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Uekawa K, Anfray A, Ahn SJ, Casey N, Seo J, Zhou P, Iadecola C, Park L. tPA supplementation preserves neurovascular and cognitive function in Tg2576 mice. Alzheimers Dement 2024. [PMID: 38899570 DOI: 10.1002/alz.13878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 06/21/2024]
Abstract
INTRODUCTION Amyloid beta (Aβ) impairs the cerebral blood flow (CBF) increase induced by neural activity (functional hyperemia). Tissue plasminogen activator (tPA) is required for functional hyperemia, and in mouse models of Aβ accumulation tPA deficiency contributes to neurovascular and cognitive impairment. However, it remains unknown if tPA supplementation can rescue Aβ-induced neurovascular and cognitive dysfunction. METHODS Tg2576 mice and wild-type littermates received intranasal tPA (0.8 mg/kg/day) or vehicle 5 days a week starting at 11 to 12 months of age and were assessed 3 months later. RESULTS Treatment of Tg2576 mice with tPA restored resting CBF, prevented the attenuation in functional hyperemia, and improved nesting behavior. These effects were associated with reduced cerebral atrophy and cerebral amyloid angiopathy, but not parenchymal amyloid. DISCUSSION These findings highlight the key role of tPA deficiency in the neurovascular and cognitive dysfunction associated with amyloid pathology, and suggest potential therapeutic strategies involving tPA reconstitution. HIGHLIGHTS Amyloid beta (Aβ) induces neurovascular dysfunction and impairs the increase of cerebral blood flow induced by neural activity (functional hyperemia). Tissue plasminogen activator (tPA) deficiency contributes to the neurovascular and cognitive dysfunction caused by Aβ. In mice with florid amyloid pathology intranasal administration of tPA rescues the neurovascular and cognitive dysfunction and reduces brain atrophy and cerebral amyloid angiopathy. tPA deficiency plays a crucial role in neurovascular and cognitive dysfunction induced by Aβ and tPA reconstitution may be of therapeutic value.
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Affiliation(s)
- Ken Uekawa
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Antoine Anfray
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Sung Ji Ahn
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Nicole Casey
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - James Seo
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Ping Zhou
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Costantino Iadecola
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Laibaik Park
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
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Uekawa K, Hattori Y, Ahn SJ, Seo J, Casey N, Anfray A, Zhou P, Luo W, Anrather J, Park L, Iadecola C. Border-associated macrophages promote cerebral amyloid angiopathy and cognitive impairment through vascular oxidative stress. Mol Neurodegener 2023; 18:73. [PMID: 37789345 PMCID: PMC10548599 DOI: 10.1186/s13024-023-00660-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/20/2023] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND Cerebral amyloid angiopathy (CAA) is a devastating condition common in patients with Alzheimer's disease but also observed in the general population. Vascular oxidative stress and neurovascular dysfunction have been implicated in CAA but the cellular source of reactive oxygen species (ROS) and related signaling mechanisms remain unclear. We tested the hypothesis that brain border-associated macrophages (BAM), yolk sac-derived myeloid cells closely apposed to parenchymal and leptomeningeal blood vessels, are the source of radicals through the Aβ-binding innate immunity receptor CD36, leading to neurovascular dysfunction, CAA, and cognitive impairment. METHODS Tg2576 mice and WT littermates were transplanted with CD36-/- or CD36+/+ bone marrow at 12-month of age and tested at 15 months. This approach enables the repopulation of perivascular and leptomeningeal compartments with CD36-/- BAM. Neurovascular function was tested in anesthetized mice equipped with a cranial window in which cerebral blood flow was monitored by laser-Doppler flowmetry. Amyloid pathology and cognitive function were also examined. RESULTS The increase in blood flow evoked by whisker stimulation (functional hyperemia) or by endothelial and smooth muscle vasoactivity was markedly attenuated in WT → Tg2576 chimeras but was fully restored in CD36-/- → Tg2576 chimeras, in which BAM ROS production was suppressed. CAA-associated Aβ1-40, but not Aβ1-42, was reduced in CD36-/- → Tg2576 chimeras. Similarly, CAA, but not parenchymal plaques, was reduced in CD36-/- → Tg2576 chimeras. These beneficial vascular effects were associated with cognitive improvement. Finally, CD36-/- mice were able to more efficiently clear exogenous Aβ1-40 injected into the neocortex or the striatum. CONCLUSIONS CD36 deletion in BAM suppresses ROS production and rescues the neurovascular dysfunction and damage induced by Aβ. CD36 deletion in BAM also reduced brain Aβ1-40 and ameliorated CAA without affecting parenchyma plaques. Lack of CD36 enhanced the vascular clearance of exogenous Aβ. Restoration of neurovascular function and attenuation of CAA resulted in a near complete rescue of cognitive function. Collectively, these data implicate brain BAM in the pathogenesis of CAA and raise the possibility that targeting BAM CD36 is beneficial in CAA and other conditions associated with vascular Aβ deposition and damage.
