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Shlobin NA, Staple BL, Sclafani M, Harter DH. The Glymphatic System and Subarachnoid Lymphatic-Like Membrane: Recent Developments in Cerebrospinal Fluid Research. World Neurosurg 2024; 190:147-156. [PMID: 39002777 DOI: 10.1016/j.wneu.2024.07.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 07/05/2024] [Accepted: 07/06/2024] [Indexed: 07/15/2024]
Abstract
BACKGROUND Cerebrospinal fluid (CSF) circulates throughout the ventricles, cranial and spinal subarachnoid spaces, and central spinal cord canal. CSF protects the central nervous system through mechanical cushioning, regulation of intracranial pressure, regulation of metabolic homeostasis, and provision of nutrients. Recently, investigators have characterized the glial-lymphatic (glymphatic) system, the analog of the lymphatic system in the central nervous system, and described a fourth meningeal layer; the subarachnoid lymphatic-like membrane (SLYM)relevant to the CSF. METHODS A narrative review was conducted. RESULTS In this review, we summarize these advances. We describe the development of the original model, controversies, a revised model, and a new conceptual framework. We characterize the biological functions, influence of sleep-wake cycles, and effect of aging with relevance to the glymphatic system. We highlight the role of the glymphatic system in Alzheimer's disease, idiopathic normal pressure hydrocephalus, ischemic stroke, subarachnoid hemorrhage, and traumatic brain injury. Next, we characterize the structure and role of the SLYM. Finally, we explore the relevance of the glymphatic system and SLYM to neurosurgery. CONCLUSIONS This manuscript will inform clinicians and scientists regarding preclinical and translational advances in the understanding of the structure, dynamics, and function of the CSF.
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Affiliation(s)
- Nathan A Shlobin
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
| | - Brandon L Staple
- College of Medicine, University of Nebraska, Omaha, Nebraska, USA
| | | | - David H Harter
- Department of Neurosurgery, NYU Langone, New York, New York, USA
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Zarate SM, Kirabo A, Hinton AO, Santisteban MM. Neuroimmunology of Cardiovascular Disease. Curr Hypertens Rep 2024; 26:339-347. [PMID: 38613621 PMCID: PMC11199253 DOI: 10.1007/s11906-024-01301-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2024] [Indexed: 04/15/2024]
Abstract
PURPOSE OF REVIEW Cardiovascular disease (CVD) is a leading cause of death and chronic disability worldwide. Yet, despite extensive intervention strategies the number of persons affected by CVD continues to rise. Thus, there is great interest in unveiling novel mechanisms that may lead to new treatments. Considering this dilemma, recent focus has turned to the neuroimmune mechanisms involved in CVD pathology leading to a deeper understanding of the brain's involvement in disease pathology. This review provides an overview of new and salient findings regarding the neuroimmune mechanisms that contribute to CVD. RECENT FINDINGS The brain contains neuroimmune niches comprised of glia in the parenchyma and immune cells at the brain's borders, and there is strong evidence that these neuroimmune niches are important in both health and disease. Mechanistic studies suggest that the activation of glia and immune cells in these niches modulates CVD progression in hypertension and heart failure and contributes to the inevitable end-organ damage to the brain. This review provides evidence supporting the role of neuroimmune niches in CVD progression. However, additional research is needed to understand the effects of prolonged neuroimmune activation on brain function.
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Affiliation(s)
- Sara M Zarate
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, USA
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, USA
- Vanderbilt Center for Immunobiology, Nashville, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Nashville, USA
- Vanderbilt Institute for Global Health, Nashville, USA
| | - Antentor O Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, USA
| | - Monica M Santisteban
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, USA.
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Nashville, USA.
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, USA.
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3
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Shu K, Fu YC, Huang M, Cai Z, Ni GF, Huang XY, Song JW, Ye XJ, Cui SH, Zhou YJ, Han L, Wu P, Yan ZH, Liu K. Altered Brain Glymphatic Function at Diffusion-Tensor MRI in Pre-cirrhotic Metabolic Dysfunction-Associated Fatty Liver Disease. Acad Radiol 2024:S1076-6332(24)00381-7. [PMID: 38955593 DOI: 10.1016/j.acra.2024.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 05/26/2024] [Accepted: 06/17/2024] [Indexed: 07/04/2024]
Abstract
RATIONALE AND OBJECTIVES To evaluate glymphatic function changes and their relationships with clinical features in patients with metabolic dysfunction-associated fatty liver disease (MAFLD), thereby facilitating early intervention before this disease progresses to cirrhosis. MATERIALS AND METHODS A cross-sectional cohort of 46 pre-cirrhotic MAFLD patients and 30 age-, sex-, and education-matched controls was enrolled, with diffusion-tensor imaging (DTI) data, laboratory and neurocognitive scores collected. The DTI analysis along the perivascular space (DTI-ALPS) index was computed for qualifying glymphatic function. Generalized linear model and partial correlation analyses were applied to evaluate relationships between the ALPS index and clinical variables. RESULTS MAFLD group exhibited a decreased ALPS index and increased diffusivity along the y-axis in the projection fiber compared to the controls. The altered ALPS index was associated with clock drawing test (CDT) score (3.931 [0.914, 6.947], P = 0.011) and was correlated with diastolic pressure level (r = -0.315, P = 0.033) in MAFLD group. The relationships of ALPS index with CDT score (6.263 [2.069, 10.458], P = 0.003) and diastolic pressure level (r = -0.518, P = 0.014) remained in the MAFLD with metabolic syndrome (MetS) group. Furthermore, the ALPS index was even associated with Auditory Verbal Learning Test-Immediate recall score (-23.853 [-45.417, -2.289], P = 0.030) in MAFLD with MetS group. CONCLUSION MAFLD patients may have a glymphatic dysfunction prior to cirrhosis, and this alteration may be related to cognition and diastolic pressure. Glymphatic dysfunction has a more severe impact on cognition when MAFLD patient is accompanied by MetS.
