101
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Saeger HN, Olson DE. Psychedelic-inspired approaches for treating neurodegenerative disorders. J Neurochem 2021; 162:109-127. [PMID: 34816433 DOI: 10.1111/jnc.15544] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/19/2021] [Accepted: 11/21/2021] [Indexed: 12/21/2022]
Abstract
Psychedelics are increasingly being recognized for their potential to treat a wide range of brain disorders including depression, post-traumatic stress disorder (PTSD), and substance use disorder. Their broad therapeutic potential might result from an ability to rescue cortical atrophy common to many neuropsychiatric and neurodegenerative diseases by impacting neurotrophic factor gene expression, activating neuronal growth and survival mechanisms, and modulating the immune system. While the therapeutic potential of psychedelics has not yet been extended to neurodegenerative disorders, we provide evidence suggesting that approaches based on psychedelic science might prove useful for treating these diseases. The primary target of psychedelics, the 5-HT2A receptor, plays key roles in cortical neuron health and is dysregulated in Alzheimer's disease. Moreover, evidence suggests that psychedelics and related compounds could prove useful for treating the behavioral and psychological symptoms of dementia (BPSD). While more research is needed to probe the effects of psychedelics in models of neurodegenerative diseases, the robust effects of these compounds on structural and functional neuroplasticity and inflammation clearly warrant further investigation.
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Affiliation(s)
- Hannah N Saeger
- Pharmacology and Toxicology Graduate Group, University of California, Davis, Davis, California, USA
| | - David E Olson
- Department of Chemistry, University of California, Davis, Davis, California, USA.,Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, California, USA.,Center for Neuroscience, University of California, Davis, Davis, California, USA
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102
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Fairless R, Bading H, Diem R. Pathophysiological Ionotropic Glutamate Signalling in Neuroinflammatory Disease as a Therapeutic Target. Front Neurosci 2021; 15:741280. [PMID: 34744612 PMCID: PMC8567076 DOI: 10.3389/fnins.2021.741280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/30/2021] [Indexed: 01/15/2023] Open
Abstract
Glutamate signalling is an essential aspect of neuronal communication involving many different glutamate receptors, and underlies the processes of memory, learning and synaptic plasticity. Despite neuroinflammatory diseases covering a range of maladies with very different biological causes and pathophysiologies, a central role for dysfunctional glutamate signalling is becoming apparent. This is not just restricted to the well-described role of glutamate in mediating neurodegeneration, but also includes a myriad of other influences that glutamate can exert on the vasculature, as well as immune cell and glial regulation, reflecting the ability of neurons to communicate with these compartments in order to couple their activity with neuronal requirements. Here, we discuss the role of pathophysiological glutamate signalling in neuroinflammatory disease, using both multiple sclerosis and Alzheimer's disease as examples, and how current steps are being made to harness our growing understanding of these processes in the development of neuroprotective strategies. This review focuses in particular on N-methyl-D-aspartate (NMDA) and 2-amino-3-(3-hydroxy-5-methylisooxazol-4-yl) propionate (AMPA) type ionotropic glutamate receptors, although metabotropic, G-protein-coupled glutamate receptors may also contribute to neuroinflammatory processes. Given the indispensable roles of glutamate-gated ion channels in synaptic communication, means of pharmacologically distinguishing between physiological and pathophysiological actions of glutamate will be discussed that allow deleterious signalling to be inhibited whilst minimising the disturbance of essential neuronal function.
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Affiliation(s)
- Richard Fairless
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
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103
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Gilbert A, Elorza-Vidal X, Rancillac A, Chagnot A, Yetim M, Hingot V, Deffieux T, Boulay AC, Alvear-Perez R, Cisternino S, Martin S, Taïb S, Gelot A, Mignon V, Favier M, Brunet I, Declèves X, Tanter M, Estevez R, Vivien D, Saubaméa B, Cohen-Salmon M. Megalencephalic leukoencephalopathy with subcortical cysts is a developmental disorder of the gliovascular unit. eLife 2021; 10:71379. [PMID: 34723793 PMCID: PMC8598235 DOI: 10.7554/elife.71379] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/27/2021] [Indexed: 12/20/2022] Open
Abstract
Absence of the astrocyte-specific membrane protein MLC1 is responsible for megalencephalic leukoencephalopathy with subcortical cysts (MLC), a rare type of leukodystrophy characterized by early-onset macrocephaly and progressive white matter vacuolation that lead to ataxia, spasticity, and cognitive decline. During postnatal development (from P5 to P15 in the mouse), MLC1 forms a membrane complex with GlialCAM (another astrocytic transmembrane protein) at the junctions between perivascular astrocytic processes. Perivascular astrocytic processes along with blood vessels form the gliovascular unit. It was not previously known how MLC1 influences the physiology of the gliovascular unit. Here, using the Mlc1 knock-out mouse model of MLC, we demonstrated that MLC1 controls the postnatal development and organization of perivascular astrocytic processes, vascular smooth muscle cell contractility, neurovascular coupling, and intraparenchymal interstitial fluid clearance. Our data suggest that MLC is a developmental disorder of the gliovascular unit, and perivascular astrocytic processes and vascular smooth muscle cell maturation defects are primary events in the pathogenesis of MLC and therapeutic targets for this disease.
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Affiliation(s)
- Alice Gilbert
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Research in Biology (CIRB), College de France, CNRS, Paris, France.,École doctorale Cerveau Cognition Comportement "ED3C" N°158, Pierre and Marie Curie University, Paris, France
| | - Xabier Elorza-Vidal
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Research in Biology (CIRB), College de France, CNRS, Paris, France
| | - Armelle Rancillac
- Neuroglial Interactions in Cerebral Physiopathology Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, Labex Memolife, Université PSL, Paris, France
| | - Audrey Chagnot
- Normandie University, UNICAEN, INSERM, GIP Cyceron, Institut Blood and Brain, Physiopathology and Imaging of Neurological Disorders, Caen, France
| | - Mervé Yetim
- Normandie University, UNICAEN, INSERM, GIP Cyceron, Institut Blood and Brain, Physiopathology and Imaging of Neurological Disorders, Caen, France
| | - Vincent Hingot
- Physics for Medicine Paris, ESPCI Paris, PSL University, Paris, France
| | - Thomas Deffieux
- Physics for Medicine Paris, ESPCI Paris, PSL University, Paris, France
| | - Anne-Cécile Boulay
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Research in Biology (CIRB), College de France, CNRS, Paris, France
| | - Rodrigo Alvear-Perez
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Research in Biology (CIRB), College de France, CNRS, Paris, France
| | | | - Sabrina Martin
- Molecular Control of the Neurovascular Development Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, Labex Memolife, Université PSL, Paris, France
| | - Sonia Taïb
- Molecular Control of the Neurovascular Development Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, Labex Memolife, Université PSL, Paris, France
| | - Aontoinette Gelot
- Service d'anatomie et cytologie pathologie de l'hôpital Armand Trousseau, Paris, France
| | - Virginie Mignon
- Cellular and Molecular Imaging Facility, US25 INSERM, UMS3612 CNRS, Faculty of Pharmacy, University of Paris, Paris, France
| | | | - Isabelle Brunet
- Molecular Control of the Neurovascular Development Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, Labex Memolife, Université PSL, Paris, France
| | - Xavier Declèves
- Université de Paris, Faculté de Santé, Paris, France.,Biologie du médicament et toxicologie, Assistance Publique - hôpitaux de Paris, APHP, Hôpital Cochin, Paris, France
| | - Mickael Tanter
- Physics for Medicine Paris, ESPCI Paris, PSL University, Paris, France
| | - Raul Estevez
- Unitat de Fisiología, Departament de Ciències Fisiològiques, IDIBELL-Institute of Neurosciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.,Centro de Investigación en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Denis Vivien
- Normandie University, UNICAEN, INSERM, GIP Cyceron, Institut Blood and Brain, Physiopathology and Imaging of Neurological Disorders, Caen, France
| | - Bruno Saubaméa
- Université de Paris, Faculté de Santé, Paris, France.,Cellular and Molecular Imaging Facility, US25 INSERM, UMS3612 CNRS, Faculty of Pharmacy, University of Paris, Paris, France
| | - Martine Cohen-Salmon
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Research in Biology (CIRB), College de France, CNRS, Paris, France
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104
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Lan G, Wang P, Chan RB, Liu Z, Yu Z, Liu X, Yang Y, Zhang J. Astrocytic VEGFA: An essential mediator in blood-brain-barrier disruption in Parkinson's disease. Glia 2021; 70:337-353. [PMID: 34713920 DOI: 10.1002/glia.24109] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/13/2021] [Accepted: 10/11/2021] [Indexed: 12/29/2022]
Abstract
The integrity of blood-brain-barrier (BBB) is essential for normal brain functions, synaptic remodeling, and angiogenesis. BBB disruption is a common pathology during Parkinson's disease (PD), and has been hypothesized to contribute to the progression of PD. However, the molecular mechanism of BBB disruption in PD needs further investigation. Here, A53T PD mouse and a 3-cell type in vitro BBB model were used to study the roles of α-synuclein (α-syn) in BBB disruption with the key results confirmed in the brains of PD patients obtained at autopsy. The A53T PD mouse studies showed that the expression of tight junction-related proteins decreased, along with increased vascular permeability and accumulation of oligomeric α-syn in activated astrocytes in the brain. The in vitro BBB model studies demonstrated that treatment with oligomeric α-syn, but not monomeric or fibrillar α-syn, resulted in significant disruption of BBB integrity. This process involved the expression and release of vascular endothelial growth factor A (VEGFA) and nitric oxide (NO) from oligomeric α-syn treated astrocytes. Increased levels of VEGFA and iNOS were also observed in the brain of PD patients. Blocking the VEGFA signaling pathway in the in vitro BBB model effectively protected the barrier against the harmful effects of oligomeric α-syn. Finally, the protective effects on BBB integrity associated with inhibition of VEGFA signaling pathway was also confirmed in PD mice. Taken together, our study concluded that oligomeric α-syn is critically involved in PD-associated BBB disruption, in a process that is mediated by astrocyte-derived VEGFA.
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Affiliation(s)
- Guoyu Lan
- Department of Pathology, Peking University Health Science Center, Beijing, China
| | - Pan Wang
- Department of Pathology, Zhejiang University First Affiliated Hospital and School of Medicine, Hangzhou, Zhejiang, China.,National Health and Disease Human Brain Tissue Resource Center, Zhejiang University, Hangzhou, Zhejiang, China
| | | | - Zongran Liu
- Department of Pathology, Peking University Health Science Center, Beijing, China
| | - Zhenwei Yu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Xiaodan Liu
- Department of Pathology, Peking University Health Science Center, Beijing, China
| | - Ying Yang
- Department of Pathology, Peking University Health Science Center, Beijing, China
| | - Jing Zhang
- Department of Pathology, Zhejiang University First Affiliated Hospital and School of Medicine, Hangzhou, Zhejiang, China.,National Health and Disease Human Brain Tissue Resource Center, Zhejiang University, Hangzhou, Zhejiang, China
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105
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Becchi S, Buson A, Balleine BW. Inhibition of vascular adhesion protein 1 protects dopamine neurons from the effects of acute inflammation and restores habit learning in the striatum. J Neuroinflammation 2021; 18:233. [PMID: 34654450 PMCID: PMC8520223 DOI: 10.1186/s12974-021-02288-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/04/2021] [Indexed: 12/17/2022] Open
Abstract
Background Changes in dopaminergic neural function can be induced by an acute inflammatory state that, by altering the integrity of the neurovasculature, induces neuronal stress, cell death and causes functional deficits. Effectively blocking these effects of inflammation could, therefore, reduce both neuronal and functional decline. To test this hypothesis, we inhibited vascular adhesion protein 1 (VAP-1), a membrane-bound protein expressed on the endothelial cell surface, that mediates leukocyte extravasation and induces oxidative stress. Method We induced dopaminergic neuronal loss by infusing lipopolysaccharide (LPS) directly into the substantia nigra (SN) in rats and administered the VAP-1 inhibitor, PXS-4681A, daily. Results LPS produced: an acute inflammatory response, the loss of dopaminergic neurons in the SN, reduced the dopaminergic projection to SN target regions, particularly the dorsolateral striatum (DLS), and a deficit in habit learning, a key function of the DLS. In an attempt to protect SN neurons from this inflammatory response we found that VAP-1 inhibition not only reduced neutrophil infiltration in the SN and striatum, but also reduced the associated striatal microglia and astrocyte response. We found VAP-1 inhibition protected dopamine neurons in the SN, their projections to the striatum and promoted the functional recovery of habit learning. Thus, we reversed the loss of habitual actions, a function usually dependent on dopamine release in DLS and sensitive to striatal dysfunction. Conclusions We establish, therefore, that VAP-1 inhibition has an anti-inflammatory profile that may be beneficial in the treatment of dopamine neuron dysfunction caused by an acute inflammatory state in the brain. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02288-8.
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Affiliation(s)
- Serena Becchi
- Decision Neuroscience Lab, School of Psychology, UNSW Sydney, Randwick, NSW, 2052, Australia
| | | | - Bernard W Balleine
- Decision Neuroscience Lab, School of Psychology, UNSW Sydney, Randwick, NSW, 2052, Australia.
