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Revista de Neurologia Jul 2024The XVI Post-ECTRIMS meeting took place in Seville on 20 and 21 October 2023. This meeting was attended by neurologists specialising in multiple sclerosis (MS) from... (Review)
Review
The XVI Post-ECTRIMS meeting took place in Seville on 20 and 21 October 2023. This meeting was attended by neurologists specialising in multiple sclerosis (MS) from Spain, who shared a summary of the most interesting innovations at the ECTRIMS congress, which had taken place in Milan the previous week. The aim of this article is to summarise new developments related to the pathogenesis, diagnosis and prognosis of MS. The contributions of innate immunity and central nervous system resident cells, including macrophages and microglia in MS pathophysiology and as therapeutic targets were discussed. Compartmentalised intrathecal inflammation was recognised as central to understanding the progression of MS, and the relationship between inflammatory infiltrates and disease progression was highlighted. Perspectives in demyelinating pathologies were reviewed, focusing on neuromyelitis optica and myelin oligodendrocyte glycoprotein antibody-associated disease, highlighting their pathophysiological and diagnostic differences compared to MS. Advances in neuroimaging were also discussed, and especially the analysis of active chronic lesions, such as paramagnetic rim lesions. In the absence of clinical improvements in trials of remyelinating treatments, methodological strategies to optimise the design of future studies were proposed. Breakthroughs in detecting the prodromal phase of MS, the use of biomarkers in body fluids to assess activity, progression and treatment response, and research on progression independent of flares were addressed. The need to define criteria for radiologically isolated syndrome and to clarify the concept was also discussed.
Topics: Humans; Multiple Sclerosis; Congresses as Topic
PubMed: 38934946
DOI: 10.33588/rn.7901.2024170 -
Neural Regeneration Research Jun 2024Inflammation plays a crucial role in the regeneration of fish and avian retinas. However, how inflammation regulates Müller glia (MG) reprogramming remains unclear....
Inflammation plays a crucial role in the regeneration of fish and avian retinas. However, how inflammation regulates Müller glia (MG) reprogramming remains unclear. Here, we used single-cell RNA sequencing to investigate the cell heterogeneity and interactions of MG and immune cells in the regenerating zebrafish retina. We first showed that two types of quiescent MG (resting MG1 and MG2) reside in the uninjured retina. Following retinal injury, resting MG1 transitioned into an activated state expressing known reprogramming genes, while resting MG2 gave rise to rod progenitors. We further showed that retinal microglia can be categorized into three subtypes (microglia-1, microglia-2, and proliferative) and pseudotime analysis demonstrated dynamic changes in microglial status following retinal injury. Analysis of cell-cell interactions indicated extensive crosstalk between immune cells and MG, with many interactions shared among different immune cell types. Finally, we showed that inflammation activated Jak1-Stat3 signaling in MG, promoting their transition from a resting to an activated state. Our study reveals the cell heterogeneity and crosstalk of immune cells and MG in zebrafish retinal repair, and may provide valuable insights into future mammalian retina regeneration.
PubMed: 38934409
DOI: 10.4103/NRR.NRR-D-23-02083 -
Neural Regeneration Research Jun 2024Microglial activation that occurs rapidly after closed head injury may play important and complex roles in neuroinflammation-associated neuronal damage and repair. We...
Microglial activation that occurs rapidly after closed head injury may play important and complex roles in neuroinflammation-associated neuronal damage and repair. We previously reported that induced neural stem cells can modulate the behavior of activated microglia via CXCL12/CXCR4 signaling, influencing their activation such that they can promote neurological recovery. However, the mechanism of CXCR4 upregulation in induced neural stem cells remains unclear. In this study, we found that nuclear factor-κB activation induced by closed head injury mouse serum in microglia promoted CXCL12 and tumor necrosis factor-α expression but suppressed insulin-like growth factor-1 expression. However, recombinant complement receptor 2-conjugated Crry (CR2-Crry) reduced the effects of closed head injury mouse serum-induced nuclear factor-κB activation in microglia and the levels of activated microglia, CXCL12, and tumor necrosis factor-α. Additionally, we observed that, in response to stimulation (including stimulation by CXCL12 secreted by activated microglia), CXCR4 and Crry levels can be upregulated in induced neural stem cells via the interplay among CXCL12/CXCR4, Crry, and Akt signaling to modulate microglial activation. In agreement with these in vitro experimental results, we found that Akt activation enhanced the immunoregulatory effects of induced neural stem cell grafts on microglial activation, leading to the promotion of neurological recovery via insulin-like growth factor-1 secretion and the neuroprotective effects of induced neural stem cell grafts through CXCR4 and Crry upregulation in the injured cortices of closed head injury mice. Notably, these beneficial effects of Akt activation in induced neural stem cells were positively correlated with the therapeutic effects of induced neural stem cells on neuronal injury, cerebral edema, and neurological disorders post-closed head injury. In conclusion, our findings reveal that Akt activation may enhance the immunoregulatory effects of induced neural stem cells on microglial activation via upregulation of CXCR4 and Crry, thereby promoting induced neural stem cell-mediated improvement of neuronal injury, cerebral edema, and neurological disorders following closed head injury.
