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Remodeling of the Neurovascular Unit Following Cerebral Ischemia and Hemorrhage. Cells 2022; 11:cells11182823. [PMID: 36139398 PMCID: PMC9496956 DOI: 10.3390/cells11182823] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/18/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
Formulated as a group effort of the stroke community, the transforming concept of the neurovascular unit (NVU) depicts the structural and functional relationship between brain cells and the vascular structure. Composed of both neural and vascular elements, the NVU forms the blood-brain barrier that regulates cerebral blood flow to meet the oxygen demand of the brain in normal physiology and maintain brain homeostasis. Conversely, the dysregulation and dysfunction of the NVU is an essential pathological feature that underlies neurological disorders spanning from chronic neurodegeneration to acute cerebrovascular events such as ischemic stroke and cerebral hemorrhage, which were the focus of this review. We also discussed how common vascular risk factors of stroke predispose the NVU to pathological changes. We synthesized existing literature and first provided an overview of the basic structure and function of NVU, followed by knowledge of how these components remodel in response to ischemic stroke and brain hemorrhage. A greater understanding of the NVU dysfunction and remodeling will enable the design of targeted therapies and provide a valuable foundation for relevant research in this area.
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2
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Ghaddar B, Diotel N. Zebrafish: A New Promise to Study the Impact of Metabolic Disorders on the Brain. Int J Mol Sci 2022; 23:ijms23105372. [PMID: 35628176 PMCID: PMC9141892 DOI: 10.3390/ijms23105372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/04/2022] [Accepted: 05/06/2022] [Indexed: 02/01/2023] Open
Abstract
Zebrafish has become a popular model to study many physiological and pathophysiological processes in humans. In recent years, it has rapidly emerged in the study of metabolic disorders, namely, obesity and diabetes, as the regulatory mechanisms and metabolic pathways of glucose and lipid homeostasis are highly conserved between fish and mammals. Zebrafish is also widely used in the field of neurosciences to study brain plasticity and regenerative mechanisms due to the high maintenance and activity of neural stem cells during adulthood. Recently, a large body of evidence has established that metabolic disorders can alter brain homeostasis, leading to neuro-inflammation and oxidative stress and causing decreased neurogenesis. To date, these pathological metabolic conditions are also risk factors for the development of cognitive dysfunctions and neurodegenerative diseases. In this review, we first aim to describe the main metabolic models established in zebrafish to demonstrate their similarities with their respective mammalian/human counterparts. Then, in the second part, we report the impact of metabolic disorders (obesity and diabetes) on brain homeostasis with a particular focus on the blood-brain barrier, neuro-inflammation, oxidative stress, cognitive functions and brain plasticity. Finally, we propose interesting signaling pathways and regulatory mechanisms to be explored in order to better understand how metabolic disorders can negatively impact neural stem cell activity.
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3
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Liu Y, Chen D, Smith A, Ye Q, Gao Y, Zhang W. Three-dimensional remodeling of functional cerebrovascular architecture and gliovascular unit in leptin receptor-deficient mice. J Cereb Blood Flow Metab 2021; 41:1547-1562. [PMID: 33818188 PMCID: PMC8221780 DOI: 10.1177/0271678x211006596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 12/17/2022]
Abstract
The cerebrovascular sequelae of diabetes render victims more susceptible to ischemic stroke, vascular cognitive impairment, and Alzheimer's disease. However, limited knowledge exists on the progressive changes in cerebrovascular structure and functional remodeling in type 2 diabetes. To ascertain the impact of diabetes on whole-brain cerebrovascular perfusion, leptin-receptor-deficient mice were transcardially injected with tomato-lectin before sacrifice. The whole brain was clarified by the Fast free-of-acrylamide clearing tissue technique. Functional vascular anatomy of the cerebrum was visualized by light-sheet microscopy, followed by analysis in Imaris software. We observed enhanced neovascularization in adult db/db mice, characterized by increased branch level and loop structures. Microvascular hypoperfusion was initially detected in juvenile db/db mice, suggesting early onset of insufficient microcirculation. Furthermore, gliovascular unit remodeling was verified by loss of pericytes and overactivation of microglia and astrocytes in adult diabetic mice. However, the integrity of the blood-brain barrier (BBB) was fundamentally preserved, as shown by a lack of extravasation of IgG into the brain parenchyma. In summary, we, for the first time, reveal that functional cerebrovascular remodeling occurs as early as four weeks in db/db mice and the deficit in gliovascular coupling may play a role in cerebral hypoperfusion before BBB breakdown in 16-week-old db/db mice.