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Affiliation(s)
- Ken Uekawa
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Yorito Hattori
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Sung Ji Ahn
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - James Seo
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Nicole Casey
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Antoine Anfray
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Ping Zhou
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Wenjie Luo
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Josef Anrather
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Laibaik Park
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA.
| | - Costantino Iadecola
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA.
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Xue Y, Tang J, Zhang M, He Y, Fu J, Ding F. Durative sleep fragmentation with or without hypertension suppress rapid eye movement sleep and generate cerebrovascular dysfunction. Neurobiol Dis 2023:106222. [PMID: 37419254 DOI: 10.1016/j.nbd.2023.106222] [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: 01/02/2023] [Revised: 06/07/2023] [Accepted: 07/04/2023] [Indexed: 07/09/2023] Open
Abstract
Either hypertension or chronic insomnia is the risk factor of developing vascular dementia. Durative hypertension can induce vascular remodeling and is used for modeling small vessel disease in rodents. It remains undetermined if the combination of hypertension and sleep disturbance exacerbates vascular dysfunction or pathologies. Previously, we found chronic sleep fragmentation (SF) dampened cognition in young mice without disease predispositions. In the current study, we superimposed SF with hypertension modeling in young mice. Angiotensin II (AngII)-releasing osmotic mini pumps were subcutaneously implanted to generate persistent hypertension, while sham surgeries were performed as controls. Sleep fragmentation with repetitive arousals (10 s every 2 min) during light-on 12 h for consecutive 30 days, while mice undergoing normal sleep (NS) processes were set as controls. Sleep architectures, whisker-stimulated cerebral blood flow (CBF) changes, vascular responsiveness as well as vascular pathologies were compared among normal sleep plus sham (NS + sham), SF plus sham (SF + sham), normal sleep plus AngII (NS + AngII), and SF plus AngII (SF + AngII) groups. SF and hypertension both alter sleep structures, particularly suppressing REM sleep. SF no matter if combined with hypertension strongly suppressed whisker-stimulated CBF increase, suggesting the tight association with cognitive decline. Hypertension modeling sensitizes vascular responsiveness toward a vasoactive agent, Acetylcholine (ACh, 5 mg/ml, 10 μl) delivered via cisterna magna infusion, while SF exhibits a similar but much milder effect. None of the modeling above was sufficient to induce arterial or arteriole vascular remodeling, but SF or SF plus hypertension increased vascular network density constructed by all categories of cerebral vessels. The current study would potentially help understand the pathogenesis of vascular dementia, and the interconnection between sleep and vascular health.
