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Tan X, Li X, Li R, Meng W, Xie Z, Li J, Pang Y, Huang G, Li L, Li H. β-hydroxybutyrate alleviates neurological deficits by restoring glymphatic and inflammation after subarachnoid hemorrhage in mice. Exp Neurol 2024; 378:114819. [PMID: 38763355 DOI: 10.1016/j.expneurol.2024.114819] [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: 03/01/2024] [Revised: 05/07/2024] [Accepted: 05/16/2024] [Indexed: 05/21/2024]
Abstract
BACKGROUND Both glymphatic system dysfunction and inflammatory response aggravate neurological dysfunction after subarachnoid hemorrhage (SAH). Studies have shown that β-hydroxybutyrate (BHB) may mitigate painful diabetic neuropathy (PDN) by upregulating SNTA1 expression and reinstating AQP4 polarity. However, the potential of BHB to ameliorate glymphatic system function and inflammatory response in SAH mice remains uncertain. METHODS The SAH models were constructed by injection of arterial blood into cisterna Magana. Three groups of C57 mice were randomly assigned: Sham, SAH, and BHB. All mice were subjected to neurological function assessment, western blot, immunofluorescence double staining, and RNA-seq. Glymphatic system function was examined with tracer and immunofluorescence double staining, and the differential genes were examined with RNA-seq. In addition, the expression of related inflammation was detected. RESULTS Compared with the SAH group, BHB reinstated AQP4 polarization by upregulating SNTA1 protein to enhance the glymphatic system. According to RNA-seq, the different genes were primarily connected to microglia activation, astrocytes, and inflammation. Western blot and immunofluorescence further confirmed that the related inflammatory protein expression levels were upregulated. BHB attenuated neuroinflammation after SAH. Ultimately, it can mitigate the neurological deficits in SAH mice. CONCLUSION The study reveals a novel mechanism that BHB treatment mitigates neurologic impairment in SAH mice. We propose that BHB may play a neuroprotective effect by enhancing glymphatic system function and attenuating neuroinflammatory subarachnoid hemorrhage.
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Affiliation(s)
- Xiaoli Tan
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Xiaohong Li
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Ruhua Li
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Weiting Meng
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Zhuoxi Xie
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Jing Li
- Department of Cardiology, The 924th Hospital of Chinese People's Liberation Army Joint Service Support Force, Guilin, China
| | - Yeyu Pang
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Guilan Huang
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Li Li
- State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, China.
| | - Hao Li
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China.
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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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Drenthen GS, Elschot EP, van der Knaap N, Uher D, Voorter PHM, Backes WH, Jansen JFA, van der Thiel MM. Imaging Interstitial Fluid With MRI: A Narrative Review on the Associations of Altered Interstitial Fluid With Vascular and Neurodegenerative Abnormalities. J Magn Reson Imaging 2024; 60:40-53. [PMID: 37823526 DOI: 10.1002/jmri.29056] [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: 07/14/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 10/13/2023] Open
Abstract
Interstitial fluid (ISF) refers to the fluid between the parenchymal cells and along the perivascular spaces (PVS). ISF plays a crucial role in delivering nutrients and clearing waste products from the brain. This narrative review focuses on the use of MRI techniques to measure various ISF characteristics in humans. The complementary value of contrast-enhanced and noncontrast-enhanced techniques is highlighted. While contrast-enhanced MRI methods allow measurement of ISF transport and flow, they lack quantitative assessment of ISF properties. Noninvasive MRI techniques, including multi-b-value diffusion imaging, free-water-imaging, T2-decay imaging, and DTI along the PVS, offer promising alternatives to derive ISF measures, such as ISF volume and diffusivity. The emerging role of these MRI techniques in investigating ISF alterations in neurodegenerative diseases (eg, Alzheimer's disease and Parkinson's disease) and cerebrovascular diseases (eg, cerebral small vessel disease and stroke) is discussed. This review also emphasizes current challenges of ISF imaging, such as the microscopic scale at which ISF has to be measured, and discusses potential focus points for future research to overcome these challenges, for example, the use of high-resolution imaging techniques. Noninvasive MRI methods for measuring ISF characteristics hold significant potential and may have a high clinical impact in understanding the pathophysiology of neurodegenerative and cerebrovascular disorders, as well as in evaluating the efficacy of ISF-targeted therapies in clinical trials. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Gerhard S Drenthen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Elles P Elschot
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Noa van der Knaap
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Daniel Uher
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Paulien H M Voorter
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Walter H Backes
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Jacobus F A Jansen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Merel M van der Thiel
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, the Netherlands
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Li J, Jia S, Song Y, Xu W, Lin J. Ginkgolide B can alleviate spinal cord glymphatic system dysfunction and provide neuroprotection in painful diabetic neuropathy rats by inhibiting matrix metalloproteinase-9. Neuropharmacology 2024; 250:109907. [PMID: 38492884 DOI: 10.1016/j.neuropharm.2024.109907] [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: 12/12/2023] [Revised: 03/02/2024] [Accepted: 03/10/2024] [Indexed: 03/18/2024]
Abstract
The glymphatic system plays a crucial role in maintaining optimal central nervous system (CNS) function by facilitating the removal of metabolic wastes. Aquaporin-4 (AQP4) protein, predominantly located on astrocyte end-feet, is a key pathway for metabolic waste excretion. β-Dystroglycan (β-DG) can anchor AQP4 protein to the end-feet membrane of astrocytes and can be cleaved by matrix metalloproteinase (MMP)-9 protein. Studies have demonstrated that hyperglycemia upregulates MMP-9 expression in the nervous system, leading to neuropathic pain. Ginkgolide B (GB) exerts an inhibitory effect on the MMP-9 protein. In this study, we investigated whether inhibition of MMP-9-mediated β-DG cleavage by GB is involved in the regulation of AQP4 polarity within the glymphatic system in painful diabetic neuropathy (PDN) and exerts neuroprotective effects. The PDN model was established by injecting streptozotocin (STZ). Functional changes in the glymphatic system were observed using magnetic resonance imaging (MRI). The paw withdrawal threshold (PWT) was measured to assess mechanical allodynia. The protein expressions of MMP-9, β-DG, and AQP4 were detected by Western blotting and immunofluorescence. Our findings revealed significant decreases in the efficiency of contrast agent clearance within the spinal glymphatic system of the rats, accompanied by decreased PWT, increased MMP-9 protein expression, decreased β-DG protein expression, and loss of AQP4 polarity. Notably, GB treatment demonstrated the capacity to ameliorate spinal cord glymphatic function by modulating AQP4 polarity through MMP-9 inhibition, offering a promising therapeutic avenue for PDN.