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106
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Neuroinflammatory astrocyte subtypes in the mouse brain. Nat Neurosci 2021; 24:1475-1487. [PMID: 34413515 DOI: 10.1038/s41593-021-00905-6] [Citation(s) in RCA: 260] [Impact Index Per Article: 86.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/08/2021] [Indexed: 02/07/2023]
Abstract
Astrocytes undergo an inflammatory transition after infections, acute injuries and chronic neurodegenerative diseases. How this transition is affected by time and sex, its heterogeneity at the single-cell level and how sub-states are spatially distributed in the brain remains unclear. In this study, we investigated transcriptome changes of mouse cortical astrocytes after an acute inflammatory stimulus using the bacterial cell wall endotoxin lipopolysaccharide. We identified fast transcriptomic changes in astrocytes occurring within hours that drastically change over time. By sequencing ~80,000 astrocytes at single-cell resolution, we show that inflammation causes a widespread response with subtypes of astrocytes undergoing distinct inflammatory transitions with defined transcriptomic profiles. We also attribute key sub-states of inflammation-induced reactive astrocytes to specific brain regions using spatial transcriptomics and in situ hybridization. Together, our datasets provide a powerful resource for profiling astrocyte heterogeneity and will be useful for understanding the biological importance of regionally constrained reactive astrocyte sub-states.
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107
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Weiss S, Clamon LC, Manoim JE, Ormerod KG, Parnas M, Littleton JT. Glial ER and GAP junction mediated Ca 2+ waves are crucial to maintain normal brain excitability. Glia 2021; 70:123-144. [PMID: 34528727 DOI: 10.1002/glia.24092] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 11/08/2022]
Abstract
Astrocytes play key roles in regulating multiple aspects of neuronal function from invertebrates to humans and display Ca2+ fluctuations that are heterogeneously distributed throughout different cellular microdomains. Changes in Ca2+ dynamics represent a key mechanism for how astrocytes modulate neuronal activity. An unresolved issue is the origin and contribution of specific glial Ca2+ signaling components at distinct astrocytic domains to neuronal physiology and brain function. The Drosophila model system offers a simple nervous system that is highly amenable to cell-specific genetic manipulations to characterize the role of glial Ca2+ signaling. Here we identify a role for ER store-operated Ca2+ entry (SOCE) pathway in perineurial glia (PG), a glial population that contributes to the Drosophila blood-brain barrier. We show that PG cells display diverse Ca2+ activity that varies based on their locale within the brain. Ca2+ signaling in PG cells does not require extracellular Ca2+ and is blocked by inhibition of SOCE, Ryanodine receptors, or gap junctions. Disruption of these components triggers stimuli-induced seizure-like episodes. These findings indicate that Ca2+ release from internal stores and its propagation between neighboring glial cells via gap junctions are essential for maintaining normal nervous system function.
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Affiliation(s)
- Shirley Weiss
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lauren C Clamon
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Julia E Manoim
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kiel G Ormerod
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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108
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Chen S, Shao L, Ma L. Cerebral Edema Formation After Stroke: Emphasis on Blood-Brain Barrier and the Lymphatic Drainage System of the Brain. Front Cell Neurosci 2021; 15:716825. [PMID: 34483842 PMCID: PMC8415457 DOI: 10.3389/fncel.2021.716825] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 07/20/2021] [Indexed: 01/01/2023] Open
Abstract
Brain edema is a severe stroke complication that is associated with prolonged hospitalization and poor outcomes. Swollen tissues in the brain compromise cerebral perfusion and may also result in transtentorial herniation. As a physical and biochemical barrier between the peripheral circulation and the central nervous system (CNS), the blood–brain barrier (BBB) plays a vital role in maintaining the stable microenvironment of the CNS. Under pathological conditions, such as ischemic stroke, the dysfunction of the BBB results in increased paracellular permeability, directly contributing to the extravasation of blood components into the brain and causing cerebral vasogenic edema. Recent studies have led to the discovery of the glymphatic system and meningeal lymphatic vessels, which provide a channel for cerebrospinal fluid (CSF) to enter the brain and drain to nearby lymph nodes and communicate with the peripheral immune system, modulating immune surveillance and brain responses. A deeper understanding of the function of the cerebral lymphatic system calls into question the known mechanisms of cerebral edema after stroke. In this review, we first discuss how BBB disruption after stroke can cause or contribute to cerebral edema from the perspective of molecular and cellular pathophysiology. Finally, we discuss how the cerebral lymphatic system participates in the formation of cerebral edema after stroke and summarize the pathophysiological process of cerebral edema formation after stroke from the two directions of the BBB and cerebral lymphatic system.
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Affiliation(s)
- Sichao Chen
- Department of Neurosurgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Linqian Shao
- Department of Neurosurgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Li Ma
- Department of Neurosurgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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109
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Ullah R, Rauf N, Nabi G, Yi S, Yu-Dong Z, Fu J. Mechanistic insight into high-fat diet-induced metabolic inflammation in the arcuate nucleus of the hypothalamus. Biomed Pharmacother 2021; 142:112012. [PMID: 34388531 DOI: 10.1016/j.biopha.2021.112012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/31/2021] [Accepted: 08/03/2021] [Indexed: 12/16/2022] Open
Abstract
A high-fat diet (HFD) is linked with cytokines production by non-neuronal cells within the hypothalamus, which mediates metabolic inflammation. These cytokines then activate different inflammatory mediators in the arcuate nucleus of the hypothalamus (ARC), a primary hypothalamic area accommodating proopiomelanocortin (POMC) and agouti-related peptide (AGRP) neurons, first-order neurons that sense and integrate peripheral metabolic signals and then respond accordingly. These mediators, such as inhibitor of κB kinase-β (IKKβ), suppression of cytokine signaling 3 (SOCS3), c-Jun N-terminal kinases (JNKs), protein kinase C (PKC), etc., cause insulin and leptin resistance in POMC and AGRP neurons and support obesity and related metabolic complications. On the other hand, inhibition of these mediators has been shown to counteract the impaired metabolism. Therefore, it is important to discuss the contribution of neuronal and non-neuronal cells in HFD-induced hypothalamic inflammation. Furthermore, understanding few other questions, such as the diets causing hypothalamic inflammation, the gender disparity in response to HFD feeding, and how hypothalamic inflammation affects ARC neurons to cause impaired metabolism, will be helpful for the development of therapeutic approaches to prevent or treat HFD-induced obesity.
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Affiliation(s)
- Rahim Ullah
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310052, China; Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Naveed Rauf
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310052, China
| | - Ghulam Nabi
- Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, Hebei Province, China; Department of Life Sciences, School of Science, University of Management and Technology (UMT), Lahore, Pakistan
| | - Shen Yi
- Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.
| | - Zhou Yu-Dong
- Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.
| | - Junfen Fu
- Department of Endocrinology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310052, China; National Clinical Research Center for Child Health, Hangzhou 310052, China; National Children's Regional Medical Center, Hangzhou 310052, China.
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110
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Sharma RK, Calderon C, Vivas-Mejia PE. Targeting Non-coding RNA for Glioblastoma Therapy: The Challenge of Overcomes the Blood-Brain Barrier. FRONTIERS IN MEDICAL TECHNOLOGY 2021; 3:678593. [PMID: 35047931 PMCID: PMC8757885 DOI: 10.3389/fmedt.2021.678593] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/16/2021] [Indexed: 12/12/2022] Open
Abstract
Glioblastoma (GBM) is the most malignant form of all primary brain tumors, and it is responsible for around 200,000 deaths each year worldwide. The standard therapy for GBM treatment includes surgical resection followed by temozolomide-based chemotherapy and/or radiotherapy. With this treatment, the median survival rate of GBM patients is only 15 months after its initial diagnosis. Therefore, novel and better treatment modalities for GBM treatment are urgently needed. Mounting evidence indicates that non-coding RNAs (ncRNAs) have critical roles as regulators of gene expression. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are among the most studied ncRNAs in health and disease. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Several dysregulated miRNAs and lncRNAs have been identified in GBM cell lines and GBM tumor samples. Some of them have been proposed as diagnostic and prognostic markers, and as targets for GBM treatment. Most ncRNA-based therapies use oligonucleotide RNA molecules which are normally of short life in circulation. Nanoparticles (NPs) have been designed to increase the half-life of oligonucleotide RNAs. An additional challenge faced not only by RNA oligonucleotides but for therapies designed for brain-related conditions, is the presence of the blood-brain barrier (BBB). The BBB is the anatomical barrier that protects the brain from undesirable agents. Although some NPs have been derivatized at their surface to cross the BBB, optimal NPs to deliver oligonucleotide RNA into GBM cells in the brain are currently unavailable. In this review, we describe first the current treatments for GBM therapy. Next, we discuss the most relevant miRNAs and lncRNAs suggested as targets for GBM therapy. Then, we compare the current drug delivery systems (nanocarriers/NPs) for RNA oligonucleotide delivery, the challenges faced to send drugs through the BBB, and the strategies to overcome this barrier. Finally, we categorize the critical points where research should be the focus in order to design optimal NPs for drug delivery into the brain; and thus move the Oligonucleotide RNA-based therapies from the bench to the clinical setting.
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Affiliation(s)
- Rohit K. Sharma
- Comprehensive Cancer Center, University of Puerto Rico, San Juan, PR, United States
| | - Carlos Calderon
- Comprehensive Cancer Center, University of Puerto Rico, San Juan, PR, United States
| | - Pablo E. Vivas-Mejia
- Comprehensive Cancer Center, University of Puerto Rico, San Juan, PR, United States
- Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, San Juan, PR, United States
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111
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Involvement of ectonucleotidases and purinergic receptor expression during acute Chagas disease in the cortex of mice treated with resveratrol and benznidazole. Purinergic Signal 2021; 17:493-502. [PMID: 34302569 DOI: 10.1007/s11302-021-09803-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 06/18/2021] [Indexed: 11/27/2022] Open
Abstract
Chagas disease (CD) is caused by the parasite Trypanosoma cruzi. CD affects people worldwide, primarily in tropical areas. The central nervous system (CNS) is an essential site for T. cruzi persistence during infection. The protozoan may pass through the blood-brain barrier and may cause motor and cognitive neuronal damage. Once in the CNS, T. cruzi triggers immune responses that the purinergic system can regulate. Treatment for CD is based on benznidazole (BNZ); however, this agent has negative side-effects and is toxic to the host. For this reason, we investigated whether resveratrol (RSV), a potent antioxidant and neuroprotective molecule, would modulate purinergic signaling and RSV alone or in combination with BNZ would prevent changes in purinergic signaling and oxidative damage caused by T. cruzi. We infected mice with T. cruzi and treated them with RSV or BNZ for 8 days. Increases in ATP and ADP hydrolysis by NTPDase in the total cortex of infected animals were observed. The treatment with RSV in infected group diminished ATP, ADP, and AMP hydrolysis compared to infected group. The combination of RSV + BNZ decreased AMP hydrolysis in infected animals compared to the INF group, exerting an anti-inflammatory effect. RSV acted as a neuroprotector, decreasing adenosine levels. Infected animals presented an increase of P2X7 and A2A density of purine receptors. RSV reduced P2X7 and A2A and increased A1 density receptors in infected animals. In addition, infected animals showed higher TBARS and reactive oxygen species (ROS) levels than control. RSV diminished ROS levels in infected mice, possibly due to antioxidant properties. In short, we conclude that resveratrol could act as a neuroprotective molecule, probably preventing inflammatory changes caused by infection by T. cruzi, even though the mice experienced high levels of parasitemia.
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112
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Wu YC, Sonninen TM, Peltonen S, Koistinaho J, Lehtonen Š. Blood-Brain Barrier and Neurodegenerative Diseases-Modeling with iPSC-Derived Brain Cells. Int J Mol Sci 2021; 22:7710. [PMID: 34299328 PMCID: PMC8307585 DOI: 10.3390/ijms22147710] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022] Open
Abstract
The blood-brain barrier (BBB) regulates the delivery of oxygen and important nutrients to the brain through active and passive transport and prevents neurotoxins from entering the brain. It also has a clearance function and removes carbon dioxide and toxic metabolites from the central nervous system (CNS). Several drugs are unable to cross the BBB and enter the CNS, adding complexity to drug screens targeting brain disorders. A well-functioning BBB is essential for maintaining healthy brain tissue, and a malfunction of the BBB, linked to its permeability, results in toxins and immune cells entering the CNS. This impairment is associated with a variety of neurological diseases, including Alzheimer's disease and Parkinson's disease. Here, we summarize current knowledge about the BBB in neurodegenerative diseases. Furthermore, we focus on recent progress of using human-induced pluripotent stem cell (iPSC)-derived models to study the BBB. We review the potential of novel stem cell-based platforms in modeling the BBB and address advances and key challenges of using stem cell technology in modeling the human BBB. Finally, we highlight future directions in this area.
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Affiliation(s)
- Ying-Chieh Wu
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
| | - Tuuli-Maria Sonninen
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
| | - Sanni Peltonen
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
| | - Jari Koistinaho
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Šárka Lehtonen
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
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113
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Serpa RO, Ferguson L, Larson C, Bailard J, Cooke S, Greco T, Prins ML. Pathophysiology of Pediatric Traumatic Brain Injury. Front Neurol 2021; 12:696510. [PMID: 34335452 PMCID: PMC8319243 DOI: 10.3389/fneur.2021.696510] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/21/2021] [Indexed: 11/23/2022] Open
Abstract
The national incidence of traumatic brain injury (TBI) exceeds that of any other disease in the pediatric population. In the United States the Centers for Disease Control and Prevention (CDC) reports 697,347 annual TBIs in children ages 0–19 that result in emergency room visits, hospitalization or deaths. There is a bimodal distribution within the pediatric TBI population, with peaks in both toddlers and adolescents. Preclinical TBI research provides evidence for age differences in acute pathophysiology that likely contribute to long-term outcome differences between age groups. This review will examine the timecourse of acute pathophysiological processes during cerebral maturation, including calcium accumulation, glucose metabolism and cerebral blood flow. Consequences of pediatric TBI are complicated by the ongoing maturational changes allowing for substantial plasticity and windows of vulnerabilities. This review will also examine the timecourse of later outcomes after mild, repeat mild and more severe TBI to establish developmental windows of susceptibility and altered maturational trajectories. Research progress for pediatric TBI is critically important to reveal age-associated mechanisms and to determine knowledge gaps for future studies.
