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Yang X, Li W, Ding M, Liu KJ, Qi Z, Zhao Y. Contribution of zinc accumulation to ischemic brain injury and its mechanisms about oxidative stress, inflammation, and autophagy: an update. Metallomics 2024; 16:mfae012. [PMID: 38419293 DOI: 10.1093/mtomcs/mfae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 02/27/2024] [Indexed: 03/02/2024]
Abstract
Ischemic stroke is a leading cause of death and disability worldwide, and presently, there is no effective neuroprotective therapy. Zinc is an essential trace element that plays important physiological roles in the central nervous system. Free zinc concentration is tightly regulated by zinc-related proteins in the brain under normal conditions. Disruption of zinc homeostasis, however, has been found to play an important role in the mechanism of brain injury following ischemic stroke. A large of free zinc releases from storage sites after cerebral ischemia, which affects the functions and survival of nerve cells, including neurons, astrocytes, and microglia, resulting in cell death. Ischemia-triggered intracellular zinc accumulation also disrupts the function of blood-brain barrier via increasing its permeability, impairing endothelial cell function, and altering tight junction levels. Oxidative stress and neuroinflammation have been reported to be as major pathological mechanisms in cerebral ischemia/reperfusion injury. Studies have showed that the accumulation of intracellular free zinc could impair mitochondrial function to result in oxidative stress, and form a positive feedback loop between zinc accumulation and reactive oxygen species production, which leads to a series of harmful reactions. Meanwhile, elevated intracellular zinc leads to neuroinflammation. Recent studies also showed that autophagy is one of the important mechanisms of zinc toxicity after ischemic injury. Interrupting the accumulation of zinc will reduce cerebral ischemia injury and improve neurological outcomes. This review summarizes the role of zinc toxicity in cellular and tissue damage following cerebral ischemia, focusing on the mechanisms about oxidative stress, inflammation, and autophagy.
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Affiliation(s)
- Xueqi Yang
- Institute of Cerebrovascular Disease Research, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Beijing 100053, China
- Beijing Geriatric Medical Research Center, Beijing 100053, China
| | - Wei Li
- Institute of Cerebrovascular Disease Research, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Beijing 100053, China
- Beijing Geriatric Medical Research Center, Beijing 100053, China
| | - Mao Ding
- Institute of Cerebrovascular Disease Research, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Beijing 100053, China
| | - Ke Jian Liu
- Department of Pathology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Zhifeng Qi
- Institute of Cerebrovascular Disease Research, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Beijing 100053, China
- Beijing Geriatric Medical Research Center, Beijing 100053, China
| | - Yongmei Zhao
- Institute of Cerebrovascular Disease Research, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Beijing 100053, China
- Beijing Geriatric Medical Research Center, Beijing 100053, China
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2
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Buxton RB. Thermodynamic limitations on brain oxygen metabolism: physiological implications. J Physiol 2024; 602:683-712. [PMID: 38349000 DOI: 10.1113/jp284358] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/03/2024] [Indexed: 02/20/2024] Open
Abstract
Recent thermodynamic modelling indicates that maintaining the brain tissue ratio of O2 to CO2 (abbreviated tissue O2 /CO2 ) is critical for preserving the entropy increase available from oxidative metabolism of glucose, with a fall of that available entropy leading to a reduction of the phosphorylation potential and impairment of brain energy metabolism. This provides a novel perspective for understanding physiological responses under different conditions in terms of preserving tissue O2 /CO2 . To enable estimation of tissue O2 /CO2 in the human brain, a detailed mathematical model of O2 and CO2 transport was developed, and applied to reported physiological responses to different challenges, asking: how well is tissue O2 /CO2 preserved? Reported experimental results for increased neural activity, hypercapnia and hypoxia due to high altitude are consistent with preserving tissue O2 /CO2 . The results highlight two physiological mechanisms that control tissue O2 /CO2 : cerebral blood flow, which modulates tissue O2 ; and ventilation rate, which modulates tissue CO2 . The hypoxia modelling focused on humans at high altitude, including acclimatized lowlanders and Tibetan and Andean adapted populations, with a primary finding that decreasing CO2 by increasing ventilation rate is more effective for preserving tissue O2 /CO2 than increasing blood haemoglobin content to maintain O2 delivery to tissue. This work focused on the function served by particular physiological responses, and the underlying mechanisms require further investigation. The modelling provides a new framework and perspective for understanding how blood flow and other physiological factors support energy metabolism in the brain under a wide range of conditions. KEY POINTS: Thermodynamic modelling indicates that preserving the O2 /CO2 ratio in brain tissue is critical for preserving the entropy change available from oxidative metabolism of glucose and the phosphorylation potential underlying energy metabolism. A detailed model of O2 and CO2 transport was developed to allow estimation of the tissue O2 /CO2 ratio in the human brain in different physiological states. Reported experimental results during hypoxia, hypercapnia and increased oxygen metabolic rate in response to increased neural activity are consistent with maintaining brain tissue O2 /CO2 ratio. The hypoxia modelling of high-altitude acclimatization and adaptation in humans demonstrates the critical role of reducing CO2 with increased ventilation for preserving tissue O2 /CO2 . Preservation of tissue O2 /CO2 provides a novel perspective for understanding the function of observed physiological responses under different conditions in terms of preserving brain energy metabolism, although the mechanisms underlying these functions are not well understood.
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Affiliation(s)
- Richard B Buxton
- Center for Functional Magnetic Resonance Imaging, Department of Radiology, University of California, San Diego, California, USA
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3
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Galizzi G, Di Carlo M. Mitochondrial DNA and Inflammation in Alzheimer's Disease. Curr Issues Mol Biol 2023; 45:8586-8606. [PMID: 37998717 PMCID: PMC10670154 DOI: 10.3390/cimb45110540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/15/2023] [Accepted: 10/20/2023] [Indexed: 11/25/2023] Open
Abstract
Mitochondrial dysfunction and neuroinflammation are implicated in the pathogenesis of most neurodegenerative diseases, such as Alzheimer's disease (AD). In fact, although a growing number of studies show crosstalk between these two processes, there remain numerous gaps in our knowledge of the mechanisms involved, which requires further clarification. On the one hand, mitochondrial dysfunction may lead to the release of mitochondrial damage-associated molecular patterns (mtDAMPs) which are recognized by microglial immune receptors and contribute to neuroinflammation progression. On the other hand, inflammatory molecules released by glial cells can influence and regulate mitochondrial function. A deeper understanding of these mechanisms may help identify biomarkers and molecular targets useful for the treatment of neurodegenerative diseases. This review of works published in recent years is focused on the description of the mitochondrial contribution to neuroinflammation and neurodegeneration, with particular attention to mitochondrial DNA (mtDNA) and AD.
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Affiliation(s)
- Giacoma Galizzi
- Institute for Research and Biomedical Innovation (IRIB), National Research Council (CNR), Via Ugo La Malfa, 153-90146 Palermo, Italy;
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Palumbo L, Carinci M, Guarino A, Asth L, Zucchini S, Missiroli S, Rimessi A, Pinton P, Giorgi C. The NLRP3 Inflammasome in Neurodegenerative Disorders: Insights from Epileptic Models. Biomedicines 2023; 11:2825. [PMID: 37893198 PMCID: PMC10604217 DOI: 10.3390/biomedicines11102825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Neuroinflammation represents a dynamic process of defense and protection against the harmful action of infectious agents or other detrimental stimuli in the central nervous system (CNS). However, the uncontrolled regulation of this physiological process is strongly associated with serious dysfunctional neuronal issues linked to the progression of CNS disorders. Moreover, it has been widely demonstrated that neuroinflammation is linked to epilepsy, one of the most prevalent and serious brain disorders worldwide. Indeed, NLRP3, one of the most well-studied inflammasomes, is involved in the generation of epileptic seizures, events that characterize this pathological condition. In this context, several pieces of evidence have shown that the NLRP3 inflammasome plays a central role in the pathophysiology of mesial temporal lobe epilepsy (mTLE). Based on an extensive review of the literature on the role of NLRP3-dependent inflammation in epilepsy, in this review we discuss our current understanding of the connection between NLRP3 inflammasome activation and progressive neurodegeneration in epilepsy. The goal of the review is to cover as many of the various known epilepsy models as possible, providing a broad overview of the current literature. Lastly, we also propose some of the present therapeutic strategies targeting NLRP3, aiming to provide potential insights for future studies.
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Affiliation(s)
- Laura Palumbo
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (L.P.); (M.C.); (S.M.); (A.R.); (P.P.)
| | - Marianna Carinci
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (L.P.); (M.C.); (S.M.); (A.R.); (P.P.)
| | - Annunziata Guarino
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara 70, 44121 Ferrara, Italy; (A.G.); (L.A.); (S.Z.)
| | - Laila Asth
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara 70, 44121 Ferrara, Italy; (A.G.); (L.A.); (S.Z.)
| | - Silvia Zucchini
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara 70, 44121 Ferrara, Italy; (A.G.); (L.A.); (S.Z.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy
| | - Sonia Missiroli
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (L.P.); (M.C.); (S.M.); (A.R.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (L.P.); (M.C.); (S.M.); (A.R.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy
- Center of Research for Innovative Therapies in Cystic Fibrosis, University of Ferrara, 44121 Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (L.P.); (M.C.); (S.M.); (A.R.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy
- Center of Research for Innovative Therapies in Cystic Fibrosis, University of Ferrara, 44121 Ferrara, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy; (L.P.); (M.C.); (S.M.); (A.R.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy
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5
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Ahn JJ, Islam Y, Clarkson-Paredes C, Karl MT, Miller RH. B cell depletion modulates glial responses and enhances blood vessel integrity in a model of multiple sclerosis. Neurobiol Dis 2023; 187:106290. [PMID: 37709209 DOI: 10.1016/j.nbd.2023.106290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023] Open
Abstract
Multiple sclerosis (MS) is characterized by a compromised blood-brain barrier (BBB) resulting in central nervous system (CNS) entry of peripheral lymphocytes, including T cells and B cells. While T cells have largely been considered the main contributors to neuroinflammation in MS, the success of B cell depletion therapies suggests an important role for B cells in MS pathology. Glial cells in the CNS are essential components in both disease progression and recovery, raising the possibility that they represent targets for B cell functions. Here, we examine astrocyte and microglia responses to B cell depleting treatments in an animal model of MS, experimental autoimmune encephalomyelitis (EAE). B cell depleted EAE animals had markedly reduced disease severity and myelin damage accompanied by reduced microglia and astrocyte reactivity 20 days after symptom onset. To identify potential initial mechanisms mediating functional changes following B cell depletion, astrocyte and microglia transcriptomes were analyzed 3 days following B cell depletion. In control EAE animals, transcriptomic analysis revealed astrocytic inflammatory pathways were activated and microglial influence on neuronal function were inhibited. Following B cell depletion, initial functional recovery was associated with an activation of astrocytic pathways linked with restoration of neurovascular integrity and of microglial pathways associated with neuronal function. These studies reveal an important role for B cell depletion in influencing glial function and CNS vasculature in an animal model of MS.