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Affiliation(s)
- Jiang Li
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
| | - Shuaiying Jia
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
| | | | - Wenmei Xu
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
| | - Jingyan Lin
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
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Weng N, Wei B, Li G, Yin R, Xin W, Liu C, Li H, Shao C, Jiang T, Wang X. Fluorescence and magnetic resonance imaging of ONL-93 cells in a rat model of ischemic. Magn Reson Imaging 2024; 107:111-119. [PMID: 38185391 DOI: 10.1016/j.mri.2023.12.008] [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: 03/16/2023] [Revised: 07/04/2023] [Accepted: 12/28/2023] [Indexed: 01/09/2024]
Abstract
OBJECTIVES The current methods for detecting myelin changes in ischemic stroke are indirect and cannot accurately reflect their status. This study aimed to develop a novel fluorescent-magnetic resonance dual-modal molecular imaging probe for direct imaging of myelin. METHODS Compounds 7a and 7b were synthesized by linking the MeDAS group and Gadolinium (III) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate. Compound 7a was selected for characterization and further study. Cell uptake, cytotoxicity, and magnetic resonance imaging scans were performed on cells. In vitro experiments on frozen brain sections from 7-day-old, 8-week-old, and ischemic stroke rats were compared with commercially available Luxol Fast Blue staining. After HPLC and MR scanning, brain tissue was soaked in 7a and scanned using T1WI and T1maps sequences. RESULTS Spectrophotometer results showed that compounds 7a and 7b had fluorescent properties. MR scans indicated that the compounds had contrast agent properties. Cells could uptake 7a and exhibited high signals in imaging scans. Compound 7a brain tissue staining showed more fluorescence in myelin-rich regions and identified injury sites in ischemic stroke rats. MR scanning of brain sections provided clear myelin contrast. CONCLUSION A novel fluorescent-magnetic resonance dual-modal molecular imaging probe for direct imaging of myelin was successfully developed and tested in rats with ischemic stroke. These findings provide new insights for the clinical diagnosis of demyelinating diseases.
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Affiliation(s)
- Na Weng
- Department of Nuclear medicine, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China
| | - Bin Wei
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Guodong Li
- Department of Nuclear medicine, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China
| | - Ruijuan Yin
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Wenbin Xin
- Department of Nuclear medicine, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China
| | - Caiyun Liu
- Department of Nuclear medicine, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China
| | - Hao Li
- School of Medical Imaging, Binzhou Medical University, Yantai, Shandong 264003, China
| | - Cuijie Shao
- Medical Research Center, Binzhou Medical University Hospital, Binzhou 256600, China.
| | - Tao Jiang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
| | - Xu Wang
- Department of Nuclear medicine, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China.
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Hlauschek G, Nicolo J, Sinclair B, Law M, Yasuda CL, Cendes F, Lossius MI, Kwan P, Vivash L. Role of the glymphatic system and perivascular spaces as a potential biomarker for post-stroke epilepsy. Epilepsia Open 2024; 9:60-76. [PMID: 38041607 PMCID: PMC10839409 DOI: 10.1002/epi4.12877] [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: 04/03/2023] [Accepted: 11/29/2023] [Indexed: 12/03/2023] Open
Abstract
Stroke is one of the most common causes of acquired epilepsy, which can also result in disability and increased mortality rates particularly in elderly patients. No preventive treatment for post-stroke epilepsy is currently available. Development of such treatments has been greatly limited by the lack of biomarkers to reliably identify high-risk patients. The glymphatic system, including perivascular spaces (PVS), is the brain's waste clearance system, and enlargement or asymmetry of PVS (ePVS) is hypothesized to play a significant role in the pathogenesis of several neurological conditions. In this article, we discuss potential mechanisms for the role of perivascular spaces in the development of post-stroke epilepsy. Using advanced MR-imaging techniques, it has been shown that there is asymmetry and impairment of glymphatic function in the setting of ischemic stroke. Furthermore, studies have described a dysfunction of PVS in patients with different focal and generalized epilepsy syndromes. It is thought that inflammatory processes involving PVS and the blood-brain barrier, impairment of waste clearance, and sustained hypertension affecting the glymphatic system during a seizure may play a crucial role in epileptogenesis post-stroke. We hypothesize that impairment of the glymphatic system and asymmetry and dynamics of ePVS in the course of a stroke contribute to the development of PSE. Automated ePVS detection in stroke patients might thus assist in the identification of high-risk patients for post-stroke epilepsy trials. PLAIN LANGUAGE SUMMARY: Stroke often leads to epilepsy and is one of the main causes of epilepsy in elderly patients, with no preventative treatment available. The brain's waste removal system, called the glymphatic system which consists of perivascular spaces, may be involved. Enlargement or asymmetry of perivascular spaces could play a role in this and can be visualised with advanced brain imaging after a stroke. Detecting enlarged perivascular spaces in stroke patients could help identify those at risk for post-stroke epilepsy.
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Affiliation(s)
- Gernot Hlauschek
- Division of Clinical Neuroscience, National Centre for Epilepsy, member of ERN EpicareOslo University HospitalNorway
- The University of OsloOsloNorway
- Department of Neurosciences, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - John‐Paul Nicolo
- Department of Neurosciences, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of NeurologyThe AlfredMelbourneVictoriaAustralia
- Departments of Medicine and NeurologyThe University of Melbourne, Royal Melbourne HospitalParkvilleVictoriaAustralia
| | - Benjamin Sinclair
- Department of Neurosciences, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of NeurologyThe AlfredMelbourneVictoriaAustralia
| | - Meng Law
- Department of Neurosciences, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of RadiologyThe AlfredMelbourneVictoriaAustralia
| | | | | | - Morten Ingvar Lossius
- Division of Clinical Neuroscience, National Centre for Epilepsy, member of ERN EpicareOslo University HospitalNorway
- The University of OsloOsloNorway
| | - Patrick Kwan
- Department of Neurosciences, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of NeurologyThe AlfredMelbourneVictoriaAustralia
- Departments of Medicine and NeurologyThe University of Melbourne, Royal Melbourne HospitalParkvilleVictoriaAustralia
| | - Lucy Vivash
- Department of Neurosciences, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
- Department of NeurologyThe AlfredMelbourneVictoriaAustralia
- Departments of Medicine and NeurologyThe University of Melbourne, Royal Melbourne HospitalParkvilleVictoriaAustralia
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Al Masri M, Corell A, Michaëlsson I, Jakola AS, Skoglund T. The glymphatic system for neurosurgeons: a scoping review. Neurosurg Rev 2024; 47:61. [PMID: 38253938 PMCID: PMC10803566 DOI: 10.1007/s10143-024-02291-6] [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: 12/07/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 01/24/2024]
Abstract
The discovery of the glymphatic system has revolutionized our understanding of cerebrospinal fluid (CSF) circulation and interstitial waste clearance in the brain. This scoping review aims to synthesize the current literature on the glymphatic system's role in neurosurgical conditions and its potential as a therapeutic target. We conducted a comprehensive search in PubMed and Scopus databases for studies published between January 1, 2012, and October 31, 2023. Studies were selected based on their relevance to neurosurgical conditions and glymphatic function, with both animal and human studies included. Data extraction focused on the methods for quantifying glymphatic function and the main results. A total of 67 articles were included, covering conditions such as idiopathic normal pressure hydrocephalus (iNPH), idiopathic intracranial hypertension (IIH), subarachnoid hemorrhage (SAH), stroke, intracranial tumors, and traumatic brain injury (TBI). Significant glymphatic dysregulation was noted in iNPH and IIH, with evidence of impaired CSF dynamics and delayed clearance. SAH studies indicated glymphatic dysfunction with the potential therapeutic effects of nimodipine and tissue plasminogen activator. In stroke, alterations in glymphatic activity correlated with the extent of edema and neurological recovery. TBI studies highlighted the role of the glymphatic system in post-injury cognitive outcomes. Results indicate that the regulation of aquaporin-4 (AQP4) channels is a critical target for therapeutic intervention. The glymphatic system plays a critical role in the pathophysiology of various neurosurgical conditions, influencing brain edema and CSF dynamics. Targeting the regulation of AQP4 channels presents as a significant therapeutic strategy. Although promising, the translation of these findings into clinical practice requires further human studies. Future research should focus on establishing non-invasive biomarkers for glymphatic function and exploring the long-term effects of glymphatic dysfunction.
