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Lee H, Fu JF, Gaudet K, Bryant AG, Price JC, Bennett RE, Johnson KA, Hyman BT, Hedden T, Salat DH, Yen YF, Huang SY. Aberrant vascular architecture in the hippocampus correlates with tau burden in mild cognitive impairment and Alzheimer's disease. J Cereb Blood Flow Metab 2024; 44:787-800. [PMID: 38000018 PMCID: PMC11197134 DOI: 10.1177/0271678x231216144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/04/2023] [Accepted: 10/21/2023] [Indexed: 11/26/2023]
Abstract
Cerebrovascular dysfunction is a significant contributor to Alzheimer's disease (AD) progression. AD mouse models show altered capillary morphology, density, and diminished blood flow in areas of tau and beta-amyloid accumulation. The purpose of this study was to examine alterations in vascular structure and their contributions to perfusion deficits in the hippocampus in AD and mild cognitive impairment (MCI). Seven individuals with AD and MCI (1 AD/6 MCI), nine cognitively intact older healthy adults, and seven younger healthy adults underwent pseudo-continuous arterial spin labeling (PCASL) and gradient-echo/spin-echo (GESE) dynamic susceptibility contrast (DSC) MRI. Cerebral blood flow (CBF), cerebral blood volume, relative vessel size index (rVSI), and mean vessel density were calculated from model fitting. Lower CBF from PCASL and SE DSC MRI was observed in the hippocampus of AD/MCI group. rVSI in the hippocampus of the AD/MCI group was larger than that of the two healthy groups (FDR-P = 0.02). No difference in vessel density was detected between the groups. We also explored relationship of tau burden from 18F-flortaucipir positron emission tomography and vascular measures from MRI. Tau burden was associated with larger vessel size and lower CBF in the hippocampus. We postulate that larger vessel size may be associated with vascular alterations in AD/MCI.
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Affiliation(s)
- Hansol Lee
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Jessie Fanglu Fu
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Kyla Gaudet
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Annie G Bryant
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Julie C Price
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Rachel E Bennett
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Keith A Johnson
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Center for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women’s Hospital, Boston, MA, USA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Trey Hedden
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - David H Salat
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Yi-Fen Yen
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Susie Y Huang
- Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
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Vestergaard SB, Damsbo AG, Pedersen NL, Zachariassen K, Drasbek KR, Østergaard L, Andersen G, Dalby RB, Mortensen JK. Exploring vascular contributions to cognitive impairment and dementia (ENIGMA): protocol for a prospective observational study. BMC Neurol 2024; 24:110. [PMID: 38570800 PMCID: PMC10988942 DOI: 10.1186/s12883-024-03601-7] [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: 12/20/2023] [Accepted: 03/15/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Post-stroke cognitive impairment (PSCI) is common. However, the underlying pathophysiology remains largely unknown. Understanding the role of microvascular changes and finding markers that can predict PSCI, could be a first step towards better screening and management of PSCI. Capillary dysfunction is a pathological feature of cerebral small vessel disease and may play a role in the mechanisms underlying PSCI. Extracellular vesicles (EVs) are secreted from cells and may act as disease biomarkers. We aim to investigate the role of capillary dysfunction in PSCI and the associations between EV characteristics and cognitive function one year after acute ischemic stroke (AIS) and transient ischemic attack (TIA). METHODS The ENIGMA study is a single-centre prospective clinical observational study conducted at Aarhus University Hospital, Denmark. Consecutive patients with AIS and TIA are included and followed for one year with follow-up visits at three and 12 months. An MRI is performed at 24 h and 12 months follow-up. EV characteristics will be characterised from blood samples drawn at 24 h and three months follow-up. Cognitive function is assessed three and 12 months after AIS and TIA using the Repeatable Battery for the Assessment of Neuropsychological Status. DISCUSSION Using novel imaging and molecular biological techniques the ENIGMA study will provide new knowledge about the vascular contributions to cognitive decline and dementia. TRIAL REGISTRATION The study is retrospectively registered as an ongoing observational study at ClinicalTrials.gov with the identifier NCT06257823.
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Affiliation(s)
- Sigrid Breinholt Vestergaard
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Andreas Gammelgaard Damsbo
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Niels Lech Pedersen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Neuroradiology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Katrine Zachariassen
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Kim Ryun Drasbek
- Department of Clinical Medicine Center of Functionally Integrative Neuroscience, Aarhus University, Universitetsbyen 3, Aarhus C, 8000, Denmark
| | - Leif Østergaard
- Department of Clinical Medicine Center of Functionally Integrative Neuroscience, Aarhus University, Universitetsbyen 3, Aarhus C, 8000, Denmark
| | - Grethe Andersen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Rikke Beese Dalby
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Radiology and Nuclear Medicine, University Hospital of Southern Denmark, Finsensgade 35, Esbjerg, 6700, Denmark
| | - Janne Kærgård Mortensen
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark.
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark.
- Department of Clinical Medicine, Department of Neurology, Aarhus University, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N, 8200, Denmark.
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3
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Yang C, Liu G, Zeng X, Xiang Y, Chen X, Le W. Therapeutic effects of long-term HBOT on Alzheimer's disease neuropathologies and cognitive impairment in APP swe/PS1 dE9 mice. Redox Biol 2024; 70:103006. [PMID: 38241837 PMCID: PMC10831255 DOI: 10.1016/j.redox.2023.103006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/01/2023] [Accepted: 12/18/2023] [Indexed: 01/21/2024] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder with the pathological hallmarks of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) in the brain. Although there is a hope that anti-amyloid monoclonal antibodies may emerge as a new therapy for AD, the high cost and side effect is a big concern. Non-drug therapy is attracting more attention and may provide a better resolution for the treatment of AD. Given the fact that hypoxia contributes to the pathogenesis of AD, hyperbaric oxygen therapy (HBOT) may be an effective intervention that can alleviate hypoxia and improve AD. However, it remains unclear whether long-term HBOT intervention in the early stage of AD can slow AD progression and ultimately prevent cognitive impairment in this disease. In this study we applied consecutive 3-month HBOT interventions on 3-month-old APPswe/PS1dE9 AD mice which represent the early stage of AD. When the APPswe/PS1dE9 mice at 9-month-old which represent the disease stage we measured cognitive function, 24-h blood oxygen saturation, Aβ and tau pathologies, vascular structure and function, and neuroinflammation in APPswe/PS1dE9 mice. Our results showed that long-term HBOT can attenuate the impairments in cognitive function observed in 9-month-old APPswe/PS1dE9 mice. Most importantly, HBOT effectively reduced the progression of Aβ plaques deposition, hyperphosphorylated tau protein aggregation, and neuronal and synaptic degeneration in the AD mice. Further, long-term HBOT was able to enhance blood oxygen saturation level. Besides, long-term HBOT can improve vascular structure and function, and reduce neuroinflammation in AD mice. This study is the first to demonstrate that long-term HBOT intervention in the early stage of AD can attenuate cognitive impairment and AD-like pathologies. Overall, these findings highlight the potential of long-term HBOT as a disease-modifying approach for AD treatment.
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Affiliation(s)
- Cui Yang
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Guangdong Liu
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xianrong Zeng
- Department of Hyperbaric Oxygen, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Yang Xiang
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xi Chen
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Weidong Le
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China.
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Hu Y, Zhang F, Ikonomovic M, Yang T. The Role of NRF2 in Cerebrovascular Protection: Implications for Vascular Cognitive Impairment and Dementia (VCID). Int J Mol Sci 2024; 25:3833. [PMID: 38612642 PMCID: PMC11012233 DOI: 10.3390/ijms25073833] [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: 02/03/2024] [Revised: 03/20/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024] Open
Abstract
Vascular cognitive impairment and dementia (VCID) represents a broad spectrum of cognitive decline secondary to cerebral vascular aging and injury. It is the second most common type of dementia, and the prevalence continues to increase. Nuclear factor erythroid 2-related factor 2 (NRF2) is enriched in the cerebral vasculature and has diverse roles in metabolic balance, mitochondrial stabilization, redox balance, and anti-inflammation. In this review, we first briefly introduce cerebrovascular aging in VCID and the NRF2 pathway. We then extensively discuss the effects of NRF2 activation in cerebrovascular components such as endothelial cells, vascular smooth muscle cells, pericytes, and perivascular macrophages. Finally, we summarize the clinical potential of NRF2 activators in VCID.
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Affiliation(s)
- Yizhou Hu
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15216, USA; (Y.H.); (F.Z.); (M.I.)
- Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh, Pittsburgh, PA 15216, USA
- Department of Internal Medicine, University of Pittsburgh Medical Center (UPMC) McKeesport, McKeesport, PA 15132, USA
| | - Feng Zhang
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15216, USA; (Y.H.); (F.Z.); (M.I.)
- Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh, Pittsburgh, PA 15216, USA
| | - Milos Ikonomovic
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15216, USA; (Y.H.); (F.Z.); (M.I.)
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15216, USA
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA
| | - Tuo Yang
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15216, USA; (Y.H.); (F.Z.); (M.I.)
- Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh, Pittsburgh, PA 15216, USA
- Department of Internal Medicine, University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA 15216, USA
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García-Culebras A, Cuartero MI, Peña-Martínez C, Moraga A, Vázquez-Reyes S, de Castro-Millán FJ, Cortes-Canteli M, Lizasoain I, Moro MÁ. Myeloid cells in vascular dementia and Alzheimer's disease: Possible therapeutic targets? Br J Pharmacol 2024; 181:777-798. [PMID: 37282844 DOI: 10.1111/bph.16159] [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: 03/19/2023] [Revised: 05/10/2023] [Accepted: 05/20/2023] [Indexed: 06/08/2023] Open
Abstract
Growing evidence supports the suggestion that the peripheral immune system plays a role in different pathologies associated with cognitive impairment, such as vascular dementia (VD) or Alzheimer's disease (AD). The aim of this review is to summarize, within the peripheral immune system, the implications of different types of myeloid cells in AD and VD, with a special focus on post-stroke cognitive impairment and dementia (PSCID). We will review the contributions of the myeloid lineage, from peripheral cells (neutrophils, platelets, monocytes and monocyte-derived macrophages) to central nervous system (CNS)-associated cells (perivascular macrophages and microglia). Finally, we will evaluate different potential strategies for pharmacological modulation of pathological processes mediated by myeloid cell subsets, with an emphasis on neutrophils, their interaction with platelets and the process of immunothrombosis that triggers neutrophil-dependent capillary stall and hypoperfusion, as possible effector mechanisms that may pave the way to novel therapeutic avenues to stop dementia, the epidemic of our time. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.
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Affiliation(s)
- Alicia García-Culebras
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Departamento de Biología Celular, Facultad de Medicina, UCM, Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
| | - María Isabel Cuartero
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
| | - Carolina Peña-Martínez
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
| | - Ana Moraga
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Departamento de Biología Celular, Facultad de Medicina, UCM, Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain
| | - Sandra Vázquez-Reyes
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
| | - Francisco Javier de Castro-Millán
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
| | - Marta Cortes-Canteli
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Madrid, Spain
| | - Ignacio Lizasoain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain
| | - María Ángeles Moro
- Cardiovascular Risk Factor and Brain Function Programme, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Unidad de Investigación Neurovascular, Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Madrid, Spain
- Instituto Universitario de Investigación en Neuroquímica, UCM, Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain
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Wheeler KV, Irimia A, Braskie MN. Using Neuroimaging to Study Cerebral Amyloid Angiopathy and Its Relationship to Alzheimer's Disease. J Alzheimers Dis 2024; 97:1479-1502. [PMID: 38306032 DOI: 10.3233/jad-230553] [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] [Indexed: 02/03/2024]
Abstract
Cerebral amyloid angiopathy (CAA) is characterized by amyloid-β aggregation in the media and adventitia of the leptomeningeal and cortical blood vessels. CAA is one of the strongest vascular contributors to Alzheimer's disease (AD). It frequently co-occurs in AD patients, but the relationship between CAA and AD is incompletely understood. CAA may drive AD risk through damage to the neurovascular unit and accelerate parenchymal amyloid and tau deposition. Conversely, early AD may also drive CAA through cerebrovascular remodeling that impairs blood vessels from clearing amyloid-β. Sole reliance on autopsy examination to study CAA limits researchers' ability to investigate CAA's natural disease course and the effect of CAA on cognitive decline. Neuroimaging allows for in vivo assessment of brain function and structure and can be leveraged to investigate CAA staging and explore its associations with AD. In this review, we will discuss neuroimaging modalities that can be used to investigate markers associated with CAA that may impact AD vulnerability including hemorrhages and microbleeds, blood-brain barrier permeability disruption, reduced cerebral blood flow, amyloid and tau accumulation, white matter tract disruption, reduced cerebrovascular reactivity, and lowered brain glucose metabolism. We present possible areas for research inquiry to advance biomarker discovery and improve diagnostics.
