1001
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Park JC, Baik SH, Han SH, Cho HJ, Choi H, Kim HJ, Choi H, Lee W, Kim DK, Mook-Jung I. Annexin A1 restores Aβ 1-42 -induced blood-brain barrier disruption through the inhibition of RhoA-ROCK signaling pathway. Aging Cell 2017; 16:149-161. [PMID: 27633771 PMCID: PMC5242298 DOI: 10.1111/acel.12530] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2016] [Indexed: 12/15/2022] Open
Abstract
The blood–brain barrier (BBB) is composed of brain capillary endothelial cells and has an important role in maintaining homeostasis of the brain separating the blood from the parenchyma of the central nervous system (CNS). It is widely known that disruption of the BBB occurs in various neurodegenerative diseases, including Alzheimer's disease (AD). Annexin A1 (ANXA1), an anti‐inflammatory messenger, is expressed in brain endothelial cells and regulates the BBB integrity. However, its role and mechanism for protecting BBB in AD have not been identified. We found that β‐Amyloid 1‐42 (Aβ42)‐induced BBB disruption was rescued by human recombinant ANXA1 (hrANXA1) in the murine brain endothelial cell line bEnd.3. Also, ANXA1 was decreased in the bEnd.3 cells, the capillaries of 5XFAD mice, and the human serum of patients with AD. To find out the mechanism by which ANXA1 recovers the BBB integrity in AD, the RhoA‐ROCK signaling pathway was examined in both Aβ42‐treated bEnd.3 cells and the capillaries of 5XFAD mice as RhoA was activated in both cases. RhoA inhibitors alleviated Aβ42‐induced BBB disruption and constitutively overexpressed RhoA‐GTP (active form of RhoA) attenuated the protective effect of ANXA1. When pericytes were cocultured with bEnd.3 cells, Aβ42‐induced RhoA activation of bEnd.3 cells was inhibited by the secretion of ANXA1 from pericytes. Taken together, our results suggest that ANXA1 restores Aβ42‐induced BBB disruption through inhibition of RhoA‐ROCK signaling pathway and we propose ANXA1 as a therapeutic reagent, protecting against the breakdown of the BBB in AD.
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Affiliation(s)
- Jong-Chan Park
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Sung Hoon Baik
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Sun-Ho Han
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Hyun Jin Cho
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Hyunjung Choi
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Haeng Jun Kim
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Heesun Choi
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Wonik Lee
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Dong Kyu Kim
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
| | - Inhee Mook-Jung
- Department of Biochemistry and Biomedical Sciences; College of Medicine; Seoul National University; Seoul 110-799 Korea
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1002
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Abstract
T cells are required for immune surveillance of the central nervous system (CNS); however, they can also induce severe immunopathology in the context of both viral infections and autoimmunity. The mechanisms that are involved in the priming and recruitment of T cells to the CNS are only partially understood, but there has been renewed interest in this topic since the 'rediscovery' of lymphatic drainage from the CNS. Moreover, tissue-resident memory T cells have been detected in the CNS and are increasingly recognized as an autonomous line of host defence. In this Review, we highlight the main mechanisms that are involved in the priming and CNS recruitment of CD4+ T cells, CD8+ T cells and regulatory T cells. We also consider the plasticity of T cell responses in the CNS, with a focus on viral infection and autoimmunity.
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1003
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Endothelial Wnt/β-catenin signaling reduces immune cell infiltration in multiple sclerosis. Proc Natl Acad Sci U S A 2017; 114:E1168-E1177. [PMID: 28137846 DOI: 10.1073/pnas.1609905114] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Disruption of the blood-brain barrier (BBB) is a defining and early feature of multiple sclerosis (MS) that directly damages the central nervous system (CNS), promotes immune cell infiltration, and influences clinical outcomes. There is an urgent need for new therapies to protect and restore BBB function, either by strengthening endothelial tight junctions or suppressing endothelial vesicular transcytosis. Although wingless integrated MMTV (Wnt)/β-catenin signaling plays an essential role in BBB formation and maintenance in healthy CNS, its role in BBB repair in neurologic diseases such as MS remains unclear. Using a Wnt/β-catenin reporter mouse and several downstream targets, we demonstrate that the Wnt/β-catenin pathway is up-regulated in CNS endothelial cells in both human MS and the mouse model experimental autoimmune encephalomyelitis (EAE). Increased Wnt/β-catenin activity in CNS blood vessels during EAE progression correlates with up-regulation of neuronal Wnt3 expression, as well as breakdown of endothelial cell junctions. Genetic inhibition of the Wnt/β-catenin pathway in CNS endothelium before disease onset exacerbates the clinical presentation of EAE, CD4+ T-cell infiltration into the CNS, and demyelination by increasing expression of vascular cell adhesion molecule-1 and the transcytosis protein Caveolin-1 and promoting endothelial transcytosis. However, Wnt signaling attenuation does not affect the progressive degradation of tight junction proteins or paracellular BBB leakage. These results suggest that reactivation of Wnt/β-catenin signaling in CNS vessels during EAE/MS partially restores functional BBB integrity and limits immune cell infiltration into the CNS.
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1004
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Boutin ME, Kramer LL, Livi LL, Brown T, Moore C, Hoffman-Kim D. A three-dimensional neural spheroid model for capillary-like network formation. J Neurosci Methods 2017; 299:55-63. [PMID: 28143748 DOI: 10.1016/j.jneumeth.2017.01.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 01/19/2017] [Accepted: 01/24/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND In vitro three-dimensional neural spheroid models have an in vivo-like cell density, and have the potential to reduce animal usage and increase experimental throughput. The aim of this study was to establish a spheroid model to study the formation of capillary-like networks in a three-dimensional environment that incorporates both neuronal and glial cell types, and does not require exogenous vasculogenic growth factors. NEW METHOD We created self-assembled, scaffold-free cellular spheroids using primary-derived postnatal rodent cortex as a cell source. The interactions between relevant neural cell types, basement membrane proteins, and endothelial cells were characterized by immunohistochemistry. Transmission electron microscopy was used to determine if endothelial network structures had lumens. RESULTS Endothelial cells within cortical spheroids assembled into capillary-like networks with lumens. Networks were surrounded by basement membrane proteins, including laminin, fibronectin and collagen IV, as well as key neurovascular cell types. COMPARISON WITH EXISTING METHOD(S) Existing in vitro models of the cortical neurovascular environment study monolayers of endothelial cells, either on transwell inserts or coating cellular spheroids. These models are not well suited to study vasculogenesis, a process hallmarked by endothelial cell cord formation and subsequent lumenization. CONCLUSIONS The neural spheroid is a new model to study the formation of endothelial cell capillary-like structures in vitro within a high cell density three-dimensional environment that contains both neuronal and glial populations. This model can be applied to investigate vascular assembly in healthy or disease states, such as stroke, traumatic brain injury, or neurodegenerative disorders.
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Affiliation(s)
- Molly E Boutin
- Center for Biomedical Engineering, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States.
| | - Liana L Kramer
- Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States.
| | - Liane L Livi
- Center for Biomedical Engineering, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States.
| | - Tyler Brown
- Department of Neuroscience, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Brown Institute for Brain Science, 175 Meeting Street, Brown University, Providence, RI, 02912, United States.
| | - Christopher Moore
- Department of Neuroscience, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Brown Institute for Brain Science, 175 Meeting Street, Brown University, Providence, RI, 02912, United States.
| | - Diane Hoffman-Kim
- Center for Biomedical Engineering, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Brown Institute for Brain Science, 175 Meeting Street, Brown University, Providence, RI, 02912, United States.
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1005
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The vasculature as a neural stem cell niche. Neurobiol Dis 2017; 107:4-14. [PMID: 28132930 DOI: 10.1016/j.nbd.2017.01.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 01/06/2017] [Accepted: 01/25/2017] [Indexed: 12/31/2022] Open
Abstract
Neural stem cells (NSCs) are multipotent, self-renewing progenitors that generate progeny that differentiate into neurons and glia. NSCs in the adult mammalian brain are generally quiescent. Environmental stimuli such as learning or exercise can activate quiescent NSCs, inducing them to proliferate and produce new neurons and glia. How are these behaviours coordinated? The neurovasculature, the circulatory system of the brain, is a key component of the NSC microenvironment, or 'niche'. Instructive signals from the neurovasculature direct NSC quiescence, proliferation, self-renewal and differentiation. During ageing, a breakdown in the niche accompanies NSC dysfunction and cognitive decline. There is much interest in reversing these changes and enhancing NSC activity by targeting the neurovasculature therapeutically. Here we discuss principles of neurovasculature-NSC crosstalk, and the implications for the design of NSC-based therapies. We also consider the emerging contributions to this field of the model organism Drosophila melanogaster.
