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Huang Z. Evidence that Alzheimer's Disease Is a Disease of Competitive Synaptic Plasticity Gone Awry. J Alzheimers Dis 2024:JAD240042. [PMID: 38669548 DOI: 10.3233/jad-240042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Mounting evidence indicates that a physiological function of amyloid-β (Aβ) is to mediate neural activity-dependent homeostatic and competitive synaptic plasticity in the brain. I have previously summarized the lines of evidence supporting this hypothesis and highlighted the similarities between Aβ and anti-microbial peptides in mediating cell/synapse competition. In cell competition, anti-microbial peptides deploy a multitude of mechanisms to ensure both self-protection and competitor elimination. Here I review recent studies showing that similar mechanisms are at play in Aβ-mediated synapse competition and perturbations in these mechanisms underpin Alzheimer's disease (AD). Specifically, I discuss evidence that Aβ and ApoE, two crucial players in AD, co-operate in the regulation of synapse competition. Glial ApoE promotes self-protection by increasing the production of trophic monomeric Aβ and inhibiting its assembly into toxic oligomers. Conversely, Aβ oligomers, once assembled, promote the elimination of competitor synapses via direct toxic activity and amplification of "eat-me" signals promoting the elimination of weak synapses. I further summarize evidence that neuronal ApoE may be part of a gene regulatory network that normally promotes competitive plasticity, explaining the selective vulnerability of ApoE expressing neurons in AD brains. Lastly, I discuss evidence that sleep may be key to Aβ-orchestrated plasticity, in which sleep is not only induced by Aβ but is also required for Aβ-mediated plasticity, underlining the link between sleep and AD. Together, these results strongly argue that AD is a disease of competitive synaptic plasticity gone awry, a novel perspective that may promote AD research.
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Affiliation(s)
- Zhen Huang
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI, USA
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2
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Lopes DM, Wells JA, Ma D, Wallis L, Park D, Llewellyn SK, Ahmed Z, Lythgoe MF, Harrison IF. Glymphatic inhibition exacerbates tau propagation in an Alzheimer's disease model. Alzheimers Res Ther 2024; 16:71. [PMID: 38576025 PMCID: PMC10996277 DOI: 10.1186/s13195-024-01439-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/26/2024] [Indexed: 04/06/2024]
Abstract
BACKGROUND The aggregation and spread of misfolded amyloid structured proteins, such as tau and α-synuclein, are key pathological features associated with neurodegenerative disorders, including Alzheimer's and Parkinson's disease. These proteins possess a prion-like property, enabling their transmission from cell to cell leading to propagation throughout the central and peripheral nervous systems. While the mechanisms underlying their intracellular spread are still being elucidated, targeting the extracellular space has emerged as a potential therapeutic approach. The glymphatic system, a brain-wide pathway responsible for clearing extracellular metabolic waste from the central nervous system, has gained attention as a promising target for removing these toxic proteins. METHODS In this study, we investigated the impact of long-term modulation of glymphatic function on tau aggregation and spread by chronically treating a mouse model of tau propagation with a pharmacological inhibitor of AQP4, TGN-020. Thy1-hTau.P301S mice were intracerebrally inoculated with tau into the hippocampus and overlying cortex, and subsequently treated with TGN-020 (3 doses/week, 50 mg/kg TGN-020, i.p.) for 10-weeks. During this time, animal memory was studied using cognitive behavioural tasks, and structural MR images were acquired of the brain in vivo prior to brain extraction for immunohistochemical characterisation. RESULTS Our findings demonstrate increased tau aggregation in the brain and transhemispheric propagation in the hippocampus following the inhibition of glymphatic clearance. Moreover, disruption of the glymphatic system aggravated recognition memory in tau inoculated mice and exacerbated regional changes in brain volume detected in the model. When initiation of drug treatment was delayed for several weeks post-inoculation, the alterations were attenuated. CONCLUSIONS These results indicate that by modulating AQP4 function and, consequently, glymphatic clearance, it is possible to modify the propagation and pathological impact of tau in the brain, particularly during the initial stages of the disease. These findings highlight the critical role of the glymphatic system in preserving healthy brain homeostasis and offer valuable insights into the therapeutic implications of targeting this system for managing neurodegenerative diseases characterized by protein aggregation and spread.
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Affiliation(s)
- Douglas M Lopes
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
| | - Jack A Wells
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
| | - Da Ma
- Department of Internal Medicine, Section of Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Lauren Wallis
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
| | - Daniel Park
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
| | - Sophie K Llewellyn
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
| | - Zeshan Ahmed
- Neuroscience Next Generation Therapeutics (NGTx), Eli Lilly and Company, Cambridge, MA, USA
| | - Mark F Lythgoe
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
| | - Ian F Harrison
- Centre for Advanced Biomedical Imaging, Department of Imaging, Division of Medicine, University College London, Paul O'Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK.
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Zimmer TS, Orr AL, Orr AG. Astrocytes in selective vulnerability to neurodegenerative disease. Trends Neurosci 2024; 47:289-302. [PMID: 38521710 PMCID: PMC11006581 DOI: 10.1016/j.tins.2024.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/06/2024] [Accepted: 02/26/2024] [Indexed: 03/25/2024]
Abstract
Selective vulnerability of specific brain regions and cell populations is a hallmark of neurodegenerative disorders. Mechanisms of selective vulnerability involve neuronal heterogeneity, functional specializations, and differential sensitivities to stressors and pathogenic factors. In this review we discuss the growing body of literature suggesting that, like neurons, astrocytes are heterogeneous and specialized, respond to and integrate diverse inputs, and induce selective effects on brain function. In disease, astrocytes undergo specific, context-dependent changes that promote different pathogenic trajectories and functional outcomes. We propose that astrocytes contribute to selective vulnerability through maladaptive transitions to context-divergent phenotypes that impair specific brain regions and functions. Further studies on the multifaceted roles of astrocytes in disease may provide new therapeutic approaches to enhance resilience against neurodegenerative disorders.