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Affiliation(s)
- Yang Xue
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200032, China
| | - Jie Tang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200032, China
| | - Miaoyi Zhang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200032, China
| | - Yifan He
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Jianhui Fu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200032, China.
| | - Fengfei Ding
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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Holstein-Rønsbo S, Gan Y, Giannetto MJ, Rasmussen MK, Sigurdsson B, Beinlich FRM, Rose L, Untiet V, Hablitz LM, Kelley DH, Nedergaard M. Glymphatic influx and clearance are accelerated by neurovascular coupling. Nat Neurosci 2023; 26:1042-1053. [PMID: 37264158 PMCID: PMC10500159 DOI: 10.1038/s41593-023-01327-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 04/12/2023] [Indexed: 06/03/2023]
Abstract
Functional hyperemia, also known as neurovascular coupling, is a phenomenon that occurs when neural activity increases local cerebral blood flow. Because all biological activity produces metabolic waste, we here sought to investigate the relationship between functional hyperemia and waste clearance via the glymphatic system. The analysis showed that whisker stimulation increased both glymphatic influx and clearance in the mouse somatosensory cortex with a 1.6-fold increase in periarterial cerebrospinal fluid (CSF) influx velocity in the activated hemisphere. Particle tracking velocimetry revealed a direct coupling between arterial dilation/constriction and periarterial CSF flow velocity. Optogenetic manipulation of vascular smooth muscle cells enhanced glymphatic influx in the absence of neural activation. We propose that impedance pumping allows arterial pulsatility to drive CSF in the same direction as blood flow, and we present a simulation that supports this idea. Thus, functional hyperemia boosts not only the supply of metabolites but also the removal of metabolic waste.
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Affiliation(s)
| | - Yiming Gan
- Department of Mechanical Engineering, University of Rochester Medical Center, Rochester, NY, USA
| | - Michael J Giannetto
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, University of Rochester Medical Center, Rochester, NY, USA
| | - Martin Kaag Rasmussen
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Björn Sigurdsson
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Laura Rose
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Verena Untiet
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, University of Rochester Medical Center, Rochester, NY, USA
| | - Douglas H Kelley
- Department of Mechanical Engineering, University of Rochester Medical Center, Rochester, NY, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark.
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, University of Rochester Medical Center, Rochester, NY, USA.
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Uekawa K, Hattori Y, Ahn SJ, Seo J, Casey N, Anfray A, Zhou P, Luo W, Anrather J, Park L, Iadecola C. Border-associated macrophages promote cerebral amyloid angiopathy and cognitive impairment through vascular oxidative stress. RESEARCH SQUARE 2023:rs.3.rs-2719812. [PMID: 37162996 PMCID: PMC10168479 DOI: 10.21203/rs.3.rs-2719812/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Background: Cerebral amyloid angiopathy (CAA) is a devastating condition common in patients with Alzheimer's disease but also observed in the general population. Vascular oxidative stress and neurovascular dysfunction have been implicated in CAA but the cellular source of reactive oxygen species (ROS) and related signaling mechanisms remain unclear. We tested the hypothesis that brain border-associated macrophages (BAM), yolk sac-derived myeloid cells closely apposed to parenchymal and leptomeningeal blood vessels, are the source of radicals through the Aβ-binding innate immunity receptor CD36, leading to neurovascular dysfunction, CAA, and cognitive impairment. Methods: Tg2576 mice and WT littermates were transplanted with CD36 -/- or CD36 +/+ bone marrow at 12-month of age and tested at 15 months. This approach enables the repopulation of perivascular and leptomeningeal compartments with CD36 -/- BAM. Neurovascular function was tested in anesthetized mice equipped with a cranial window in which cerebral blood flow was monitored by laser-Doppler flowmetry. Amyloid pathology and cognitive function were also examined. Results: The increase in blood flow evoked by whisker stimulation (functional hyperemia) or by endothelial and smooth muscle vasoactivity was markedly attenuated in WT®Tg2576 chimeras but was fully restored in CD36 -/- ®Tg2576 chimeras, in which BAM ROS production was suppressed. CAA-associated Aβ 1-40 , but not Aβ 1-42 , was reduced in CD36 -/- ®Tg2576 chimeras. Similarly, CAA, but not parenchymal plaques, was reduced in CD36 -/- ®Tg2576 chimeras. These beneficial vascular effects were associated with cognitive improvement. Finally, CD36 -/- mice were able to more efficiently clear exogenous Aβ 1-40 injected into the neocortex or the striatum. Conclusions: CD36 deletion in BAM suppresses ROS production and rescues the neurovascular dysfunction and damage induced by Aβ. CD36 deletion in BAM also reduced brain Aβ 1-40 and ameliorated CAA without affecting parenchyma plaques. Lack of CD36 enhanced the vascular clearance of exogenous Aβ. Restoration of neurovascular function and attenuation of CAA resulted in a near complete rescue of cognitive function. Collectively, these data implicate CNS BAM in the pathogenesis of CAA and raise the possibility that targeting BAM CD36 is beneficial in CAA and other conditions associated with vascular Aβ deposition and damage.