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Affiliation(s)
- Koral V Wheeler
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina Del Rey, CA, USA
| | - Andrei Irimia
- Ethel Percy Andrus Gerontology Center, USC Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
- Department of Biomedical Engineering, Corwin D. Denney Research Center, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Meredith N Braskie
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina Del Rey, CA, USA
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Madsen LS, Kjeldsen PL, Ismail R, Parbo P, Østergaard L, Brooks DJ, Eskildsen SF. Capillary dysfunction in healthy elderly APOE ε4 carriers with raised brain Aβ deposition. Alzheimers Dement 2024; 20:459-471. [PMID: 37679610 PMCID: PMC10917038 DOI: 10.1002/alz.13461] [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: 06/09/2023] [Revised: 07/26/2023] [Accepted: 08/13/2023] [Indexed: 09/09/2023]
Abstract
INTRODUCTION Capillary dysfunction, characterized by disturbances in capillary blood flow distribution, might be an overlooked factor in the development of Alzheimer's disease (AD). This study investigated microvascular blood flow in preclinical and prodromal AD individuals. METHODS Using dynamic susceptibility contrast magnetic resonance imaging and positron emission tomography, we examined alterations in microvascular circulation and levels of Aβ deposition in two independent cohorts of APOE ε4 carriers. RESULTS Capillary dysfunction was elevated in both prodromal and preclinical AD individuals compared to age-matched controls. Additionally, the prodromal group exhibited higher levels of capillary dysfunction compared to the preclinical group. DISCUSSION These findings suggest that capillary dysfunction can be detected at the preclinical stage of AD and indicates a worsening of capillary dysfunction throughout the AD continuum. Understanding the interaction between capillary dysfunction and Aβ could provide insights into the relationship between cardiovascular risk factors and the development of AD. HIGHLIGHTS Alzheimer's disease (AD) is associated with disturbances in microvascular circulation. Capillary dysfunction can be detected in preclinical AD. As cognitive symptoms progress in prodromal AD, capillary dysfunction worsens. Capillary dysfunction may impede the clearance of beta-amyloid (Aβ). Capillary dysfunction might contribute to the development of AD.
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Affiliation(s)
- Lasse S. Madsen
- Center of Functionally Integrative NeuroscienceDepartment of Clinical MedicineAarhus UniversityAarhusDenmark
- Department of Nuclear Medicine and PET‐CentreAarhus University HospitalAarhusDenmark
| | - Pernille L. Kjeldsen
- Department of Nuclear Medicine and PET‐CentreAarhus University HospitalAarhusDenmark
| | - Rola Ismail
- Department of Nuclear MedicineSygehus LillebaeltVejleDenmark
| | - Peter Parbo
- Department of Nuclear MedicineOdense University HospitalOdenseDenmark
| | - Leif Østergaard
- Center of Functionally Integrative NeuroscienceDepartment of Clinical MedicineAarhus UniversityAarhusDenmark
- Department of NeuroradiologyAarhus University HospitalAarhusDenmark
| | - David J. Brooks
- Department of Nuclear Medicine and PET‐CentreAarhus University HospitalAarhusDenmark
- Institute of Translational and Clinical ResearchUniversity of Newcastle upon TyneNewcastle upon TyneUK
| | - Simon F. Eskildsen
- Center of Functionally Integrative NeuroscienceDepartment of Clinical MedicineAarhus UniversityAarhusDenmark
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You TY, Dong Q, Cui M. Emerging Links between Cerebral Blood Flow Regulation and Cognitive Decline: A Role for Brain Microvascular Pericytes. Aging Dis 2023:AD.2022.1204. [PMID: 37163446 PMCID: PMC10389833 DOI: 10.14336/ad.2022.1204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 12/04/2022] [Indexed: 05/12/2023] Open
Abstract
Cognitive impairment associated with vascular etiology has been of considerable interest in the development of dementia. Recent studies have started to uncover cerebral blood flow deficits in initiating cognitive deterioration. Brain microvascular pericytes, the only type of contractile cells in capillaries, are involved in the precise modulation of vascular hemodynamics due to their ability to regulate resistance in the capillaries. They exhibit potential in maintaining the capillary network geometry and basal vascular tone. In addition, pericytes can facilitate better blood flow supply in response to neurovascular coupling. Their dysfunction is thought to disturb cerebral blood flow causing metabolic imbalances or structural injuries, leading to consequent cognitive decline. In this review, we summarize the characteristics of microvascular pericytes in brain blood flow regulation and outline the framework of a two-hit hypothesis in cognitive decline, where we emphasize how pericytes serve as targets of cerebral blood flow dysregulation that occurs with neurological challenges, ranging from genetic factors, aging, and pathological proteins to ischemic stress.
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Affiliation(s)
- Tong-Yao You
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Qiang Dong
- Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- National Center for Neurological Disorders, Huashan Hospital, Fudan University, Shanghai, China
| | - Mei Cui
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
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Liu G, Yang C, Wang X, Chen X, Wang Y, Le W. Oxygen metabolism abnormality and Alzheimer's disease: An update. Redox Biol 2023; 68:102955. [PMID: 37956598 PMCID: PMC10665957 DOI: 10.1016/j.redox.2023.102955] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/13/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023] Open
Abstract
Oxygen metabolism abnormality plays a crucial role in the pathogenesis of Alzheimer's disease (AD) via several mechanisms, including hypoxia, oxidative stress, and mitochondrial dysfunction. Hypoxia condition usually results from living in a high-altitude habitat, cardiovascular and cerebrovascular diseases, and chronic obstructive sleep apnea. Chronic hypoxia has been identified as a significant risk factor for AD, showing an aggravation of various pathological components of AD, such as amyloid β-protein (Aβ) metabolism, tau phosphorylation, mitochondrial dysfunction, and neuroinflammation. It is known that hypoxia and excessive hyperoxia can both result in oxidative stress and mitochondrial dysfunction. Oxidative stress and mitochondrial dysfunction can increase Aβ and tau phosphorylation, and Aβ and tau proteins can lead to redox imbalance, thus forming a vicious cycle and exacerbating AD pathology. Hyperbaric oxygen therapy (HBOT) is a non-invasive intervention known for its capacity to significantly enhance cerebral oxygenation levels, which can significantly attenuate Aβ aggregation, tau phosphorylation, and neuroinflammation. However, further investigation is imperative to determine the optimal oxygen pressure, duration of exposure, and frequency of HBOT sessions. In this review, we explore the prospects of oxygen metabolism in AD, with the aim of enhancing our understanding of the underlying molecular mechanisms in AD. Current research aimed at attenuating abnormalities in oxygen metabolism holds promise for providing novel therapeutic approaches for AD.
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Affiliation(s)
- Guangdong Liu
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Cui Yang
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xin Wang
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xi Chen
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yanjiang Wang
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
| | - Weidong Le
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China; Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian, 116021, China.
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Ito S, Yagi R, Ogata S, Masuda T, Saito T, Saido T, Ohtsuki S. Proteomic alterations in the brain and blood-brain barrier during brain Aβ accumulation in an APP knock-in mouse model of Alzheimer's disease. Fluids Barriers CNS 2023; 20:66. [PMID: 37705104 PMCID: PMC10500766 DOI: 10.1186/s12987-023-00466-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/02/2023] [Indexed: 09/15/2023] Open
Abstract
BACKGROUND Blood-brain barrier (BBB) dysfunction is supposed to be an early event in the development of Alzheimer's disease (AD). This study aimed to investigate the relationship between BBB alterations and AD progression in terms of amyloid-β peptide (Aβ) accumulation in the brains of humanized amyloid precursor protein knock-in (APP-KI) mice. METHODS Brain Aβ accumulation was examined using immunohistochemical analysis. Alterations in differentially expressed proteins were determined using sequential window acquisition of all theoretical fragment ion mass spectroscopy (SWATH-MS)-based quantitative proteomics, and Metascape, STRING, Gene Ontology, and KEGG were used for network analyses of altered biological pathways and processes. Statistical significance was determined using the unpaired two-tailed Student's t-test and Welch's t-test for two groups and one-way analysis of variance followed by Tukey's test for more than two groups. Correlations between two groups were determined using Pearson's correlation analysis. RESULTS Brain Aβ accumulation in APP-KI mice was detectable at 2 months, increased significantly at 5 months, and remained elevated at 12 months of age. The levels of differentially expressed proteins in isolated brain capillaries were higher in younger mice, whereas those in the brain were higher in older mice. Network analyses indicated changes in basement membrane-associated and ribosomal proteins in the brain capillaries. There were no significant changes in key proteins involved in drug or Aβ transport at the BBB. In contrast, solute carrier transporter levels in astrocytes, microglia, and neurons were altered in the brain of older mice. Moreover, the levels of the lipid transporters Apoe and Apoj were upregulated in both the brain and isolated brain capillaries after Aβ accumulation. CONCLUSIONS Our results suggest that changes in the brain occurred after advanced Aβ accumulation, whereas initial Aβ accumulation was sufficient to cause alterations in the BBB. These findings may help elucidate the role of BBB alterations in AD progression and predict the distribution of drugs across the BBB in the brain of patients with AD.
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Affiliation(s)
- Shingo Ito
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
| | - Ryotaro Yagi
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Seiryo Ogata
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
- Department of Environmental Medicine and Molecular Toxicology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Takeshi Masuda
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Sumio Ohtsuki
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
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11
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Su M, Nizamutdinov D, Liu H, Huang JH. Recent Mechanisms of Neurodegeneration and Photobiomodulation in the Context of Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24119272. [PMID: 37298224 DOI: 10.3390/ijms24119272] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease and the world's primary cause of dementia, a condition characterized by significant progressive declines in memory and intellectual capacities. While dementia is the main symptom of Alzheimer's, the disease presents with many other debilitating symptoms, and currently, there is no known treatment exists to stop its irreversible progression or cure the disease. Photobiomodulation has emerged as a very promising treatment for improving brain function, using light in the range from red to the near-infrared spectrum depending on the application, tissue penetration, and density of the target area. The goal of this comprehensive review is to discuss the most recent achievements in and mechanisms of AD pathogenesis with respect to neurodegeneration. It also provides an overview of the mechanisms of photobiomodulation associated with AD pathology and the benefits of transcranial near-infrared light treatment as a potential therapeutic solution. This review also discusses the older reports and hypotheses associated with the development of AD, as well as some other approved AD drugs.
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Affiliation(s)
- Matthew Su
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Damir Nizamutdinov
- Department of Neurosurgery, College of Medicine, Texas A&M University, Temple, TX 76508, USA
- Department of Neurosurgery, Neuroscience Institute, Baylor Scott and White Health, Temple, TX 76508, USA
| | - Hanli Liu
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010, USA
| | - Jason H Huang
- Department of Neurosurgery, College of Medicine, Texas A&M University, Temple, TX 76508, USA
- Department of Neurosurgery, Neuroscience Institute, Baylor Scott and White Health, Temple, TX 76508, USA
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12
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Salminen A. Activation of aryl hydrocarbon receptor (AhR) in Alzheimer's disease: role of tryptophan metabolites generated by gut host-microbiota. J Mol Med (Berl) 2023; 101:201-222. [PMID: 36757399 PMCID: PMC10036442 DOI: 10.1007/s00109-023-02289-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/19/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023]
Abstract
Gut microbiota in interaction with intestinal host tissues influences many brain functions and microbial dysbiosis has been linked with brain disorders, such as neuropsychiatric conditions and Alzheimer's disease (AD). L-tryptophan metabolites and short-chained fatty acids (SCFA) are major messengers in the microbiota-brain axis. Aryl hydrocarbon receptors (AhR) are main targets of tryptophan metabolites in brain microvessels which possess an enriched expression of AhR protein. The Ah receptor is an evolutionarily conserved, ligand-activated transcription factor which is not only a sensor of xenobiotic toxins but also a pleiotropic regulator of both developmental processes and age-related tissue degeneration. Major microbiota-produced tryptophan metabolites involve indole derivatives, e.g., indole 3-pyruvic acid, indole 3-acetaldehyde, and indoxyl sulfate, whereas indoleamine and tryptophan 2,3-dioxygenases (IDO/TDO) of intestine host cells activate the kynurenine (KYN) pathway generating KYN metabolites, many of which are activators of AhR signaling. Chronic kidney disease (CKD) increases the serum level of indoxyl sulfate which promotes AD pathogenesis, e.g., it disrupts integrity of blood-brain barrier (BBB) and impairs cognitive functions. Activation of AhR signaling disturbs vascular homeostasis in brain; (i) it controls blood flow via the renin-angiotensin system, (ii) it inactivates endothelial nitric oxide synthase (eNOS), thus impairing NO production and vasodilatation, and (iii) it induces oxidative stress, stimulates inflammation, promotes cellular senescence, and enhances calcification of vascular walls. All these alterations are evident in cerebral amyloid angiopathy (CAA) in AD pathology. Moreover, AhR signaling can disturb circadian regulation and probably affect glymphatic flow. It seems plausible that dysbiosis of gut microbiota impairs the integrity of BBB via the activation of AhR signaling and thus aggravates AD pathology. KEY MESSAGES: Dysbiosis of gut microbiota is associated with dementia and Alzheimer's disease. Tryptophan metabolites are major messengers from the gut host-microbiota to brain. Tryptophan metabolites activate aryl hydrocarbon receptor (AhR) signaling in brain. The expression of AhR protein is enriched in brain microvessels and blood-brain barrier. Tryptophan metabolites disturb brain vascular integrity via AhR signaling. Dysbiosis of gut microbiota promotes inflammation and AD pathology via AhR signaling.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, Kuopio, 70211, Finland.
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13
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Ruiz-Uribe NE, Bracko O, Swallow M, Omurzakov A, Dash S, Uchida H, Xiang D, Haft-Javaherian M, Falkenhain K, Lamont ME, Ali M, Njiru BN, Chang HY, Tan AY, Xiang JZ, Iadecola C, Park L, Sanchez T, Nishimura N, Schaffer CB. Vascular oxidative stress causes neutrophil arrest in brain capillaries, leading to decreased cerebral blood flow and contributing to memory impairment in a mouse model of Alzheimer’s disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528710. [PMID: 36824768 PMCID: PMC9949082 DOI: 10.1101/2023.02.15.528710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
INTRODUCTION In this study, we explore the role of oxidative stress produced by NOX2-containing NADPH oxidase as a molecular mechanism causing capillary stalling and cerebral blood flow deficits in the APP/PS1 mouse model of AD. METHODS We inhibited NOX2 in APP/PS1 mice by administering a 10 mg/kg dose of the peptide inhibitor gp91-ds-tat i.p., for two weeks. We used in vivo two-photon imaging to measure capillary stalling, penetrating arteriole flow, and vascular inflammation. We also characterized short-term memory function and gene expression changes in cerebral microvessels. RESULTS We found that after NOX2 inhibition capillary stalling, as well as parenchymal and vascular inflammation, were significantly reduced. In addition, we found a significant increase in penetrating arteriole flow, followed by an improvement in short-term memory, and downregulation of inflammatory gene expression pathways. DISCUSSION Oxidative stress is a major mechanism leading to microvascular dysfunction in AD, and represents an important therapeutic target.