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Affiliation(s)
- Kun Shu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Yu-Chuan Fu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Mei Huang
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Zheng Cai
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Ge-Fei Ni
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Xiao-Yan Huang
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Jia-Wen Song
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Xin-Jian Ye
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Shi-Han Cui
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Yong-Jin Zhou
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Lu Han
- Philips Healthcare, Shanghai, China.
| | - Peng Wu
- Philips Healthcare, Shanghai, China.
| | - Zhi-Han Yan
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Kun Liu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
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4
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Brendstrup-Brix K, Ulv Larsen SM, Lee HH, Knudsen GM. Perivascular space diffusivity and brain microstructural measures are associated with circadian time and sleep quality. J Sleep Res 2024:e14226. [PMID: 38676409 DOI: 10.1111/jsr.14226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 04/04/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024]
Abstract
The glymphatic system is centred around brain cerebrospinal fluid flow and is enhanced during sleep, and the synaptic homeostasis hypothesis proposes that sleep acts on brain microstructure by selective synaptic downscaling. While so far primarily studied in animals, we here examine in humans if brain diffusivity and microstructure is related to time of day, sleep quality and cognitive performance. We use diffusion weighted images from 916 young healthy individuals, aged between 22 and 37 years, collected as part of the Human Connectome Project to assess diffusion tensor image analysis along the perivascular space index, white matter fractional anisotropy, intra-neurite volume fraction and extra-neurite mean diffusivity. Next, we examine if these measures are associated with circadian time of acquisition, the Pittsburgh Sleep Quality Index (high scores correspond to low sleep quality) and age-adjusted cognitive function total composite score. Consistent with expectations, we find that diffusion tensor image analysis along the perivascular space index and orbitofrontal grey matter extra-neurite mean diffusivity are negatively and white matter fractional anisotropy positively correlated with circadian time. Further, we find that grey matter intra-neurite volume fraction correlates positively with Pittsburgh Sleep Quality Index, and that this correlation is driven by sleep duration. Finally, we find positive correlations between grey matter intra-neurite volume fraction and cognitive function total composite score, as well as negative interaction effects between cognitive function total composite score and Pittsburgh Sleep Quality Index on grey matter intra-neurite volume fraction. Our findings propose that perivascular flow is under circadian control and that sleep downregulates the intra-neurite volume in healthy adults with positive impact on cognitive function.
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Affiliation(s)
- Kristoffer Brendstrup-Brix
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sara Marie Ulv Larsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hong-Hsi Lee
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Abstract
The brain is a complex organ, fundamentally changing across the day to perform basic functions like sleep, thought, and regulating whole-body physiology. This requires a complex symphony of nutrients, hormones, ions, neurotransmitters and more to be properly distributed across the brain to maintain homeostasis throughout 24 hours. These solutes are distributed both by the blood and by cerebrospinal fluid. Cerebrospinal fluid contents are distinct from the general circulation because of regulation at brain barriers including the choroid plexus, glymphatic system, and blood-brain barrier. In this review, we discuss the overlapping circadian (≈24-hour) rhythms in brain fluid biology and at the brain barriers. Our goal is for the reader to gain both a fundamental understanding of brain barriers alongside an understanding of the interactions between these fluids and the circadian timing system. Ultimately, this review will provide new insight into how alterations in these finely tuned clocks may lead to pathology.
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Affiliation(s)
- Velia S Vizcarra
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Ryann M Fame
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
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Dong R, Han Y, Lv P, Jiang L, Wang Z, Peng L, Liu S, Ma Z, Xia T, Zhang B, Gu X. Long-term isoflurane anesthesia induces cognitive deficits via AQP4 depolarization mediated blunted glymphatic inflammatory proteins clearance. J Cereb Blood Flow Metab 2024:271678X241237073. [PMID: 38443763 DOI: 10.1177/0271678x241237073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Perioperative neurocognitive disorders (PND) refer to cognitive deterioration that occurs after surgery or anesthesia. Prolonged isoflurane exposure has potential neurotoxicity and induces PND, but the mechanism is unclear. The glymphatic system clears harmful metabolic waste from the brain. This study sought to unveil the functions of glymphatic system in PND and explore the underlying molecular mechanisms. The PND mice model was established by long term isoflurane anesthesia. The glymphatic function was assessed by multiple in vitro and in vivo methods. An adeno-associated virus was used to overexpress AQP4 and TGN-020 was used to inhibit its function. This research revealed that the glymphatic system was impaired in PND mice and the blunted glymphatic transport was closely associated with the accumulation of inflammatory proteins in the hippocampus. Increasing AQP4 polarization could enhance glymphatic transport and suppresses neuroinflammation, thereby improve cognitive function in the PND model mice. However, a marked impaired glymphatic inflammatory proteins clearance and the more severe cognitive dysfunction were observed when decreasing AQP4 polarization. Therefore, long-term isoflurane anesthesia causes blunted glymphatic system by inducing AQP4 depolarization, enhanced the AQP4 polarization can alleviate the glymphatic system malfunction and reduce the neuroinflammatory response, which may be a potential treatment strategy for PND.
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Affiliation(s)
- Rui Dong
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
- Department of Anesthesiology, Qingdao Hospital, University of Health and Rehabilitation Sciences (Qingdao Municipal Hospital), Qingdao, China
| | - Yuqiang Han
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Pin Lv
- Department of Radiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Linhao Jiang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Zimo Wang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Liangyu Peng
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Shuai Liu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Zhengliang Ma
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Tianjiao Xia
- Medical School, Nanjing University, Nanjing, China
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing, China
| | - Bing Zhang
- Department of Radiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
- Medical School, Nanjing University, Nanjing, China
- Institute of Medical Imaging and Artificial Intelligence, Nanjing University, Nanjing, China
- Institute of Brain Science, Nanjing University, Nanjing, China
| | - Xiaoping Gu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
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7
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Jiang-Xie LF, Drieu A, Bhasiin K, Quintero D, Smirnov I, Kipnis J. Neuronal dynamics direct cerebrospinal fluid perfusion and brain clearance. Nature 2024; 627:157-164. [PMID: 38418877 DOI: 10.1038/s41586-024-07108-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 01/23/2024] [Indexed: 03/02/2024]
Abstract
The accumulation of metabolic waste is a leading cause of numerous neurological disorders, yet we still have only limited knowledge of how the brain performs self-cleansing. Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain. These waves are a plausible mechanism to explain the correlated potentiation of the glymphatic flow1,2 through the brain parenchyma. Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma. Notably, synthesized waves generated through transcranial optogenetic stimulation substantially potentiated cerebrospinal fluid-to-interstitial fluid perfusion. Our study demonstrates that neurons serve as master organizers for brain clearance. This fundamental principle introduces a new theoretical framework for the functioning of macroscopic brain waves.
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Affiliation(s)
- Li-Feng Jiang-Xie
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA.
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA.
| | - Antoine Drieu
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Kesshni Bhasiin
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Daniel Quintero
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Igor Smirnov
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA
| | - Jonathan Kipnis
- Brain Immunology and Glia (BIG) Center, Washington University in St Louis, St Louis, MO, USA.
- Department of Pathology and Immunology, School of Medicine, Washington University in St Louis, St Louis, MO, USA.