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Lista S, Vergallo A, Teipel SJ, Lemercier P, Giorgi FS, Gabelle A, Garaci F, Mercuri NB, Babiloni C, Gaire BP, Koronyo Y, Koronyo-Hamaoui M, Hampel H, Nisticò R. Determinants of approved acetylcholinesterase inhibitor response outcomes in Alzheimer's disease: relevance for precision medicine in neurodegenerative diseases. Ageing Res Rev 2023; 84:101819. [PMID: 36526257 DOI: 10.1016/j.arr.2022.101819] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/11/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022]
Abstract
Acetylcholinesterase inhibitors (ChEI) are the global standard of care for the symptomatic treatment of Alzheimer's disease (AD) and show significant positive effects in neurodegenerative diseases with cognitive and behavioral symptoms. Although experimental and large-scale clinical evidence indicates the potential long-term efficacy of ChEI, primary outcomes are generally heterogeneous across outpatient clinics and regional healthcare systems. Sub-optimal dosing or slow tapering, heterogeneous guidelines about the timing for therapy initiation (prodromal versus dementia stages), healthcare providers' ambivalence to treatment, lack of disease awareness, delayed medical consultation, prescription of ChEI in non-AD cognitive disorders, contribute to the negative outcomes. We present an evidence-based overview of determinants, spanning genetic, molecular, and large-scale networks, involved in the response to ChEI in patients with AD and other neurodegenerative diseases. A comprehensive understanding of cerebral and retinal cholinergic system dysfunctions along with ChEI response predictors in AD is crucial since disease-modifying therapies will frequently be prescribed in combination with ChEI. Therapeutic algorithms tailored to genetic, biological, clinical (endo)phenotypes, and disease stages will help leverage inter-drug synergy and attain optimal combined response outcomes, in line with the precision medicine model.
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Affiliation(s)
- Simone Lista
- Memory Resources and Research Center (CMRR), Neurology Department, Gui de Chauliac University Hospital, Montpellier, France; School of Pharmacy, University of Rome "Tor Vergata", Rome, Italy.
| | - Andrea Vergallo
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Stefan J Teipel
- German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald, Rostock, Germany; Department of Psychosomatic Medicine and Psychotherapy, University Medicine Rostock, Rostock, Germany
| | - Pablo Lemercier
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Filippo Sean Giorgi
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Audrey Gabelle
- Memory Resources and Research Center (CMRR), Neurology Department, Gui de Chauliac University Hospital, Montpellier, France
| | - Francesco Garaci
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy; Casa di Cura "San Raffaele Cassino", Cassino, Italy
| | - Nicola B Mercuri
- Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy; IRCCS Santa Lucia Foundation, Rome, Italy
| | - Claudio Babiloni
- Department of Physiology and Pharmacology "Erspamer", Sapienza University of Rome, Rome, Italy; Hospital San Raffaele Cassino, Cassino, Italy
| | - Bhakta Prasad Gaire
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Department of Biomedical Sciences, Division of Applied Cell Biology and Physiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Harald Hampel
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Robert Nisticò
- School of Pharmacy, University of Rome "Tor Vergata", Rome, Italy; Laboratory of Pharmacology of Synaptic Plasticity, EBRI Rita Levi-Montalcini Foundation, Rome, Italy.