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Affiliation(s)
- Mohammad Al Masri
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Alba Corell
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden
| | - Isak Michaëlsson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden
| | - Asgeir S Jakola
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden
| | - Thomas Skoglund
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden.
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Kim E, Van Reet J, Yoo SS. Cerebrospinal fluid solute transport associated with sensorimotor brain activity in rodents. Sci Rep 2023; 13:17002. [PMID: 37813871 PMCID: PMC10562378 DOI: 10.1038/s41598-023-43920-2] [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: 05/24/2023] [Accepted: 09/29/2023] [Indexed: 10/11/2023] Open
Abstract
Cerebrospinal fluid (CSF) is crucial for maintaining neuronal homeostasis, providing nutrition, and removing metabolic waste from the brain. However, the relationship between neuronal activity and CSF solute transport remains poorly understood. To investigate the effect of regional neuronal activity on CSF solute transport, Sprague-Dawley rats (all male, n = 30) under anesthesia received an intracisternal injection of a fluorescent tracer (Texas Red ovalbumin) and were subjected to unilateral electrical stimulation of a forelimb. Two groups (n = 10 each) underwent two different types of stimulation protocols for 90 min, one including intermittent 7.5-s resting periods and the other without rest. The control group was not stimulated. Compared to the control, the stimulation without resting periods led to increased transport across most of the cortical areas, including the ventricles. The group that received intermittent stimulation showed an elevated level of solute uptake in limited areas, i.e., near/within the ventricles and on the ventral brain surface. Interhemispheric differences in CSF solute transport were also found in the cortical regions that overlap with the forelimb sensorimotor area. These findings suggest that neuronal activity may trigger local and brain-wide increases in CSF solute transport, contributing to waste clearance.
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Affiliation(s)
- Evgenii Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Jared Van Reet
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
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Gędek A, Koziorowski D, Szlufik S. Assessment of factors influencing glymphatic activity and implications for clinical medicine. Front Neurol 2023; 14:1232304. [PMID: 37767530 PMCID: PMC10520725 DOI: 10.3389/fneur.2023.1232304] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
The glymphatic system is a highly specialized fluid transport system in the central nervous system. It enables the exchange of the intercellular fluid of the brain, regulation of the movement of this fluid, clearance of unnecessary metabolic products, and, potentially, brain immunity. In this review, based on the latest scientific reports, we present the mechanism of action and function of the glymphatic system and look at the role of factors influencing its activity. Sleep habits, eating patterns, coexisting stress or hypertension, and physical activity can significantly affect glymphatic activity. Modifying them can help to change lives for the better. In the next section of the review, we discuss the connection between the glymphatic system and neurological disorders. Its association with many disease entities suggests that it plays a major role in the physiology of the whole brain, linking many pathophysiological pathways of individual diseases.
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Affiliation(s)
- Adam Gędek
- Department of Neurology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland
- Praski Hospital, Warsaw, Poland
| | - Dariusz Koziorowski
- Department of Neurology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland
| | - Stanisław Szlufik
- Department of Neurology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland
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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] [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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11
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Xu J, Su Y, Fu J, Shen Y, Dong Q, Cheng X. Glymphatic pathway in sporadic cerebral small vessel diseases: From bench to bedside. Ageing Res Rev 2023; 86:101885. [PMID: 36801378 DOI: 10.1016/j.arr.2023.101885] [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: 09/12/2022] [Revised: 02/09/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Cerebral small vessel diseases (CSVD) consist of a group of diseases with high heterogeneity induced by pathologies of intracranial small blood vessels. Endothelium dysfunction, bloodbrain barrier leakage and the inflammatory response are traditionally considered to participate in the pathogenesis of CSVD. However, these features cannot fully explain the complex syndrome and related neuroimaging characteristics. In recent years, the glymphatic pathway has been discovered to play a pivotal role in clearing perivascular fluid and metabolic solutes, which has provided novel insights into neurological disorders. Researchers have also explored the potential role of perivascular clearance dysfunction in CSVD. In this review, we presented a brief overview of CSVD and the glymphatic pathway. In addition, we elucidated CSVD pathogenesis from the perspective of glymphatic failure, including basic animal models and clinical neuroimaging markers. Finally, we proposed forthcoming clinical applications targeting the glymphatic pathway, hoping to provide novel ideas on promising therapies and preventions of CSVD.
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Affiliation(s)
- Jiajie Xu
- Department of Neurology, National Center for Neurological Disorders, National Clinical Research Centre for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ya Su
- Department of Neurology, National Center for Neurological Disorders, National Clinical Research Centre for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiayu Fu
- Department of Neurology, National Center for Neurological Disorders, National Clinical Research Centre for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yong Shen
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC and Neurodegenerative Disorder Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qiang Dong
- Department of Neurology, National Center for Neurological Disorders, National Clinical Research Centre for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Xin Cheng
- Department of Neurology, National Center for Neurological Disorders, National Clinical Research Centre for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.
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12
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Qin Y, Li X, Qiao Y, Zou H, Qian Y, Li X, Zhu Y, Huo W, Wang L, Zhang M. DTI-ALPS: An MR biomarker for motor dysfunction in patients with subacute ischemic stroke. Front Neurosci 2023; 17:1132393. [PMID: 37065921 PMCID: PMC10102345 DOI: 10.3389/fnins.2023.1132393] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/03/2023] [Indexed: 04/03/2023] Open
Abstract
PurposeBrain glymphatic dysfunction is involved in the pathologic process of acute ischemic stroke (IS). The relationship between brain glymphatic activity and dysfunction in subacute IS has not been fully elucidated. Diffusion tensor image analysis along the perivascular space (DTI-ALPS) index was used in this study to explore whether glymphatic activity was related to motor dysfunction in subacute IS patients.MethodsTwenty-six subacute IS patients with a single lesion in the left subcortical region and 32 healthy controls (HCs) were recruited in this study. The DTI-ALPS index and DTI metrics (fractional anisotropy, FA, and mean diffusivity, MD) were compared within and between groups. Spearman's and Pearson's partial correlation analyses were performed to analyze the relationships of the DTI-ALPS index with Fugl-Meyer assessment (FMA) scores and with corticospinal tract (CST) integrity in the IS group, respectively.ResultsSix IS patients and two HCs were excluded. The left DTI-ALPS index of the IS group was significantly lower than that of the HC group (t = −3.02, p = 0.004). In the IS group, a positive correlation between the left DTI-ALPS index and the simple Fugl-Meyer motor function score (ρ = 0.52, p = 0.019) and a significant negative correlation between the left DTI-ALPS index and the FA (R = −0.55, p = 0.023) and MD (R = −0.48, p = 0.032) values of the right CST were found.ConclusionsGlymphatic dysfunction is involved in subacute IS. DTI-ALPS could be a potential magnetic resonance (MR) biomarker of motor dysfunction in subacute IS patients. These findings contribute to a better understanding of the pathophysiological mechanisms of IS and provide a new target for alternative treatments for IS.