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1006
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Di Pardo A, Amico E, Scalabrì F, Pepe G, Castaldo S, Elifani F, Capocci L, De Sanctis C, Comerci L, Pompeo F, D’Esposito M, Filosa S, Crispi S, Maglione V. Impairment of blood-brain barrier is an early event in R6/2 mouse model of Huntington Disease. Sci Rep 2017; 7:41316. [PMID: 28117381 PMCID: PMC5259798 DOI: 10.1038/srep41316] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/16/2016] [Indexed: 01/30/2023] Open
Abstract
Blood-brain barrier (BBB) breakdown, due to the concomitant disruption of the tight junctions (TJs), normally required for the maintenance of BBB function, and to the altered transport of molecules between blood and brain and vice-versa, has been suggested to significantly contribute to the development and progression of different brain disorders including Huntington's disease (HD). Although the detrimental consequence the BBB breakdown may have in the clinical settings, the timing of its alteration remains elusive for many neurodegenerative diseases. In this study we demonstrate for the first time that BBB disruption in HD is not confined to established symptoms, but occurs early in the disease progression. Despite the obvious signs of impaired BBB permeability were only detectable in concomitance with the onset of the disease, signs of deranged TJs integrity occur precociously in the disease and precede the onset of overt symptoms. To our perspective this finding may add a new dimension to the horizons of pathological mechanisms underlying this devastating disease, however much remains to be elucidated for understanding how specific BBB drug targets can be approached in the future.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Laura Comerci
- Institute of Biosciences and Bioresources, IBBR, CNR, Napoli, Italy
| | | | - Maurizio D’Esposito
- IRCCS Neuromed, Pozzilli, Italy
- Institute of Genetics and Biophysics “A. Buzzati-Traverso”, Naples, Italy
| | - Stefania Filosa
- IRCCS Neuromed, Pozzilli, Italy
- Institute of Biosciences and Bioresources, IBBR, CNR, Napoli, Italy
| | - Stefania Crispi
- Institute of Biosciences and Bioresources, IBBR, CNR, Napoli, Italy
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1007
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Müller K, Courtois G, Ursini MV, Schwaninger M. New Insight Into the Pathogenesis of Cerebral Small-Vessel Diseases. Stroke 2017; 48:520-527. [PMID: 28082670 DOI: 10.1161/strokeaha.116.012888] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Kristin Müller
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.)
| | - Gilles Courtois
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.)
| | - Matilde Valeria Ursini
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.)
| | - Markus Schwaninger
- From the Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Germany (K.M., M.S.); INSERM U1038/BIG, CEA, Grenoble, France (G.C.); and Institute of Genetics and Biophysics, "Adriano Buzzati-Traverso", IGB-CNR, Naples, Italy (M.V.U.).
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1008
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Erdő F, Denes L, de Lange E. Age-associated physiological and pathological changes at the blood-brain barrier: A review. J Cereb Blood Flow Metab 2017; 37:4-24. [PMID: 27837191 PMCID: PMC5363756 DOI: 10.1177/0271678x16679420] [Citation(s) in RCA: 284] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 10/21/2016] [Accepted: 10/24/2016] [Indexed: 12/13/2022]
Abstract
The age-associated decline of the neurological and cognitive functions becomes more and more serious challenge for the developed countries with the increasing number of aged populations. The morphological and biochemical changes in the aging brain are the subjects of many extended research projects worldwide for a long time. However, the crucial role of the blood-brain barrier (BBB) impairment and disruption in the pathological processes in age-associated neurodegenerative disorders received special attention just for a few years. This article gives an overview on the major elements of the blood-brain barrier and its supporting mechanisms and also on their alterations during development, physiological aging process and age-associated neurodegenerative disorders (Alzheimer's disease, multiple sclerosis, Parkinson's disease, pharmacoresistant epilepsy). Besides the morphological alterations of the cellular elements (endothelial cells, astrocytes, pericytes, microglia, neuronal elements) of the BBB and neurovascular unit, the changes of the barrier at molecular level (tight junction proteins, adheres junction proteins, membrane transporters, basal lamina, extracellular matrix) are also summarized. The recognition of new players and initiators of the process of neurodegeneration at the level of the BBB may offer new avenues for novel therapeutic approaches for the treatment of numerous chronic neurodegenerative disorders currently without effective medication.
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Affiliation(s)
- Franciska Erdő
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - László Denes
- Institute of Pharmacology & Pharmacotherapy, Semmelweis University, Budapest, Hungary
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1009
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Nikolakopoulou AM, Zhao Z, Montagne A, Zlokovic BV. Regional early and progressive loss of brain pericytes but not vascular smooth muscle cells in adult mice with disrupted platelet-derived growth factor receptor-β signaling. PLoS One 2017; 12:e0176225. [PMID: 28441414 PMCID: PMC5404855 DOI: 10.1371/journal.pone.0176225] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/18/2017] [Indexed: 11/19/2022] Open
Abstract
Pericytes regulate key neurovascular functions of the brain. Studies in pericyte-deficient transgenic mice with aberrant signaling between endothelial-derived platelet-derived growth factor BB (PDGF-BB) and platelet-derived growth factor receptor β (PDGFRβ) in pericytes have contributed to better understanding of the role of pericytes in the brain. Here, we studied PdgfrβF7/F7 mice, which carry seven point mutations that disrupt PDGFRβ signaling causing loss of pericytes and vascular smooth muscle cells (VSMCs) in the developing brain. We asked whether these mice have a stable or progressive vascular phenotype after birth, and whether both pericyte and VSMCs populations are affected in the adult brain. We found an early and progressive region-dependent loss of brain pericytes, microvascular reductions and blood-brain barrier (BBB) breakdown, which were more pronounced in the cortex, hippocampus and striatum than in the thalamus, whereas VSMCs population remained unaffected at the time when pericyte loss was already established. For example, compared to age-matched controls, PdgfrβF7/F7 mice between 4-6 and 36-48 weeks of age developed a region-dependent loss in pericyte coverage (22-46, 24-44 and 4-31%) and cell numbers (36-49, 34-64 and 11-36%), reduction in capillary length (20-39, 13-46 and 1-30%), and an increase in extravascular fibrinogen-derived deposits (3.4-5.2, 2.8-4.1 and 0-3.6-fold) demonstrating BBB breakdown in the cortex, hippocampus and thalamus, respectively. Capillary reductions and BBB breakdown correlated with loss of pericyte coverage. Our data suggest that PdgfrβF7/F7 mice develop an aggressive and rapid vascular phenotype without appreciable early involvement of VSMCs, therefore providing a valuable model to study regional effects of pericyte loss on brain vascular and neuronal functions. This model could be a useful tool for future studies directed at understanding the role of pericytes in the pathogenesis of neurological disorders associated with pericyte loss such as vascular dementia, Alzheimer's disease, amyotrophic lateral sclerosis, stroke and human immunodeficiency virus-associated neurocognitive disorder.
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Affiliation(s)
- Angeliki Maria Nikolakopoulou
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Zhen Zhao
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Axel Montagne
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Berislav V. Zlokovic
- Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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1010
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Laviña B. Brain Vascular Imaging Techniques. Int J Mol Sci 2016; 18:ijms18010070. [PMID: 28042833 PMCID: PMC5297705 DOI: 10.3390/ijms18010070] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/13/2016] [Accepted: 12/26/2016] [Indexed: 12/13/2022] Open
Abstract
Recent major improvements in a number of imaging techniques now allow for the study of the brain in ways that could not be considered previously. Researchers today have well-developed tools to specifically examine the dynamic nature of the blood vessels in the brain during development and adulthood; as well as to observe the vascular responses in disease situations in vivo. This review offers a concise summary and brief historical reference of different imaging techniques and how these tools can be applied to study the brain vasculature and the blood-brain barrier integrity in both healthy and disease states. Moreover, it offers an overview on available transgenic animal models to study vascular biology and a description of useful online brain atlases.
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Affiliation(s)
- Bàrbara Laviña
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, 75185 Uppsala, Sweden.
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1011
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Kelava I, Lancaster MA. Dishing out mini-brains: Current progress and future prospects in brain organoid research. Dev Biol 2016; 420:199-209. [PMID: 27402594 PMCID: PMC5161139 DOI: 10.1016/j.ydbio.2016.06.037] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/16/2016] [Accepted: 06/25/2016] [Indexed: 01/15/2023]
Abstract
The ability to model human brain development in vitro represents an important step in our study of developmental processes and neurological disorders. Protocols that utilize human embryonic and induced pluripotent stem cells can now generate organoids which faithfully recapitulate, on a cell-biological and gene expression level, the early period of human embryonic and fetal brain development. In combination with novel gene editing tools, such as CRISPR, these methods represent an unprecedented model system in the field of mammalian neural development. In this review, we focus on the similarities of current organoid methods to in vivo brain development, discuss their limitations and potential improvements, and explore the future venues of brain organoid research.
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Affiliation(s)
- Iva Kelava
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, CB2 0QH Cambridge, United Kingdom
| | - Madeline A Lancaster
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, CB2 0QH Cambridge, United Kingdom.