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Affiliation(s)
- Till S Zimmer
- Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA; Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Adam L Orr
- Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA; Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA; Neuroscience Graduate Program, Weill Cornell Medicine, New York, NY, USA
| | - Anna G Orr
- Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA; Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA; Neuroscience Graduate Program, Weill Cornell Medicine, New York, NY, USA.
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Eisenbaum M, Pearson A, Ortiz C, Koprivica M, Cembran A, Mullan M, Crawford F, Ojo J, Bachmeier C. Repetitive head trauma and apoE4 induce chronic cerebrovascular alterations that impair tau elimination from the brain. Exp Neurol 2024; 374:114702. [PMID: 38301863 PMCID: PMC10922621 DOI: 10.1016/j.expneurol.2024.114702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/25/2024] [Indexed: 02/03/2024]
Abstract
Repetitive mild traumatic brain injuries (r-mTBI) sustained in the military or contact sports have been associated with the accumulation of extracellular tau in the brain, which may contribute to the pathogenesis of neurodegenerative tauopathies. The expression of the apolipoprotein E4 (apoE4) isoform has been associated with higher levels of tau in the brain, and worse clinical outcomes after r-mTBI, though the influence of apoE genotype on extracellular tau dynamics in the brain is poorly understood. We recently demonstrated that extracellular tau can be eliminated across blood-brain barrier (BBB), which is progressively impaired following r-mTBI. The current studies investigated the influence of repetitive mild TBI (r-mTBI) and apoE genotype on the elimination of extracellular solutes from the brain. Following intracortical injection of biotin-labeled tau into humanized apoE-Tr mice, the levels of exogenous tau residing in the brain of apoE4 mice were elevated compared to other isoforms, indicating reduced tau elimination. Additionally, we found exposure to r-mTBI increased tau residence in apoE2 mice, similar to our observations in E2FAD animals. Each of these findings may be the result of diminished tau efflux via LRP1 at the BBB, as LRP1 inhibition significantly reduced tau uptake in endothelial cells and decreased tau transit across an in vitro model of the BBB (basolateral-to-apical). Notably, we showed that injury and apoE status, (particularly apoE4) resulted in chronic alterations in BBB integrity, pericyte coverage, and AQP4 polarization. These aberrations coincided with an atypical reactive astrocytic gene signature indicative of diminished CSF-ISF exchange. Our work found that CSF movement was reduced in the chronic phase following r-mTBI (>18 months post injury) across all apoE genotypes. In summary, we show that apoE genotype strongly influences cerebrovascular homeostasis, which can lead to age-dependent deficiencies in the elimination of toxic proteins from the brain, like tau, particularly in the aftermath of head trauma.
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Affiliation(s)
| | | | | | | | | | | | - Fiona Crawford
- The Roskamp Institute, Sarasota, FL, USA; James A. Haley Veterans' Hospital, Tampa, FL, USA
| | - Joseph Ojo
- The Roskamp Institute, Sarasota, FL, USA
| | - Corbin Bachmeier
- The Roskamp Institute, Sarasota, FL, USA; Bay Pines VA Healthcare System, Bay Pines, FL, USA
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Eisen A, Nedergaard M, Gray E, Kiernan MC. The glymphatic system and Amyotrophic lateral sclerosis. Prog Neurobiol 2024; 234:102571. [PMID: 38266701 DOI: 10.1016/j.pneurobio.2024.102571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/18/2023] [Accepted: 01/15/2024] [Indexed: 01/26/2024]
Abstract
The glymphatic system and the meningeal lymphatic vessels provide a pathway for transport of solutes and clearance of toxic material from the brain. Of specific relevance to ALS, this is applicable for TDP-43 and glutamate, both major elements in disease pathogenesis. Flow is propelled by arterial pulsation, respiration, posture, as well as the positioning and proportion of aquaporin-4 channels (AQP4). Non-REM slow wave sleep is the is key to glymphatic drainage which discontinues during wakefulness. In Parkinson's disease and Alzheimer's disease, sleep impairment is known to predate the development of characteristic clinical features by several years and is associated with progressive accumulation of toxic proteinaceous products. While sleep issues are well described in ALS, consideration of preclinical sleep impairment or the potential of a failing glymphatic system in ALS has rarely been considered. Here we review how the glymphatic system may impact ALS. Preclinical sleep impairment as an unrecognized major risk factor for ALS is considered, while potential therapeutic options to improve glymphatic flow are explored.
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Affiliation(s)
- Andrew Eisen
- Department of Neurology, University of British Columbia, Vancouver, Canada.
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical School and Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Emma Gray
- Department of Neurology, Royal Prince Alfred Hospital and University of Sydney, NSW 2050, Australia
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Xie L, Zhang Y, Hong H, Xu S, Cui L, Wang S, Li J, Liu L, Lin M, Luo X, Li K, Zeng Q, Zhang M, Zhang R, Huang P. Higher intracranial arterial pulsatility is associated with presumed imaging markers of the glymphatic system: An explorative study. Neuroimage 2024; 288:120524. [PMID: 38278428 DOI: 10.1016/j.neuroimage.2024.120524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 01/28/2024] Open
Abstract
BACKGROUND Arterial pulsation has been suggested as a key driver of paravascular cerebrospinal fluid flow, which is the foundation of glymphatic clearance. However, whether intracranial arterial pulsatility is associated with glymphatic markers in humans has not yet been studied. METHODS Seventy-three community participants were enrolled in the study. 4D phase-contrast magnetic resonance imaging (MRI) was used to quantify the hemodynamic parameters including flow pulsatility index (PIflow) and area pulsatility index (PIarea) from 13 major intracerebral arterial segments. Three presumed neuroimaging markers of the glymphatic system were measured: including dilation of perivascular space (PVS), diffusivity along the perivascular space (ALPS), and volume fraction of free water (FW) in white matter. We explored the relationships between PIarea, PIflow, and the presumed glymphatic markers, controlling for related covariates. RESULTS PIflow in the internal carotid artery (ICA) C2 segment (OR, 1.05; 95 % CI, 1.01-1.10, per 0.01 increase in PI) and C4 segment (OR, 1.05; 95 % CI, 1.01-1.09) was positively associated with the dilation of basal ganglia PVS, and PIflow in the ICA C4 segment (OR, 1.06, 95 % CI, 1.02-1.10) was correlated with the dilation of PVS in the white matter. ALPS was associated with PIflow in the basilar artery (β, -0.273, p, 0.046) and PIarea in the ICA C2 (β, -0.239, p, 0.041) and C7 segments (β, -0.238, p, 0.037). CONCLUSIONS Intracranial arterial pulsatility was associated with presumed neuroimaging markers of the glymphatic system, but the results were not consistent across different markers. Further studies are warranted to confirm these findings.
