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Che J, Sun Y, Deng Y, Zhang J. Blood-brain barrier disruption: a culprit of cognitive decline? Fluids Barriers CNS 2024; 21:63. [PMID: 39113115 PMCID: PMC11305076 DOI: 10.1186/s12987-024-00563-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 07/31/2024] [Indexed: 08/10/2024] Open
Abstract
Cognitive decline covers a broad spectrum of disorders, not only resulting from brain diseases but also from systemic diseases, which seriously influence the quality of life and life expectancy of patients. As a highly selective anatomical and functional interface between the brain and systemic circulation, the blood-brain barrier (BBB) plays a pivotal role in maintaining brain homeostasis and normal function. The pathogenesis underlying cognitive decline may vary, nevertheless, accumulating evidences support the role of BBB disruption as the most prevalent contributing factor. This may mainly be attributed to inflammation, metabolic dysfunction, cell senescence, oxidative/nitrosative stress and excitotoxicity. However, direct evidence showing that BBB disruption causes cognitive decline is scarce, and interestingly, manipulation of the BBB opening alone may exert beneficial or detrimental neurological effects. A broad overview of the present literature shows a close relationship between BBB disruption and cognitive decline, the risk factors of BBB disruption, as well as the cellular and molecular mechanisms underlying BBB disruption. Additionally, we discussed the possible causes leading to cognitive decline by BBB disruption and potential therapeutic strategies to prevent BBB disruption or enhance BBB repair. This review aims to foster more investigations on early diagnosis, effective therapeutics, and rapid restoration against BBB disruption, which would yield better cognitive outcomes in patients with dysregulated BBB function, although their causative relationship has not yet been completely established.
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Affiliation(s)
- Ji Che
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, No.270 Dong'An Road, Xuhui District, Shanghai, 200032, P. R. China
| | - Yinying Sun
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, No.270 Dong'An Road, Xuhui District, Shanghai, 200032, P. R. China
| | - Yixu Deng
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, No.270 Dong'An Road, Xuhui District, Shanghai, 200032, P. R. China
| | - Jun Zhang
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, No.270 Dong'An Road, Xuhui District, Shanghai, 200032, P. R. China.
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, P. R. China.
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2
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van Hameren G, Aboghazleh R, Parker E, Dreier JP, Kaufer D, Friedman A. From spreading depolarization to blood-brain barrier dysfunction: navigating traumatic brain injury for novel diagnosis and therapy. Nat Rev Neurol 2024; 20:408-425. [PMID: 38886512 DOI: 10.1038/s41582-024-00973-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2024] [Indexed: 06/20/2024]
Abstract
Considerable strides in medical interventions during the acute phase of traumatic brain injury (TBI) have brought improved overall survival rates. However, following TBI, people often face ongoing, persistent and debilitating long-term complications. Here, we review the recent literature to propose possible mechanisms that lead from TBI to long-term complications, focusing particularly on the involvement of a compromised blood-brain barrier (BBB). We discuss evidence for the role of spreading depolarization as a key pathological mechanism associated with microvascular dysfunction and the transformation of astrocytes to an inflammatory phenotype. Finally, we summarize new predictive and diagnostic biomarkers and explore potential therapeutic targets for treating long-term complications of TBI.
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Affiliation(s)
- Gerben van Hameren
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Refat Aboghazleh
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, Al-Salt, Jordan
| | - Ellen Parker
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
- Division of Neurosurgery, Dalhousie University QEII Health Sciences Centre, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - Jens P Dreier
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- Einstein Center for Neurosciences Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Daniela Kaufer
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada.