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1012
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1013
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Abstract
Defined genetic models based on human pluripotent stem cells have opened new avenues for understanding disease mechanisms and drug screening. Many of these models assume cell-autonomous mechanisms of disease but it is possible that disease phenotypes or drug responses will only be evident if all cellular and extracellular components of a tissue are present and functionally mature. To derive optimal benefit from such models, complex multicellular structures with vascular components that mimic tissue niches will thus likely be necessary. Here we consider emerging research creating human tissue mimics and provide some recommendations for moving the field forward.
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1014
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Reinhold AK, Rittner HL. Barrier function in the peripheral and central nervous system-a review. Pflugers Arch 2016; 469:123-134. [PMID: 27957611 DOI: 10.1007/s00424-016-1920-8] [Citation(s) in RCA: 181] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/23/2016] [Accepted: 11/27/2016] [Indexed: 11/29/2022]
Abstract
The peripheral (PNS) and central nervous system (CNS) are delicate structures, highly sensitive to homeostatic changes-and crucial for basic vital functions. Thus, a selection of barriers ensures the protection of the nervous system from noxious blood-borne or surrounding stimuli. In this chapter, anatomy and functioning of the blood-nerve (BNB), the blood-brain (BBB), and the blood-spinal cord barriers (BSCB) are presented and the key tight junction (TJ) proteins described: claudin-1, claudin-3, claudin-5, claudin-11, claudin-12, claudin-19, occludin, Zona occludens-1 (ZO-1), and tricellulin are by now identified as relevant for nerval barriers. Different diseases can lead to or be accompanied by neural barrier disruption, and impairment of these barriers worsens pathology. Peripheral nerve injury and inflammatory polyneuropathy cause an increased permeability of BNB as well as BSCB, while, e.g., diseases of the CNS such as amyotrophic lateral sclerosis, multiple sclerosis, spinal cord injury, or Alzheimer's disease can progress and worsen through barrier dysfunction. Moreover, the complex role and regulation of the BBB after ischemic stroke is described. On the other side, PNS and CNS barriers hamper the delivery of drugs in diseases when the barrier is intact, e.g., in certain neurodegenerative diseases or inflammatory pain. Understanding of the barrier - regulating processes has already lead to the discovery of new molecules as drug enhancers. In summary, the knowledge of all of these mechanisms might ultimately lead to the invention of drugs to control barrier function to help ameliorating or curing neurological diseases.
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Affiliation(s)
- A K Reinhold
- Department of Anesthesiology, University Hospitals Wuerzburg, Oberduerrbacher Str. 6, 97080, Wuerzburg, Germany.
| | - H L Rittner
- Department of Anesthesiology, University Hospitals Wuerzburg, Oberduerrbacher Str. 6, 97080, Wuerzburg, Germany
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1015
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Janelidze S, Hertze J, Nägga K, Nilsson K, Nilsson C, Wennström M, van Westen D, Blennow K, Zetterberg H, Hansson O. Increased blood-brain barrier permeability is associated with dementia and diabetes but not amyloid pathology or APOE genotype. Neurobiol Aging 2016; 51:104-112. [PMID: 28061383 PMCID: PMC5754327 DOI: 10.1016/j.neurobiolaging.2016.11.017] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/07/2016] [Accepted: 11/25/2016] [Indexed: 01/09/2023]
Abstract
Blood-brain barrier (BBB) dysfunction might be an important component of many neurodegenerative disorders. In this study, we investigated its role in dementia using large clinical cohorts. The cerebrospinal fluid (CSF)/plasma albumin ratio (Qalb), an indicator of BBB (and blood-CSF barrier) permeability, was measured in a total of 1015 individuals. The ratio was increased in patients with Alzheimer's disease, dementia with Lewy bodies or Parkinson's disease dementia, subcortical vascular dementia, and frontotemporal dementia compared with controls. However, this measure was not changed during preclinical or prodromal Alzheimer's disease and was not associated with amyloid positron emission tomography or APOE genotype. The Qalb was increased in diabetes mellitus and correlated positively with CSF biomarkers of angiogenesis and endothelial dysfunction (vascular endothelial growth factor, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1). In healthy elderly, high body mass index and waist-hip ratio predicted increased Qalb 20 years later. In summary, BBB permeability is increased in major dementia disorders but does not relate to amyloid pathology or APOE genotype. Instead, BBB impairment may be associated with diabetes and brain microvascular damage.
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Affiliation(s)
- Shorena Janelidze
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
| | - Joakim Hertze
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Katarina Nägga
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Karin Nilsson
- Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Christer Nilsson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden; Department of Neurology, Skåne University Hospital, Lund, Sweden
| | | | - Malin Wennström
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Wallenberg Laboratory, Malmö, Sweden
| | - Danielle van Westen
- Department of Clinical Sciences, Diagnostic radiology, Lund University, Lund, Sweden; Imaging and Function, Skåne University Health Care, Lund, Sweden
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden.
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1016
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Stranahan AM, Hao S, Dey A, Yu X, Baban B. Blood-brain barrier breakdown promotes macrophage infiltration and cognitive impairment in leptin receptor-deficient mice. J Cereb Blood Flow Metab 2016; 36:2108-2121. [PMID: 27034250 PMCID: PMC5363667 DOI: 10.1177/0271678x16642233] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 03/02/2016] [Accepted: 03/07/2016] [Indexed: 01/03/2023]
Abstract
Accumulating evidence indicates that obesity accelerates the onset of cognitive decline. While mechanisms are still being identified, obesity promotes peripheral inflammation and increases blood-brain barrier (BBB) permeability. However, no studies have manipulated vascular permeability in obesity to determine whether BBB breakdown underlies memory deficits. Protein kinase Cβ (PKCβ) activation destabilizes the BBB, and we used a PKCβ inhibitor (Enzastaurin) to block BBB leakiness in leptin receptor-deficient (db/db) mice. Enzastaurin reversed BBB breakdown in db/db mice and normalized hippocampal function without affecting obesity or metabolism. Flow cytometric analysis of forebrain mononuclear cells (FMCs) from db/db mice revealed macrophage infiltration and induction of the activation marker MHCII in microglia and macrophages. Enzastaurin eliminated macrophage infiltration and MHCII induction, and protein array profiling revealed parallel reductions in IL1β, IL6, MCP1, and TNFα. To investigate whether these signals attract peripheral monocytes, FMCs from Wt and db/db mice were plated below migration inserts containing peritoneal macrophages. Peritoneal macrophages from db/db mice exhibit increases in transmigration that were blocked by recombinant IL1RA. These studies indicate that BBB breakdown impairs cognition in obesity and diabetes by allowing macrophage infiltration, with a potential role for IL1β in trafficking of peripheral monocytes into the brain.
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Affiliation(s)
- Alexis M Stranahan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Shuai Hao
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Aditi Dey
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Xiaolin Yu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Babak Baban
- Department of Oral Biology, Medical College of Georgia, Georgia Regents University Augusta, GA, USA
- Plastic Surgery Section, Department of Surgery Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
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1017
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Faraco G, Sugiyama Y, Lane D, Garcia-Bonilla L, Chang H, Santisteban MM, Racchumi G, Murphy M, Van Rooijen N, Anrather J, Iadecola C. Perivascular macrophages mediate the neurovascular and cognitive dysfunction associated with hypertension. J Clin Invest 2016; 126:4674-4689. [PMID: 27841763 DOI: 10.1172/jci86950] [Citation(s) in RCA: 224] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 09/30/2016] [Indexed: 01/05/2023] Open
Abstract
Hypertension is a leading risk factor for dementia, but the mechanisms underlying its damaging effects on the brain are poorly understood. Due to a lack of energy reserves, the brain relies on continuous delivery of blood flow to its active regions in accordance with their dynamic metabolic needs. Hypertension disrupts these vital regulatory mechanisms, leading to the neuronal dysfunction and damage underlying cognitive impairment. Elucidating the cellular bases of these impairments is essential for developing new therapies. Perivascular macrophages (PVMs) represent a distinct population of resident brain macrophages that serves key homeostatic roles but also has the potential to generate large amounts of reactive oxygen species (ROS). Here, we report that PVMs are critical in driving the alterations in neurovascular regulation and attendant cognitive impairment in mouse models of hypertension. This effect was mediated by an increase in blood-brain barrier permeability that allowed angiotensin II to enter the perivascular space and activate angiotensin type 1 receptors in PVMs, leading to production of ROS through the superoxide-producing enzyme NOX2. These findings unveil a pathogenic role of PVMs in the neurovascular and cognitive dysfunction associated with hypertension and identify these cells as a putative therapeutic target for diseases associated with cerebrovascular oxidative stress.