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Affiliation(s)
- Yue Qin
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Xin Li
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Yanqiang Qiao
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Huili Zou
- Department of Rehabilitation Medicine, Xi'an Daxing Hospital, Xi'an, China
| | - Yifan Qian
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Xiaoshi Li
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Yinhu Zhu
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Wenli Huo
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Lei Wang
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
- Lei Wang
| | - Ming Zhang
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- *Correspondence: Ming Zhang
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13
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Yan JH, Wang YJ, Sun YR, Pei YH, Ma HW, Mu YK, Qin LH. The lymphatic drainage systems in the brain: a novel target for ischemic stroke? Neural Regen Res 2023; 18:485-491. [DOI: 10.4103/1673-5374.346484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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14
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Yi T, Gao P, Hou M, Lv H, Huang M, Gao S, He J, Yang D, Chen W, Zhu T, Yu C, Liu F, Yin H, Jin S. The mechanisms underlying the actions of Xuefu Zhuyu decoction pretreatment against neurological deficits after ischemic stroke in mice: The mediation of glymphatic function by aquaporin-4 and its anchoring proteins. Front Pharmacol 2022; 13:1053253. [PMID: 36582539 PMCID: PMC9792381 DOI: 10.3389/fphar.2022.1053253] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022] Open
Abstract
Ischemic stroke (IS) has been associated with an impairment in glymphatic function. Xuefu Zhuyu Decoction (XFZYD) is widely used in the prevention and treatment of ischemic stroke. We hypothesized that Xuefu Zhuyu decoction pretreatment could attenuate early neurological deficits after ischemic stroke by enhancing the function of the glymphatic system. To prove our hypothesis, we carried out temporary middle cerebral artery occlusion and reperfusion surgery on C57BL/6 mice and then measured neurological score, infarct size and performed hematoxylin-eosin staining to assess stroke outcomes after 24 h of reperfusion. Subsequently, we injected fluorescent tracers in to the cisterna magna and evaluated tracer distribution in coronal brain sections. The polarization of aquaporin-4 (AQP4), colocalization of aquaporin-4, α-dystroglycan, β-dystroglycan and agrin were determined by immunofluorescence. Our research showed that pretreatment with Xuefu Zhuyu decoction significantly alleviated neurological scores, neurological deficits and pathological abnormalities in a mouse model of ischemic stroke. Importantly, Xuefu Zhuyu decoction pretreatment enhanced cerebrospinal fluid influx, protected aquaporin-4 depolarization and promoted the colocalization of aquaporin-4 with its anchoring proteins in the brain. Our findings highlight novel mechanisms underlying the neuroprotective effect of Xuefu Zhuyu decoction pretreatment on ischemic stroke-induced brain damage through the glymphatic system. Xuefu Zhuyu decoction pretreatment may offer a promising approach to slow the onset and progression of ischemic stroke.
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Affiliation(s)
- Ting Yi
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ping Gao
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Meng Hou
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Huan Lv
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mengyuan Huang
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Shanshan Gao
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jinrong He
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dongdong Yang
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Weiyin Chen
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Tianmin Zhu
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Chang Yu
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fuyou Liu
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Haiyan Yin
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Haiyan Yin, ; Shuoguo Jin,
| | - Shuoguo Jin
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Haiyan Yin, ; Shuoguo Jin,
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15
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Xu Y, Cheng L, Yuan L, Yi Q, Xiao L, Chen H. Progress on Brain and Ocular Lymphatic System. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6413553. [PMID: 36425338 PMCID: PMC9681545 DOI: 10.1155/2022/6413553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/11/2022] [Accepted: 10/26/2022] [Indexed: 02/06/2024]
Abstract
In recent years, 2 major discoveries have modified the traditional understanding of the brain. First, meningeal lymphatic vessels (MLV) were found in the dural sinus, which may absorb and drain cerebrospinal fluid (CSF). Second, the glymphatic system was discovered, composed of para-arterial CSF influx channel, paravenous interstitial fluid (ISF) efflux channel, and the water channel aquaporin-4 (AQP4) in astrocytes connecting the 2 channels. Accumulating evidence demonstrates that the lymphatic system of the brain plays a vital role within the circulation of CSF and, therefore, in the removal of metabolites. Therefore, it is involved in the incidence and development of some central nervous system (CNS) diseases. The optic nerve and retina are the extension of the CNS in the orbit. Whether they have a lymphatic system and how they clear the metabolites of the optic nerve and retina are still unclear. Recent studies have found that the ocular lymphatic system has a crucial impact on bounding eye diseases, like disorders of the optic nerve and retina. Therefore, here we review the recent research progress concerning the structure and function of MLV and glymphatic system. We also discuss the biomarkers for identification of lymphatic vessels, the composition of ocular lymphatic systems, and the possible association with diseases.
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Affiliation(s)
- Yang Xu
- Eye School of Chengdu University of TCM, Chengdu, China
- Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, China
| | - Lu Cheng
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Lu Yuan
- Eye School of Chengdu University of TCM, Chengdu, China
- Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, China
| | - Qianya Yi
- Eye School of Chengdu University of TCM, Chengdu, China
- Key Laboratory of Sichuan Province Ophthalmopathy Prevention & Cure and Visual Function Protection, China
| | - Liuyi Xiao
- University of Electronic Science and Technology of China, Chengdu, China
| | - Hui Chen
- Eye School of Chengdu University of TCM, Chengdu, China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- University of Electronic Science and Technology of China, Chengdu, China
- University of Shanghai for Science and Technology, Shanghai, China
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16
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Li C, Lin L, Sun C, Hao X, Yin L, Zhang X, Tian J, Yao Z, Feng X, Yang Y. Glymphatic system in the thalamus, secondary degeneration area was severely impaired at 2nd week after transient occlusion of the middle cerebral artery in rats. Front Neurosci 2022; 16:997743. [PMID: 36278004 PMCID: PMC9582259 DOI: 10.3389/fnins.2022.997743] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/21/2022] [Indexed: 11/22/2022] Open
Abstract
Background and objectives The glymphatic system is a recently discovered cerebrospinal fluid transport system and little is known about its dynamic changes after stroke. This study aimed to dynamically observe the structural and functional changes of the impaired glymphatic system in the thalamus after ischemic stroke by pathology and MRI. Materials and methods Ischemic stroke was induced by the middle cerebral artery occlusion (MCAO) model. A total of 20 Sprague-Dawley rats were randomly assigned into four groups: sham, MCAO 1 week, MCAO 2 week, and MCAO 2 month. All rats successively underwent neurological examination, dynamic contrast-enhanced MRI (DCE-MRI), and immunofluorescence staining. Immunofluorescence staining of glial fibrillary acidic protein (GFAP), aquaporin-4 (AQP4), ionized calcium-binding adaptor molecule 1 (Iba1), and beta-amyloid precursor protein (APP) were done in thalamus ventroposterior nucleus. Results The astrocyte and microglial activation and the APP deposition in the MCAO 2 week group were the highest (P < 0.05 for all). The AQP4 polarization rates of the MCAO 2 week and 2 month groups were the lowest (P < 0.05 for all). Although there was no correlation between histological changes and MRI metrics in all four groups (P > 0.05 for all), the tendency of the APP deposition was nearly consistent with the one of the contrast agent retention in DCE-MRI. Conclusion The glymphatic system in the thalamus was severely impaired at 2nd week after MCAO, and may be revealed by DCE-MRI. This study may provide a relevant theoretical basis for making a thorough inquiry of the mechanism of brain injury after stroke and clinical treatment of ischemic stroke and help readers appreciate the importance of DCE-MRI.