- Department of Cell Biology, Cognitive and Brain Sciences, Zelman Inter-Disciplinary Center of Brain Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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3
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Aboghazleh R, Boyajian SD, Atiyat A, Udwan M, Al-Helalat M, Al-Rashaideh R. Rodent brain extraction and dissection: A comprehensive approach. MethodsX 2024; 12:102516. [PMID: 38162147 PMCID: PMC10755769 DOI: 10.1016/j.mex.2023.102516] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024] Open
Abstract
The neuroscience is continuously expanding field, and conducting experiments serves as one of the most effective approaches to enhance and broad our understanding of this fascinating field. Most of the lab work in neuroscience involves the use of animal models such as rats and mice for experiments dedicated to monitoring cerebral changes. The study:•Introduces a practical method for brain extraction without perfusion with paraformaldehyde prioritizing brain integrity and avoiding damage.•Offers a detailed, step-by-step dissection guide for different brain regions, including the hippocampus, cerebral cortex, corpus striatum, thalamus, cerebellum, and medial prefrontal cortex, from rodent brains, accompanied by high-resolution images that provide anatomical clarity.•Presents enhanced reliability, precision, and detailed anatomical descriptions.Conclusion: This study has introduced a reliable technique for brain extraction that eliminates the need for paraformaldehyde perfusion. Furthermore, a comprehensive methodology has been presented for extracting different brain regions from rodent brains.
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Affiliation(s)
- Refat Aboghazleh
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, The College of Medicine Building, Al-Salt 19117, Jordan
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Canada
| | - Silvia D. Boyajian
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, The College of Medicine Building, Al-Salt 19117, Jordan
| | - Afnan Atiyat
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, The College of Medicine Building, Al-Salt 19117, Jordan
| | - Manal Udwan
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, The College of Medicine Building, Al-Salt 19117, Jordan
| | - Mimas Al-Helalat
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, The College of Medicine Building, Al-Salt 19117, Jordan
| | - Renad Al-Rashaideh
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, The College of Medicine Building, Al-Salt 19117, Jordan
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4
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Blaschke SJ, Rautenberg N, Endepols H, Jendro A, Konrad J, Vlachakis S, Wiedermann D, Schroeter M, Hoffmann B, Merkel R, Marklund N, Fink GR, Rueger MA. Early Blood-Brain Barrier Impairment as a Pathological Hallmark in a Novel Model of Closed-Head Concussive Brain Injury (CBI) in Mice. Int J Mol Sci 2024; 25:4837. [PMID: 38732053 PMCID: PMC11084321 DOI: 10.3390/ijms25094837] [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: 03/25/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/13/2024] Open
Abstract
Concussion, caused by a rotational acceleration/deceleration injury mild enough to avoid structural brain damage, is insufficiently captured in recent preclinical models, hampering the relation of pathophysiological findings on the cellular level to functional and behavioral deficits. We here describe a novel model of unrestrained, single vs. repetitive concussive brain injury (CBI) in male C56Bl/6j mice. Longitudinal behavioral assessments were conducted for up to seven days afterward, alongside the evaluation of structural cerebral integrity by in vivo magnetic resonance imaging (MRI, 9.4 T), and validated ex vivo by histology. Blood-brain barrier (BBB) integrity was analyzed by means of fluorescent dextran- as well as immunoglobulin G (IgG) extravasation, and neuroinflammatory processes were characterized both in vivo by positron emission tomography (PET) using [18F]DPA-714 and ex vivo using immunohistochemistry. While a single CBI resulted in a defined, subacute neuropsychiatric phenotype, longitudinal cognitive testing revealed a marked decrease in spatial cognition, most pronounced in mice subjected to CBI at high frequency (every 48 h). Functional deficits were correlated to a parallel disruption of the BBB, (R2 = 0.29, p < 0.01), even detectable by a significant increase in hippocampal uptake of [18F]DPA-714, which was not due to activation of microglia, as confirmed immunohistochemically. Featuring a mild but widespread disruption of the BBB without evidence of macroscopic damage, this model induces a characteristic neuro-psychiatric phenotype that correlates to the degree of BBB disruption. Based on these findings, the BBB may function as both a biomarker of CBI severity and as a potential treatment target to improve recovery from concussion.