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8
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Hablitz L, Nedergaard M. Synchronized neuronal activity drives waste fluid flow. Nature 2024; 627:44-45. [PMID: 38418726 DOI: 10.1038/d41586-024-00422-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
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9
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Barbosa IDO, Pontes-Silva A, Prati JM. Dysfunction of the glymphatic system and sleep disturbance in rheumatoid arthritis and musculoskeletal pain: A gap related to pain becoming chronic. Autoimmun Rev 2024; 23:103500. [PMID: 38061620 DOI: 10.1016/j.autrev.2023.103500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 11/30/2023] [Indexed: 04/30/2024]
Affiliation(s)
| | - André Pontes-Silva
- Department of Physical Therapy, Federal University of São Carlos, São Carlos, SP, Brazil.
| | - José Mário Prati
- Department of Physical Therapy, Federal University of São Carlos, São Carlos, SP, Brazil
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10
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Chen X, Benveniste H, Tannenbaum AR. Unbalanced regularized optimal mass transport with applications to fluid flows in the brain. Sci Rep 2024; 14:1111. [PMID: 38212659 PMCID: PMC10784574 DOI: 10.1038/s41598-023-50874-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/27/2023] [Indexed: 01/13/2024] Open
Abstract
As a generalization of the optimal mass transport (OMT) approach of Benamou and Brenier's, the regularized optimal mass transport (rOMT) formulates a transport problem from an initial mass configuration to another with the optimality defined by the total kinetic energy, but subject to an advection-diffusion constraint equation. Both rOMT and the Benamou and Brenier's formulation require the total initial and final masses to be equal; mass is preserved during the entire transport process. However, for many applications, e.g., in dynamic image tracking, this constraint is rarely if ever satisfied. Therefore, we propose to employ an unbalanced version of rOMT to remove this constraint together with a detailed numerical solution procedure and applications to analyzing fluid flows in the brain.
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Affiliation(s)
- Xinan Chen
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, 10065, USA.
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, 06510, USA
| | - Allen R Tannenbaum
- Departments of Computer Science and Applied Mathematics & Statistics, Stony Brook University, Stony Brook, 11794, USA
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11
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Meng JC, Shen MQ, Lu YL, Feng HX, Chen XY, Xu DQ, Wu GH, Cheng QZ, Wang LH, Gui Q. Correlation of glymphatic system abnormalities with Parkinson's disease progression: a clinical study based on non-invasive fMRI. J Neurol 2024; 271:457-471. [PMID: 37755462 DOI: 10.1007/s00415-023-12004-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND The glymphatic system is reportedly involved in Parkinson's disease (PD). Based on previous studies, we aimed to confirm the correlation between the glymphatic system and PD progression by combining two imaging parameters, diffusion tensor image analysis along the perivascular space (DTI-ALPS), and enlarged perivascular spaces (EPVS). METHODS Fifty-one PD patients and fifty healthy control (HC) were included. Based on the Hoehn-Yahr scale, the PD group was divided into early-stage and medium-to late-stage. All PD patients were scored using the Unified PD Rating Scale (UPDRS). We assessed the DTI-ALPS indices in the bilateral hemispheres and EPVS numbers in bilateral centrum semiovale (CSO), basal ganglia (BG), and midbrain. RESULTS The DTI-ALPS indices were significantly lower bilaterally in PD patients than in the HC group, and EPVS numbers in any of the bilateral CSO, BG, and midbrain were significantly higher, especially for the medium- to late-stage group and the BG region. In PD patients, the DTI-ALPS index was significantly negatively correlated with age, while the BG-EPVS numbers were significantly positively correlated with age. Furthermore, the DTI-ALPS index was negatively correlated with UPDRS II and III scores, while the BG-EPVS numbers were positively correlated with UPDRS II and III scores. Similarly, the correlation was more pronounced in the medium- to late-stage group. CONCLUSION The DTI-ALPS index and EPVS numbers (especially in the BG region) are closely related to age and PD progression and can serve as non-invasive assessments for glymphatic dysfunction and its interventions in clinical studies.
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Affiliation(s)
- Jing-Cai Meng
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, 215123, Jiangsu, China
| | - Ming-Qiang Shen
- Department of Neurology, Suzhou Hospital Affiliated to Nanjing Medical University (Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China
| | - Yan-Li Lu
- Department of Radiology, Suzhou Hospital Affiliated to Nanjing Medical University(Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China
| | - Hong-Xuan Feng
- Department of Neurology, Suzhou Hospital Affiliated to Nanjing Medical University (Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China
| | - Xin-Yi Chen
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, 215123, Jiangsu, China
| | - Da-Qiang Xu
- Department of Radiology, Suzhou Hospital Affiliated to Nanjing Medical University(Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China
| | - Guan-Hui Wu
- Department of Neurology, Suzhou Hospital Affiliated to Nanjing Medical University (Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China
| | - Qing-Zhang Cheng
- Department of Neurology, Suzhou Hospital Affiliated to Nanjing Medical University (Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China
| | - Lin-Hui Wang
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, 215123, Jiangsu, China
| | - Qian Gui
- Department of Neurology, Suzhou Hospital Affiliated to Nanjing Medical University (Suzhou Municipal Hospital), Suzhou, 215002, Jiangsu, China.
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12
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Eisen A, Vucic S, Mitsumoto H. History of ALS and the competing theories on pathogenesis: IFCN handbook chapter. Clin Neurophysiol Pract 2023; 9:1-12. [PMID: 38213309 PMCID: PMC10776891 DOI: 10.1016/j.cnp.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/07/2023] [Accepted: 11/28/2023] [Indexed: 01/13/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the human motor system, first described in the 19th Century. The etiology of ALS appears to be multifactorial, with a complex interaction of genetic, epigenetic, and environmental factors underlying the onset of disease. Importantly, there are no known naturally occurring animal models, and transgenic mouse models fail to faithfully reproduce ALS as it manifests in patients. Debate as to the site of onset of ALS remain, with three competing theories proposed, including (i) the dying-forward hypothesis, whereby motor neuron degeneration is mediated by hyperexcitable corticomotoneurons via an anterograde transsynaptic excitotoxic mechanism, (ii) dying-back hypothesis, proposing the ALS begins in the peripheral nervous system with a toxic factor(s) retrogradely transported into the central nervous system and mediating upper motor neuron dysfunction, and (iii) independent hypothesis, suggesting that upper and lower motor neuron degenerated independently. Transcranial magnetic stimulation studies, along with pathological and genetic findings have supported the dying forward hypothesis theory, although the science is yet to be settled. The review provides a historical overview of ALS, discusses phenotypes and likely pathogenic mechanisms.