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Affiliation(s)
- Rebecka O Serpa
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Lindsay Ferguson
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Cooper Larson
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Julie Bailard
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Samantha Cooke
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Tiffany Greco
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Mayumi L Prins
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
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114
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Huang Z, Tan S. P2X7 Receptor as a Potential Target for Major Depressive Disorder. Curr Drug Targets 2021; 22:1108-1120. [PMID: 33494675 DOI: 10.2174/1389450122666210120141908] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 11/22/2022]
Abstract
Major depressive disorder (MDD) is a common mental disorder. Although the genetic, biochemical, and psychological factors have been related to the development of MDD, it is generally believed that a series of pathological changes in the brain caused by chronic stress is the main cause of MDD. However, the specific mechanisms underlying chronic stress-induced MDD are largely undermined. Recent investigations have found that increased pro-inflammatory cytokines and changes in the inflammatory pathway in the microglia cells in the brain are the potential pathophysiological mechanism of MDD. P2X7 receptor (P2X7R) and its mediated signaling pathway play a key role in microglia activation. The present review aimed to present and discuss the accumulating data on the role of P2X7R in MDD. Firstly, we summarized the research progress in the correlation between P2X7R and MDD. Subsequently, we presented the P2X7R mediated microglia activation in MDD and the role of P2X7R in increased blood-brain barrier (BBB) permeability caused by chronic stress. Lastly, we also discussed the potential mechanism underlying-P2X7R expression changes after chronic stress. In conclusion, P2X7R is a key molecule regulating the activation of microglia. Chronic stress activates microglia in the hippocampus by secreting interleukin- 1β (IL-1β) and other inflammatory cytokines, and increasing the BBB permeability, thus promoting the occurrence and development of MDD, which indicated that P2X7R might be a promising therapeutic target for MDD.
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Affiliation(s)
- Zeyi Huang
- Department of Histology and Embryology, Institute of Clinical Anatomy & Reproductive Medicine, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, 421001, Hunan, China
| | - Sijie Tan
- Department of Histology and Embryology, Institute of Clinical Anatomy & Reproductive Medicine, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, 421001, Hunan, China
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115
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Bernier LP, Brunner C, Cottarelli A, Balbi M. Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit. Front Cell Neurosci 2021; 15:696540. [PMID: 34276312 PMCID: PMC8277940 DOI: 10.3389/fncel.2021.696540] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/31/2021] [Indexed: 12/27/2022] Open
Abstract
The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.
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Affiliation(s)
- Louis-Philippe Bernier
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium.,Vlaams Instituut voor Biotechnologie, Leuven, Belgium.,Interuniversity Microeletronics Centre, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | | | - Matilde Balbi
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia
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116
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Mazaré N, Oudart M, Moulard J, Cheung G, Tortuyaux R, Mailly P, Mazaud D, Bemelmans AP, Boulay AC, Blugeon C, Jourdren L, Le Crom S, Rouach N, Cohen-Salmon M. Local Translation in Perisynaptic Astrocytic Processes Is Specific and Changes after Fear Conditioning. Cell Rep 2021; 32:108076. [PMID: 32846133 PMCID: PMC7450274 DOI: 10.1016/j.celrep.2020.108076] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/08/2020] [Accepted: 08/05/2020] [Indexed: 12/14/2022] Open
Abstract
Local translation is a conserved mechanism conferring cells the ability to quickly respond to local stimuli. In the brain, it has been recently reported in astrocytes, whose fine processes contact blood vessels and synapses. Yet the specificity and regulation of astrocyte local translation remain unknown. We study hippocampal perisynaptic astrocytic processes (PAPs) and show that they contain the machinery for translation. Using a refined immunoprecipitation technique, we characterize the entire pool of ribosome-bound mRNAs in PAPs and compare it with the one expressed in the whole astrocyte. We find that a specific pool of mRNAs is highly polarized at the synaptic interface. These transcripts encode an unexpected molecular repertoire, composed of proteins involved in iron homeostasis, translation, cell cycle, and cytoskeleton. Remarkably, we observe alterations in global RNA distribution and ribosome-bound status of some PAP-enriched transcripts after fear conditioning, indicating the role of astrocytic local translation in memory and learning. Local translation occurs in perisynaptic astrocytic processes (PAPs) The repertoire of ribosome-bound mRNAs enriched in hippocampal PAPs is specific RNA distribution and local translation change in PAPs after fear conditioning
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Affiliation(s)
- Noémie Mazaré
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France; Doctoral School No. 158, Pierre and Marie Curie University, 75005 Paris, France
| | - Marc Oudart
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France; Doctoral School No. 158, Pierre and Marie Curie University, 75005 Paris, France
| | - Julien Moulard
- Doctoral School No. 158, Pierre and Marie Curie University, 75005 Paris, France; Neuroglial Interactions in Cerebral Physiopathology Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Giselle Cheung
- Neuroglial Interactions in Cerebral Physiopathology Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Romain Tortuyaux
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Philippe Mailly
- Orion Imaging Facility, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - David Mazaud
- Neuroglial Interactions in Cerebral Physiopathology Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Alexis-Pierre Bemelmans
- CEA, DRF, Institut de Biologie François Jacob, Molecular Imaging Research Center (MIRCen), 92265 Fontenay-aux-Roses, France; CNRS, CEA, Université Paris-Sud, Université Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), 92265 Fontenay-aux-Roses, France
| | - Anne-Cécile Boulay
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Corinne Blugeon
- Genomic Facility, Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Laurent Jourdren
- Genomic Facility, Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Stéphane Le Crom
- Genomic Facility, Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France; Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratory of Computational and Quantitative Biology (LCQB), 75005 Paris, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Martine Cohen-Salmon
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France.
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117
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Zaman V, Shields DC, Shams R, Drasites KP, Matzelle D, Haque A, Banik NL. Cellular and molecular pathophysiology in the progression of Parkinson's disease. Metab Brain Dis 2021; 36:815-827. [PMID: 33599945 PMCID: PMC8170715 DOI: 10.1007/s11011-021-00689-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/10/2021] [Indexed: 12/12/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder etiologically linked to the loss of substantia nigra (SN) dopaminergic neurons in the mid-brain. The etiopathology of sporadic PD is still unclear; however, the interaction of extrinsic and intrinsic factors may play a critical role in the onset and progression of the disease. Studies in animal models and human post-mortem tissue have identified distinct cellular and molecular changes in the diseased brain, suggesting complex interactions between different glial cell types and various molecular pathways. Small changes in the expression of specific genes in a single pathway or cell type possibly influence others at the cellular and system levels. These molecular and cellular signatures like neuroinflammation, oxidative stress, and autophagy have been observed in PD patients' brain tissue. While the etiopathology of PD is still poorly understood, the interplay between glial cells and molecular events may play a crucial role in disease onset and progression.
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Affiliation(s)
- Vandana Zaman
- Ralph H. Johnson Veterans Administration Medical Center, 109 Bee St, Charleston, SC, 29401, USA
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas St., Suite 301, Charleston, SC, 29425, USA
| | - Donald C Shields
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas St., Suite 301, Charleston, SC, 29425, USA
| | - Ramsha Shams
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas St., Suite 301, Charleston, SC, 29425, USA
- Department of Health and Human Performance, The Citadel, 171 Moultrie St, Charleston, SC, 29409, USA
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC, 29425, USA
| | - Kelsey P Drasites
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas St., Suite 301, Charleston, SC, 29425, USA
- Department of Health and Human Performance, The Citadel, 171 Moultrie St, Charleston, SC, 29409, USA
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC, 29425, USA
| | - Denise Matzelle
- Ralph H. Johnson Veterans Administration Medical Center, 109 Bee St, Charleston, SC, 29401, USA
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC, 29425, USA
| | - Azizul Haque
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC, 29425, USA.
| | - Narendra L Banik
- Ralph H. Johnson Veterans Administration Medical Center, 109 Bee St, Charleston, SC, 29401, USA.
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas St., Suite 301, Charleston, SC, 29425, USA.
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC, 29425, USA.
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118
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Kriaučiūnaitė K, Pociūtė A, Kaušylė A, Pajarskienė J, Verkhratsky A, Pivoriūnas A. Concentration-dependent duality of bFGF in regulation of barrier properties of human brain endothelial cells. J Cell Physiol 2021; 236:7642-7654. [PMID: 33959949 DOI: 10.1002/jcp.30410] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/26/2021] [Indexed: 01/16/2023]
Abstract
Multiple paracrine factors regulate the barrier properties of human brain capillary endothelial cells (BCECs). Understanding the precise mode of action of these factors remains a challenging task, because of the limited availability of functionally competent BCECs and the use of serum-containing medium. In the present study, we employed a defined protocol for producing BCECs from human inducible pluripotent stem cells. We found that autocrine secretion of basic fibroblast growth factor (bFGF) is necessary for the establishment a tight BCECs barrier, as revealed by measurements of transendothelial electric resistance (TEER). In contrast, addition of exogenous bFGF in concentrations higher than 4 ng/ml inhibited TEER in a concentration-dependent manner. Exogenous bFGF did not significantly affect expression and distribution of tight junction proteins claudin-5, occludin and zonula occludens (ZO)-1. Treatment with FGF receptor blocker PD173074 (15 µM) suppressed inhibitory effects of bFGF and induced nuclear translocation of protein ZO-1. Inhibition of phosphoinositide 3-Kinase (PI-3K) with LY294002 (25 µM) significantly potentiated an inhibitory effect of bFGF on TEER indicating that PI-3K signalling pathway counteracts bFGF modulation of TEER. In conclusion, we show that autocrine bFGF secretion is necessary for the proper barrier function of BCECs, whereas exogenous bFGF in higher doses suppresses barrier resistance. Our findings demonstrate a dual role for bFGF in the regulation of BCEC barrier function.
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Affiliation(s)
- Karolina Kriaučiūnaitė
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Agnė Pociūtė
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Aida Kaušylė
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Justina Pajarskienė
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Alexei Verkhratsky
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania.,Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, UK.,Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Augustas Pivoriūnas
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
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119
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Astrocyte-Endotheliocyte Axis in the Regulation of the Blood-Brain Barrier. Neurochem Res 2021; 46:2538-2550. [PMID: 33961207 DOI: 10.1007/s11064-021-03338-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 12/18/2022]
Abstract
The evolution of blood-brain barrier paralleled centralisation of the nervous system: emergence of neuronal masses required control over composition of the interstitial fluids. The barriers were initially created by glial cells, which employed septate junctions to restrict paracellular diffusion in the invertebrates and tight junctions in some early vertebrates. The endothelial barrier, secured by tight and adherent junctions emerged in vertebrates and is common in mammals. Astrocytes form the parenchymal part of the blood-brain barrier and commutate with endothelial cells through secretion of growth factors, morphogens and extracellular vesicles. These secreted factors control the integrity of the blood-brain barrier through regulation of expression of tight junction proteins. The astrocyte-endotheliocyte communications are particularly important in various neurological diseases associated with impairments to the blood-brain barrier. Molecular mechanisms supporting astrocyte-endotheliocyte axis in health and disease are in need of detailed characterisation.
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120
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Seo S, Choi CH, Yi KS, Kim SU, Lee K, Choi N, Lee HJ, Cha SH, Kim HN. An engineered neurovascular unit for modeling neuroinflammation. Biofabrication 2021; 13. [PMID: 33849004 DOI: 10.1088/1758-5090/abf741] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/13/2021] [Indexed: 12/25/2022]
Abstract
The neurovascular unit (NVU) comprises multiple types of brain cells, including brain endothelial cells, astrocytes, pericytes, neurons, microglia, and oligodendrocytes. Each cell type contributes to the maintenance of the molecular transport barrier and brain tissue homeostasis. Several disorders and diseases of the central nervous system, including neuroinflammation, Alzheimer's disease, stroke, and multiple sclerosis, have been associated with dysfunction of the NVU. As a result, there has been increased demand for the development of NVUin vitromodels. Here, we present a three-dimensional (3D) immortalized human cell-based NVU model generated by organizing the brain microvasculature in a collagen matrix embedded with six different types of cells that comprise the NVU. By surrounding a perfusable brain endothelium with six types of NVU-composing cells, we demonstrated a significant impact of the 3D co-culture on the maturation of barrier function, which is supported by cytokines secreted from NVU-composing cells. Furthermore, NVU-composing cells alleviated the inflammatory responses induced by lipopolysaccharides. Our human cell-based NVUin vitromodel could enable elucidation of both physiological and pathological mechanisms in the human brain and evaluation of safety and efficacy in the context of high-content analysis during the process of drug development.