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Affiliation(s)
- Yaan Liu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Di Chen
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Amanda Smith
- Department of Neurology, Pittsburgh Institute of Brain Disorders & Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Qing Ye
- Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Wenting Zhang
- Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, USA
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4
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Banks WA. The Blood-Brain Barrier Interface in Diabetes Mellitus: Dysfunctions, Mechanisms and Approaches to Treatment. Curr Pharm Des 2020; 26:1438-1447. [DOI: 10.2174/1381612826666200325110014] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/27/2020] [Indexed: 12/24/2022]
Abstract
Diabetes mellitus (DM) is one of the most common diseases in the world. Among its effects are an increase in the risk of cognitive impairment, including Alzheimer’s disease, and blood-brain barrier (BBB) dysfunction. DM is characterized by high blood glucose levels that are caused by either lack of insulin (Type I) or resistance to the actions of insulin (Type II). The phenotypes of these two types are dramatically different, with Type I animals being thin, with low levels of leptin as well as insulin, whereas Type II animals are often obese with high levels of both leptin and insulin. The best characterized change in BBB dysfunction is that of disruption. The brain regions that are disrupted, however, vary between Type I vs Type II DM, suggesting that factors other than hyperglycemia, perhaps hormonal factors such as leptin and insulin, play a regionally diverse role in BBB vulnerability or protection. Some BBB transporters are also altered in DM, including P-glycoprotein, lowdensity lipoprotein receptor-related protein 1, and the insulin transporter as other functions of the BBB, such as brain endothelial cell (BEC) expression of matrix metalloproteinases (MMPs) and immune cell trafficking. Pericyte loss secondary to the increased oxidative stress of processing excess glucose through the Krebs cycle is one mechanism that has shown to result in BBB disruption. Vascular endothelial growth factor (VEGF) induced by advanced glycation endproducts can increase the production of matrix metalloproteinases, which in turn affects tight junction proteins, providing another mechanism for BBB disruption as well as effects on P-glycoprotein. Through the enhanced expression of the redox-related mitochondrial transporter ABCB10, redox-sensitive transcription factor NF-E2 related factor-2 (Nrf2) inhibits BEC-monocyte adhesion. Several potential therapies, in addition to those of restoring euglycemia, can prevent some aspects of BBB dysfunction. Carbonic anhydrase inhibition decreases glucose metabolism and so reduces oxidative stress, preserving pericytes and blocking or reversing BBB disruption. Statins or N-acetylcysteine can reverse the BBB opening in some models of DM, fibroblast growth factor-21 improves BBB permeability through an Nrf2-dependent pathway, and nifedipine or VEGF improves memory in DM models. In summary, DM alters various aspects of BBB function through a number of mechanisms. A variety of treatments based on those mechanisms, as well as restoration of euglycemia, may be able to restore BBB functions., including reversal of BBB disruption.