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Affiliation(s)
- Linyun Xie
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Yao Zhang
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Hui Hong
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Shan Xu
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Lei Cui
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Shuyue Wang
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Jixuan Li
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Lingyun Liu
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Miao Lin
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Xiao Luo
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Kaicheng Li
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Qingze Zeng
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Minming Zhang
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Ruiting Zhang
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China
| | - Peiyu Huang
- Department of Radiology, The 2nd Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Shangcheng District, Hangzhou 310009, China.
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Gallina P, Lolli F, Cianti D, Perri F, Porfirio B. Failure of the glymphatic system by increases of jugular resistance as possible link between asthma and dementia. Brain Commun 2024; 6:fcae039. [PMID: 38410621 PMCID: PMC10896477 DOI: 10.1093/braincomms/fcae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 10/16/2023] [Accepted: 02/09/2024] [Indexed: 02/28/2024] Open
Affiliation(s)
- Pasquale Gallina
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, 50134 Florence, Italy
- Careggi University Hospital, 50134 Florence, Italy
| | - Francesco Lolli
- Careggi University Hospital, 50134 Florence, Italy
- Department of Clinical and Experimental Biomedical Sciences ‘Mario Serio’, University of Florence, 50134 Florence, Italy
| | - Duccio Cianti
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, 50134 Florence, Italy
| | | | - Berardino Porfirio
- Department of Clinical and Experimental Biomedical Sciences ‘Mario Serio’, University of Florence, 50134 Florence, Italy
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Szlufik S, Kopeć K, Szleszkowski S, Koziorowski D. Glymphatic System Pathology and Neuroinflammation as Two Risk Factors of Neurodegeneration. Cells 2024; 13:286. [PMID: 38334678 PMCID: PMC10855155 DOI: 10.3390/cells13030286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/26/2024] [Accepted: 02/03/2024] [Indexed: 02/10/2024] Open
Abstract
The key to the effective treatment of neurodegenerative disorders is a thorough understanding of their pathomechanism. Neurodegeneration and neuroinflammation are mutually propelling brain processes. An impairment of glymphatic system function in neurodegeneration contributes to the progression of pathological processes. The question arises as to how neuroinflammation and the glymphatic system are related. This review highlights the direct and indirect influence of these two seemingly independent processes. Protein aggregates, a characteristic feature of neurodegeneration, are correlated with glymphatic clearance and neuroinflammation. Glial cells cannot be overlooked when considering the neuroinflammatory processes. Astrocytes are essential for the effective functioning of the glymphatic system and play a crucial role in the inflammatory responses in the central nervous system. It is imperative to acknowledge the significance of AQP4, a protein that exhibits a high degree of polarization in astrocytes and is crucial for the functioning of the glymphatic system. AQP4 influences inflammatory processes that have not yet been clearly delineated. Another interesting issue is the gut-brain axis and microbiome, which potentially impact the discussed processes. A discussion of the correlation between the functioning of the glymphatic system and neuroinflammation may contribute to exploring the pathomechanism of neurodegeneration.
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Affiliation(s)
- Stanisław Szlufik
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, 02-091 Warszawa, Poland; (K.K.)
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Moëlo C, Quillévéré A, Le Roy L, Timsit S. (S)-roscovitine, a CDK inhibitor, decreases cerebral edema and modulates AQP4 and α1-syntrophin interaction on a pre-clinical model of acute ischemic stroke. Glia 2024; 72:322-337. [PMID: 37828900 DOI: 10.1002/glia.24477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/22/2023] [Accepted: 09/07/2023] [Indexed: 10/14/2023]
Abstract
Cerebral edema is one of the deadliest complications of ischemic stroke for which there is currently no pharmaceutical treatment. Aquaporin-4 (AQP4), a water-channel polarized at the astrocyte endfoot, is known to be highly implicated in cerebral edema. We previously showed in randomized studies that (S)-roscovitine, a cyclin-dependent kinase inhibitor, reduced cerebral edema 48 h after induction of focal transient ischemia, but its mechanisms of action were unclear. In our recent blind randomized study, we confirmed that (S)-roscovitine was able to reduce cerebral edema by 65% at 24 h post-stroke (t test, p = .006). Immunofluorescence analysis of AQP4 distribution in astrocytes revealed that (S)-roscovitine decreased the non-perivascular pool of AQP4 by 53% and drastically increased AQP4 clusters in astrocyte perivascular end-feet (671%, t test p = .005) compared to vehicle. Non-perivascular and clustered AQP4 compartments were negatively correlated (R = -0.78; p < .0001), suggesting a communicating vessels effect between the two compartments. α1-syntrophin, AQP4 anchoring protein, was colocalized with AQP4 in astrocyte endfeet, and this colocalization was maintained in ischemic area as observed on confocal microscopy. Moreover, (S)-roscovitine increased AQP4/α1-syntrophin interaction (40%, MW p = .0083) as quantified by proximity ligation assay. The quantified interaction was negatively correlated with brain edema in both treated and placebo groups (R = -.57; p = .0074). We showed for the first time, that a kinase inhibitor modulated AQP4/α1-syntrophin interaction, and was implicated in the reduction of cerebral edema. These findings suggest that (S)-roscovitine may hold promise as a potential treatment for cerebral edema in ischemic stroke and as modulator of AQP4 function in other neurological diseases.