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Affiliation(s)
- Suyeong Seo
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.,Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, Republic of Korea.,These authors contributed equally to this work
| | - Chi-Hoon Choi
- Department of Radiology, Chung Buk National University Hospital, Cheongju, Chung Buk, Republic of Korea.,College of Medicine, Chung Buk National University, Cheongju, Chung Buk 28644, Republic of Korea.,These authors contributed equally to this work
| | - Kyung Sik Yi
- Department of Radiology, Chung Buk National University Hospital, Cheongju, Chung Buk, Republic of Korea
| | - Seung U Kim
- Division of Neurology, Department of Medicine, UBC Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Kangwon Lee
- Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, Republic of Korea
| | - Nakwon Choi
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
| | - Hong Jun Lee
- College of Medicine, Chung Buk National University, Cheongju, Chung Buk 28644, Republic of Korea.,Research Institute, eBiogen Inc., Seoul, Republic of Korea
| | - Sang-Hoon Cha
- Department of Radiology, Chung Buk National University Hospital, Cheongju, Chung Buk, Republic of Korea.,College of Medicine, Chung Buk National University, Cheongju, Chung Buk 28644, Republic of Korea
| | - Hong Nam Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea
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121
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Sun Z, Gao C, Gao D, Sun R, Li W, Wang F, Wang Y, Cao H, Zhou G, Zhang J, Shang J. Reduction in pericyte coverage leads to blood-brain barrier dysfunction via endothelial transcytosis following chronic cerebral hypoperfusion. Fluids Barriers CNS 2021; 18:21. [PMID: 33952281 PMCID: PMC8101037 DOI: 10.1186/s12987-021-00255-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/28/2021] [Indexed: 12/20/2022] Open
Abstract
Background Chronic cerebral hypoperfusion (CCH) is the leading cause of cerebral small vessel disease (CSVD). CCH is strongly associated with blood–brain barrier (BBB) dysfunction and white matter lesions (WMLs) in CSVD. However, the effects of CCH on BBB integrity and components and the cellular and molecular mechanisms underlying the effects of BBB dysfunction remain elusive. Whether maintaining BBB integrity can reverse CCH-induced brain damage has also not been explored. Methods In this study, we established a rat model of CSVD via permanent bilateral common carotid artery occlusion (2VO) to mimic the chronic hypoperfusive state of CSVD. The progression of BBB dysfunction and components of the BBB were assessed using immunostaining, Western blotting, transmission electron microscopy (TEM) and RNA sequencing. We also observed the protective role of imatinib, a tyrosine kinase inhibitor, on BBB integrity and neuroprotective function following CCH. The data were analyzed using one-way or two-way ANOVA. Results We noted transient yet severe breakdown of the BBB in the corpus callosum (CC) following CCH. The BBB was severely impaired as early as 1 day postoperation and most severely impaired 3 days postoperation. BBB breakdown preceded neuroinflammatory responses and the formation of WMLs. Moreover, pericyte loss was associated with BBB impairment, and the accumulation of serum protein was mediated by increased endothelial transcytosis in the CC. RNA sequencing also revealed increased transcytosis genes expression. BBB dysfunction led to brain damage through regulation of TGF-β/Smad2 signaling. Furthermore, imatinib treatment ameliorated serum protein leakage, oligodendrocyte progenitor cell (OPC) activation, endothelial transcytosis, microglial activation, and aberrant TGF-β/Smad2 signaling activation. Conclusions Our results indicate that reduced pericyte coverage leads to increased BBB permeability via endothelial transcytosis. Imatinib executes a protective role on the BBB integrity via inhibition of endothelial transcytosis. Maintenance of BBB integrity ameliorates brain damage through regulation of TGF-β/Smad2 signaling following CCH; therefore, reversal of BBB dysfunction may be a promising strategy for CSVD treatment. Supplementary Information The online version contains supplementary material available at 10.1186/s12987-021-00255-2.
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Affiliation(s)
- Zhengyu Sun
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Chenhao Gao
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Dandan Gao
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Ruihua Sun
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Wei Li
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Fengyu Wang
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Yanliang Wang
- Department of Nephrology, Henan Provincial Key Laboratory of Kidney Disease and Immunology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Huixia Cao
- Department of Nephrology, Henan Provincial Key Laboratory of Kidney Disease and Immunology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China
| | - Guoyu Zhou
- School of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan, China
| | - Jiewen Zhang
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China.
| | - Junkui Shang
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Henan University People's Hospital, Zhengzhou, 450003, Henan, China.
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Schofield CL, Rodrigo-Navarro A, Dalby MJ, Van Agtmael T, Salmeron-Sanchez M. Biochemical‐ and Biophysical‐Induced Barriergenesis in the Blood–Brain Barrier: A Review of Barriergenic Factors for Use in In Vitro Models. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202000068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
| | | | - Matthew J. Dalby
- Centre for the Cellular Microenvironment University of Glasgow Glasgow UK
| | - Tom Van Agtmael
- Institute of Cardiovascular and Medical Sciences University of Glasgow Glasgow UK
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Broadhead MJ, Miles GB. A common role for astrocytes in rhythmic behaviours? Prog Neurobiol 2021; 202:102052. [PMID: 33894330 DOI: 10.1016/j.pneurobio.2021.102052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 03/03/2021] [Accepted: 04/13/2021] [Indexed: 01/16/2023]
Abstract
Astrocytes are a functionally diverse form of glial cell involved in various aspects of nervous system infrastructure, from the metabolic and structural support of neurons to direct neuromodulation of synaptic activity. Investigating how astrocytes behave in functionally related circuits may help us understand whether there is any conserved logic to the role of astrocytes within neuronal networks. Astrocytes are implicated as key neuromodulatory cells within neural circuits that control a number of rhythmic behaviours such as breathing, locomotion and circadian sleep-wake cycles. In this review, we examine the evidence that astrocytes are directly involved in the regulation of the neural circuits underlying six different rhythmic behaviours: locomotion, breathing, chewing, gastrointestinal motility, circadian sleep-wake cycles and oscillatory feeding behaviour. We discuss how astrocytes are integrated into the neuronal networks that regulate these behaviours, and identify the potential gliotransmission signalling mechanisms involved. From reviewing the evidence of astrocytic involvement in a range of rhythmic behaviours, we reveal a heterogenous array of gliotransmission mechanisms, which help to regulate neuronal networks. However, we also observe an intriguing thread of commonality, in the form of purinergic gliotransmission, which is frequently utilised to facilitate feedback inhibition within rhythmic networks to constrain a given behaviour within its operational range.
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Affiliation(s)
- Matthew J Broadhead
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
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124
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Bourgeois-Tardif S, De Beaumont L, Rivera JC, Chemtob S, Weil AG. Role of innate inflammation in traumatic brain injury. Neurol Sci 2021; 42:1287-1299. [PMID: 33464411 DOI: 10.1007/s10072-020-05002-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/14/2020] [Indexed: 12/26/2022]
Abstract
Traumatic brain injury is one of the leading causes of morbidity and mortality throughout the world. Its increasing incidence, in addition to its fundamental role in the development of neurodegenerative disease, proves especially concerning. Despite extensive preclinical and clinical studies, researchers have yet to identify a safe and effective neuroprotective strategy. Following brain trauma, secondary injury from molecular, metabolic, and cellular changes causes progressive cerebral tissue damage. Chronic neuroinflammation following traumatic brain injuries is a key player in the development of secondary injury. Targeting this phenomenon for development of effective neuroprotective therapies holds promise. This strategy warrants a concrete understanding of complex neuroinflammatory mechanisms. In this review, we discuss pathophysiological mechanisms such as the innate immune response, glial activation, blood-brain barrier disruption, activation of immune mediators, as well as biological markers of traumatic brain injury. We then review existing and emerging pharmacological therapies that target neuroinflammation to improve functional outcome.
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Affiliation(s)
- Sandrine Bourgeois-Tardif
- Department of Neuroscience, University of Montreal, Montreal, Canada
- Hopital du Sacre-Coeur de Montreal, Universite de Montreal - Psychology, Montreal, QC, Canada
| | - Louis De Beaumont
- Hopital du Sacre-Coeur de Montreal, Universite de Montreal - Psychology, Montreal, QC, Canada
| | - José Carlos Rivera
- Department of Pediatrics, Ophthalmology and Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Research Center, 3175, Chemin Côte Ste-Catherine, Montreal, Quebec, Canada
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montreal, Quebec, Canada
| | - Sylvain Chemtob
- Department of Pediatrics, Ophthalmology and Pharmacology, Centre Hospitalier Universitaire Sainte-Justine Research Center, 3175, Chemin Côte Ste-Catherine, Montreal, Quebec, Canada
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Center, University of Montréal, Montreal, Quebec, Canada
| | - Alexander G Weil
- Neurosurgery Service, Department of Surgery, University of Montreal, Montreal, Canada.
- Centre Hospitalier Universitaire Sainte-Justine, Centre de Recherche, Room 3.17.100_6, 3175, Côte Sainte-Catherine, Montreal, Quebec, H3T 1C5, Canada.
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125
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RNA Localization and Local Translation in Glia in Neurological and Neurodegenerative Diseases: Lessons from Neurons. Cells 2021; 10:cells10030632. [PMID: 33809142 PMCID: PMC8000831 DOI: 10.3390/cells10030632] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
Cell polarity is crucial for almost every cell in our body to establish distinct structural and functional domains. Polarized cells have an asymmetrical morphology and therefore their proteins need to be asymmetrically distributed to support their function. Subcellular protein distribution is typically achieved by localization peptides within the protein sequence. However, protein delivery to distinct cellular compartments can rely, not only on the transport of the protein itself but also on the transport of the mRNA that is then translated at target sites. This phenomenon is known as local protein synthesis. Local protein synthesis relies on the transport of mRNAs to subcellular domains and their translation to proteins at target sites by the also localized translation machinery. Neurons and glia specially depend upon the accurate subcellular distribution of their proteome to fulfil their polarized functions. In this sense, local protein synthesis has revealed itself as a crucial mechanism that regulates proper protein homeostasis in subcellular compartments. Thus, deregulation of mRNA transport and/or of localized translation can lead to neurological and neurodegenerative diseases. Local translation has been more extensively studied in neurons than in glia. In this review article, we will summarize the state-of-the art research on local protein synthesis in neuronal function and dysfunction, and we will discuss the possibility that local translation in glia and deregulation thereof contributes to neurological and neurodegenerative diseases.
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126
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Anthony DP, Hegde M, Shetty SS, Rafic T, Mutalik S, Rao BSS. Targeting receptor-ligand chemistry for drug delivery across blood-brain barrier in brain diseases. Life Sci 2021; 274:119326. [PMID: 33711385 DOI: 10.1016/j.lfs.2021.119326] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/09/2021] [Accepted: 03/03/2021] [Indexed: 12/18/2022]
Abstract
The blood-brain barrier (BBB) is composed of a layer of endothelial cells that is interspersed with a series of tight junctions and characterized by the absence of fenestrations. The permeability of this barrier is controlled by junctions such as tight junctions and adherent junctions as well as several cells such as astrocytes, pericytes, vascular endothelial cells, neurons, microglia, and efflux transporters with relatively enhanced expression. It plays a major role in maintaining homeostasis in the brain and exerts a protective regulatory control on the influx and efflux of molecules. However, it proves to be a challenge for drug delivery strategies that target brain diseases like Dementia, Parkinson's Disease, Alzheimer's Disease, Brain Cancer or Stroke, Huntington's Disease, Lou Gehrig's Disease, etc. Conventional modes of drug delivery are invasive and have been known to contribute to a "leaky BBB", recent studies have highlighted the efficiency and relative safety of receptor-mediated drug delivery. Several receptors are exhibited on the BBB, and actively participate in nutrient uptake, and recognize specific ligands that modulate the process of endocytosis. The strategy employed in receptor-mediated drug delivery exploits this process of "tricking" the receptors into internalizing ligands that are conjugated to carrier systems like liposomes, nanoparticles, monoclonal antibodies, enzymes etc. These in turn are modified with drug molecules, therefore leading to delivery to desired target cells in brain tissue. This review comprehensively explores each of those receptors that can be modified to serve such purposes as well as the currently employed strategies that have led to increased cellular uptake and transport efficiency.
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Affiliation(s)
- Danielle Paige Anthony
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Manasa Hegde
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Shreya S Shetty
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Thasneema Rafic
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Srinivas Mutalik
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - B S Satish Rao
- Department of Radiation Biology & Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
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127
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Carrino D, Branca JJV, Becatti M, Paternostro F, Morucci G, Gulisano M, Di Cesare Mannelli L, Pacini A. Alcohol-Induced Blood-Brain Barrier Impairment: An In Vitro Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:2683. [PMID: 33799986 PMCID: PMC7967408 DOI: 10.3390/ijerph18052683] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 12/16/2022]
Abstract
In recent years, alcohol abuse has dramatically grown with deleterious consequence for people's health and, in turn, for health care costs. It has been demonstrated, in humans and animals, that alcohol intoxication induces neuroinflammation and neurodegeneration thus leading to brain impairments. Furthermore, it has been shown that alcohol consumption is able to impair the blood-brain barrier (BBB), but the molecular mechanisms underlining this detrimental effect have not been fully elucidated. For this reason, in this study we investigated the effects of alcohol exposure on a rat brain endothelial (RBE4) cell line, as an in vitro-validated model of brain microvascular endothelial cells. To assess whether alcohol caused a concentration-related response, the cells were treated at different times with increasing concentrations (10-1713 mM) of ethyl alcohol (EtOH). Microscopic and molecular techniques, such as cell viability assay, immunofluorescence and Western blotting, were used to examine the mechanisms involved in alcohol-induced brain endothelial cell alterations including tight junction distribution, apoptosis, and reactive oxygen species production. Our findings clearly demonstrate that alcohol causes the formation of gaps between cells by tight junction disassembly, triggered by the endoplasmic reticulum and oxidative stress, highlighted by GRP78 chaperone upregulation and increase in reactive oxygen species production, respectively. The results from this study shed light on the mechanisms underlying alcohol-induced blood-brain barrier dysfunction and a better understanding of these processes will allow us to take advantage of developing new therapeutic strategies in order to prevent the deleterious effects of alcohol.