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1018
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A Novel Iron Chelator-Radical Scavenger Ameliorates Motor Dysfunction and Improves Life Span and Mitochondrial Biogenesis in SOD1G93A ALS Mice. Neurotox Res 2016; 31:230-244. [DOI: 10.1007/s12640-016-9677-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/05/2016] [Accepted: 10/13/2016] [Indexed: 12/12/2022]
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1019
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Lewandowski SA, Fredriksson L, Lawrence DA, Eriksson U. Pharmacological targeting of the PDGF-CC signaling pathway for blood-brain barrier restoration in neurological disorders. Pharmacol Ther 2016; 167:108-119. [PMID: 27524729 PMCID: PMC5341142 DOI: 10.1016/j.pharmthera.2016.07.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 07/25/2016] [Indexed: 12/12/2022]
Abstract
Neurological disorders account for a majority of non-malignant disability in humans and are often associated with dysfunction of the blood-brain barrier (BBB). Recent evidence shows that despite apparent variation in the origin of neural damage, the central nervous system has a common injury response mechanism involving platelet-derived growth factor (PDGF)-CC activation in the neurovascular unit and subsequent dysfunction of BBB integrity. Inhibition of PDGF-CC signaling with imatinib in mice has been shown to prevent BBB dysfunction and have neuroprotective effects in acute damage conditions, including traumatic brain injury, seizures or stroke, as well as in neurodegenerative diseases that develop over time, including multiple sclerosis and amyotrophic lateral sclerosis. Stroke and traumatic injuries are major risk factors for age-associated neurodegenerative disorders and we speculate that restoring BBB properties through PDGF-CC inhibition might provide a common therapeutic opportunity for treatment of both acute and progressive neuropathology in humans. In this review we will summarize what is known about the role of PDGF-CC in neurovascular signaling events and the variety of seemingly different neuropathologies it is involved in. We will also discuss the pharmacological means of therapeutic interventions for anti-PDGF-CC therapy and ongoing clinical trials. In summary: inhibition of PDGF-CC signaling can be protective for immediate injury and decrease the long-term neurodegenerative consequences.
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Affiliation(s)
- Sebastian A Lewandowski
- Tissue Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Scheeles v. 2, 17177, Stockholm, Sweden.
| | - Linda Fredriksson
- Vascular Biology Groups, Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Scheeles v. 2, 17177, Stockholm, Sweden; Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan Medical School, 7301 Medical Science Research Building III, 1150 West Medical Center Drive, Ann Arbor, MI 48109-0644, USA
| | - Daniel A Lawrence
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan Medical School, 7301 Medical Science Research Building III, 1150 West Medical Center Drive, Ann Arbor, MI 48109-0644, USA
| | - Ulf Eriksson
- Tissue Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Scheeles v. 2, 17177, Stockholm, Sweden.
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1020
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Jeltsch-David H, Muller S. Autoimmunity, neuroinflammation, pathogen load: A decisive crosstalk in neuropsychiatric SLE. J Autoimmun 2016; 74:13-26. [DOI: 10.1016/j.jaut.2016.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 04/21/2016] [Accepted: 04/24/2016] [Indexed: 12/23/2022]
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1021
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Mishra A. Binaural blood flow control by astrocytes: listening to synapses and the vasculature. J Physiol 2016; 595:1885-1902. [PMID: 27619153 DOI: 10.1113/jp270979] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/15/2016] [Indexed: 12/28/2022] Open
Abstract
Astrocytes are the most common glial cells in the brain with fine processes and endfeet that intimately contact both neuronal synapses and the cerebral vasculature. They play an important role in mediating neurovascular coupling (NVC) via several astrocytic Ca2+ -dependent signalling pathways such as K+ release through BK channels, and the production and release of arachidonic acid metabolites. They are also involved in maintaining the resting tone of the cerebral vessels by releasing ATP and COX-1 derivatives. Evidence also supports a role for astrocytes in maintaining blood pressure-dependent change in cerebrovascular tone, and perhaps also in blood vessel-to-neuron signalling as posited by the 'hemo-neural hypothesis'. Thus, astrocytes are emerging as new stars in preserving the intricate balance between the high energy demand of active neurons and the supply of oxygen and nutrients from the blood by maintaining both resting blood flow and activity-evoked changes therein. Following neuropathology, astrocytes become reactive and many of their key signalling mechanisms are altered, including those involved in NVC. Furthermore, as they can respond to changes in vascular pressure, cardiovascular diseases might exert previously unknown effects on the central nervous system by altering astrocyte function. This review discusses the role of astrocytes in neurovascular signalling in both physiology and pathology, and the impact of these findings on understanding BOLD-fMRI signals.
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Affiliation(s)
- Anusha Mishra
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
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1022
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He L, Vanlandewijck M, Raschperger E, Andaloussi Mäe M, Jung B, Lebouvier T, Ando K, Hofmann J, Keller A, Betsholtz C. Analysis of the brain mural cell transcriptome. Sci Rep 2016; 6:35108. [PMID: 27725773 PMCID: PMC5057134 DOI: 10.1038/srep35108] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/22/2016] [Indexed: 01/20/2023] Open
Abstract
Pericytes, the mural cells of blood microvessels, regulate microvascular development and function and have been implicated in many brain diseases. However, due to a paucity of defining markers, pericyte identification and functional characterization remain ambiguous and data interpretation problematic. In mice carrying two transgenic reporters, Pdgfrb-eGFP and NG2-DsRed, we found that double-positive cells were vascular mural cells, while the single reporters marked additional, but non-overlapping, neuroglial cells. Double-positive cells were isolated by fluorescence-activated cell sorting (FACS) and analyzed by RNA sequencing. To reveal defining patterns of mural cell transcripts, we compared the RNA sequencing data with data from four previously published studies. The meta-analysis provided a conservative catalogue of 260 brain mural cell-enriched gene transcripts. We validated pericyte-specific expression of two novel markers, vitronectin (Vtn) and interferon-induced transmembrane protein 1 (Ifitm1), using fluorescent in situ hybridization and immunohistochemistry. We further analyzed signaling pathways and interaction networks of the pericyte-enriched genes in silico. This work provides novel insight into the molecular composition of brain mural cells. The reported gene catalogue facilitates identification of brain pericytes by providing numerous new candidate marker genes and is a rich source for new hypotheses for future studies of brain mural cell physiology and pathophysiology.
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Affiliation(s)
- Liqun He
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Michael Vanlandewijck
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
- Integrated Cardio Metabolic Centre (ICMC), Karolinska Institute, Novum, SE-141 57 Huddinge, Stockholm, Sweden
| | - Elisabeth Raschperger
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
- Integrated Cardio Metabolic Centre (ICMC), Karolinska Institute, Novum, SE-141 57 Huddinge, Stockholm, Sweden
| | - Maarja Andaloussi Mäe
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Bongnam Jung
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Thibaud Lebouvier
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Koji Ando
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Jennifer Hofmann
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Annika Keller
- Division of Neurosurgery, Zürich University Hospital, Zürich University, Zürich, Switzerland
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
- Integrated Cardio Metabolic Centre (ICMC), Karolinska Institute, Novum, SE-141 57 Huddinge, Stockholm, Sweden
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1023
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Qiu J, Yan Z, Tao K, Li Y, Li Y, Li J, Dong Y, Feng D, Chen H. Sinomenine activates astrocytic dopamine D2 receptors and alleviates neuroinflammatory injury via the CRYAB/STAT3 pathway after ischemic stroke in mice. J Neuroinflammation 2016; 13:263. [PMID: 27724964 PMCID: PMC5057372 DOI: 10.1186/s12974-016-0739-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 09/29/2016] [Indexed: 12/03/2022] Open
Abstract
Background Astrocyte-mediated neuroinflammation plays a critical role in ischemic stroke-induced secondary cerebral injury. Previous studies have suggested that the dopamine D2 receptor (DRD2) acts as a key target in regulating the neuroinflammatory response. However, the underlying molecular mechanisms are still unknown, and effective DRD2 agonists are lacking. In the present study, we examined the anti-inflammatory and neuroprotective effects of sinomenine (Sino), a monomeric compound with potential immunoregulatory properties in nervous system. Methods TTC staining, apoptosis assay, evaluation of brain edema, and neurological assessment were performed in the middle cerebral artery occlusion (MCAO) mouse model. Primary astrocytes exposed to oxygen glucose deprivation (OGD) were used in the in vitro experiments. Quantitative PCR was applied to assess the levels of inflammatory cytokines. Multi-labeling immunofluorescence, Western blot, co-immunoprecipitation, and electrophoretic mobility shift assay (EMSA) were also used to investigate the molecular mechanisms underlying the Sino-mediated anti-inflammatory effects in vivo and in vitro. Results Sino remarkably attenuated the cerebral infarction and neuronal apoptosis, reduced the levels of inflammatory cytokines, and alleviated neurological deficiency in MCAO mice. Sino significantly inhibited astrocytic activation and STAT3 phosphorylation as well as increased DRD2 and αB-crystallin (CRYAB) expression after MCAO. In vitro, Sino blocked OGD-induced activation of STAT3 and generation of pro-inflammatory cytokines in primary astrocytes, and these effects were significantly abolished by either DRD2 or CRYAB knockdown. Additionally, Sino induced up-regulation and nuclear translocation of CRYAB in astrocytes and enhanced the interaction between CRYAB and STAT3, which further inhibited the activation and DNA-binding activity of STAT3. Conclusions Our study demonstrates that Sino activates astrocytic DRD2 and thereby suppresses neuroinflammation via the CRYAB/STAT3 pathway, which sheds some light on a promising therapeutic strategy for ischemic stroke. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0739-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jing Qiu
- Department of Neurology, The General Hospital of Shenyang Military Region, Shenyang, Liaoning, 110016, People's Republic of China
| | - Zhongjun Yan
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, 710038, People's Republic of China
| | - Kai Tao
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, 710038, People's Republic of China
| | - Yansong Li
- Department of Neurology, The 463rd Hospital of PLA, Shenyang, Liaoning, 110042, People's Republic of China
| | - Yuqian Li
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, 710038, People's Republic of China
| | - Jingchen Li
- Department of Neurosurgery, The General Hospital of Shenyang Military Region, Shenyang, Liaoning, 110016, People's Republic of China
| | - Yushu Dong
- Department of Neurosurgery, The General Hospital of Shenyang Military Region, Shenyang, Liaoning, 110016, People's Republic of China
| | - Dayun Feng
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, 710038, People's Republic of China.
| | - Huisheng Chen
- Department of Neurology, The General Hospital of Shenyang Military Region, Shenyang, Liaoning, 110016, People's Republic of China.