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Affiliation(s)
- Julie J Ahn
- The George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, Ross Hall, 2300 I St NW, Washington, DC 20037, United States of America
| | - Yusra Islam
- The George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, Ross Hall, 2300 I St NW, Washington, DC 20037, United States of America
| | - Cheryl Clarkson-Paredes
- The George Washington University School of Medicine and Health Sciences, Nanofabrication and Imaging Center, Science and Engineering Hall, 800 22(nd) St NW, Washington, DC 20037, United States of America
| | - Molly T Karl
- The George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, Ross Hall, 2300 I St NW, Washington, DC 20037, United States of America
| | - Robert H Miller
- The George Washington University School of Medicine and Health Sciences, Department of Anatomy and Cell Biology, Ross Hall, 2300 I St NW, Washington, DC 20037, United States of America.
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6
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Brazhe A, Verisokin A, Verveyko D, Postnov D. Astrocytes: new evidence, new models, new roles. Biophys Rev 2023; 15:1303-1333. [PMID: 37975000 PMCID: PMC10643736 DOI: 10.1007/s12551-023-01145-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 09/08/2023] [Indexed: 11/19/2023] Open
Abstract
Astrocytes have been in the limelight of active research for about 3 decades now. Over this period, ideas about their function and role in the nervous system have evolved from simple assistance in energy supply and homeostasis maintenance to a complex informational and metabolic hub that integrates data on local neuronal activity, sensory and arousal context, and orchestrates many crucial processes in the brain. Rapid progress in experimental techniques and data analysis produces a growing body of data, which can be used as a foundation for formulation of new hypotheses, building new refined mathematical models, and ultimately should lead to a new level of understanding of the contribution of astrocytes to the cognitive tasks performed by the brain. Here, we highlight recent progress in astrocyte research, which we believe expands our understanding of how low-level signaling at a cellular level builds up to processes at the level of the whole brain and animal behavior. We start our review with revisiting data on the role of noradrenaline-mediated astrocytic signaling in locomotion, arousal, sensory integration, memory, and sleep. We then briefly review astrocyte contribution to the regulation of cerebral blood flow regulation, which is followed by a discussion of biophysical mechanisms underlying astrocyte effects on different brain processes. The experimental section is closed by an overview of recent experimental techniques available for modulation and visualization of astrocyte dynamics. We then evaluate how the new data can be potentially incorporated into the new mathematical models or where and how it already has been done. Finally, we discuss an interesting prospect that astrocytes may be key players in important processes such as the switching between sleep and wakefulness and the removal of toxic metabolites from the brain milieu.
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Affiliation(s)
- Alexey Brazhe
- Department of Biophysics, Biological Faculty, Lomonosov Moscow State University, Leninskie Gory, 1/24, Moscow, 119234 Russia
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry RAS, GSP-7, Miklukho-Maklay Str., 16/10, Moscow, 117997 Russia
| | - Andrey Verisokin
- Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, Kursk, 305000 Russia
| | - Darya Verveyko
- Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, Kursk, 305000 Russia
| | - Dmitry Postnov
- Department of Optics and Biophotonics, Saratov State University, Astrakhanskaya st., 83, Saratov, 410012 Russia
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7
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Xue S, Zhou X, Yang ZH, Si XK, Sun X. Stroke-induced damage on the blood-brain barrier. Front Neurol 2023; 14:1248970. [PMID: 37840921 PMCID: PMC10569696 DOI: 10.3389/fneur.2023.1248970] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/08/2023] [Indexed: 10/17/2023] Open
Abstract
The blood-brain barrier (BBB) is a functional phenotype exhibited by the neurovascular unit (NVU). It is maintained and regulated by the interaction between cellular and non-cellular matrix components of the NVU. The BBB plays a vital role in maintaining the dynamic stability of the intracerebral microenvironment as a barrier layer at the critical interface between the blood and neural tissues. The large contact area (approximately 20 m2/1.3 kg brain) and short diffusion distance between neurons and capillaries allow endothelial cells to dominate the regulatory role. The NVU is a structural component of the BBB. Individual cells and components of the NVU work together to maintain BBB stability. One of the hallmarks of acute ischemic stroke is the disruption of the BBB, including impaired function of the tight junction and other molecules, as well as increased BBB permeability, leading to brain edema and a range of clinical symptoms. This review summarizes the cellular composition of the BBB and describes the protein composition of the barrier functional junction complex and the mechanisms regulating acute ischemic stroke-induced BBB disruption.
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Affiliation(s)
| | | | | | | | - Xin Sun
- Stroke Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China
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8
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Salcedo-Arellano MJ, Johnson MD, McLennan YA, Hwang YH, Juarez P, McBride EL, Pantoja AP, Durbin-Johnson B, Tassone F, Hagerman RJ, Martínez-Cerdeño V. Brain Metabolomics in Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS). Cells 2023; 12:2132. [PMID: 37681866 PMCID: PMC10487256 DOI: 10.3390/cells12172132] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 08/08/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
The course of pathophysiological mechanisms involved in fragile X-associated tremor/ataxia syndrome (FXTAS) remains largely unknown. Previous proteomics and metabolomics studies conducted in blood samples collected from FMR1 premutation carriers with FXTAS reported abnormalities in energy metabolism, and precursors of gluconeogenesis showed significant changes in plasma expression levels in FMR1 premutation carriers who developed FXTAS. We conducted an analysis of postmortem human brain tissues from 44 donors, 25 brains with FXTAS, and 19 matched controls. We quantified the metabolite relative abundance in the inferior temporal gyrus and the cerebellum using untargeted mass spectrometry (MS)-based metabolomics. We investigated how the metabolite type and abundance relate to the number of cytosine-guanine-guanine (CGG) repeats, to markers of neurodegeneration, and to the symptoms of FXTAS. A metabolomic analysis identified 191 primary metabolites, the data were log-transformed and normalized prior to the analysis, and the relative abundance was compared between the groups. The changes in the relative abundance of a set of metabolites were region-specific with some overlapping results; 22 metabolites showed alterations in the inferior temporal gyrus, while 21 showed differences in the cerebellum. The relative abundance of cytidine was decreased in the inferior temporal gyrus, and a lower abundance was found in the cases with larger CGG expansions; oleamide was significantly decreased in the cerebellum. The abundance of 11 metabolites was influenced by changes in the CGG repeat number. A histological evaluation found an association between the presence of microhemorrhages in the inferior temporal gyrus and a lower abundance of 2,5-dihydroxypyrazine. Our study identified alterations in the metabolites involved in the oxidative-stress response and bioenergetics in the brains of individuals with FXTAS. Significant changes in the abundance of cytidine and oleamide suggest their potential as biomarkers and therapeutic targets for FXTAS.
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Affiliation(s)
- Maria Jimena Salcedo-Arellano
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA 95616, USA; (M.J.S.-A.); (F.T.); (R.J.H.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
| | - Michael D. Johnson
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
| | - Yingratana A. McLennan
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
| | - Ye Hyun Hwang
- Department of Biochemistry and Molecular Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (Y.H.H.); (F.T.)
| | - Pablo Juarez
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
| | - Erin Lucille McBride
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
| | - Adriana P. Pantoja
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
| | - Blythe Durbin-Johnson
- Division of Biostatistics, Department of Public Health Sciences, UC Davis School of Medicine, Sacramento, CA 95817, USA;
| | - Flora Tassone
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA 95616, USA; (M.J.S.-A.); (F.T.); (R.J.H.); (V.M.-C.)
- Department of Biochemistry and Molecular Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (Y.H.H.); (F.T.)
| | - Randi J. Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA 95616, USA; (M.J.S.-A.); (F.T.); (R.J.H.); (V.M.-C.)
- Department of Pediatrics, UC Davis School of Medicine, Sacramento, CA 95817, USA;
| | - Verónica Martínez-Cerdeño
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA 95616, USA; (M.J.S.-A.); (F.T.); (R.J.H.); (V.M.-C.)
- Institute for Pediatric Regenerative Medicine at Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; (M.J.S.-A.); (M.D.J.); (Y.A.M.); (P.J.); (E.L.M.); (A.P.P.); (V.M.-C.)
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9
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Tice C, Zhao H, Langford D. Single nucleotide polymorphisms in aquaporin-4 associate with cognitive impairment status in people with HIV. J Neurovirol 2023; 29:258-271. [PMID: 37191905 DOI: 10.1007/s13365-023-01126-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/20/2023] [Accepted: 03/13/2023] [Indexed: 05/17/2023]
Abstract
Neurocognitive impairments are more frequent in people with HIV (PWH) compared to their uninfected counterparts. HIV-associated neurocognitive disorder (HAND) is a spectrum disorder and up to 50% of PWH are reported to suffer from HAND. Altered waste clearance from the brain, chronic neuroinflammation and impaired metabolic processes may contribute to abnormal aging in PWH and are more common among those who suffer from HAND. Thus, it is important to identify earlier predictors for development of HAND. A key contributor to cognitive impairment in HIV and in Alzheimer's disease (AD) is formation and accumulation of aberrant proteins including hyperphosphorylated Tau (pTau). Previous data from AD and traumatic brain injury studies report that impaired waste clearance from the brain contributes in part to cognitive impairments. Evidence suggests that the aquaporin 4 (aqp4) gene may have an important role in waste clearance from the brain as single nucleotide polymorphisms (SNPs) in aqp4 have been reported to associate with changes in cognitive decline in AD patients. Given some similarities between HAND and AD, we assessed potential associations of several aqp4 SNPS with cognitive impairment in PWH. Our data show that homozygous carriers of the minor allele in SNPs rs3875089 and rs3763040 had significantly lower neuropsychological test Z-scores in multiple domains compared to the other genotypes. Interestingly, this decrease in Z-scores was only observed in PWH and not in HIV-control participants. Conversely, homozygosity of the minor allele of rs335929 associated with better executive function in PWH. Based on these data, tracking large cohorts of PWH to determine if the presence of these SNPs associate with cognitive changes during disease progression is of interest. Furthermore, screening PWH for SNPs that may be associated with cognitive impairment risk after diagnosis could be considered in alignment with traditional treatment plans to potentially work on skills in areas shown to have cognitive decline with these SNPs present.
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Affiliation(s)
- Caitlin Tice
- Lewis Katz School of Medicine, Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA
| | - Huaqing Zhao
- Lewis Katz School of Medicine, Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA
| | - Dianne Langford
- Lewis Katz School of Medicine, Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA.