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Affiliation(s)
- Cloé Moëlo
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
| | - Alicia Quillévéré
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
| | - Lucas Le Roy
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
| | - Serge Timsit
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
- Neurology and Stroke Unit Department, CHRU de Brest, Inserm1078, Université de Bretagne Occidentale, Brest, France
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Lee SY, Chung WS. Astrocytic crosstalk with brain and immune cells in healthy and diseased conditions. Curr Opin Neurobiol 2024; 84:102840. [PMID: 38290370 DOI: 10.1016/j.conb.2024.102840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/04/2023] [Accepted: 01/05/2024] [Indexed: 02/01/2024]
Abstract
Astrocytes interact with various cell types, including neurons, vascular cells, microglia, and peripheral immune cells. These interactions are crucial for regulating normal brain functions as well as modulating neuroinflammation in pathological conditions. Recent transcriptomic and proteomic studies have identified critical molecules involved in astrocytic crosstalk with other cells, shedding light on their roles in maintaining brain homeostasis in both healthy and diseased conditions. Astrocytes perform these various roles through either direct or indirect physical associations with neuronal synapses and vasculature. Furthermore, astrocytes can communicate with other immune cells, such as microglia, T cells, and natural killer cells, through secreted molecules during neuroinflammation. In this review, we discuss the critical molecular basis of this astrocytic crosstalk and the underlying mechanisms of astrocyte communication with other cells. We propose that astrocytes function as a central hub in inter-connecting neurons, vasculatures, and immune cells in healthy and diseased brains.
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Affiliation(s)
- Se Young Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea. https://twitter.com/SYLee_neuro
| | - Won-Suk Chung
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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Federau C. Clinical Interpretation of Intravoxel Incoherent Motion Perfusion Imaging in the Brain. Magn Reson Imaging Clin N Am 2024; 32:85-92. [PMID: 38007285 DOI: 10.1016/j.mric.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Intravoxel incoherent motion (IVIM) perfusion imaging extracts information on blood motion in biological tissue from diffusion-weighted MR images. The method is attractive from a clinical stand point, because it measures in essence local quantitative perfusion, without intravenous contrast injection. Currently, the clinical interpretation of IVIM perfusion maps focuses on the IVIM perfusion fraction maps, but improvements in image quality of the IVIM pseudo-diffusion maps, using advanced postprocessing tools involving artificial intelligence, could lead to an increased interest in this parameters, as it could provide additional local perfusion information in the clinical setting, not otherwise available with other perfusion techniques.
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Affiliation(s)
- Christian Federau
- AI Medical AG, Goldhaldenstr 22a, Zollikon 8702, Switzerland; University of Zürich, Zürich, Switzerland.
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12
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Avola R, Furnari AG, Graziano ACE, Russo A, Cardile V. Management of the Brain: Essential Oils as Promising Neuroinflammation Modulator in Neurodegenerative Diseases. Antioxidants (Basel) 2024; 13:178. [PMID: 38397776 PMCID: PMC10886016 DOI: 10.3390/antiox13020178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
Neuroinflammation, a pivotal factor in the pathogenesis of various brain disorders, including neurodegenerative diseases, has become a focal point for therapeutic exploration. This review highlights neuroinflammatory mechanisms that hallmark neurodegenerative diseases and the potential benefits of essential oils in counteracting neuroinflammation and oxidative stress, thereby offering a novel strategy for managing and mitigating the impact of various brain disorders. Essential oils, derived from aromatic plants, have emerged as versatile compounds with a myriad of health benefits. Essential oils exhibit robust antioxidant activity, serving as scavengers of free radicals and contributing to cellular defense against oxidative stress. Furthermore, essential oils showcase anti-inflammatory properties, modulating immune responses and mitigating inflammatory processes implicated in various chronic diseases. The intricate mechanisms by which essential oils and phytomolecules exert their anti-inflammatory and antioxidant effects were explored, shedding light on their multifaceted properties. Notably, we discussed their ability to modulate diverse pathways crucial in maintaining oxidative homeostasis and suppressing inflammatory responses, and their capacity to rescue cognitive deficits observed in preclinical models of neurotoxicity and neurodegenerative diseases.
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Affiliation(s)
- Rosanna Avola
- Faculty of Medicine and Surgery, University of Enna “Kore”, 94100 Enna, Italy;
| | | | | | - Alessandra Russo
- Department of Drug and Health Sciences, University of Catania, 95123 Catania, Italy;
| | - Venera Cardile
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy;
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Lapshina KV, Ekimova IV. Aquaporin-4 and Parkinson's Disease. Int J Mol Sci 2024; 25:1672. [PMID: 38338949 PMCID: PMC10855351 DOI: 10.3390/ijms25031672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/15/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
The water-selective channel aquaporin-4 (AQP4) is implicated in water homeostasis and the functioning of the glymphatic system, which eliminates various metabolites from the brain tissue, including amyloidogenic proteins. Misfolding of the α-synuclein protein and its post-translational modifications play a crucial role in the development of Parkinson's disease (PD) and other synucleopathies, leading to the formation of cytotoxic oligomers and aggregates that cause neurodegeneration. Human and animal studies have shown an interconnection between AQP4 dysfunction and α-synuclein accumulation; however, the specific role of AQP4 in these mechanisms remains unclear. This review summarizes the current knowledge on the role of AQP4 dysfunction in the progression of α-synuclein pathology, considering the possible effects of AQP4 dysregulation on brain molecular mechanisms that can impact α-synuclein modification, accumulation and aggregation. It also highlights future directions that can help study the role of AQP4 in the functioning of the protective mechanisms of the brain during the development of PD and other neurodegenerative diseases.