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1024
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Iadecola C, Yaffe K, Biller J, Bratzke LC, Faraci FM, Gorelick PB, Gulati M, Kamel H, Knopman DS, Launer LJ, Saczynski JS, Seshadri S, Zeki Al Hazzouri A. Impact of Hypertension on Cognitive Function: A Scientific Statement From the American Heart Association. Hypertension 2016; 68:e67-e94. [PMID: 27977393 DOI: 10.1161/hyp.0000000000000053] [Citation(s) in RCA: 423] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Age-related dementia, most commonly caused by Alzheimer disease or cerebrovascular factors (vascular dementia), is a major public health threat. Chronic arterial hypertension is a well-established risk factor for both types of dementia, but the link between hypertension and its treatment and cognition remains poorly understood. In this scientific statement, a multidisciplinary team of experts examines the impact of hypertension on cognition to assess the state of the knowledge, to identify gaps, and to provide future directions. METHODS Authors with relevant expertise were selected to contribute to this statement in accordance with the American Heart Association conflict-of-interest management policy. Panel members were assigned topics relevant to their areas of expertise, reviewed the literature, and summarized the available data. RESULTS Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less clear. Observational studies demonstrated a cumulative effect of hypertension on cerebrovascular damage, but evidence from clinical trials that antihypertensive treatment improves cognition is not conclusive. CONCLUSIONS After carefully reviewing the literature, the group concluded that there were insufficient data to make evidence-based recommendations. However, judicious treatment of hypertension, taking into account goals of care and individual characteristics (eg, age and comorbidities), seems justified to safeguard vascular health and, as a consequence, brain health.
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1025
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Hawkins RA, Viña JR. How Glutamate Is Managed by the Blood-Brain Barrier. BIOLOGY 2016; 5:biology5040037. [PMID: 27740595 PMCID: PMC5192417 DOI: 10.3390/biology5040037] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/22/2016] [Indexed: 12/11/2022]
Abstract
A facilitative transport system exists on the blood–brain barrier (BBB) that has been tacitly assumed to be a path for glutamate entry to the brain. However, glutamate is a non-essential amino acid whose brain content is much greater than plasma, and studies in vivo show that glutamate does not enter the brain in appreciable quantities except in those small regions with fenestrated capillaries (circumventricular organs). The situation became understandable when luminal (blood facing) and abluminal (brain facing) membranes were isolated and studied separately. Facilitative transport of glutamate and glutamine exists only on the luminal membranes, whereas Na+-dependent transport systems for glutamate, glutamine, and some other amino acids are present only on the abluminal membrane. The Na+-dependent cotransporters of the abluminal membrane are in a position to actively transport amino acids from the extracellular fluid (ECF) into the endothelial cells of the BBB. These powerful secondary active transporters couple with the energy of the Na+-gradient to move glutamate and glutamine into endothelial cells, whereupon glutamate can exit to the blood on the luminal facilitative glutamate transporter. Glutamine may also exit the brain via separate facilitative transport system that exists on the luminal membranes, or glutamine can be hydrolyzed to glutamate within the BBB, thereby releasing ammonia that is freely diffusible. The γ-glutamyl cycle participates indirectly by producing oxoproline (pyroglutamate), which stimulates almost all secondary active transporters yet discovered in the abluminal membranes of the BBB.
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Affiliation(s)
- Richard A. Hawkins
- Department of Physiology and Biophysics, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60088, USA
- Correspondence: ; Tel.: +1-847-578-3218; Fax: +1-847-775-6510
| | - Juan R. Viña
- Department of Biochemistry and Molecular Biology, Faculty of Medicine and Odontology, Medical Research Institute-INCLIVA, University of Valencia, Valencia 46010, Spain;
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1026
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Wang ML, Li WB. Cognitive impairment after traumatic brain injury: The role of MRI and possible pathological basis. J Neurol Sci 2016; 370:244-250. [PMID: 27772768 DOI: 10.1016/j.jns.2016.09.049] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/01/2016] [Accepted: 09/23/2016] [Indexed: 01/26/2023]
Abstract
Traumatic brain injury (TBI) is closely related to increased incidence of cognitive impairment from the acute phase to chronic phase. At present, the pathological mechanism leading to cognitive impairment after TBI is still not fully understood. We hypothesize that neuron loss, diffuse axonal injury, microbleed, and blood-brain barrier (BBB) disruption altogether contribute to the development of cognitive impairment. Furthermore, the disruption of structural and functional neural network related to the cognitive function might bring about the final step in the occurrence of cognitive impairment after TBI. In this review, we summarize the role of different MRI techniques in the assessment of the pathological changes related to cognitive impairment after TBI. These MRI techniques include T1-MPRAGE sequence reflecting neuron loss, diffusion tensor imaging reflecting diffuse axonal injury, diffusion kurtosis imaging reflecting diffuse axonal injury and reactive gliosis, susceptibility weighted imaging showing microbleed, arterial spin labeling showing blood flow and dynamic contrast enhanced MRI showing BBB disruption. In the future, correlational study of multi-MRI sequences scan, pathological examination, and cognitive tests will provide valuable information for understanding the mechanism of cognitive impairment after TBI and manage TBI patients.
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Affiliation(s)
- Ming-Liang Wang
- Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Wen-Bin Li
- Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China; Imaging center, Kashgar Prefecture Second People(')s Hospital, Kashgar 844000, China.
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1027
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Jansson D, Scotter EL, Rustenhoven J, Coppieters N, Smyth LCD, Oldfield RL, Bergin PS, Mee EW, Graham ES, Faull RLM, Dragunow M. Interferon-γ blocks signalling through PDGFRβ in human brain pericytes. J Neuroinflammation 2016; 13:249. [PMID: 27654972 PMCID: PMC5031293 DOI: 10.1186/s12974-016-0722-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/13/2016] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Neuroinflammation and blood-brain barrier (BBB) disruption are common features of many brain disorders, including Alzheimer's disease, epilepsy, and motor neuron disease. Inflammation is thought to be a driver of BBB breakdown, but the underlying mechanisms for this are unclear. Brain pericytes are critical cells for maintaining the BBB and are immunologically active. We sought to test the hypothesis that inflammation regulates the BBB by altering pericyte biology. METHODS We exposed primary adult human brain pericytes to chronic interferon-gamma (IFNγ) for 4 days and measured associated functional aspects of pericyte biology. Specifically, we examined the influence of inflammation on platelet-derived growth factor receptor-beta (PDGFRβ) expression and signalling, as well as pericyte proliferation and migration by qRT-PCR, immunocytochemistry, flow cytometry, and western blotting. RESULTS Chronic IFNγ treatment had marked effects on pericyte biology most notably through the PDGFRβ, by enhancing agonist (PDGF-BB)-induced receptor phosphorylation, internalization, and subsequent degradation. Functionally, chronic IFNγ prevented PDGF-BB-mediated pericyte proliferation and migration. CONCLUSIONS Because PDGFRβ is critical for pericyte function and its removal leads to BBB leakage, our results pinpoint a mechanism linking chronic brain inflammation to BBB dysfunction.
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Affiliation(s)
- Deidre Jansson
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Gravida National Centre for Growth and Development, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Emma L Scotter
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Justin Rustenhoven
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Natacha Coppieters
- Department of Anatomy and Medical Imaging, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Leon C D Smyth
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | | | - Peter S Bergin
- Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand.,Auckland City Hospital, 1023, Auckland, New Zealand
| | - Edward W Mee
- Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand.,Auckland City Hospital, 1023, Auckland, New Zealand
| | - E Scott Graham
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Richard L M Faull
- Department of Anatomy and Medical Imaging, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Mike Dragunow
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand. .,Gravida National Centre for Growth and Development, The University of Auckland, 1023, Auckland, New Zealand. .,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand. .,Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, 1142, Auckland, New Zealand.