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14
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Barnes JN, Burns JM, Bamman MM, Billinger SA, Bodine SC, Booth FW, Brassard P, Clemons TA, Fadel PJ, Geiger PC, Gujral S, Haus JM, Kanoski SE, Miller BF, Morris JK, O’Connell KM, Poole DC, Sandoval DA, Smith JC, Swerdlow RH, Whitehead SN, Vidoni ED, van Praag H. Proceedings from the Albert Charitable Trust Inaugural Workshop on 'Understanding the Acute Effects of Exercise on the Brain'. Brain Plast 2022; 8:153-168. [PMID: 36721393 PMCID: PMC9837736 DOI: 10.3233/bpl-220146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2022] [Indexed: 12/12/2022] Open
Abstract
An inaugural workshop supported by "The Leo and Anne Albert Charitable Trust," was held October 4-7, 2019 in Scottsdale, Arizona, to focus on the effects of exercise on the brain and to discuss how physical activity may prevent or delay the onset of aging-related neurodegenerative conditions. The Scientific Program Committee (led by Dr. Jeff Burns) assembled translational, clinical, and basic scientists who research various aspects of the effects of exercise on the body and brain, with the overall goal of gaining a better understanding as to how to delay or prevent neurodegenerative diseases. In particular, research topics included the links between cardiorespiratory fitness, the cerebrovasculature, energy metabolism, peripheral organs, and cognitive function, which are all highly relevant to understanding the effects of acute and chronic exercise on the brain. The Albert Trust workshop participants addressed these and related topics, as well as how other lifestyle interventions, such as diet, affect age-related cognitive decline associated with Alzheimer's and other neurodegenerative diseases. This report provides a synopsis of the presentations and discussions by the participants, and a delineation of the next steps towards advancing our understanding of the effects of exercise on the aging brain.
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Affiliation(s)
- Jill N. Barnes
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Jeffrey M. Burns
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, USA
| | - Marcas M. Bamman
- UAB Center for Exercise Medicine, University of Alabama, Birmingham, AL, USA
| | | | - Sue C. Bodine
- Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Frank W. Booth
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, and Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec city, QC, Canada
| | - Tameka A. Clemons
- Department of Professional and Medical Education, Meharry Medical College, Nashville, TN, USA
| | - Paul J. Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, USA
| | - Paige C. Geiger
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Swathi Gujral
- University of Pittsburgh School of Medicine, Department of Psychiatry, Pittsburgh, PA, USA
| | - Jacob M. Haus
- School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Scott E. Kanoski
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsrife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, USA
| | - Benjamin F. Miller
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Jill K. Morris
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, USA
| | | | - David C. Poole
- Departments of Kinesiology, Anatomy and Physiology, Kansas State University, Manhattan, KS, USA
| | | | - J. Carson Smith
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, MD, USA
| | | | - Shawn N. Whitehead
- Vulnerable Brain Laboratory, Department Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, N6A 5C1, Canada
| | - Eric D. Vidoni
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, USA
| | - Henriette van Praag
- Stiles-Nicholson Brain Institute, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter FL, USA
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15
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Murrant CL, Fletcher NM. Capillary communication: the role of capillaries in sensing the tissue environment, coordinating the microvascular, and controlling blood flow. Am J Physiol Heart Circ Physiol 2022; 323:H1019-H1036. [PMID: 36149771 DOI: 10.1152/ajpheart.00088.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Historically, capillaries have been viewed as the microvascular site for flux of nutrients to cells and removal of waste products. Capillaries are the most numerous blood vessel segment within the tissue, whose vascular wall consists of only a single layer of endothelial cells and are situated within microns of each cell of the tissue, all of which optimizes capillaries for the exchange of nutrients between the blood compartment and the interstitial space of tissues. There is, however, a growing body of evidence to support that capillaries play an important role in sensing the tissue environment, coordinating microvascular network responses, and controlling blood flow. Much of our growing understanding of capillaries stems from work in skeletal muscle and more recent work in the brain, where capillaries can be stimulated by products released from cells of the tissue during increased activity and are able to communicate with upstream and downstream vascular segments, enabling capillaries to sense the activity levels of the tissue and send signals to the microvascular network to coordinate the blood flow response. This review will focus on the emerging role that capillaries play in communication between cells of the tissue and the vascular network required to direct blood flow to active cells in skeletal muscle and the brain. We will also highlight the emerging central role that disruptions in capillary communication may play in blood flow dysregulation, pathophysiology, and disease.
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Affiliation(s)
- Coral L Murrant
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Nicole M Fletcher
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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16
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Katsel P, Fam P, Tan W, Khan S, Gama-Sosa M, De Gasperi R, Roussos P, Robinson A, Cooper I, Schnaider-Beeri M, Haroutunian V. Engagement of vascular early response genes typifies mild cognitive impairment. Alzheimers Dement 2022; 18:1357-1369. [PMID: 34758195 PMCID: PMC10878080 DOI: 10.1002/alz.12481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 07/07/2021] [Accepted: 08/11/2021] [Indexed: 11/12/2022]
Abstract
INTRODUCTION Molecular responses in the brains of persons with mild cognitive impairment (MCI), the earliest transitional state between normal aging and early Alzheimer's disease (AD), are poorly understood. METHODS We examined AD-related neuropathology and transcriptome changes in the neocortex of individuals with MCI relative to controls and temporal responses to the mild hypoxia in mouse brains. RESULTS Subsets of vascular early response to hypoxia genes were upregulated in MCI prior to the buildup of AD neuropathology. Early activation of pro-angiogenic hypoxia-inducible factor signaling in response to mild hypoxia was detected in mouse brains similar to those that were altered in MCI. Protracted responses to hypoxia were characterized by activation of phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt)-the mammalian target of rapamycin (mTOR) pathways in brain microvessel isolates. DISCUSSION These findings suggest that cerebrovascular remodeling is an important antecedent to the development of dementia and a component of the homeostatic response to reduced oxygen tension in aging prior to the onset of AD.
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Affiliation(s)
- Pavel Katsel
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
| | - Peter Fam
- Department of Neuroscience, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
| | - Weilun Tan
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
| | - Sonia Khan
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
| | - Miguel Gama-Sosa
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
| | - Rita De Gasperi
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
| | - Panos Roussos
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
- Genetics and Genomic Sciences, The Icahn School of Medicine
at Mount Sinai, New York, New York, USA
- Pamela Sklar Division of Psychiatric Genomics and Friedman
Brain Institute, The Icahn School of Medicine at Mount Sinai, New York, New York,
USA
| | - Ari Robinson
- The Joseph Sagol Neuroscience Center Tel-Hashomer,
Ramat-Gan, Israel
| | - Itzik Cooper
- The Joseph Sagol Neuroscience Center Tel-Hashomer,
Ramat-Gan, Israel
| | - Michal Schnaider-Beeri
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
- The Joseph Sagol Neuroscience Center Tel-Hashomer,
Ramat-Gan, Israel
| | - Vahram Haroutunian
- Department of Psychiatry, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
- Department of Neuroscience, The Icahn School of Medicine at
Mount Sinai, New York, New York, USA
- Mental Illness Research, Education and Clinical Center
(MIRECC), James J Peters VA Medical Center, Bronx, New York, USA
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17
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Zhu WM, Neuhaus A, Beard DJ, Sutherland BA, DeLuca GC. Neurovascular coupling mechanisms in health and neurovascular uncoupling in Alzheimer's disease. Brain 2022; 145:2276-2292. [PMID: 35551356 PMCID: PMC9337814 DOI: 10.1093/brain/awac174] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 11/25/2022] Open
Abstract
To match the metabolic demands of the brain, mechanisms have evolved to couple neuronal activity to vasodilation, thus increasing local cerebral blood flow and delivery of oxygen and glucose to active neurons. Rather than relying on metabolic feedback signals such as the consumption of oxygen or glucose, the main signalling pathways rely on the release of vasoactive molecules by neurons and astrocytes, which act on contractile cells. Vascular smooth muscle cells and pericytes are the contractile cells associated with arterioles and capillaries, respectively, which relax and induce vasodilation. Much progress has been made in understanding the complex signalling pathways of neurovascular coupling, but issues such as the contributions of capillary pericytes and astrocyte calcium signal remain contentious. Study of neurovascular coupling mechanisms is especially important as cerebral blood flow dysregulation is a prominent feature of Alzheimer’s disease. In this article we will discuss developments and controversies in the understanding of neurovascular coupling and finish by discussing current knowledge concerning neurovascular uncoupling in Alzheimer’s disease.
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Affiliation(s)
- Winston M Zhu
- Oxford Medical School, University of Oxford, Oxford, UK
| | - Ain Neuhaus
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Daniel J Beard
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Brad A Sutherland
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Gabriele C DeLuca
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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18
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Xie J, Cheng Z, Gu L, Wu B, Zhang G, Shiu W, Chen R, Wang Z, Liu C, Tu J, Cai X, Liu J, Zhang Z. Evaluation of cerebrovascular hemodynamics in vascular dementia patients with a new individual computational fluid dynamics algorithm. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 213:106497. [PMID: 34749243 DOI: 10.1016/j.cmpb.2021.106497] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Cerebral hemodynamic disorders are involved in the occurrence and progression of vascular dementia (VaD), but the methods to detect hemodynamics remainmultifarious and uncertain nowadays. We aim to exploit a computational fluid dynamics (CFD) approach by static and dynamic parameters, which can be used to detect individual cerebrovascular hemodynamics quantitatively. METHODS A patient-specific CFD model was constructed with geometrical arteries on the magnetic resonance angiography (MRA) and hemodynamic parameters on ultrasound Doppler, by which, the structural and simulated hemodynamic indexes could be obtained, mainly including the cerebral arterial volume (CAV), the number of visible arterial outlets, the total cerebral blood flow (tCBF) index and the total cerebrovascular resistance (tCVR) index. The hemodynamics were detected in subcortical vascular dementia (SVaD) patients (n = 38) and cognitive normal controls (CNCs; n = 40). RESULTS Compared with CNCs, the SVaD patients had reduced outlets, CAV and tCBF index (all P ≤ 0.001), increased volume of white matter hyperintensity (WMH) and tCVR index (both P ≤ 0.01). The fewer outlets (OR = 0.77), higher Hachinski ischemic score (HIS) (OR = 3.65), increased tCVR index (OR = 1.98) and volume of WMH (OR = 1.12) were independently associated with SVaD. All hemodynamic parameters could differentiate the SVaD patinets and CNCs, especially the composite index calculated by outlets, tCVR index and HIS (AUC = 0.943). Fewer outlets and more WMH increased the odds of SVaD, which were partly mediated by the tCBF index (14.4% and 13.0%, respectively). CONCLUSION The reduced outlets, higher HIS and tCVR index may be independent risk factors for the SVaD, and a combination of these indexes can differentiate SVaD patients and CNCs reliably. The tCBF index potentially mediates the relationships between hemodynamic indexes and SVaD. Although all simulated indexes only represented the true hemodynamics indirectly, this CFD model can provide patient-specific hemodynamic alterations non-invasively and conveniently.
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Affiliation(s)
- Jian Xie
- Department of Neurology, Key Laboratory of Developmental Genes and Human Disease, Affiliated ZhongDa Hospital, School of Medicine, Institution of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China
| | - Zaiheng Cheng
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Lihua Gu
- Department of Neurology, Key Laboratory of Developmental Genes and Human Disease, Affiliated ZhongDa Hospital, School of Medicine, Institution of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China
| | - Bokai Wu
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Gaojia Zhang
- Department of Neurology, Key Laboratory of Developmental Genes and Human Disease, Affiliated ZhongDa Hospital, School of Medicine, Institution of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China
| | - Wenshin Shiu
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Rongliang Chen
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Zan Wang
- Department of Neurology, Key Laboratory of Developmental Genes and Human Disease, Affiliated ZhongDa Hospital, School of Medicine, Institution of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China
| | - Chang Liu
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Jie Tu
- The Brain Cognition and Brain Disease institute of Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Xiaochuan Cai
- Department of Computer Science, University of Colorado Boulder, United States
| | - Jia Liu
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China.
| | - Zhijun Zhang
- Department of Neurology, Key Laboratory of Developmental Genes and Human Disease, Affiliated ZhongDa Hospital, School of Medicine, Institution of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China; The Brain Cognition and Brain Disease institute of Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China; Research Center for Brain Health, Pazhou Lab, Guangzhou, Guangdong 510330, China.
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19
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Dalby RB, Eskildsen SF, Videbech P, Rosenberg R, Østergaard L. Cerebral hemodynamics and capillary dysfunction in late-onset major depressive disorder. Psychiatry Res Neuroimaging 2021; 317:111383. [PMID: 34508953 DOI: 10.1016/j.pscychresns.2021.111383] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 08/22/2021] [Accepted: 08/31/2021] [Indexed: 02/06/2023]
Abstract
In major depressive disorder (MDD), perfusion changes in cortico-limbic pathways are interpreted as altered neuronal activity, but they could also signify changes in neurovascular coupling due to altered capillary function. To examine capillary function in late-onset MDD, 22 patients and 22 age- and gender-matched controls underwent perfusion MRI. We measured normalized cerebral blood flow (nCBF), cerebral blood volume (nCBV), and relative transit-time heterogeneity (RTH). Resulting brain oxygenation was estimated in terms of oxygen tension and normalized metabolic rate of oxygen (nCMRO2). Patients revealed signs of capillary dysfunction (elevated RTH) in the anterior prefrontal cortex and ventral anterior cingulate cortex bilaterally and in the left insulate cortex compared to controls, bilateral hypometabolism (parallel reductions of nCBV, nCBF, and CMRO2) but preserved capillary function in the subthalamic nucleus and globus pallidus bilaterally, and hyperactivity with preserved capillary function (increased nCBF) in the cerebellum and brainstem. Our data support that perfusion changes in deep nuclei and cerebellum reflect abnormally low and high activity, respectively, in MDD patients, but suggest that microvascular pathology affects neurovascular coupling in ventral circuits. We speculate that microvascular pathology is important for our understanding of etiology of late-onset MDD as well as infererences about resulting brain activity changes.
