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Genes Jun 2024Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease targeting the brain and spinal cord. Non-neuronal cells, including macrophages, may contribute to the...
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease targeting the brain and spinal cord. Non-neuronal cells, including macrophages, may contribute to the disruption of motor neurons (MNs), neuromuscular junction dismantling and clinical signs of ALS. Understanding the modality and the effect of MNs-macrophage communication is pivotal. Here, we focus on extracellular vesicle (EVS)-mediated communication and, in particular, we analyze the response of macrophages. NSC-34 cells transfected with mutant SOD1 (G93A, A4V, G85R, G37R) and differentiated towards MN-like cells, and Raw 264.7 macrophages are the cellular models of the study. mSOD1 NSC-34 cells release a high number of vesicles, both large-lEVs (300 nm diameter) and small-sEVs (90 nm diameter), containing inflammation-modulating molecules, and are efficiently taken up by macrophages. RT-PCR analysis of inflammation mediators demonstrated that the conditioned medium of mSOD1 NSC-34 cells polarizes Raw 264.7 macrophages towards both pro-inflammatory and anti-inflammatory phenotypes. sEVs act on macrophages in a time-dependent manner: an anti-inflammatory response mediated by TGFβ firstly starts (12 h); successively, the response shifts towards a pro-inflammation IL-1β-mediated (48 h). The response of macrophages is strictly dependent on the SOD1 mutation type. The results suggest that EVs impact physiological and behavioral macrophage processes and are of potential relevance to MN degeneration.
Topics: Animals; Extracellular Vesicles; Mice; RAW 264.7 Cells; Superoxide Dismutase-1; Macrophages; Amyotrophic Lateral Sclerosis; Motor Neurons; Inflammation; Mutation; Transfection; Humans
PubMed: 38927671
DOI: 10.3390/genes15060735 -
Genes May 2024Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by progressive damage to both upper and lower motor neurons. Genetic...
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by progressive damage to both upper and lower motor neurons. Genetic factors are known to play a crucial role in ALS, as genetic studies not only advance our comprehension of disease mechanisms but also help unravel the complex phenotypes exhibited by patients. To gain further insights into the genetic landscape of ALS in the Chinese population and explore genotype-phenotype correlations among individuals, we conducted whole-genome sequencing to screen genes in 34 Chinese familial ALS (FALS) probands lacking the most common ALS-associated genes. Within this cohort, we identified a rare heterozygous missense mutation in the N-terminal domain of (c.86A>G) in one of the probands. This finding is significant as mutations in the gene have been implicated in ALS in European cohorts since 2018, predominantly characterized by C-terminal mutations. Analysis of the clinical phenotype within this familial lineage revealed a delayed onset of symptoms, an extended survival duration, and initial manifestations in both upper limbs. These observations underscore the clinical heterogeneity observed in ALS patients harboring mutations. In conclusion, our study contributes to the growing body of evidence linking to ALS and enhances our understanding of the intricate genetic landscape of this disease.
Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Amyotrophic Lateral Sclerosis; China; East Asian People; Kinesins; Mutation; Mutation, Missense; Pedigree; Phenotype; Whole Genome Sequencing
PubMed: 38927616
DOI: 10.3390/genes15060680 -
Biomedicines Jun 2024Cannabinoids are reported to have neuroprotective properties and play a role in neurogenesis and neuroplasticity in in vitro and in vivo models. Cannabinol (CBN) is a...
Cannabinoids are reported to have neuroprotective properties and play a role in neurogenesis and neuroplasticity in in vitro and in vivo models. Cannabinol (CBN) is a minor cannabinoid produced by the degradation of Δ-tetrahydrocannabinol in L. and exhibits anti-oxidant, analgesic, anti-bacterial, and anti-inflammatory effects. In this study, we explored the biological effects of 20 µM CBN (6.20 µg/mL) on differentiated NSC-34 cells by MTT assay and next-generation sequencing analysis on the transcriptome. KEGG and Gene Ontology enrichment analyses have been performed to evaluate potential CBN-associated processes. Our results highlighted the absence of any cytotoxic effect of CBN. The comparative transcriptomic analysis pointed out the downregulation of , and genes, which are known to suppress the cell cycle. , , , , , , , , , , , , , , , and genes, renowned for their role as cell cycle progression activators, were instead upregulated. Our work suggests that CBN regulates the expression of many genes related to the cell cycle, which are required for axonal maturation, migration, and synaptic plasticity, while not affecting the expression of genes involved in cell death or tumorigenesis.
PubMed: 38927547
DOI: 10.3390/biomedicines12061340 -
Biomedicines May 2024Spinal muscular atrophy (SMA) is an orphan disease characterized by the progressive degeneration of spinal alpha motor neurons. In recent years, nusinersen and several...