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1028
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Pardridge WM. Re-engineering therapeutic antibodies for Alzheimer’s disease as blood-brain barrier penetrating bi-specific antibodies. Expert Opin Biol Ther 2016; 16:1455-1468. [DOI: 10.1080/14712598.2016.1230195] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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1029
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Qosa H, Mohamed LA, Alqahtani S, Abuasal BS, Hill RA, Kaddoumi A. Transporters as Drug Targets in Neurological Diseases. Clin Pharmacol Ther 2016; 100:441-453. [PMID: 27447939 DOI: 10.1002/cpt.435] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/13/2016] [Accepted: 07/15/2016] [Indexed: 12/13/2022]
Abstract
Membrane transport proteins have central physiological function in maintaining cerebral homeostasis. These transporters are expressed in almost all cerebral cells in which they regulate the movement of a wide range of solutes, including endogenous substrates, xenobiotic, and therapeutic drugs. Altered activity/expression of central nervous system (CNS) transporters has been implicated in the onset and progression of multiple neurological diseases. Neurological diseases are heterogeneous diseases that involve complex pathological alterations with only a few treatment options; therefore, there is a great need for the development of novel therapeutic treatments. To that end, transporters have emerged recently to be promising therapeutic targets to halt or slow the course of neurological diseases. The objective of this review is to discuss implications of transporters in neurological diseases and summarize available evidence for targeting transporters as decent therapeutic approach in the treatment of neurological diseases.
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Affiliation(s)
- H Qosa
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana, USA
| | - L A Mohamed
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana, USA
| | - S Alqahtani
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana, USA
| | - B S Abuasal
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana, USA
| | - R A Hill
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana, USA
| | - A Kaddoumi
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana, USA.
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1030
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Curtis C, Zhang M, Liao R, Wood T, Nance E. Systems-level thinking for nanoparticle-mediated therapeutic delivery to neurological diseases. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2016; 9. [PMID: 27562224 DOI: 10.1002/wnan.1422] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/27/2016] [Accepted: 07/17/2016] [Indexed: 12/27/2022]
Abstract
Neurological diseases account for 13% of the global burden of disease. As a result, treating these diseases costs $750 billion a year. Nanotechnology, which consists of small (~1-100 nm) but highly tailorable platforms, can provide significant opportunities for improving therapeutic delivery to the brain. Nanoparticles can increase drug solubility, overcome the blood-brain and brain penetration barriers, and provide timed release of a drug at a site of interest. Many researchers have successfully used nanotechnology to overcome individual barriers to therapeutic delivery to the brain, yet no platform has translated into a standard of care for any neurological disease. The challenge in translating nanotechnology platforms into clinical use for patients with neurological disease necessitates a new approach to: (1) collect information from the fields associated with understanding and treating brain diseases and (2) apply that information using scalable technologies in a clinically-relevant way. This approach requires systems-level thinking to integrate an understanding of biological barriers to therapeutic intervention in the brain with the engineering of nanoparticle material properties to overcome those barriers. To demonstrate how a systems perspective can tackle the challenge of treating neurological diseases using nanotechnology, this review will first present physiological barriers to drug delivery in the brain and common neurological disease hallmarks that influence these barriers. We will then analyze the design of nanotechnology platforms in preclinical in vivo efficacy studies for treatment of neurological disease, and map concepts for the interaction of nanoparticle physicochemical properties and pathophysiological hallmarks in the brain. WIREs Nanomed Nanobiotechnol 2017, 9:e1422. doi: 10.1002/wnan.1422 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Chad Curtis
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
| | - Mengying Zhang
- Molecular Engineering and Sciences Institute, University of Washington, Seattle, WA, USA
| | - Rick Liao
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
| | - Thomas Wood
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Elizabeth Nance
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA.,Molecular Engineering and Sciences Institute, University of Washington, Seattle, WA, USA.,Department of Radiology, University of Washington, Seattle, WA, USA.,Center on Human Development and Disability, University of Washington, Seattle, WA, USA
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1031
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Abstract
Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and frontotemporal lobar dementia are among the most pressing problems of developed societies with aging populations. Neurons carry out essential functions such as signal transmission and network integration in the central nervous system and are the main targets of neurodegenerative disease. In this Review, I address how the neuron's environment also contributes to neurodegeneration. Maintaining an optimal milieu for neuronal function rests with supportive cells termed glia and the blood-brain barrier. Accumulating evidence suggests that neurodegeneration occurs in part because the environment is affected during disease in a cascade of processes collectively termed neuroinflammation. These observations indicate that therapies targeting glial cells might provide benefit for those afflicted by neurodegenerative disorders.
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1032
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The multifaceted role of metalloproteinases in physiological and pathological conditions in embryonic and adult brains. Prog Neurobiol 2016; 155:36-56. [PMID: 27530222 DOI: 10.1016/j.pneurobio.2016.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 07/10/2016] [Accepted: 08/08/2016] [Indexed: 02/07/2023]
Abstract
Matrix metalloproteinases (MMPs) are a large family of ubiquitous extracellular endopeptidases, which play important roles in a variety of physiological and pathological conditions, from the embryonic stages throughout adult life. Their extraordinary physiological "success" is due to concomitant broad substrate specificities and strict regulation of their expression, activation and inhibition levels. In recent years, MMPs have gained increasing attention as significant effectors in various aspects of central nervous system (CNS) physiology. Most importantly, they have been recognized as main players in a variety of brain disorders having different etiologies and evolution. A common aspect of these pathologies is the development of acute or chronic neuroinflammation. MMPs play an integral part in determining the result of neuroinflammation, in some cases turning its beneficial outcome into a harmful one. This review summarizes the most relevant studies concerning the physiology of MMPs, highlighting their involvement in both the developing and mature CNS, in long-lasting and acute brain diseases and, finally, in nervous system repair. Recently, a concerted effort has been made in identifying therapeutic strategies for major brain diseases by targeting MMP activities. However, from this revision of the literature appears clear that MMPs have multifaceted functional characteristics, which modulate physiological processes in multiple ways and with multiple consequences. Therefore, when choosing MMPs as possible targets, great care must be taken to evaluate the delicate balance between their activation and inhibition and to determine at which stage of the disease and at what level they become active in order maximize chances of success.
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1033
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Schmidt BZ, Lehmann M, Gutbier S, Nembo E, Noel S, Smirnova L, Forsby A, Hescheler J, Avci HX, Hartung T, Leist M, Kobolák J, Dinnyés A. In vitro acute and developmental neurotoxicity screening: an overview of cellular platforms and high-throughput technical possibilities. Arch Toxicol 2016; 91:1-33. [PMID: 27492622 DOI: 10.1007/s00204-016-1805-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 07/07/2016] [Indexed: 01/03/2023]
Abstract
Neurotoxicity and developmental neurotoxicity are important issues of chemical hazard assessment. Since the interpretation of animal data and their extrapolation to man is challenging, and the amount of substances with information gaps exceeds present animal testing capacities, there is a big demand for in vitro tests to provide initial information and to prioritize for further evaluation. During the last decade, many in vitro tests emerged. These are based on animal cells, human tumour cell lines, primary cells, immortalized cell lines, embryonic stem cells, or induced pluripotent stem cells. They differ in their read-outs and range from simple viability assays to complex functional endpoints such as neural crest cell migration. Monitoring of toxicological effects on differentiation often requires multiomics approaches, while the acute disturbance of neuronal functions may be analysed by assessing electrophysiological features. Extrapolation from in vitro data to humans requires a deep understanding of the test system biology, of the endpoints used, and of the applicability domains of the tests. Moreover, it is important that these be combined in the right way to assess toxicity. Therefore, knowledge on the advantages and disadvantages of all cellular platforms, endpoints, and analytical methods is essential when establishing in vitro test systems for different aspects of neurotoxicity. The elements of a test, and their evaluation, are discussed here in the context of comprehensive prediction of potential hazardous effects of a compound. We summarize the main cellular characteristics underlying neurotoxicity, present an overview of cellular platforms and read-out combinations assessing distinct parts of acute and developmental neurotoxicology, and highlight especially the use of stem cell-based test systems to close gaps in the available battery of tests.