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Affiliation(s)
- Stefan J. Blaschke
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, 52428 Juelich, Germany
| | - Nora Rautenberg
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, 52428 Juelich, Germany
| | - Heike Endepols
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany;
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
- Nuclear Chemistry, Institute of Neuroscience and Medicine (INM-5), Research Centre Juelich, 52428 Juelich, Germany
| | - Aileen Jendro
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
| | - Jens Konrad
- Mechanobiology, Institute of Biological Information Processing (IBI-2), Research Centre Juelich, 52425 Juelich, Germany; (J.K.); (B.H.); (R.M.)
| | - Susan Vlachakis
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
| | - Dirk Wiedermann
- Multimodal Imaging Group, Max Planck Institute for Metabolism Research, 50931 Cologne, Germany;
| | - Michael Schroeter
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, 52428 Juelich, Germany
| | - Bernd Hoffmann
- Mechanobiology, Institute of Biological Information Processing (IBI-2), Research Centre Juelich, 52425 Juelich, Germany; (J.K.); (B.H.); (R.M.)
| | - Rudolf Merkel
- Mechanobiology, Institute of Biological Information Processing (IBI-2), Research Centre Juelich, 52425 Juelich, Germany; (J.K.); (B.H.); (R.M.)
| | - Niklas Marklund
- Department of Clinical Sciences Lund, Neurosurgery, Lund University, 221 85 Lund, Sweden;
| | - Gereon R. Fink
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, 52428 Juelich, Germany
| | - Maria A. Rueger
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, 50923 Cologne, Germany; (N.R.); (A.J.); (M.S.); (G.R.F.); (M.A.R.)
- Cognitive Neuroscience Section, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, 52428 Juelich, Germany
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5
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Maclean MA, Rogers PS, Muradov JH, Pickett GE, Friedman A, Weeks A, Greene R, Volders D. Contrast-Induced Encephalopathy and the Blood-Brain Barrier. Can J Neurol Sci 2024:1-10. [PMID: 38453685 DOI: 10.1017/cjn.2024.38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
BACKGROUND Contrast-induced encephalopathy (CIE) is an adverse event associated with diagnostic and therapeutic endovascular procedures. Decades of animal and human research support a mechanistic role for pathological blood-brain barrier dysfunction (BBBd). Here, we describe an institutional case series and review the literature supporting a mechanistic role for BBBd in CIE. METHODS A literature review was conducted by searching MEDLINE, Web of Science, Embase, CINAHL and Cochrane databases from inception to January 31, 2022. We searched our institutional neurovascular database for cases of CIE following endovascular treatment of cerebrovascular disease during a 6-month period. Informed consent was obtained in all cases. RESULTS Review of the literature revealed risk factors for BBBd and CIE, including microvascular disease, pathological neuroinflammation, severe procedural hypertension, iodinated contrast load and altered cerebral blood flow dynamics. In our institutional series, 6 of 52 (11.5%) of patients undergoing therapeutic neuroendovascular procedures developed CIE during the study period. Four patients were treated for ischemic stroke and two patients for recurrent cerebral aneurysms. Mechanical stenting or thrombectomy were utilized in all cases. CONCLUSION In this institutional case series and literature review of animal and human data, we identified numerous shared risk factors for CIE and BBBd, including microvascular disease, increased procedure length, large contrast volumes, severe intraoperative hypertension and use of mechanical devices that may induce iatrogenic endothelial injury.
