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Johnson AC. Hippocampal Vascular Supply and Its Role in Vascular Cognitive Impairment. Stroke 2023; 54:673-685. [PMID: 36848422 PMCID: PMC9991081 DOI: 10.1161/strokeaha.122.038263] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 12/22/2022] [Indexed: 03/01/2023]
Abstract
The incidence of age-related dementia is increasing as the world population ages and due to lack of effective treatments for dementia. Vascular contributions to cognitive impairment and dementia are increasing as the prevalence of pathologies associated with cerebrovascular disease rise, including chronic hypertension, diabetes, and ischemic stroke. The hippocampus is a bilateral deep brain structure that is central to learning, memory, and cognitive function and highly susceptible to hypoxic/ischemic injury. Compared with cortical brain regions such as the somatosensory cortex, less is known about the function of the hippocampal vasculature that is critical in maintaining neurocognitive health. This review focuses on the hippocampal vascular supply, presenting what is known about hippocampal hemodynamics and blood-brain barrier function during health and disease, and discusses evidence that supports its contribution to vascular cognitive impairment and dementia. Understanding vascular-mediated hippocampal injury that contributes to memory dysfunction during healthy aging and cerebrovascular disease is essential to develop effective treatments to slow cognitive decline. The hippocampus and its vasculature may represent one such therapeutic target to mitigate the dementia epidemic.
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Affiliation(s)
- Abbie C Johnson
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington
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2
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Das N, Ren J, Spence J, Chapman SB. Phosphate Brain Energy Metabolism and Cognition in Alzheimer's Disease: A Spectroscopy Study Using Whole-Brain Volume-Coil 31Phosphorus Magnetic Resonance Spectroscopy at 7Tesla. Front Neurosci 2021; 15:641739. [PMID: 33889067 PMCID: PMC8055842 DOI: 10.3389/fnins.2021.641739] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Mitochondrial dysfunction is a neurometabolic hallmark signaling abnormal brain energy metabolism (BEM) targeted as a potential early marker of Alzheimer’s disease (AD). Advanced imaging technologies, such as 31phosphorus magnetic resonance spectroscopy (31P MRS) at ultra-high-field (UHF) magnetic strength 7T, provide sensitive phosphate-BEM (p-BEM) data with precision. The study’s first goal was to develop a methodology to measure phosphate energy and membrane metabolites simultaneously across the whole-brain using volume-coil 31P MRS at 7T in three groups-cognitively normal (CN), amnestic mild cognitive impairment (aMCI), and AD. The second aim investigated whether p-BEM markers in the four brain regions-frontal, temporal, parietal, and occipital were significantly different across the three groups. The final goal examined correspondence between the p-BEM markers and cognition in the three groups. Methods Forty-one participants (CN = 15, aMCI = 15, AD = 11) were enrolled and completed cognitive assessment and scan. The cognitive domains included executive function (EF), memory, attention, visuospatial skills, and language. The p-BEM markers were measured using energy reserve index (PCr/t-ATP), energy consumption index (intracellular_Pi/t-ATP), metabolic state indicator (intracellular_Pi/PCr), and regulatory co-factors [magnesium (Mg2+) and intracellular pH]. Results Thirteen metabolites were measured simultaneously from the whole brain for all three group with high spectral resolution at UHF. In the aMCI group, a lower p-BEM was observed compared to CN group based on two markers, i.e., energy reserve (p = 0.009) and energy consumption (p = 0.05) indices; whereas in AD a significant increase was found in metabolic stress indicator (p = 0.007) and lower Mg2+ (p = 0.004) in the temporal lobes compared to aMCI using ANOVA between group analytical approach. Finally, using a linear mixed model, a significant positive correlation was found between Mg2+ and cognitive performance of memory (p = 0.013), EF (p = 0.023), and attention (p = 0.0003) in CN but not in aMCI or AD. Conclusion To our knowledge, this is the first study to show that it is possible to measure p-BEM in vivo with precision at UHF across the three groups. Moreover, the findings suggest that p-BEM may be compromised in aMCI even before an AD diagnosis, which in future studies should explore to examine whether this energy crisis contributes to some of the earliest neuropathophysiologic changes in AD.