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10
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Shyam R, Patel ML, Solanki M, Sachan R, Ali W. Correlation of C-reactive Protein with Delirium in Obstetrics Intensive Care Unit: A Tertiary Center Experience. Indian J Crit Care Med 2023; 27:315-321. [PMID: 37214122 PMCID: PMC10196652 DOI: 10.5005/jp-journals-10071-24455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 03/27/2023] [Indexed: 05/24/2023] Open
Abstract
Background Delirium is a neuropsychiatric illness. It affects critically ill patients on ventilator and increases mortality. The aim of this study was to evaluate the association of C-reactive protein (CRP) level with delirium in critically obstetrics women and its role in prediction of delirium. Materials and methods Arospective observational study was conducted in the intensive care unit (ICU), and the duration of study was one year. Total 145 subjects were recruited, 33 patients were excluded, and 112 subjects were studied. For study, group A (n = 36) includes critically ill obstetric women who had delirium on admission; group B (n = 37) includes critically ill obstetric women who developed delirium within 7 days; and group C (n = 39) that includes critically ill obstetric women who did not develop delirium after follow-up of 7 days was served as control. Disease severity was assessed by using acute physiologic assessment and chronic health evaluation (APACHE) II score, and Richmond Agitation-Sedation Scale (RASS) was used to assess awakeness. In awake patients (RASS of ≥3), delirium was assessed by the use of confusion assessment method for ICU tools. C-reactive protein measured by particle enhanced turbidimetric immunoassay-two point kinetic method. Results The mean ages of group A, B, and C were 26.44 ± 4.72, 27.46 ± 4.97, and 28.26 ± 5.67 years, respectively. C-reactive protein levels on the day of delirium development (group B) were found to be significantly higher than day 1 CRP levels of groups A and C. The mean Global Attentiveness Rating (GAR) was significantly lower in groups A and B as compared to that in group C (p < 0.001). On evaluating the correlation of CRP with GAR, it was found to be inverse and mild in strength for the correlation between CRP and GAR (r = -0.403, p < 0.001). At a cut-off value of >181 mg/L, CRP had sensitivity of 93.2% and specificity of 69.2%. The positive predictive value was 85% and the negative predictive value was 84.4% that differentiate delirium from non-delirium. Conclusion C-reactive protein is a useful tool for screening and prediction of delirium in critically ill obstetric patients. How to cite this article Shyam R, Patel ML, Solanki M, Sachan R, Ali W. Correlation of C-reactive Protein with Delirium in Obstetrics Intensive Care Unit: A Tertiary Center Experience. Indian J Crit Care Med 2023;27(5):315-321.
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Affiliation(s)
- Radhey Shyam
- Department of Geriatric Mental Health and Critical Care, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - Munna Lal Patel
- Department of Internal Medicine, King George Medical University, Lucknow, Uttar Pradesh, India
| | - Monam Solanki
- Department of Obstetrics and Gynecology, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - Rekha Sachan
- Department of Obstetrics and Gynecology, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - Wahid Ali
- Department of Pathology, King George's Medical University, Lucknow, Uttar Pradesh, India
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11
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Hazra R, Novelli EM, Hu X. Astrocytic mitochondrial frataxin-A promising target for ischemic brain injury. CNS Neurosci Ther 2023; 29:783-788. [PMID: 36550598 PMCID: PMC9928550 DOI: 10.1111/cns.14068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/30/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
In the ischemic brain, hypoxia leads to mitochondrial dysfunction, insufficient energy production, and astrocyte activation. Yet, most studies investigating mitochondrial dysfunction in cerebral ischemia have focused exclusively on neurons. This review will highlight the importance of the morphological, molecular, and functional heterogeneity of astrocytes in their role in brain injuries and explore how activated astrocytes exhibit calcium imbalance, reactive oxygen species overproduction, and apoptosis. In addition, special focus will be given to the role of the mitochondrial protein frataxin in activated astrocytes during ischemia and its putative role in the pharmacological management of cerebral ischemia.
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Affiliation(s)
- Rimi Hazra
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Enrico M Novelli
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Xiaoming Hu
- Center of Cerebrovascular Disease Research, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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12
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Lipid mediators generated by the cytochrome P450—Epoxide hydrolase pathway. ADVANCES IN PHARMACOLOGY 2023; 97:327-373. [DOI: 10.1016/bs.apha.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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13
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Asante I, Louie S, Yassine HN. Uncovering mechanisms of brain inflammation in Alzheimer's disease with APOE4: Application of single cell-type lipidomics. Ann N Y Acad Sci 2022; 1518:84-105. [PMID: 36200578 PMCID: PMC10092192 DOI: 10.1111/nyas.14907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A chronic state of unresolved inflammation in Alzheimer's disease (AD) is intrinsically involved with the remodeling of brain lipids. This review highlights the effect of carrying the apolipoprotein E ε4 allele (APOE4) on various brain cell types in promoting an unresolved inflammatory state. Among its pleotropic effects on brain lipids, we focus on APOE4's activation of Ca2+ -dependent phospholipase A2 (cPLA2) and its effects on arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid signaling cascades in the brain. During the process of neurodegeneration, various brain cell types, such as astrocytes, microglia, and neurons, together with the neurovascular unit, develop distinct inflammatory phenotypes that impact their functions and have characteristic lipidomic fingerprints. We propose that lipidomic phenotyping of single cell-types harvested from brains differing by age, sex, disease severity stage, and dietary and genetic backgrounds can be employed to probe mechanisms of neurodegeneration. A better understanding of the brain cellular inflammatory/lipidomic response promises to guide the development of nutritional and drug interventions for AD dementia.
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Affiliation(s)
- Isaac Asante
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Stan Louie
- School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Hussein N Yassine
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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14
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Castellanos DB, Martín-Jiménez CA, Pinzón A, Barreto GE, Padilla-González GF, Aristizábal A, Zuluaga M, González Santos J. Metabolomic Analysis of Human Astrocytes in Lipotoxic Condition: Potential Biomarker Identification by Machine Learning Modeling. Biomolecules 2022; 12:biom12070986. [PMID: 35883542 PMCID: PMC9313230 DOI: 10.3390/biom12070986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/15/2022] [Accepted: 06/27/2022] [Indexed: 02/04/2023] Open
Abstract
The association between neurodegenerative diseases (NDs) and obesity has been well studied in recent years. Obesity is a syndrome of multifactorial etiology characterized by an excessive accumulation and release of fatty acids (FA) in adipose and non-adipose tissue. An excess of FA generates a metabolic condition known as lipotoxicity, which triggers pathological cellular and molecular responses, causing dysregulation of homeostasis and a decrease in cell viability. This condition is a hallmark of NDs, and astrocytes are particularly sensitive to it, given their crucial role in energy production and oxidative stress management in the brain. However, analyzing cellular mechanisms associated with these conditions represents a challenge. In this regard, metabolomics is an approach that allows biochemical analysis from the comprehensive perspective of cell physiology. This technique allows cellular metabolic profiles to be determined in different biological contexts, such as those of NDs and specific metabolic insults, including lipotoxicity. Since data provided by metabolomics can be complex and difficult to interpret, alternative data analysis techniques such as machine learning (ML) have grown exponentially in areas related to omics data. Here, we developed an ML model yielding a 93% area under the receiving operating characteristic (ROC) curve, with sensibility and specificity values of 80% and 93%, respectively. This study aimed to analyze the metabolomic profiles of human astrocytes under lipotoxic conditions to provide powerful insights, such as potential biomarkers for scenarios of lipotoxicity induced by palmitic acid (PA). In this work, we propose that dysregulation in seleno-amino acid metabolism, urea cycle, and glutamate metabolism pathways are major triggers in astrocyte lipotoxic scenarios, while increased metabolites such as alanine, adenosine, and glutamate are suggested as potential biomarkers, which, to our knowledge, have not been identified in human astrocytes and are proposed as candidates for further research and validation.
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Affiliation(s)
- Daniel Báez Castellanos
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110311, Colombia; (D.B.C.); (A.A.)
| | - Cynthia A. Martín-Jiménez
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA 30329-4208, USA;
| | - Andrés Pinzón
- Laboratorio de Bioinformática y Biología de Sistemas, Universidad Nacional de Colombia, Bogotá 111321, Colombia;
| | - George E. Barreto
- Department of Biological Sciences, University of Limerick, V94 T9PX Limerick, Ireland;
| | | | - Andrés Aristizábal
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110311, Colombia; (D.B.C.); (A.A.)
| | - Martha Zuluaga
- Escuela de Ciencias Básicas Tecnologías e Ingenierías, Universidad Nacional Abierta y a Distancia, Dosquebradas 661001, Colombia;
| | - Janneth González Santos
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110311, Colombia; (D.B.C.); (A.A.)
- Correspondence: ; Tel.: +57-60-1-3208320
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15
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del Zoppo GJ, Moskowitz MA, Nedergaard M. The Neurovascular Unit and Responses to Ischemia. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00007-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Seker FB, Fan Z, Gesierich B, Gaubert M, Sienel RI, Plesnila N. Neurovascular Reactivity in the Aging Mouse Brain Assessed by Laser Speckle Contrast Imaging and 2-Photon Microscopy: Quantification by an Investigator-Independent Analysis Tool. Front Neurol 2021; 12:745770. [PMID: 34858312 PMCID: PMC8631776 DOI: 10.3389/fneur.2021.745770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/08/2021] [Indexed: 11/13/2022] Open
Abstract
The brain has a high energy demand but little to no energy stores. Therefore, proper brain function relies on the delivery of glucose and oxygen by the cerebral vasculature. The regulation of cerebral blood flow (CBF) occurs at the level of the cerebral capillaries and is driven by a fast and efficient crosstalk between neurons and vessels, a process termed neurovascular coupling (NVC). Experimentally NVC is mainly triggered by sensory stimulation and assessed by measuring either CBF by laser Doppler fluxmetry, laser speckle contrast imaging (LSCI), intrinsic optical imaging, BOLD fMRI, near infrared spectroscopy (NIRS) or functional ultrasound imaging (fUS). Since these techniques have relatively low spatial resolution, diameters of cerebral vessels are mainly assessed by 2-photon microscopy (2-PM). Results of studies on NVC rely on stable animal physiology, high-quality data acquisition, and unbiased data analysis, criteria, which are not easy to achieve. In the current study, we assessed NVC using two different imaging modalities, i.e., LSCI and 2-PM, and analyzed our data using an investigator-independent Matlab-based analysis tool, after manually defining the area of analysis in LSCI and vessels to measure in 2-PM. By investigating NVC in 6–8 weeks, 1-, and 2-year-old mice, we found that NVC was maximal in 1-year old mice and was significantly reduced in aged mice. These findings suggest that NVC is differently affected during the aging process. Most interestingly, specifically pial arterioles, seem to be distinctly affected by the aging. The main finding of our study is that the automated analysis tool works very efficiently in terms of time and accuracy. In fact, the tool reduces the analysis time of one animal from approximately 23 h to about 2 s while basically making no mistakes. In summary, we developed an experimental workflow, which allows us to reliably measure NVC with high spatial and temporal resolution in young and aged mice and to analyze these data in an investigator-independent manner.
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Affiliation(s)
- Fatma Burcu Seker
- Institute for Stroke and Dementia Research, Munich University Hospital and University of Munich, Munich, Germany
| | - Ziyu Fan
- Institute for Stroke and Dementia Research, Munich University Hospital and University of Munich, Munich, Germany
| | - Benno Gesierich
- Institute for Stroke and Dementia Research, Munich University Hospital and University of Munich, Munich, Germany
| | - Malo Gaubert
- Institute for Stroke and Dementia Research, Munich University Hospital and University of Munich, Munich, Germany
| | - Rebecca Isabella Sienel
- Institute for Stroke and Dementia Research, Munich University Hospital and University of Munich, Munich, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Munich University Hospital and University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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17
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Potjewyd G, Kellett K, Hooper N. 3D hydrogel models of the neurovascular unit to investigate blood-brain barrier dysfunction. Neuronal Signal 2021; 5:NS20210027. [PMID: 34804595 PMCID: PMC8579151 DOI: 10.1042/ns20210027] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/16/2022] Open
Abstract
The neurovascular unit (NVU), consisting of neurons, glial cells, vascular cells (endothelial cells, pericytes and vascular smooth muscle cells (VSMCs)) together with the surrounding extracellular matrix (ECM), is an important interface between the peripheral blood and the brain parenchyma. Disruption of the NVU impacts on blood-brain barrier (BBB) regulation and underlies the development and pathology of multiple neurological disorders, including stroke and Alzheimer's disease (AD). The ability to differentiate induced pluripotent stem cells (iPSCs) into the different cell types of the NVU and incorporate them into physical models provides a reverse engineering approach to generate human NVU models to study BBB function. To recapitulate the in vivo situation such NVU models must also incorporate the ECM to provide a 3D environment with appropriate mechanical and biochemical cues for the cells of the NVU. In this review, we provide an overview of the cells of the NVU and the surrounding ECM, before discussing the characteristics (stiffness, functionality and porosity) required of hydrogels to mimic the ECM when incorporated into in vitro NVU models. We summarise the approaches available to measure BBB functionality and present the techniques in use to develop robust and translatable models of the NVU, including transwell models, hydrogel models, 3D-bioprinting, microfluidic models and organoids. The incorporation of iPSCs either without or with disease-specific genetic mutations into these NVU models provides a platform in which to study normal and disease mechanisms, test BBB permeability to drugs, screen for new therapeutic targets and drugs or to design cell-based therapies.