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Affiliation(s)
- Rikke B Dalby
- Center of Functionally Integrative Neuroscience (CFIN) / MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark; Department of Radiology, Section of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark.
| | - Simon F Eskildsen
- Center of Functionally Integrative Neuroscience (CFIN) / MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Poul Videbech
- Center for Neuropsychiatric Depression Research, Mental Health Center Glostrup, Glostrup, Denmark
| | - Raben Rosenberg
- Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark; Centre of Psychiatry Amager, Mental Health Services in the Capital Region of Denmark, Copenhagen, Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN) / MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Neuroradiology Research Unit, Department of Radiology, Section of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark
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20
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Raimondo L, Knapen T, Oliveira ĹAF, Yu X, Dumoulin SO, van der Zwaag W, Siero JCW. A line through the brain: implementation of human line-scanning at 7T for ultra-high spatiotemporal resolution fMRI. J Cereb Blood Flow Metab 2021; 41:2831-2843. [PMID: 34415208 PMCID: PMC8756483 DOI: 10.1177/0271678x211037266] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Functional magnetic resonance imaging (fMRI) is a widely used tool in neuroscience to detect neurally evoked responses, e.g. the blood oxygenation level-dependent (BOLD) signal. Typically, BOLD fMRI has millimeter spatial resolution and temporal resolution of one to few seconds. To study the sub-millimeter structures and activity of the cortical gray matter, the field needs an fMRI method with high spatial and temporal resolution. Line-scanning fMRI achieves very high spatial resolution and high sampling rate, at the cost of a sacrifice in volume coverage. Here, we present a human line-scanning implementation on a 7T MRI system. First, we investigate the quality of the saturation pulses that suppress MR signal outside the line. Second, we established the best coil combination for reconstruction. Finally, we applied the line-scanning method in the occipital lobe during a visual stimulation task, showing BOLD responses along cortical depth, every 250 µm with a 200 ms repetition time (TR). We found a good correspondence of t-statistics values with 2D gradient-echo echo planar imaging (GE-EPI) BOLD fMRI data with the same temporal resolution and voxel volume (R = 0.6 ± 0.2). In summary, we demonstrate the feasibility of line-scanning in humans and this opens line-scanning fMRI for applications in cognitive and clinical neuroscience.
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Affiliation(s)
- Luisa Raimondo
- Spinoza Centre for Neuroimaging, Amsterdam, Netherlands.,Experimental and Applied Psychology, VU University, Amsterdam, Netherlands
| | - Tomas Knapen
- Spinoza Centre for Neuroimaging, Amsterdam, Netherlands.,Experimental and Applied Psychology, VU University, Amsterdam, Netherlands
| | - Ĺcaro A F Oliveira
- Spinoza Centre for Neuroimaging, Amsterdam, Netherlands.,Experimental and Applied Psychology, VU University, Amsterdam, Netherlands
| | - Xin Yu
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - Serge O Dumoulin
- Spinoza Centre for Neuroimaging, Amsterdam, Netherlands.,Experimental and Applied Psychology, VU University, Amsterdam, Netherlands.,Experimental Psychology, 8125Utrecht University, Utrecht University, Utrecht, Netherlands
| | | | - Jeroen C W Siero
- Spinoza Centre for Neuroimaging, Amsterdam, Netherlands.,Radiology, Centre for Image Sciences, University Medical Centre Utrecht, Utrecht, Netherlands
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21
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Abstract
Alzheimer disease (AD) is the most common type of dementia characterized by the progressive cognitive and social decline. Clinical drug targets have heavily focused on the amyloid hypothesis, with amyloid beta (Aβ), and tau proteins as key pathophysiologic markers of AD. However, no effective treatment has been developed so far, which prompts researchers to focus on other aspects of AD beyond Aβ, and tau proteins. Additionally, there is a mounting epidemiologic evidence that various environmental factors influence the development of dementia and that dementia etiology is likely heterogenous. In the past decades, new risk factors or potential etiologies have been widely studied. Here, we review several novel epidemiologic and clinical research developments that focus on sleep, hypoxia, diet, gut microbiota, and hearing impairment and their links to AD published in recent years. At the frontiers of AD research, these findings and updates could be worthy of further attention.
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22
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Crespo Pimentel B, Sedlacik J, Schröder J, Heinze M, Østergaard L, Fiehler J, Gerloff C, Thomalla G, Cheng B. Comprehensive Evaluation of Cerebral Hemodynamics and Oxygen Metabolism in Revascularization of Asymptomatic High-Grade Carotid Stenosis. Clin Neuroradiol 2021; 32:163-173. [PMID: 34487195 PMCID: PMC8894147 DOI: 10.1007/s00062-021-01077-3] [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: 11/08/2020] [Accepted: 07/22/2021] [Indexed: 11/25/2022]
Abstract
Introduction Revascularization procedures in carotid artery stenosis have shown a positive effect in the restoration of cerebral oxygen metabolism as assessed by T2’ (T2 prime) imaging as well as capillary homeostasis by measurement of capillary transit time heterogeneity (CTH); however, data in patients with asymptomatic carotid stenosis without manifest brain lesions are scarce. Patients and Methods The effect of revascularization on the hemodynamic profile and capillary homeostasis was evaluated in 13 patients with asymptomatic high-grade carotid stenosis without ischemic brain lesions using dynamic susceptibility contrast perfusion imaging and oxygenation-sensitive T2’ mapping before and 6–8 weeks after revascularization by endarterectomy or stenting. The cognitive performance at both timepoints was further assessed. Results Perfusion impairment at baseline was accompanied by an increased CTH (p = 0.008) in areas with a time to peak delay ≥ 2 s in the affected hemisphere compared to contralateral regions. Carotid intervention improved the overall moderate hemodynamic impairment at baseline by leading to an increase in normalized cerebral blood flow (p = 0.017) and a decrease in mean transit time (p = 0.027), oxygen extraction capacity (OEC) (p = 0.033) and CTH (p = 0.048). The T2’ values remained unchanged. Conclusion This study presents novel evidence of a state of altered microvascular function in patients with high-grade carotid artery stenosis in the absence of ischemic brain lesions, which shows sustained normalization after revascularization procedures. Supplementary Information The online version of this article (10.1007/s00062-021-01077-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Jan Sedlacik
- Centre for the Developing Brain & Biomedical Engineering Department, School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK
| | - Julian Schröder
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Marlene Heinze
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Fiehler
- Department of Neuroradiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Gerloff
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Götz Thomalla
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Bastian Cheng
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
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23
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Wu YC, Sonninen TM, Peltonen S, Koistinaho J, Lehtonen Š. Blood-Brain Barrier and Neurodegenerative Diseases-Modeling with iPSC-Derived Brain Cells. Int J Mol Sci 2021; 22:7710. [PMID: 34299328 PMCID: PMC8307585 DOI: 10.3390/ijms22147710] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022] Open
Abstract
The blood-brain barrier (BBB) regulates the delivery of oxygen and important nutrients to the brain through active and passive transport and prevents neurotoxins from entering the brain. It also has a clearance function and removes carbon dioxide and toxic metabolites from the central nervous system (CNS). Several drugs are unable to cross the BBB and enter the CNS, adding complexity to drug screens targeting brain disorders. A well-functioning BBB is essential for maintaining healthy brain tissue, and a malfunction of the BBB, linked to its permeability, results in toxins and immune cells entering the CNS. This impairment is associated with a variety of neurological diseases, including Alzheimer's disease and Parkinson's disease. Here, we summarize current knowledge about the BBB in neurodegenerative diseases. Furthermore, we focus on recent progress of using human-induced pluripotent stem cell (iPSC)-derived models to study the BBB. We review the potential of novel stem cell-based platforms in modeling the BBB and address advances and key challenges of using stem cell technology in modeling the human BBB. Finally, we highlight future directions in this area.
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Affiliation(s)
- Ying-Chieh Wu
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
| | - Tuuli-Maria Sonninen
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
| | - Sanni Peltonen
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
| | - Jari Koistinaho
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Šárka Lehtonen
- Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland; (Y.-C.W.); (T.-M.S.); (S.P.); (J.K.)
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
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24
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Jiang H, Wang J, Levin BE, Baumel BS, Camargo CJ, Signorile JF, Rundek T. Retinal Microvascular Alterations as the Biomarkers for Alzheimer Disease: Are We There Yet? J Neuroophthalmol 2021; 41:251-260. [PMID: 33136677 PMCID: PMC8079547 DOI: 10.1097/wno.0000000000001140] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Alzheimer disease (AD) is a heterogeneous and multifactorial disorder with an insidious onset and slowly progressive disease course. To date, there are no effective treatments, but biomarkers for early diagnosis and monitoring of disease progression offer a promising first step in developing and testing potential interventions. Cerebral vascular imaging biomarkers to assess the contributions of vascular dysfunction to AD are strongly recommended to be integrated into the current amyloid-β (Aβ) [A], tau [T], and neurodegeneration [(N)]-the "AT(N)" biomarker system for clinical research. However, the methodology is expensive and often requires invasive procedures to document cerebral vascular dysfunction. The retina has been used as a surrogate to study cerebral vascular changes. There is growing interest in the identification of retinal microvascular changes as a safe, easily accessible, low cost, and time-efficient approach to enhancing our understanding of the vascular pathogenesis associated with AD. EVIDENCE ACQUISITION A systemic review of the literature was performed regarding retinal vascular changes in AD and its prodromal stages, focusing on functional and structural changes of large retinal vessels (vessels visible on fundus photographs) and microvasculature (precapillary arterioles, capillary, and postcapillary venules) that are invisible on fundus photographs. RESULTS Static and dynamic retinal microvascular alterations such as retinal arterial wall motion, blood flow rate, and microvascular network density were reported in AD, mild cognitive impairment, and even in the preclinical stages of the disease. The data are somewhat controversial and inconsistent among the articles reviewed and were obtained based on cross-sectional studies that used different patient cohorts, equipment, techniques, and analysis methods. CONCLUSIONS Retinal microvascular alterations exist across the AD spectrum. Further large scale, within-subject longitudinal studies using standardized imaging and analytical methods may advance our knowledge concerning vascular contributions to the pathogenesis of AD.
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Affiliation(s)
- Hong Jiang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bonnie E. Levin
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bernard S. Baumel
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Christian J. Camargo
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | - Tania Rundek
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
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25
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Tubi MA, Kothapalli D, Hapenney M, Feingold FW, Mack WJ, King KS, Thompson PM, Braskie MN. Regional relationships between CSF VEGF levels and Alzheimer's disease brain biomarkers and cognition. Neurobiol Aging 2021; 105:241-251. [PMID: 34126466 DOI: 10.1016/j.neurobiolaging.2021.04.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/22/2021] [Accepted: 04/24/2021] [Indexed: 01/17/2023]
Abstract
Vascular endothelial growth factor (VEGF) is a complex signaling protein that supports vascular and neuronal function. Alzheimer's disease (AD) -neuropathological hallmarks interfere with VEGF signaling and modify previously detected positive associations between cerebral spinal fluid (CSF) VEGF and cognition and hippocampal volume. However, it remains unknown 1) whether regional relationships between VEGF and glucose metabolism and cortical thinning exist, and 2) whether AD-neuropathological hallmarks (CSF Aβ, t-tau, p-tau) also modify these relationships. We addressed this in 310 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants (92 cognitively normal, 149 mild cognitive impairment, 69 AD; 215 CSF Aβ+, 95 CSF Aβ-) with regional cortical thickness and cognition measurements and 158 participants with FDG-PET. In Aβ + participants (CSF Aβ42 ≤ 192 pg/mL), higher CSF VEGF levels were associated with greater FDG-PET signal in the inferior parietal, and middle and inferior temporal cortices. Abnormal CSF amyloid and tau levels strengthened the positive association between VEGF and regional FDG-PET indices. VEGF also had both direct associations with semantic memory, as well as indirect associations mediated by regional FDG-PET signal to cognition.
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Affiliation(s)
- Meral A Tubi
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Deydeep Kothapalli
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Matthew Hapenney
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Franklin W Feingold
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA; Stanford University, Stanford, CA 94305
| | - Wendy J Mack
- Division of Biostatistics, Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kevin S King
- Huntington Medical Research Institutes, Imaging Division, Pasadena, CA, 91105 USA
| | - Paul M Thompson
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA
| | - Meredith N Braskie
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, USA.
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26
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Jordan LC, DeBaun MR, Donahue MJ. Advances in neuroimaging to improve care in sickle cell disease. Lancet Neurol 2021; 20:398-408. [PMID: 33894194 DOI: 10.1016/s1474-4422(20)30490-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/26/2022]
Abstract
Sickle cell disease is associated with progressive and increased neurological morbidity throughout the lifespan. In people with sickle cell anaemia (the most common and severe type of sickle cell disease), silent cerebral infarcts are found in more than a third of adolescents by age 18 years and roughly half of young adults by age 30 years, many of whom have cognitive impairment despite having few or no conventional stroke risk factors. Common anatomical neuroimaging in individuals with sickle disease can assess structural brain injury, such as stroke and silent cerebral infarcts; however, emerging advanced neuroimaging methods can provide novel insights into the pathophysiology of sickle cell disease, including insights into the cerebral haemodynamic and metabolic contributors of neurological injury. Advanced neuroimaging methods, particularly methods that report on aberrant cerebral blood flow and oxygen delivery, have potential for triaging patients for appropriate disease-modifying or curative therapies before they have irreversible neurological injury, and for confirming the benefit of new therapies on brain health in clinical trials.