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Affiliation(s)
- Chanchan Li
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Luyi Lin
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
- Department of Radiology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Chengfeng Sun
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaozhu Hao
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Lekang Yin
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaoxue Zhang
- Department of Radiotherapy, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, China
| | - Jiaqi Tian
- Department of Radiology, Renji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Zhengwei Yao
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaoyuan Feng
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yanmei Yang
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Yanmei Yang,
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17
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Choi S, Jang DC, Chung G, Kim SK. Transcutaneous Auricular Vagus Nerve Stimulation Enhances Cerebrospinal Fluid Circulation and Restores Cognitive Function in the Rodent Model of Vascular Cognitive Impairment. Cells 2022; 11:cells11193019. [PMID: 36230988 PMCID: PMC9564197 DOI: 10.3390/cells11193019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Vascular cognitive impairment (VCI) is a common sequela of cerebrovascular disorders. Although transcutaneous auricular vagus nerve stimulation (taVNS) has been considered a complementary treatment for various cognitive disorders, preclinical data on the effect of taVNS on VCI and its mechanism remain ambiguous. To measure cerebrospinal fluid (CSF) circulation during taVNS, we used in vivo two-photon microscopy with CSF and vasculature tracers. VCI was induced by transient bilateral common carotid artery occlusion (tBCCAO) surgery in mice. The animals underwent anesthesia, off-site stimulation, or taVNS for 20 min. Cognitive tests, including the novel object recognition and the Y-maze tests, were performed 24 h after the last treatment. The long-term treatment group received 6 days of treatment and was tested on day 7; the short-term treatment group received 2 days of treatment and was tested 3 days after tBCCAO surgery. CSF circulation increased remarkably in the taVNS group, but not in the anesthesia-control or off-site-stimulation-control groups. The cognitive impairment induced by tBCCAO was significantly restored after both long- and short-term taVNS. In terms of effects, both long- and short-term stimulations showed similar recovery effects. Our findings provide evidence that taVNS can facilitate CSF circulation and that repetitive taVNS can ameliorate VCI symptoms.
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Affiliation(s)
- Seunghwan Choi
- Department of East-West Medicine, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Dong Cheol Jang
- Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Geehoon Chung
- Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Sun Kwang Kim
- Department of East-West Medicine, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Correspondence:
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18
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Yoo SS, Kim HC, Kim J, Kim E, Kowsari K, Van Reet J, Yoon K. Enhancement of cerebrospinal fluid tracer movement by the application of pulsed transcranial focused ultrasound. Sci Rep 2022; 12:12940. [PMID: 35902724 PMCID: PMC9334279 DOI: 10.1038/s41598-022-17314-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/25/2022] [Indexed: 11/10/2022] Open
Abstract
Efficient transport of solutes in the cerebrospinal fluid (CSF) plays a critical role in their clearance from the brain. Convective bulk flow of solutes in the CSF in the perivascular space (PVS) is considered one of the important mechanisms behind solute movement in the brain, before their ultimate drainage to the systemic lymphatic system. Acoustic pressure waves can impose radiation force on a medium in its path, inducing localized and directional fluidic flow, known as acoustic streaming. We transcranially applied low-intensity focused ultrasound (FUS) to rats that received an intracisternal injection of fluorescent CSF tracers (dextran and ovalbumin, having two different molecular weights-Mw). The sonication pulsing parameter was determined on the set that propelled the aqueous solution of toluidine blue O dye into a porous media (melamine foam) at the highest level of infiltration. Fluorescence imaging of the brain showed that application of FUS increased the uptake of ovalbumin at the sonicated plane, particularly around the ventricles, whereas the uptake of high-Mw dextran was unaffected. Numerical simulation showed that the effects of sonication were non-thermal. Sonication did not alter the animals' behavior or disrupt the blood-brain barrier (BBB) while yielding normal brain histology. The results suggest that FUS may serve as a new non-invasive means to promote interstitial CSF solute transport in a region-specific manner without disrupting the BBB, providing potential for enhanced clearance of waste products from the brain.
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Affiliation(s)
- Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
| | - Hyun-Chul Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
- Department of Artificial Intelligence, Kyungpook National University, Daegu, Republic of Korea
| | - Jaeho Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
- Department of Neurology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong-si, Gyeonggi-do, Republic of Korea
| | - Evgenii Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Kavin Kowsari
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Boston, MA, USA
| | - Jared Van Reet
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Kyungho Yoon
- School of Mathematics and Computing (Computational Science and Engineering), Yonsei University, Seoul, Republic of Korea
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Sun C, Lin L, Yin L, Hao X, Tian J, Zhang X, Ren Y, Li C, Yang Y. Acutely Inhibiting AQP4 With TGN-020 Improves Functional Outcome by Attenuating Edema and Peri-Infarct Astrogliosis After Cerebral Ischemia. Front Immunol 2022; 13:870029. [PMID: 35592320 PMCID: PMC9110854 DOI: 10.3389/fimmu.2022.870029] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 04/11/2022] [Indexed: 01/05/2023] Open
Abstract
Background Ischemic stroke is one of the leading causes of human death and disability. Brain edema and peri-infarct astrocyte reactivity are crucial pathological changes, both involving aquaporin-4 (AQP4). Studies revealed that acute inhibition of AQP4 after stroke diminishes brain edema, however, its effect on peri-infarct astrocyte reactivity and the subacute outcome is unclear. And if diffusion-weighted imaging (DWI) could reflect the AQP4 expression patterns is uncertain. Methods Rats were subjected to middle cerebral artery occlusion (MCAO) and allocated randomly to TGN 020-treated and control groups. One day after stroke, brain swelling and lesion volumes of the rats were checked using T2-weighted imaging (T2-WI). Fourteen days after stroke, the rats successively underwent neurological examination, T2-WI and DWI with standard b-values and ultra-high b-values, apparent diffusion coefficient (ADC) was calculated correspondingly. Finally, the rats’ brains were acquired and used for glial fibrillary acidic protein (GFAP) and AQP4 immunoreactive analysis. Results At 1 day after stroke, the TGN-020-treated animals exhibited reduced brain swelling and lesion volumes compared with those in the control group. At 14 days after stroke, the TGN-020-treated animals showed fewer neurological function deficits and smaller lesion volumes. In the peri-infarct region, the control group showed evident astrogliosis and AQP4 depolarization, which were reduced significantly in the TGN-020 group. In addition, the ultra-high b-values of ADC (ADCuh) in the peri-infarct region of the TGN-020 group was higher than that of the control group. Furthermore, correlation analysis revealed that peri-infarct AQP4 polarization correlated negatively with astrogliosis extent, and ADCuh correlated positively with AQP4 polarization. Conclusion We found that acutely inhibiting AQP4 using TGN-020 promoted neurological recovery by diminishing brain edema at the early stage and attenuating peri-infarct astrogliosis and AQP4 depolarization at the subacute stage after stroke. Moreover, ADCuh could reflect the AQP4 polarization.
