Most of the Parkinson's disease (PD) cases are sporadic, although several genes are directly related to PD. Several pathways are central in PD pathogenesis: protein aggregation linked to proteasomal ...impairments, mitochondrial dysfunctions and impairment in dopamine (DA) release. Here we studied the close crossing of mitochondrial dysfunction and aggregation of α-synuclein (α-syn) and in the extension in the dopaminergic neuronal death. Here, using rat primary cultures of mesencephalic neurons, we induced the mitochondrial impairments using "DA-toxins" (MPP+, 6OHDA, rotenone). We showed that the DA-Toxins induced dopaminergic cell death through different pathways: caspase-dependent cell death for 6OHDA; MPP+ stimulated caspase-independent cell death, and rotenone activated both pathways. In addition, a decrease in energy production and/or a development of oxidative stress were observed and were linked to α-syn aggregation with generation of Lewy body-like inclusions (found inside and outside the dopaminergic neurons). We demonstrated that any of induced mitochondrial disturbances and processes of death led to α-syn protein aggregation and finally to cell death. Our study depicts the cell death mechanisms taking place in in vitro models of Parkinson's disease and how mitochondrial dysfunctions is at the cross road of the pathologies of this disease.
Virtual Reality (VR) can play a key role in automotive marketing research, lowering costs and shortening the time to launch a new product. However, few VR applications support automotive customers’ ...experiences during the early stages of product design. This study aims to identify and characterize into attributes the challenges and opportunities for the application of Virtual Reality in car clinics through a systematic review of the literature and patents. We searched PatentScout, ScienceDirect, Springer, and IEEEXplore for studies published between the databases’ inception and July 2020. Of the 77,383 patents and 336,785 articles identified, 72 and 13 were eligible, respectively. We discovered that patents are strongly concentrated by a few inventors, that the United States has the most records, and that the most prevalent applications relate to devices for automatically reading responders’ emotions in virtual environments. The articles revealed sixteen categories of challenges and opportunities: cost, location to customers, flexibility in interactions, model transportation, depth perception, haptic perception, motion, movement perception/physical collision, color and texture, sound feedback, product interaction/manipulation, visual–spatial, graphic quality, intuitiveness, cybersecurity, and cybersickness. Virtual Reality may be used for automotive marketing research but key factors such as hardware and software specification, stimulus quality, and survey objectives must be considered.
Amyotrophic lateral sclerosis (ALS) is the most common fatal motor neuron disease in adults. Numerous studies indicate that ALS is a systemic disease that affects whole body physiology and metabolic ...homeostasis. Using a mouse model of the disease (SOD1G86R), we investigated muscle physiology and motor behavior with respect to muscle metabolic capacity. We found that at 65 days of age, an age described as asymptomatic, SOD1G86R mice presented with improved endurance capacity associated with an early inhibition in the capacity for glycolytic muscle to use glucose as a source of energy and a switch in fuel preference toward lipids. Indeed, in glycolytic muscles we showed progressive induction of pyruvate dehydrogenase kinase 4 expression. Phosphofructokinase 1 was inhibited, and the expression of lipid handling molecules was increased. This mechanism represents a chronic pathologic alteration in muscle metabolism that is exacerbated with disease progression. Further, inhibition of pyruvate dehydrogenase kinase 4 activity with dichloroacetate delayed symptom onset while improving mitochondrial dysfunction and ameliorating muscle denervation. In this study, we provide the first molecular basis for the particular sensitivity of glycolytic muscles to ALS pathology.
Synopsis
Altered metabolic homeostasis is an early event in amyotrophic lateral sclerosis (ALS) manifestation. This study reveals that skeletal muscles stop using glucose as a source of energy but use lipids instead and this chronic pathologic alteration in muscles is exacerbated with disease progression.
The early alteration of muscle metabolic equilibrium between glucose and lipid use impacts on the capacity for muscle to efficiently adapt to increased energetic demands in the SOD1G86R ALS mouse model.
PDK4 is central to these metabolic changes, being upregulated at early asymptomatic stages and increasing throughout disease progression in the SOD1G86R model, as well as in ALS patients.
The metabolic alterations described are specific to glycolytic muscle (TA) in the SOD1G86R model.
Regulation of the glycolytic pathway presents as a potential therapeutic strategy as a drug targeting of PDK4 improves muscle function and overall metabolic status in the SOD1G86R model.
Altered metabolic homeostasis is an early event in amyotrophic lateral sclerosis (ALS) manifestation. This study reveals that skeletal muscles stop using glucose as a source of energy but use lipids instead and this chronic pathologic alteration in muscles is exacerbated with disease progression.
Mitochondria, α-syn fibrils and the endo-lysosomal system are key players in the pathophysiology of Parkinson’s disease. The toxicity of α-syn is amplified by cell-to-cell transmission and ...aggregation of endogenous species in newly invaded neurons. Toxicity of α-syn PFF was investigated using primary cultures of dopaminergic neurons or on aged mice after infusion in the SNpc and combined with mild inhibition of GBA. In primary dopaminergic neurons, application of α-syn PFF induced a progressive cytotoxicity associated with mitochondrial dysfunction, oxidative stress, and accumulation of lysosomes suggesting that exogenous α-syn reached the lysosome (from the endosome). Counteracting the α-syn endocytosis with a clathrin inhibitor, dopaminergic neuron degeneration was prevented. In vivo, α-syn PFF induced progressive neurodegeneration of dopaminergic neurons associated with motor deficits. Histology revealed progressive aggregation of α-syn and microglial activation and accounted for the seeding role of α-syn, injection of which acted as a spark suggesting a triggering of cell-to-cell toxicity. We showed for the first time that a localized SNpc α-syn administration combined with a slight lysosomal deficiency and aging triggered a progressive lesion. The cellular and animal models described could help in the understanding of the human disease and might contribute to the development of new therapies.