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Affiliation(s)
- Mark A Maclean
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | - Patrick S Rogers
- Department of Diagnostic Radiology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Jamil H Muradov
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Gwynedd E Pickett
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Adrienne Weeks
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | - Ryan Greene
- Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada
| | - David Volders
- Department of Diagnostic Radiology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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6
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Liraz Zaltsman S, Sharabi S, Guez D, Daniels D, Cooper I, Shemesh C, Atrakchi D, Ravid O, Omesi L, Rand D, Livny A, Schnaider Beeri M, Friedman-Levi Y, Shohami E, Mardor Y, Last D. Application of Delayed Contrast Extravasation Magnetic Resonance Imaging for Depicting Subtle Blood-Brain Barrier Disruption in a Traumatic Brain Injury Model. J Neurotrauma 2024; 41:430-446. [PMID: 37776183 DOI: 10.1089/neu.2023.0048] [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] [Indexed: 10/01/2023] Open
Abstract
The blood-brain barrier (BBB) is composed of brain microvasculature that provides selective transport of solutes from the systemic circulation into the central nervous system to protect the brain and spinal microenvironment. Damage to the BBB in the acute phase after traumatic brain injury (TBI) is recognized as a major underlying mechanism leading to secondary long-term damage. Because of the lack of technological ability to detect subtle BBB disruption (BBBd) in the chronic phase, however, the presence of chronic BBBd is disputable. Thus, the dynamics and course of long-term BBBd post-TBI remains elusive. Thirty C57BL/6 male mice subjected to TBI using our weight drop closed head injury model and 19 naïve controls were scanned by magnetic resonance imaging (MRI) up to 540 days after injury. The BBB maps were calculated from delayed contrast extravasation MRI (DCM) with high spatial resolution and high sensitivity to subtle BBBd, enabling depiction and quantification of BBB permeability. At each time point, 2-6 animals were sacrificed and their brains were extracted, sectioned, and stained for BBB biomarkers including: blood microvessel coverage by astrocyte using GFAP, AQP4, ZO-1 gaps, and IgG leakage. We found that DCM provided depiction of subtle yet significant BBBd up to 1.5 years after TBI, with significantly higher sensitivity than standard contrast-enhanced T1-weighted and T2-weighted MRI (BBBd volumes main effect DCM/T1/T2 p < 0.0001 F(2,70) = 107.3, time point p < 0.0001 F(2,133, 18.66) = 23.53). In 33% of the cases, both in the acute and chronic stages, there was no detectable enhancement on standard T1-MRI, nor detectable hyperintensities on T2-MRI, whereas DCM showed significant BBBd volumes. The BBBd values of TBI mice at the chronic stage were found significantly higher compared with age matched naïve animals at 30, 60, and 540 days. The calculated BBB maps were histologically validated by determining significant correlation between the calculated levels of disruption and a diverse set of histopathological parameters obtained from different brain regions, presenting different components of the BBB. Cumulative evidence from recent years points to BBBd as a central component of the pathophysiology of TBI. Therefore, it is expected that routine use of highly sensitive non-invasive techniques to measure BBBd, such as DCM with advanced analysis methods, may enhance our understanding of the changes in BBB function after TBI. Application of the DCM technology to other CNS disorders, as well as to normal aging, may shed light on the involvement of chronic subtle BBBd in these conditions.
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Affiliation(s)
- Sigal Liraz Zaltsman
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
- Department of Pharmacology, Institute for Drug Research, The Hebrew University, Jerusalem, Israel
- Institutes for Health and Medical Professions, Department of Sports Therapy, Ono Academic College, Kiryat Ono, Israel
| | - Shirley Sharabi
- The Advanced Technology Center, Sheba Medical Center, Tel Hashomer, Israel
| | - David Guez
- The Advanced Technology Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Diann Daniels
- The Advanced Technology Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Itzik Cooper
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
- School of Psychology, Reichman University (IDC), Herzliya, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chen Shemesh
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Dana Atrakchi
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Orly Ravid
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Liora Omesi
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Daniel Rand
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Abigail Livny
- Departments of Diagnostic Imaging and Psychiatry, Sheba Medical Center, Ramat Gan, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Israel
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
- Department of Psychiatry, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Yael Friedman-Levi
- Department of Pharmacology, Institute for Drug Research, The Hebrew University, Jerusalem, Israel
| | - Esther Shohami
- Department of Pharmacology, Institute for Drug Research, The Hebrew University, Jerusalem, Israel