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Affiliation(s)
- Andrew Eisen
- Division of Neurology, Department of Medicine, University of British Columbia, Canada
| | - Steve Vucic
- Director Brain and Nerve Research Center, Clinical School, University of Sydney, Australia
| | - Hiroshi Mitsumoto
- Wesley J. Howe Professor of Neurology, Columbia University, The Neurological Institute of New York, and New York-Presbyterian Hospital/Columbia University Medical Center, United States
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13
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Helakari H, Järvelä M, Väyrynen T, Tuunanen J, Piispala J, Kallio M, Ebrahimi SM, Poltojainen V, Kananen J, Elabasy A, Huotari N, Raitamaa L, Tuovinen T, Korhonen V, Nedergaard M, Kiviniemi V. Effect of sleep deprivation and NREM sleep stage on physiological brain pulsations. Front Neurosci 2023; 17:1275184. [PMID: 38105924 PMCID: PMC10722275 DOI: 10.3389/fnins.2023.1275184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/02/2023] [Indexed: 12/19/2023] Open
Abstract
Introduction Sleep increases brain fluid transport and the power of pulsations driving the fluids. We investigated how sleep deprivation or electrophysiologically different stages of non-rapid-eye-movement (NREM) sleep affect the human brain pulsations. Methods Fast functional magnetic resonance imaging (fMRI) was performed in healthy subjects (n = 23) with synchronous electroencephalography (EEG), that was used to verify arousal states (awake, N1 and N2 sleep). Cardiorespiratory rates were verified with physiological monitoring. Spectral power analysis assessed the strength, and spectral entropy assessed the stability of the pulsations. Results In N1 sleep, the power of vasomotor (VLF < 0.1 Hz), but not cardiorespiratory pulsations, intensified after sleep deprived vs. non-sleep deprived subjects. The power of all three pulsations increased as a function of arousal state (N2 > N1 > awake) encompassing brain tissue in both sleep stages, but extra-axial CSF spaces only in N2 sleep. Spectral entropy of full band and respiratory pulsations decreased most in N2 sleep stage, while cardiac spectral entropy increased in ventricles. Discussion In summary, the sleep deprivation and sleep depth, both increase the power and harmonize the spectral content of human brain pulsations.
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Affiliation(s)
- Heta Helakari
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Matti Järvelä
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Tommi Väyrynen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Johanna Tuunanen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Johanna Piispala
- Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Mika Kallio
- Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Seyed Mohsen Ebrahimi
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Valter Poltojainen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Janne Kananen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
- Clinical Neurophysiology, Oulu University Hospital, Oulu, Finland
| | - Ahmed Elabasy
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Niko Huotari
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Lauri Raitamaa
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Timo Tuovinen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Vesa Korhonen
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Maiken Nedergaard
- Center of Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
- Center of Translational Neuromedicine, University of Rochester, Rochester, NY, United States
| | - Vesa Kiviniemi
- Oulu Functional Neuroimaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
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Lv C, Han S, Sha Z, Liu M, Dong S, Zhang C, Li Z, Zhang K, Lu S, Xu Z, Bie L, Jiang R. Cerebral glucagon-like peptide-1 receptor activation alleviates traumatic brain injury by glymphatic system regulation in mice. CNS Neurosci Ther 2023; 29:3876-3888. [PMID: 37353947 PMCID: PMC10651945 DOI: 10.1111/cns.14308] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/21/2023] [Accepted: 05/30/2023] [Indexed: 06/25/2023] Open
Abstract
AIM We aimed to assess the effects of cerebral glucagon-like peptide-1 receptor (GLP-1R) activation on the glymphatic system and whether this effect was therapeutic for traumatic brain injury (TBI). METHODS Immunofluorescence was employed to evaluate glymphatic system function. The blood-brain barrier (BBB) permeability, microvascular basement membrane, and tight junction expression were assessed using Evans blue extravasation, immunofluorescence, and western blot. Immunohistochemistry was performed to assess axonal damage. Neuronal apoptosis was evaluated using Nissl staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and western blot. Cognitive function was assessed using behavioral tests. RESULTS Cerebral GLP-1R activation restored glymphatic transport following TBI, alleviating BBB disruption and neuronal apoptosis, thereby improving cognitive function following TBI. Glymphatic function suppression by treatment using aquaporin 4 inhibitor TGN-020 abolished the protective effect of the GLP-1R agonist against cognitive impairment. CONCLUSION Cerebral GLP-1R activation can effectively ameliorate neuropathological changes and cognitive impairment following TBI; the underlying mechanism could involve the repair of the glymphatic system damaged by TBI.
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Affiliation(s)
- Chuanxiang Lv
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Shuai Han
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Zhuang Sha
- Department of NeurosurgeryTianjin Medical University General HospitalTianjinChina
- Tianjin Neurological Institute, Key Laboratory of Post‐Neuroinjury Neuro‐repair and Regeneration in Central Nervous SystemTianjin Medical University General Hospital, Ministry of EducationTianjinChina
| | - Mingqi Liu
- Department of NeurosurgeryTianjin Medical University General HospitalTianjinChina
- Tianjin Neurological Institute, Key Laboratory of Post‐Neuroinjury Neuro‐repair and Regeneration in Central Nervous SystemTianjin Medical University General Hospital, Ministry of EducationTianjinChina
| | - Shiying Dong
- Department of NeurosurgeryTianjin Medical University General HospitalTianjinChina
- Tianjin Neurological Institute, Key Laboratory of Post‐Neuroinjury Neuro‐repair and Regeneration in Central Nervous SystemTianjin Medical University General Hospital, Ministry of EducationTianjinChina
| | - Chunyun Zhang
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Zean Li
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Kang Zhang
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Shouyong Lu
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Zhiyang Xu
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Li Bie
- Department of NeurosurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Rongcai Jiang
- Department of NeurosurgeryTianjin Medical University General HospitalTianjinChina
- Tianjin Neurological Institute, Key Laboratory of Post‐Neuroinjury Neuro‐repair and Regeneration in Central Nervous SystemTianjin Medical University General Hospital, Ministry of EducationTianjinChina
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Tang M, Wu L, Shen Z, Chen J, Yang Y, Zhang M, Zhao P, Jiang G. Association between Sleep and Alzheimer's Disease: A Bibliometric Analysis from 2003 to 2022. Neuroepidemiology 2023; 57:377-390. [PMID: 37699365 DOI: 10.1159/000533700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/26/2023] [Indexed: 09/14/2023] Open
Abstract
INTRODUCTION Alzheimer's disease (AD) often presents with sleep disorders, which are also an important risk factor for AD, affecting cognitive function to a certain extent. This study aimed to reveal the current global status, present hotspots, and discuss emerging trends of sleep and AD using a bibliometric approach. METHODS Research and review articles related to sleep and AD from 2003 to 2022 were extracted from the Web of Science Core Collection. VOSviewer 1.6.18.0, Scimago Graphica, and CiteSpace 6.2.R2 were used to map the productive and highly cited countries, institutions, journals, authors, references, and keywords in the field. RESULTS Overall, 4,008 publications were included in this bibliometric analysis. The number of publications and citations showed an increasing trend over the past two decades. The USA and China had the largest and second largest, respectively, number of publications and citations and cooperated with other countries more closely. Ancoli-Israel Sonia published the most papers, and Holtzman David M was co-cited most frequently. The most productive journal was Journal of Alzheimer's Disease, and Neurology was the most frequently cited journal. The risk factors, β-amyloid (Aβ), tau, neuroinflammation, astrocytes, glymphatic system, orexin, functional connectivity, and management have been the main research directions of researchers over the past few years and may be the future trend of valuable research. CONCLUSION We identified hotspots and emerging trends including risk factors, Aβ, tau, neuroinflammation, the glymphatic system, orexin, and management, which may help identify new therapeutic targets and improve clinical efficacy of sleep and AD.