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Functionally linked potassium channel activity in cerebral endothelial and smooth muscle cells is compromised in Alzheimer's disease. Proc Natl Acad Sci U S A 2022; 119:e2204581119. [PMID: 35727988 PMCID: PMC9245656 DOI: 10.1073/pnas.2204581119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Patients with Alzheimer’s disease show hypoperfusion of the brain and this may contribute to disease progression. To elucidate underlying mechanisms, we studied pial arteries from 18-mo-old mice with Alzheimer’s disease due to overexpression of amyloid precursor protein. We found enhanced pressure-induced constriction of arteries because of reduction in ryanodine receptor-mediated, local calcium-release events (“Ca2+ sparks”) in arterial smooth muscle cells and a consequent decrease in the activity of large-conductance Ca2+-activated K+ (BK) channels. This phenotype was partially recapitulated by application of an amyloid-β peptide to healthy arteries. Our results will direct further research to restore cerebrovascular function, which is damaged in Alzheimer’s disease, leading to potentially new treatment options. The brain microcirculation is increasingly viewed as a potential target for disease-modifying drugs in the treatment of Alzheimer’s disease patients, reflecting a growing appreciation of evidence that cerebral blood flow is compromised in such patients. However, the pathogenic mechanisms in brain resistance arteries underlying blood flow defects have not yet been elucidated. Here we probed the roles of principal vasodilatory pathways in cerebral arteries using the APP23 mouse model of Alzheimer’s disease, in which amyloid precursor protein is increased approximately sevenfold, leading to neuritic plaques and cerebrovascular accumulation of amyloid-β similar to those in patients with Alzheimer’s disease. Pial arteries from APP23 mice (18 mo old) exhibited enhanced pressure-induced (myogenic) constriction because of a profound reduction in ryanodine receptor-mediated, local calcium-release events (“Ca2+ sparks”) in arterial smooth muscle cells and a consequent decrease in the activity of large-conductance Ca2+-activated K+ (BK) channels. The ability of the endothelial cell inward rectifier K+ (Kir2.1) channel to cause dilation was also compromised. Acute application of amyloid-β 1-40 peptide to cerebral arteries from wild-type mice partially recapitulated the BK dysfunction seen in APP23 mice but had no effect on Kir2.1 function. If mirrored in human Alzheimer’s disease, these tandem defects in K+ channel-mediated vasodilation could account for the clinical cerebrovascular presentation seen in patients: reduced blood flow and crippled functional hyperemia. These data direct future research toward approaches that reverse this dual vascular channel dysfunction, with the ultimate aim of restoring healthy cerebral blood flow and improving clinical outcomes.
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Hippocampal cerebral blood flow increased following low-pressure hyperbaric oxygenation in firefighters with mild traumatic brain injury and emotional distress. Neurol Sci 2021; 42:4131-4138. [PMID: 33532950 DOI: 10.1007/s10072-021-05094-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/27/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND Recent evidence suggests that hyperbaric oxygenation (HBO), which has been used as an effective treatment for certain types of tissue injury, may change neural activities in the human brain and subsequently improve symptoms of psychiatric disorders. To scrutinize the neural mechanism of HBO in the human brain, we investigated whether 20 sessions of HBO changed regional cerebral blood flow (rCBF) of the limbic system in firefighters with mild traumatic brain injury (mTBI) and subjective emotional distress. METHODS Twenty firefighters with mTBI and mild emotional distress were treated with HBO at a relatively low pressure of 1.3 atmospheres absolute for 45 min a day for 20 consecutive days (the mild emotional distress group). The rCBF of the limbic system was measured using an arterial spin labeling perfusion magnetic resonance imaging before and after the HBO. Analyses were performed on the data from fourteen individuals who completed the study and 14 age- and sex-matched healthy firefighters (the comparison group). RESULTS Firefighters in the mild emotional distress group showed increase rCBF following HBO in a cluster encompassing the right hippocampal and parahippocampal regions (peak t = 4.31; cluster size = 248 mm3)(post-hoc analysis, z = 5.92, p < 0.001) that had lower rCBF relative to the comparison group at baseline (post-hoc analysis, t = -2.20, p = 0.04). CONCLUSION The current study demonstrated that low-pressure HBO might increase rCBF of the hippocampal and parahippocampal regions, suggesting a potential underpinning mechanism of HBO in the human brain.