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Affiliation(s)
- Namrata Das
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
| | - Jimin Ren
- Department of Radiology, Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jeffrey Spence
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
| | - Sandra Bond Chapman
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
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3
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Szegedi S, Dal‐Bianco P, Stögmann E, Traub‐Weidinger T, Rainer M, Masching A, Schmidl D, Werkmeister RM, Chua J, Schmetterer L, Garhöfer G. Anatomical and functional changes in the retina in patients with Alzheimer's disease and mild cognitive impairment. Acta Ophthalmol 2020; 98:e914-e921. [PMID: 32212415 PMCID: PMC7687124 DOI: 10.1111/aos.14419] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/04/2020] [Indexed: 01/14/2023]
Abstract
PURPOSE There is evidence that mild cognitive impairment (MCI) or Alzheimer's disease (AD) is accompanied by alterations in the retina. The current study was performed to investigate structural and functional changes in patients with systemic neurodegenerative disease. METHODS A total of 47 patients with either MCI or AD and 43 healthy age- and sex-matched control subjects were included. Inclusion criteria for MCI were abnormal memory function and a mini-mental state examination (MMSE) score >26 points, for patients with AD a diagnosis of probable AD of mild to moderate degree and an MMSE score in the range of 20-26. Retinal blood flow was measured using a Doppler optical coherence tomography (OCT) system. Retinal vessel diameter, oxygen saturation and flicker-induced vasodilatation were measured using a Vessel Analyzer. Retinal nerve fibre layer thickness (RNFLT) was assessed using an OCT system. RESULTS Global RNFLT was lower in patients compared to healthy controls (93.7 ± 12.8 µm versus 99.1 ± 9.0 µm, p = 0.02). The same was found in regards to retinal arterial blood flow, which was 9.3 ± 2.4 and 12.3 ± 3.2 μl/min in the patient and control groups, respectively (p < 0.001). Mean retinal arterial diameter was reduced in patients (76.0 ± 8.9 µm versus 80.6 ± 8.0 µm, p = 0.03). Arteriovenous difference in oxygen saturation was lower in patients (20.4 ± 5.1% versus 23.5 ± 4.0%, p < 0.01). No difference in the flicker response was observed. CONCLUSION In patients with MCI and AD, arteriovenous difference in oxygen saturation, retinal blood flow and arterial vessel diameter was reduced. No difference was found in flicker response between groups. This indicates alterations in retinal oxygen metabolism in patients with neurodegenerative disease.
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Affiliation(s)
- Stephan Szegedi
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
| | - Peter Dal‐Bianco
- Department of NeurologyMedical University of ViennaViennaAustria
| | | | - Tatjana Traub‐Weidinger
- Division of Nuclear MedicineDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria
| | - Michael Rainer
- Department of PsychiatrySocial and Medical Centre East – Danube HospitalViennaAustria
- Karl Landsteiner Institute for Memory and Alzheimer ResearchViennaAustria
| | - Andreas Masching
- Department of PsychiatrySocial and Medical Centre East – Danube HospitalViennaAustria
| | - Doreen Schmidl
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
| | - René M. Werkmeister
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Jacqueline Chua
- Singapore Eye Research InstituteSingapore National Eye CentreSingapore CitySingapore
- Ophthalmology and Visual Sciences Academic Clinical ProgramDuke‐NUS Medical SchoolSingapore CitySingapore
| | - Leopold Schmetterer
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
- Singapore Eye Research InstituteSingapore National Eye CentreSingapore CitySingapore
- Ophthalmology and Visual Sciences Academic Clinical ProgramDuke‐NUS Medical SchoolSingapore CitySingapore
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingapore CitySingapore
- Institute of Molecular and Clinical OphthalmologyBaselSwitzerland
| | - Gerhard Garhöfer
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
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4
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Hosford PS, Christie IN, Niranjan A, Aziz Q, Anderson N, Ang R, Lythgoe MF, Wells JA, Tinker A, Gourine AV. A critical role for the ATP-sensitive potassium channel subunit K IR6.1 in the control of cerebral blood flow. J Cereb Blood Flow Metab 2019; 39:2089-2095. [PMID: 29862863 PMCID: PMC6775590 DOI: 10.1177/0271678x18780602] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 04/20/2018] [Accepted: 05/01/2018] [Indexed: 12/19/2022]
Abstract
KIR6.1 (KCNJ8) is a subunit of ATP sensitive potassium channel (KATP) that plays an important role in the control of peripheral vascular tone and is highly expressed in brain contractile cells (vascular smooth muscle cells and pericytes). This study determined the effect of global deletion of the KIR6.1 subunit on cerebral blood flow, neurovascular coupling and cerebral oxygenation in mice. In KIR6.1 deficient mice resting cerebral blood flow and brain parenchymal partial pressure of oxygen (PO2) were found to be markedly lower compared to that in their wildtype littermates. However, cortical blood oxygen level dependent responses triggered by visual stimuli were not affected in conditions of KIR6.1 deficiency. These data suggest that KATP channels containing KIR6.1 subunit are critically important for the maintenance of normal cerebral perfusion and parenchymal PO2 but play no significant role in the mechanisms underlying functional changes in brain blood flow.