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Affiliation(s)
- Lori C Jordan
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Michael R DeBaun
- Department of Pediatrics, Vanderbilt-Meharry Center of Excellence in Sickle Cell Disease, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J Donahue
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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27
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Li N, Chen K, Bai J, Geng Z, Tang Y, Hou Y, Fan F, Ai X, Hu Y, Meng X, Wang X, Zhang Y. Tibetan medicine Duoxuekang ameliorates hypobaric hypoxia-induced brain injury in mice by restoration of cerebrovascular function. JOURNAL OF ETHNOPHARMACOLOGY 2021; 270:113629. [PMID: 33246120 DOI: 10.1016/j.jep.2020.113629] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 11/01/2020] [Accepted: 11/23/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Duoxuekang (DXK, ཁྲག་འཕེལ་བདེ་བྱེད།) is a clinical experience prescription of CuoRu-Cailang, a famous Tibetan medicine master, which has effective advantages in the treatment of hypobaric hypoxia (HH)-induced brain injury. However, its underlying mechanisms remain unclear. AIM OF THE STUDY The present study was designed to investigate the effects of DXK on cerebrovascular function of HH-induced brain injury in mice. MATERIALS AND METHODS DSC-MR imaging was used to evaluate the effect of DXK on the brain blood perfusion of patients with hypoxic brain injury. HPLC analysis was used to detect the content of salidroside, gallic acid, tyrosol, corilagin, ellagic acid, isorhamnetin, quercetin and gingerol in DXK. The model of HH-induced brain injury in mice was established by an animal hypobaric and hypoxic chamber. The BABL/c mice were randomly divided into six groups: control group, model group, Hongjingtian oral liquid group (HOL, 3.3 ml/kg) and DXK groups (0.9, 1.8 and 3.6 g/kg). All mice (except the control group) were intragastrically administrated for a continuous 7 days and put into the animal hypobaric and hypoxic chamber after the last intragastric administration. Hematoxylin-eosin staining was employed to evaluate the pathological changes of brain tissue. Masson and Weigert stainings were used to detect the content of collagen fibers and elastic fibers of brain, respectively. Routine blood test and biochemical kits were used to analyze hematological parameters and oxidative stress indices. Immunofluorescence staining was applied to detect the protein levels of VEGF, CD31/vWF and α-SMA. RESULTS The results of DSC-MR imaging confirmed that DXK can increased CBV in the left temporal lobe while decreased MTT in the right frontal lobe, right temporal lobe and right occipital lobe of the brain. DXK contains salidroside, gallic acid, tyrosol, corilagin, ellagic acid, isorhamnetin, quercetin and gingerol. Compared with the model group, DXK can ameliorate the atrophy and deformation, and increase the number of pyramidal neurons in hippocampal CA3 area and cortical neurocytes. Masson and Weigert stainings results revealed that DXK can significantly increase the content of collagen fibers and elastic fibers in brain. Routine blood test results demonstrated that DXK can dramatically decrease the levels of WBC, MCH and MCHC, while increase RBC, HGB, HCT, MCV and PLT in the blood samples. Biochemical results revealed that DXK can markedly increase SOD, CAT and GSH activities, while decrease MDA activity. Immunofluorescence revealed that DXK can notably increase the protein levels of VEGF, CD31/vWF and α-SMA. CONCLUSIONS In conclusion, this study proved that DXK can ameliorate HH-induced brain injury by improving brain blood perfusion, increasing the number of collagen and elastic fibers and inhibiting oxidative stress injury. The underlying mechanisms may be involved in maintaining the integrity of cerebrovascular endothelial cells and vascular function. However, further in vivo and in vitro investigations are still needed to elucidate the mechanisms of DXK on regulating cerebral blood vessels.
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Affiliation(s)
- Ning Li
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Ke Chen
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jinrong Bai
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Zangjia Geng
- School of Pharmacy, Southwest Minzu University, Chengdu, 610041, China
| | - Yan Tang
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Ya Hou
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Fangfang Fan
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xiaopeng Ai
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Yao Hu
- Interdisciplinary Laboratory of Exercise and Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, Sichuan, China
| | - Xianli Meng
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| | - Xiaobo Wang
- Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| | - Yi Zhang
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; NMPA Key Laboratory for Quality Evaluation of Traditional Chinese Medicine (Traditional Chinese Patent Medicine), Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
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28
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Eskildsen SF, Iranzo A, Stokholm MG, Stær K, Østergaard K, Serradell M, Otto M, Svendsen KB, Garrido A, Vilas D, Borghammer P, Santamaria J, Møller A, Gaig C, Brooks DJ, Tolosa E, Østergaard L, Pavese N. Impaired cerebral microcirculation in isolated REM sleep behaviour disorder. Brain 2021; 144:1498-1508. [PMID: 33880533 DOI: 10.1093/brain/awab054] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/19/2020] [Accepted: 12/09/2020] [Indexed: 01/18/2023] Open
Abstract
During the prodromal period of Parkinson's disease and other α-synucleinopathy-related parkinsonisms, neurodegeneration is thought to progressively affect deep brain nuclei, such as the locus coeruleus, caudal raphe nucleus, substantia nigra, and the forebrain nucleus basalis of Meynert. Besides their involvement in the regulation of mood, sleep, behaviour, and memory functions, these nuclei also innervate parenchymal arterioles and capillaries throughout the cortex, possibly to ensure that oxygen supplies are adjusted according to the needs of neural activity. The aim of this study was to examine whether patients with isolated REM sleep behaviour disorder, a parasomnia considered to be a prodromal phenotype of α-synucleinopathies, reveal microvascular flow disturbances consistent with disrupted central blood flow control. We applied dynamic susceptibility contrast MRI to characterize the microscopic distribution of cerebral blood flow in the cortex of 20 polysomnographic-confirmed patients with isolated REM sleep behaviour disorder (17 males, age range: 54-77 years) and 25 healthy matched controls (25 males, age range: 58-76 years). Patients and controls were cognitively tested by Montreal Cognitive Assessment and Mini Mental State Examination. Results revealed profound hypoperfusion and microvascular flow disturbances throughout the cortex in patients compared to controls. In patients, the microvascular flow disturbances were seen in cortical areas associated with language comprehension, visual processing and recognition and were associated with impaired cognitive performance. We conclude that cortical blood flow abnormalities, possibly related to impaired neurogenic control, are present in patients with isolated REM sleep behaviour disorder and associated with cognitive dysfunction. We hypothesize that pharmacological restoration of perivascular neurotransmitter levels could help maintain cognitive function in patients with this prodromal phenotype of parkinsonism.
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Affiliation(s)
- Simon F Eskildsen
- Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Alex Iranzo
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Morten G Stokholm
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Kristian Stær
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Karen Østergaard
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Mónica Serradell
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Marit Otto
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Alicia Garrido
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Dolores Vilas
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Per Borghammer
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Joan Santamaria
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Arne Møller
- Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Carles Gaig
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - David J Brooks
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark.,Translational and Clinical Research Institute, Newcastle University, England, UK
| | - Eduardo Tolosa
- Department of Neurology, Hospital Clínic de Barcelona, Barcelona, Spain.,Parkinson disease and Movement Disorders Unit, Neurology Service, Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Neuroradiology Research Unit, Department of Radiology, Aarhus University Hospital, Denmark
| | - Nicola Pavese
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark.,Translational and Clinical Research Institute, Newcastle University, England, UK
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Wang NY, Li JN, Liu WL, Huang Q, Li WX, Tan YH, Liu F, Song ZH, Wang MY, Xie N, Mao RR, Gan P, Ding YQ, Zhang Z, Shan BC, Chen LD, Zhou QX, Xu L. Ferulic Acid Ameliorates Alzheimer's Disease-like Pathology and Repairs Cognitive Decline by Preventing Capillary Hypofunction in APP/PS1 Mice. Neurotherapeutics 2021; 18:1064-1080. [PMID: 33786807 PMCID: PMC8423929 DOI: 10.1007/s13311-021-01024-7] [Citation(s) in RCA: 25] [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] [Accepted: 02/04/2021] [Indexed: 12/14/2022] Open
Abstract
Brain capillaries are crucial for cognitive functions by supplying oxygen and other nutrients to and removing metabolic wastes from the brain. Recent studies have demonstrated that constriction of brain capillaries is triggered by beta-amyloid (Aβ) oligomers via endothelin-1 (ET1)-mediated action on the ET1 receptor A (ETRA), potentially exacerbating Aβ plaque deposition, the primary pathophysiology of Alzheimer's disease (AD). However, direct evidence is still lacking whether changes in brain capillaries are causally involved in the pathophysiology of AD. Using APP/PS1 mouse model of AD (AD mice) relative to age-matched negative littermates, we identified that reductions of density and diameter of hippocampal capillaries occurred from 4 to 7 months old while Aβ plaque deposition and spatial memory deficit developed at 7 months old. Notably, the injection of ET1 into the hippocampus induced early Aβ plaque deposition at 5 months old in AD mice. Conversely, treatment of ferulic acid against the ETRA to counteract the ET1-mediated vasoconstriction for 30 days prevented reductions of density and diameter of hippocampal capillaries as well as ameliorated Aβ plaque deposition and spatial memory deficit at 7 months old in AD mice. Thus, these data suggest that reductions of density and diameter of hippocampal capillaries are crucial for initiating Aβ plaque deposition and spatial memory deficit at the early stages, implicating the development of new therapies for halting or curing memory decline in AD.
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Affiliation(s)
- Ni-Ya Wang
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China
| | - Jin-Nan Li
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China
| | - Wei-Lin Liu
- The Academy of Rehabilitation Industry, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Qi Huang
- Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, the Chinese Academy of Sciences, Beijing, 100049, China
| | - Wen-Xing Li
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China
| | - Ya-Hong Tan
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China
| | - Fang Liu
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China
| | - Zi-Hua Song
- CAS Key Laboratory of Brain Function and Disease, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230027, China
| | - Meng-Yue Wang
- State Key Laboratory of Innovative Natural Drugs and Traditional Chinese Medicine Injections, Qingfeng Pharmaceutical Corporations, Ganzhou, 341000, China
| | - Ning Xie
- State Key Laboratory of Innovative Natural Drugs and Traditional Chinese Medicine Injections, Qingfeng Pharmaceutical Corporations, Ganzhou, 341000, China
| | - Rong-Rong Mao
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming Medical University, Kunming, 650500, China
| | - Ping Gan
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China
- Kunming Medical University, Kunming, 650500, China
| | - Yu-Qiang Ding
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Centre for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Zhi Zhang
- CAS Key Laboratory of Brain Function and Disease, Hefei National Laboratory for Physical Sciences At the Microscale, University of Science and Technology of China, Hefei, 230027, China
| | - Bao-Ci Shan
- Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, the Chinese Academy of Sciences, Beijing, 100049, China.
| | - Li-Dian Chen
- The Academy of Rehabilitation Industry, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China.
| | - Qi-Xin Zhou
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China.
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China.
| | - Lin Xu
- CAS Key Laboratory of Animal Models and Human Disease Mechanisms, and KIZ-SU Joint Laboratory of Animal Model and Drug Development, and Laboratory of Learning and Memory, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, 650223, China.
- Kunming College of Life Sciences, University of the Chinese Academy of Sciences, Kunming, 650223, China.
- Mental Health Institute, the Second Xiangya Hospital of Central South University, Changsha, 410008, China.
- CAS Centre for Excellence in Brain Science and Intelligent Technology, Shanghai, 200031, China.
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30
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Quantitative assessment of retinal thickness and vessel density using optical coherence tomography angiography in patients with Alzheimer's disease and glaucoma. PLoS One 2021; 16:e0248284. [PMID: 33739997 PMCID: PMC7978346 DOI: 10.1371/journal.pone.0248284] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Purpose Assessment and a direct comparison of retinal vessel density with the thickness of inner retinal layer (IRL) and outer retinal layer (ORL) in the same regions of the macula in subjects with Alzheimer’s disease (AD) and primary open-angle glaucoma (POAG). Methods We analyzed data from 48 eyes of healthy control (HC) participants, 71 eyes with POAG, and 49 eyes of AD patients. Ophthalmic examination included optical coherence tomography (OCT) imaging to measure IRL and ORL thickness and OCT angiography (OCTA) in the same region for the imaging of vessel density in the superficial vascular plexus (SVP) and deep vascular plexus (DVP) of the retina. A direct comparison of vessel density and retinal layers thickness, which different dynamic ranges, was obtained by normalizing values as percentage losses. Results Patients with AD presented significantly greater losses of vascular density in the DVP and ORL thickness compared to POAG (p <0.001), but percentage losses of vessel density in SVP and IRL thickness were considerable in POAG compared to AD eyes (p<0.001). Positive associations among presence of AD were observed primarily in outer retina where a 1% decrease of ORL thickness was associated with about 24–29% increase in odds of the presence of AD. According to OCTA measurements, a 1% decrease of vessel density in DVP was positively associated with a 4–9% increase in odds of the presence of AD. In POAG positive associations among presence of disease were observed only in inner retina where 1% loss of IRL thickness and a 1% loss of vessel density in the SVP were positively associated with a 13–23% increase in risk of presence of the disease. Conclusions Analysis of ORL thickness and vessel density in DVP could potentially improve diagnostic capabilities and may provide a valuable approach for predicting of AD.