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Affiliation(s)
- Béla Z Schmidt
- BioTalentum Ltd., Gödöllő, Hungary.,Stem Cell Biology and Embryology Unit, Department of Development and Regeneration, Stem Cell Institute Leuven, KU Leuven, Leuven, Belgium
| | - Martin Lehmann
- BioTalentum Ltd., Gödöllő, Hungary.,Institute of Neurophysiology and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Simon Gutbier
- Doerenkamp-Zbinden Chair for In Vitro Toxicology and Biomedicine, University of Konstanz, Constance, Germany
| | - Erastus Nembo
- BioTalentum Ltd., Gödöllő, Hungary.,Institute of Neurophysiology and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Sabrina Noel
- Louvain Centre for Toxicology and Applied Pharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Lena Smirnova
- Center for Alternatives to Animal Testing, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Anna Forsby
- Swedish Toxicology Research Center (Swetox), Södertälje, Sweden.,Department of Neurochemistry, Stockholm University, Stockholm, Sweden
| | - Jürgen Hescheler
- Institute of Neurophysiology and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Hasan X Avci
- BioTalentum Ltd., Gödöllő, Hungary.,Department of Medical Chemistry, University of Szeged, Szeged, Hungary
| | - Thomas Hartung
- Center for Alternatives to Animal Testing, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Marcel Leist
- Doerenkamp-Zbinden Chair for In Vitro Toxicology and Biomedicine, University of Konstanz, Constance, Germany
| | | | - András Dinnyés
- BioTalentum Ltd., Gödöllő, Hungary. .,Molecular Animal Biotechnology Laboratory, Szent István University, Gödöllő, 2100, Hungary.
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1034
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HIV-1 Tat Regulates Occludin and Aβ Transfer Receptor Expression in Brain Endothelial Cells via Rho/ROCK Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:4196572. [PMID: 27563375 PMCID: PMC4985576 DOI: 10.1155/2016/4196572] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/16/2016] [Accepted: 07/04/2016] [Indexed: 12/14/2022]
Abstract
HIV-1 transactivator protein (Tat) has been shown to play an important role in HIV-associated neurocognitive disorders. The aim of the present study was to evaluate the relationship between occludin and amyloid-beta (Aβ) transfer receptors in human cerebral microvascular endothelial cells (hCMEC/D3) in the context of HIV-1-related pathology. The protein expressions of occludin, receptor for advanced glycation end products (RAGE), and low-density lipoprotein receptor-related protein 1 (LRP1) in hCMEC/D3 cells were examined using western blotting and immunofluorescent staining. The mRNA levels of occludin, RAGE, and LRP1 were measured using quantitative real-time polymerase chain reaction. HIV-1 Tat at 1 µg/mL and the Rho inhibitor hydroxyfasudil (HF) at 30 µmol/L, with 24 h exposure, had no significant effect on hCMEC/D3 cell viability. Treatment with HIV-1 Tat protein decreased mRNA and protein levels of occludin and LRP1 and upregulated the expression of RAGE; however, these effects were attenuated by HF. These data suggest that the Rho/ROCK signaling pathway is involved in HIV-1 Tat-mediated changes in occludin, RAGE, and LRP1 in hCMEC/D3 cells. HF may have a beneficial influence by protecting the integrity of the blood-brain barrier and the expression of Aβ transfer receptors.
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1035
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Soulavie F, Sundaram MV. Auto-fusion and the shaping of neurons and tubes. Semin Cell Dev Biol 2016; 60:136-145. [PMID: 27436685 DOI: 10.1016/j.semcdb.2016.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/15/2016] [Accepted: 07/15/2016] [Indexed: 12/14/2022]
Abstract
Cells adopt specific shapes that are necessary for specific functions. For example, some neurons extend elaborate arborized dendrites that can contact multiple targets. Epithelial and endothelial cells can form tiny seamless unicellular tubes with an intracellular lumen. Recent advances showed that cells can auto-fuse to acquire those specific shapes. During auto-fusion, a cell merges two parts of its own plasma membrane. In contrast to cell-cell fusion or macropinocytic fission, which result in the merging or formation of two separate membrane bound compartments, auto-fusion preserves one compartment, but changes its shape. The discovery of auto-fusion in C. elegans was enabled by identification of specific protein fusogens, EFF-1 and AFF-1, that mediate cell-cell fusion. Phenotypic characterization of eff-1 and aff-1 mutants revealed that fusogen-mediated fusion of two parts of the same cell can be used to sculpt dendritic arbors, reconnect two parts of an axon after injury, or form a hollow unicellular tube. Similar auto-fusion events recently were detected in vertebrate cells, suggesting that auto-fusion could be a widely used mechanism for shaping neurons and tubes.
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Affiliation(s)
- Fabien Soulavie
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104,United States
| | - Meera V Sundaram
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104,United States.
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1036
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Lange C, Storkebaum E, de Almodóvar CR, Dewerchin M, Carmeliet P. Vascular endothelial growth factor: a neurovascular target in neurological diseases. Nat Rev Neurol 2016; 12:439-54. [PMID: 27364743 DOI: 10.1038/nrneurol.2016.88] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Brain function critically relies on blood vessels to supply oxygen and nutrients, to establish a barrier for neurotoxic substances, and to clear waste products. The archetypal vascular endothelial growth factor, VEGF, arose in evolution as a signal affecting neural cells, but was later co-opted by blood vessels to regulate vascular function. Consequently, VEGF represents an attractive target to modulate brain function at the neurovascular interface. On the one hand, VEGF is neuroprotective, through direct effects on neural cells and their progenitors and indirect effects on brain perfusion. In accordance, preclinical studies show beneficial effects of VEGF administration in neurodegenerative diseases, peripheral neuropathies and epilepsy. On the other hand, pathologically elevated VEGF levels enhance vessel permeability and leakage, and disrupt blood-brain barrier integrity, as in demyelinating diseases, for which blockade of VEGF may be beneficial. Here, we summarize current knowledge on the role and therapeutic potential of VEGF in neurological diseases.
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Affiliation(s)
- Christian Lange
- Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center, Department of Oncology (KU Leuven) and Vesalius Research Center (VIB), Campus Gasthuisberg O&N4, Herestraat 49 - 912, B-3000, Leuven, Belgium
| | - Erik Storkebaum
- Molecular Neurogenetics Laboratory, Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, D-48149 Muenster, Germany.,Faculty of Medicine, University of Muenster, Roentgenstrasse 20, D-48149 Muenster, Germany
| | | | - Mieke Dewerchin
- Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center, Department of Oncology (KU Leuven) and Vesalius Research Center (VIB), Campus Gasthuisberg O&N4, Herestraat 49 - 912, B-3000, Leuven, Belgium
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center, Department of Oncology (KU Leuven) and Vesalius Research Center (VIB), Campus Gasthuisberg O&N4, Herestraat 49 - 912, B-3000, Leuven, Belgium
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1037
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Abstract
PURPOSE OF REVIEW This article evaluates recent experimental and human evidence regarding the involvement of lipids, lipoproteins, and apolipoproteins in neurodegenerative diseases, and reviews the current literature of the effects of cholesterol-lowering treatment on cognition. RECENT FINDINGS Plasma levels of traditional lipids and lipoproteins are not consistently associated with risk of dementia even though low plasma levels of apolipoprotein E, through unknown mechanisms, robustly predict future dementia. Experimental evidence suggests neuroprotective roles of several brain and cerebrospinal fluid apolipoproteins. Whether plasma levels of apolipoprotein E, or any other apolipoprotein with possible central nervous system and/or blood-brain barrier functions (apolipoproteins J, A-I, A-II, A-IV, D, C-I, and C-III) may become accessible biomarker components that improve risk prediction for dementia together with genetic risk variants and cardiovascular risk factors remains to be determined. SUMMARY Apolipoproteins with well established functions in peripheral lipid metabolism may play important roles for brain vascular health and Alzheimer's disease pathophysiology. Experimental work on lipids, lipoproteins, and apolipoproteins in the central nervous system together with robust prospective human studies will help to substantiate the drug target potential of these lipid components.
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Affiliation(s)
- Cheryl L Wellington
- aDepartment of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada bDepartment of Clinical Biochemistry, Rigshospitalet, Copenhagen University Hospitals cFaculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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1038
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Khan AT, Dobson RJB, Sattlecker M, Kiddle SJ. Alzheimer's disease: are blood and brain markers related? A systematic review. Ann Clin Transl Neurol 2016; 3:455-62. [PMID: 27547773 PMCID: PMC4891999 DOI: 10.1002/acn3.313] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/29/2016] [Accepted: 04/07/2016] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Peripheral protein biomarkers of Alzheimer's disease (AD) may help identify novel treatment avenues by allowing early diagnosis, recruitment to clinical trials, and treatment initiation. The purpose of this review was to determine which proteins have been found to be differentially expressed in the AD brain and whether these proteins are also found within the blood of AD patients. METHODS A two-stage approach was conducted. The first stage involved conducting a systematic search to identify discovery-based brain proteomic studies of AD. The second stage involved comparing whether proteins found to be differentially expressed in AD brain were also differentially expressed in the blood. RESULTS Across 11 discovery based brain proteomic studies 371 proteins were at different levels in the AD brain. Nine proteins were frequently found, defined as appearing in at least three separate studies. Of these proteins heat-shock cognate 71 kDa, ubiquitin carboxyl-terminal hydrolase isozyme L1, and 2',3'-cyclic nucleotide 3' phosphodiesterase alone were found to share a consistent direction of change, being consistently upregulated in studies they appeared in. Eighteen proteins seen as being differentially expressed within the AD brain were present in blood proteomic studies of AD. Only complement C4a was seen multiple times within both the blood and brain proteomic studies. INTERPRETATION We report a number of proteins appearing in both the blood and brain of AD patients. Of these proteins, C4a may be a good candidate for further follow-up in large-scale replication efforts.