| | - Yael Mardor
- The Advanced Technology Center, Sheba Medical Center, Tel Hashomer, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - David Last
- The Advanced Technology Center, Sheba Medical Center, Tel Hashomer, Israel
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7
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Pinkowski NJ, Fish B, Mehos CJ, Carlson VL, Hess BR, Mayer AR, Morton RA. Spreading Depolarizations Contribute to the Acute Behavior Deficits Associated With a Mild Traumatic Brain Injury in Mice. J Neurotrauma 2024; 41:271-291. [PMID: 37742105 PMCID: PMC11071091 DOI: 10.1089/neu.2023.0152] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/25/2023] Open
Abstract
Concussions or mild traumatic brain injuries (mTBIs) are often described and diagnosed by the acute signs and symptoms of neurological dysfunction including weakness, dizziness, disorientation, headaches, and altered mental state. The cellular and physiological mechanisms of neurological dysfunction and acute symptoms are unclear. Spreading depolarizations (SDs) occur after severe TBIs and have recently been identified in closed-skull mouse models of mTBIs. SDs are massive waves of complete depolarization that result in suppression of cortical activity for multiple minutes. Despite the clear disruption of brain physiology after SDs, the role of SDs in the acute neurological dysfunction and acute behavioral deficits following mTBIs remains unclear. We used a closed-skull mouse model of mTBI and a series of behavioral tasks collectively scored as the neurological severity score (NSS) to assess acute behavior. Our results indicate that mTBIs are associated with significant behavioral deficits in the open field and NSS tasks relative to sham-condition animals. The behavioral deficits associated with the mTBI recovered within 3 h. We show here that the presence of mTBI-induced bilateral SDs were significantly associated with the acute behavioral deficits. To identify the role of SDs in the acute behavioral deficits, we used exogenous potassium and optogenetic approaches to induce SDs in the absence of the mTBI. Bilateral SDs alone were associated with similar behavioral deficits in the open field and NSS tasks. Collectively, these studies demonstrate that bilateral SDs are linked to the acute behavioral deficits associated with mTBIs.
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Affiliation(s)
- Natalie J Pinkowski
- Department of Neurosciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Center for Brain Recovery and Repair, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Betty Fish
- Department of Neurosciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Center for Brain Recovery and Repair, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Carissa J Mehos
- Department of Neurosciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Center for Brain Recovery and Repair, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Victoria L Carlson
- Department of Neurosciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
| | - Brandi R Hess
- Department of Neurosciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Center for Brain Recovery and Repair, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Andrew R Mayer
- Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico, USA
- Department of Neurology, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Department of Psychiatry and Behavioral Sciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Department of Psychology, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
| | - Russell A Morton
- Department of Neurosciences, University of New Mexico, School of Medicine, Albuquerque, New Mexico, USA
- Center for Brain Recovery and Repair, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
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8
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MacLean MA, Muradov JH, Greene R, Van Hameren G, Clarke DB, Dreier JP, Okonkwo DO, Friedman A. Memantine inhibits cortical spreading depolarization and improves neurovascular function following repetitive traumatic brain injury. SCIENCE ADVANCES 2023; 9:eadj2417. [PMID: 38091390 PMCID: PMC10848720 DOI: 10.1126/sciadv.adj2417] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 11/14/2023] [Indexed: 12/18/2023]
Abstract
Cortical spreading depolarization (CSD) is a promising target for neuroprotective therapy in traumatic brain injury (TBI). We explored the effect of NMDA receptor antagonism on electrically triggered CSDs in healthy and brain-injured animals. Rats received either one moderate or four daily repetitive mild closed head impacts (rmTBI). Ninety-three animals underwent craniectomy with electrocorticographic (ECoG) and local blood flow monitoring. In brain-injured animals, ketamine or memantine inhibited CSDs in 44 to 88% and 50 to 67% of cases, respectively. Near-DC/AC-ECoG amplitude was reduced by 44 to 75% and 52 to 67%, and duration by 39 to 87% and 61 to 78%, respectively. Daily memantine significantly reduced spreading depression and oligemia following CSD. Animals (N = 31) were randomized to either memantine (10 mg/kg) or saline with daily neurobehavioral testing. Memantine-treated animals had higher neurological scores. We demonstrate that memantine improved neurovascular function following CSD in sham and brain-injured animals. Memantine also prevented neurological decline in a blinded, preclinical randomized rmTBI trial.
