The gene expression analysis of the spinal cord and skeletal muscle of SBMA (Spinal Bulbar Muscular Atrophy) model mice with or without pioglitazone (PG) treatment
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ABSTRACT: To identify the gene expression changes by administering PG to SBMA model mice, we prepared total RNA samples from the spinal cords and skeletal muscles of transgenic mice carrying a full-length human AR with 97 CAGs (AR-97Q) that were treated with or without PG. We used AR-97Q (Line #7-8) male mice because they show progressive muscular atrophy and weakness as well as SBMA-like pathology such as the accumulation of the pathogenic androgen receptor in the nucleus of motor neurons. Using microarray analysis, we identified the genes with significantly altered expression of AR-97Q mice by PG treatment. For non-treated and PG-treated groups, we examined the male mice at 13 weeks of age. RNA from the total spinal cord and skeletal muscle was isolated from three mice of each group.
Project description:To identify the gene expression changes by administering PG to SBMA model mice, we prepared total RNA samples from the spinal cords and skeletal muscles of transgenic mice carrying a full-length human AR with 97 CAGs (AR-97Q) that were treated with or without PG. We used AR-97Q (Line #7-8) male mice because they show progressive muscular atrophy and weakness as well as SBMA-like pathology such as the accumulation of the pathogenic androgen receptor in the nucleus of motor neurons. Using microarray analysis, we identified the genes with significantly altered expression of AR-97Q mice by PG treatment.
Project description:To identify the gene expression changes that are specific to SBMA, we prepared total mRNA samples from the spinal cords of transgenic mice carrying a full-length human AR with 97 CAGs (AR-97Q), transgenic mice bearing a wild-type allele of AR with 24 CAGs (AR-24Q), and the wild-type littermates of the AR-97Q mice (C57BL/6). We used AR-97Q (Line #7-8) male mice because they show progressive muscular atrophy and weakness as well as SBMA-like pathology such as the accumulation of the pathogenic androgen receptor in the nucleus of motor neurons. Using microarray analysis, we identified the genes with significantly altered expression among the three types of mice.
Project description:To identify the gene expression changes that are specific to SBMA, we prepared total mRNA samples from the spinal cords of transgenic mice carrying a full-length human AR with 97 CAGs (AR-97Q), transgenic mice bearing a wild-type allele of AR with 24 CAGs (AR-24Q), and the wild-type littermates of the AR-97Q mice (C57BL/6). We used AR-97Q (Line #7-8) male mice because they show progressive muscular atrophy and weakness as well as SBMA-like pathology such as the accumulation of the pathogenic androgen receptor in the nucleus of motor neurons. Using microarray analysis, we identified the genes with significantly altered expression among the three types of mice. For each group, we examined the male mice at 7-9, 10-12, and 13-15 weeks of age. These stages were chosen because the AR-97Q mice are generally asymptomatic at 7-9 weeks of age (before-onset stage), present with mild motor impairment at 10-12 weeks (early stage), and are severely weakened with profound muscle atrophy at 13-15 weeks (advanced stage). RNA from the total spinal cord, excluding the dorsal root ganglia, was isolated from three mice of each genotype at each stage. For wild-type, pooled sample for three mice were used in each stage.
Project description:To understand the early pathogenesis of SBMA and to systematically assess the role of different cells in the spinal cord of SBMA, we conducted snRNA-seq on the spinal cord of AR-97Q and AR-24Q mice at 6 weeks. The genes related to ion channel and synapse function were up-regulated in oligodendrocytes of AR-97Q mice.
Project description:X-linked Spinal and Bulbar Muscular Atrophy (SBMA) is a rare, late-onset neuromuscular disease caused by a CAG repeat expansion mutation in the androgen receptor (AR) gene. SBMA is characterized by progressive muscle atrophy of both neurogenic and myopathic etiologies. Previous work has established that mutant AR expression in skeletal muscle could be a significant contributor to neuromuscular decline, yet the mechanisms involved remain ill-defined. As AR is a nuclear hormone receptor transcription factor, we sought to define early changes in gene expression in skeletal muscle of pre-symptomatic SBMA mice, with a focus on transcriptional changes at the neuromuscular junction (NMJ). We describe loss of key NMJ-specific genes in synaptic muscle regions of pre-symptomatic SBMA mice, while extrasynaptic muscle features a coordinated loss of sarcomere genes that coincides with ectopic re-expression of certain NMJ genes. Furthermore, SBMA muscle prominently features dysregulated calcium flux, likely stemming from a compensatory response to early atrophy that greatly exacerbates over time. The SERCA activator CDN1163 conferred a mild rescue in function and muscle size in SBMA mice, while genetic deletion of the gene encoding Myf6/MRF4, a negative regulator of sarcomere gene expression and predicted AR interactor, did not ameliorate muscle atrophy. These studies suggest that modulation of calcium flux could be a promising pharmacological target in SBMA.