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Affiliation(s)
- Donatello Carrino
- Department Experimental and Clinical Medicine, Anatomy and Histology Section, University of Firenze, 50134 Firenze, Italy; (D.C.); (J.J.V.B.); (F.P.); (M.G.)
| | - Jacopo Junio Valerio Branca
- Department Experimental and Clinical Medicine, Anatomy and Histology Section, University of Firenze, 50134 Firenze, Italy; (D.C.); (J.J.V.B.); (F.P.); (M.G.)
| | - Matteo Becatti
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Firenze, 50134 Firenze, Italy;
| | - Ferdinando Paternostro
- Department Experimental and Clinical Medicine, Anatomy and Histology Section, University of Firenze, 50134 Firenze, Italy; (D.C.); (J.J.V.B.); (F.P.); (M.G.)
| | - Gabriele Morucci
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy;
| | - Massimo Gulisano
- Department Experimental and Clinical Medicine, Anatomy and Histology Section, University of Firenze, 50134 Firenze, Italy; (D.C.); (J.J.V.B.); (F.P.); (M.G.)
| | - Lorenzo Di Cesare Mannelli
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Firenze, 50139 Firenze, Italy;
| | - Alessandra Pacini
- Department Experimental and Clinical Medicine, Anatomy and Histology Section, University of Firenze, 50134 Firenze, Italy; (D.C.); (J.J.V.B.); (F.P.); (M.G.)
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Pons-Espinal M, Blasco-Agell L, Consiglio A. Dissecting the non-neuronal cell contribution to Parkinson's disease pathogenesis using induced pluripotent stem cells. Cell Mol Life Sci 2021; 78:2081-2094. [PMID: 33210214 PMCID: PMC7966189 DOI: 10.1007/s00018-020-03700-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 10/10/2020] [Accepted: 10/31/2020] [Indexed: 01/02/2023]
Abstract
Parkinson's disease (PD) is an incurable age-linked neurodegenerative disease with characteristic movement impairments that are caused by the progressive loss of dopamine-containing neurons (DAn) within the substantia nigra pars compacta. It has been suggested that misfolded protein aggregates together with neuroinflammation and glial reactivity, may impact nerve cell function, leading to neurodegeneration and diseases, such as PD. However, not many studies have been able to examine the role of human glial cells in the pathogenesis of PD. With the advent of induced pluripotent stem cell (iPSC) technology, it is now possible to reprogram human somatic cells to pluripotency and to generate viable human patient-specific DA neurons and glial cells, providing a tremendous opportunity for dissecting cellular and molecular pathological mechanisms occurring at early stages of PD. This reviews will report on recent work using human iPSC and 3D brain organoid models showing that iPSC technology can be used to recapitulate PD-relevant disease-associated phenotypes, including protein aggregation, cell death or loss of neurite complexity and deficient autophagic vacuoles clearance and focus on the recent co-culture systems that are revealing new insights into the complex interactions that occur between different brain cell types during neurodegeneration. Consequently, such advances are the key to improve our understanding of PD pathology and generate potential targets for new therapies aimed at curing PD patients.
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Affiliation(s)
- Meritxell Pons-Espinal
- Department of Pathology and Experimental Therapeutics, Bellvitge University Hospital-IDIBELL, 08908, Hospitalet de Llobregat, Spain.
- Institute of Biomedicine (IBUB) of the University of Barcelona (UB), 08028, Barcelona, Spain.
| | - Lucas Blasco-Agell
- Department of Pathology and Experimental Therapeutics, Bellvitge University Hospital-IDIBELL, 08908, Hospitalet de Llobregat, Spain
- Institute of Biomedicine (IBUB) of the University of Barcelona (UB), 08028, Barcelona, Spain
| | - Antonella Consiglio
- Department of Pathology and Experimental Therapeutics, Bellvitge University Hospital-IDIBELL, 08908, Hospitalet de Llobregat, Spain.
- Institute of Biomedicine (IBUB) of the University of Barcelona (UB), 08028, Barcelona, Spain.
- Department of Molecular and Translational Medicine, University of Brescia, Piazza del Mercato, 15, 25121, Brescia, BS, Italy.
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Zhu YM, Lin L, Wei C, Guo Y, Qin Y, Li ZS, Kent TA, McCoy CE, Wang ZX, Ni Y, Zhou XY, Zhang HL. The Key Regulator of Necroptosis, RIP1 Kinase, Contributes to the Formation of Astrogliosis and Glial Scar in Ischemic Stroke. Transl Stroke Res 2021; 12:991-1017. [PMID: 33629276 PMCID: PMC8557200 DOI: 10.1007/s12975-021-00888-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 12/15/2020] [Accepted: 01/05/2021] [Indexed: 11/25/2022]
Abstract
Necroptosis initiation relies on the receptor-interacting protein 1 kinase (RIP1K). We recently reported that genetic and pharmacological inhibition of RIP1K produces protection against ischemic stroke-induced astrocytic injury. However, the role of RIP1K in ischemic stroke-induced formation of astrogliosis and glial scar remains unknown. Here, in a transient middle cerebral artery occlusion (tMCAO) rat model and an oxygen and glucose deprivation and reoxygenation (OGD/Re)-induced astrocytic injury model, we show that RIP1K was significantly elevated in the reactive astrocytes. Knockdown of RIP1K or delayed administration of RIP1K inhibitor Nec-1 down-regulated the glial scar markers, improved ischemic stroke-induced necrotic morphology and neurologic deficits, and reduced the volume of brain atrophy. Moreover, knockdown of RIP1K attenuated astrocytic cell death and proliferation and promoted neuronal axonal generation in a neuron and astrocyte co-culture system. Both vascular endothelial growth factor D (VEGF-D) and its receptor VEGFR-3 were elevated in the reactive astrocytes; simultaneously, VEGF-D was increased in the medium of astrocytes exposed to OGD/Re. Knockdown of RIP1K down-regulated VEGF-D gene and protein levels in the reactive astrocytes. Treatment with 400 ng/ml recombinant VEGF-D induced the formation of glial scar; conversely, the inhibitor of VEGFR-3 suppressed OGD/Re-induced glial scar formation. RIP3K and MLKL may be involved in glial scar formation. Taken together, these results suggest that RIP1K participates in the formation of astrogliosis and glial scar via impairment of normal astrocyte responses and enhancing the astrocytic VEGF-D/VEGFR-3 signaling pathways. Inhibition of RIP1K promotes the brain functional recovery partially via suppressing the formation of astrogliosis and glial scar.
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Affiliation(s)
- Yong-Ming Zhu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Liang Lin
- The First Affiliated Hospital of Xiamen University, Xiamen, 361001, Fujian, China
| | - Chao Wei
- Department of Cardiology, The First Affiliated Hospital of Soochow University, 188 Shi-Zi Road, Suzhou, 215006, Jiangsu, China
| | - Yi Guo
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Yuan Qin
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Zhong-Sheng Li
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Thomas A Kent
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Department of Neurology, Houston Methodist Hospital, Houston, TX, USA
| | - Claire E McCoy
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, 123 St Stephens Greens, Dublin 2, Ireland
| | - Zhan-Xiang Wang
- The First Affiliated Hospital of Xiamen University, Xiamen, 361001, Fujian, China
| | - Yong Ni
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Xian-Yong Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Hui-Ling Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Laboratory of Cerebrovascular Pharmacology, College of Pharmaceutical Science, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, School of Public Health, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China.
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130
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Sun Q, Xu X, Wang T, Xu Z, Lu X, Li X, Chen G. Neurovascular Units and Neural-Glia Networks in Intracerebral Hemorrhage: from Mechanisms to Translation. Transl Stroke Res 2021; 12:447-460. [PMID: 33629275 DOI: 10.1007/s12975-021-00897-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 12/20/2022]
Abstract
Intracerebral hemorrhage (ICH), the most lethal type of stroke, often leads to poor outcomes in the clinic. Due to the complex mechanisms and cell-cell crosstalk during ICH, the neurovascular unit (NVU) was proposed to serve as a promising therapeutic target for ICH research. This review aims to summarize the development of pathophysiological shifts in the NVU and neural-glia networks after ICH. In addition, potential targets for ICH therapy are discussed in this review. Beyond cerebral blood flow, the NVU also plays an important role in protecting neurons, maintaining central nervous system (CNS) homeostasis, coordinating neuronal activity among supporting cells, forming and maintaining the blood-brain barrier (BBB), and regulating neuroimmune responses. During ICH, NVU dysfunction is induced, along with neuronal cell death, microglia and astrocyte activation, endothelial cell (EC) and tight junction (TJ) protein damage, and BBB disruption. In addition, it has been shown that certain targets and candidates can improve ICH-induced secondary brain injury based on an NVU and neural-glia framework. Moreover, therapeutic approaches and strategies for ICH are discussed.
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Affiliation(s)
- Qing Sun
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Xiang Xu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Tianyi Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Zhongmou Xu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Xiaocheng Lu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
| | - Xiang Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
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Aldewachi H, Al-Zidan RN, Conner MT, Salman MM. High-Throughput Screening Platforms in the Discovery of Novel Drugs for Neurodegenerative Diseases. Bioengineering (Basel) 2021; 8:30. [PMID: 33672148 PMCID: PMC7926814 DOI: 10.3390/bioengineering8020030] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/05/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Neurodegenerative diseases (NDDs) are incurable and debilitating conditions that result in progressive degeneration and/or death of nerve cells in the central nervous system (CNS). Identification of viable therapeutic targets and new treatments for CNS disorders and in particular, for NDDs is a major challenge in the field of drug discovery. These difficulties can be attributed to the diversity of cells involved, extreme complexity of the neural circuits, the limited capacity for tissue regeneration, and our incomplete understanding of the underlying pathological processes. Drug discovery is a complex and multidisciplinary process. The screening attrition rate in current drug discovery protocols mean that only one viable drug may arise from millions of screened compounds resulting in the need to improve discovery technologies and protocols to address the multiple causes of attrition. This has identified the need to screen larger libraries where the use of efficient high-throughput screening (HTS) becomes key in the discovery process. HTS can investigate hundreds of thousands of compounds per day. However, if fewer compounds could be screened without compromising the probability of success, the cost and time would be largely reduced. To that end, recent advances in computer-aided design, in silico libraries, and molecular docking software combined with the upscaling of cell-based platforms have evolved to improve screening efficiency with higher predictability and clinical applicability. We review, here, the increasing role of HTS in contemporary drug discovery processes, in particular for NDDs, and evaluate the criteria underlying its successful application. We also discuss the requirement of HTS for novel NDD therapies and examine the major current challenges in validating new drug targets and developing new treatments for NDDs.
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Affiliation(s)
- Hasan Aldewachi
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK;
- College of Pharmacy, Nineveh University, Mosul 41002, Iraq
| | - Radhwan N. Al-Zidan
- College of Pharmacy, University of Mosul, Mosul 41002, Iraq;
- School of Applied Sciences, Edinburgh Napier University, Edinburgh EH11 4BN, UK
| | - Matthew T. Conner
- School of Sciences, Research Institute in Healthcare Science, University of Wolverhampton, Wolverhampton WV1 1LY, UK;
| | - Mootaz M. Salman
- College of Pharmacy, University of Mosul, Mosul 41002, Iraq;
- Oxford Parkinson’s Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
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132
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González-Molina LA, Villar-Vesga J, Henao-Restrepo J, Villegas A, Lopera F, Cardona-Gómez GP, Posada-Duque R. Extracellular Vesicles From 3xTg-AD Mouse and Alzheimer's Disease Patient Astrocytes Impair Neuroglial and Vascular Components. Front Aging Neurosci 2021; 13:593927. [PMID: 33679370 PMCID: PMC7933224 DOI: 10.3389/fnagi.2021.593927] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 01/21/2021] [Indexed: 12/19/2022] Open
Abstract
Astrocytes are specialized glial cells that are essential components of the neurovascular unit (NVU) and are involved in neurodevelopment, brain maintenance and repair, and neurodegeneration. Astrocytes mediate these processes by releasing cellular mediators such as extracellular vesicles (EVs). EVs are vehicles of cell-cell communication and have been proposed as mediators of damage in AD. However, the transcellular mechanism by which Alzheimer disease (AD) astrocytes impair the function of NVU components is poorly understood. Therefore, we evaluated the effects of adult PS1-KI and 3xTg-AD astrocyte conditioned media (CM) and EVs on NVU components (neuroglia and endothelium) in vitro. Additionally, SAD and FAD astrocyte-derived EVs (A-EVs) were characterized, and we evaluated their effects on NVU in cocultured cells in vitro and on intrahippocampal CA1 cells in vivo. Surprisingly, cultured 3xTg-AD astrocytes showed increased glial fibrillary acidic protein (GFAP) reactivity compared to PS1-KI astrocytes, which denotes astrocytic hyperreactivity. CM from adult mice 3xTg-AD astrocytes increased cell-cell gaps between endothelial cells, filopodia-like dendritic protrusions in neurons and neuronal and endothelial cell death. 3xTg-AD A-EVs induced neurotoxicity and increased astrocyte GFAP reactivity. Cultured human postmortem astrocytes from AD patients also increased GFAP reactivity and EVs release. No differences in the size or number of A-EVs were detected between AD and control samples; however, both SAD and FAD A-EVs showed increased expression of the surface marker aquaporin 4. A-EVs induced cytotoxicity and astrocyte hyperactivation: specifically, FAD A-EVs induced neuroglial cytotoxicity and increased gaps between the endothelium, while SAD A-EVs mainly altered the endothelium. Similarly, both AD A-EVs increased astrocyte GS reactivity and vascular deterioration in vivo. We associated this finding with perivascular reactive astrocytes and vascular deterioration in the human AD brain. In summary, these results suggest that AD A-EVs impair neuroglial and vascular components.