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Affiliation(s)
- Geoffrey Potjewyd
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, U.K
| | - Katherine A.B. Kellett
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, U.K
| | - Nigel M. Hooper
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, U.K
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance and University of Manchester, Manchester, U.K
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18
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The Blood-Brain Barrier: Much More Than a Selective Access to the Brain. Neurotox Res 2021; 39:2154-2174. [PMID: 34677787 DOI: 10.1007/s12640-021-00431-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/30/2021] [Accepted: 10/15/2021] [Indexed: 12/15/2022]
Abstract
The blood-brain barrier is a dynamic structure, collectively referred to as the neurovascular unit. It is responsible for the exchange of blood, oxygen, ions, and other molecules between the peripheral circulation and the brain compartment. It is the main entrance to the central nervous system and as such critical for the maintenance of its homeostasis. Dysfunction of the blood-brain barrier is a characteristic of several neurovascular pathologies. Moreover, physiological changes, environmental factors, nutritional habits, and psychological stress can modulate the tightness of the barrier. In this contribution, we summarize our current understanding of structure and function of this important component of the brain. We also describe the neurological deficits associated with its damage. A special emphasis is placed in the effect of the exposure to xenobiotics and pollutants in the permeability of the barrier. Finally, current protective strategies as well as the culture models to study this fascinating structure are discussed.
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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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20
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Sommonte F, Arduino I, Racaniello GF, Lopalco A, Lopedota AA, Denora N. The Complexity of the Blood-Brain Barrier and the Concept of Age-Related Brain Targeting: Challenges and Potential of Novel Solid Lipid-Based Formulations. J Pharm Sci 2021; 111:577-592. [PMID: 34469749 DOI: 10.1016/j.xphs.2021.08.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022]
Abstract
Diseases that affect the Central Nervous System (CNS) are one of the most exciting challenges of recent years, as they are ubiquitous and affect all ages. Although these disorders show different etiologies, all treatments share the same difficulty represented by the Blood-Brain Barrier (BBB). This barrier acts as a protective system of the delicate cerebral microenvironment, isolating it and making extremely arduous delivering drugs to the brain. To overtake the obstacles provided by the BBB it is essential to explore the changes that affect it, to understand how to exploit these findings in the study and design of innovative brain targeted formulations. Interestingly, the concept of age-related targeting could prove to be a winning choice, as it allows to consider the type of treatment according to the different needs and peculiarities depending on the disease and the age of onset. In this review was considered the prospective contribution of lipid-based formulations, namely Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), which have been highlighted as able to overcome some limitations of other innovative approaches, thus representing a promising strategy for the non-invasive specific treatment of CNS-related diseases.
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Affiliation(s)
- Federica Sommonte
- Department of Pharmacy - Pharmaceutical Sciences, University of Bari "Aldo Moro", 4 Orabona St., 70125, Bari, Italy
| | - Ilaria Arduino
- Department of Pharmacy - Pharmaceutical Sciences, University of Bari "Aldo Moro", 4 Orabona St., 70125, Bari, Italy
| | | | - Antonio Lopalco
- Department of Pharmacy - Pharmaceutical Sciences, University of Bari "Aldo Moro", 4 Orabona St., 70125, Bari, Italy
| | - Angela Assunta Lopedota
- Department of Pharmacy - Pharmaceutical Sciences, University of Bari "Aldo Moro", 4 Orabona St., 70125, Bari, Italy
| | - Nunzio Denora
- Department of Pharmacy - Pharmaceutical Sciences, University of Bari "Aldo Moro", 4 Orabona St., 70125, Bari, Italy.
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21
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Tarantini S, Balasubramanian P, Yabluchanskiy A, Ashpole NM, Logan S, Kiss T, Ungvari A, Nyúl-Tóth Á, Schwartzman ML, Benyo Z, Sonntag WE, Csiszar A, Ungvari Z. IGF1R signaling regulates astrocyte-mediated neurovascular coupling in mice: implications for brain aging. GeroScience 2021; 43:901-911. [PMID: 33674953 PMCID: PMC8110646 DOI: 10.1007/s11357-021-00350-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/01/2021] [Indexed: 12/13/2022] Open
Abstract
Aging is associated with a significant deficiency in circulating insulin-like growth factor-1 (IGF-1), which has an important role in the pathogenesis of age-related vascular cognitive impairment (VCI). Impairment of moment-to-moment adjustment of regional cerebral blood flow via neurovascular coupling (NVC) importantly contributes to VCI. Previous studies established a causal link between circulating IGF-1 deficiency and neurovascular dysfunction. Release of vasodilator mediators from activated astrocytes plays a key role in NVC. To determine the impact of impaired IGF-1 signaling on astrocytic function, astrocyte-mediated NVC responses were studied in a novel mouse model of astrocyte-specific knockout of IGF1R (GFAP-CreERT2/Igf1rf/f) and accelerated neurovascular aging. We found that mice with disrupted astrocytic IGF1R signaling exhibit impaired NVC responses, decreased stimulated release of the vasodilator gliotransmitter epoxy-eicosatrienoic acids (EETs), and upregulation of soluble epoxy hydrolase (sEH), which metabolizes and inactivates EETs. Collectively, our findings provide additional evidence that IGF-1 promotes astrocyte health and maintains normal NVC, protecting cognitive health.
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Affiliation(s)
- Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA.
- International Training Program in Geroscience, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
- Peggy and Charles Stephenson Cancer Center, Oklahoma City, OK, 73104, USA.
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary.
| | - Priya Balasubramanian
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Nicole M Ashpole
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Pharmacology Division, Department of BioMolecular Sciences, University of Mississippi School of Pharmacy, Oxford, MS, USA
| | - Sreemathi Logan
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Department of Rehabilitation Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA
| | - Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Anna Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
- Vascular Cognitive Impairment and Neurodegeneration Program/HCEMM, Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Michal L Schwartzman
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, NY, USA
| | - Zoltan Benyo
- Vascular Cognitive Impairment and Neurodegeneration Program/HCEMM, Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - William E Sonntag
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Peggy and Charles Stephenson Cancer Center, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
- Vascular Cognitive Impairment and Neurodegeneration Program/HCEMM, Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Reynolds Oklahoma Center on Aging, Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
- Vascular Cognitive Impairment and Neurodegeneration Program/HCEMM, Department of Translational Medicine, Semmelweis University, Budapest, Hungary
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22
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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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23
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Horton WB, Barrett EJ. Microvascular Dysfunction in Diabetes Mellitus and Cardiometabolic Disease. Endocr Rev 2021; 42:29-55. [PMID: 33125468 PMCID: PMC7846151 DOI: 10.1210/endrev/bnaa025] [Citation(s) in RCA: 111] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Indexed: 02/07/2023]
Abstract
This review takes an inclusive approach to microvascular dysfunction in diabetes mellitus and cardiometabolic disease. In virtually every organ, dynamic interactions between the microvasculature and resident tissue elements normally modulate vascular and tissue function in a homeostatic fashion. This regulation is disordered by diabetes mellitus, by hypertension, by obesity, and by dyslipidemia individually (or combined in cardiometabolic disease), with dysfunction serving as an early marker of change. In particular, we suggest that the familiar retinal, renal, and neural complications of diabetes mellitus are late-stage manifestations of microvascular injury that begins years earlier and is often abetted by other cardiometabolic disease elements (eg, hypertension, obesity, dyslipidemia). We focus on evidence that microvascular dysfunction precedes anatomic microvascular disease in these organs as well as in heart, muscle, and brain. We suggest that early on, diabetes mellitus and/or cardiometabolic disease can each cause reversible microvascular injury with accompanying dysfunction, which in time may or may not become irreversible and anatomically identifiable disease (eg, vascular basement membrane thickening, capillary rarefaction, pericyte loss, etc.). Consequences can include the familiar vision loss, renal insufficiency, and neuropathy, but also heart failure, sarcopenia, cognitive impairment, and escalating metabolic dysfunction. Our understanding of normal microvascular function and early dysfunction is rapidly evolving, aided by innovative genetic and imaging tools. This is leading, in tissues like the retina, to testing novel preventive interventions at early, reversible stages of microvascular injury. Great hope lies in the possibility that some of these interventions may develop into effective therapies.
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Affiliation(s)
- William B Horton
- Division of Endocrinology and Metabolism, Department of Medicine
| | - Eugene J Barrett
- Division of Endocrinology and Metabolism, Department of Medicine.,Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia
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24
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Pfeiffer T, Li Y, Attwell D. Diverse mechanisms regulating brain energy supply at the capillary level. Curr Opin Neurobiol 2021; 69:41-50. [PMID: 33485189 DOI: 10.1016/j.conb.2020.12.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/28/2020] [Accepted: 12/13/2020] [Indexed: 02/06/2023]
Abstract
Neural information processing depends critically on the brain's energy supply, which is provided in the form of glucose and oxygen in the blood. Regulation of this supply occurs by smooth muscle and contractile pericytes adjusting the diameter of arterioles and capillaries, respectively. Controversies exist over the relative importance of capillary and arteriolar level control, whether enzymatically generated signals or K+ ions are the dominant controller of cerebral blood flow, and the involvement of capillary endothelial cells. Here, we try to synthesise the relevant recent data into a coherent view of how brain energy supply is controlled and suggest approaches to answering key questions.
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Affiliation(s)
- Thomas Pfeiffer
- Department of Neuroscience, Physiology & Pharmacology, University College London Gower Street, London, WC1E 6BT, UK.
| | - Yuening Li
- Department of Neuroscience, Physiology & Pharmacology, University College London Gower Street, London, WC1E 6BT, UK
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London Gower Street, London, WC1E 6BT, UK.