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Affiliation(s)
- Patrick S Hosford
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, UK
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Isabel N Christie
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, UK
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Arun Niranjan
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Qadeer Aziz
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, UK
| | - Naomi Anderson
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, UK
| | - Richard Ang
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Mark F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Jack A Wells
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Andrew Tinker
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, UK
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5
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Lourenço CF, Ledo A, Caetano M, Barbosa RM, Laranjinha J. Age-Dependent Impairment of Neurovascular and Neurometabolic Coupling in the Hippocampus. Front Physiol 2018; 9:913. [PMID: 30065657 PMCID: PMC6056650 DOI: 10.3389/fphys.2018.00913] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/21/2018] [Indexed: 11/24/2022] Open
Abstract
Neurovascular and neurometabolic coupling are critical and complex processes underlying brain function. Perturbations in the regulation of these processes are, likely, early dysfunctional alterations in pathological brain aging and age-related neurodegeneration. Evidences support the role of nitric oxide (•NO) as a key messenger both in neurovascular coupling, by signaling from neurons to blood vessels, and in neurometabolic coupling, by modulating O2 utilization by mitochondria. In the present study, we investigated the functionality of neurovascular and neurometabolic coupling in connection to •NO signaling and in association to cognitive performance during aging. For this, we performed in vivo simultaneous measurements of •NO, O2 and cerebral blood flow (CBF) in the hippocampus of F344 rats along chronological age in response to glutamatergic activation and in correlation with cognitive performance. Firstly, it is evidenced the temporal sequence of events upon glutamate stimulation of hippocampal dentate gyrus, encompassing the local and transitory increase of •NO followed by transitory local changes of CBF and pO2. Specifically, the transient increase of •NO is followed by an increase of CBF and biphasic changes of the local pO2. We observed that, although the glutamate-induced •NO dynamics were not significantly affected by aging, the correspondent hemodynamic was progressively diminished accompanying a decline in learning and memory. Noteworthy, in spite of a compromised blood supply, in aged rats we observed an increased ΔpO2 associated to the hemodynamic response, suggestive of a decrease in the global metabolic rate of O2. Furthermore, the impairment in the neurovascular coupling observed along aging in F344 rats was mimicked in young rats by promoting an unbalance in redox status toward oxidation via intracellular generation of superoxide radical. This observation strengthens the idea that oxidative stress may have a critical role in the neurovascular uncoupling underlying brain aging and dysfunction. Overall, data supports an impairment of neurovascular response in connection with cognition decline due to oxidative environment-dependent compromised •NO signaling from neurons to vessels during aging.