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Affiliation(s)
- Luis Alfonso González-Molina
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellin, Colombia.,Facultad de Ciencias Exactas y Naturales, Instituto de Biología, Universidad de Antioquia, Medellin, Colombia
| | - Juan Villar-Vesga
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellin, Colombia.,Facultad de Ciencias Exactas y Naturales, Instituto de Biología, Universidad de Antioquia, Medellin, Colombia
| | - Julián Henao-Restrepo
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellin, Colombia.,Facultad de Ciencias Exactas y Naturales, Instituto de Biología, Universidad de Antioquia, Medellin, Colombia
| | - Andrés Villegas
- Neurobank, Neuroscience Group of Antioquia, Faculty of Medicine, SIU, University of Antioquia, Medellin, Colombia
| | - Francisco Lopera
- Neurobank, Neuroscience Group of Antioquia, Faculty of Medicine, SIU, University of Antioquia, Medellin, Colombia
| | - Gloria Patricia Cardona-Gómez
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellin, Colombia
| | - Rafael Posada-Duque
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Universidad de Antioquia, Medellin, Colombia.,Facultad de Ciencias Exactas y Naturales, Instituto de Biología, Universidad de Antioquia, Medellin, Colombia
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133
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EphA4 Obstructs Spinal Cord Neuron Regeneration by Promoting Excessive Activation of Astrocytes. Cell Mol Neurobiol 2021; 42:1557-1568. [PMID: 33595805 PMCID: PMC9142447 DOI: 10.1007/s10571-021-01046-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/15/2021] [Indexed: 12/12/2022]
Abstract
Studies have found that molecular targets that regulate tissue development are also involved in regulating tissue regeneration. Erythropoietin-producing hepatocyte A4 (EphA4) not only plays a guiding role in neurite outgrowth during the development of the central nervous system (CNS) but also induces injured axon retraction and inhibits axon regeneration after spinal cord injury (SCI). EphA4 targets several ephrin ligands (including ephrin-A and ephrin-B) and is involved in cortical cell migration, axon guidance, synapse formation and astrocyte function. However, how EphA4 affects axon regeneration after SCI remains unclear. This study focuses on the effect and mechanism of EphA4-regulated astrocyte function in neuronal regeneration after SCI. Our research found that EphA4 expression increased significantly after SCI and peaked at 3 days post-injury; accordingly, we identified the cellular localization of EphA4 and ephrin-B ligands in neurons and astrocytes after SCI. EphA4 was mainly expressed on the surface of neurons, ephrin-B1 and ephrin-B3 were mainly localized on astrocytes, and ephrin-B2 was distributed on both neurons and astrocytes. To further elucidate the effect of EphA4 on astrocyte function after SCI, we detected the related cytokines secreted by astrocytes in vivo. We found that the levels of neurotrophic factors including nerve growth factor (NGF) and basic fibroblast growth factor (bFGF) increased significantly after SCI (NGF peaked at 3 days and bFGF peaked at 7 days); the expression of laminin and fibronectin increased gradually after SCI; the expression of inflammatory factors [interleukin (IL)-1β and IL-6] increased significantly from 4 h to 7 days after SCI; and the levels of glial fibrillary acidic protein (GFAP), a marker of astrocyte activation, and chondroitin sulphate proteoglycan (CSPG), the main component of glial scars, both peaked at 7 days after SCI. Using a damaged astrocyte model in vitro, we similarly found that the levels of related cytokines increased after injury. Consequently, we observed the effect of damaged astrocytes on neurite outgrowth and regeneration, and the results showed that damaged astrocytes hindered neurite outgrowth and regeneration; however, the inhibitory effect of injured astrocytes on neurite regeneration was reduced following ephrin-B receptor knockdown or inflammatory inhibition at 24 h after astrocyte injury. Our results showed that EphA4 regulates the secretion of neurotrophic factors, adhesion molecules, inflammatory factors and glial scar formation by binding with the ligand ephrin-B located on the surface of astrocytes. EphA4 affects neurite outgrowth and regeneration after SCI by regulating astrocyte function.
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134
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Osemwegie O, Butler L, Subbiah S, Smith E. Effects of in vitro exposure of perfluorooctanoic acid and monocrotophos on astroglia SVG p12 cells. J Appl Toxicol 2021; 41:1380-1389. [PMID: 33569802 DOI: 10.1002/jat.4129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/21/2022]
Abstract
Glia cells provide supportive functions to the central nervous system and can be compromised by environmental contaminants. The primary objective of this study was to characterize the effects of in vitro exposure to perfluorooctanoic acid, a persistent environmental contaminant and/or monocrotophos (MCP), a neurotoxic organophosphate that is rapidly metabolized, to astroglia SVG p12 cells. The endpoints evaluated include cell viability, intracellular glutamate levels as a marker of astrocyte homeostasis function, differential gene expression for selected proteins, which include inflammatory markers (tachykinin), astrocytosis (nestin), S100B, and metabolism enzymes (CYP1A1). The results from cell viability revealed significant differences from the controls at some of the concentrations tested. Also, intracellular glutamate levels were elevated at the 10-μM concentration for perfluorooctanoic acid (PFOA) as well as the 10-μM PFOA/5-μM MCP concentration. Gene expression results at 80-μM PFOA concentration revealed a significant increase in the expression of S100B, tachykinin and CYP1A1. A combination of 10-μM PFOA/20-μM MCP caused a significant decrease in the expression of tachykinin. Gene expression for MCP exposures produced a decrease at the 20-μM MCP concentration. Immunofluorescence results indicated an increase in nestin protein expression for the 20-μM concentration of MCP, which contradicted the gene expression at the same concentration tested. The results indicate that toxicity to glia cells can compromise critical glia functions and could be implicated in neurodegenerative diseases.
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Affiliation(s)
- Odia Osemwegie
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - Landon Butler
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - Seenivasan Subbiah
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
| | - Ernest Smith
- Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA
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135
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Mazaré N, Oudart M, Cohen-Salmon M. Local translation in perisynaptic and perivascular astrocytic processes - a means to ensure astrocyte molecular and functional polarity? J Cell Sci 2021; 134:237323. [PMID: 33483366 DOI: 10.1242/jcs.251629] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Together with the compartmentalization of mRNAs in distal regions of the cytoplasm, local translation constitutes a prominent and evolutionarily conserved mechanism mediating cellular polarization and the regulation of protein delivery in space and time. The translational regulation of gene expression enables a rapid response to stimuli or to a change in the environment, since the use of pre-existing mRNAs can bypass time-consuming nuclear control mechanisms. In the brain, the translation of distally localized mRNAs has been mainly studied in neurons, whose cytoplasmic protrusions may be more than 1000 times longer than the diameter of the cell body. Importantly, alterations in local translation in neurons have been implicated in several neurological diseases. Astrocytes, the most abundant glial cells in the brain, are voluminous, highly ramified cells that project long processes to neurons and brain vessels, and dynamically regulate distal synaptic and vascular functions. Recent research has demonstrated the presence of local translation at these astrocytic interfaces that might regulate the functional compartmentalization of astrocytes. In this Review, we summarize our current knowledge about the localization and local translation of mRNAs in the distal perisynaptic and perivascular processes of astrocytes, and discuss their possible contribution to the molecular and functional polarity of astrocytes.
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Affiliation(s)
- Noémie Mazaré
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, F-75005 Paris, France.,École doctorale Cerveau Cognition Comportement 'ED3C' No. 158, Pierre and Marie Curie University, F-75005 Paris, France
| | - Marc Oudart
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, F-75005 Paris, France.,École doctorale Cerveau Cognition Comportement 'ED3C' No. 158, Pierre and Marie Curie University, F-75005 Paris, France
| | - Martine Cohen-Salmon
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, F-75005 Paris, France .,École doctorale Cerveau Cognition Comportement 'ED3C' No. 158, Pierre and Marie Curie University, F-75005 Paris, France
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136
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Woo YH, Martinez LR. Cryptococcus neoformans-astrocyte interactions: effect on fungal blood brain barrier disruption, brain invasion, and meningitis progression. Crit Rev Microbiol 2021; 47:206-223. [PMID: 33476528 DOI: 10.1080/1040841x.2020.1869178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cryptococcus neoformans is an opportunistic, neurotropic, and encapsulated fungus that causes life-threatening cryptococcal meningitis (CM), especially in regions of the world where AIDS is endemic. The polysaccharide capsule of C. neoformans is the fungus major virulent factor, being copiously released during infection and causing immunosuppressive defects in the host. Although the capsular material is commonly associated with reactive astrocytes in fatal CM, little is known about the molecular and cellular interactions among astroglia and C. neoformans. As astrocytes also make up the neurovascular unit at the blood-brain barrier (BBB), which C. neoformans must transverse to colonize the central nervous system and cause CM; these cells may play a significant regulatory role in the prevention and progression of infection. For example, astrocytes are implicated in neurological disease including the regulation of cerebral intracranial pressure, immune function, and water homeostasis. Hence, in this review, we provide a general overview of astroglia biology and discuss the current knowledge on C. neoformans-astrocyte interactions including their involvement in the development of CM. This "gliocentric view" of cerebral cryptococcosis suggests that therapeutic interventions particularly targeting at preserving the neuroprotective function of astrocytes may be used in preventing and managing C. neoformans BBB transmigration, brain invasion, colonization, and meningitis.
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Affiliation(s)
- Yeon Hwa Woo
- Department of Metallurgical, Materials and Biomedical Engineering, College of Engineering, The University of Texas at El Paso, El Paso, TX, USA
| | - Luis R Martinez
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
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137
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Siqueira M, Araujo APB, Gomes FCA, Stipursky J. Ethanol Gestational Exposure Impairs Vascular Development and Endothelial Potential to Control BBB-Associated Astrocyte Function in the Developing Cerebral Cortex. Mol Neurobiol 2021; 58:1755-1768. [PMID: 33387302 DOI: 10.1007/s12035-020-02214-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 11/16/2020] [Indexed: 10/22/2022]
Abstract
Ethanol consumption during pregnancy or lactation period can induce permanent damage to the development of the central nervous system (CNS), resulting in fetal alcohol spectrum disorders (FASD). CNS development depends on proper neural cells and blood vessel (BV) development and blood-brain barrier (BBB) establishment; however, little is known about how ethanol affects these events. Here, we investigated the impact of ethanol exposure to endothelial cells (ECs) function and to ECs interaction with astrocytes in the context of BBB establishment. Cerebral cortex of newborn mice exposed in utero to ethanol (FASD model) presented a hypervascularized phenotype, revealed by augmented vessel density, length, and branch points. Further, aberrant distribution of the tight junction ZO-1 protein along BVs and increased rates of perivascular astrocytic endfeet around BVs were observed. In vitro exposure of human brain microcapillary ECs (HBMEC) to ethanol significantly disrupted ZO-1 distribution, decreased Claudin-5 and GLUT-1 expression and impaired glucose uptake, and increased nitric oxide secretion. These events were accompanied by upregulation of angiogenesis-related secreted proteins by ECs in response to ethanol exposure. Treatment of cortical astrocytes with conditioned medium (CM) from ethanol exposed ECs, upregulated astrocyte's expression of GFAP, Cx43, and Lipocalin-2 genes, as well as the pro-inflammatory genes, IL-1beta, IL-6, and TNF-alpha, which was accompanied by NF-kappa B protein nuclear accumulation. Our findings suggest that ethanol triggers a dysfunctional phenotype in brain ECs, leading to impairment of cortical vascular network formation, and promotes ECs-induced astrocyte dysfunction, which could dramatically affect BBB establishment in the developing brain.
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Affiliation(s)
- Michele Siqueira
- Laboratório de Neurobiologia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Bloco F, Sala F15, Ilha do Fundão, Rio de Janeiro, RJ, 21949-902, Brazil
| | - Ana Paula Bérgamo Araujo
- Laboratório de Neurobiologia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Bloco F, Sala F15, Ilha do Fundão, Rio de Janeiro, RJ, 21949-902, Brazil
| | - Flávia Carvalho Alcantara Gomes
- Laboratório de Neurobiologia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Bloco F, Sala F15, Ilha do Fundão, Rio de Janeiro, RJ, 21949-902, Brazil
| | - Joice Stipursky
- Laboratório de Neurobiologia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Bloco F, Sala F15, Ilha do Fundão, Rio de Janeiro, RJ, 21949-902, Brazil.
