Project description:Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a childhood-onset cerebellar ataxia caused by mutations in SACS, which encodes the protein sacsin. Cellular ARSACS phenotypes include mitochondrial dysfunction, intermediate filament disorganization, and the progressive death of cerebellar Purkinje neurons. It is unclear how the loss of sacsin function causes these deficits, or why they manifest as cerebellar ataxia. To investigate this, we performed multi-omic profiling of sacsin knockout cells and compared them to wild-type controls
Project description:Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is caused by mutations in SACS gene encoding sacsin. ARSACS patients and mouse models display early degeneration of cerebellum in agreement with high sacsin expression in this organ. We performed unbiased transcriptomic of cerebella from Sacs KO mice versus controls to dissect the mechanisms underlying cerebellar degeneration in ARSACS.
Project description:Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a fatal brain disorder featuring cerebellar neurodegeneration leading to spasticity and ataxia. ARSACS is caused by mutations in the SACS gene that encodes sacsin, a massive 4579 amino acid protein with multiple modular domains. Here we demonstrate that sacsin binds to microtubules and regulates microtubule dynamics. Loss of sacsin function in knockout cell lines, knockdown and knockout neurons, and patient fibroblasts leads to alterations in lysosomal transport, positioning, function and reformation following autophagy.
Project description:Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an inherited neurodegenerative disease characterized by early-onset spasticity in the lower limbs, axonal-demyelinating sensorimotor peripheral neuropathy, and cerebellar ataxia. Our understanding of the genetic basis, protein function and disease mechanisms of ARSACS have been only partially explored. The integrative use of organelle-based quantitative proteomics and whole genome analysis proposed in this study, allowed identifying affected pathways, upstream regulators, and disease and biological functions related to ARSACS, with a motivation for setting improved, early diagnostic strategies and to offer alternative treatment options in a rare condition without the cure. Our results deepen the evidence for the impairment of autophagy and mitochondrial dysfunction in SACS knockout lysosomes and mitochondrial compartment, anticipating putative candidate biomarkers related to organelle damage.
Project description:Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a childhood-onset cerebellar ataxia caused by mutations in SACS, which encodes the protein sacsin. Cellular ARSACS phenotypes include mitochondrial dysfunction, intermediate filament disorganization, and the progressive death of cerebellar Purkinje neurons. It is unclear how the loss of sacsin function causes these deficits, or why they manifest as cerebellar ataxia. Here, we performed multi-omic profiling in sacsin knockout (KO) cells, and identified alterations in microtubule dynamics, protein trafficking, and mislocalization of synaptic and focal adhesion proteins, including multiple integrins. Focal adhesion structure, signaling, and function were affected in KO cells, which could be rescued by reducing levels of PTEN, an overabundant negative regulator of focal adhesion signaling. Purkinje neurons in ARSACS mice possessed mislocalization of ITGA1, and disorganization of synaptic structures in the deep cerebellar nucleus (DCN). Interactome analysis revealed that sacsin regulates protein-protein interactions between structural and synaptic adhesion proteins. Our findings suggest that disrupted trafficking of synaptic adhesion proteins is a causal molecular deficit underlying ARSACS.
Project description:Australian working Kelpie dogs are known to be affected with an autosomal recessive form of inherited cerebellar ataxia (cerebellar abiotrophy, CA) that is characterised by a degeneration of Purkinje and granule cells in the cerebellar cortex. The clinical signs of CA include cerebellar ataxia, head tremor, motor in-coordination, wide based stance and high stepping gait, with varied clinical onset age. The clinical and pathological features are similar to cerebellar ataxias in humans. The genome-wide association study on a group of working Kelpies affected with the later onset form of CA identified a region on chromosome 9 to be strongly associated with the disease phenotype. Homozygosity analysis and whole genome sequencing identified a missense single nucleotide polymorphism, that segregated with the CA phenotype.
Project description:Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurological disease characterized by autosomal recessive mutations in the sacsin gene (SACS), that cause in patients progressive cerebellar atrophy, damage of the peripheral nerves, and significant retinal changes and cognitive impairment. No effective therapies have been proposed for ARSACS, even if some evidences suggest that powerful antioxidant agents can be considered a therapeutic tool. Resveratrol (Res) is a natural polyphenol compound derived from vegetal sources, the application of which in biomedicine is increasing in the latest years because of its significant therapeutic effects, in particular in neurodegenerative diseases. In this study, we provide evidences about its potential exploitation in the treatment of ARSACS. Because of the low solubility of resveratrol in physiological media, a nanoplatform based on nanostructured lipid carriers is here proposed for its encapsulation and delivery. Resveratrol-loaded nanostructured lipid carriers (Res-NLCs) have been synthetized, characterized, and tested on healthy and ARSACS patient fibroblasts. Nanovectors displayed optimal stability and biocompatibility, and excellent antioxidant and anti-inflammatory activities. A comprehensive investigation at gene (with real-time quantitative RT-PCR (qRT-PCR)) and protein (with proteomics) level demonstrated the therapeutic potential of Res-NLCs, encouraging future investigations on pre-clinical models.
Project description:GEMIN5 is a critical component of snRNP assembly complex. Patients carrying novel autosomal recessive variants in the GEMIN5 gene showed symptoms of developmental delay, central hypotonia, and cerebellar ataxia which are distinct than classical spinal muscular atrophy. We performed RNA-seq analysis in iPSC-derived differentiated neurons with biallelic GEMIN5-H913R mutation to identify global alterations in various genes and pathways mediated by GEMIN5 mutations in patients.