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Affiliation(s)
- William A. Banks
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, United States
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5
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Calderón-Garcidueñas L, Mukherjee PS, Waniek K, Holzer M, Chao CK, Thompson C, Ruiz-Ramos R, Calderón-Garcidueñas A, Franco-Lira M, Reynoso-Robles R, Gónzalez-Maciel A, Lachmann I. Non-Phosphorylated Tau in Cerebrospinal Fluid is a Marker of Alzheimer's Disease Continuum in Young Urbanites Exposed to Air Pollution. J Alzheimers Dis 2019; 66:1437-1451. [PMID: 30412505 DOI: 10.3233/jad-180853] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Long-term exposure to fine particulate matter (PM2.5) and ozone (O3) above USEPA standards is associated with Alzheimer's disease (AD) risk. Metropolitan Mexico City (MMC) children exhibit subcortical pretangles in infancy and cortical tau pre-tangles, NFTs, and amyloid phases 1-2 by the 2nd decade. Given their AD continuum, we measured in 507 normal cerebrospinal fluid (CSF) samples (MMC 354, controls 153, 12.82±6.73 y), a high affinity monoclonal non-phosphorylated tau antibody (non-P-Tau), as a potential biomarker of AD and axonal damage. In 81 samples, we also measured total tau (T-Tau), tau phosphorylated at threonine 181 (P-Tau), amyloid-β1-42, BDNF, and vitamin D. We documented by electron microscopy myelinated axonal size and the pathology associated with combustion-derived nanoparticles (CDNPs) in anterior cingulate cortex white matter in 6 young residents (16.25±3.34 y). Non-P-Tau showed a strong increase with age significantly faster among MMC versus controls (p = 0.0055). Aβ1 - 42 and BDNF concentrations were lower in MMC children (p = 0.002 and 0.03, respectively). Anterior cingulate cortex showed a significant decrease (p = <0.0001) in the average axonal size and CDNPs were associated with organelle pathology. Significant age increases in non-P-Tau support tau changes early in a population with axonal pathology and evolving AD hallmarks in the first two decades of life. Non-P-Tau is an early biomarker of axonal damage and potentially valuable to monitor progressive longitudinal changes along with AD multianalyte classical CSF markers. Neuroprotection of young urbanites with PM2.5 and CDNPs exposures ought to be a public health priority to halt the development of AD in the first two decades of life.
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Affiliation(s)
| | | | | | - Max Holzer
- Paul-Flechsig-Institute for Brain Research, Leipzig, Germany
| | | | | | - Rubén Ruiz-Ramos
- Instituto de Medicina Forense, Universidad Veracruzana, Boca del Rio, Mexico
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Disturbance of Intracerebral Fluid Clearance and Blood-Brain Barrier in Vascular Cognitive Impairment. Int J Mol Sci 2019; 20:ijms20102600. [PMID: 31137875 PMCID: PMC6566824 DOI: 10.3390/ijms20102600] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/22/2019] [Accepted: 05/22/2019] [Indexed: 12/18/2022] Open
Abstract
The entry of blood-borne macromolecular substances into the brain parenchyma from cerebral vessels is blocked by the blood–brain barrier (BBB) function. Accordingly, increased permeability of the vessels induced by insult noted in patients suffering from vascular dementia likely contributes to the cognitive impairment. On the other hand, blood-borne substances can enter extracellular spaces of the brain via endothelial cells at specific sites without the BBB, and can move to brain parenchyma, such as the hippocampus and periventricular areas, adjacent to specific sites, indicating the contribution of increased permeability of vessels in the specific sites to brain function. It is necessary to consider influx and efflux of interstitial fluid (ISF) and cerebrospinal fluid (CSF) in considering effects of brain transfer of intravascular substances on brain function. Two pathways of ISF and CSF are recently being established. One is the intramural peri-arterial drainage (IPAD) pathway of ISF. The other is the glymphatic system of CSF. Dysfunction of the two pathways could also contribute to brain dysfunction. We review the effects of several kinds of insult on vascular permeability and the failure of fluid clearance on the brain function.