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138
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Piantino M, Figarol A, Matsusaki M. Three-Dimensional in vitro Models of Healthy and Tumor Brain Microvasculature for Drug and Toxicity Screening. FRONTIERS IN TOXICOLOGY 2021; 3:656254. [PMID: 35295158 PMCID: PMC8915870 DOI: 10.3389/ftox.2021.656254] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/31/2021] [Indexed: 12/16/2022] Open
Abstract
Tissue vascularization is essential for its oxygenation and the homogenous diffusion of nutrients. Cutting-edge studies are focusing on the vascularization of three-dimensional (3D) in vitro models of human tissues. The reproduction of the brain vasculature is particularly challenging as numerous cell types are involved. Moreover, the blood-brain barrier, which acts as a selective filter between the vascular system and the brain, is a complex structure to replicate. Nevertheless, tremendous advances have been made in recent years, and several works have proposed promising 3D in vitro models of the brain microvasculature. They incorporate cell co-cultures organized in 3D scaffolds, often consisting of components of the native extracellular matrix (ECM), to obtain a micro-environment similar to the in vivo physiological state. These models are particularly useful for studying adverse effects on the healthy brain vasculature. They provide insights into the molecular and cellular events involved in the pathological evolutions of this vasculature, such as those supporting the appearance of brain cancers. Glioblastoma multiform (GBM) is the most common form of brain cancer and one of the most vascularized solid tumors. It is characterized by a high aggressiveness and therapy resistance. Current conventional therapies are unable to prevent the high risk of recurrence of the disease. Most of the new drug candidates fail to pass clinical trials, despite the promising results shown in vitro. The conventional in vitro models are unable to efficiently reproduce the specific features of GBM tumors. Recent studies have indeed suggested a high heterogeneity of the tumor brain vasculature, with the coexistence of intact and leaky regions resulting from the constant remodeling of the ECM by glioma cells. In this review paper, after summarizing the advances in 3D in vitro brain vasculature models, we focus on the latest achievements in vascularized GBM modeling, and the potential applications for both healthy and pathological models as platforms for drug screening and toxicological assays. Particular attention will be paid to discuss the relevance of these models in terms of cell-cell, cell-ECM interactions, vascularization and permeability properties, which are crucial parameters for improving in vitro testing accuracy.
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Affiliation(s)
- Marie Piantino
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Agathe Figarol
- Institut Jean Lamour, UMR 7198 CNRS, Université de Lorraine, Nancy, France
| | - Michiya Matsusaki
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka, Japan
- *Correspondence: Michiya Matsusaki
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139
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Dudek KA, Dion‐Albert L, Kaufmann FN, Tuck E, Lebel M, Menard C. Neurobiology of resilience in depression: immune and vascular insights from human and animal studies. Eur J Neurosci 2021; 53:183-221. [PMID: 31421056 PMCID: PMC7891571 DOI: 10.1111/ejn.14547] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/22/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
Major depressive disorder (MDD) is a chronic and recurrent psychiatric condition characterized by depressed mood, social isolation and anhedonia. It will affect 20% of individuals with considerable economic impacts. Unfortunately, 30-50% of depressed individuals are resistant to current antidepressant treatments. MDD is twice as prevalent in women and associated symptoms are different. Depression's main environmental risk factor is chronic stress, and women report higher levels of stress in daily life. However, not every stressed individual becomes depressed, highlighting the need to identify biological determinants of stress vulnerability but also resilience. Based on a reverse translational approach, rodent models of depression were developed to study the mechanisms underlying susceptibility vs resilience. Indeed, a subpopulation of animals can display coping mechanisms and a set of biological alterations leading to stress resilience. The aetiology of MDD is multifactorial and involves several physiological systems. Exacerbation of endocrine and immune responses from both innate and adaptive systems are observed in depressed individuals and mice exhibiting depression-like behaviours. Increasing attention has been given to neurovascular health since higher prevalence of cardiovascular diseases is found in MDD patients and inflammatory conditions are associated with depression, treatment resistance and relapse. Here, we provide an overview of endocrine, immune and vascular changes associated with stress vulnerability vs. resilience in rodents and when available, in humans. Lack of treatment efficacy suggests that neuron-centric treatments do not address important causal biological factors and better understanding of stress-induced adaptations, including sex differences, could contribute to develop novel therapeutic strategies including personalized medicine approaches.
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Affiliation(s)
- Katarzyna A. Dudek
- Department of Psychiatry and NeuroscienceFaculty of Medicine and CERVO Brain Research CenterUniversité LavalQuebec CityQCCanada
| | - Laurence Dion‐Albert
- Department of Psychiatry and NeuroscienceFaculty of Medicine and CERVO Brain Research CenterUniversité LavalQuebec CityQCCanada
| | - Fernanda Neutzling Kaufmann
- Department of Psychiatry and NeuroscienceFaculty of Medicine and CERVO Brain Research CenterUniversité LavalQuebec CityQCCanada
| | - Ellen Tuck
- Smurfit Institute of GeneticsTrinity CollegeDublinIreland
| | - Manon Lebel
- Department of Psychiatry and NeuroscienceFaculty of Medicine and CERVO Brain Research CenterUniversité LavalQuebec CityQCCanada
| | - Caroline Menard
- Department of Psychiatry and NeuroscienceFaculty of Medicine and CERVO Brain Research CenterUniversité LavalQuebec CityQCCanada
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140
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Gaindh D, Choi YB, Marchese M, Dowling P, Cook S, Blumberg B, Park JH, Lu W. Prolonged Beneficial Effect of Brief Erythropoietin Peptide JM4 Therapy on Chronic Relapsing EAE. Neurotherapeutics 2021; 18:401-411. [PMID: 32959273 PMCID: PMC8116362 DOI: 10.1007/s13311-020-00923-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2020] [Indexed: 12/28/2022] Open
Abstract
Potent beneficial immunomodulatory and anti-inflammatory effects of whole-molecule erythropoietin have been demonstrated in a variety of animal disease models including experimental autoimmune encephalomyelitis (EAE); however, excessive hematopoiesis limits its use in clinical applications. Our group previously generated an Epo-derived small peptide JM4 that is side-effect free and has strong neuroprotective activity without hematologic effects. Here, we investigated the long-term clinical effects of brief treatment with JM4 in chronic relapsing EAE using bioluminescence imaging (BLI) in transgenic mice containing the luciferase gene driven by the murine GFAP promoter. EAE mice treated with JM4 exhibited marked improvement in clinical scores and showed fewer disease flareups than control animals. JM4 therapy concomitantly led to markedly decreased GFAP bioluminescence in the brain and spinal cord in both acute and chronic relapsing EAE mouse models. We found a marker for toxic A1 astrocytes, complement component C3, that is upregulated in the brain and cord of EAE mice and sharply reduced in JM4-treated animals. In addition, an abnormally leaky neurovascular unit permeability was rapidly normalized within 5 days by JM4 therapy. The prolonged therapeutic benefit seen following brief JM4 treatment in EAE mice closely resemble that recently described in humans receiving pulsed immune reconstitution therapy with the disease-modifying compounds, alemtuzumab and cladribine. Our study suggests that JM4 therapy may have widespread clinical applicability for long-term treatment of inflammatory demyelinating diseases and that BLI is a useful noninvasive means of monitoring murine disease activity of the central nervous system.
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Affiliation(s)
- Deeya Gaindh
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA.
- Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA.
| | - Yun-Beom Choi
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
- Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Michelle Marchese
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
| | - Peter Dowling
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
- Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Stuart Cook
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
- Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Benjamin Blumberg
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
| | - James H Park
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
| | - Wei Lu
- Neurology Service, VA Medical Center of East Orange, East Orange, NJ, USA
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141
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Role of astroglial Connexin 43 in pneumolysin cytotoxicity and during pneumococcal meningitis. PLoS Pathog 2020; 16:e1009152. [PMID: 33370401 PMCID: PMC7793270 DOI: 10.1371/journal.ppat.1009152] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 01/08/2021] [Accepted: 11/11/2020] [Indexed: 12/19/2022] Open
Abstract
Streptococcus pneumoniae or pneumococcus (PN) is a major causative agent of bacterial meningitis with high mortality in young infants and elderly people worldwide. The mechanism underlying PN crossing of the blood brain barrier (BBB) and specifically, the role of non-endothelial cells of the neurovascular unit that control the BBB function, remains poorly understood. Here, we show that the astroglial connexin 43 (aCx43), a major gap junctional component expressed in astrocytes, plays a predominant role during PN meningitis. Following intravenous PN challenge, mice deficient for aCx43 developed milder symptoms and showed severely reduced bacterial counts in the brain. Immunofluorescence analysis of brain slices indicated that PN induces the aCx43–dependent destruction of the network of glial fibrillary acid protein (GFAP), an intermediate filament protein specifically expressed in astrocytes and up-regulated in response to brain injury. PN also induced nuclear shrinkage in astrocytes associated with the loss of BBB integrity, bacterial translocation across endothelial vessels and replication in the brain cortex. We found that aCx4-dependent astrocyte damages could be recapitulated using in vitro cultured cells upon challenge with wild-type PN but not with a ply mutant deficient for the pore-forming toxin pneumolysin (Ply). Consistently, we showed that purified Ply requires Cx43 to promote host cell plasma membrane permeabilization in a process involving the Cx43-dependent release of extracellular ATP and prolonged increase of cytosolic Ca2+ in host cells. These results point to a critical role for astrocytes during PN meningitis and suggest that the cytolytic activity of the major virulence factor Ply at concentrations relevant to bacterial infection requires co-opting of connexin plasma membrane channels. The role of non-endothelial cells constituting the neurovascular unit during infectious meningitis is poorly appreciated despite their key regulatory functions on the blood-brain barrier integrity. Here, we show that Streptococcus pneumoniae or pneumococcus, a major causative agent of bacterial meningitis, targets astroglial cells to translocate across brain endothelial vessels. We found that astroglial connexin 43, a gap junctional component, played a major role during PN meningitis in mice. PN translocation and replication in the brain cortex were associated with connexin-dependent fragmentation of astrocytic the GFAP network, a process associated with brain injury. These findings were recapitulated and extended in vitro using cultured primary astrocytes and the major PN virulence determinant Pneumolysin. Ply-mediated cytotoxicity was linked to Ca2+ increase and required aCx43, arguing against a direct toxin activity. The results reveal a key role for astroglial signaling during PN crossing of the BBB and shed light on the mechanism of Ply-mediated cytotoxicity during meningitis.
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142
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Xing G, Zhao T, Zhang X, Li H, Li X, Cui P, Li M, Li D, Zhang N, Jiang W. Astrocytic Sonic Hedgehog Alleviates Intracerebral Hemorrhagic Brain Injury via Modulation of Blood-Brain Barrier Integrity. Front Cell Neurosci 2020; 14:575690. [PMID: 33343302 PMCID: PMC7747855 DOI: 10.3389/fncel.2020.575690] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/08/2020] [Indexed: 11/21/2022] Open
Abstract
Background: Intracerebral hemorrhage (ICH) is a fatal subtype of stroke that lacks effective therapy. Blood-brain barrier (BBB) damage is a hallmark of ICH-induced brain injury that leads to edema formation, leukocytes infiltration, influx of blood components into the perihematomal (PHE) region, and eventually brain injury. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted molecules that contribute to the association between these cells. Sonic hedgehog (SHH) derived from astrocytes promotes the maturity and integrity of the BBB by upregulating tight junctions (TJs) in brain capillary endothelial cells (ECs). However, the effect of SHH on BBB in ICH has not been investigated. Methods: Cyclopamine (CYC) is a potent, selective inhibitor that specifically blocks the SHH signaling pathway. Here, we used pharmacological inhibitions (CYC and its derivatives) to determine a critical role of the SHH signaling pathway in promoting BBB integrity after ICH by mechanisms of regulating the TJ proteins in vivo and in vitro. Results: The expression of astrocytic SHH was upregulated in mouse brains after ICH. Compared with the vehicle-treated group, inhibition of the SHH signaling pathway with CYC and its derivatives treatments aggravated neurological function deficits, brain edema, hematoma volume, and BBB impairment by downregulating TJs in ECs through the SHH-Gli-1 axis in vivo and in vitro. Conclusions: SHH signaling pathway at the level of the BBB provides a barrier-promoting effect, suggesting that the SHH signaling pathway may function as a potential therapeutic target for restoring BBB function in ICH.
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Affiliation(s)
- Gebeili Xing
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China.,Department of Neurology, Inner Mongolia People's Hospital, Hohhot, China
| | - Tianman Zhao
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Xiyue Zhang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - He Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Xiuping Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Pan Cui
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Minshu Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Daojing Li
- Department of Neurology, Affiliated Hospital of Jining Medical University, Jining, China
| | - Nan Zhang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Wei Jiang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
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143
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Al-Bachari S, Naish JH, Parker GJM, Emsley HCA, Parkes LM. Blood-Brain Barrier Leakage Is Increased in Parkinson's Disease. Front Physiol 2020; 11:593026. [PMID: 33414722 PMCID: PMC7784911 DOI: 10.3389/fphys.2020.593026] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 11/24/2020] [Indexed: 12/21/2022] Open
Abstract
Background Blood–brain barrier (BBB) disruption has been noted in animal models of Parkinson’s disease (PD) and forms the basis of the vascular hypothesis of neurodegeneration, yet clinical studies are lacking. Objective To determine alterations in BBB integrity in PD, with comparison to cerebrovascular disease. Methods Dynamic contrast enhanced magnetic resonance images were collected from 49 PD patients, 15 control subjects with cerebrovascular disease [control positive (CP)] and 31 healthy control subjects [control negative (CN)], with all groups matched for age. Quantitative maps of the contrast agent transfer coefficient across the BBB (Ktrans) and plasma volume (vp) were produced using Patlak analysis. Differences in Ktrans and vp were assessed with voxel-based analysis as well as in regions associated with PD pathophysiology. In addition, the volume of white matter lesions (WMLs) was obtained from T2-weighted fluid attenuation inversion recovery (FLAIR) images. Results Higher Ktrans, reflecting higher BBB leakage, was found in the PD group than in the CN group using voxel-based analysis; differences were most prominent in the posterior white matter regions. Region of interest analysis confirmed Ktrans to be significantly higher in PD than in CN, predominantly driven by differences in the substantia nigra, normal-appearing white matter, WML and the posterior cortex. WML volume was significantly higher in PD compared to CN. Ktrans values and WML volume were similar in PD and CP, suggesting a similar burden of cerebrovascular disease despite lower cardiovascular risk factors. Conclusion These results show BBB disruption in PD.