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Affiliation(s)
- Ming Tang
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Li Wu
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Ziyi Shen
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Junwen Chen
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Yang Yang
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Ming Zhang
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Peilin Zhao
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
| | - Guohui Jiang
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College; Institute of Neurological Diseases, North Sichuan Medical College, Nanchong, China
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Kim D, Gan Y, Nedergaard M, Kelley DH, Tithof J. Image Analysis Techniques for In Vivo Quantification of Cerebrospinal Fluid Flow. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.20.549937. [PMID: 37546970 PMCID: PMC10401935 DOI: 10.1101/2023.07.20.549937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Over the last decade, there has been a tremendously increased interest in understanding the neurophysiology of cerebrospinal fluid (CSF) flow, which plays a crucial role in clearing metabolic waste from the brain. This growing interest was largely initiated by two significant discoveries: the glymphatic system (a pathway for solute exchange between interstitial fluid deep within the brain and the CSF surrounding the brain) and meningeal lymphatic vessels (lymphatic vessels in the layer of tissue surrounding the brain that drain CSF). These two CSF systems work in unison, and their disruption has been implicated in several neurological disorders including Alzheimer's disease, stoke, and traumatic brain injury. Here, we present experimental techniques for in vivo quantification of CSF flow via direct imaging of fluorescent microspheres injected into the CSF. We discuss detailed image processing methods, including registration and masking of stagnant particles, to improve the quality of measurements. We provide guidance for quantifying CSF flow through particle tracking and offer tips for optimizing the process. Additionally, we describe techniques for measuring changes in arterial diameter, which is an hypothesized CSF pumping mechanism. Finally, we outline how these same techniques can be applied to cervical lymphatic vessels, which collect fluid downstream from meningeal lymphatic vessels. We anticipate that these fluid mechanical techniques will prove valuable for future quantitative studies aimed at understanding mechanisms of CSF transport and disruption, as well as for other complex biophysical systems.
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Affiliation(s)
- Daehyun Kim
- Department of Mechanical Engineering, University of Minnesota, 111 Church St SE, Minneapolis, MN, 55455, United States
| | - Yiming Gan
- Department of Mechanical Engineering, University of Rochester, Hopeman Engineering Bldg, Rochester, NY, 14627, United States
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, 14642, United States
| | - Douglas H. Kelley
- Department of Mechanical Engineering, University of Rochester, Hopeman Engineering Bldg, Rochester, NY, 14627, United States
| | - Jeffrey Tithof
- Department of Mechanical Engineering, University of Minnesota, 111 Church St SE, Minneapolis, MN, 55455, United States
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Rollo J, Crawford J, Hardy J. A dynamical systems approach for multiscale synthesis of Alzheimer's pathogenesis. Neuron 2023; 111:2126-2139. [PMID: 37172582 DOI: 10.1016/j.neuron.2023.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 12/15/2022] [Accepted: 04/13/2023] [Indexed: 05/15/2023]
Abstract
Alzheimer's disease (AD) is a spatially dynamic pathology that implicates a growing volume of multiscale data spanning genetic, cellular, tissue, and organ levels of the organization. These data and bioinformatics analyses provide clear evidence for the interactions within and between these levels. The resulting heterarchy precludes a linear neuron-centric approach and necessitates that the numerous interactions are measured in a way that predicts their impact on the emergent dynamics of the disease. This level of complexity confounds intuition, and we propose a new methodology that uses non-linear dynamical systems modeling to augment intuition and that links with a community-wide participatory platform to co-create and test system-level hypotheses and interventions. In addition to enabling the integration of multiscale knowledge, key benefits include a more rapid innovation cycle and a rational process for prioritization of data campaigns. We argue that such an approach is essential to support the discovery of multilevel-coordinated polypharmaceutical interventions.
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Affiliation(s)
- Jennifer Rollo
- Department of Neurodegenerative Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK.
| | - John Crawford
- Adam Smith Business School, University of Glasgow, Glasgow G12 8QQ, UK
| | - John Hardy
- Department of Neurodegenerative Diseases, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
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18
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Raicevic N, Forer JM, Ladrón-de-Guevara A, Du T, Nedergaard M, Kelley DH, Boster K. Sizes and shapes of perivascular spaces surrounding murine pial arteries. Fluids Barriers CNS 2023; 20:56. [PMID: 37461047 PMCID: PMC10351203 DOI: 10.1186/s12987-023-00454-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/21/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Flow of cerebrospinal fluid (CSF) through brain perivascular spaces (PVSs) is essential for the clearance of interstitial metabolic waste products whose accumulation and aggregation is a key mechanism of pathogenesis in many diseases. The PVS geometry has important implications for CSF flow as it affects CSF and solute transport rates. Thus, the size and shape of the perivascular spaces are essential parameters for models of CSF transport in the brain and require accurate quantification. METHODS We segmented two-photon images of pial (surface) PVSs and the adjacent arteries and characterized their sizes and shapes of cross sections from 14 PVS segments in 9 mice. Based on the analysis, we propose an idealized model that approximates the cross-sectional size and shape of pial PVSs, closely matching their area ratios and hydraulic resistances. RESULTS The ratio of PVS-to-vessel area varies widely across the cross sections analyzed. The hydraulic resistance per unit length of the PVS scales with the PVS cross-sectional area, and we found a power-law fit that predicts resistance as a function of the area. Three idealized geometric models were compared to PVSs imaged in vivo, and their accuracy in reproducing hydraulic resistances and PVS-to-vessel area ratios were evaluated. The area ratio was obtained across different cross sections, and we found that the distribution peaks for the original PVS and its closest idealized fit (polynomial fit) were 1.12 and 1.21, respectively. The peak of the hydraulic resistance distribution is [Formula: see text] Pa s/m[Formula: see text] and [Formula: see text] Pa s/m[Formula: see text] for the segmentation and its closest idealized fit, respectively. CONCLUSIONS PVS hydraulic resistance can be reasonably predicted as a function of the PVS area. The proposed polynomial-based fit most closely captures the shape of the PVS with respect to area ratio and hydraulic resistance. Idealized PVS shapes are convenient for modeling, which can be used to better understand how anatomical variations affect clearance and drug transport.