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7
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Zhao Q, Zhang F, Yu Z, Guo S, Liu N, Jiang Y, Lo EH, Xu Y, Wang X. HDAC3 inhibition prevents blood-brain barrier permeability through Nrf2 activation in type 2 diabetes male mice. J Neuroinflammation 2019; 16:103. [PMID: 31101061 PMCID: PMC6525453 DOI: 10.1186/s12974-019-1495-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/30/2019] [Indexed: 12/19/2022] Open
Abstract
Background Type 2 diabetes mellitus (T2DM) is a chronic metabolic dysfunction characterized by progressive insulin resistance and hyperglycaemia. Increased blood-brain barrier (BBB) permeability is a critical neurovascular complication of T2DM that adversely affects the central nervous system homeostasis and function. Histone deacetylase 3 (HDAC3) has been reported to be elevated in T2DM animals and may promote neuroinflammation; however, its involvement in the BBB permeability of T2DM has not been investigated. In this study, we tested our hypothesis that HDAC3 expression and activity are increased in the T2DM mouse brain. Inhibition of HDAC3 may ameliorate T2DM-induced BBB permeability through Nrf2 activation. Methods T2DM (db/db, leptin receptor-deficient), genetic non-hyperglycemic control (db/+), and wild-type male mice at the age of 16 weeks were used in this study. HDAC3 expression and activity, Nrf2 activation, and BBB permeability and junction protein expression were examined. The effects of HDAC3 activity on BBB permeability were tested using highly selective HDAC3 inhibitor RGFP966. In primary cultured human brain microvascular endothelial cells (HBMEC), hyperglycemia (25 mM glucose) plus interleukin 1 beta (20 ng/ml) (HG-IL1β) served as T2DM insult in vitro. The effects of HDAC3 on transendothelial permeability were investigated by FITC-Dextran leakage and trans-endothelial electrical resistance, and the underlying molecular mechanisms were investigated using Western blot, q-PCR, co-immunoprecipitation, and immunocytochemistry for junction protein expression, miR-200a/Keap1/Nrf2 pathway regulation. Results HDAC3 expression and activity were significantly increased in the hippocampus and cortex of db/db mice. Specific HDAC3 inhibition significantly ameliorated BBB permeability and junction protein downregulation in db/db mice. In cultured HBMEC, HG-IL1β insult significantly increased transendothelial permeability and reduced junction protein expression. HDAC3 inhibition significantly attenuated the transendothelial permeability and junction protein downregulation. Moreover, we demonstrated the underlying mechanism was at least in part attributed by HDAC3 inhibition-mediated miR-200a/Keap1/Nrf2 signaling pathway and downstream targeting junction protein expression in T2DM db/db mice. Conclusions Our experimental results show that HDAC3 might be a new therapeutic target for BBB damage in T2DM. Electronic supplementary material The online version of this article (10.1186/s12974-019-1495-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qiuchen Zhao
- Department of Neurology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, Jiangsu, China.,Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA
| | - Fang Zhang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.,Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA
| | - Zhanyang Yu
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA
| | - Shuzhen Guo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA
| | - Ning Liu
- Department of Neurology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, Jiangsu, China.,The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China
| | - Yinghua Jiang
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA
| | - Yun Xu
- Department of Neurology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, 321 Zhongshan Rd, Nanjing, 210008, Jiangsu, China.
| | - Xiaoying Wang
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Room 2401, Charlestown, Boston, MA, 02129, USA.
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8
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Kanzaki A, Tada H, Otsuka A, Nakamura T. Severe tardive dyskinesia induced by domperidone in presenile and non-dementia type 2 diabetes man with alcohol misuse showing albuminocytological dissociation and white matter hyperintensity. BMJ Case Rep 2019; 12:12/5/e228789. [DOI: 10.1136/bcr-2018-228789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Domperidone has difficulty passing the blood–brain barrier, thus rarely causes tardive dyskinesia. Furthermore, its symptoms in adults are generally mild. Although both alcohol and diabetes are thought to increase the risk of development of tardive dyskinesia, their impact remains controversial, especially diabetes, and factors related to worsened tardive dyskinesia have not been clearly elucidated. A 59-year-old man with type 2 diabetes and history of alcohol misuse, who had been chronically prescribed domperidone at 15 mg/day, showed severe tardive dyskinesia, which was remitted within several days by stopping the drug. In our case, albuminocytological dissociation and white matter hyperintensity on MRI were confirmed, which were thought to be related to blood–brain barrier dysfunction. This present findings indicate that alcohol misuse and type 2 diabetes, as well as albuminocytological dissociation and white matter hyperintensity may result in severe tardive dyskinesia, even in individuals receiving domperidone.