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Affiliation(s)
- Ksenia V. Lapshina
- Laboratory of Comparative Thermophysiology, Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 194223 Saint Petersburg, Russia;
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14
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Hoglund Z, Ruiz-Uribe N, del Sastre E, Woost B, Bailey J, Hyman BT, Zwang T, Bennett RE. Brain Vasculature Accumulates Tau and Is Spatially Related to Tau Tangle Pathology in Alzheimer's Disease. bioRxiv 2024:2024.01.27.577088. [PMID: 38328111 PMCID: PMC10849642 DOI: 10.1101/2024.01.27.577088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Insoluble pathogenic proteins accumulate along blood vessels in conditions of cerebral amyloid angiopathy (CAA), exerting a toxic effect on vascular cells and impacting cerebral homeostasis. In this work we provide new evidence from three-dimensional human brain histology that tau protein, the main component of neurofibrillary tangles, can similarly accumulate along brain vascular segments. We quantitatively assessed n=6 Alzheimer's disease (AD), and n=6 normal aging control brains and saw that tau-positive blood vessel segments were present in all AD cases. Tau-positive vessels are enriched for tau at levels higher than the surrounding tissue and appear to affect arterioles across cortical layers (I-V). Further, vessels isolated from these AD tissues were enriched for N-terminal tau and tau phosphorylated at T181 and T217. Importantly, tau-positive vessels are associated with local areas of increased tau neurofibrillary tangles. This suggests that accumulation of tau around blood vessels may reflect a local clearance failure. In sum, these data indicate tau, like amyloid beta, accumulates along blood vessels and may exert a significant influence on vasculature in the setting of AD.
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Affiliation(s)
- Zachary Hoglund
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Nancy Ruiz-Uribe
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Eric del Sastre
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Benjamin Woost
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Joshua Bailey
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Bradley T. Hyman
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Theodore Zwang
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Rachel E. Bennett
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
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15
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Kameda H, Kinota N, Kato D, Fujii T, Harada T, Komaki Y, Sugimori H, Onodera T, Tomiyasu M, Obata T, Kudo K. Magnetic Resonance Water Tracer Imaging Using 17 O-Labeled Water. Invest Radiol 2024; 59:92-103. [PMID: 37707860 DOI: 10.1097/rli.0000000000001021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
ABSTRACT Magnetic resonance imaging (MRI) is a crucial imaging technique for visualizing water in living organisms. Besides proton MRI, which is widely available and enables direct visualization of intrinsic water distribution and dynamics in various environments, MR-WTI (MR water tracer imaging) using 17 O-labeled water has been developed, benefiting from the many advancements in MRI software and hardware that have substantially improved the signal-to-noise ratio and made possible faster imaging. This cutting-edge technique allows the generation of novel and valuable images for clinical use. This review elucidates the studies related to MRI water tracer techniques centered around 17 O-labeled water, explaining the fundamental principles of imaging and providing clinical application examples. Anticipating continued progress in studies involving isotope-labeled water, this review is expected to contribute to elucidating the pathophysiology of various diseases related to water dynamics abnormalities and establishing novel imaging diagnostic methods for associated diseases.
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Affiliation(s)
- Hiroyuki Kameda
- From the Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, Japan (H.K., N.K., D.K., T.F., T.H., K.K.); Department of Radiology, Faculty of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan (H.K.); Department of Diagnostic Imaging, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan (N.K., D.K., T.F., T.H., K.K.); Live Animal Imaging Center, Central Institute for Experimental Animals, Kanagawa, Japan (Y.K.); Faculty of Health Sciences, Hokkaido University, Sapporo, Japan (H.S.); Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan (T. Onodera); Department of Molecular Imaging and Theranostics, National Institutes for Quantum Science and Technology, Chiba, Japan (M.T., T. Obata); and Global Center for Biomedical Science and Engineering, Faculty of Medicine, Hokkaido University, Sapporo, Japan (T.H., K.K.)
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16
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Plá V, Bitsika S, Giannetto MJ, Ladron-de-Guevara A, Gahn-Martinez D, Mori Y, Nedergaard M, Møllgård K. Structural characterization of SLYM-a 4th meningeal membrane. Fluids Barriers CNS 2023; 20:93. [PMID: 38098084 PMCID: PMC10722698 DOI: 10.1186/s12987-023-00500-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023] Open
Abstract
Traditionally, the meninges are described as 3 distinct layers, dura, arachnoid and pia. Yet, the classification of the connective meningeal membranes surrounding the brain is based on postmortem macroscopic examination. Ultrastructural and single cell transcriptome analyses have documented that the 3 meningeal layers can be subdivided into several distinct layers based on cellular characteristics. We here re-examined the existence of a 4th meningeal membrane, Subarachnoid Lymphatic-like Membrane or SLYM in Prox1-eGFP reporter mice. Imaging of freshly resected whole brains showed that SLYM covers the entire brain and brain stem and forms a roof shielding the subarachnoid cerebrospinal fluid (CSF)-filled cisterns and the pia-adjacent vasculature. Thus, SLYM is strategically positioned to facilitate periarterial influx of freshly produced CSF and thereby support unidirectional glymphatic CSF transport. Histological analysis showed that, in spinal cord and parts of dorsal cortex, SLYM fused with the arachnoid barrier layer, while in the basal brain stem typically formed a 1-3 cell layered membrane subdividing the subarachnoid space into two compartments. However, great care should be taken when interpreting the organization of the delicate leptomeningeal membranes in tissue sections. We show that hyperosmotic fixatives dehydrate the tissue with the risk of shrinkage and dislocation of these fragile membranes in postmortem preparations.
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Affiliation(s)
- Virginia Plá
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Styliani Bitsika
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Michael J Giannetto
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Antonio Ladron-de-Guevara
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Daniel Gahn-Martinez
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Yuki Mori
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Maiken Nedergaard
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark.