PubMed: 38934402
DOI: 10.4103/NRR.NRR-D-23-01495 -
Neural Regeneration Research Jun 2024Glial cells play crucial roles in regulating physiological and pathological functions, including sensation, the response to infection and acute injury, and chronic...
Glial cells play crucial roles in regulating physiological and pathological functions, including sensation, the response to infection and acute injury, and chronic neurodegenerative disorders. Glial cells include astrocytes, microglia, and oligodendrocytes in the central nervous system, and satellite glial cells and Schwann cells in the peripheral nervous system. Despite the greater understanding of glial cell types and functional heterogeneity achieved through single-cell and single-nucleus RNA sequencing in animal models, few studies have investigated the transcriptomic profiles of glial cells in the human spinal cord. Here, we used high-throughput single-nucleus RNA sequencing and spatial transcriptomics to map the cellular and molecular heterogeneity of astrocytes, microglia, and oligodendrocytes in the human spinal cord. To explore the conservation and divergence across species, we compared these findings with those from mice. In the human spinal cord, astrocytes, microglia, and oligodendrocytes were each divided into six distinct transcriptomic subclusters. In the mouse spinal cord, astrocytes, microglia, and oligodendrocytes were divided into five, four, and five distinct transcriptomic subclusters, respectively.The comparative results revealed substantial heterogeneity in all glial cell types between humans and mice. Additionally, we detected sex differences in gene expression in human spinal cord glial cells. Specifically, in all astrocyte subtypes, the levels of NEAT1 and CHI3L1 were higher in males than in females, whereas the levels of CST3 were lower in males than in females. In all microglial subtypes, all differentially expressed genes were located on the sex chromosomes. In addition to sex-specific gene differences, the levels of MT-ND4, MT2A, MT-ATP6, MT-CO3, MT-ND2, MT-ND3, and MT-CO2 in all spinal cord oligodendrocyte subtypes were higher in females than in males. Collectively, the present dataset extensively characterizes glial cell heterogeneity and offers a valuable resource for exploring the cellular basis of spinal cord-related illnesses, including chronic pain, amyotrophic lateral sclerosis, and multiple sclerosis.
PubMed: 38934400
DOI: 10.4103/NRR.NRR-D-23-01876 -
Neural Regeneration Research Jun 2024Spinal cord injury is an intractable traumatic injury. The most common hurdles faced during spinal cord injury are failure of axonal regrowth and reconnection to target...