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Affiliation(s)
- Chengfeng Sun
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Luyi Lin
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Lekang Yin
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaozhu Hao
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiaqi Tian
- Department of Radiology, Renji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaoxue Zhang
- Department of Radiotherapy, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, China
| | - Yan Ren
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chanchan Li
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yanmei Yang
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China
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20
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Zhang D, Li X, Li B. Glymphatic System Dysfunction in Central Nervous System Diseases and Mood Disorders. Front Aging Neurosci 2022; 14:873697. [PMID: 35547631 PMCID: PMC9082304 DOI: 10.3389/fnagi.2022.873697] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/31/2022] [Indexed: 12/13/2022] Open
Abstract
The glymphatic system, a recently discovered macroscopic waste removal system in the brain, has many unknown aspects, especially its driving forces and relationship with sleep, and thus further explorations of the relationship between the glymphatic system and a variety of possible related diseases are urgently needed. Here, we focus on the progress in current research on the role of the glymphatic system in several common central nervous system diseases and mood disorders, discuss the structural and functional abnormalities of the glymphatic system which may occur before or during the pathophysiological progress and the possible underlying mechanisms. We emphasize the relationship between sleep and the glymphatic system under pathological conditions and summarize the common imaging techniques for the glymphatic system currently available. The perfection of the glymphatic system hypothesis and the exploration of the effects of aging and endocrine factors on the central and peripheral regulatory pathways through the glymphatic system still require exploration in the future.
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Affiliation(s)
- Dianjun Zhang
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Liaoning Province Key Laboratory of Forensic Bio-evidence Sciences, School of Forensic Medicine, China Medical University, Shenyang, China
- China Medical University Center of Forensic Investigation, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Xinyu Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Liaoning Province Key Laboratory of Forensic Bio-evidence Sciences, School of Forensic Medicine, China Medical University, Shenyang, China
- China Medical University Center of Forensic Investigation, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Liaoning Province Key Laboratory of Forensic Bio-evidence Sciences, School of Forensic Medicine, China Medical University, Shenyang, China
- China Medical University Center of Forensic Investigation, School of Forensic Medicine, China Medical University, Shenyang, China
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21
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Kaur M, Sharma S. Molecular mechanisms of cognitive impairment associated with stroke. Metab Brain Dis 2022; 37:279-287. [PMID: 35029798 DOI: 10.1007/s11011-022-00901-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/03/2022] [Indexed: 10/19/2022]
Abstract
Stroke is the second leading cause of death after coronary heart disease in developed countries and is the greatest cause of disability and cognitive impairment. Risk factors for cognitive impairment and dementia after stroke are multifactorial including older age, family history, hypertension, arterial fibrillation, diabetes, genetic variants, low educational status, vascular comorbidities, prior transient ischaemic attack or recurrent stroke, depressive illness duration of a stroke, location, volume, intensity, and degree of neuronal degeneration, location and size of infarction after stroke, time interval after stroke other cerebral dysfunctions. The pathophysiology of stroke associated cognitive impairment is complex and recent molecular, cellular, and animal models studies have revealed that multiple cellular changes have been implicated, including altered redox state, mitochondrial dysfunction, disruption of the blood-brain barrier, perivascular spacing, glymphatic system impairment, microglia activation and amyloid-β deposition in the parenchyma of the brain. These studies have also evidenced the involvement of various transcription factors, intracellular adhesion molecules, and endogenous growth factors in the pathogenesis of cognitive impairment associated with stroke and providing scope for developing therapeutic strategies for treatment. This review summarizes the latest research findings on molecular mechanisms involved in cognitive impairment associated with stroke.
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Affiliation(s)
- Mandeep Kaur
- Department of Pharmacology, School of Pharmaceutical Sciences, CT University, Ludhiana, Punjab, India
| | - Saurabh Sharma
- School of Pharmaceutical Sciences, CT University, Ludhiana, Punjab, India.
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22
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Liu X, Wu G, Tang N, Li L, Liu C, Wang F, Ke S. Glymphatic Drainage Blocking Aggravates Brain Edema, Neuroinflammation via Modulating TNF-α, IL-10, and AQP4 After Intracerebral Hemorrhage in Rats. Front Cell Neurosci 2022; 15:784154. [PMID: 34975411 PMCID: PMC8718698 DOI: 10.3389/fncel.2021.784154] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/01/2021] [Indexed: 11/17/2022] Open
Abstract
Objective: The “Glymphatic” system, a network of perivascular tunnels wrapped by astrocyte endfeet, was reported to be closely associated with the diseases of the central nervous system. Here, we investigated the role of the glymphatic system in intracerebral hemorrhage (ICH) and its protective mechanism. Method: Experimental ICH model was induced by type IV collagenase in rats. Cerebral lymphatic blockage was induced by ligation and removal of cervical lymph nodes. The experimental rats were divided into sham-operated (SO) group, ICH group, and cerebral lymphatic blocking and ICH (ICH + CLB) group. Neurological scores were measured using the Garcia scoring system on the third and seventh day after ICH. Active caspase-3 was immunostained to evaluate neuronal apoptosis. Brain water content was calculated using the dry-wet specific gravity method. The expression of inflammatory factors TNF-α, IL-1β, and IL-10 were detected using ELISA. Aquaporins-4 (AQP-4) and glial fibrillary acidic protein (GFAP) were detected using western blot analysis. Results: The neurological scores of rats in the CLB + ICH group were significantly lower than those in the in ICH group. The number of active caspase-3 neurons was significantly higher in the CLB + ICH group compared to the ICH group. CLB significantly aggravated ICH-induced brain edema 3 d after ICH. There was an increase in the expression of TNF-α, IL-1β, IL-10, AQP-4, GFAP after ICH. The expression of TNF-α was significantly higher in the CLB + ICH group compared to ICH group 3 d after ICH while there was no difference 7 d after ICH. There was no statistical difference in the expression of IL-1β between the ICH group and CLB + ICH group. However, the expression of IL-10 in the CLB + ICH group was significantly lower than that in the ICH group. Lastly, AQP-4 expression was significantly lower in the CLB + ICH group compared to the ICH group while the expression of GFAP was higher in the CLB + ICH group compared to the ICH group. Conclusion: CLB exacerbated cerebral edema, neuroinflammation, neuronal apoptosis and caused neurological deficits in rats with ICH via down-regulating AQP-4, up-regulating inflammatory TNF-α and inhibiting IL-10 expression. The glymphatic drainage system protects against neurologic injury after ICH induction in rats under normal physiological conditions.
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Affiliation(s)
- Xichang Liu
- Department of Neurology, First People's Hospital of Yichang, Yichang, China
| | - Gang Wu
- Department of Pharmacy, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Na Tang
- Department of Neurology, First People's Hospital of Yichang, Yichang, China
| | - Li Li
- Department of Neurology, First People's Hospital of Yichang, Yichang, China
| | - Cuimin Liu
- Department of Pharmacy, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Feng Wang
- Department of Neurology, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Shaofa Ke
- Department of Neurology, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
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23
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Glymphatic system dysfunction in obstructive sleep apnea evidenced by DTI-ALPS. Sleep Med 2021; 89:176-181. [PMID: 35030357 DOI: 10.1016/j.sleep.2021.12.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/13/2021] [Accepted: 12/20/2021] [Indexed: 12/25/2022]
Abstract
OBJECTIVES This study aimed to evaluate the glymphatic system function in patients with obstructive sleep apnea (OSA) compared to healthy controls using diffusion tensor imaging (DTI) with the perivascular space (DTI-ALPS) method. Our hypothesis is that patients with OSA may have glymphatic system dysfunction, which is correlated with OSA severity. METHODS We enrolled 24 patients with OSA and 24 healthy controls. All participants underwent DTI magnetic resonance imaging (MRI) using the same 3T MRI scanner, and we calculated the DTI-ALPS index from the DTI. We evaluated the differences in the DTI-ALPS index between patients with OSA and healthy controls. In addition, we conducted a correlation analysis between the DTI-ALPS index and clinical characteristics. RESULTS The DTI-ALPS index was significantly different between the groups. The DTI-ALPS in patients with OSA was significantly lower than in healthy controls (1.30450 vs. 1.61600, p = 0.0006). Furthermore, the DTI-ALPS index was significantly negatively correlated with the apnea-hypopnea index in sleep stage N (r = -0.427, p = 0.042) and oxygen desaturation index during sleep N (r = -0.497, p = 0.036). CONCLUSION We successfully demonstrated glymphatic system dysfunction in patients with OSA. In addition, glymphatic system dysfunction is well correlated with OSA severity, especially during sleep stage N. Thus, these findings can explain the effects of OSA on increased risk of developing dementia and highlight the importance of OSA treatment.