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.
| | - Kjeld Møllgård
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark.
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17
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Shih NC, Barisano G, Lincoln KD, Mack WJ, Sepehrband F, Choupan J. Effects of sleep on brain perivascular space in a cognitively healthy population. Sleep Med 2023; 111:170-179. [PMID: 37782994 PMCID: PMC10591884 DOI: 10.1016/j.sleep.2023.09.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/20/2023] [Accepted: 09/23/2023] [Indexed: 10/04/2023]
Abstract
The magnetic resonance imaging (MRI) visible perivascular space (PVS) reportedly clears amyloid-β and metabolic waste during sleep. Previous studies reported an association between sleep and the PVS in small vessel disease, traumatic brain injury, and Alzheimer's disease. However, this relationship in a healthy cohort is still unclear. Here, we used the Human Connectome Project Aging dataset to analyze the relationship between sleep and the PVS in cognitively healthy adults across the aging continuum. We measured sleep parameters using the self-reported Pittsburgh Sleep Quality Index questionnaire. We found that older adults who had better sleep quality and sleep efficiency presented with a larger PVS volume fraction in the basal ganglia (BG). However, sleep measures were not associated with PVS volume fraction in the centrum semiovale (CSO). In addition, we found that body mass index (BMI) influenced the BG-PVS across middle-aged and older participants. In the entire cognitively healthy cohort, the effect of sleep quality on PVS volume fraction was mediated by BMI. However, BMI did not influence this effect in the older cohort. Furthermore, there are significant differences in PVS volume fraction across racial/ethnic cohorts. In summary, the effect of sleep on the PVS volume alteration was different in the middle-aged adults and older adults.
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Affiliation(s)
- Nien-Chu Shih
- Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Giuseppe Barisano
- Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Department of Neurosurgery, Stanford University, Palo Alto, CA, USA
| | - Karen D Lincoln
- Program in Public Health, Department of Environmental and Occupational Health, University of California, Irvine, CA, USA
| | - Wendy J Mack
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Farshid Sepehrband
- Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jeiran Choupan
- Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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18
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Plá V, Bitsika S, Giannetto M, Ladron-de-Guevara A, Gahn-Martinez D, Mori Y, Nedergaard M, Møllgård K. Structural characterization of SLYM - a 4th meningeal membrane. Res Sq 2023:rs.3.rs-3500436. [PMID: 37961391 PMCID: PMC10635397 DOI: 10.21203/rs.3.rs-3500436/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Traditionally, the meninges are described as 3 distinct layers, dura, arachnoid and pia. Yet, the classification of the connective meningeal membranes surrounding the brain is based on postmortem macroscopic examination. Ultrastructural and single cell transcriptome analyses have documented that the 3 meningeal layers can be subdivided into several distinct layers based on cellular characteristics. We here re-examined the existence of a 4th meningeal membrane, Subarachnoid Lymphatic-like Membrane or SLYM in Prox1-eGFP reporter mice. Imaging of freshly resected whole brains showed that SLYM covers the entire brain and brain stem and forms a roof shielding the subarachnoid cerebrospinal fluid (CSF)-filled cisterns and the pia-adjacent vasculature. Thus, SLYM is strategically positioned to facilitate periarterial influx of freshly produced CSF and thereby support unidirectional glymphatic CSF transport. Histological analysis showed that, in spinal cord and parts of dorsal cortex, SLYM fused with the arachnoid barrier layer, while in the basal brain stem typically formed a 1-3 cell layered membrane subdividing the subarachnoid space into two compartments. However, great care should be taken when interpreting the organization of the delicate leptomeningeal membranes in tissue sections. We show that hyperosmotic fixatives dehydrate the tissue with the risk of shrinkage and dislocation of these fragile membranes in postmortem preparations.
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19
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Plá V, Bitsika S, Giannetto M, Ladron-de-Guevara A, Gahn-Martinez D, Mori Y, Nedergaard M, Møllgård K. Structural characterization of SLYM - a 4 th meningeal membrane. bioRxiv 2023:2023.10.20.563351. [PMID: 37961461 PMCID: PMC10634706 DOI: 10.1101/2023.10.20.563351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Traditionally, the meninges are described as 3 distinct layers, dura, arachnoid and pia. Yet, the classification of the connective meningeal membranes surrounding the brain is based on postmortem macroscopic examination. Ultrastructural and single cell transcriptome analyses have documented that the 3 meningeal layers can be subdivided into several distinct layers based on cellular characteristics. We here re-examined the existence of a 4 th meningeal membrane, S ubarachnoid Ly mphatic-like M embrane or SLYM in Prox1-eGFP reporter mice. Imaging of freshly resected whole brains showed that SLYM covers the entire brain and brain stem and forms a roof shielding the subarachnoid cerebrospinal fluid (CSF)-filled cisterns and the pia-adjacent vasculature. Thus, SLYM is strategically positioned to facilitate periarterial influx of freshly produced CSF and thereby support unidirectional glymphatic CSF transport. Histological analysis showed that, in spinal cord and parts of dorsal cortex, SLYM fused with the arachnoid barrier layer, while in the basal brain stem typically formed a 1-3 cell layered membrane subdividing the subarachnoid space into two compartments. However, great care should be taken when interpreting the organization of the delicate leptomeningeal membranes in tissue sections. We show that hyperosmotic fixatives dehydrate the tissue with the risk of shrinkage and dislocation of these fragile membranes in postmortem preparations.
