1 by small compounds may be a useful therapeutic strategy for treating ALS.
Project description:Microarray analysis has been applied to the study of ALS in order to investigate gene expression in whole spinal cord homogenates of SOD1 G93A mice and human ALS cases, although the massive presence of glial cells and inflammatory factors has made it difficult to define which gene expression changes were motor neuron specific. Recently, laser capture microdissection (LCM), combined with microarray analysis, has allowed the identification of motor neuron specific changes in gene expression in human ALS cases. The aim of the present study is to combine LCM and microarray analysis to study how motor neurons in the spinal cord of transgenic SOD1 G93A mice and transgenic SOD1 WT respond to stimuli determined by the presence of the human mutant protein throughout the evolution of the stages in motor neuron injury Experiment Overall Design: Motor neurons have been isolated from the spinal cord of G93A mice and non transgenic littermates at different time points and the transcription expression profile of the isolated motor neurons has been analysed
Project description:Microarray analysis has been applied to the study of ALS in order to investigate gene expression in whole spinal cord homogenates of SOD1 G93A mice and human ALS cases, although the massive presence of glial cells and inflammatory factors has made it difficult to define which gene expression changes were motor neuron specific. Recently, laser capture microdissection (LCM), combined with microarray analysis, has allowed the identification of motor neuron specific changes in gene expression in human ALS cases. The aim of the present study is to combine LCM and microarray analysis to study how motor neurons in the spinal cord of transgenic SOD1 G93A mice and transgenic SOD1 WT respond to stimuli determined by the presence of the human mutant protein throughout the evolution of the stages in motor neuron injury Keywords: Murine motor neurons
Project description:To investigate the role of motor neuron autophagy in ALS, we generated mice in which the critical autophagy gene Atg7 was specifically disrupted in motor neurons (Atg7 cKO). We also bred these mice to the SOD1G93A mouse model of ALS. Then we performed RNA sequencing on lumbar spinal cords from these mice to determine how motor neuron autophagy inhibition altered gene expression.
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:The transgenic mice expressing the human mutated form (G93A) of the SOD1 gene represent a valuable model of Amyotrophic Lateral Sclerosis (ALS). SOD1 is one of the main causative genes of familial ALS which accounts for 10% of cases. These transgenic animals develop a motorneuronal pathology that recapitulates well the neuropathological features occuring in ALS patients, and the progression of the disease can be monitored by a series of motor tests. Gastrocnemius is the first and most affected muscle in the disease, while triceps is relatively spared. Gene expression data of degenerating motor neurons at different disease stages are already available, while gene expression data on the muscle tissue are missing. Our aim is to define the role of muscle in motor neuron degeneration in ALS. Keywords: Single stage analysis (presymptomatic stage, 7 week-old mice) We considered two sets of muscle at presymptomatic stage (7 weeks): gastrocnemius and triceps from 4 transgenic SOD1G93A and 4 non-transgenic mice (NTg).
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:Gene expression changes in spinal motor neurons of the SOD1G93A-transgenic model for ALS after treatment with G-CSF. To gain insight into the mode of action of G-CSF, we performed gene expression profiling on isolated lumbar motor neurons from SOD1G93A mice, the most frequently studied animal model for ALS, with and without G-CSF treatment.
Project description:Microarray analysis has been applied to the study of ALS in order to investigate gene expression in whole spinal cord homogenates of SOD1 G93A mice and human ALS cases, although the massive presence of glial cells and inflammatory factors has made it difficult to define which gene expression changes were motor neuron specific. Recently, laser capture microdissection (LCM), combined with microarray analysis, has allowed the identification of motor neuron specific changes in gene expression in mouse and human ALS cases. The aim of the present study is to combine LCM and microarray analysis to compare the gene expression profiles of motor neurons from two SOD1G93A mouse strains (129Sv and C57) with different progression of the disease in order to discover the molecular mechanisms that may contribute to the distinct phenotypes and to uncover factors underlying fast and slow disease progression Motor neurons have been isolated from the spinal cord of 129SvG93A mice, C57G93A mice and non transgenic littermates at different time points and the transcription expression profile of the isolated motor neurons has been analysed
Project description:The transgenic mice expressing the human mutated form (G93A) of the SOD1 gene represent a valuable model of Amyotrophic Lateral Sclerosis (ALS). SOD1 is one of the main causative genes of familial ALS which accounts for 10% of cases. These transgenic animals develop a motorneuronal pathology that recapitulates well the neuropatological features occuring in ALS patients, and the progression of the disease can be monitored by a series of motor tests. Gastrocnemius is first and most affected muscle in the disease, while triceps is relatively spared. Gene expression data of degenerating motor neurons at different disease stages are already available, while gene expression data on the muscle tissue are missing. Our aim is to define the role of muscle in motor neuron degeneration in ALS. Keywords: Single stage analysis (early symptomatic stage, 14 weeks-old mice) We considered two sets of muscle at symptomatic stage (14 weeks): gastrocnemius and triceps from 4 transgenic SOD1G93A and 4 non-transgenic mice (NTg). Gastrocnemius from 4 nerve-crushed mice were also considered as controls for the denervation process
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.