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Affiliation(s)
- Sarah Al-Bachari
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Department of Neurology, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom.,Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Josephine H Naish
- Division of Cardiovascular sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Bioxydyn Limited, Manchester, United Kingdom
| | - Geoff J M Parker
- Bioxydyn Limited, Manchester, United Kingdom.,Centre for Medical Image Computing, Department of Computer Science and Department of Neuroinflammation, University College London, London, United Kingdom
| | - Hedley C A Emsley
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Department of Neurology, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom.,Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Laura M Parkes
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, United Kingdom
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144
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Nian K, Harding IC, Herman IM, Ebong EE. Blood-Brain Barrier Damage in Ischemic Stroke and Its Regulation by Endothelial Mechanotransduction. Front Physiol 2020; 11:605398. [PMID: 33424628 PMCID: PMC7793645 DOI: 10.3389/fphys.2020.605398] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/27/2020] [Indexed: 12/21/2022] Open
Abstract
Ischemic stroke, a major cause of mortality in the United States, often contributes to disruption of the blood-brain barrier (BBB). The BBB along with its supportive cells, collectively referred to as the “neurovascular unit,” is the brain’s multicellular microvasculature that bi-directionally regulates the transport of blood, ions, oxygen, and cells from the circulation into the brain. It is thus vital for the maintenance of central nervous system homeostasis. BBB disruption, which is associated with the altered expression of tight junction proteins and BBB transporters, is believed to exacerbate brain injury caused by ischemic stroke and limits the therapeutic potential of current clinical therapies, such as recombinant tissue plasminogen activator. Accumulating evidence suggests that endothelial mechanobiology, the conversion of mechanical forces into biochemical signals, helps regulate function of the peripheral vasculature and may similarly maintain BBB integrity. For example, the endothelial glycocalyx (GCX), a glycoprotein-proteoglycan layer extending into the lumen of bloods vessel, is abundantly expressed on endothelial cells of the BBB and has been shown to regulate BBB permeability. In this review, we will focus on our understanding of the mechanisms underlying BBB damage after ischemic stroke, highlighting current and potential future novel pharmacological strategies for BBB protection and recovery. Finally, we will address the current knowledge of endothelial mechanotransduction in BBB maintenance, specifically focusing on a potential role of the endothelial GCX.
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Affiliation(s)
- Keqing Nian
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Ian C Harding
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Ira M Herman
- Department of Development, Molecular, and Chemical Biology, Tufts Sackler School of Graduate Biomedical Sciences, Boston, MA, United States.,Center for Innovations in Wound Healing Research, Tufts University School of Medicine, Boston, MA, United States
| | - Eno E Ebong
- Department of Bioengineering, Northeastern University, Boston, MA, United States.,Department of Chemical Engineering, Northeastern University, Boston, MA, United States.,Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States
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145
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Okada T, Suzuki H, Travis ZD, Zhang JH. The Stroke-Induced Blood-Brain Barrier Disruption: Current Progress of Inspection Technique, Mechanism, and Therapeutic Target. Curr Neuropharmacol 2020; 18:1187-1212. [PMID: 32484111 PMCID: PMC7770643 DOI: 10.2174/1570159x18666200528143301] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/23/2020] [Accepted: 05/23/2020] [Indexed: 02/07/2023] Open
Abstract
Stroke is one of the leading causes of mortality and morbidity worldwide. The blood-brain barrier (BBB) is a characteristic structure of microvessel within the brain. Under normal physiological conditions, the BBB plays a role in the prevention of harmful substances entering into the brain parenchyma within the central nervous system. However, stroke stimuli induce the breakdown of BBB leading to the influx of cytotoxic substances, vasogenic brain edema, and hemorrhagic transformation. Therefore, BBB disruption is a major complication, which needs to be addressed in order to improve clinical outcomes in stroke. In this review, we first discuss the structure and function of the BBB. Next, we discuss the progress of the techniques utilized to study BBB breakdown in in-vitro and in-vivo studies, along with biomarkers and imaging techniques in clinical settings. Lastly, we highlight the mechanisms of stroke-induced neuroinflammation and apoptotic process of endothelial cells causing BBB breakdown, and the potential therapeutic targets to protect BBB integrity after stroke. Secondary products arising from stroke-induced tissue damage provide transformation of myeloid cells such as microglia and macrophages to pro-inflammatory phenotype followed by further BBB disruption via neuroinflammation and apoptosis of endothelial cells. In contrast, these myeloid cells are also polarized to anti-inflammatory phenotype, repairing compromised BBB. Therefore, therapeutic strategies to induce anti-inflammatory phenotypes of the myeloid cells may protect BBB in order to improve clinical outcomes of stroke patients.
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Affiliation(s)
- Takeshi Okada
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219,
11041 Campus St, Loma Linda, CA 92354, USA,Department of Neurosurgery, Mie University Graduate School of Medicine, Mie, Japan, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
| | - Hidenori Suzuki
- Department of Neurosurgery, Mie University Graduate School of Medicine, Mie, Japan, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
| | - Zachary D Travis
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219,
11041 Campus St, Loma Linda, CA 92354, USA,Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA, USA , Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354, USA
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219,
11041 Campus St, Loma Linda, CA 92354, USA,Department of Anesthesiology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354, USA,Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354, USA
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146
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Levenberg K, Hajnal A, George DR, Saunders EFH. Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder. Med Hypotheses 2020; 146:110433. [PMID: 33317848 DOI: 10.1016/j.mehy.2020.110433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 01/09/2023]
Abstract
Approximately 45 million people worldwide are diagnosed with bipolar disorder (BD). While there are many known risk factors and models of the pathologic processes influencing BD, the exact neurologic underpinnings of BD are unknown. We attempt to integrate the existing literature and create a unifying hypothesis regarding the pathophysiology of BD with the hope that a concrete model may potentially facilitate more specific diagnosis, prevention, and treatment of BD in the future. We hypothesize that dysfunctional signaling from the parvocellular neurons of the paraventricular hypothalamic nucleus (PVN) results in the clinical presentation of BD. Functional damage to this nucleus and its signaling pathways may be mediated by myriad factors (e.g. immune dysregulation and auto-immune processes, polygenetic variation, dysfunctional interhemispheric connections, and impaired or overactivated hypothalamic axes) which could help explain the wide variety of clinical presentations along the BD spectrum. The neurons of the PVN regulate ultradian rhythms, which are observed in cyclic variations in healthy individuals, and mediate changes in functional hemispheric lateralization. Theoretically, dysfunctional PVN signaling results in prolonged functional hemispheric dominance. In this model, prolonged right hemispheric dominance leads to depressive symptoms, whereas left hemispheric dominance correlated to the clinical picture of mania. Subsequently, physiologic processes that increase signaling through the PVN (hypothalamic-pituitaryadrenal axis, hypothalamic- pituitary-gonadal axis, and hypothalamic-pituitary-thyroid axis activity, suprachiasmatic nucleus pathways) as well as, neuro-endocrine induced excito-toxicity, auto-immune and inflammatory flairs may induce mood episodes in susceptible individuals. Potentially, ultradian rhythms slowing with age, in combination with changes in hypothalamic axes and maturation of neural circuitry, accounts for BD clinically presenting more frequently in young adulthood than later in life.
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Affiliation(s)
- Kate Levenberg
- College of Medicine, Penn State University College of Medicine, State College, USA.
| | - Andras Hajnal
- Neural & Behavioral Sciences, Penn State University College of Medicine, State College, USA
| | - Daniel R George
- Department of Humanities, Penn State University College of Medicine, Hershey, USA
| | - Erika F H Saunders
- Psychiatry and Behavioral Health, Penn State University College of Medicine, State College, USA
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147
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Activation of endothelial Wnt/β-catenin signaling by protective astrocytes repairs BBB damage in ischemic stroke. Prog Neurobiol 2020; 199:101963. [PMID: 33249091 DOI: 10.1016/j.pneurobio.2020.101963] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 01/04/2023]
Abstract
The role of astrocytes in dysregulation of blood-brain barrier (BBB) function following ischemic stroke is not well understood. Here, we investigate the effects of restoring the repair properties of astrocytes on the BBB after ischemic stroke. Mice deficient for NHE1, a pH-sensitive Na+/H+ exchanger 1, in astrocytes have reduced BBB permeability after ischemic stroke, increased angiogenesis and cerebral blood flow perfusion, in contrast to wild-type mice. Bulk RNA-sequencing transcriptome analysis of purified astrocytes revealed that ∼177 genes were differentially upregulated in mutant astrocytes, with Wnt7a mRNA among the top genes. Using a Wnt reporter line, we confirmed that the pathway was upregulated in cerebral vessels of mutant mice after ischemic stroke. However, administration of the Wnt/β-catenin inhibitor, XAV-939, blocked the reparative effects of Nhe1-deficient astrocytes. Thus, astrocytes lacking pH-sensitive NHE1 protein are transformed from injurious to "protective" by inducing Wnt production to promote BBB repair after ischemic stroke.
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148
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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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149
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Lana D, Ugolini F, Giovannini MG. An Overview on the Differential Interplay Among Neurons-Astrocytes-Microglia in CA1 and CA3 Hippocampus in Hypoxia/Ischemia. Front Cell Neurosci 2020; 14:585833. [PMID: 33262692 PMCID: PMC7686560 DOI: 10.3389/fncel.2020.585833] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/09/2020] [Indexed: 12/13/2022] Open
Abstract
Neurons have been long regarded as the basic functional cells of the brain, whereas astrocytes and microglia have been regarded only as elements of support. However, proper intercommunication among neurons-astrocytes-microglia is of fundamental importance for the functional organization of the brain. Perturbation in the regulation of brain energy metabolism not only in neurons but also in astrocytes and microglia may be one of the pathophysiological mechanisms of neurodegeneration, especially in hypoxia/ischemia. Glial activation has long been considered detrimental for survival of neurons, but recently it appears that glial responses to an insult are not equal but vary in different brain areas. In this review, we first take into consideration the modifications of the vascular unit of the glymphatic system and glial metabolism in hypoxic conditions. Using the method of triple-labeling fluorescent immunohistochemistry coupled with confocal microscopy (TIC), we recently studied the interplay among neurons, astrocytes, and microglia in chronic brain hypoperfusion. We evaluated the quantitative and morpho-functional alterations of the neuron-astrocyte-microglia triads comparing the hippocampal CA1 area, more vulnerable to ischemia, to the CA3 area, less vulnerable. In these contiguous and interconnected areas, in the same experimental hypoxic conditions, astrocytes and microglia show differential, finely regulated, region-specific reactivities. In both areas, astrocytes and microglia form triad clusters with apoptotic, degenerating neurons. In the neuron-astrocyte-microglia triads, the cell body of a damaged neuron is infiltrated and bisected by branches of astrocyte that create a microscar around it while a microglial cell phagocytoses the damaged neuron. These coordinated actions are consistent with the scavenging and protective activities of microglia. In hypoxia, the neuron-astrocyte-microglia triads are more numerous in CA3 than in CA1, further indicating their protective effects. These data, taken from contiguous and interconnected hippocampal areas, demonstrate that glial response to the same hypoxic insult is not equal but varies significantly. Understanding the differences of glial reactivity is of great interest to explain the differential susceptibility of hippocampal areas to hypoxia/ischemia. Further studies may evidence the differential reactivity of glia in different brain areas, explaining the higher or lower sensitivity of these areas to different insults and whether glia may represent a target for future therapeutic interventions.
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Affiliation(s)
- Daniele Lana
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Filippo Ugolini
- Department of Health Sciences, Section of Anatomopathology, University of Florence, Florence, Italy
| | - Maria G Giovannini
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
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150
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Toth AE, Holst MR, Nielsen MS. Vesicular Transport Machinery in Brain Endothelial Cells: What We Know and What We Do not. Curr Pharm Des 2020; 26:1405-1416. [PMID: 32048959 DOI: 10.2174/1381612826666200212113421] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/03/2019] [Indexed: 12/20/2022]
Abstract
The vesicular transport machinery regulates numerous essential functions in cells such as cell polarity, signaling pathways, and the transport of receptors and their cargoes. From a pharmaceutical perspective, vesicular transport offers avenues to facilitate the uptake of therapeutic agents into cells and across cellular barriers. In order to improve receptor-mediated transcytosis of biologics across the blood-brain barrier and into the diseased brain, a detailed understanding of intracellular transport mechanisms is essential. The vesicular transport machinery is a highly complex network and involves an array of protein complexes, cytosolic adaptor proteins, and the subcellular structures of the endo-lysosomal system. The endo-lysosomal system includes several types of vesicular entities such as early, late, and recycling endosomes, exosomes, ectosomes, retromer-coated vesicles, lysosomes, trans-endothelial channels, and tubules. While extensive research has been done on the trafficking system in many cell types, little is known about vesicular trafficking in brain endothelial cells. Consequently, assumptions on the transport system in endothelial cells are based on findings in polarised epithelial cells, although recent studies have highlighted differences in the endothelial system. This review highlights aspects of the vesicular trafficking machinery in brain endothelial cells, including recent findings, limitations, and opportunities for further studies.
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Affiliation(s)
- Andrea E Toth
- Department of Biomedicine, Faculty of Health, Aarhus University, Høegh-Guldberg Gade 10, 8000 Aarhus C, Denmark
| | - Mikkel R Holst
- Department of Biomedicine, Faculty of Health, Aarhus University, Høegh-Guldberg Gade 10, 8000 Aarhus C, Denmark
| | - Morten S Nielsen
- Department of Biomedicine, Faculty of Health, Aarhus University, Høegh-Guldberg Gade 10, 8000 Aarhus C, Denmark
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