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24
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Stuckey SM, Ong LK, Collins-Praino LE, Turner RJ. Neuroinflammation as a Key Driver of Secondary Neurodegeneration Following Stroke? Int J Mol Sci 2021; 22:ijms222313101. [PMID: 34884906 PMCID: PMC8658328 DOI: 10.3390/ijms222313101] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 01/13/2023] Open
Abstract
Ischaemic stroke involves the rapid onset of focal neurological dysfunction, most commonly due to an arterial blockage in a specific region of the brain. Stroke is a leading cause of death and common cause of disability, with over 17 million people worldwide suffering from a stroke each year. It is now well-documented that neuroinflammation and immune mediators play a key role in acute and long-term neuronal tissue damage and healing, not only in the infarct core but also in distal regions. Importantly, in these distal regions, termed sites of secondary neurodegeneration (SND), spikes in neuroinflammation may be seen sometime after the initial stroke onset, but prior to the presence of the neuronal tissue damage within these regions. However, it is key to acknowledge that, despite the mounting information describing neuroinflammation following ischaemic stroke, the exact mechanisms whereby inflammatory cells and their mediators drive stroke-induced neuroinflammation are still not fully understood. As a result, current anti-inflammatory treatments have failed to show efficacy in clinical trials. In this review we discuss the complexities of post-stroke neuroinflammation, specifically how it affects neuronal tissue and post-stroke outcome acutely, chronically, and in sites of SND. We then discuss current and previously assessed anti-inflammatory therapies, with a particular focus on how failed anti-inflammatories may be repurposed to target SND-associated neuroinflammation.
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Affiliation(s)
- Shannon M. Stuckey
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
| | - Lin Kooi Ong
- School of Pharmacy, Monash University Malaysia, Subang Jaya 47500, Malaysia;
- School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, The University of Newcastle, Callaghan 2308, Australia
| | - Lyndsey E. Collins-Praino
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
| | - Renée J. Turner
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
- Correspondence: ; Tel.: +61-8-8313-3114
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25
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Toh CH, Siow TY. Glymphatic Dysfunction in Patients With Ischemic Stroke. Front Aging Neurosci 2021; 13:756249. [PMID: 34819849 PMCID: PMC8606520 DOI: 10.3389/fnagi.2021.756249] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022] Open
Abstract
Objectives: Rodent experiments have provided some insight into the changes of glymphatic function in ischemic stroke. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) method offers an opportunity for the noninvasive investigation of the glymphatic system in patients with ischemic stroke. We aimed to investigate the changes of glymphatic function in ischemic stroke and the factors associated with the changes. Materials and Methods: A total of 50 patients (mean age 56.7 years; 30 men) and 44 normal subjects (mean age 53.3 years; 23 men) who had preoperative diffusion-tensor imaging for calculation of the analysis along the perivascular space (ALPS) index were retrospectively included. Information collected from each patient included sex, age, time since stroke onset, infarct location, hemorrhagic change, infarct volume, infarct apparent diffusion coefficient (ADC), infarct fractional anisotropy (FA), and ALPS index of both hemispheres. Interhemispheric differences in ALPS index (infarct side vs. contralateral normal side) were assessed with a paired t-test in all patients. ALPS index was normalized by calculating ALPS ratios (right-to-left and left-to-right) for comparisons between patients and normal subjects. Comparisons of ALPS ratios between patients and normal subjects were performed using analysis of covariance with adjustments for age and sex. Linear regression analyses were performed to identify factors associated with the ALPS index. Results: In patients, the mean ALPS index ipsilateral to infarct was 1.162 ± 0.126, significantly lower (P < 0.001) than that of the contralateral side (1.335 ± 0.160). The right-to-left ALPS index ratio of patients with right cerebral infarct was 0.84 ± 0.08, significantly lower (P < 0.001) than that of normal subjects (0.95 ± 0.07). The left-to-right ALPS ratio of patients with left cerebral infarct was 0.92 ± 0.09, significantly (P < 0.001) lower than that of normal subjects (1.05 ± 0.08). On multiple linear regression analysis, time since stroke onset (β = 0.794, P < 0.001) was the only factor associated with the ALPS index. Conclusion: The ALPS index showed lower values in ischemic stroke suggesting impaired glymphatic function. Following initial impairment, the ALPS index increased with the time since stroke onset, which is suggestive of glymphatic function recovery.
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Affiliation(s)
- Cheng Hong Toh
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Tiing Yee Siow
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
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26
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Liu K, Zhu J, Chang Y, Lin Z, Shi Z, Li X, Chen X, Lin C, Pan S, Huang K. Attenuation of cerebral edema facilitates recovery of glymphatic system function after status epilepticus. JCI Insight 2021; 6:e151835. [PMID: 34494549 PMCID: PMC8492308 DOI: 10.1172/jci.insight.151835] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/15/2021] [Indexed: 11/17/2022] Open
Abstract
Status epilepticus (SE) is a neurological emergency usually accompanied by acute cerebral edema and long-term cognitive impairment, and is characterized by neurodegeneration and aberrant hyperphosphorylated tau protein (p-tau) aggregation. The glia-lymphatic (glymphatic) system plays a central role in facilitating the clearance of metabolic waste from the brain, but its relationship with cerebral edema and cognitive dysfunction after SE is unclear. We hypothesized that cerebral edema after SE might impair glymphatic system function through compression, thus leading to impaired removal of metabolic waste, and ultimately affecting long-term cognitive function. Our results showed that glymphatic system function was temporarily impaired, as evidenced by 2-photon imaging, MRI enhancement, imaging of brain sections, and astrocytic water channel aquaporin 4 (AQP4) protein polarization. The severity of cerebral edema on MRI correlated well with glymphatic system dysfunction within 8 days following SE. Moreover, when cerebral edema was alleviated by glibenclamide treatment or genetic deletion of Trpm4, post-SE glymphatic system function recovered earlier, along with fewer p-tau–deposited neurons and neuronal degeneration and better cognitive function. These findings suggest that SE-induced cerebral edema may cause glymphatic system dysfunction and render the post-SE brain vulnerable to p-tau aggregation and neurocognitive impairment.