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Affiliation(s)
- Cátia F Lourenço
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ana Ledo
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Miguel Caetano
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Rui M Barbosa
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - João Laranjinha
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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6
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Guerra G, Lucariello A, Perna A, Botta L, De Luca A, Moccia F. The Role of Endothelial Ca 2+ Signaling in Neurovascular Coupling: A View from the Lumen. Int J Mol Sci 2018; 19:E938. [PMID: 29561829 PMCID: PMC5979341 DOI: 10.3390/ijms19040938] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Neurovascular coupling (NVC) is the mechanism whereby an increase in neuronal activity (NA) leads to local elevation in cerebral blood flow (CBF) to match the metabolic requirements of firing neurons. Following synaptic activity, an increase in neuronal and/or astrocyte Ca2+ concentration leads to the synthesis of multiple vasoactive messengers. Curiously, the role of endothelial Ca2+ signaling in NVC has been rather neglected, although endothelial cells are known to control the vascular tone in a Ca2+-dependent manner throughout peripheral vasculature. METHODS We analyzed the literature in search of the most recent updates on the potential role of endothelial Ca2+ signaling in NVC. RESULTS We found that several neurotransmitters (i.e., glutamate and acetylcholine) and neuromodulators (e.g., ATP) can induce dilation of cerebral vessels by inducing an increase in endothelial Ca2+ concentration. This, in turn, results in nitric oxide or prostaglandin E2 release or activate intermediate and small-conductance Ca2+-activated K⁺ channels, which are responsible for endothelial-dependent hyperpolarization (EDH). In addition, brain endothelial cells express multiple transient receptor potential (TRP) channels (i.e., TRPC3, TRPV3, TRPV4, TRPA1), which induce vasodilation by activating EDH. CONCLUSIONS It is possible to conclude that endothelial Ca2+ signaling is an emerging pathway in the control of NVC.
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Affiliation(s)
- Germano Guerra
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, via F. De Santis, 86100 Campobasso, Italy.
| | - Angela Lucariello
- Department of Mental Health and Preventive Medicine, Section of Human Anatomy, University of Campania "L. Vanvitelli", 81100 Naples, Italy.
| | - Angelica Perna
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, via F. De Santis, 86100 Campobasso, Italy.
| | - Laura Botta
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Forlanini 6, 27100 Pavia, Italy.
| | - Antonio De Luca
- Department of Mental Health and Preventive Medicine, Section of Human Anatomy, University of Campania "L. Vanvitelli", 81100 Naples, Italy.
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Forlanini 6, 27100 Pavia, Italy.
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7
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Gruszecki M, Lancaster G, Stefanovska A, Neary JP, Dech RT, Guminski W, Frydrychowski AF, Kot J, Winklewski PJ. Human subarachnoid space width oscillations in the resting state. Sci Rep 2018; 8:3057. [PMID: 29449606 PMCID: PMC5814422 DOI: 10.1038/s41598-018-21038-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/29/2018] [Indexed: 11/17/2022] Open
Abstract
Abnormal cerebrospinal fluid (CSF) pulsatility has been implicated in patients suffering from various diseases, including multiple sclerosis and hypertension. CSF pulsatility results in subarachnoid space (SAS) width changes, which can be measured with near-infrared transillumination backscattering sounding (NIR-T/BSS). The aim of this study was to combine NIR-T/BSS and wavelet analysis methods to characterise the dynamics of the SAS width within a wide range of frequencies from 0.005 to 2 Hz, with low frequencies studied in detail for the first time. From recordings in the resting state, we also demonstrate the relationships between SAS width in both hemispheres of the brain, and investigate how the SAS width dynamics is related to the blood pressure (BP). These investigations also revealed influences of age and SAS correlation on the dynamics of SAS width and its similarity with the BP. Combination of NIR-T/BSS and time-frequency analysis may open up new frontiers in the understanding and diagnosis of various neurodegenerative and ageing related diseases to improve diagnostic procedures and patient prognosis.