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25
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Differential patterns of parafoveal and peripapillary vessel density in multiple sclerosis and neuromyelitis optica spectrum disorder. Mult Scler Relat Disord 2021; 49:102780. [PMID: 33508571 DOI: 10.1016/j.msard.2021.102780] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/14/2021] [Accepted: 01/16/2021] [Indexed: 12/23/2022]
Abstract
BACKGROUND To compare intraocular microvascular alterations between patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) using optical coherence tomography angiography (OCT-A). METHODS Sixty patients were included in the study, 23 MS patients (36 eyes) and 37 NMOSD patients (47 eyes), all with a history of optic neuritis (ON). All subjects underwent comprehensive ophthalmic examinations, OCT-A, and high-definition-OCT imaging. OCT-A was used to measure the vessel density of the superficial and deep retinal capillary plexus (SRCP and DRCP) in the macular area and the radial peripapillary capillary (RPC) segment. Age, spherical equivalent, and gender were adjusted for in the analyses. RESULTS Patients with NMOSD showed significantly decreased vessel density of the SRCP (average, p = 0.0007; superior, p = 0.0009; inferior, p = 0.0002) and RPC segment (average, p < 0.0001; superior, p = 0.0004; inferior, p = 0.0052; temporal, p < 0.0001; nasal, p = 0.0001) compared to the MS patients. Parafoveal and peripapillary vessel density was significantly associated with the OCT parameters in both the MS and NMOSD patients. Parafoveal and peripapillary vessel density in the MS patients was significantly associated with visual function, including visual acuity and visual field defects, whereas only peripapillary vessel density was significantly associated with visual function in the NMOSD patients. CONCLUSION We demonstrated parafoveal and peripapillary vascular alterations between MS and NMOSD patients that varied in degree and pattern. We also found associations between vessel density and structural and functional parameters in MS and NMOSD patients. Further studies are needed to facilitate a greater understanding of the pathogenesis and its association with vascular alterations in these disorders.
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26
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Muniz Santana Bastos E, Bispo da Silva A, Cerqueira Coelho PL, Pereira Borges JM, Amaral da Silva VD, Moreau da Cunha VH, Costa SL. Anti-inflammatory activity of Jatropha curcas L. in brain glial cells primary cultures. JOURNAL OF ETHNOPHARMACOLOGY 2021; 264:113201. [PMID: 32814081 DOI: 10.1016/j.jep.2020.113201] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 07/09/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Jatropha curcas L. (Euphorbiaceae), a medicinal plant known in Brazil as "Pinhão Manso", is highly adaptable, being cultivated in different tropical and subtropical regions of the world. Antimicrobial, antioxidant and antiinflammatory activities have been attributed to different parts of the plant. In the central nervous sytem (CNS), neuroinflammation is mediated by glial cells, mainly by astrocytes and microglia, a process that plays an important role in neurodegenerative diseases and other CNS disorders. In this study, we investigated the anti-inflammatory activity of the methanolic extract obtained from the leaves of J. curcas L. (MEJc) in primary cultures of glial cells submited to inflammatory stimulus. MATERIALS AND METHODS Primary cultures of glial cells obtained from the cerebral cortex of neonate Wistar rats were treated with MEJc (0.1-50,000 μg mL-1) and its fractions (FnJc) (0.1 μg mL-1) with or without lipopolysaccharide of Escherichia coli (LPS) (1 μg mL-1). Cell viability was determined with MTT test. Modifications in glial cell morphology were investigated by means of phase contrast microscopy and May-Grünwald staining. The reactivity of astrocytes and microglia were investigated with immunocytochemistry for GFAP, Iba1 and transcription factor NF-kB, as well as with Greiss reaction to determine the nitric oxide (NO) production. RESULTS MEJc at 0.1-1000 μg mL-1 was non-toxic to glial cells and the DE50 was 10.794 μg mL-1. The treatment with LPS induced the activation of astrocytes and microglia marked by morphological modifications and changes in the expression of GFAP and Iba1, as well as the increase in NF-kB expression and NO production. Treatment with MEJc inhibited the morphological modifications, changes in GFAP and Iba1 expression, and the increase in NF-kB and NO production induced by LPS. CONCLUSION This study demonstrates that the MEJc and its fractions modulate inflammatory response of astrocytes and microglia to LPS and may be considered as a potential therapeutic strategy for neuroinflammation-related diseases.
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Affiliation(s)
- Eduardo Muniz Santana Bastos
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Federal University of Bahia - Institute of Health Sciences, 40100-902, Salvador, BA, Brazil; Department of Biotechnology, Institute of Health Sciences, Federal University of Bahia, 40100-902, Salvador, BA, Brazil
| | - Alessandra Bispo da Silva
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Federal University of Bahia - Institute of Health Sciences, 40100-902, Salvador, BA, Brazil
| | - Paulo Lucas Cerqueira Coelho
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Federal University of Bahia - Institute of Health Sciences, 40100-902, Salvador, BA, Brazil
| | - Julita Maria Pereira Borges
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Federal University of Bahia - Institute of Health Sciences, 40100-902, Salvador, BA, Brazil
| | - Victor Diogenes Amaral da Silva
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Federal University of Bahia - Institute of Health Sciences, 40100-902, Salvador, BA, Brazil
| | - Vitor Hugo Moreau da Cunha
- Department of Biotechnology, Institute of Health Sciences, Federal University of Bahia, 40100-902, Salvador, BA, Brazil.
| | - Silvia Lima Costa
- Laboratory of Neurochemistry and Cell Biology, Department of Biochemistry and Biophysics, Federal University of Bahia - Institute of Health Sciences, 40100-902, Salvador, BA, Brazil.
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27
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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: 69] [Impact Index Per Article: 17.3] [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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28
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Vezzani B, Carinci M, Patergnani S, Pasquin MP, Guarino A, Aziz N, Pinton P, Simonato M, Giorgi C. The Dichotomous Role of Inflammation in the CNS: A Mitochondrial Point of View. Biomolecules 2020; 10:E1437. [PMID: 33066071 PMCID: PMC7600410 DOI: 10.3390/biom10101437] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 12/14/2022] Open
Abstract
Innate immune response is one of our primary defenses against pathogens infection, although, if dysregulated, it represents the leading cause of chronic tissue inflammation. This dualism is even more present in the central nervous system, where neuroinflammation is both important for the activation of reparatory mechanisms and, at the same time, leads to the release of detrimental factors that induce neurons loss. Key players in modulating the neuroinflammatory response are mitochondria. Indeed, they are responsible for a variety of cell mechanisms that control tissue homeostasis, such as autophagy, apoptosis, energy production, and also inflammation. Accordingly, it is widely recognized that mitochondria exert a pivotal role in the development of neurodegenerative diseases, such as multiple sclerosis, Parkinson's and Alzheimer's diseases, as well as in acute brain damage, such in ischemic stroke and epileptic seizures. In this review, we will describe the role of mitochondria molecular signaling in regulating neuroinflammation in central nervous system (CNS) diseases, by focusing on pattern recognition receptors (PRRs) signaling, reactive oxygen species (ROS) production, and mitophagy, giving a hint on the possible therapeutic approaches targeting mitochondrial pathways involved in inflammation.
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Affiliation(s)
- Bianca Vezzani
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Marianna Carinci
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Simone Patergnani
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Matteo P. Pasquin
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
| | - Annunziata Guarino
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Nimra Aziz
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Maria Cecilia Hospital, GVM Care & Research, 48033 Cotignola (RA), Italy
| | - Michele Simonato
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
- Department of BioMedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy
- School of Medicine, University Vita-Salute San Raffaele, 20132 Milan, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; (B.V.); (M.C.); (S.P.); (M.P.P.); (P.P.)
- Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, 44121 Ferrara, Italy; (A.G.); (N.A.); (M.S.)
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29
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Tice C, McDevitt J, Langford D. Astrocytes, HIV and the Glymphatic System: A Disease of Disrupted Waste Management? Front Cell Infect Microbiol 2020; 10:523379. [PMID: 33134185 PMCID: PMC7550659 DOI: 10.3389/fcimb.2020.523379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 08/19/2020] [Indexed: 12/17/2022] Open
Abstract
The discovery of the glial-lymphatic or glymphatic fluid clearance pathway in the rodent brain led researchers to search for a parallel system in humans and to question the implications of this pathway in neurodegenerative diseases. Magnetic resonance imaging studies revealed that several features of the glymphatic system may be present in humans. In both rodents and humans, this pathway promotes the exchange of interstitial fluid (ISF) and cerebrospinal fluid (CSF) through the arterial perivascular spaces into the brain parenchyma. This process is facilitated in part by aquaporin-4 (AQP4) water channels located primarily on astrocytic end feet that abut cerebral endothelial cells of the blood brain barrier. Decreased expression or mislocalization of AQP4 from astrocytic end feet results in decreased interstitial flow, thereby, promoting accumulation of extracellular waste products like hyperphosphorylated Tau (pTau). Accumulation of pTau is a neuropathological hallmark in Alzheimer's disease (AD) and is accompanied by mislocalization of APQ4 from astrocyte end feet to the cell body. HIV infection shares many neuropathological characteristics with AD. Similar to AD, HIV infection of the CNS contributes to abnormal aging with altered AQP4 localization, accumulation of pTau and chronic neuroinflammation. Up to 30% of people with HIV (PWH) suffer from HIV-associated neurocognitive disorders (HAND), and changes in AQP4 may be clinically important as a contributor to cognitive disturbances. In this review, we provide an overview and discussion of the potential contributions of NeuroHIV to glymphatic system functions by focusing on astrocytes and AQP4. Although HAND encompasses a wide range of neurocognitive impairments and levels of neuroinflammation vary among and within PWH, the potential contribution of disruption in AQP4 may be clinically important in some cases. In this review we discuss implications for possible AQP4 disruption on NeuroHIV disease trajectory and how HIV may influence AQP4 function.
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Affiliation(s)
- Caitlin Tice
- Department of Neuroscience, Lewis Katz School of Medicine, Philadelphia, PA, United States
| | - Jane McDevitt
- Department of Kinesiology, College of Public Health at Temple University, Philadelphia, PA, United States
| | - Dianne Langford
- Department of Neuroscience, Lewis Katz School of Medicine, Philadelphia, PA, United States
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30
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Diabetic Retinopathy: The Role of Mitochondria in the Neural Retina and Microvascular Disease. Antioxidants (Basel) 2020; 9:antiox9100905. [PMID: 32977483 PMCID: PMC7598160 DOI: 10.3390/antiox9100905] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy (DR), a common chronic complication of diabetes mellitus and the leading cause of vision loss in the working-age population, is clinically defined as a microvascular disease that involves damage of the retinal capillaries with secondary visual impairment. While its clinical diagnosis is based on vascular pathology, DR is associated with early abnormalities in the electroretinogram, indicating alterations of the neural retina and impaired visual signaling. The pathogenesis of DR is complex and likely involves the simultaneous dysregulation of multiple metabolic and signaling pathways through the retinal neurovascular unit. There is evidence that microvascular disease in DR is caused in part by altered energetic metabolism in the neural retina and specifically from signals originating in the photoreceptors. In this review, we discuss the main pathogenic mechanisms that link alterations in neural retina bioenergetics with vascular regression in DR. We focus specifically on the recent developments related to alterations in mitochondrial metabolism including energetic substrate selection, mitochondrial function, oxidation-reduction (redox) imbalance, and oxidative stress, and critically discuss the mechanisms of these changes and their consequences on retinal function. We also acknowledge implications for emerging therapeutic approaches and future research directions to find novel mitochondria-targeted therapeutic strategies to correct bioenergetics in diabetes. We conclude that retinal bioenergetics is affected in the early stages of diabetes with consequences beyond changes in ATP content, and that maintaining mitochondrial integrity may alleviate retinal disease.