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Trujillo P, Roman OC, Hay KR, Juttukonda MR, Yan Y, Kang H, Paranjape SY, Garland EM, Shibao CA, Biaggioni I, Donahue MJ, Claassen DO. Elevated cerebral blood flow in patients with pure autonomic failure. Clin Auton Res 2021; 31:405-414. [PMID: 33677714 DOI: 10.1007/s10286-021-00792-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 02/24/2021] [Indexed: 12/19/2022]
Abstract
PURPOSE Pure autonomic failure (PAF) results from an impaired peripheral autonomic nervous system, and clinical symptoms present with orthostatic hypotension. While the impact on cardiovascular indices of orthostatic intolerance are well-characterized, more limited information is available regarding cerebral hemodynamic dysfunction in PAF. The objective of this study was to test the hypothesis that cerebral blood flow (CBF) is reduced in PAF, and to quantify the relationship between CBF and clinical indicators of disease severity, including peripheral supine arterial blood pressure. METHODS Participants with PAF (n = 17) and age- and sex-matched normotensive healthy controls (n = 17) were examined using established clinical rating scales, cardiovascular autonomic function tests, and 3T MRI measurements of CBF. CBF-weighted images were also used to determine the prevalence of venous hyperintensities from the major dural sinuses as evidence of abnormal capillary flow. Nonparametric tests and general linear models were used to evaluate differences and correlations between study variables. RESULTS Gray matter CBF was higher in PAF (51.1 ± 13.4 mL/100 g/min) compared to controls (42.9 ± 6.5 mL/100 g/min, p = 0.007). Venous hyperintensities were more prevalent in PAF relative to controls, and the presence and degree of venous hyperintensities was associated with higher mean CBF (p = 0.027). In PAF participants, CBF and supine systolic blood pressure were inversely related (Spearman's rho = -0.545, p = 0.024). CONCLUSIONS Findings suggest that PAF patients may exhibit elevated CBF and provide evidence that this condition exerts a hemodynamic impact in the central nervous system.
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Affiliation(s)
- Paula Trujillo
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Ave South A-0118, Nashville, TN, 37232, USA
| | - Olivia C Roman
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kaitlyn R Hay
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Ave South A-0118, Nashville, TN, 37232, USA
| | - Meher R Juttukonda
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Yan Yan
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Sachin Y Paranjape
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Emily M Garland
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Cyndya A Shibao
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Italo Biaggioni
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J Donahue
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Ave South A-0118, Nashville, TN, 37232, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Daniel O Claassen
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Ave South A-0118, Nashville, TN, 37232, USA.
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32
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Juttukonda MR, Donahue MJ, Waddle SL, Davis LT, Lee CA, Patel NJ, Pruthi S, Kassim AA, Jordan LC. Reduced oxygen extraction efficiency in sickle cell anemia patients with evidence of cerebral capillary shunting. J Cereb Blood Flow Metab 2021; 41:546-560. [PMID: 32281458 PMCID: PMC7922746 DOI: 10.1177/0271678x20913123] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Arterial spin labeling (ASL) magnetic resonance imaging (MRI) utilizes arterial blood water as an endogenous contrast agent to provide a quantitative measure of cerebral blood flow (CBF). Recently, hyperintense signal within dural venous sinuses in ASL images of sickle cell anemia (SCA) patients has been shown to be consistent with elevated flow velocities and may indicate capillary shunting and reduced oxygen extraction. Here, we performed oxygen extraction fraction (OEF) and CBF measurements in adults (cumulative n = 114) with (n = 69) and without (n = 45) SCA to test the hypothesis that hyperintense venous ASL signal is associated with reduced OEF. Higher categorical scores of shunting on ASL MRI were associated with lower OEF in participants with silent cerebral infarcts or white matter hyperintensities (p = 0.003), but not in those without lesions (p = 0.551). These findings indicate that venous hyperintense signal in ASL images in SCA patients may represent a marker of capillary-level disturbances in oxygen exchange efficiency and small vessel pathology.
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Affiliation(s)
- Meher R Juttukonda
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J Donahue
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Spencer L Waddle
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Larry T Davis
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Chelsea A Lee
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Niral J Patel
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sumit Pruthi
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Adetola A Kassim
- Department of Medicine, Division of Hematology-Oncology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lori C Jordan
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
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33
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Østergaard L. SARS CoV-2 related microvascular damage and symptoms during and after COVID-19: Consequences of capillary transit-time changes, tissue hypoxia and inflammation. Physiol Rep 2021; 9:e14726. [PMID: 33523608 PMCID: PMC7849453 DOI: 10.14814/phy2.14726] [Citation(s) in RCA: 149] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/15/2022] Open
Abstract
Corona virus disease 2019 (COVID-19) causes symptoms from multiple organs after infection by severe acute respiratory syndrome corona virus 2 (SARS CoV-2). They range from early, low blood oxygen levels (hypoxemia) without breathlessness ("silent hypoxia"), delirium, rashes, and loss of smell (anosmia), to persisting chest pain, muscle weakness and -pain, fatigue, confusion, memory problems and difficulty to concentrate ("brain fog"), mood changes, and unexpected onset of hypertension or diabetes. SARS CoV-2 affects the microcirculation, causing endothelial cell swelling and damage (endotheliitis), microscopic blood clots (microthrombosis), capillary congestion, and damage to pericytes that are integral to capillary integrity and barrier function, tissue repair (angiogenesis), and scar formation. Similar to other instances of critical illness, COVID-19 is also associated with elevated cytokine levels in the systemic circulation. This review examines how capillary damage and inflammation may contribute to these acute and persisting COVID-19 symptoms by interfering with blood and tissue oxygenation and with brain function. Undetectable by current diagnostic methods, capillary flow disturbances limit oxygen diffusion exchange in lungs and tissue and may therefore cause hypoxemia and tissue hypoxia. The review analyzes the combined effects of COVID-19-related capillary damage, pre-existing microvascular changes, and upstream vascular tone on tissue oxygenation in key organs. It identifies a vicious cycle, as infection- and hypoxia-related inflammation cause capillary function to deteriorate, which in turn accelerates hypoxia-related inflammation and tissue damage. Finally, the review addresses the effects of low oxygen and high cytokine levels in brain tissue on neurotransmitter synthesis and mood. Methods to assess capillary functions in human organs and therapeutic means to protect capillary functions and stimulate capillary bed repair may prove important for the individualized management of COVID-19 patients and targeted rehabilitation strategies.
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Affiliation(s)
- Leif Østergaard
- Neuroradiology Research UnitSection of NeuroradiologyDepartment of RadiologyAarhus University HospitalAarhusDenmark
- Center of Functionally Integrative NeuroscienceDepartment of Clinical MedicineAarhus UniversityAarhusDenmark
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Steinman J, Sun HS, Feng ZP. Microvascular Alterations in Alzheimer's Disease. Front Cell Neurosci 2021; 14:618986. [PMID: 33536876 PMCID: PMC7849053 DOI: 10.3389/fncel.2020.618986] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder associated with continual decline in cognition and ability to perform routine functions such as remembering familiar places or understanding speech. For decades, amyloid beta (Aβ) was viewed as the driver of AD, triggering neurodegenerative processes such as inflammation and formation of neurofibrillary tangles (NFTs). This approach has not yielded therapeutics that cure the disease or significant improvements in long-term cognition through removal of plaques and Aβ oligomers. Some researchers propose alternate mechanisms that drive AD or act in conjunction with amyloid to promote neurodegeneration. This review summarizes the status of AD research and examines research directions including and beyond Aβ, such as tau, inflammation, and protein clearance mechanisms. The effect of aging on microvasculature is highlighted, including its contribution to reduced blood flow that impairs cognition. Microvascular alterations observed in AD are outlined, emphasizing imaging studies of capillary malfunction. The review concludes with a discussion of two therapies to protect tissue without directly targeting Aβ for removal: (1) administration of growth factors to promote vascular recovery in AD; (2) inhibiting activity of a calcium-permeable ion channels to reduce microglial activation and restore cerebral vascular function.
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Affiliation(s)
- Joe Steinman
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Hong-Shuo Sun
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Zhong-Ping Feng
- Department of Physiology, University of Toronto, Toronto, ON, Canada
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35
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Korte N, Nortley R, Attwell D. Cerebral blood flow decrease as an early pathological mechanism in Alzheimer's disease. Acta Neuropathol 2020; 140:793-810. [PMID: 32865691 PMCID: PMC7666276 DOI: 10.1007/s00401-020-02215-w] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/15/2020] [Accepted: 08/15/2020] [Indexed: 02/08/2023]
Abstract
Therapies targeting late events in Alzheimer's disease (AD), including aggregation of amyloid beta (Aβ) and hyperphosphorylated tau, have largely failed, probably because they are given after significant neuronal damage has occurred. Biomarkers suggest that the earliest event in AD is a decrease of cerebral blood flow (CBF). This is caused by constriction of capillaries by contractile pericytes, probably evoked by oligomeric Aβ. CBF is also reduced by neutrophil trapping in capillaries and clot formation, perhaps secondary to the capillary constriction. The fall in CBF potentiates neurodegeneration by upregulating the BACE1 enzyme that makes Aβ and by promoting tau hyperphosphorylation. Surprisingly, therefore, CBF reduction may play a crucial role in driving cognitive decline by initiating the amyloid cascade itself, or being caused by and amplifying Aβ production. Here, we review developments in this area that are neglected in current approaches to AD, with the aim of promoting novel mechanism-based therapeutic approaches.
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Affiliation(s)
- Nils Korte
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Ross Nortley
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
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36
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Schager B, Brown CE. Susceptibility to capillary plugging can predict brain region specific vessel loss with aging. J Cereb Blood Flow Metab 2020; 40:2475-2490. [PMID: 31903837 PMCID: PMC7820682 DOI: 10.1177/0271678x19895245] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/28/2019] [Accepted: 11/19/2019] [Indexed: 12/13/2022]
Abstract
Vessel loss in the aging brain is commonly reported, yet important questions remain concerning whether there are regional vulnerabilities and what mechanisms could account for these regional differences, if they exist. Here we imaged and quantified vessel length, tortuosity and width in 15 brain regions in young adult and aged mice. Our data indicate that vessel loss was most pronounced in white matter followed by cortical, then subcortical grey matter regions, while some regions (visual cortex, amygdala, thalamus) showed no decline with aging. Regions supplied by the anterior cerebral artery were more vulnerable to loss than those supplied by middle or posterior cerebral arteries. Vessel width and tortuosity generally increased with age but neither reliably predicted regional vessel loss. Since capillaries are naturally prone to plugging and prolonged obstructions often lead to vessel pruning, we hypothesized that regional susceptibilities to plugging could help predict vessel loss. By mapping the distribution of microsphere-induced capillary obstructions, we discovered that regions with a higher density of persistent obstructions were more likely to show vessel loss with aging and vice versa. These findings indicate that age-related vessel loss is region specific and can be explained, at least partially, by regional susceptibilities to capillary plugging.
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Affiliation(s)
- Ben Schager
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Craig E Brown
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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37
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Salminen A. Hypoperfusion is a potential inducer of immunosuppressive network in Alzheimer's disease. Neurochem Int 2020; 142:104919. [PMID: 33242538 DOI: 10.1016/j.neuint.2020.104919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 10/12/2020] [Accepted: 11/19/2020] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease which causes a non-reversible cognitive impairment and dementia. The primary cause of late-onset AD remains unknown although its pathology was discovered over a century ago. Recently, the vascular hypothesis of AD has received backing from evidence emerging from neuroimaging studies which have revealed the presence of a significant hypoperfusion in the brain regions vulnerable to AD pathology. In fact, hypoxia can explain many of the pathological changes evident in AD pathology, e.g. the deposition of β-amyloid plaques and chronic low-grade inflammation. Hypoxia-inducible factor-1α (HIF-1α) stimulates inflammatory responses and modulates both innate and adaptive immunity. It is known that hypoxia-induced inflammation evokes compensatory anti-inflammatory response involving tissue-resident microglia/macrophages and infiltrated immune cells. Hypoxia/HIF-1α induce immunosuppression by (i) increasing the expression of immunosuppressive genes, (ii) stimulating adenosinergic signaling, (iii) enhancing aerobic glycolysis, i.e. lactate production, and (iv) augmenting the secretion of immunosuppressive exosomes. Interestingly, it seems that these common mechanisms are also involved in the pathogenesis of AD. In AD pathology, an enhanced immunosuppression appears, e.g. as a shift in microglia/macrophage phenotypes towards the anti-inflammatory M2 phenotype and an increase in the numbers of regulatory T cells (Treg). The augmented anti-inflammatory capacity promotes the resolution of acute inflammation but persistent inflammation has crucial effects not only on immune cells but also harmful responses to the homeostasis of AD brain. I will examine in detail the mechanisms of the hypoperfusion/hypoxia-induced immunosuppressive state in general and especially, in its association with AD pathogenesis. These immunological observations support the vascular hypothesis of AD pathology.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
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38
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Lee JS, Lee H, Park S, Choe Y, Park YH, Cheon BK, Hahn A, Ossenkoppele R, Kim HJ, Kim S, Yoo H, Jang H, Cho SH, Kim SJ, Kim JP, Jung YH, Park KC, DeCarli C, Weiner MW, Na DL, Seo SW. Association between APOE ε2 and Aβ burden in patients with Alzheimer- and vascular-type cognitive impairment. Neurology 2020; 95:e2354-e2365. [PMID: 32928967 DOI: 10.1212/wnl.0000000000010811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 06/03/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate the association between APOE genotype and β-amyloid (Aβ) burden, as measured by PET in patients with subcortical vascular cognitive impairment (SVCI) and those with Alzheimer disease-related cognitive impairment (ADCI). METHODS This was a cross-sectional study of 310 patients with SVCI and 999 with ADCI. To evaluate the effects of APOE genotype or diagnostic group on Aβ positivity, we performed multivariate logistic regression analyses. Further distinctive underlying features of latent subgroups were examined by employing a latent class cluster analysis approach. RESULTS In comparison with ε3 homozygotes, in the ADCI group, ε2 carriers showed a lower frequency of Aβ positivity (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.23-0.79), while in the SVCI group, ε2 carriers showed a higher frequency of Aβ positivity (OR 2.26, 95% CI 1.02-5.01). In particular, we observed an interaction effect of ε2 carrier status and diagnostic group on Aβ positivity (OR 5.12, 95% CI 1.93-13.56), in that relative to ε3 homozygotes, there were more Aβ-positive ε2 carriers in the SVCI group than in the ADCI group. We also identified latent subgroups of Aβ-positive APOE ε2 carriers with SVCI and Aβ-positive APOE ε4 carriers with ADCI. CONCLUSIONS Our findings suggest that APOE ε2 is distinctly associated with Aβ deposition in patients with SVCI and those with ADCI. Our findings further suggest that there is a distinctive subgroup of Aβ-positive APOE ε2 carriers with SVCI among patients with cognitive impairment.