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Affiliation(s)
- Nikola Raicevic
- Department of Mechanical Engineering, University of Rochester, Rochester, USA
| | - Jarod M Forer
- Department of Mechanical Engineering, University of Rochester, Rochester, USA
| | - Antonio Ladrón-de-Guevara
- Center for Translational Neuromedicine and Department of Neuroscience, University of Rochester Medical Center, Rochester, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, USA
| | - Ting Du
- Center for Translational Neuromedicine and Department of Neuroscience, University of Rochester Medical Center, Rochester, USA
- School of Pharmacy, China Medical University, Shenyang, Liaoning, China
| | - Maiken Nedergaard
- Center for Translational Neuromedicine and Department of Neuroscience, University of Rochester Medical Center, Rochester, USA
| | - Douglas H Kelley
- Department of Mechanical Engineering, University of Rochester, Rochester, USA
| | - Kimberly Boster
- Department of Mechanical Engineering, University of Rochester, Rochester, USA.
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Mohamed W, Kumar J, Alghamdi BS, Soliman AH, Toshihide Y. Neurodegeneration and inflammation crosstalk: Therapeutic targets and perspectives. IBRO Neurosci Rep 2023; 14:95-110. [PMID: 37388502 PMCID: PMC10300452 DOI: 10.1016/j.ibneur.2022.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/19/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Glia, which was formerly considered to exist just to connect neurons, now plays a key function in a wide range of physiological events, including formation of memory, learning, neuroplasticity, synaptic plasticity, energy consumption, and homeostasis of ions. Glial cells regulate the brain's immune responses and confers nutritional and structural aid to neurons, making them an important player in a broad range of neurological disorders. Alzheimer's, ALS, Parkinson's, frontotemporal dementia (FTD), and epilepsy are a few of the neurodegenerative diseases that have been linked to microglia and astroglia cells, in particular. Synapse growth is aided by glial cell activity, and this activity has an effect on neuronal signalling. Each glial malfunction in diverse neurodegenerative diseases is distinct, and we will discuss its significance in the progression of the illness, as well as its potential for future treatment.
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Affiliation(s)
- Wael Mohamed
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia
- Clinical Pharmacology Department, Menoufia Medical School, Menoufia University, Menoufia, Egypt
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, UKM Medical Centre (UKMMC), Kuala Lumpur, Malaysia
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Khan M, Clijsters M, Choi S, Backaert W, Claerhout M, Couvreur F, Van Breda L, Bourgeois F, Speleman K, Klein S, Van Laethem J, Verstappen G, Dereli AS, Yoo SJ, Zhou H, Dan Do TN, Jochmans D, Laenen L, Debaveye Y, De Munter P, Gunst J, Jorissen M, Lagrou K, Meersseman P, Neyts J, Thal DR, Topsakal V, Vandenbriele C, Wauters J, Mombaerts P, Van Gerven L. Anatomical barriers against SARS-CoV-2 neuroinvasion at vulnerable interfaces visualized in deceased COVID-19 patients. Neuron 2022; 110:3919-3935.e6. [PMID: 36446381 PMCID: PMC9647025 DOI: 10.1016/j.neuron.2022.11.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/26/2022] [Accepted: 11/08/2022] [Indexed: 11/11/2022]
Abstract
Can SARS-CoV-2 hitchhike on the olfactory projection and take a direct and short route from the nose into the brain? We reasoned that the neurotropic or neuroinvasive capacity of the virus, if it exists, should be most easily detectable in individuals who died in an acute phase of the infection. Here, we applied a postmortem bedside surgical procedure for the rapid procurement of tissue, blood, and cerebrospinal fluid samples from deceased COVID-19 patients infected with the Delta, Omicron BA.1, or Omicron BA.2 variants. Confocal imaging of sections stained with fluorescence RNAscope and immunohistochemistry afforded the light-microscopic visualization of extracellular SARS-CoV-2 virions in tissues. We failed to find evidence for viral invasion of the parenchyma of the olfactory bulb and the frontal lobe of the brain. Instead, we identified anatomical barriers at vulnerable interfaces, exemplified by perineurial olfactory nerve fibroblasts enwrapping olfactory axon fascicles in the lamina propria of the olfactory mucosa.
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Affiliation(s)
- Mona Khan
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | - Marnick Clijsters
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research, KU Leuven, Leuven, Belgium
| | - Sumin Choi
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | - Wout Backaert
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Group, KU Leuven, Leuven, Belgium
| | - Michiel Claerhout
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Floor Couvreur
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Laure Van Breda
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Florence Bourgeois
- Department of Otorhinolaryngology, Head and Neck Surgery, AZ Sint-Jan Brugge-Oostende AV, Bruges, Belgium
| | - Kato Speleman
- Department of Otorhinolaryngology, Head and Neck Surgery, AZ Sint-Jan Brugge-Oostende AV, Bruges, Belgium
| | - Sam Klein
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Johan Van Laethem
- Department of Infectious Diseases, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Gill Verstappen
- Department of Otorhinolaryngology - Head and Neck Surgery, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Seung-Jun Yoo
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany; Department of Life Science, College of Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Hai Zhou
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany
| | - Thuc Nguyen Dan Do
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, KU Leuven, Leuven, Belgium
| | - Dirk Jochmans
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, KU Leuven, Leuven, Belgium
| | - Lies Laenen
- Department of Laboratory Medicine & National Reference Center for Respiratory Pathogens, University Hospitals Leuven, Leuven, Belgium
| | - Yves Debaveye
- Intensive Care Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cellular and Molecular Medicine, Laboratory of Intensive Care Medicine, KU Leuven, Leuven, Belgium
| | - Paul De Munter
- Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, KU Leuven, Leuven, Belgium
| | - Jan Gunst
- Intensive Care Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cellular and Molecular Medicine, Laboratory of Intensive Care Medicine, KU Leuven, Leuven, Belgium
| | - Mark Jorissen
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research, KU Leuven, Leuven, Belgium; Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Katrien Lagrou
- Department of Laboratory Medicine & National Reference Center for Respiratory Pathogens, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical Bacteriology and Mycology, KU Leuven, Leuven, Belgium
| | - Philippe Meersseman
- Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, KU Leuven, Leuven, Belgium
| | - Johan Neyts
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, KU Leuven, Leuven, Belgium
| | - Dietmar Rudolf Thal
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium; Laboratory of Neuropathology, Department of Imaging & Pathology and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Vedat Topsakal
- Department of Otorhinolaryngology - Head and Neck Surgery, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Christophe Vandenbriele
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Joost Wauters
- Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Laboratory for Clinical Infectious and Inflammatory Disorders, KU Leuven, Leuven, Belgium
| | - Peter Mombaerts
- Max Planck Research Unit for Neurogenetics, Frankfurt, Germany.
| | - Laura Van Gerven
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research, KU Leuven, Leuven, Belgium; Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Group, KU Leuven, Leuven, Belgium.