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Abstract
PURPOSE To review the recent developments on the effect of chronic high mean arterial blood pressure (MAP) on cerebral blood flow (CBF) autoregulation and supporting the notion that CBF autoregulation impairment has connection with chronic cerebral diseases. Method: A narrative review of all the relevant papers known to the authors was conducted. Results: Our understanding of the connection between cerebral perfusion impairment and chronic high MAP and cerebral disease is rapidly evolving, from cerebral perfusion impairment being the result of cerebral diseases to being the cause of cerebral diseases. We now better understand the intertwined impact of hypertension and Alzheimer's disease (AD) on cerebrovascular sensory elements and recognize cerebrovascular elements that are more vulnerable to these diseases. Conclusion: We conclude with the suggestion that the sensory elements pathology plays important roles in intertwined mechanisms of chronic high MAP and AD that impact cerebral perfusion.
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Affiliation(s)
- Noushin Yazdani
- College of Public Health, University of South Florida , Tampa, FL, USA
| | - Mark S Kindy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Biomedical Research, James A. Haley VA Medical Center , Tampa, FL, USA
| | - Saeid Taheri
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Byrd Neuroscience Institute, University of South Florida , Tampa, FL, USA
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32
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Wang Y, Zhao CS. Sigma-1 receptor activation ameliorates LPS-induced NO production and ROS formation through the Nrf2/HO-1 signaling pathway in cultured astrocytes. Neurosci Lett 2019; 711:134387. [PMID: 31330223 DOI: 10.1016/j.neulet.2019.134387] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/26/2019] [Accepted: 07/17/2019] [Indexed: 12/16/2022]
Abstract
Accumulating evidence has shown that astrocytes play a critical role in neuroinflammation and protection against oxidative stress. In this study, we investigated the effects of sigma-1 receptor (Sig-1R) activation on lipopolysaccharide (LPS)-induced inflammatory reactions and oxidative/nitrosative stress in cultured astrocytes. We found that SA4503, a selective Sig-1R agonist, attenuated LPS-induced inflammatory reactions and oxidative/nitrosative stress by downregulating the expression of iNOS and tumor necrosis factor α (TNF-α) and upregulating glutathione (GSH) in cultured astrocytes. To investigate the mechanism by which SA4503 caused these effects, we then examined the expression of nuclear factor erythroid-derived 2-like 2 (Nrf2) and heme oxygenase-1 (HO-1) through western blotting. The results revealed that SA4503 treatment increased Nrf2 and HO-1 expression significantly. These results suggested that the antioxidative/nitrosative stress and anti-inflammatory effects of Sig-1R activation in astrocytes were partially mediated by Nrf2 and HO-1 activation.
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Affiliation(s)
- Ying Wang
- Department of Neurology, The first affiliated hospital of China Medical University, Shenyang, China; Department of Neurology, The first affiliated hospital of Dalian Medical University, Dalian, China
| | - Chuan-Sheng Zhao
- Department of Neurology, The first affiliated hospital of China Medical University, Shenyang, China.
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Oksanen M, Lehtonen S, Jaronen M, Goldsteins G, Hämäläinen RH, Koistinaho J. Astrocyte alterations in neurodegenerative pathologies and their modeling in human induced pluripotent stem cell platforms. Cell Mol Life Sci 2019; 76:2739-2760. [PMID: 31016348 PMCID: PMC6588647 DOI: 10.1007/s00018-019-03111-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 04/06/2019] [Accepted: 04/16/2019] [Indexed: 12/12/2022]
Abstract
Astrocytes are the most abundant cell type in the brain. They were long considered only as passive support for neuronal cells. However, recent data have revealed many active roles for these cells both in maintenance of the normal physiological homeostasis in the brain as well as in neurodegeneration and disease. Moreover, human astrocytes have been found to be much more complex than their rodent counterparts, and to date, astrocytes are known to actively participate in a multitude of processes such as neurotransmitter uptake and recycling, gliotransmitter release, neuroenergetics, inflammation, modulation of synaptic activity, ionic balance, maintenance of the blood-brain barrier, and many other crucial functions of the brain. This review focuses on the role of astrocytes in human neurodegenerative disease and the potential of the novel stem cell-based platforms in modeling astrocytic functions in health and in disease.
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Affiliation(s)
- Minna Oksanen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Sarka Lehtonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, PO. Box 63, 00290, Helsinki, Finland
| | - Merja Jaronen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Gundars Goldsteins
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Riikka H Hämäläinen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Jari Koistinaho
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland.
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, PO. Box 63, 00290, Helsinki, Finland.
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McConnell HL, Li Z, Woltjer RL, Mishra A. Astrocyte dysfunction and neurovascular impairment in neurological disorders: Correlation or causation? Neurochem Int 2019; 128:70-84. [PMID: 30986503 DOI: 10.1016/j.neuint.2019.04.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/14/2022]
Abstract
The neurovascular unit, consisting of neurons, astrocytes, and vascular cells, has become the focus of much discussion in the last two decades and emerging literature now suggests an association between neurovascular dysfunction and neurological disorders. In this review, we synthesize the known and suspected contributions of astrocytes to neurovascular dysfunction in disease. Throughout the brain, astrocytes are centrally positioned to dynamically mediate interactions between neurons and the cerebral vasculature, and play key roles in blood-brain barrier maintenance and neurovascular coupling. It is increasingly apparent that the changes in astrocytes in response to a variety of insults to brain tissue -collectively referred to as "reactive astrogliosis" - are not just an epiphenomenon restricted to morphological alterations, but comprise functional changes in astrocytes that contribute to the phenotype of neurological diseases with both beneficial and detrimental effects. In the context of the neurovascular unit, astrocyte dysfunction accompanies, and may contribute to, blood-brain barrier impairment and neurovascular dysregulation, highlighting the need to determine the exact nature of the relationship between astrocyte dysfunction and neurovascular impairments. Targeting astrocytes may represent a new strategy in combinatorial therapeutics for preventing the mismatch of energy supply and demand that often accompanies neurological disorders.
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Affiliation(s)
- Heather L McConnell
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
| | - Zhenzhou Li
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States; Department of Anesthesiology, General Hospital of Ningxia Medical University, Yinchuan City, China
| | - Randall L Woltjer
- Department of Neuropathology, Oregon Health & Science University, Portland, OR, United States
| | - Anusha Mishra
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States.
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Kunze R, Marti HH. Angioneurins - Key regulators of blood-brain barrier integrity during hypoxic and ischemic brain injury. Prog Neurobiol 2019; 178:101611. [PMID: 30970273 DOI: 10.1016/j.pneurobio.2019.03.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/29/2019] [Indexed: 12/14/2022]
Abstract
The loss of blood-brain barrier (BBB) integrity leading to vasogenic edema and brain swelling is a common feature of hypoxic/ischemic brain diseases such as stroke, but is also central to the etiology of other CNS disorders. In the past decades, numerous proteins, belonging to the family of angioneurins, have gained increasing attention as potential therapeutic targets for ischemic stroke, but also other CNS diseases attributed to BBB dysfunction. Angioneurins encompass mediators that affect both neuronal and vascular function. Recently, increasing evidence has been accumulated that certain angioneurins critically determine disease progression and outcome in stroke among others through multifaceted effects on the compromised BBB. Here, we will give a concise overview about the family of angioneurins. We further describe the most important cellular and molecular components that contribute to structural integrity and low permeability of the BBB under steady-state conditions. We then discuss BBB alterations in ischemic stroke, and highlight underlying cellular and molecular mechanisms. For the most prominent angioneurin family members including vascular endothelial growth factors, angiopoietins, platelet-derived growth factors and erythropoietin, we will summarize current scientific literature from experimental studies in animal models, and if available from clinical trials, on the following points: (i) spatiotemporal expression of these factors in the healthy and hypoxic/ischemic CNS, (ii) impact of loss- or gain-of-function during cerebral hypoxia/ischemia for BBB integrity and beyond, and (iii) potential underlying molecular mechanisms. Moreover, we will highlight novel therapeutic strategies based on the activation of endogenous angioneurins that might improve BBB dysfuntion during ischemic stroke.
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Affiliation(s)
- Reiner Kunze
- Institute of Physiology and Pathophysiology, Heidelberg University, Germany.
| | - Hugo H Marti
- Institute of Physiology and Pathophysiology, Heidelberg University, Germany
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Abstract
There has been extraordinary research in the blood-brain barrier. Once considered a static anatomic barrier to the traffic of molecules in and out of the central nervous system when fully developed in adults, the blood-brain barrier is now known to be not only fully functional in development but also vital in cerebrovascular angiogenesis. Blood-brain barrier breakdown has been recognized as an important factor in a variety of primary neurologic diseases; however, such disturbances have yet to be critically analyzed. This article reviews the history, neurodevelopment, ultrastructure, function, and clinicopathologic correlation and relevance to central nervous system vasculitis.
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Affiliation(s)
- David S Younger
- Department of Neurology, Division of Neuro-Epidemiology, New York University School of Medicine, New York, NY 10016, USA; School of Public Health, City University of New York, New York, NY, USA.
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37
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Shih EK, Robinson MB. Role of Astrocytic Mitochondria in Limiting Ischemic Brain Injury? Physiology (Bethesda) 2019; 33:99-112. [PMID: 29412059 DOI: 10.1152/physiol.00038.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Until recently, astrocyte processes were thought to be too small to contain mitochondria. However, it is now clear that mitochondria are found throughout fine astrocyte processes and are mobile with neuronal activity resulting in positioning near synapses. In this review, we discuss evidence that astrocytic mitochondria confer selective resiliency to astrocytes during ischemic insults and the functional significance of these mitochondria for normal brain function.
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Affiliation(s)
- Evelyn K Shih
- Children's Hospital of Philadelphia Research Institute , Philadelphia, Pennsylvania.,Children's Hospital of Philadelphia, Division of Neurology , Philadelphia, Pennsylvania.,Department of Pediatrics, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Michael B Robinson
- Children's Hospital of Philadelphia Research Institute , Philadelphia, Pennsylvania.,Department of Pediatrics, University of Pennsylvania , Philadelphia, Pennsylvania.,Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania , Philadelphia, Pennsylvania
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38
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Slupe AM, Kirsch JR. Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection. J Cereb Blood Flow Metab 2018; 38:2192-2208. [PMID: 30009645 PMCID: PMC6282215 DOI: 10.1177/0271678x18789273] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/11/2018] [Accepted: 06/25/2018] [Indexed: 12/12/2022]
Abstract
Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.
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Affiliation(s)
- Andrew M Slupe
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Jeffrey R Kirsch
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
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Shad KF, Luqman N, Simpson AM, Lal S. Peripheral Biomarker for Vascular Disorders. Biomark Insights 2018; 13:1177271918812467. [PMID: 30546256 PMCID: PMC6287300 DOI: 10.1177/1177271918812467] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 10/19/2018] [Indexed: 11/15/2022] Open
Abstract
Atherosclerosis is the underlying cause of most myocardial infarction (MI) and ischaemic stroke episodes. An early sign of atherosclerosis is hypertrophy of the arterial wall. It is known that increased intima media thickness (IMT) is a non-invasive marker of arterial wall alteration, which can easily be assessed in the carotid arteries by high-resolution B-mode ultrasound. Similarly, the other key element of MI and ischaemic strokes is the N-methyl-D-aspartate (NMDA) receptor which is an ionotropic glutamate receptor that mediates the vast majority of excitatory neurotransmission in the brain. NMDA activation requires the binding of both glutamate and a coagonist like D-serine to its glycine site. A special enzyme, serine racemase (SR), is required for the conversion of L-serine into D-serine, and alterations in SR activities lead to a variety of physiological and pathological conditions ranging from synaptic plasticity to ischemia, MI, and stroke. The amount of D-serine available for the activation of glutamatergic signalling is largely determined by SR and we have developed ways to estimate its levels in human blood samples and correlate it with the IMT. This research based short communication describes our pilot study, which clearly suggests that there is a direct relationship between the SR, D-serine, and IMT. In this article, we will discuss whether the activity of SR can determine the future consequences resulting from vascular pathologies such as MI and stroke.