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Solis E, Hascup KN, Hascup ER. Alzheimer's Disease: The Link Between Amyloid-β and Neurovascular Dysfunction. J Alzheimers Dis 2020; 76:1179-1198. [PMID: 32597813 PMCID: PMC7483596 DOI: 10.3233/jad-200473] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
While prevailing evidence supports that the amyloid cascade hypothesis is a key component of Alzheimer's disease (AD) pathology, many recent studies indicate that the vascular system is also a major contributor to disease progression. Vascular dysfunction and reduced cerebral blood flow (CBF) occur prior to the accumulation and aggregation of amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles. Although research has predominantly focused on the cellular processes involved with Aβ-mediated neurodegeneration, effects of Aβ on CBF and neurovascular coupling are becoming more evident. This review will describe AD vascular disturbances as they relate to Aβ, including chronic cerebral hypoperfusion, hypertension, altered neurovascular coupling, and deterioration of the blood-brain barrier. In addition, we will describe recent findings about the relationship between these vascular defects and Aβ accumulation with emphasis on in vivo studies utilizing rodent AD models.
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Affiliation(s)
- Ernesto Solis
- Department of Neurology, Neuroscience Institute, Center for Alzheimer’s Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Kevin N. Hascup
- Department of Neurology, Neuroscience Institute, Center for Alzheimer’s Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield, IL, USA
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
- Department of Medical Microbiology, Immunology, and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Erin R. Hascup
- Department of Neurology, Neuroscience Institute, Center for Alzheimer’s Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield, IL, USA
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
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Kelly P, Hudry E, Hou SS, Bacskai BJ. In Vivo Two Photon Imaging of Astrocytic Structure and Function in Alzheimer's Disease. Front Aging Neurosci 2018; 10:219. [PMID: 30072889 PMCID: PMC6060286 DOI: 10.3389/fnagi.2018.00219] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/26/2018] [Indexed: 12/17/2022] Open
Abstract
The physiological function of the neurovascular unit is critically dependent upon the complex structure and functions of astrocytes for optimal preservation of cerebral homeostasis. While it has been shown that astrocytes exhibit aberrant changes in both structure and function in transgenic murine models of Alzheimer’s disease (AD), it is not fully understood how this altered phenotype contributes to the pathogenesis of AD or whether this alteration predicts a therapeutic target in AD. The mechanisms underlying the spatiotemporal relationship between astrocytes, neurons and the vasculature in their orchestrated regulation of local cerebral flow in active brain regions has not been fully elucidated in brain physiology and in AD. As there is an incredible urgency to identify therapeutic targets that are well-tolerated and efficacious in protecting the brain against the pathological impact of AD, here we use the current body of literature to evaluate the hypothesis that pathological changes in astrocytes are central to the pathogenesis of AD. We also examine the current tools available to assess astrocytic calcium signaling in the living murine brain as it has an important role in the complex interaction between astrocytes, neurons and the vasculature. Furthermore, we discuss the altered function of astrocytes in their interaction with neurons in the preservation of glutamate homeostasis and additionally address the role of astrocytes at the vascular interface and their contribution to functional hyperemia within the living murine brain in health and in AD.