Spinal cord injury is an intractable traumatic injury. The most common hurdles faced during spinal cord injury are failure of axonal regrowth and reconnection to target sites. These also tend to be the most challenging issues in spinal cord injury. As spinal cord injury progresses to the chronic phase, lost motor and sensory functions are not recovered. Several reasons may be attributed to the failure of recovery from chronic spinal cord injury. These include factors that inhibit axonal growth such as activated astrocytes, chondroitin sulfate proteoglycan, myelin-associated proteins, inflammatory microglia, and fibroblasts that accumulate at lesion sites. Skeletal muscle atrophy due to denervation is another chronic and detrimental spinal cord injury-specific condition. Although several intervention strategies based on multiple outlooks have been attempted for treating spinal cord injury, few approaches have been successful. To treat chronic spinal cord injury, neural cells or tissue substitutes may need to be supplied in the cavity area to enable possible axonal growth. Additionally, stimulating axonal growth activity by extrinsic factors is extremely important and essential for maintaining the remaining host neurons and transplanted neurons. This review focuses on pharmacotherapeutic approaches using small compounds and proteins to enable axonal growth in chronic spinal cord injury. This review presents some of these candidates that have shown promising outcomes in basic research (in vivo animal studies) and clinical trials: AA-NgR(310)ecto-Fc (AXER-204), fasudil, phosphatase and tensin homolog protein (PTEN) antagonist peptide 4, chondroitinase ABC, intracellular sigma peptide, (-)-epigallocatechin gallate, matrine, acteoside, pyrvate kinase M2, diosgenin, granulocyte-colony stimulating factor, and fampridine-sustained release. Although the current situation suggests that drug-based therapies to recover function in chronic spinal cord injury are limited, potential candidates have been identified through basic research, and these candidates may be subjects of clinical studies in the future. Moreover, cocktail therapy comprising drugs with varied underlying mechanisms may be effective in treating the refractory status of chronic spinal cord injury.
PubMed: 38934397
DOI: 10.4103/NRR.NRR-D-24-00176 -
Autophagy Jun 2024A multitude of cellular responses to intrinsic and extrinsic signals converge on macroautophagy/autophagy, a conserved catabolic process that degrades cytoplasmic...
A multitude of cellular responses to intrinsic and extrinsic signals converge on macroautophagy/autophagy, a conserved catabolic process that degrades cytoplasmic constituents and organelles in the lysosome, particularly during starvation or stress. In addition to protein degradation, autophagy is deeply interconnected with unconventional protein secretion and polarized sorting at multiple levels within eukaryotic cells. Secretory autophagy (SA) has been recognized as a novel mechanism in which autophagosomes fuse with the plasma membrane and actively participate in the secretion of a series of cytosolic proteins, ranging from tissue remodeling factors to inflammatory molecules of the IL1 family. SA is partially controlled by the glucocorticoid-responsive, HSP90 co-chaperone FKBP5 and members of the SNARE proteins, SEC22B, SNAP23, SNAP29, STX3 and STX4. SA deregulation is implicated in several inflammatory pathologies, including cancer, cell death and degeneration. However, the key molecular mechanisms governing SA and its regulation remain elusive, as does its role in neuroinflammation and neurodegeneration. To further characterize SA and pinpoint its involvement in neuroinflammatory processes, we studied SA-relevant protein interaction networks in mouse brain, microglia and human postmortem brain tissue from control subjects and Alzheimer disease cases. We demonstrate that SA regulates neuroinflammation-mediated neurodegeneration via SKA2 and FKBP5 signaling.
PubMed: 38934263
DOI: 10.1080/15548627.2024.2373675 -
Frontiers in Aging Neuroscience 2024Dementia is a progressive neurodegenerative condition, while metabolic syndrome (MetS) is characterized by a combination of metabolic abnormalities such as hypertension,...
BACKGROUND
Dementia is a progressive neurodegenerative condition, while metabolic syndrome (MetS) is characterized by a combination of metabolic abnormalities such as hypertension, high blood sugar, and obesity. There exists a connection and overlap between the two conditions in certain aspects, and both are influenced to varying degrees by the process of aging. This study presents an overview of the current research landscape regarding dementia and MetS through bibliometric analysis.
METHODS
A systematic search was conducted to retrieve relevant literature on dementia and MetS published between 1 January 2000, and 30 November 2023, from the Web of Science Core Collection database. Various bibliometric tools, including VOSviewer, CiteSpace, and the R software package "bibliometrix," were utilized for analysis.
RESULTS
A total of 717 articles were identified, showing an upward trend in annual publications. Leading contributors included the United States, Italy, and China, with institutions such as the University of California System at the forefront. The emerged as the top publisher, while research published in garnered significant citations. Noteworthy authors encompassed Panza, Francesco; Frisardi, Vincenza; and Feldman, Eva L, with Kristine Yaffe being the most cited author (280 citations). Recent studies have focused on themes like "gut microbiota," "neuroinflammation," "fatty acids," and "microglia."
CONCLUSION
This bibliometric analysis summarizes the foundational knowledge structure in the realm of dementia and MetS from 2000 to 2023. By highlighting current research frontiers and trending topics, this analysis serves as a valuable reference for researchers in the field.