Project description:To understand the early pathogenesis of SBMA and to systematically assess the role of different cells in the spinal cord of SBMA, we conducted snRNA-seq on the spinal cord of AR-97Q mice at different stages of the disease. The genes related to ion channel and synapse function were up-regulated in oligodendrocytes in early stages of SBMA although they were down-regulated at the advanced stage.
Project description:Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy’s Disease, is a slowly progressive adult-onset neuromuscular disease which results from a polyglutamine (polyQ) encoding CAG repeat expansion within the androgen receptor gene (AR). Despite the ubiquitous expression of the androgen receptor, it is unclear why motor neurons selectively degenerate and there are no effective treatments or disease modifying therapies for this debilitating disease. In order to identify potential therapeutic targets, we set out to establish the genes and molecular pathways involved in early motor neuron dysfunction in SBMA. We therefore undertook global transcriptomic profiling of cultured primary embryonic motor neurons from the spinal cord of AR100 mice, which model SBMA.. Four biological replicate samples were used for genome wide analysis using Affymetrix 430 v2.0 mouse arrays. Data was normalised using therobust multichip average (RMA) algorithm.
Project description:Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disorder caused by a polyglutamine expansion in the androgen receptor (AR). Previous studies have shown that transcriptional dysregulation and mitochondrial impairment occur in SBMA. We used gene-expression analysis and ChIP-sequencing to map transcriptional changes in SBMA induced pluripotent stem cell-derived motor neurons. The SBMA cells had decreased expression of genes encoding electron transport chain subunits and other metabolic proteins, associated with reduced histone acetylation which may be contributing to mitochondrial dysfunction. AR ChIP-sequencing results indicate that this is not a direct transcriptional effect of mutant AR on mitochondrial gene expression. Furthermore, we found decreased acetyl-CoA, and pyruvate supplementation to correct this deficiency improved mitochondrial function and SBMA motor neuron viability. We propose that epigenetic dysregulation of metabolic genes contributes to reduced mitochondrial ATP production. Our results show a molecular link between altered epigenetic regulation and mitochondrial metabolism that contributes to neurodegeneration.
Project description:Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disorder caused by a polyglutamine expansion in the androgen receptor (AR). Previous studies have shown that transcriptional dysregulation and mitochondrial impairment occur in SBMA. We used gene-expression analysis and ChIP-sequencing to map transcriptional changes in SBMA induced pluripotent stem cell-derived motor neurons. The SBMA cells had decreased expression of genes encoding electron transport chain subunits and other metabolic proteins, associated with reduced histone acetylation which may be contributing to mitochondrial dysfunction. AR ChIP-sequencing results indicate that this is not a direct transcriptional effect of mutant AR on mitochondrial gene expression. Furthermore, we found decreased acetyl-CoA, and pyruvate supplementation to correct this deficiency improved mitochondrial function and SBMA motor neuron viability. We propose that epigenetic dysregulation of metabolic genes contributes to reduced mitochondrial ATP production. Our results show a molecular link between altered epigenetic regulation and mitochondrial metabolism that contributes to neurodegeneration.
Project description:Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disorder caused by a polyglutamine expansion in the androgen receptor (AR). Previous studies have shown that transcriptional dysregulation and mitochondrial impairment occur in SBMA. We used gene-expression analysis and ChIP-sequencing to map transcriptional changes in SBMA induced pluripotent stem cell-derived motor neurons. The SBMA cells had decreased expression of genes encoding electron transport chain subunits and other metabolic proteins, associated with reduced histone acetylation which may be contributing to mitochondrial dysfunction. AR ChIP-sequencing results indicate that this is not a direct transcriptional effect of mutant AR on mitochondrial gene expression. Furthermore, we found decreased acetyl-CoA, and pyruvate supplementation to correct this deficiency improved mitochondrial function and SBMA motor neuron viability. We propose that epigenetic dysregulation of metabolic genes contributes to reduced mitochondrial ATP production. Our results show a molecular link between altered epigenetic regulation and mitochondrial metabolism that contributes to neurodegeneration.