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9
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Erickson MA, Banks WA. Age-Associated Changes in the Immune System and Blood⁻Brain Barrier Functions. Int J Mol Sci 2019; 20:ijms20071632. [PMID: 30986918 PMCID: PMC6479894 DOI: 10.3390/ijms20071632] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 03/26/2019] [Accepted: 03/29/2019] [Indexed: 12/11/2022] Open
Abstract
Age is associated with altered immune functions that may affect the brain. Brain barriers, including the blood-brain barrier (BBB) and blood-CSF barrier (BCSFB), are important interfaces for neuroimmune communication, and are affected by aging. In this review, we explore novel mechanisms by which the aging immune system alters central nervous system functions and neuroimmune responses, with a focus on brain barriers. Specific emphasis will be on recent works that have identified novel mechanisms by which BBB/BCSFB functions change with age, interactions of the BBB with age-associated immune factors, and contributions of the BBB to age-associated neurological disorders. Understanding how age alters BBB functions and responses to pathological insults could provide important insight on the role of the BBB in the progression of cognitive decline and neurodegenerative disease.
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Affiliation(s)
- Michelle A Erickson
- VA Puget Sound Healthcare System, Geriatric Research Education and Clinical Center, Seattle, WA 98108, USA.
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA.
| | - William A Banks
- VA Puget Sound Healthcare System, Geriatric Research Education and Clinical Center, Seattle, WA 98108, USA.
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA.
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10
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Corem N, Anzi S, Gelb S, Ben-Zvi A. Leptin receptor deficiency induces early, transient and hyperglycaemia-independent blood-brain barrier dysfunction. Sci Rep 2019; 9:2884. [PMID: 30814586 PMCID: PMC6393679 DOI: 10.1038/s41598-019-39230-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/18/2019] [Indexed: 12/15/2022] Open
Abstract
Diabetes mellitus (DM) significantly increases susceptibility to central nervous system (CNS) pathologies, including stroke, vascular dementia, cognitive deficits and Alzheimer’s disease. Previous studies (mostly using the streptozotocin model) suggested that blood-brain barrier (BBB) disruption is involved in these conditions. Here, we examined the integrity of brain capillaries and BBB permeability in Leprdb/db obesity-related diabetic mice. Surprisingly, significant BBB leakage was observed only in young mice at the pre-hyperglycemic stage. Thorough examination of barrier permeability at later diabetic stages showed no evidence for significant BBB leakage during the hyperglycemic state. Electron microscopy imaging of mice with short-term hyperglycaemia supported normal BBB permeability but indicated other stress-related changes in capillary ultrastructure, such as mitochondrial degeneration. Based on our study with this mouse genetic model of obesity-related DM, we suggest that previously reported hyperglycaemia-induced BBB leakage is most likely not the underlying mechanism of DM-related CNS pathologies. Finally we propose that BBB hyper-permeability might be an early and transient phenomenon while stress-related endothelial pathologies do correlate with a short-term diabetic state.
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Affiliation(s)
- Noa Corem
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Shira Anzi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Sivan Gelb
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Ayal Ben-Zvi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, 91120, Israel.
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11
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Van Dyken P, Lacoste B. Impact of Metabolic Syndrome on Neuroinflammation and the Blood-Brain Barrier. Front Neurosci 2018; 12:930. [PMID: 30618559 PMCID: PMC6297847 DOI: 10.3389/fnins.2018.00930] [Citation(s) in RCA: 191] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/27/2018] [Indexed: 12/29/2022] Open
Abstract
Metabolic syndrome, which includes diabetes and obesity, is one of the most widespread medical conditions. It induces systemic inflammation, causing far reaching effects on the body that are still being uncovered. Neuropathologies triggered by metabolic syndrome often result from increased permeability of the blood-brain-barrier (BBB). The BBB, a system designed to restrict entry of toxins, immune cells, and pathogens to the brain, is vital for proper neuronal function. Local and systemic inflammation induced by obesity or type 2 diabetes mellitus can cause BBB breakdown, decreased removal of waste, and increased infiltration of immune cells. This leads to disruption of glial and neuronal cells, causing hormonal dysregulation, increased immune sensitivity, or cognitive impairment depending on the affected brain region. Inflammatory effects of metabolic syndrome have been linked to neurodegenerative diseases. In this review, we discuss the effects of obesity and diabetes-induced inflammation on the BBB, the roles played by leptin and insulin resistance, as well as BBB changes occurring at the molecular level. We explore signaling pathways including VEGF, HIFs, PKC, Rho/ROCK, eNOS, and miRNAs. Finally, we discuss the broader implications of neural inflammation, including its connection to Alzheimer's disease, multiple sclerosis, and the gut microbiome.