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Affiliation(s)
- Marcin Gruszecki
- Department of Radiology Informatics and Statistics, Medical University of Gdansk, Gdansk, Poland.
| | | | | | - J Patrick Neary
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | - Ryan T Dech
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | - Wojciech Guminski
- Department of Computer Communications, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | | | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Gdynia, Poland
| | - Pawel J Winklewski
- Department of Human Physiology, Medical University of Gdansk, Gdansk, Poland.,Department of Clinical Anatomy and Physiology, Pomeranian University of Slupsk, Slupsk, Poland
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8
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Grosu C, Oprescu AC, Niţă O, Bild W. Insulin and the Brain. ROMANIAN JOURNAL OF DIABETES NUTRITION AND METABOLIC DISEASES 2017. [DOI: 10.1515/rjdnmd-2017-0044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract
The brain represents an important site for the action of insulin. Besides the traditionally known importance in glucoregulation, insulin has significant neurotrophic properties and influences the brain activity: insulin influences eating behavior, regulates the storage of energy and several aspects concerning memory and knowledge. Insulin resistance and hyperinsulinism could be associated with brain aging, vascular and metabolic pathologies. Elucidating the pathways and metabolism of brain insulin could have a major impact on future targeted therapies.
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Affiliation(s)
- Cristina Grosu
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Neurology , Clinical Rehabilitation Hospital Iasi , Romania
| | - Andrei Cătălin Oprescu
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Diabetes, Nutrition and Metabolic Diseases , “Sf Spiridon” Clinical Emergency Hospital Iasi , Romania
| | - Otilia Niţă
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Diabetes, Nutrition and Metabolic Diseases , “Sf Spiridon” Clinical Emergency Hospital Iasi , Romania
| | - Walther Bild
- “Grigore T. Popa” University of Medicine and Pharmacy Iasi , Romania
- Department of Normal and Pathologic Physiology
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9
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Duncombe J, Lennen RJ, Jansen MA, Marshall I, Wardlaw JM, Horsburgh K. Ageing causes prominent neurovascular dysfunction associated with loss of astrocytic contacts and gliosis. Neuropathol Appl Neurobiol 2017; 43:477-491. [PMID: 28039950 DOI: 10.1111/nan.12375] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 12/23/2016] [Accepted: 12/31/2016] [Indexed: 01/20/2023]
Abstract
AIMS Normal neurovascular coupling, mediated by the fine interplay and communication of cells within the neurovascular unit, is critical for maintaining normal brain activity and cognitive function. This study investigated whether, with advancing age there is disruption of neurovascular coupling and specific cellular components of the neurovascular unit, and whether the effects of increasing amyloid (a key feature of Alzheimer's disease) would exacerbate these changes. METHODS Wild-type mice, in which amyloid deposition is absent, were compared to transgenic amyloid precursor protein (APP) littermates (TgSwDI) which develop age-dependent increases in amyloid. Baseline cerebral blood flow and responses to whisker stimulation were measured. Components of the neurovascular unit (astrocytes, end-feet, pericytes, microglia) were measured by immunohistochemistry. RESULTS Neurovascular coupling was progressively impaired with increasing age (starting at 12 months) but was not further altered in TgSwDI mice. Aged mice showed reduced vascular pericyte coverage relative to young but this was not related to neurovascular function. Aged mice displayed significant reductions in astrocytic end-feet expression of aquaporin-4 on blood vessels compared to young mice, and a prominent increase in microglial proliferation which correlated with neurovascular function. CONCLUSIONS Strategies aimed to restore the loss of astrocytic end feet contact and reduce gliosis may improve neurovascular coupling.
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Affiliation(s)
- J Duncombe
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - R J Lennen
- BHF/Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - M A Jansen
- BHF/Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - I Marshall
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - J M Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - K Horsburgh
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
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10
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Geraldes R, Esiri MM, DeLuca GC, Palace J. Age-related small vessel disease: a potential contributor to neurodegeneration in multiple sclerosis. Brain Pathol 2017; 27:707-722. [PMID: 27864848 DOI: 10.1111/bpa.12460] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 11/17/2016] [Indexed: 12/18/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system wherein, after an initial phase of transient neurological defects, slow neurological deterioration due to progressive neuronal loss ensues. Age is a major determinant of MS progression onset and disability. Over the past years, several mechanisms have been proposed to explain the key drivers of neurodegeneration and disability accumulation in MS. However, the effect of commonly encountered age-related cerebral vessel disease, namely small vessel disease (SVD), has been largely neglected and constitutes the aim of this review. SVD shares some features with MS, that is, white matter demyelination and brain atrophy, and has been shown to contribute to the neuronal damage seen in vascular cognitive impairment. Several lines of evidence suggest that an interaction between MS and SVD may influence MS-related neurodegeneration. SVD may contribute to hypoperfusion, reduced vascular reactivity and tissue hypoxia, features seen in MS. Venule and endothelium abnormalities have been documented in MS but the role of arterioles and of other neurovascular unit structures, such as the pericyte, has not been explored. Vascular risk factors (VRF) have recently been associated with faster progression in MS, though the mechanisms are unclear since very few studies have addressed the impact of VRF and SVD on MS imaging and pathology outcomes. Therapeutic agents targeting the microvasculature and the neurovascular unit may impact both SVD and MS and may benefit patients with dual pathology.