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Cong Y, Baimanov D, Zhou Y, Chen C, Wang L. Penetration and translocation of functional inorganic nanomaterials into biological barriers. Adv Drug Deliv Rev 2022; 191:114615. [PMID: 36356929 DOI: 10.1016/j.addr.2022.114615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/23/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
With excellent physicochemical properties, inorganic nanomaterials (INMs) have exhibited a series of attractive applications in biomedical fields. Biological barriers prevent successful delivery of nanomedicine in living systems that limits the development of nanomedicine especially for sufficient delivery of drugs and effective therapy. Numerous researches have focused on overcoming these biological barriers and homogeneity of organisms to enhance therapeutic efficacy, however, most of these strategies fail to resolve these challenges. In this review, we present the latest progress about how INMs interact with biological barriers and penetrate these barriers. We also summarize that both native structure and components of biological barriers and physicochemical properties of INMs contributed to the penetration capacity. Knowledge about the relationship between INMs structure and penetration capacity will guide the design and application of functional and efficient nanomedicine in the future.
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Affiliation(s)
- Yalin Cong
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China & Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China
| | - Didar Baimanov
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China & Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China; Engineering Research Center of Clinical Functional Materials and Diagnosis & Treatment Devices of Zhejiang Province, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, PR China
| | - Yunlong Zhou
- Engineering Research Center of Clinical Functional Materials and Diagnosis & Treatment Devices of Zhejiang Province, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, PR China
| | - Chunying Chen
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China & Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; GBA Research Innovation Institute for Nanotechnology, Guangzhou 510700, Guangdong, PR China; Research Unit of Nanoscience and Technology, Chinese Academy of Medical Sciences, Beijing 100730, PR China
| | - Liming Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China & Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; CAS-HKU Joint Laboratory of Metallomics on Health and Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China.
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22
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Reynolds WF, Malle E, Maki RA. Thiocyanate Reduces Motor Impairment in the hMPO-A53T PD Mouse Model While Reducing MPO-Oxidation of Alpha Synuclein in Enlarged LYVE1/AQP4 Positive Periventricular Glymphatic Vessels. Antioxidants (Basel) 2022; 11:antiox11122342. [PMID: 36552550 PMCID: PMC9774557 DOI: 10.3390/antiox11122342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Parkinson's disease (PD) is due to the oxidation of alpha synuclein (αSyn) contributing to motor impairment. We developed a transgenic mouse model of PD that overexpresses the mutated human αSyn gene (A53T) crossed to a mouse expressing the human MPO gene. This model exhibits increased oxidation and chlorination of αSyn leading to greater motor impairment. In the current study, the hMPO-A53T mice were treated with thiocyanate (SCN-) which is a favored substrate of MPO as compared to chlorine. We show that hMPO-A53T mice treated with SCN- have less chlorination in the brain and show an improvement in motor skills compared to the nontreated hMPO-A53T mice. Interestingly, in the hMPO-A53T mice we found a possible link between MPO-related disease and the glymphatic system which clears waste including αSyn from the brain. The untreated hMPO-A53T mice exhibited an increase in the size of periventricular glymphatic vessels expressing the glymphatic marker LYVE1 and aquaporin 4 (AQP4). These vessels also exhibited an increase in MPO and HOCl-modified epitopes in the glymphatic vessels correlating with loss of ependymal cells lining the ventricles. These findings suggest that MPO may significantly promote the impairment of the glymphatic waste removal system thus contributing to neurodegeneration in PD. Moreover, the inhibition of MPO chlorination/oxidation by SCN- may provide a potential therapeutic approach to this disease.
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Affiliation(s)
- Wanda F. Reynolds
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- Correspondence:
| | - Ernst Malle
- Gottfried Schatz Research Center, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Richard A. Maki
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
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23
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Kumaria A. Terson syndrome as a marker of severity in acute brain injuries: More than meets the eye. Neurologia 2022; 37:827-828. [PMID: 36468433 DOI: 10.1016/j.nrleng.2022.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 06/09/2022] [Indexed: 01/31/2023] Open
Affiliation(s)
- A Kumaria
- Department of Neurosurgery, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK.
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24
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The putative role of trigemino-vascular system in brain perfusion homeostasis and the significance of the migraine attack. Neurol Sci 2022; 43:5665-5672. [PMID: 35802218 PMCID: PMC9385793 DOI: 10.1007/s10072-022-06200-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/01/2022] [Indexed: 11/23/2022]
Abstract
Besides representing the place where a migraine attack generates, what is the physiological role of peptidergic control of arteriolar caliber within the trigemino-vascular system? Considering that the shared goal of most human CGRP-based neurosensory systems is the protection from an acute threat, especially if hypoxic, what is the end meaning of a migraine attack? In this paper, we have reviewed available evidence on the possible role of the trigemino-vascular system in maintaining cerebral perfusion pressure homeostasis, despite the large physiological fluctuations in intracranial pressure occurring in daily life activities. In this perspective, the migraine attack is presented as the response to a cerebral hypoxic threat consequent to a deranged intracranial pressure control aimed at generating a temporary withdrawal from the environment with limitation of physical activity, a condition required to promote the restoration of cerebral fluids dynamic balance.