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Affiliation(s)
- Peter Van Dyken
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Baptiste Lacoste
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
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12
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Charpentier J, Waget A, Klopp P, Magnan C, Cruciani-Guglielmacci C, Lee SJ, Burcelin R, Grasset E. Lixisenatide requires a functional gut-vagus nerve-brain axis to trigger insulin secretion in controls and type 2 diabetic mice. Am J Physiol Gastrointest Liver Physiol 2018; 315:G671-G684. [PMID: 30070580 DOI: 10.1152/ajpgi.00348.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Endogenous glucagon-like peptide-1 (GLP-1) regulates glucose-induced insulin secretion through both direct β-cell-dependent and indirect gut-brain axis-dependent pathways. However, little is known about the mode of action of the GLP-1 receptor agonist lixisenatide. We studied the effects of lixisenatide (intraperitoneal injection) on insulin secretion, gastric emptying, vagus nerve activity, and brain c-Fos activation in naive, chronically vagotomized, GLP-1 receptor knockout (KO), high-fat diet-fed diabetic mice, or db/db mice. Lixisenatide dose-dependently increased oral glucose-induced insulin secretion that is correlated with a decrease of glycemia. In addition, lixisenatide inhibited gastric emptying. These effects of lixisenatide were abolished in vagotomized mice, characterized by a delay of gastric emptying and in GLP-1 receptor KO mice. Intraperitoneal administration of lixisenatide also increased the vagus nerve firing rate and the number of c-Fos-labeled neurons in the nucleus tractus solitarius (NTS) of the brainstem. In diabetic mouse models, lixisenatide increased the firing rate of the vagus nerve when administrated simultaneously to an intraduodenal glucose. It increased also insulin secretion and c-Fos activation in the NTS. Altogether, our findings show that lixisenatide requires a functional vagus nerve and neuronal gut-brain-islets axis as well as the GLP-1 receptor to regulate glucose-induced insulin secretion in healthy and diabetic mice. NEW & NOTEWORTHY Lixisenatide is an agonist of the glucagon-like protein (GLP)-1 receptor, modified from exendin 4, used to treat type 2 diabetic patients. However, whereas the mode of action of endogenous GLP-1 is extensively studied, the mode of action of the GLP-1 analog lixisenatide is poorly understood. Here, we demonstrated that lixisenatide activates the vagus nerve and recruits the gut-brain axis through the GLP-1 receptor to decrease gastric emptying and stimulate insulin secretion to improve glycemia.