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20
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Zhu Y, Wang G, Kolluru C, Gu Y, Gao H, Zhang J, Wang Y, Wilson DL, Zhu X, Flask CA, Yu X. Transport pathways and kinetics of cerebrospinal fluid tracers in mouse brain observed by dynamic contrast-enhanced MRI. Sci Rep 2023; 13:13882. [PMID: 37620371 PMCID: PMC10449788 DOI: 10.1038/s41598-023-40896-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023] Open
Abstract
Recent studies have suggested the glymphatic system as a key mechanism of waste removal in the brain. Dynamic contrast-enhanced MRI (DCE-MRI) using intracisternally administered contrast agents is a promising tool for assessing glymphatic function in the whole brain. In this study, we evaluated the transport kinetics and distribution of three MRI contrast agents with vastly different molecular sizes in mice. Our results demonstrate that oxygen-17 enriched water (H217O), which has direct access to parenchymal tissues via aquaporin-4 water channels, exhibited significantly faster and more extensive transport compared to the two gadolinium-based contrast agents (Gd-DTPA and GadoSpin). Time-lagged correlation and clustering analyses also revealed different transport pathways for Gd-DTPA and H217O. Furthermore, there were significant differences in transport kinetics of the three contrast agents to the lateral ventricles, reflecting the differences in forces that drive solute transport in the brain. These findings suggest the size-dependent transport pathways and kinetics of intracisternally administered contrast agents and the potential of DCE-MRI for assessing multiple aspects of solute transport in the glymphatic system.
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Affiliation(s)
- Yuran Zhu
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Guanhua Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Chaitanya Kolluru
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Huiyun Gao
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, USA
- Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jing Zhang
- Department of Biostatistics, Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Yunmei Wang
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, USA
- Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - David L Wilson
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
- Department of Radiology, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Xiaofeng Zhu
- Department of Biostatistics, Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Chris A Flask
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
- Department of Radiology, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
- Department of Radiology, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
- Department of Physiology and Biophysics, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
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21
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Hayden MR. Brain Endothelial Cells Play a Central Role in the Development of Enlarged Perivascular Spaces in the Metabolic Syndrome. Medicina (Kaunas) 2023; 59:1124. [PMID: 37374328 DOI: 10.3390/medicina59061124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 05/24/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023]
Abstract
Brain capillary endothelial cell(s) (BECs) have numerous functions, including their semipermeable interface-barrier (transfer and diffusion of solutes), trophic (metabolic homeostasis), tonic (vascular hemodynamics), and trafficking (vascular permeability, coagulation, and leukocyte extravasation) functions to provide brain homeostasis. BECs also serve as the brain's sentinel cell of the innate immune system and are capable of antigen presentation. In metabolic syndrome (MetS), there are two regions resulting in the proinflammatory signaling of BECs, namely visceral adipose tissue depots supplying excessive peripheral cytokines/chemokines (pCCs) and gut microbiota dysbiotic regions supplying excessive soluble lipopolysaccharide (sLPS), small LPS-enriched extracellular vesicle exosomes (lpsEVexos), and pCCs. This dual signaling of BECs at their receptor sites results in BEC activation and dysfunction (BECact/dys) and neuroinflammation. sLPS and lpsEVexos signal BECs' toll-like receptor 4, which then signals translocated nuclear factor kappa B (NFkB). Translocated NFkB promotes the synthesis and secretion of BEC proinflammatory cytokines and chemokines. Specifically, the chemokine CCL5 (RANTES) is capable of attracting microglia cells to BECs. BEC neuroinflammation activates perivascular space(s) (PVS) resident macrophages. Excessive phagocytosis by reactive resident PVS macrophages results in a stagnation-like obstruction, which along with increased capillary permeability due to BECact/dys could expand the fluid volume within the PVS to result in enlarged PVS (EPVS). Importantly, this remodeling may result in pre- and post-capillary EPVS that would contribute to their identification on T2-weighted MRI, which are considered to be biomarkers for cerebral small vessel disease.
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Affiliation(s)
- Melvin R Hayden
- Department of Internal Medicine, Endocrinology Diabetes and Metabolism, Diabetes and Cardiovascular Disease Center, University of Missouri School of Medicine, One Hospital Drive, Columbia, MO 65211, USA
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Barmpagiannos K, Theotokis P, Petratos S, Pagnin M, Einstein O, Kesidou E, Boziki M, Artemiadis A, Bakirtzis C, Grigoriadis N. The Diversity of Astrocyte Activation during Multiple Sclerosis: Potential Cellular Targets for Novel Disease Modifying Therapeutics. Healthcare (Basel) 2023; 11:healthcare11111585. [PMID: 37297725 DOI: 10.3390/healthcare11111585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/19/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
Neuroglial cells, and especially astrocytes, constitute the most varied group of central nervous system (CNS) cells, displaying substantial diversity and plasticity during development and in disease states. The morphological changes exhibited by astrocytes during the acute and chronic stages following CNS injury can be characterized more precisely as a dynamic continuum of astrocytic reactivity. Different subpopulations of reactive astrocytes may be ascribed to stages of degenerative progression through their direct pathogenic influence upon neurons, neuroglia, the blood-brain barrier, and infiltrating immune cells. Multiple sclerosis (MS) constitutes an autoimmune demyelinating disease of the CNS. Despite the previously held notion that reactive astrocytes purely form the structured glial scar in MS plaques, their continued multifaceted participation in neuroinflammatory outcomes and oligodendrocyte and neuronal function during chronicity, suggest that they may be an integral cell type that can govern the pathophysiology of MS. From a therapeutic-oriented perspective, astrocytes could serve as key players to limit MS progression, once the integral astrocyte-MS relationship is accurately identified. This review aims toward delineating the current knowledge, which is mainly focused on immunomodulatory therapies of the relapsing-remitting form, while shedding light on uncharted approaches of astrocyte-specific therapies that could constitute novel, innovative applications once the role of specific subgroups in disease pathogenesis is clarified.