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Affiliation(s)
- Jin San Lee
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA.
| | - Hyejoo Lee
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA.
| | - Seongbeom Park
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Yeongsim Choe
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Yu Hyun Park
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Bo Kyoung Cheon
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Alice Hahn
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Rik Ossenkoppele
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Hee Jin Kim
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Seonwoo Kim
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Heejin Yoo
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Hyemin Jang
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Soo Hyun Cho
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Seung Joo Kim
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Jun Pyo Kim
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Young Hee Jung
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Key-Chung Park
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Charles DeCarli
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Michael W Weiner
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Duk L Na
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA
| | - Sang Won Seo
- From the Department of Neurology (J.S.L., H.L., S.P., Y.C., Y.H.P., B.K.C., A.H., H.J.K., H.J., J.P.K., D.L.N., S.W.S.), Samsung Alzheimer Research Center (H.J.K., H.J., J.P.K., D.L.N., S.W.S.), and Statistics and Data Center (S.K., H.Y.), Samsung Medical Center; Department of Intelligent Precision Healthcare Convergence (S.W.S.), Sungkyunkwan University School of Medicine; Department of Health Sciences and Technology (S.W.S.), SAIHST, Sungkyunkwan University; Department of Neurology (J.S.L., K.-C.P.), Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea; Department of Neurology and Alzheimer Center (R.O.), Neuroscience Campus Amsterdam, VU University Medical Center, the Netherlands; Department of Neurology (S.H.C.), Chonnam National University Medical School, Gwangju; Department of Neurology (S.J.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon; Department of Neurology (Y.H.J.), Myungji Hospital, Goyang, Korea; Department of Neurology and Center for Neuroscience (C.D.), University of California, Davis; Department of Medicine (M.W.W.), University of California; and Department of Veterans Affairs Medical Center (M.W.W.), Center for Imaging of Neurodegenerative Diseases, San Francisco, CA.
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Østergaard L. Blood flow, capillary transit times, and tissue oxygenation: the centennial of capillary recruitment. J Appl Physiol (1985) 2020; 129:1413-1421. [PMID: 33031017 DOI: 10.1152/japplphysiol.00537.2020] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The transport of oxygen between blood and tissue is limited by blood's capillary transit time, understood as the time available for diffusion exchange before blood returns to the heart. If all capillaries contribute equally to tissue oxygenation at all times, this physical limitation would render vasodilation and increased blood flow insufficient means to meet increased metabolic demands in the heart, muscle, and other organs. In 1920, Danish physiologist August Krogh was awarded the Nobel Prize in Physiology or Medicine for his mathematical and quantitative, experimental demonstration of a solution to this conceptual problem: capillary recruitment, the active opening of previously closed capillaries to meet metabolic demands. Today, capillary recruitment is still mentioned in textbooks. When we suspect symptoms might represent hypoxia of a vascular origin, however, we search for relevant, flow-limiting conditions in our patients and rarely ascribe hypoxia or hypoxemia to short capillary transit times. This review describes how natural changes in capillary transit-time heterogeneity (CTH) and capillary hematocrit (HCT) across open capillaries during blood flow increases can account for a match of oxygen availability to metabolic demands in normal tissue. CTH and HCT depend on a number of factors: on blood properties, including plasma viscosity, the number, size, and deformability of blood cells, and blood cell interactions with capillary endothelium; on anatomical factors including glycocalyx, endothelial cells, basement membrane, and pericytes that affect the capillary diameter; and on any external compression. The review describes how risk factor- and disease-related changes in CTH and HCT interfere with flow-metabolism coupling and tissue oxygenation and discusses whether such capillary dysfunction contributes to vascular disease pathology.
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Affiliation(s)
- Leif Østergaard
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Neuroradiology Research Unit, Section of Neuroradiology, Department of Radiology, Aarhus University Hospital, Aarhus, Denmark
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Poole DC, Pittman RN, Musch TI, Østergaard L. August Krogh's theory of muscle microvascular control and oxygen delivery: a paradigm shift based on new data. J Physiol 2020; 598:4473-4507. [PMID: 32918749 DOI: 10.1113/jp279223] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022] Open
Abstract
August Krogh twice won the prestigious international Steegen Prize, for nitrogen metabolism (1906) and overturning the concept of active transport of gases across the pulmonary epithelium (1910). Despite this, at the beginning of 1920, the consummate experimentalist was relatively unknown worldwide and even among his own University of Copenhagen faculty. But, in early 1919, he had submitted three papers to Dr Langley, then editor of The Journal of Physiology in England. These papers coalesced anatomical observations of skeletal muscle capillary numbers with O2 diffusion theory to propose a novel active role for capillaries that explained the prodigious increase in blood-muscle O2 flux from rest to exercise. Despite his own appraisal of the first two papers as "rather dull" to his friend, the eminent Cambridge respiratory physiologist, Joseph Barcroft, Krogh believed that the third one, dealing with O2 supply and capillary regulation, was"interesting". These papers, which won Krogh an unopposed Nobel Prize for Physiology or Medicine in 1920, form the foundation for this review. They single-handedly transformed the role of capillaries from passive conduit and exchange vessels, functioning at the mercy of their upstream arterioles, into independent contractile units that were predominantly closed at rest and opened actively during muscle contractions in a process he termed 'capillary recruitment'. Herein we examine Krogh's findings and some of the experimental difficulties he faced. In particular, the boundary conditions selected for his model (e.g. heavily anaesthetized animals, negligible intramyocyte O2 partial pressure, binary open-closed capillary function) have not withstood the test of time. Subsequently, we update the reader with intervening discoveries that underpin our current understanding of muscle microcirculatory control and place a retrospectroscope on Krogh's discoveries. The perspective is presented that the imprimatur of the Nobel Prize, in this instance, may have led scientists to discount compelling evidence. Much as he and Marie Krogh demonstrated that active transport of gases across the blood-gas barrier was unnecessary in the lung, capillaries in skeletal muscle do not open and close spontaneously or actively, nor is this necessary to account for the increase in blood-muscle O2 flux during exercise. Thus, a contemporary model of capillary function features most muscle capillaries supporting blood flow at rest, and, rather than capillaries actively vasodilating from rest to exercise, increased blood-myocyte O2 flux occurs predominantly via elevating red blood cell and plasma flux in already flowing capillaries. Krogh is lauded for his brilliance as an experimentalist and for raising scientific questions that led to fertile avenues of investigation, including the study of microvascular function.
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Affiliation(s)
- David C Poole
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University Manhattan, Manhattan, KS, 66506, USA
| | - Roland N Pittman
- Department of Physiology and Biophysics, Virginia Commonwealth University Richmond, Richmond, VA, 23298-0551, USA
| | - Timothy I Musch
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University Manhattan, Manhattan, KS, 66506, USA
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience, Aarhus University, Denmark
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Nielsen RB, Parbo P, Ismail R, Dalby R, Tietze A, Brændgaard H, Gottrup H, Brooks DJ, Østergaard L, Eskildsen SF. Impaired perfusion and capillary dysfunction in prodromal Alzheimer's disease. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12032. [PMID: 32490139 PMCID: PMC7241262 DOI: 10.1002/dad2.12032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Cardiovascular disease increases the risk of developing Alzheimer's disease (AD), and growing evidence suggests an involvement of cerebrovascular pathology in AD. Capillary dysfunction, a condition in which capillary flow disturbances rather than arterial blood supply limit brain oxygen extraction, could represent an overlooked vascular contributor to neurodegeneration. We examined whether cortical capillary transit-time heterogeneity (CTH), an index of capillary dysfunction, is elevated in amyloid-positive patients with mild cognitive impairment (prodromal AD [pAD]). METHODS We performed structural and perfusion weighted MRI in 22 pAD patients and 21 healthy controls. RESULTS We found hypoperfusion, reduced blood volume, and elevated CTH in the parietal and frontal cortices of pAD-patients compared to controls, while only the precuneus showed focal cortical atrophy. DISCUSSION We propose that microvascular flow disturbances antedate cortical atrophy and may limit local tissue oxygenation in pAD. We speculate that capillary dysfunction contributes to the development of neurodegeneration in AD.
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Affiliation(s)
- Rune B. Nielsen
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
| | - Peter Parbo
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
| | - Rola Ismail
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
| | - Rikke Dalby
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
- Department of NeuroradiologyAarhus University HospitalAarhusDenmark
| | - Anna Tietze
- Charité, UniversitätsmedizinInstitute of NeuroradiologyBerlinGermany
| | - Hans Brændgaard
- Dementia ClinicDepartment of NeurologyAarhus University HospitalAarhusDenmark
| | - Hanne Gottrup
- Dementia ClinicDepartment of NeurologyAarhus University HospitalAarhusDenmark
| | - David J. Brooks
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
- Division of NeuroscienceDepartment of MedicineImperial College LondonLondonUK
- Division of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Leif Østergaard
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
| | - Simon F. Eskildsen
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
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42
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Hashimoto Y, Campbell M. Tight junction modulation at the blood-brain barrier: Current and future perspectives. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183298. [PMID: 32353377 DOI: 10.1016/j.bbamem.2020.183298] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/09/2020] [Accepted: 03/28/2020] [Indexed: 12/14/2022]
Abstract
The blood-brain barrier (BBB) is the one of the most robust physical barriers in the body, comprised of tight junction (TJ) proteins in brain microvascular endothelial cells. The need for drugs to treat central nervous systems diseases is ever increasing, however the presence of the BBB significantly hampers the uptake of drugs into the brain. To overcome or circumvent the barrier, many kinds of techniques are being developed. Modulating the paracellular route by disruption of the TJ complex has been proposed as a potential drug delivery system to treat brain diseases, however, it has several limitations and is still in a developmental stage. However, recent significant advance in medical equipment /tools such as targeted ultra-sound technologies may resolve these limitations. In this review, we introduce recent advances in site- or molecular size-selective BBB disruption/modulation technologies and we include details on pharmacological inhibitory molecules against intercellular TJ proteins to modulate the BBB.
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Affiliation(s)
- Yosuke Hashimoto
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
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43
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Single-cell RNA sequencing identifies senescent cerebromicrovascular endothelial cells in the aged mouse brain. GeroScience 2020; 42:429-444. [PMID: 32236824 PMCID: PMC7205992 DOI: 10.1007/s11357-020-00177-1] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/01/2020] [Indexed: 01/21/2023] Open
Abstract
Age-related phenotypic changes of cerebromicrovascular endothelial cells lead to dysregulation of cerebral blood flow and blood-brain barrier disruption, promoting the pathogenesis of vascular cognitive impairment (VCI). In recent years, endothelial cell senescence has emerged as a potential mechanism contributing to microvascular pathologies opening the avenue to the therapeutic exploitation of senolytic drugs in preclinical studies. However, difficulties with the detection of senescent endothelial cells in wild type mouse models of aging hinder the assessment of the efficiency of senolytic treatments. To detect senescent endothelial cells in the aging mouse brain, we analyzed 4233 cells in fractions enriched for cerebromicrovascular endothelial cells and other cells associated with the neurovascular unit obtained from young (3-month-old) and aged (28-month-old) C57BL/6 mice. We define 13 transcriptomic cell types by deep, single-cell RNA sequencing. We match transcriptomic signatures of cellular senescence to endothelial cells identified on the basis of their gene expression profile. Our study demonstrates that with advanced aging, there is an increased ratio of senescent endothelial cells (~ 10%) in the mouse cerebral microcirculation. We propose that our single-cell RNA sequencing-based method can be adapted to study the effect of aging on senescence in various brain cell types as well as to evaluate the efficiency of various senolytic regimens in multiple tissues.
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44
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Hoshino T, Matsuzawa SI, Takahashi R. 6-Deoxyjacareubin, a natural compound preventing hypoxia-induced cell death, ameliorates neurodegeneration in a mouse model of familial amyotrophic lateral sclerosis. Neurosci Res 2020; 163:43-51. [PMID: 32145212 DOI: 10.1016/j.neures.2020.02.011] [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: 12/02/2019] [Revised: 02/04/2020] [Accepted: 02/25/2020] [Indexed: 10/24/2022]
Abstract
The central nervous system (CNS) uses a significant amount of oxygen for energy production. Decreased oxygen supply due to impaired blood supply critically damages the CNS. As chronic hypoxic conditions have diverse effects via the excessive production of reactive oxygen species, protection from hypoxic damage is important for cell survival. Recent studies have revealed that various markers of hypoxia are altered in age-related neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), indicating the involvement of hypoxia. However, therapeutic strategies targeting hypoxia-induced pathways in ALS have not been developed yet. We previously screened small-molecule compounds that inhibit hypoxia-induced cell death and identified 6-deoxyjacareubin. We hypothesized that the modulation of hypoxia signaling by 6-deoxyjacareubin might protect motor neurons in ALS. Here, we show that 6-deoxyjacareubin indeed ameliorates neurodegeneration in a mouse model of familial ALS. Administration of 6-deoxyjacareubin to this familial ALS model significantly attenuated disease progression and improved locomotor dysfunction. We also found that 6-deoxyjacareubin reduced motor neuron loss and glial activation. Our results indicate that 6-deoxyjacareubin might serve as a potential therapeutic tool for ALS. Moreover, these results suggest that modulation of hypoxia signaling pathways provides a promising strategy to develop therapies for other types of neurodegenerative diseases also characterized by hypoxia.