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Affiliation(s)
- Kewei Liu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Juan Zhu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yuan Chang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhenzhou Lin
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhu Shi
- Department of Neurology, Dongguan Hospital, Southern Medical University, Dongguan, China
| | - Xing Li
- Department of Neurology, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Xing Chen
- Department of Neurology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Chuman Lin
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Suyue Pan
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Kaibin Huang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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27
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Lv T, Zhao B, Hu Q, Zhang X. The Glymphatic System: A Novel Therapeutic Target for Stroke Treatment. Front Aging Neurosci 2021; 13:689098. [PMID: 34305569 PMCID: PMC8297504 DOI: 10.3389/fnagi.2021.689098] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/07/2021] [Indexed: 12/25/2022] Open
Abstract
The glymphatic system (GS) is a novel defined brain-wide perivascular transit network between cerebrospinal fluid (CSF) and interstitial solutes that facilitates the clearance of brain metabolic wastes. The complicated network of the GS consists of the periarterial CSF influx pathway, astrocytes-mediated convective transport of fluid and solutes supported by AQP4 water channels, and perivenous efflux pathway. Recent researches indicate that the GS dysfunction is associated with various neurological disorders, including traumatic brain injury, hydrocephalus, epilepsy, migraine, and Alzheimer’s disease (AD). Meanwhile, the GS also plays a pivotal role in the pathophysiological process of stroke, including brain edema, blood–brain barrier (BBB) disruption, immune cell infiltration, neuroinflammation, and neuronal apoptosis. In this review, we illustrated the key anatomical structures of the GS, the relationship between the GS and the meningeal lymphatic system, the interaction between the GS and the BBB, and the crosstalk between astrocytes and other GS cellular components. In addition, we contributed to the current knowledge about the role of the GS in the pathology of stroke and the role of AQP4 in stroke. We further discussed the potential use of the GS in early risk assessment, diagnostics, prognostics, and therapeutics of stroke.
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Affiliation(s)
- Tao Lv
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Bing Zhao
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Hu
- Central Laboratory, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaohua Zhang
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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28
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Raitamaa L, Huotari N, Korhonen V, Helakari H, Koivula A, Kananen J, Kiviniemi V. Spectral analysis of physiological brain pulsations affecting the BOLD signal. Hum Brain Mapp 2021; 42:4298-4313. [PMID: 34037278 PMCID: PMC8356994 DOI: 10.1002/hbm.25547] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/17/2022] Open
Abstract
Physiological pulsations have been shown to affect the global blood oxygen level dependent (BOLD) signal in human brain. While these pulsations have previously been regarded as noise, recent studies show their potential as biomarkers of brain pathology. We used the extended 5 Hz spectral range of magnetic resonance encephalography (MREG) data to investigate spatial and frequency distributions of physiological BOLD signal sources. Amplitude spectra of the global image signals revealed cardiorespiratory envelope modulation (CREM) peaks, in addition to the previously known very low frequency (VLF) and cardiorespiratory pulsations. We then proceeded to extend the amplitude of low frequency fluctuations (ALFF) method to each of these pulsations. The respiratory pulsations were spatially dominating over most brain structures. The VLF pulsations overcame the respiratory pulsations in frontal and parietal gray matter, whereas cardiac and CREM pulsations had this effect in central cerebrospinal fluid (CSF) spaces and major blood vessels. A quasi‐periodic pattern (QPP) analysis showed that the CREM pulsations propagated as waves, with a spatiotemporal pattern differing from that of respiratory pulsations, indicating them to be distinct intracranial physiological phenomenon. In conclusion, the respiration has a dominant effect on the global BOLD signal and directly modulates cardiovascular brain pulsations.
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Affiliation(s)
- Lauri Raitamaa
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
| | - Niko Huotari
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
| | - Vesa Korhonen
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
| | - Heta Helakari
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
| | - Anssi Koivula
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
| | - Janne Kananen
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
| | - Vesa Kiviniemi
- Oulu Functional Neuro Imaging Group, Research Unit of Medical Imaging Physics and Technology (MIPT), University of Oulu, Oulu.,Department of Diagnostic Radiology, Medical Research Center (MRC), Oulu University Hospital, Oulu
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29
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Ji C, Yu X, Xu W, Lenahan C, Tu S, Shao A. The role of glymphatic system in the cerebral edema formation after ischemic stroke. Exp Neurol 2021; 340:113685. [PMID: 33676917 DOI: 10.1016/j.expneurol.2021.113685] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 12/20/2022]
Abstract
Cerebral edema following ischemic stroke is predictive of the severity of the eventual stroke related damage, however the effective treatment is limited. The glymphatic system is a recently identified waste clearance pathway in the brain, found in the paravascular space and mainly composed of astrocytes and their aquaporin-4 (AQP4) water channels. In this review, we primarily focus on the role of the glymphatic system in the formation of cerebral edema after ischemic stroke. There is still no definite conclusion whether the influx of cerebrospinal fluid (CSF) in the glymphatic system is increased or not after ischemic stroke. However, the reduced interstitial fluid (ISF) clearance after ischemic stroke is definite. Additionally, AQP4 as the most important part of glymphatic system plays a complex bimodal in cerebral edema after ischemic stroke. Most of the research has found that AQP4 deletion in animals reduces cerebral edema after acute ischemic stroke compared with wild type animal models. The mislocalization of astrocytic AQP4 was also presented after ischemic stroke. As the cerebral edema after ischemic stroke is difficult to treat, we discuss several potential treatment targets related to glymphatic system. More studies are needed to explore the role of glymphatic system in the formation of cerebral edema after ischemic stroke and develop probable treatment strategies.
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Affiliation(s)
- Caihong Ji
- Department of Neurology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xing Yu
- Department of Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Weilin Xu
- Department of Neurosurgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Cameron Lenahan
- Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, USA; Burrell College of Osteopathic Medicine, Las Cruces, NM, USA
| | - Sheng Tu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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30
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Benveniste H, Lee H, Ozturk B, Chen X, Koundal S, Vaska P, Tannenbaum A, Volkow ND. Glymphatic Cerebrospinal Fluid and Solute Transport Quantified by MRI and PET Imaging. Neuroscience 2020; 474:63-79. [PMID: 33248153 DOI: 10.1016/j.neuroscience.2020.11.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/04/2020] [Accepted: 11/07/2020] [Indexed: 12/13/2022]
Abstract
Over the past decade there has been an enormous progress in our understanding of fluid and solute transport in the central nervous system (CNS). This is due to a number of factors, including important developments in whole brain imaging technology and computational fluid dynamics analysis employed for the elucidation of glymphatic transport function in the live animal and human brain. In this paper, we review the technical aspects of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in combination with administration of Gd-based tracers into the cerebrospinal fluid (CSF) for tracking glymphatic solute and fluid transport in the CNS as well as lymphatic drainage. Used in conjunction with advanced computational processing methods including optimal mass transport analysis, one gains new insights into the biophysical forces governing solute transport in the CNS which leads to intriguing new research directions. Considering drainage pathways, we review the novel T1 mapping technique for quantifying glymphatic transport and cervical lymph node drainage concurrently in the same subject. We provide an overview of knowledge gleaned from DCE-MRI studies of glymphatic transport and meningeal lymphatic drainage. Finally, we introduce positron emission tomography (PET) and CSF administration of radiotracers as an alternative method to explore other pharmacokinetic aspects of CSF transport into brain parenchyma as well as efflux pathways.
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Affiliation(s)
- Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States; Department of Biomedical Engineering, Yale School of Medicine, New Haven, CT, United States.
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States
| | - Burhan Ozturk
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States
| | - Xinan Chen
- Departments of Computer Science and Applied Mathematics & Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States
| | - Paul Vaska
- Department of Radiology and Biomedical Engineering, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, United States
| | - Allen Tannenbaum
- Departments of Computer Science and Applied Mathematics & Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Nora D Volkow
- Laboratory for Neuroimaging, NIAAA, Bethesda, MD, United States
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