Similar Datasets
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.
2020-08-10 | GSE140016 | GEO
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.
2020-08-10 | GSE140015 | GEO
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.
2020-08-10 | GSE140017 | GEO
Project description:Mechanism of Mitochondrial Dysfunction in Spinal and Bulbar Muscular Atrophy
| PRJNA588038 | ENA
Project description:Spinal and bulbar muscular atrophy (SBMA) is a motor neuron disease caused by polyglutamine expansion mutation in the androgen receptor (AR). We investigated whether the mutant protein alters mitochondrial function. We found that constitutive and doxycycline-induced expression of the mutant AR in MN-1 and PC12 cells, respectively, are associated with depolarization of the mitochondrial membrane. This was mitigated by cyclosporine A, which inhibits opening of the mitochondrial permeability transition pore. We also found that the expression of the mutant protein in the presence of ligand results in an elevated level of reactive oxygen species, which is blocked by the treatment with the antioxidants co-enzyme Q10 and idebenone. The mutant protein in MN-1 cells also resulted in increased Bax, caspase 9 and caspase 3. We assessed the effects of mutant AR on the transcription of mitochondrial proteins and found altered expression of the peroxisome proliferator-activated receptor gamma coactivator 1 and the mitochondrial specific antioxidant superoxide dismutase-2 in affected tissues of SBMA knock-in mice. In addition, we found that the AR associates with mitochondria in cultured cells. This study thus provides evidence for mitochondrial dysfunction in SBMA cell and animal models, either through indirect effects on the transcription of nuclear-encoded mitochondrial genes or through direct effects of the mutant protein on mitochondria or both. These findings indicate possible benefit from mitochondrial therapy for SBMA.
| S-EPMC2644643 | biostudies-literature
Project description:Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder caused by recessive mutations in the SMN1 gene, globally affecting ~8-14 newborns per 100,000. The severity of the disease depends on the residual levels of functional survival of motor neuron protein, SMN. SMN is a ubiquitously expressed RNA binding protein involved in a plethora of cellular processes. In this review, we discuss the effects of SMN loss on mitochondrial functions in the neuronal and muscular systems that are the most affected in patients with spinal muscular atrophy. Our aim is to highlight how mitochondrial defects may contribute to disease progression and how restoring mitochondrial functionality may be a promising approach to develop new therapies. We also collected from previous studies a list of transcripts encoding mitochondrial proteins affected in various SMA models. Moreover, we speculate that in adulthood, when motor neurons require only very low SMN levels, the natural deterioration of mitochondria associated with aging may be a crucial triggering factor for adult spinal muscular atrophy, and this requires particular attention for therapeutic strategies.
| S-EPMC9503857 | biostudies-literature
Project description:Spinal and bulbar muscular atrophy is an X-linked neuromuscular disease caused by an expanded repeat in the androgen receptor gene. The mutant protein is toxic to motor neurons and muscle. The toxicity is ligand-dependent and likely involves aberrant interaction of the mutant androgen receptor with other nuclear factors leading to transcriptional dysregulation. Various therapeutic strategies have been effective in transgenic animal models, and the challenge now is to translate these strategies into safe and effective treatment in patients.
| S-EPMC5094812 | biostudies-literature
Project description:Mechanism of Mitochondrial Dysfunction in Spinal and Bulbar Muscular Atrophy [RNA-seq]
| PRJNA588040 | ENA
Project description:Mechanism of Mitochondrial Dysfunction in Spinal and Bulbar Muscular Atrophy [ChIP-seq]
| PRJNA588042 | ENA
Project description:The survival motor neuron 1 (SMN1) gene is the causative gene for the spinal muscular atrophy (SMA) disease, the first genetic cause of infant mortality. It affects primarily motor neurons which are the targets of the approved genetic therapies aimed to compensate for the loss of SMN1. However, the limitations of these therapies are now evident since they are not cures, and alternative strategies need to be investigated. Because of the ubiquitous and multifunctional roles of SMN1 in the cell, deeper understanding of the molecular mechanisms underlying intrinsic abnormalities of the different tissues affected by SMA is crucial for the development of new therapeutic approaches. Here we used a muscle specific genetic mouse model for the identification of key cellular processes associated to SMN1 loss, at single myofiber level. We found that mitochondrial dysfunction is a key pathogenetic event in SMA: mitochondria are abnormal with internal degenerated cristae. The ultrastructural changes are coincident with alterations in ROS levels by monoamine oxidase A and Ca2+ homeostasis. Interestingly, the improvements of the myopathic phenotype of the muscle-specific SMA model mice by transplantation of amniotic fluid stem (AFS) cells led to restore mitochondrial function. Our data suggest that a mitochondria-targeting therapy may represent a complementary and broad treatment strategy to further optimize the current treatment.
2023-03-08 | GSE207890 | GEO