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Affiliation(s)
- Tomonori Hoshino
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Shu-Ichi Matsuzawa
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
| | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
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45
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Ding N, Jiang J, Tian H, Wang S, Li Z. Benign Regulation of the Astrocytic Phospholipase A 2-Arachidonic Acid Pathway: The Underlying Mechanism of the Beneficial Effects of Manual Acupuncture on CBF. Front Neurosci 2020; 13:1354. [PMID: 32174802 PMCID: PMC7054756 DOI: 10.3389/fnins.2019.01354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 12/02/2019] [Indexed: 12/19/2022] Open
Abstract
Background The astrocytic phospholipase A2 (PLA2)-arachidonic acid (AA) pathway is crucial in understanding the reduction of cerebral blood flow (CBF) prior to cognitive deterioration. In complementary and alternative medicine, manual acupuncture (MA) is used as one of the most important therapies for Alzheimer’s disease (AD). The beneficial effects of MA on CBF were reported in our previous study. However, the underlying molecular mechanism remains largely elusive. Objective To investigate the effect of MA on the astrocytic PLA2-AA pathway in SAMP8 mice hippocampi. Methods SAMP8 mice were divided into the SAMP8 control (Pc) group, the SAMP8 MA (Pm) group and the SAMP8 donepezil (Pd) group. SAMR1 mice were used as the SAMRl control (Rc) group. Mice in the Pd group were treated with donepezil hydrochloride at 0.65 μg/g. In the Pm group, MA was applied at Baihui (GV20) and Yintang (GV29) for 20 min. The above treatments were administered once a day for 26 consecutive days. The Morris water maze was applied to assess spatial learning and memory. Immunofluorescence staining, western blot and liquid chromatography-tandem mass spectrometry were used to investigate the expression of related proteins and measure the contents of the metabolic intermediates of the PLA2-AA pathway. Results Compared with that in the Rc group, the escape latency in the Pc group significantly increased (p < 0.01); whereas, the platform crossover number and percentage of time and swimming distance in the platform quadrant decreased (p < 0.01). The hippocampal expression of PLA2, cyclooxygenase-1, cytochrome P450 proteins 2C23 and the levels of AA, prostaglandin E2 and epoxyeicosatrienoic acids of the Pc group was drastically higher than that in the Rc group (p < 0.01). These changes were reversed by MA and donepezil (p < 0.01 or p < 0.05). Conclusion MA can effectively improve the learning and memory abilities of SAMP8 mice and has a negative regulatory effect on the PLA2-AA pathway. We propose that the increase of the arterial tone, which is induced by the inhibition of vasodilatory pathway, may be a reason for the beneficial effect of MA on CBF.
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Affiliation(s)
- Ning Ding
- Department of Acupuncture, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jing Jiang
- School of Nursing, Beijing University of Chinese Medicine, Beijing, China
| | - Huiling Tian
- School of Acupuncture, Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Shun Wang
- School of Acupuncture, Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Zhigang Li
- School of Acupuncture, Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
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46
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Taşkıran-Sağ A, Yemişçi M. Neuroinflammation in Alzheimer's disease continuum. NEUROL SCI NEUROPHYS 2020. [DOI: 10.4103/nsn.nsn_190_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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47
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Lu X, Moeini M, Li B, Lu Y, Damseh R, Pouliot P, Thorin É, Lesage F. A Pilot Study Investigating Changes in Capillary Hemodynamics and Its Modulation by Exercise in the APP-PS1 Alzheimer Mouse Model. Front Neurosci 2019; 13:1261. [PMID: 31920472 PMCID: PMC6915102 DOI: 10.3389/fnins.2019.01261] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
Dysfunction in neurovascular coupling that results in a mismatch between cerebral blood flow and neuronal activity has been suggested to play a key role in the pathogenesis of Alzheimer's disease (AD). Meanwhile, physical exercise is a powerful approach for maintaining cognitive health and could play a preventive role against the progression of AD. Given the fundamental role of capillaries in oxygen transport to tissue, our pilot study aimed to characterize changes in capillary hemodynamics with AD and AD supplemented by exercise. Exploiting two-photon microscopy, intrinsic signal optical imaging, and magnetic resonance imaging, we found hemodynamic alterations and lower vascular density with AD that were reversed by exercise. We further observed that capillary properties were branch order-dependent and that stimulation-evoked changes were attenuated with AD but increased by exercise. Our study provides novel indications into cerebral microcirculatory disturbances with AD and the modulating role of voluntary exercise on these alterations.
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Affiliation(s)
- Xuecong Lu
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Mohammad Moeini
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Yuankang Lu
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Rafat Damseh
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Philippe Pouliot
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Éric Thorin
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
- Department of Surgery, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Frédéric Lesage
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
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48
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Ngolab J, Honma P, Rissman RA. Reflections on the Utility of the Retina as a Biomarker for Alzheimer's Disease: A Literature Review. Neurol Ther 2019; 8:57-72. [PMID: 31833024 PMCID: PMC6908534 DOI: 10.1007/s40120-019-00173-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Indexed: 12/12/2022] Open
Abstract
As a part of the central nervous system, the retina may reflect both physiologic processes and abnormalities related to diseases of the brain. Indeed, a concerted effort has been put forth to understand how Alzheimer's disease (AD) pathology may manifest in the retina as a means to assess the state of the AD brain. The development and refinement of ophthalmologic techniques for studying the retina in vivo have produced evidence of retinal degeneration in AD diagnosed patients. In this review, we will discuss retinal imaging techniques implemented to study the changes in AD retina as well as highlight the recent efforts made to correlate such findings to other clinical hallmarks of AD to assess the viability of the retina as a biomarker for AD.
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Affiliation(s)
- Jennifer Ngolab
- Department of Neurosciences, University of California, San Diego, CA, USA
| | - Patrick Honma
- Department of Neurosciences, University of California, San Diego, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, CA, USA.
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Dalby RB, Eskildsen SF, Videbech P, Frandsen J, Mouridsen K, Sørensen L, Jeppesen P, Bek T, Rosenberg R, Østergaard L. Oxygenation differs among white matter hyperintensities, intersected fiber tracts and unaffected white matter. Brain Commun 2019; 1:fcz033. [PMID: 32954272 PMCID: PMC7425421 DOI: 10.1093/braincomms/fcz033] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 08/27/2019] [Accepted: 10/01/2019] [Indexed: 01/15/2023] Open
Abstract
White matter hyperintensities of presumed vascular origin are frequently observed on magnetic resonance imaging in normal aging. They are typically found in cerebral small vessel disease and suspected culprits in the etiology of complex age- and small vessel disease-related conditions, such as late-onset depression. White matter hyperintensities may interfere with surrounding white matter metabolic demands by disrupting fiber tract integrity. Meanwhile, risk factors for small vessel disease are thought to reduce tissue oxygenation, not only by reducing regional blood supply, but also by impairing capillary function. To address white matter oxygen supply–demand balance, we estimated voxel-wise capillary density as an index of resting white matter metabolism, and combined estimates of blood supply and capillary function to calculate white matter oxygen availability. We conducted a cross-sectional study with structural, perfusion- and diffusion-weighted magnetic resonance imaging in 21 patients with late-onset depression and 21 controls. We outlined white matter hyperintensities and used tractography to identify the tracts they intersect. Perfusion data comprised cerebral blood flow, blood volume, mean transit time and relative transit time heterogeneity—the latter a marker of capillary dysfunction. Based on these, white matter oxygenation was calculated as the steady state cerebral metabolic rate of oxygen under the assumption of normal tissue oxygen tension and vice versa. The number, volume and perfusion characteristics of white matter hyperintensities did not differ significantly between groups. Hemodynamic data showed white matter hyperintensities to have lower blood flow and blood volume, but higher relative transit time heterogeneity, than normal-appearing white matter, resulting in either reduced capillary metabolic rate of oxygen or oxygen tension. Intersected tracts showed significantly lower blood flow, blood volume and capillary metabolic rate of oxygen than normal-appearing white matter. Across groups, lower lesion oxygen tension was associated with higher lesion number and volume. Compared with normal-appearing white matter, tissue oxygenation is significantly reduced in white matter hyperintensities as well as the fiber tracts they intersect, independent of parallel late-onset depression. In white matter hyperintensities, reduced microvascular blood volume and concomitant capillary dysfunction indicate a severe oxygen supply–demand imbalance with hypoxic tissue injury. In intersected fiber tracts, parallel reductions in oxygenation and microvascular blood volume are consistent with adaptations to reduced metabolic demands. We speculate, that aging and vascular risk factors impair white matter hyperintensity perfusion and capillary function to create hypoxic tissue injury, which in turn affect the function and metabolic demands of the white matter tracts they disrupt.
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Affiliation(s)
- Rikke B Dalby
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark.,Centre for Psychiatric Research, Aarhus University Hospital, 8340 Risskov, Denmark.,Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Simon F Eskildsen
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark
| | - Poul Videbech
- Center for Neuropsychiatric Depression Research, Mental Health Center Glostrup, 2600 Glostrup, Denmark
| | - Jesper Frandsen
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark
| | - Kim Mouridsen
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark
| | - Leif Sørensen
- Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Peter Jeppesen
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Raben Rosenberg
- Centre of Psychiatry Amager, Mental Health Services in the Capital Region of Denmark, 2300 Copenhagen S., Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark.,Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus N., Denmark
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50
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Hachinski V, Einhäupl K, Ganten D, Alladi S, Brayne C, Stephan BCM, Sweeney MD, Zlokovic B, Iturria-Medina Y, Iadecola C, Nishimura N, Schaffer CB, Whitehead SN, Black SE, Østergaard L, Wardlaw J, Greenberg S, Friberg L, Norrving B, Rowe B, Joanette Y, Hacke W, Kuller L, Dichgans M, Endres M, Khachaturian ZS. Special topic section: linkages among cerebrovascular, cardiovascular, and cognitive disorders: Preventing dementia by preventing stroke: The Berlin Manifesto. Int J Stroke 2019:1747493019871915. [PMID: 31543058 DOI: 10.1177/1747493019871915] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The incidence of stroke and dementia are diverging across the world, rising for those in low-and middle-income countries and falling in those in high-income countries. This suggests that whatever factors cause these trends are potentially modifiable. At the population level, neurological disorders as a group account for the largest proportion of disability-adjusted life years globally (10%). Among neurological disorders, stroke (42%) and dementia (10%) dominate. Stroke and dementia confer risks for each other and share some of the same, largely modifiable, risk and protective factors. In principle, 90% of strokes and 35% of dementias have been estimated to be preventable. Because a stroke doubles the chance of developing dementia and stroke is more common than dementia, more than a third of dementias could be prevented by preventing stroke. Developments at the pathological, pathophysiological, and clinical level also point to new directions. Growing understanding of brain pathophysiology has unveiled the reciprocal interaction of cerebrovascular disease and neurodegeneration identifying new therapeutic targets to include protection of the endothelium, the blood-brain barrier, and other components of the neurovascular unit. In addition, targeting amyloid angiopathy aspects of inflammation and genetic manipulation hold new testable promise. In the meantime, accumulating evidence suggests that whole populations experiencing improved education, and lower vascular risk factor profiles (e.g., reduced prevalence of smoking) and vascular disease, including stroke, have better cognitive function and lower dementia rates. At the individual levels, trials have demonstrated that anticoagulation of atrial fibrillation can reduce the risk of dementia by 48% and that systolic blood pressure lower than 140 mmHg may be better for the brain. Based on these considerations, the World Stroke Organization has issued a proclamation, endorsed by all the major international organizations focused on global brain and cardiovascular health, calling for the joint prevention of stroke and dementia. This article summarizes the evidence for translation into action. © 2019 the Alzheimer's Association and the World Stroke Organisation. Published by Elsevier Inc. All rights reserved.
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Affiliation(s)
- Vladimir Hachinski
- Department of Clinical Neurological Sciences, Western University, Ontario, Canada
| | - Karl Einhäupl
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Detlev Ganten
- Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Suvarna Alladi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Carol Brayne
- Department of Public Health and Primary Care in the University of Cambridge, Cambridge, UK
| | - Blossom C M Stephan
- Institute of Mental Health, Division of Psychiatry and Applied Psychology, School of Medicine, University of Nottingham, Nottingham, UK
| | - Melanie D Sweeney
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Berislav Zlokovic
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Yasser Iturria-Medina
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Costantino Iadecola
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Nozomi Nishimura
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Shawn N Whitehead
- Department of Anatomy and Cell Biology, Western University, Ontario, Canada
| | - Sandra E Black
- Department of Medicine (Neurology), Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Leif Østergaard
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark
| | - Joanna Wardlaw
- Centre for Clinical Brain Sciences, Edinburgh Imaging, UK Dementia Research Institute, University of Edinburgh, Scotland, UK
| | - Steven Greenberg
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Leif Friberg
- Department of Clinical Sciences, Karolinska Institute, Stockholm, Sweden
| | - Bo Norrving
- Department of Clinical Sciences, Neurology, Lund University, Lund, Sweden
| | - Brian Rowe
- Department of Emergency Medicine and School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Yves Joanette
- Canadian Institute of Health and Research, Ottawa, Canada
| | - Werner Hacke
- Department of Neurology, Heidelberg University, Heidelberg, Germany
| | - Lewis Kuller
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Martin Dichgans
- Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig-Maximilians-Universität LMU, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE, Munich), Munich, Germany
| | - Matthias Endres
- Department of Neurology with Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Berlin, Germany
- ExcellenceCluster NeuroCure, Charité-Universitätsmedizin Berlin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), partner site Berlin, Berlin, Germany
- German Centre for Cardiovascular Research (DZHK), partner site Berlin, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
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