PubMed: 38934020
DOI: 10.3389/fnagi.2024.1400589 -
Frontiers in Neuroscience 2024Parkinson's disease (PD) is a common neurodegenerative disease with a rapid increase in incidence in recent years. Existing treatments cannot slow or stop the...
BACKGROUND
Parkinson's disease (PD) is a common neurodegenerative disease with a rapid increase in incidence in recent years. Existing treatments cannot slow or stop the progression of PD. It was proposed that neuroinflammation leads to neuronal death, making targeting neuroinflammation a promising therapeutic strategy. Our previous studies have demonstrated that rhein protects neurons by inhibiting neuroinflammation, and it has been found to exhibit neuroprotective effects in Alzheimer's disease and epilepsy, but its neuroprotective mechanisms and effects on PD are still unclear.
METHODS
PD animal model was induced by 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP). ELISA, RT-qPCR, western blot and Immunofluorescence were used to detect the levels of inflammatory cytokines and M1 polarization markers. The protein expression levels of signaling pathways were measured by western blot. Hematoxylin-eosin (HE) staining showed that rhein did not damage the liver and kidney. Two behavioral tests, pole test and rotarod test, were used to evaluate the improvement effect of rhein on movement disorders. The number of neurons in the substantia nigra was evaluated by Nissl staining. Immunohistochemistry and western blot were used to detect tyrosine hydroxylase (TH) and α-synuclein.
RESULTS
Rhein inhibited the activation of MAPK/IκB signaling pathway and reduced the levels of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and M1 polarization markers of microglia . In a mouse model of PD, rhein ameliorated movement disorders, reduced dopaminergic neuron damage and α-synuclein deposition.
CONCLUSION
Rhein inhibits neuroinflammation through MAPK/IκB signaling pathway, thereby reducing neurodegeneration, α-synuclein deposition, and improving movement disorders in Parkinson's disease.
PubMed: 38933815
DOI: 10.3389/fnins.2024.1396345 -
Frontiers in Cellular Neuroscience 2024Human cerebral organoids (hCOs) derived from pluripotent stem cells are very promising for the study of neurodevelopment and the investigation of the healthy or diseased...
INTRODUCTION
Human cerebral organoids (hCOs) derived from pluripotent stem cells are very promising for the study of neurodevelopment and the investigation of the healthy or diseased brain. To help establish hCOs as a powerful research model, it is essential to perform the morphological characterization of their cellular components in depth.
METHODS
In this study, we analyzed the cell types consisting of hCOs after culturing for 45 days using immunofluorescence and reverse transcriptase qualitative polymerase chain reaction (RT-qPCR) assays. We also analyzed their subcellular morphological characteristics by transmission electron microscopy (TEM).
RESULTS
Our results show the development of proliferative zones to be remarkably similar to those found in human brain development with cells having a polarized structure surrounding a central cavity with tight junctions and cilia. In addition, we describe the presence of immature and mature migrating neurons, astrocytes, oligodendrocyte precursor cells, and microglia-like cells.
DISCUSSION
The ultrastructural characterization presented in this study provides valuable information on the structural development and morphology of the hCO, and this information is of general interest for future research on the mechanisms that alter the cell structure or function of hCOs.
PubMed: 38933177
DOI: 10.3389/fncel.2024.1406839 -
Nuclear Medicine and Molecular Imaging Jun 2024Neuroinflammation is associated with the pathophysiologies of neurodegenerative and psychiatric disorders. Evaluating neuroinflammation using positron emission... (Review)
Review
Neuroinflammation is associated with the pathophysiologies of neurodegenerative and psychiatric disorders. Evaluating neuroinflammation using positron emission tomography (PET) plays an important role in the early diagnosis and determination of proper treatment of brain diseases. To quantify neuroinflammatory responses in vivo, many PET tracers have been developed using translocator proteins, imidazole-2 binding site, cyclooxygenase, monoamine oxidase-B, adenosine, cannabinoid, purinergic P2X7, and CSF-1 receptors as biomarkers. In this review, we introduce the latest developments in PET tracers that can image neuroinflammation, focusing on clinical trials, and further consider their current implications.
PubMed: 38932754
DOI: 10.1007/s13139-023-00831-4