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Affiliation(s)
- Patricia Kelly
- Massachusetts Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Eloise Hudry
- Massachusetts Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Steven S Hou
- Massachusetts Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Brian J Bacskai
- Massachusetts Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, United States
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Guo H, Grajauskas L, Habash B, D'Arcy RCN, Song X. Functional MRI technologies in the study of medication treatment effect on Alzheimer's disease. Aging Med (Milton) 2018; 1:75-95. [PMID: 31942484 PMCID: PMC6880690 DOI: 10.1002/agm2.12017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/02/2018] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of late-life dementia. Characterized by progressive neurodegeneration, the disease is expressed as gradual memory loss together with decline in cognitive abilities and other brain functions. Despite extensive research over the past decade, the cause and cure of AD both remain largely unknown. Several AD-associated deficits have been targeted for interventions, including those based on amyloid-beta, tau, and inflammation hypotheses. Only 2 types of medications-cholinesterase inhibitors and memantine-have been approved, to control the cognitive symptoms of AD such as the loss of memory, language, and executive function. Noninvasive in vivo functional magnetic resonance imaging (MRI) technologies, including the blood oxygen level-dependent functional MRI, arterial spin labeling-based perfusion MRI, and the proton magnetic resonance spectroscopy have been used to study the effect of ChEIs and memantine in the brain. Most of these studies have demonstrated increased functional activation and connectivity, increased regional brain blood flow and volume post-treatment, and positive responses of critical brain metabolites reflecting neuronal status and functionality in patients with AD and mild cognitive impairment. The findings have contributed to the understanding of the mechanisms underlying the medication treatments and support the crucial role of functional MRI technologies in the development and refinement of AD medication therapies.
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Affiliation(s)
- Hui Guo
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Diagnostic ImagingTianjin Medical University General HospitalTianjinChina
| | - Lukas Grajauskas
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
| | - Baraa Habash
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Ryan CN D'Arcy
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
- Department of Computing ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Xiaowei Song
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
- Department of Computing ScienceSimon Fraser UniversityBurnabyBCCanada
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12
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Kotliar K, Hauser C, Ortner M, Muggenthaler C, Diehl-Schmid J, Angermann S, Hapfelmeier A, Schmaderer C, Grimmer T. Altered neurovascular coupling as measured by optical imaging: a biomarker for Alzheimer's disease. Sci Rep 2017; 7:12906. [PMID: 29018233 PMCID: PMC5635105 DOI: 10.1038/s41598-017-13349-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/21/2017] [Indexed: 11/22/2022] Open
Abstract
Neurovascular coupling can be directly assessed by retinal vessel response to flickering light using optical imaging methods. The response is altered in a number of ocular and cardiovascular diseases. Whether it is altered in Alzheimer's disease (AD) is investigated. Retinal vessel reaction to monochromatic flicker stimulation was examined by Dynamic Vessel Analyzer independent of the commercial software in elderly subjects: 15 patients with mild-to-moderate dementia due to AD (ADD); 24 patients with mild cognitive impairment due to AD (MCI); 15 cognitively healthy controls (HC). Retinal vessels in ADD showed a more emphasized and delayed reactive dilation as compared to HC. In MCI, these aspects still differed from those seen in ADD. Maximal arterial reaction was increased and dilation was delayed in ADD as compared to HC (p = 0.004 and p < 0.001) and to MCI (p = 0.058 and p = 0.004), respectively. Maximal venous reaction was increased in ADD as compared to HC (p = 0.001) and to MCI (p = 0.007), respectively. This finding suggests that retinal neuronal activity is either increased or feed-back loop of neurovascular coupling is damaged with differentiating alterations across the spectrum of AD. Thus, retinal vessel reaction to flicker stimulation is considered a promising non-invasive, widely available and easy-to-administer future biomarker for the diagnosis and monitoring of AD.