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Affiliation(s)
- Mark A. MacLean
- Division of Neurosurgery, Dalhousie University, Halifax, Canada
| | - Jamil H. Muradov
- Department of Medical Neuroscience, Dalhousie University, Halifax, Canada
| | - Ryan Greene
- Department of Medical Neuroscience, Dalhousie University, Halifax, Canada
| | - Gerben Van Hameren
- Department of Medical Neuroscience, Dalhousie University, Halifax, Canada
| | - David B. Clarke
- Division of Neurosurgery, Dalhousie University, Halifax, Canada
| | - Jens P. Dreier
- Center for Stroke Research Berlin, Charite University, Berlin, Germany
| | - David O. Okonkwo
- Division of Neurosurgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alon Friedman
- Division of Neurosurgery, Dalhousie University, Halifax, Canada
- Department of Medical Neuroscience, Dalhousie University, Halifax, Canada
- Departments of Brain and Cognitive Sciences, Physiology and Cell Biology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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9
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van Hameren G, Muradov J, Minarik A, Aboghazleh R, Orr S, Cort S, Andrews K, McKenna C, Pham NT, MacLean MA, Friedman A. Mitochondrial dysfunction underlies impaired neurovascular coupling following traumatic brain injury. Neurobiol Dis 2023; 186:106269. [PMID: 37619791 DOI: 10.1016/j.nbd.2023.106269] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 08/26/2023] Open
Abstract
Traumatic brain injury (TBI) involves an acute injury (primary damage), which may evolve in the hours to days after impact (secondary damage). Seizures and cortical spreading depolarization (CSD) are metabolically demanding processes that may worsen secondary brain injury. Metabolic stress has been associated with mitochondrial dysfunction, including impaired calcium homeostasis, reduced ATP production, and elevated ROS production. However, the association between mitochondrial impairment and vascular function after TBI is poorly understood. Here, we explored this association using a rodent closed head injury model. CSD is associated with neurobehavioral decline after TBI. Craniotomy was performed to elicit CSD via electrical stimulation or to induce seizures via 4-aminopyridine application. We measured vascular dysfunction following CSDs and seizures in TBI animals using laser doppler flowmetry. We observed a more profound reduction in local cortical blood flow in TBI animals compared to healthy controls. CSD resulted in mitochondrial dysfunction and pathological signs of increased oxidative stress adjacent to the vasculature. We explored these findings further using electron microscopy and found that TBI and CSDs resulted in vascular morphological changes and mitochondrial cristae damage in astrocytes, pericytes and endothelial cells. Overall, we provide evidence that CSDs induce mitochondrial dysfunction, impaired cortical blood flow, and neurobehavioral deficits in the setting of TBI.
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Affiliation(s)
- Gerben van Hameren
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada.