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Affiliation(s)
- Kaneez Fatima Shad
- School of Life Sciences and Centre for Health Technologies, University of Technology Sydney, Broadway, NSW, Australia.,PAPRSB Institute of Health Sciences, University of Brunei Darussalam, Gadong, Brunei Darussalam
| | - Nazar Luqman
- PAPRSB Institute of Health Sciences, University of Brunei Darussalam, Gadong, Brunei Darussalam.,Cardiology Department, RIPAS Hospital, Bandar Seri Begawan, Brunei Darussalam
| | - Ann M Simpson
- School of Life Sciences and Centre for Health Technologies, University of Technology Sydney, Broadway, NSW, Australia
| | - Sara Lal
- School of Life Sciences and Centre for Health Technologies, University of Technology Sydney, Broadway, NSW, Australia.,Neuroscience Research Unit, School of Life Sciences, University of Technology Sydney, Broadway, NSW, Australia
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40
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Biophysically based method to deconvolve spatiotemporal neurovascular signals from fMRI data. J Neurosci Methods 2018; 308:6-20. [DOI: 10.1016/j.jneumeth.2018.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 12/21/2022]
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Zhang X, Guo X, Zhang N, Cai H, Sun J, Wang Q, Qi Y, Zhang L, Yang L, Shi FD, Yu C. Cerebral Blood Flow Changes in Multiple Sclerosis and Neuromyelitis Optica and Their Correlations With Clinical Disability. Front Neurol 2018; 9:305. [PMID: 29780351 PMCID: PMC5946009 DOI: 10.3389/fneur.2018.00305] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/18/2018] [Indexed: 11/13/2022] Open
Abstract
Distinguishing relapsing-remitting multiple sclerosis (RRMS) and neuromyelitis optica (NMO) is clinically important because they differ in prognosis and treatment. This study aimed to identify perfusion abnormalities in RRMS and NMO and their correlations with gray matter volume (GMV) atrophy and clinical parameters. Structural and arterial spin labeling MRI scans were performed in 39 RRMS patients, 62 NMO patients, and 73 healthy controls. The gray matter cerebral blood flow (CBF) values were voxel-wisely compared among the three groups with and without GMV correction. The regional CBF changes were correlated with the Expanded Disability Status Scale scores in the corresponding patient groups. Although multiple brain regions showed CBF differences among the three groups without GMV correction, only three of these regions remained significant after GMV correction. Specifically, both the RRMS and NMO groups showed reduced CBF in the occipital cortex and increased CBF in the right putamen compared to the control group. The RRMS group had increased CBF only in the medial prefrontal cortex compared to the other two groups. The occipital CBF was negatively correlated with clinical disability in the NMO group; however, the CBF in the right putamen was positively correlated with clinical disability in both patient groups. These findings suggest that there are perfusion alterations independent of GMV atrophy in RRMS and NMO patients. The regional CBF in the occipital cortex and putamen could be used as imaging features to objectively assess clinical disability in these patients.
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Affiliation(s)
- Xue Zhang
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin, China
| | - Xi Guo
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin, China
| | - Ningnannan Zhang
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin, China
| | - Huanhuan Cai
- Laboratory of Digital Medical Imaging, Medical Imaging Center, The First Affiliated Hospital, Anhui University of Chinese Medicine, Hefei, China
| | - Jie Sun
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin, China
| | - Qiuhui Wang
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin, China
| | - Yuan Qi
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Linjie Zhang
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Li Yang
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Fu-Dong Shi
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Chunshui Yu
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin, China
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42
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Germundson DL, Smith NA, Vendsel LP, Kelsch AV, Combs CK, Nagamoto-Combs K. Oral sensitization to whey proteins induces age- and sex-dependent behavioral abnormality and neuroinflammatory responses in a mouse model of food allergy: a potential role of mast cells. J Neuroinflammation 2018; 15:120. [PMID: 29685134 PMCID: PMC5913881 DOI: 10.1186/s12974-018-1146-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/03/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Growing evidence has strengthened the association of food allergy with neuropsychiatric symptoms such as depression, anxiety, and autism. However, underlying mechanisms by which peripheral allergic responses lead to behavioral dysfunction are yet to be determined. Allergen-activated mast cells may serve as mediators by releasing histamine and other inflammatory factors that could adversely affect brain function. We hypothesized that eliciting food allergy in experimental animals would result in behavioral changes accompanied by mast cell accumulation in the brain. Our hypothesis was tested in a mouse model of milk allergy using bovine milk whey proteins (WP) as the allergen. METHODS Male and female C57BL/6 mice at 4 weeks (young) and 10 months (old) of age underwent 5-week WP sensitization with weekly intragastric administration of 20 mg WP and 10 μg cholera toxin as an adjuvant. Age-matched sham animals were given the vehicle containing only the adjuvant. All animals were orally challenged with 50 mg WP in week 6 and their intrinsic digging behavior was assessed the next day. Animals were sacrificed 3 days after the challenge, and WP-specific serum IgE, intestinal and brain mast cells, glial activation, and epigenetic DNA modification in the brain were examined. RESULTS WP-sensitized males showed significantly less digging activity than the sham males in both age groups while no apparent difference was observed in females. Mast cells and their activities were evident in the intestines in an age- and sex-dependent manner. Brain mast cells were predominantly located in the region between the lateral midbrain and medial hippocampus, and their number increased in the WP-sensitized young, but not old, male brains. Noticeable differences in for 5-hydroxymethylcytosine immunoreactivity were observed in WP mice of both age groups in the amygdala, suggesting epigenetic regulation. Increased microglial Iba1 immunoreactivity and perivascular astrocytes hypertrophy were also observed in the WP-sensitized old male mice. CONCLUSIONS Our results demonstrated that food allergy induced behavioral abnormality, increases in the number of mast cells, epigenetic DNA modification in the brain, microgliosis, and astrocyte hypertrophy in a sex- and age-dependent manner, providing a potential mechanism by which peripheral allergic responses evoke behavioral dysfunction.
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Affiliation(s)
- Danielle L Germundson
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Nicholas A Smith
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Lane P Vendsel
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Andrea V Kelsch
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Colin K Combs
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA.
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Amtul Z, Yang J, Nikolova S, Lee TY, Bartha R, Cechetto DF. The Dynamics of Impaired Blood-Brain Barrier Restoration in a Rat Model of Co-morbid Injury. Mol Neurobiol 2018; 55:8071-8083. [PMID: 29508280 DOI: 10.1007/s12035-018-0904-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/10/2018] [Indexed: 12/31/2022]
Abstract
Defect in brain microperfusion is increasingly recognized as an antecedent event to Alzheimer's disease (AD) and ischemia. Nevertheless, studies on the role of impaired microperfusion as a pathological trigger to neuroinflammation, Aβ deposition as well as blood-brain barrier (BBB) disruption, and the etiological link between AD and ischemia are lacking. In this study, we employ in vivo sequential magnetic resonance imaging (MRI) and computed tomography (CT) imaging in a co-morbid rat model of β-amyloid toxicity (Aβ) and ischemia (ET1) with subsequent histopathology of striatal lesion core and penumbra at 1, 7, and 28 days post injury. Within 24 h, cerebral injury resulted in increased BBB permeability due to the dissolution of β-dystroglycan (β-DG) and basement membrane laminin by active matrix metalloproteinase9 (MMP9). As a result, net flow of circulating IgG down a hydrostatic gradient into the parenchyma led to vasogenic edema and impaired perfusion, thus increasing the apparent hyperintensity in true fast imaging with steady-state free precession (true FISP) imaging and acute hypoperfusion in CT. This was followed by a slow recruitment of reactive astroglia to the affected brain and depolarization of aquaporin4 (AQP4) expression resulting in cytotoxic edema-in an attempt to resolve vasogenic edema. On d28, functional BBB was restored in ET1 rats as observed by astrocytic MMP9 release, β-DG stabilization, and new vessel formation. This was confirmed by reduced hyperintensity on true FISP imaging and normalized cerebral blood flow in CT. While, Aβ toxicity alone was not detrimental enough, Aβ+ET1 rats showed delayed differential expression of MMP9, late recruitment of astroglial cells, protracted loss of AQP4 depolarization, and thus delayed BBB restoration and cerebral perfusion.
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Affiliation(s)
- Zareen Amtul
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada.
| | - Jun Yang
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Simona Nikolova
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Ting-Yim Lee
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Robert Bartha
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada.,Department of Medical Biophysics, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - David F Cechetto
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
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Gray SM, Aylor KW, Barrett EJ. Unravelling the regulation of insulin transport across the brain endothelial cell. Diabetologia 2017; 60:1512-1521. [PMID: 28601906 PMCID: PMC5534844 DOI: 10.1007/s00125-017-4285-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/23/2017] [Indexed: 11/28/2022]
Abstract
AIMS/HYPOTHESIS For circulating insulin to act on the brain it must cross the blood-brain barrier (BBB). Remarkably little is known about how circulating insulin crosses the BBB's highly restrictive brain endothelial cells (BECs). Therefore, we examined potential mechanisms regulating BEC insulin uptake, signalling and degradation during BEC transcytosis, and how transport is affected by a high-fat diet (HFD) and by astrocyte activity. METHODS 125I-TyrA14-insulin uptake and transcytosis, and the effects of insulin receptor (IR) blockade, inhibition of insulin signalling, astrocyte stimulation and an HFD were tested using purified isolated BECs (iBECs) in monoculture and co-cultured with astrocytes. RESULTS At physiological insulin concentrations, the IR, not the IGF-1 receptor, facilitated BEC insulin uptake, which required lipid raft-mediated endocytosis, but did not require insulin action on phosphoinositide-3-kinase (PI3K) or mitogen-activated protein kinase kinase (MEK). Feeding rats an HFD for 4 weeks decreased iBEC insulin uptake and increased NF-κB binding activity without affecting insulin PI3K signalling, IR expression or content, or insulin degrading enzyme expression. Using an in vitro BBB (co-culture of iBECs and astrocytes), we found insulin was not degraded during transcytosis, and that stimulating astrocytes with L-glutamate increased transcytosis, while inhibiting nitric oxide synthase decreased insulin transcytosis. CONCLUSIONS/INTERPRETATION Insulin crosses the BBB intact via an IR-specific, vesicle-mediated transport process in the BECs. HFD feeding, nitric oxide inhibition and astrocyte stimulation can regulate BEC insulin uptake and transcytosis.
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Affiliation(s)
- Sarah M Gray
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Kevin W Aylor
- Division of Endocrinology & Metabolism, Department of Medicine, University of Virginia, 450 Ray C. Hunt Drive, P.O. Box 801410, Charlottesville, VA, 22908, USA
| | - Eugene J Barrett
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.
- Division of Endocrinology & Metabolism, Department of Medicine, University of Virginia, 450 Ray C. Hunt Drive, P.O. Box 801410, Charlottesville, VA, 22908, USA.