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Affiliation(s)
- Ruth Geraldes
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Margaret M Esiri
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Gabriele C DeLuca
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
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11
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Baldassarro VA, Marchesini A, Giardino L, Calzà L. Vulnerability of primary neurons derived from Tg2576 Alzheimer mice to oxygen and glucose deprivation: role of intraneuronal amyloid-β accumulation and astrocytes. Dis Model Mech 2017; 10:671-678. [PMID: 28237964 PMCID: PMC5451168 DOI: 10.1242/dmm.028001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/17/2017] [Indexed: 12/12/2022] Open
Abstract
Microvascular dysfunction is considered an integral part of Alzheimer disease (AD) pathogenesis, but the possible relationship between amyloid pathology, microvascular dysfunction and cell death is still unclear. In order to investigate the influence of intraneuronal amyloid-β (Aβ) accumulation on vulnerability to hypoxia, we isolated primary cortical neurons from Tg2576 (carrying the amyloid precursor protein APPSwe mutation) and wild-type fetal mice. We first demonstrated that neurons isolated from Tg2576 newborn mice show an increase in VEGFa mRNA expression and a decrease in the expression of the two VEGF receptors, Flt1 and Kdr, compared with wild-type cells. Moreover, APPSwe primary neurons displayed higher spontaneous and glutamate-induced cell death. We then deprived the cultures of oxygen and glucose (OGD) as an in vitro model of hypoxia. After OGD, APPSwe neurons display higher levels of cell death in terms of percentage of pyknotic/fragmented nuclei and mitochondrial depolarization, accompanied by an increase in the intraneuronal Aβ content. To explore the influence of intraneuronal Aβ peptide accumulation, we used the γ-secretase inhibitor LY450139, which showed that the reduction of the intracellular amyloid fully protects APPSwe neurons from OGD-induced degeneration. Conditioned medium from OGD-exposed APPSwe or wild-type astrocytes protected APPswe neurons but not wild-type neurons, during OGD. In conclusion, the presence of the mutated human APP gene, leading to the intracellular accumulation of APP and Aβ fragments, worsens OGD toxicity. Protection of APPSwe neurons can be obtained either using a γ-secretase inhibitor or astrocyte conditioned medium. Summary:In vitro systems derived from AD mice can be used to investigate the vulnerability of AD neurons to different neurotoxic challenges, including oxygen glucose deprivation.