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Affiliation(s)
- Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Campus Jülich, Heinrich-Mussmann-Str. 1, 52428, Jülich, Germany
- Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Christine Hauser
- Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Marion Ortner
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Claudia Muggenthaler
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Janine Diehl-Schmid
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Susanne Angermann
- Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Alexander Hapfelmeier
- Institute of Medical Statistics and Epidemiology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Christoph Schmaderer
- Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Timo Grimmer
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
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13
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Thomas BP, Sheng M, Tseng BY, Tarumi T, Martin-Cook K, Womack KB, Cullum MC, Levine BD, Zhang R, Lu H. Reduced global brain metabolism but maintained vascular function in amnestic mild cognitive impairment. J Cereb Blood Flow Metab 2017; 37:1508-1516. [PMID: 27389176 PMCID: PMC5453471 DOI: 10.1177/0271678x16658662] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Amnestic mild cognitive impairment represents an early stage of Alzheimer's disease, and characterization of physiological alterations in mild cognitive impairment is an important step toward accurate diagnosis and intervention of this condition. To investigate the extent of neurodegeneration in patients with mild cognitive impairment, whole-brain cerebral metabolic rate of oxygen in absolute units of µmol O2/min/100 g was quantified in 44 amnestic mild cognitive impairment and 28 elderly controls using a novel, non-invasive magnetic resonance imaging method. We found a 12.9% reduction ( p = 0.004) in cerebral metabolic rate of oxygen in mild cognitive impairment, which was primarily attributed to a reduction in the oxygen extraction fraction, by 10% ( p = 0.016). Global cerebral blood flow was not found to be different between groups. Another aspect of vascular function, cerebrovascular reactivity, was measured by CO2-inhalation magnetic resonance imaging and was found to be equivalent between groups. Therefore, there seems to be a global, diffuse diminishment in neural function in mild cognitive impairment, while their vascular function did not show a significant reduction.
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Affiliation(s)
- Binu P Thomas
- 1 Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Min Sheng
- 1 Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Benjamin Y Tseng
- 2 Institute of Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
| | - Takashi Tarumi
- 2 Institute of Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
| | - Kristen Martin-Cook
- 3 Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kyle B Womack
- 3 Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Munro C Cullum
- 3 Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,4 Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Benjamin D Levine
- 2 Institute of Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
| | - Rong Zhang
- 2 Institute of Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA.,3 Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hanzhang Lu
- 1 Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,5 Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
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14
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Toth P, Tarantini S, Csiszar A, Ungvari Z. Functional vascular contributions to cognitive impairment and dementia: mechanisms and consequences of cerebral autoregulatory dysfunction, endothelial impairment, and neurovascular uncoupling in aging. Am J Physiol Heart Circ Physiol 2017; 312:H1-H20. [PMID: 27793855 PMCID: PMC5283909 DOI: 10.1152/ajpheart.00581.2016] [Citation(s) in RCA: 319] [Impact Index Per Article: 45.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/10/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022]
Abstract
Increasing evidence from epidemiological, clinical and experimental studies indicate that age-related cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including Alzheimer's disease. Understanding and targeting the age-related pathophysiological mechanisms that underlie vascular contributions to cognitive impairment and dementia (VCID) are expected to have a major role in preserving brain health in older individuals. Maintenance of cerebral perfusion, protecting the microcirculation from high pressure-induced damage and moment-to-moment adjustment of regional oxygen and nutrient supply to changes in demand are prerequisites for the prevention of cerebral ischemia and neuronal dysfunction. This overview discusses age-related alterations in three main regulatory paradigms involved in the regulation of cerebral blood flow (CBF): cerebral autoregulation/myogenic constriction, endothelium-dependent vasomotor function, and neurovascular coupling responses responsible for functional hyperemia. The pathophysiological consequences of cerebral microvascular dysregulation in aging are explored, including blood-brain barrier disruption, neuroinflammation, exacerbation of neurodegeneration, development of cerebral microhemorrhages, microvascular rarefaction, and ischemic neuronal dysfunction and damage. Due to the widespread attention that VCID has captured in recent years, the evidence for the causal role of cerebral microvascular dysregulation in cognitive decline is critically examined.
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Affiliation(s)
- Peter Toth
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Pecs, Hungary; and
| | - Stefano Tarantini
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Anna Csiszar
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma;
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
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15
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Daulatzai MA. Dysfunctional Sensory Modalities, Locus Coeruleus, and Basal Forebrain: Early Determinants that Promote Neuropathogenesis of Cognitive and Memory Decline and Alzheimer’s Disease. Neurotox Res 2016; 30:295-337. [DOI: 10.1007/s12640-016-9643-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 12/22/2022]
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16
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Iulita MF, Girouard H. Treating Hypertension to Prevent Cognitive Decline and Dementia: Re-Opening the Debate. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 956:447-473. [DOI: 10.1007/5584_2016_98] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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