Spinal muscular atrophy (SMA) is an orphan disease characterized by the progressive degeneration of spinal alpha motor neurons. In recent years, nusinersen and several other drugs have been approved for the treatment of this disease. Transcutaneous spinal cord stimulation (tSCS) modulates spinal neuronal networks, resulting in changes in locomotion and posture in patients with severe spinal cord injury and stroke. We hypothesize that tSCS can activate motor neurons that are intact and restored by medication, slow the decline in motor activity, and contribute to the development of motor skills in SMA patients. Thirty-seven children and adults with SMA types 2 and 3 participated in this study. The median duration of drug treatment was over 20 months. The application of tSCS was performed during physical therapy for 20-40 min per day for ~12 days. Outcome measures were specific SMA motor scales, goniometry of contractured joints, and forced vital capacity. Significant increases in motor function, improved respiratory function, and decreased contracture were observed in both type 2 and 3 SMA participants. The magnitude of functional changes was not associated with participant age. Further studies are needed to elucidate the reasons for the beneficial effects of spinal cord electrical stimulation on SMA.
PubMed: 38927369
DOI: 10.3390/biomedicines12061162 -
Biomolecules Jun 2024One of the biggest problems in the treatment of idiopathic Parkinson's disease is the lack of new drugs that slow its progression. L-Dopa remains the star drug in the... (Review)
Review
One of the biggest problems in the treatment of idiopathic Parkinson's disease is the lack of new drugs that slow its progression. L-Dopa remains the star drug in the treatment of this disease, although it induces severe side effects. The failure of clinical studies with new drugs depends on the use of preclinical models based on neurotoxins that do not represent what happens in the disease since they induce rapid and expansive neurodegeneration. We have recently proposed a single-neuron degeneration model for idiopathic Parkinson's disease that requires years to accumulate enough lost neurons for the onset of motor symptoms. This single-neuron degeneration model is based on the excessive formation of aminochrome during neuromelanin synthesis that surpass the neuroprotective action of the enzymes DT-diaphorase and glutathione transferase M2-2, which prevent the neurotoxic effects of aminochrome. Although the neurotoxic effects of aminochrome do not have an expansive effect, a stereotaxic injection of this endogenous neurotoxin cannot be used to generate a preclinical model in an animal. Therefore, the aim of this review is to evaluate the strategies for pharmacologically increasing the expression of DT diaphorase and GSTM2-2 and molecules that induce the expression of vesicular monoamine transporter 2, such as pramipexole.
Topics: Humans; Parkinson Disease; Animals; Neurons; Nerve Degeneration; Glutathione Transferase; Neuroprotective Agents; Disease Models, Animal; Antiparkinson Agents
PubMed: 38927076
DOI: 10.3390/biom14060673 -
Nature Jun 2024Animal movement is controlled by motor neurons (MNs), which project out of the central nervous system to activate muscles. MN activity is coordinated by complex premotor...
Animal movement is controlled by motor neurons (MNs), which project out of the central nervous system to activate muscles. MN activity is coordinated by complex premotor networks that facilitate the contribution of individual muscles to many different behaviours. Here we use connectomics to analyse the wiring logic of premotor circuits controlling the Drosophila leg and wing. We find that both premotor networks cluster into modules that link MNs innervating muscles with related functions. Within most leg motor modules, the synaptic weights of each premotor neuron are proportional to the size of their target MNs, establishing a circuit basis for hierarchical MN recruitment. By contrast, wing premotor networks lack proportional synaptic connectivity, which may enable more flexible recruitment of wing steering muscles. Through comparison of the architecture of distinct motor control systems within the same animal, we identify common principles of premotor network organization and specializations that reflect the unique biomechanical constraints and evolutionary origins of leg and wing motor control.
PubMed: 38926579
DOI: 10.1038/s41586-024-07600-z -
Nature Jun 2024A deep understanding of how the brain controls behaviour requires mapping neural circuits down to the muscles that they control. Here, we apply automated tools to...
A deep understanding of how the brain controls behaviour requires mapping neural circuits down to the muscles that they control. Here, we apply automated tools to segment neurons and identify synapses in an electron microscopy dataset of an adult female Drosophila melanogaster ventral nerve cord (VNC), which functions like the vertebrate spinal cord to sense and control the body. We find that the fly VNC contains roughly 45 million synapses and 14,600 neuronal cell bodies. To interpret the output of the connectome, we mapped the muscle targets of leg and wing motor neurons using genetic driver lines and X-ray holographic nanotomography. With this motor neuron atlas, we identified neural circuits that coordinate leg and wing movements during take-off. We provide the reconstruction of VNC circuits, the motor neuron atlas and tools for programmatic and interactive access as resources to support experimental and theoretical studies of how the nervous system controls behaviour.