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Affiliation(s)
- Vito Antonio Baldassarro
- Interdepartmental Centre for Industrial Research in Health Science and Technologies (ICIR - HST), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy.,Department of Pharmacy and Biotechnology (FaBit), University of Bologna, 40127 Bologna, Italy
| | | | - Luciana Giardino
- Interdepartmental Centre for Industrial Research in Health Science and Technologies (ICIR - HST), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy.,Department of Medical Veterinary Sciences (DIMEVET), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy.,Fondazione IRET, 40064 Ozzano Emilia, Bologna, Italy
| | - Laura Calzà
- Interdepartmental Centre for Industrial Research in Health Science and Technologies (ICIR - HST), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy .,Department of Pharmacy and Biotechnology (FaBit), University of Bologna, 40127 Bologna, Italy.,Fondazione IRET, 40064 Ozzano Emilia, Bologna, Italy
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Corriveau RA, Bosetti F, Emr M, Gladman JT, Koenig JI, Moy CS, Pahigiannis K, Waddy SP, Koroshetz W. The Science of Vascular Contributions to Cognitive Impairment and Dementia (VCID): A Framework for Advancing Research Priorities in the Cerebrovascular Biology of Cognitive Decline. Cell Mol Neurobiol 2016; 36:281-8. [PMID: 27095366 DOI: 10.1007/s10571-016-0334-7] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/22/2016] [Indexed: 01/17/2023]
Abstract
The World Health Organization reports that 47.5 million people are affected by dementia worldwide. With aging populations and 7.7 million new cases each year, the burden of illness due to dementia approaches crisis proportions. Despite significant advances in our understanding of the biology of Alzheimer's disease (AD), the leading dementia diagnosis, the actual causes of dementia in affected individuals are unknown except for rare fully penetrant genetic forms. Evidence from epidemiology and pathology studies indicates that damage to the vascular system is associated with an increased risk of many types of dementia. Both Alzheimer's pathology and cerebrovascular disease increase with age. How AD affects small blood vessel function and how vascular dysfunction contributes to the molecular pathology of Alzheimer's are areas of intense research. The science of vascular contributions to cognitive impairment and dementia (VCID) integrates diverse aspects of biology and incorporates the roles of multiple cell types that support the function of neural tissue. Because of the proven ability to prevent and treat cardiovascular disease and hypertension with population benefits for heart and stroke outcomes, it is proposed that understanding and targeting the biological mechanisms of VCID can have a similarly positive impact on public health.
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Affiliation(s)
- Roderick A Corriveau
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA.
| | - Francesca Bosetti
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - Marian Emr
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - Jordan T Gladman
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - James I Koenig
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - Claudia S Moy
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - Katherine Pahigiannis
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - Salina P Waddy
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
| | - Walter Koroshetz
- National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), 6001 Executive Blvd, Bethesda, MD, 20892-9525, USA
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Huang H, Yang J, Luciano M, Shriver LP. Longitudinal Metabolite Profiling of Cerebrospinal Fluid in Normal Pressure Hydrocephalus Links Brain Metabolism with Exercise-Induced VEGF Production and Clinical Outcome. Neurochem Res 2016; 41:1713-22. [PMID: 27084769 DOI: 10.1007/s11064-016-1887-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 12/15/2022]
Abstract
Idiopathic normal pressure hydrocephalus is a neurological disease caused by abnormal cerebrospinal fluid flow and presents with symptoms such as dementia. Current therapy involves the removal of excess cerebrospinal fluid by shunting. Not all patients respond to this therapy and biomarkers are needed that could facilitate the characterization of patients likely to benefit from this treatment. Here, we measure brain metabolism in normal pressure hydrocephalus patients by performing a novel longitudinal metabolomic profiling study of cerebrospinal fluid. We find that the levels of brain metabolites correlate with clinical parameters, the amount of vascular endothelial growth factor in the cerebrospinal fluid, and environmental stimuli such as exercise. Metabolomic analysis of normal pressure hydrocephalus patients provides insight into changes in brain metabolism that accompany cerebrospinal fluid disorders and may facilitate the development of new biomarkers for this condition.
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Affiliation(s)
- He Huang
- Departments of Chemistry and Biology, University of Akron, Akron, OH, 44325, USA
| | - Jun Yang
- Department of Neurological Surgery, Section of Pediatric and Congenital Neurological Surgery, CSF Physiology Laboratory, Neurological Institute Cleveland Clinic, Cleveland, OH, 44106, USA
| | - Mark Luciano
- Department of Neurological Surgery, Section of Pediatric and Congenital Neurological Surgery, CSF Physiology Laboratory, Neurological Institute Cleveland Clinic, Cleveland, OH, 44106, USA. .,Department of Neurology and Neurosurgery, Johns Hopkins, Baltimore, MD, 21287, USA.
| | - Leah P Shriver
- Departments of Chemistry and Biology, University of Akron, Akron, OH, 44325, USA.
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