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45
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Li H, Bui BV, Cull G, Wang F, Wang L. Glial Cell Contribution to Basal Vessel Diameter and Pressure-Initiated Vascular Responses in Rat Retina. Invest Ophthalmol Vis Sci 2017; 58:1-8. [PMID: 28055098 PMCID: PMC5225997 DOI: 10.1167/iovs.16-20804] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to test the hypothesis that retinal glial cells modify basal vessel diameter and pressure-initiated vascular regulation in rat retina. Methods In rats, L-2-aminoadipic acid (LAA, 10 nM) was intravitreally injected to inhibit glial cell activity. Twenty-four hours following injection, retinal glial intracellular calcium (Ca2+) was labeled with the fluorescent calcium indicator Fluo-4/AM (F4, 1 mM). At 110 minutes after injection, intraocular pressure (IOP) was elevated from 20 to 50 mm Hg. Prior to and during IOP elevation, Ca2+ and retinal vessel diameter were assessed using a spectral-domain optical coherence tomography/confocal scanning laser ophthalmoscope. Dynamic changes in Ca2+ and diameter from IOP elevation were quantified. The response in LAA-treated eyes was compared with vehicle treated control eyes. Results L-2-Aminoadipic acid treatment significantly reduced F4-positive cells in the retina (LAA, 16 ± 20 vs. control, 55 ± 37 cells/mm2; P = 0.02). Twenty-four hours following LAA treatment, basal venous diameter was increased from 38.9 ± 3.9 to 51.8 ± 6.4 μm (P < 0.0001, n = 20), whereas arterial diameter was unchanged (from 30.3 ± 3.5 to 30.7 ± 2.8 μm; P = 0.64). In response to IOP elevation, LAA-treated eyes showed a smaller increase in glial cell Ca2+ around both arteries and veins in comparison with control (P < 0.001 for both). There was also significantly greater IOP-induced vasoconstriction in both vessel types (P = 0.05 and P = 0.02, respectively; n = 6 each). Conclusions The results suggest that glial cells can modulate basal retinal venous diameter and contribute to pressure-initiated vascular responses.
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Affiliation(s)
- Hui Li
- Department of Ophthalmology, The Tenth People's Hospital, Shanghai, Tongji University School of Medicine, Shanghai, China 2Devers Eye Institute, Legacy Research Institute, Portland, Oregon, USA
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Grant Cull
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, USA
| | - Fang Wang
- Department of Ophthalmology, The Tenth People's Hospital, Shanghai, Tongji University School of Medicine, Shanghai, China
| | - Lin Wang
- Department of Ophthalmology, The Tenth People's Hospital, Shanghai, Tongji University School of Medicine, Shanghai, China 2Devers Eye Institute, Legacy Research Institute, Portland, Oregon, USA
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46
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Inhibition of Gap Junction Elevates Glutamate Uptake in Cultured Astrocytes. Neurochem Res 2017; 43:59-65. [PMID: 28589517 DOI: 10.1007/s11064-017-2316-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/26/2017] [Accepted: 05/27/2017] [Indexed: 10/19/2022]
Abstract
Glutamate uptake is a main function of astrocytes to keep extracellular glutamate levels low and protect neurons against glutamate-induced excitotoxicity. On the other hand, astrocyte networks formed by gap junctions, which are consisted with connexins and connecting neighboring cells, are reported to play a critical role in maintaining the homeostasis in the brain. In the present study, we examined the effects of gap junction inhibitors on the glutamate uptake activity in cultured rat cortical astrocytes. At first, we confirmed the effects of gap junction inhibitors, 1-octanol and carbenoxolone, on cell-cell communication by the scrape-loading assay using a fluorescent dye Lucifer yellow. Both of 1-octanol and carbenoxolone treatments for 20 min in cultured astrocytes significantly suppressed the cell-cell communication assessed as the distance of dye-spreading. 1-octanol and carbenoxolone increased the glutamate uptake by astrocytes and glutamate aspartate transporter (GLAST) expression on the cell membrane. These results suggest that gap junction inhibitors increase the glutamate uptake activity through the increase of GLAST proteins located on the cell membrane. The regulation of gap junction in astrocytes might protect neurons against glutamate-induced excitotoxicity.
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Theodorakis PE, Müller EA, Craster RV, Matar OK. Physical insights into the blood-brain barrier translocation mechanisms. Phys Biol 2017; 14:041001. [PMID: 28586313 DOI: 10.1088/1478-3975/aa708a] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The number of individuals suffering from diseases of the central nervous system (CNS) is growing with an aging population. While candidate drugs for many of these diseases are available, most of these pharmaceutical agents cannot reach the brain rendering most of the drug therapies that target the CNS inefficient. The reason is the blood-brain barrier (BBB), a complex and dynamic interface that controls the influx and efflux of substances through a number of different translocation mechanisms. Here, we present these mechanisms providing, also, the necessary background related to the morphology and various characteristics of the BBB. Moreover, we discuss various numerical and simulation approaches used to study the BBB, and possible future directions based on multi-scale methods. We anticipate that this review will motivate multi-disciplinary research on the BBB aiming at the design of effective drug therapies.
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Sonnay S, Gruetter R, Duarte JMN. How Energy Metabolism Supports Cerebral Function: Insights from 13C Magnetic Resonance Studies In vivo. Front Neurosci 2017; 11:288. [PMID: 28603480 PMCID: PMC5445183 DOI: 10.3389/fnins.2017.00288] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/04/2017] [Indexed: 12/25/2022] Open
Abstract
Cerebral function is associated with exceptionally high metabolic activity, and requires continuous supply of oxygen and nutrients from the blood stream. Since the mid-twentieth century the idea that brain energy metabolism is coupled to neuronal activity has emerged, and a number of studies supported this hypothesis. Moreover, brain energy metabolism was demonstrated to be compartmentalized in neurons and astrocytes, and astrocytic glycolysis was proposed to serve the energetic demands of glutamatergic activity. Shedding light on the role of astrocytes in brain metabolism, the earlier picture of astrocytes being restricted to a scaffold-associated function in the brain is now out of date. With the development and optimization of non-invasive techniques, such as nuclear magnetic resonance spectroscopy (MRS), several groups have worked on assessing cerebral metabolism in vivo. In this context, 1H MRS has allowed the measurements of energy metabolism-related compounds, whose concentrations can vary under different brain activation states. 1H-[13C] MRS, i.e., indirect detection of signals from 13C-coupled 1H, together with infusion of 13C-enriched glucose has provided insights into the coupling between neurotransmission and glucose oxidation. Although these techniques tackle the coupling between neuronal activity and metabolism, they lack chemical specificity and fail in providing information on neuronal and glial metabolic pathways underlying those processes. Currently, the improvement of detection modalities (i.e., direct detection of 13C isotopomers), the progress in building adequate mathematical models along with the increase in magnetic field strength now available render possible detailed compartmentalized metabolic flux characterization. In particular, direct 13C MRS offers more detailed dataset acquisitions and provides information on metabolic interactions between neurons and astrocytes, and their role in supporting neurotransmission. Here, we review state-of-the-art MR methods to study brain function and metabolism in vivo, and their contribution to the current understanding of how astrocytic energy metabolism supports glutamatergic activity and cerebral function. In this context, recent data suggests that astrocytic metabolism has been underestimated. Namely, the rate of oxidative metabolism in astrocytes is about half of that in neurons, and it can increase as much as the rate of neuronal metabolism in response to sensory stimulation.
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Affiliation(s)
- Sarah Sonnay
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de LausanneLausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de LausanneLausanne, Switzerland.,Department of Radiology, University of LausanneLausanne, Switzerland.,Department of Radiology, University of GenevaGeneva, Switzerland
| | - João M N Duarte
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de LausanneLausanne, Switzerland
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Novel Wavelet Real Time Analysis of Neurovascular Coupling in Neonatal Encephalopathy. Sci Rep 2017; 7:45958. [PMID: 28393884 PMCID: PMC5385531 DOI: 10.1038/srep45958] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 03/07/2017] [Indexed: 11/08/2022] Open
Abstract
Birth asphyxia constitutes a major global public health burden for millions of infants, despite hypothermia therapy. There is a critical need for real time surrogate markers of therapeutic success, to aid in patient selection and/or modification of interventions in neonatal encephalopathy (NE). This is a proof of concept study aiming to quantify neurovascular coupling (NVC) using wavelet analysis of the dynamic coherence between amplitude-integrated electroencephalography (aEEG) and near-infrared spectroscopy in NE. NVC coupling is assessed by a wavelet metric estimation of percent time of coherence between NIRS SctO2 and aEEG for 78 hours after birth. An abnormal outcome was predefined by a Bayley III score <85 by 18–24 m. We observed high coherence, intact NVC, between the oscillations of SctO2 and aEEG in the frequency range of 0.00025–0.001 Hz in the non-encephalopathic newborns. NVC coherence was significantly decreased in encephalopathic newborns who were cooled vs. non-encephalopathic controls (median IQR 3[2–9] vs.36 [33–39]; p < 0.01), and was significantly lower in those with abnormal 24 months outcomes relative to those with normal outcomes (median IQR 2[1–3] vs 28[19–26], p = 0.04). Wavelet coherence analysis of neurovascular coupling in NE may identify infants at risk for abnormal outcomes.
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Eltony SA, Abdelhameed SY. Effect of chronic administration of sildenafil citrate (Viagra) on the histology of the retina and optic nerve of adult male rat. Tissue Cell 2017; 49:323-335. [PMID: 28237322 DOI: 10.1016/j.tice.2017.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Abnormal vision has been reported by 3% of patients treated with sildenafil citrate (Viagra). Although many men use Viagra for an extended period for treatment of erectile dysfunction, the implications of the long term-daily use of it on the retina and optic nerve are unclear. AIM OF THE WORK To investigate the effect of chronic daily use of sildenafil citrate in a dose equivalent to men preferred therapeutic dose on the histology of the retina and optic nerve of adult male rat. MATERIAL & METHODS Eighteen adult male Wistar rats were equally divided into three groups. Group I: control. Group II: treated with sildenafil citrate orally (10mg/kg/day) for 8 weeks. Group III (withdrawal): treated as group II and then left for 4 weeks without treatment. Specimens from the retina and optic nerve were processed for light and electron microscopy. RESULTS In sildenafil citrate treated group, the retina and optic nerve revealed vacuolations and congested blood capillaries with apoptotic endothelial and pericytic cells, and thickened basal lamina. Caspase-3 (apoptotic marker) and CD31 (endothelial marker) expression increased. Glial cells revealed morphological changes: Müller cells lost their processes, activated microglia, astrocytic clasmatodendrosis, degenerated oligodendrocytes surrounded by disintegrated myelin sheathes of the optic nerve fibers. The retina and optic nerve of the withdrawal group revealed less vacuolations and congestion, and partial recovery of the glial cells. CONCLUSION Chronic treatment with sildenafil citrate (Viagra) caused toxic effect on the structure of the retina and optic nerve of the rat. Partial recovery was observed after drug withdrawal.
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Affiliation(s)
- Sohair A Eltony
- Histology and Cell Biology Department, Faculty of Medicine, Assiut University, Egypt.
| | - Sally Y Abdelhameed
- Forensic Medicine and Clinical Toxicology Department, Faculty of Medicine, Assiut University, Egypt
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