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Affiliation(s)
- Julie Charpentier
- Institut National de la Santé et de la Recherche Médicale , Toulouse , France.,Université Paul Sabatier, Unité Mixte de Recherche 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse Cedex, France
| | - Aurélie Waget
- Institut National de la Santé et de la Recherche Médicale , Toulouse , France.,Université Paul Sabatier, Unité Mixte de Recherche 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse Cedex, France
| | - Pascale Klopp
- Institut National de la Santé et de la Recherche Médicale , Toulouse , France.,Université Paul Sabatier, Unité Mixte de Recherche 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse Cedex, France
| | - Christophe Magnan
- Sorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8251, Paris , France
| | - Céline Cruciani-Guglielmacci
- Sorbonne Paris Cité, Université Denis Diderot, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8251, Paris , France
| | - Shin Jae Lee
- Physiology and Behavior Laboratory, Institute of Food, Nutrition, and Health, Eidgenössische Technische Hochschule Zürich, Switzerland
| | - Rémy Burcelin
- Institut National de la Santé et de la Recherche Médicale , Toulouse , France.,Université Paul Sabatier, Unité Mixte de Recherche 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse Cedex, France
| | - Estelle Grasset
- Institut National de la Santé et de la Recherche Médicale , Toulouse , France.,Université Paul Sabatier, Unité Mixte de Recherche 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse Cedex, France
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13
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Coucha M, Abdelsaid M, Ward R, Abdul Y, Ergul A. Impact of Metabolic Diseases on Cerebral Circulation: Structural and Functional Consequences. Compr Physiol 2018; 8:773-799. [PMID: 29687902 DOI: 10.1002/cphy.c170019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Metabolic diseases including obesity, insulin resistance, and diabetes have profound effects on cerebral circulation. These diseases not only affect the architecture of cerebral blood arteries causing adverse remodeling, pathological neovascularization, and vasoregression but also alter the physiology of blood vessels resulting in compromised myogenic reactivity, neurovascular uncoupling, and endothelial dysfunction. Coupled with the disruption of blood brain barrier (BBB) integrity, changes in blood flow and microbleeds into the brain rapidly occur. This overview is organized into sections describing cerebrovascular architecture, physiology, and BBB in these diseases. In each section, we review these properties starting with larger arteries moving into smaller vessels. Where information is available, we review in the order of obesity, insulin resistance, and diabetes. We also tried to include information on biological variables such as the sex of the animal models noted since most of the information summarized was obtained using male animals. © 2018 American Physiological Society. Compr Physiol 8:773-799, 2018.
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Affiliation(s)
- Maha Coucha
- South University, School of Pharmacy, Savannah, Georgia, USA
| | | | - Rebecca Ward
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Yasir Abdul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Adviye Ergul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
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14
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Jiang X, Andjelkovic AV, Zhu L, Yang T, Bennett MVL, Chen J, Keep RF, Shi Y. Blood-brain barrier dysfunction and recovery after ischemic stroke. Prog Neurobiol 2017; 163-164:144-171. [PMID: 28987927 DOI: 10.1016/j.pneurobio.2017.10.001] [Citation(s) in RCA: 522] [Impact Index Per Article: 74.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/30/2017] [Accepted: 10/02/2017] [Indexed: 01/06/2023]
Abstract
The blood-brain barrier (BBB) plays a vital role in regulating the trafficking of fluid, solutes and cells at the blood-brain interface and maintaining the homeostatic microenvironment of the CNS. Under pathological conditions, such as ischemic stroke, the BBB can be disrupted, followed by the extravasation of blood components into the brain and compromise of normal neuronal function. This article reviews recent advances in our knowledge of the mechanisms underlying BBB dysfunction and recovery after ischemic stroke. CNS cells in the neurovascular unit, as well as blood-borne peripheral cells constantly modulate the BBB and influence its breakdown and repair after ischemic stroke. The involvement of stroke risk factors and comorbid conditions further complicate the pathogenesis of neurovascular injury by predisposing the BBB to anatomical and functional changes that can exacerbate BBB dysfunction. Emphasis is also given to the process of long-term structural and functional restoration of the BBB after ischemic injury. With the development of novel research tools, future research on the BBB is likely to reveal promising potential therapeutic targets for protecting the BBB and improving patient outcome after ischemic stroke.