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Affiliation(s)
- Ali T. Khan
- GKT School of Medical EducationKing's College LondonLondonUnited Kingdom
| | - Richard J. B. Dobson
- MRC Social, Genetic and Developmental Psychiatry CentreInstitute of Psychiatry, Psychology and NeuroscienceKing's College LondonLondonUnited Kingdom
- NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for DementiaLondonUnited Kingdom
| | - Martina Sattlecker
- MRC Social, Genetic and Developmental Psychiatry CentreInstitute of Psychiatry, Psychology and NeuroscienceKing's College LondonLondonUnited Kingdom
- NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for DementiaLondonUnited Kingdom
| | - Steven J. Kiddle
- MRC Social, Genetic and Developmental Psychiatry CentreInstitute of Psychiatry, Psychology and NeuroscienceKing's College LondonLondonUnited Kingdom
- NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for DementiaLondonUnited Kingdom
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1039
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Lack of CAR impacts neuronal function and cerebrovascular integrity in vivo. Exp Neurol 2016; 283:39-48. [PMID: 27240521 DOI: 10.1016/j.expneurol.2016.05.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/13/2016] [Accepted: 05/12/2016] [Indexed: 12/12/2022]
Abstract
Nuclear receptors (NRs) are a group of transcription factors emerging as players in normal and pathological CNS development. Clinically, an association between the constitutive androstane NR (CAR) and cognitive impairment was proposed, however never experimentally investigated. We wished to test the hypothesis that the impact of CAR on neurophysiology and behavior is underlined by cerebrovascular-neuronal modifications. We have used CAR(-/-) C57BL/6 and wild type mice and performed a battery of behavioral tests (recognition, memory, motor coordination, learning and anxiety) as well as longitudinal video-electroencephalographic recordings (EEG). Brain cell morphology was assessed using 2-photon or electron microscopy and fluorescent immunohistochemistry. We observed recognition memory impairment and increased anxiety-like behavior in CAR(-/-) mice, while locomotor activity was not affected. Concomitantly to memory deficits, EEG monitoring revealed a decrease in 3.5-7Hz waves during the awake/exploration and sleep periods. Behavioral and EEG abnormalities in CAR(-/-) mice mirrored structural changes, including tortuous fronto-parietal penetrating vessels. At the cellular level we found reduced ZO-1, but not CLDN5, tight junction protein expression in cortical and hippocampal isolated microvessel preparations. Interestingly, the neurotoxin kainic acid, when injected peripherally, provoked a rapid onset of generalized convulsions in CAR(-/-) as compared to WT mice, supporting the hypothesis of vascular permeability. The morphological phenotype of CAR(-/-) mice also included some modifications of GFAP/IBA1 glial cells in the parenchymal or adjacent to collagen-IV(+) or FITC(+) microvessels. Neuronal defects were also observed including increased cortical NEUN(+) cell density, hippocampal granule cell dispersion and increased NPY immunoreactivity in the CA1 region in CAR(-/-) mice. The latter may contribute to the in vivo phenotype. Our results indicate that behavioral and electroencephalographic changes in adult CAR(-/-) mice are concomitant to discrete developmental or structural brain defects. The latter could increase the vulnerability to neurotoxins. The possibility that interfering with nuclear receptors during development could contribute to adulthood brain changes is proposed.
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1040
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Nelson AR, Sweeney MD, Sagare AP, Zlokovic BV. Neurovascular dysfunction and neurodegeneration in dementia and Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1862:887-900. [PMID: 26705676 PMCID: PMC4821735 DOI: 10.1016/j.bbadis.2015.12.016] [Citation(s) in RCA: 360] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/10/2015] [Accepted: 12/10/2015] [Indexed: 02/07/2023]
Abstract
Vascular insults can initiate a cascade of molecular events leading to neurodegeneration, cognitive impairment, and dementia. Here, we review the cellular and molecular mechanisms in cerebral blood vessels and the pathophysiological events leading to cerebral blood flow dysregulation and disruption of the neurovascular unit and the blood-brain barrier, which all may contribute to the onset and progression of dementia and Alzheimer's disease (AD). Particularly, we examine the link between neurovascular dysfunction and neurodegeneration including the effects of AD genetic risk factors on cerebrovascular functions and clearance of Alzheimer's amyloid-β peptide toxin, and the impact of vascular risk factors, environment, and lifestyle on cerebral blood vessels, which in turn may affect synaptic, neuronal, and cognitive functions. Finally, we examine potential experimental treatments for dementia and AD based on the neurovascular model, and discuss some critical questions to be addressed by future studies. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.
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Affiliation(s)
- Amy R Nelson
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Melanie D Sweeney
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Abhay P Sagare
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA.
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1041
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Grabrucker AM, Ruozi B, Belletti D, Pederzoli F, Forni F, Vandelli MA, Tosi G. Nanoparticle transport across the blood brain barrier. Tissue Barriers 2016; 4:e1153568. [PMID: 27141426 DOI: 10.1080/21688370.2016.1153568] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/02/2016] [Accepted: 02/04/2016] [Indexed: 01/13/2023] Open
Abstract
While the role of the blood-brain barrier (BBB) is increasingly recognized in the (development of treatments targeting neurodegenerative disorders, to date, few strategies exist that enable drug delivery of non-BBB crossing molecules directly to their site of action, the brain. However, the recent advent of Nanomedicines may provide a potent tool to implement CNS targeted delivery of active compounds. Approaches for BBB crossing are deeply investigated in relation to the pathology: among the main important diseases of the CNS, this review focuses on the application of nanomedicines to neurodegenerative disorders (Alzheimer, Parkinson and Huntington's Disease) and to other brain pathologies as epilepsy, infectious diseases, multiple sclerosis, lysosomal storage disorders, strokes.
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Affiliation(s)
- Andreas M Grabrucker
- WG Molecular Analysis of Synaptopathies, Neurology Dept, Neurocenter of Ulm University , Ulm, Germany
| | - Barbara Ruozi
- Pharmaceutical Technology, Te.Far.T.I. Group, Department of Life Sciences, University of Modena and Reggio Emilia ; Modena, Italy
| | - Daniela Belletti
- Pharmaceutical Technology, Te.Far.T.I. Group, Department of Life Sciences, University of Modena and Reggio Emilia ; Modena, Italy
| | - Francesca Pederzoli
- Pharmaceutical Technology, Te.Far.T.I. Group, Department of Life Sciences, University of Modena and Reggio Emilia ; Modena, Italy
| | - Flavio Forni
- Pharmaceutical Technology, Te.Far.T.I. Group, Department of Life Sciences, University of Modena and Reggio Emilia ; Modena, Italy
| | - Maria Angela Vandelli
- Pharmaceutical Technology, Te.Far.T.I. Group, Department of Life Sciences, University of Modena and Reggio Emilia ; Modena, Italy
| | - Giovanni Tosi
- Pharmaceutical Technology, Te.Far.T.I. Group, Department of Life Sciences, University of Modena and Reggio Emilia ; Modena, Italy
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1042
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Cutforth T, DeMille MM, Agalliu I, Agalliu D. CNS autoimmune disease after Streptococcus pyogenes infections: animal models, cellular mechanisms and genetic factors. FUTURE NEUROLOGY 2016; 11:63-76. [PMID: 27110222 DOI: 10.2217/fnl.16.4] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Streptococcus pyogenes infections have been associated with two autoimmune diseases of the CNS: Sydenham's chorea (SC) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infections (PANDAS). Despite the high frequency of pharyngeal streptococcus infections among children, only a small fraction develops SC or PANDAS. This suggests that several factors in combination are necessary to trigger autoimmune complications: specific S. pyogenes strains that induce a strong immune response toward the host nervous system; genetic susceptibility that predispose children toward an autoimmune response involving movement or tic symptoms; and multiple infections of the throat or tonsils that lead to a robust Th17 cellular and humoral immune response when untreated. In this review, we summarize the evidence for each factor and propose that all must be met for the requisite neurovascular pathology and behavioral deficits found in SC/PANDAS.
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Affiliation(s)
- Tyler Cutforth
- Department of Neurology, Columbia University Medical Center, 650 West 168 Street, Room 310E, New York, NY 10032, USA
| | - Mellissa Mc DeMille
- Department of Pediatrics, Yale Child Health Research Center, Yale University School of Medicine, 464 Congress Avenue, Suite S208, New Haven, CT 06519, USA
| | - Ilir Agalliu
- Department of Epidemiology & Population Health, Albert Einstein College of Medicine, 1300 Morris Park Ave., Room 1315-B, Bronx, NY 10461, USA
| | - Dritan Agalliu
- Department of Neurology, Columbia University Medical Center, 650 West 168 Street, Room 310E, New York, NY 10032, USA; Departments of Pathology & Cell Biology & Pharmacology, Columbia University Medical Center, 650 West 168 Street, Room 310E, New York, NY 10032, USA
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