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Affiliation(s)
- Konstantinos Barmpagiannos
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, Aristotle University of Thessaloniki, 54621 Thessaloniki, Greece
| | - Paschalis Theotokis
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, Aristotle University of Thessaloniki, 54621 Thessaloniki, Greece
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Maurice Pagnin
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Ofira Einstein
- Department of Physical Therapy, Faculty of Health Sciences, Ariel University, Ariel 40700, Israel
| | - Evangelia Kesidou
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, Aristotle University of Thessaloniki, 54621 Thessaloniki, Greece
| | - Marina Boziki
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, Aristotle University of Thessaloniki, 54621 Thessaloniki, Greece
| | | | - Christos Bakirtzis
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, Aristotle University of Thessaloniki, 54621 Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- Laboratory of Experimental Neurology and Neuroimmunology, Second Department of Neurology, Aristotle University of Thessaloniki, 54621 Thessaloniki, Greece
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23
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Gao H, Findeis EL, Culmone L, Powell B, Landschoot-Ward J, Zacharek A, Wu T, Lu M, Chopp M, Venkat P. Early therapeutic effects of an Angiopoietin-1 mimetic peptide in middle-aged rats with vascular dementia. Front Aging Neurosci 2023; 15:1180913. [PMID: 37304071 PMCID: PMC10248134 DOI: 10.3389/fnagi.2023.1180913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/04/2023] [Indexed: 06/13/2023] Open
Abstract
Background Vascular Dementia (VaD) refers to dementia caused by cerebrovascular disease and/or reduced blood flow to the brain and is the second most common form of dementia after Alzheimer's disease. We previously found that in middle-aged rats subjected to a multiple microinfarction (MMI) model of VaD, treatment with AV-001, a Tie2 receptor agonist, significantly improves short-term memory, long-term memory, as well as improves preference for social novelty compared to control MMI rats. In this study, we tested the early therapeutic effects of AV-001 on inflammation and glymphatic function in rats subjected to VaD. Methods Male, middle-aged Wistar rats (10-12 m), subjected to MMI, were randomly assigned to MMI and MMI + AV-001 treatment groups. A sham group was included as reference group. MMI was induced by injecting 800 ± 200, 70-100 μm sized, cholesterol crystals into the internal carotid artery. Animals were treated with AV-001 (1 μg/Kg, i.p.) once daily starting at 24 h after MMI. At 14 days after MMI, inflammatory factor expression was evaluated in cerebrospinal fluid (CSF) and brain. Immunostaining was used to evaluate white matter integrity, perivascular space (PVS) and perivascular Aquaporin-4 (AQP4) expression in the brain. An additional set of rats were prepared to test glymphatic function. At 14 days after MMI, 50 μL of 1% Tetramethylrhodamine (3 kD) and FITC conjugated dextran (500 kD) at 1:1 ratio were injected into the CSF. Rats (4-6/group/time point) were sacrificed at 30 min, 3 h, and 6 h from the start of tracer infusion, and brain coronal sections were imaged using a Laser scanning confocal microscope to evaluate tracer intensities in the brain. Result Treatment of MMI with AV-001 significantly improves white matter integrity in the corpus callosum at 14 days after MMI. MMI induces significant dilation of the PVS, reduces AQP4 expression and impairs glymphatic function compared to Sham rats. AV-001 treatment significantly reduces PVS, increases perivascular AQP4 expression and improves glymphatic function compared to MMI rats. MMI significantly increases, while AV-001 significantly decreases the expression of inflammatory factors (tumor necrosis factor-α (TNF-α), chemokine ligand 9) and anti-angiogenic factors (endostatin, plasminogen activator inhibitor-1, P-selectin) in CSF. MMI significantly increases, while AV-001 significantly reduces brain tissue expression of endostatin, thrombin, TNF-α, PAI-1, CXCL9, and interleukin-6 (IL-6). Conclusion AV-001 treatment of MMI significantly reduces PVS dilation and increases perivascular AQP4 expression which may contribute to improved glymphatic function compared to MMI rats. AV-001 treatment significantly reduces inflammatory factor expression in the CSF and brain which may contribute to AV-001 treatment induced improvement in white matter integrity and cognitive function.
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Affiliation(s)
- Huanjia Gao
- Department of Neurology, Henry Ford Health, Detroit, MI, United States
| | | | - Lauren Culmone
- Department of Neurology, Henry Ford Health, Detroit, MI, United States
| | - Brianna Powell
- Department of Neurology, Henry Ford Health, Detroit, MI, United States
| | | | - Alex Zacharek
- Department of Neurology, Henry Ford Health, Detroit, MI, United States
| | - Trueman Wu
- Public Health Sciences, Henry Ford Health, Detroit, MI, United States
| | - Mei Lu
- Public Health Sciences, Henry Ford Health, Detroit, MI, United States
| | - Michael Chopp
- Department of Neurology, Henry Ford Health, Detroit, MI, United States
- Department of Physics, Oakland University, Rochester, MI, United States
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Poornima Venkat
- Department of Neurology, Henry Ford Health, Detroit, MI, United States
- Department of Physiology, Michigan State University, East Lansing, MI, United States
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Yamada K. Multifaceted Roles of Aquaporins in the Pathogenesis of Alzheimer’s Disease. Int J Mol Sci 2023; 24:ijms24076528. [PMID: 37047501 PMCID: PMC10095057 DOI: 10.3390/ijms24076528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/29/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
The central nervous system is highly dependent on water, and disturbances in water homeostasis can have a significant impact on its normal functions. The regulation of water balance is, at least in part, carried out via specialized water channels called aquaporins. In the central nervous system, two major aquaporins (AQPs), AQP1 and AQP4, and their potential involvements have been long implicated in the pathophysiology of many brain disorders such as brain edema and Neuromyelitis optica. In addition to these diseases, there is growing attention to the involvement of AQPs in the removal of waste products in Alzheimer’s disease (AD). This indicates that targeting fluid homeostasis is a novel and attractive approach for AD. This review article aims to summarize recent knowledge on the pathological implications of AQPs in AD, discussing unsolved questions and future prospects.
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Affiliation(s)
- Kaoru Yamada
- Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
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