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25
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Terson syndrome as a marker of severity in acute brain injuries: More than meets the eye. Neurologia 2022. [DOI: 10.1016/j.nrl.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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26
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Role of Tissue Hydraulic Permeability in Convection-Enhanced Delivery of Nanoparticle-Encapsulated Chemotherapy Drugs to Brain Tumour. Pharm Res 2022; 39:877-892. [PMID: 35474156 PMCID: PMC9160122 DOI: 10.1007/s11095-022-03261-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/07/2022] [Indexed: 12/12/2022]
Abstract
PURPOSE Tissue hydraulic permeability of brain tumours can vary considerably depending on the tissue microstructure, compositions in interstitium and tumour cells. Its effects on drug transport and accumulation remain poorly understood. METHODS Mathematical modelling is applied to predict the drug delivery outcomes in tumours with different tissue permeability upon convection-enhanced delivery. The modelling is based on a 3-D realistic tumour model that is extracted from patient magnetic resonance images. RESULTS Modelling results show that infusing drugs into a permeable tumour can facilitate a more favourable hydraulic environment for drug transport. The infused drugs will exhibit a relatively uniform distribution and cover a larger tumour volume for effective cell killing. Cross-comparisons show the delivery outcomes are more sensitive to the changes in tissue hydraulic permeability and blood pressure than the fluid flow from the brain ventricle. Quantitative analyses demonstrate that increasing the fluid gain from both the blood and brain ventricle can further improve the interstitial fluid flow, and thereby enhance the delivery outcomes. Furthermore, similar responses to the changes in tissue hydraulic permeability can be found for different types of drugs. CONCLUSIONS Tissue hydraulic permeability as an intrinsic property can influence drug accumulation and distribution. Results from this study can deepen the understanding of the interplays between drug and tissues that are involved in the drug delivery processes in chemotherapy.
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27
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Lopes DM, Llewellyn SK, Harrison IF. Propagation of tau and α-synuclein in the brain: therapeutic potential of the glymphatic system. Transl Neurodegener 2022; 11:19. [PMID: 35314000 PMCID: PMC8935752 DOI: 10.1186/s40035-022-00293-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/03/2022] [Indexed: 12/12/2022] Open
Abstract
Many neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease, are characterised by the accumulation of misfolded protein deposits in the brain, leading to a progressive destabilisation of the neuronal network and neuronal death. Among the proteins that can abnormally accumulate are tau and α-synuclein, which can propagate in a prion-like manner and which upon aggregation, represent the most common intracellular proteinaceous lesions associated with neurodegeneration. For years it was thought that these intracellular proteins and their accumulation had no immediate relationship with extracellular homeostasis pathways such as the glymphatic clearance system; however, mounting evidence has now suggested that this is not the case. The involvement of the glymphatic system in neurodegenerative disease is yet to be fully defined; however, it is becoming increasingly clear that this pathway contributes to parenchymal solute clearance. Importantly, recent data show that proteins prone to intracellular accumulation are subject to glymphatic clearance, suggesting that this system plays a key role in many neurological disorders. In this review, we provide a background on the biology of tau and α-synuclein and discuss the latest findings on the cell-to-cell propagation mechanisms of these proteins. Importantly, we discuss recent data demonstrating that manipulation of the glymphatic system may have the potential to alleviate and reduce pathogenic accumulation of propagation-prone intracellular cytotoxic proteins. Furthermore, we will allude to the latest potential therapeutic opportunities targeting the glymphatic system that might have an impact as disease modifiers in neurodegenerative diseases.
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28
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Takahashi S. Metabolic Contribution and Cerebral Blood Flow Regulation by Astrocytes in the Neurovascular Unit. Cells 2022; 11:cells11050813. [PMID: 35269435 PMCID: PMC8909328 DOI: 10.3390/cells11050813] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 12/10/2022] Open
Abstract
The neurovascular unit (NVU) is a conceptual framework that has been proposed to better explain the relationships between the neural cells and blood vessels in the human brain, focused mainly on the brain gray matter. The major components of the NVU are the neurons, astrocytes (astroglia), microvessels, pericytes, and microglia. In addition, we believe that oligodendrocytes should also be included as an indispensable component of the NVU in the white matter. Of all these components, astrocytes in particular have attracted the interest of researchers because of their unique anatomical location; these cells are interposed between the neurons and the microvessels of the brain. Their location suggests that astrocytes might regulate the cerebral blood flow (CBF) in response to neuronal activity, so as to ensure an adequate supply of glucose and oxygen to meet the metabolic demands of the neurons. In fact, the adult human brain, which accounts for only 2% of the entire body weight, consumes approximately 20–25% of the total amount of glucose and oxygen consumed by the whole body. The brain needs a continuous supply of these essential energy sources through the CBF, because there are practically no stores of glucose or oxygen in the brain; both acute and chronic cessation of CBF can adversely affect brain functions. In addition, another important putative function of the NVU is the elimination of heat and waste materials produced by neuronal activity. Recent evidence suggests that astrocytes play pivotal roles not only in supplying glucose, but also fatty acids and amino acids to neurons. Loss of astrocytic support can be expected to lead to malfunction of the NVU as a whole, which underlies numerous neurological disorders. In this review, we shall focus on historical and recent findings with regard to the metabolic contributions of astrocytes in the NVU.
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Affiliation(s)
- Shinichi Takahashi
- Department of Neurology and Stroke, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka-shi 350-1298, Japan; ; Tel.: +81-42-984-4111 (ext. 7412) or +81-3-3353-1211 (ext. 62613); Fax: +81-42-984-0664 or +81-3-3357-5445
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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29
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Carneiro-Nascimento S, Levy D. Cortical spreading depression and meningeal nociception. NEUROBIOLOGY OF PAIN 2022; 11:100091. [PMID: 35518782 PMCID: PMC9065921 DOI: 10.1016/j.ynpai.2022.100091] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/11/2022] [Accepted: 04/14/2022] [Indexed: 01/07/2023]
Abstract
CSD evoked persistent activation and mechanical sensitization of dural nociceptors is likely to drive the headache phase in migraine with aura. The development of neurogenic-mediated dural vasodilatation and increased plasma protein extravasation in the wake of CSD may not contribute to meningeal nociception. Cortical vasoconstriction and reduced oxygen availability following CSD do not contribute to meningeal nociception. Cortical neuroinflammation, involving neuronal pannexin1 and calcium-independent astrocytic signaling drive meningeal nociception following CSD. CSD-related closing of K(ATP) channels and release of COX-driven prostanoids mediate the activation and sensitization of dural nociceptors respectively.
Migraine results in an enormous burden on individuals and societies due to its high prevalence, significant disability, and considerable economic costs. Current treatment options for migraine remain inadequate, and the development of novel therapies is severely hindered by the incomplete understanding of the mechanisms responsible for the pain. The sensory innervation of the cranial meninges is now considered a key player in migraine headache genesis. Recent studies have significantly advanced our understanding of some of the processes that drive meningeal nociceptive neurons, which may be targeted therapeutically to abort or prevent migraine pain. In this review we will summarize our current understanding of the mechanisms that contribute to the genesis of the headache in one migraine subtype – migraine with aura. We will focus on animal studies that address the notion that cortical spreading depression is a critical process that drives meningeal nociception in migraine with aura, and discuss recent insights into some of the proposed underlying mechanisms.
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