| | - Jamil Muradov
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Anna Minarik
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Refat Aboghazleh
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada; Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, Al-Salt, Jordan
| | - Sophie Orr
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Shayna Cort
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Keiran Andrews
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Caitlin McKenna
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Nga Thy Pham
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada
| | - Mark A MacLean
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada; Division of Neurosurgery, Department of Surgery, Dalhousie University, NS B3H 3A7, Halifax, Canada
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, NS B3H 4H7, Halifax, Canada; Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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10
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Schoknecht K, Hirrlinger J, Eilers J. Transient astrocytic accumulation of fluorescein during spreading depolarizations. Neurobiol Dis 2023; 178:106026. [PMID: 36731681 DOI: 10.1016/j.nbd.2023.106026] [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: 08/23/2022] [Revised: 01/16/2023] [Accepted: 01/29/2023] [Indexed: 02/01/2023] Open
Abstract
Spreading depolarizations (SDs) occur frequently in acute cerebral injuries. They are characterized by a breakdown of transmembrane ion gradients resulting in a reduced extracellular sodium ([Na+]o) and increased extracellular potassium concentration ([K+]o). Elevated [K+]o induces astrocytic swelling, another feature of SD; however, the solutes that drive astrocytic swelling remain incompletely understood. We incidentally found astrocytic accumulation of fluorescein (Fluo) - a low molecular weight anionic dye - during SDs induced by elevated [K+]o. Herein, we aimed to explore the properties of astrocytic Fluo accumulation during SDs, electrical stimulation, [K+]o and glutamate elevation and elucidate underlying mechanisms and its relation to swelling. Experiments were performed in acute neocortical slices from adult male C57Bl6 mice and transgenic mice expressing tdTomato in parvalbumin (PV)-positive neurons. We labeled astrocytes with sulforhodamine-101 (SR-101), measured Fluo kinetics using 2-photon laser scanning microscopy and recorded local field potentials (LFP) to detect SDs. Elevations of [K+]o lead to an increase of the astrocytic Fluo intensity in parallel with astrocytic swelling. Pharmacological inhibitors of sodium‑potassium ATPase (Na/K-ATPase), secondary-active transporters and channels were used to address the underlying mechanisms. Fluo accumulation as well as swelling were only prevented by inhibition of the sodium‑potassium ATPase. Application of glutamate or hypoosmolar solution induced astrocytic swelling independent of Fluo accumulation and glutamate opposed Fluo accumulation when co-administered with high [K+]o. Astrocytes accumulated Fluo and swelled during electrical stimulation and even more during SDs. Taken together, Fluo imaging can be used as a tool to visualize yet unidentified anion fluxes during [K+]o- but not glutamate- or hypoosmolarity induced astrocytic swelling. Fluo imaging may thereby help to elucidate mechanisms of astrocytic swelling and associated fluid movements between brain compartments during physiological and pathological conditions, e.g. SDs.
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Affiliation(s)
- Karl Schoknecht
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany.
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany; Department of Neurogenetics, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Jens Eilers
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany
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11
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Preininger MK, Kaufer D. Blood-Brain Barrier Dysfunction and Astrocyte Senescence as Reciprocal Drivers of Neuropathology in Aging. Int J Mol Sci 2022; 23:6217. [PMID: 35682895 PMCID: PMC9180977 DOI: 10.3390/ijms23116217] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/26/2022] [Accepted: 05/29/2022] [Indexed: 01/27/2023] Open
Abstract
As the most abundant cell types in the brain, astrocytes form a tissue-wide signaling network that is responsible for maintaining brain homeostasis and regulating various brain activities. Here, we review some of the essential functions that astrocytes perform in supporting neurons, modulating the immune response, and regulating and maintaining the blood-brain barrier (BBB). Given their importance in brain health, it follows that astrocyte dysfunction has detrimental effects. Indeed, dysfunctional astrocytes are implicated in age-related neuropathology and participate in the onset and progression of neurodegenerative diseases. Here, we review two mechanisms by which astrocytes mediate neuropathology in the aging brain. First, age-associated blood-brain barrier dysfunction (BBBD) causes the hyperactivation of TGFβ signaling in astrocytes, which elicits a pro-inflammatory and epileptogenic phenotype. Over time, BBBD-associated astrocyte dysfunction results in hippocampal and cortical neural hyperexcitability and cognitive deficits. Second, senescent astrocytes accumulate in the brain with age and exhibit a decreased functional capacity and the secretion of senescent-associated secretory phenotype (SASP) factors, which contribute to neuroinflammation and neurotoxicity. Both BBBD and senescence progressively increase during aging and are associated with increased risk of neurodegenerative disease, but the relationship between the two has not yet been established. Thus, we discuss the potential relationship between BBBD, TGFβ hyperactivation, and senescence with respect to astrocytes in the context of aging and disease and identify future areas of investigation in the field.
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Affiliation(s)
- Marcela K. Preininger
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA;
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Daniela Kaufer
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA;
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
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