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Affiliation(s)
- Xiaoyan Jiang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | | | - Ling Zhu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tuo Yang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael V L Bennett
- State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jun Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Yejie Shi
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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15
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Sajja RK, Prasad S, Tang S, Kaisar MA, Cucullo L. Blood-brain barrier disruption in diabetic mice is linked to Nrf2 signaling deficits: Role of ABCB10? Neurosci Lett 2017; 653:152-158. [PMID: 28572033 DOI: 10.1016/j.neulet.2017.05.059] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/26/2017] [Accepted: 05/26/2017] [Indexed: 01/08/2023]
Abstract
Blood-brain barrier (BBB) damage is a critical neurovascular complication of diabetes mellitus that adversely affects the CNS health and function. Previously, we showed the protective role of NF-E2 related factor-2 (Nrf2), a redox sensitive transcription factor, in regulation of BBB integrity. Given the pathogenic role of mitochondrial oxidative stress in diabetes-related microvascular complications, we focused on assessing: 1) the impact of diabetes on brain Nrf2 in correlation with BBB permeability and 2) Nrf2-dependent regulation of the mitochondrial transporter ABCB10, an essential player in mitochondrial function and redox balance at BBB endothelium. Using live animal fluorescence imaging, we demonstrated a strong increase in BBB permeability to 70kDa dextran in db/db diabetic mice that correlated with significant down-regulation of brain Nrf2 protein. Further, Nrf2 gene silencing in human BBB endothelial cells markedly suppressed ABCB10 protein, while Nrf2 activation by sulforaphane up-regulated ABCB10 expression. Interestingly, ABCB10 knockdown resulted in a strong-induction of Nrf2 driven anti-oxidant responses as evidenced by increased expression of Nrf2 and its downstream targets. Nrf2 or ABCB10 silencing elevated endothelial-monocyte adhesion suggesting an activated inflammatory cascade. Thus, our results demonstrate a novel mechanism of ABCB10 regulation driven by Nrf2. In summary, Nrf2 dysregulation and ABCB10 suppression could likely mediate endothelial oxidative/inflammatory stress and BBB disruption in diabetic subjects.
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Affiliation(s)
- Ravi K Sajja
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79109, USA.
| | - Shikha Prasad
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79109, USA.
| | - Suni Tang
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79109, USA.
| | - Mohammad A Kaisar
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79109, USA.
| | - Luca Cucullo
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79109, USA.
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16
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Ueno M. Elucidation of mechanism of blood-brain barrier damage for prevention and treatment of vascular dementia. Rinsho Shinkeigaku 2017; 57:95-109. [PMID: 28228623 DOI: 10.5692/clinicalneurol.cn-001004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
It is well-known that the blood-brain barrier (BBB) plays significant roles in transporting intravascular substances into the brain. The BBB in cerebral capillaries essentially impedes the influx of intravascular compounds from the blood to the brain, while nutritive substances, such as glucose, can be selectively transported through several types of influx transporters in endothelial cells. In the choroid plexus, intravascular substances can invade the parenchyma as fenestrations exist in endothelial cells of capillaries. However, the substances cannot invade the ventricles easily as there are tight junctions between epithelial cells in the choroid plexus. This restricted movement of the substances across the cytoplasm of the epithelial cells constitutes a blood-cerebrospinal fluid barrier (BCSFB). In the brain, there are circumventricular organs, in which the barrier function is imperfect in capillaries. Accordingly, it is reasonable to consider that intravascular substances can move in and around the parenchyma of the organs. Actually, it was reported in mice that intravascular substances moved in the corpus callosum, medial portions of the hippocampus, and periventricular areas via the subfornical organs or the choroid plexus. Regarding pathways of intracerebral interstitial and cerebrospinal fluids to the outside of the brain, two representative drainage pathways, or perivascular drainage and glymphatic pathways, are being established. The first is the pathway in a retrograde direction to the blood flow through the basement membrane in walls of cerebral capillaries, the tunica media of arteries, and the vessels walls of the internal carotid artery. The second is in an anterograde direction to blood flow through the para-arterial routes, aquaporin 4-dependent transport through the astroglial cytoplasm, and para-venous routes, and then the fluids drain into the subarachnoid CSF. These fluids are finally considered to drain into the cervical lymph nodes or veins. These clearance pathways may play a role in maintenance of the barrier in the entire brain. Obstruction of the passage of fluids through the perivascular drainage and glymphatic pathways as well as damage of the BBB and BCSFB may induce several kinds of brain disorders, such as vascular dementia. In this review, we focus on the relationship between damage of the barriers and the pathogenesis of vascular dementia and introduce recent findings including our experimental data using animal models.
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Affiliation(s)
- Masaki Ueno
- Inflammation Pathology, Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University
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