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that results in progressive loss of motoneurons, motor weakness and death within 3-5 years after disease onset. ...Therapeutic options remain limited despite substantial number of approaches that have been tested clinically. Many neurotrophic growth factors are known to promote the survival of neurons and foster regeneration in the central nervous system. Various neurotrophic factors have been investigated pre-clinically and clinically for the treatment of ALS. Although pre-clinical data appeared promising, no neurotrophic factors succeeded yet in a clinical phase III trial. In this review we discuss the rationale behind those factors, possible reasons for clinical failures, and argue for a renewal of hope in this powerful class of drugs for the treatment of ALS.
NX210c is a disease-modifying dodecapeptide derived from the subcommissural organ-spondin that is under preclinical and clinical development for the treatment of neurological disorders. Here, using ...whole-cell patch-clamp recordings, we demonstrate that NX210c increased α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)- and GluN2A-containing N-methyl-D-aspartate receptor (GluN2A-NMDAR)-mediated excitatory postsynaptic currents in the brain. Accordingly, using extracellular field excitatory postsynaptic potential recordings, an enhancement of synaptic transmission was shown in the presence of NX210c in two different neuronal circuits. Furthermore, the modulation of synaptic transmission and GluN2A-NMDAR-driven signaling by NX210c restored memory in mice chronically treated with the NMDAR antagonist phencyclidine. Overall, by promoting glutamatergic receptor-related neurotransmission and signaling, NX210c represents an innovative therapeutic opportunity for patients suffering from CNS disorders, injuries, and states with crippling synaptic dysfunctions.
Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset disease characterized by upper and lower motor neuron degeneration, muscle wasting and paralysis. Growing evidence suggests a link between ...changes in lipid metabolism and ALS. Here, we used UPLC/TOF-MS to survey the lipidome in SOD1(G86R) mice, a model of ALS. Significant changes in lipid expression were evident in spinal cord and skeletal muscle before overt neuropathology. In silico analysis also revealed appreciable changes in sphingolipids including ceramides and glucosylceramides (GlcCer). HPLC analysis showed increased amounts of GlcCer and downstream glycosphingolipids (GSLs) in SOD1(G86R) muscle compared with wild-type littermates. Glucosylceramide synthase (GCS), the enzyme responsible for GlcCer biosynthesis, was up-regulated in muscle of SOD1(G86R) mice and ALS patients, and in muscle of wild-type mice after surgically induced denervation. Conversely, inhibition of GCS in wild-type mice, following transient peripheral nerve injury, reversed the overexpression of genes in muscle involved in oxidative metabolism and delayed motor recovery. GCS inhibition in SOD1(G86R) mice also affected the expression of metabolic genes and induced a loss of muscle strength and morphological deterioration of the motor endplates. These findings suggest that GSLs may play a critical role in ALS muscle pathology and could lead to the identification of new therapeutic targets.
Amyotrophic lateral sclerosis (ALS) is a multifactorial and fatal neurodegenerative disease. Growing evidence connects sphingolipid metabolism to the pathophysiology of ALS. In particular, levels of ...ceramides, glucosylceramides, and gangliosides are dysregulated in the central nervous system and at the neuromuscular junctions of both animal models and patients. Glucosylceramide is the main precursor of complex glycosphingolipids that is degraded by lysosomal (GBA1) or non-lysosomal (GBA2) glucocerebrosidase. Here, we report that GBA2, but not GBA1, activity is markedly increased in the spinal cord, of SOD1
mice, an animal model of familial ALS, even before disease onset. We therefore investigated the effects of ambroxol hydrochloride, a known GBA2 inhibitor, in SOD1
mice. A presymptomatic administration of ambroxol hydrochloride, in the drinking water, delayed disease onset, protecting neuromuscular junctions, and the number of functional spinal motor neurons. When administered at disease onset, ambroxol hydrochloride delayed motor function decline, protected neuromuscular junctions, and extended overall survival of the SOD1
mice. In addition, ambroxol hydrochloride improved motor recovery and muscle re-innervation after transient sciatic nerve injury in non-transgenic mice and promoted axonal elongation in an
model of motor unit. Our study suggests that ambroxol hydrochloride promotes and protects motor units and improves axonal plasticity, and that this generic compound is a promising drug candidate for ALS.
Amyotrophic Lateral Sclerosis (ALS) is a fatal motoneuron disease, characterized by progressive weakness, muscle wasting and death ensuing 3-5 years after diagnosis. The etiology of ALS is complex ...and therapeutic approaches rely mostly on transgenic animal models with SOD-1 mutations. Most frequently employed is a mouse line transgenic for SOD-1 (SOD-1 Tg) that contains a point mutation at amino acid position 93 (G->A), present in patients suffering from a familial form of amyotrophic lateral sclerosis. Here we report on a SOD-1 (G93A) Tg mouse line with abnormally delayed onset of disease and prolonged survival. This phenotype arose spontaneously in our colony of the classic SOD-1 (G93A) line. We found that the copy number of the SOD-1 transgene was drastically decreased. We established a new breeding colony, the SOD-1 (G93A)(PS) line (PS for prolonged survival) where the phenotype is stably inherited for 4 generations now. The mice develop symptoms at an age of approximately 12 months and die at 15 months of age. The delayed development of disease may more closely mimic human pathophysiology, and studying drug effects in this model may yield added confidence for potential efficacy of ALS drug candidates.
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