PubMed: 38926570
DOI: 10.1038/s41586-024-07389-x -
ENeuro Jun 2024Layer 6 corticothalamic (L6 CT) neurons provide massive input to the thalamus, and these feedback connections enable the cortex to influence its own sensory input by...
Layer 6 corticothalamic (L6 CT) neurons provide massive input to the thalamus, and these feedback connections enable the cortex to influence its own sensory input by modulating thalamic excitability. However, the functional role(s) feedback serves during sensory processing is unclear. One hypothesis is that CT feedback is under the control of extra-sensory signals originating from higher-order cortical areas, yet we know nothing about the mechanisms of such control. It is also unclear whether such regulation is specific to CT neurons with distinct thalamic connectivity. Using mice (either sex) combined with in vitro electrophysiology techniques, optogenetics, and retrograde labeling, we describe studies of vibrissal primary motor cortex (vM1) influences on different CT neurons in the vibrissal primary somatosensory cortex (vS1) with distinct intrathalamic axonal projections. We found that vM1 inputs are highly selective, evoking stronger postsynaptic responses in Dual ventral posterior medial nucleus (VPm) and posterior medial nucleus (POm) projecting CT neurons located in lower L6a than VPm-only projecting CT cells in upper L6a. A targeted analysis of the specific cells and synapses involved revealed that the greater responsiveness of Dual CT neurons was due to their distinctive intrinsic membrane properties and synaptic mechanisms. These data demonstrate that vS1 has at least two discrete L6 CT subcircuits distinguished by their thalamic projection patterns, intrinsic physiology, and functional connectivity with vM1. Our results also provide insights into how a distinct CT subcircuit may serve specialized roles specific to contextual modulation of tactile-related sensory signals in the somatosensory thalamus during active vibrissa movements. Layer 6 corticothalamic (L6 CT) feedback circuits are ubiquitous across mammalian species and modalities, and their activities have a strong influence on thalamic excitability and information throughput to the neocortex. Despite clear evidence of CT effects on the thalamus, we know relatively little about how CT cells themselves are regulated. Our results show that input from the primary motor cortex strongly excites a subclass of CT neurons in the primary somatosensory cortex that innervate both core and higher-order somatosensory nuclei rather than those exclusively targeting core somatosensory thalamus. The cortico-cortico-thalamic pathway formed by these connections establishes a circuit-level substrate for supporting CT influence operating under the guidance of ongoing motor activities.
PubMed: 38926084
DOI: 10.1523/ENEURO.0255-24.2024 -
Journal of Neurology, Neurosurgery, and... Jun 2024
PubMed: 38925911
DOI: 10.1136/jnnp-2024-333939 -
Chemico-biological Interactions Jun 2024Nicotinamide riboside (NR) is a precursor and exogenous supplement of nicotinamide adenine dinucleotide (NAD). NR has been shown to play a beneficial role in a variety...
Nicotinamide Riboside Ameliorates Survival Time and Motor Dysfunction in an MPTP-Induced Parkinson's Disease Zebrafish Model through Effects on Glucose Metabolism and Endoplasmic Reticulum Stress.
Nicotinamide riboside (NR) is a precursor and exogenous supplement of nicotinamide adenine dinucleotide (NAD). NR has been shown to play a beneficial role in a variety of neurodegenerative diseases. A phase 1 clinical trial identified NR as a potential neuroprotective therapy for Parkinson's disease (PD). However, the mechanism of action of NR in PD has not been fully elucidated. Therefore, the present study aimed to investigate the potential effects of NR on a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model in zebrafish and its underlying mechanisms. The results showed that NR improved motor dysfunction, survival time, dopamine neurons, and peripheral neurons, as well as the NAD levels in the MPTP-affected PD zebrafish model. In addition, transcriptome sequencing analysis revealed that, after NR treatment, differentially expressed genes were significantly enriched in the glucose metabolism and protein processing pathways in the endoplasmic reticulum (ER). Quantitative PCR (qPCR) revealed that the mRNA levels of the glycoheterotrophic enzyme (involved in glucose metabolism) were significantly decreased, and the glycolytic enzyme mRNA expression levels were significantly increased. The results of the non-targeted metabolomic analysis showed that NR treatment significantly increased the levels of metabolites such as nicotinic acid and nicotinamide, in addition to α-D-glucose from the gluconeogenesis and glycolysis metabolism pathways and some of the glucogenic amino acids, such as glutamine. Importantly, NR ameliorated MPTP-induced endoplasmic reticulum stress (ERS) in the PD zebrafish model through the Perk-Eif2α-Atf4-Chop pathway. These results highlight the neuroprotective effect of NR in the present PD zebrafish model through modulation of glucose metabolism and ER stress via the Perk-Eif2α-Atf4-Chop pathway and provide valuable mechanistic insights into the treatment of PD.
PubMed: 38925209
DOI: 10.1016/j.cbi.2024.111118