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Mamelak M. The Alzheimer's Disease Brain, Its Microvasculature, and NADPH Oxidase. J Alzheimers Dis 2024; 99:S109-S118. [PMID: 37599534 DOI: 10.3233/jad-230415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
The deterioration of the brain's microvasculature, particularly in the hippocampus, appears to be a very early event in the development of Alzheimer's disease (AD), preceding even the deposition of amyloid-β. A damaged microvasculature reduces the supply of oxygen and glucose to this region and limits the production of energy, ATP. The damage may be a function of the rise with age in the expression and activity of NADPH oxidase (NOX) in these microvessels. This rise renders these vessels vulnerable to the effects of oxidative stress and inflammation. The rise in NOX activity with age is even more marked in the AD brain where an inverse correlation has been demonstrated between NOX activity and cognitive ability. Apocynin, a putative NOX inhibitor, has been shown to block the damaging effects of NOX activation. Apocynin acts as a strong scavenger of H2O2, and as a weak scavenger of superoxide. Like apocynin, sodium oxybate (SO) has also been shown to block the toxic effects of NOX activation. The application of SO generates NADPH and ATP. SO inhibits oxidative stress and maintains normal cerebral ATP levels under hypoxic conditions. Moreover, it acts epigenetically to attenuate the expression of NOX. SO may delay the onset and slow the progress of AD by suppling energy and maintaining an antioxidative environment in the brain throughout the night. The slow wave activity produced by SO may also activate the glymphatic system and promote the clearance of amyloid-β from the brain.
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Affiliation(s)
- Mortimer Mamelak
- Department of Psychiatry, Baycrest Hospital, University of Toronto, Toronto, Ontario, Canada
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2
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Tonni G, Pinto A, Bianchi A, Pisello M, Grisolia G. 3D ultrasound angioscan with MV-Flow™: Enhancing fetal brain low-flow microvascular neuroimaging. J Clin Ultrasound 2023; 51:1502-1504. [PMID: 37728339 DOI: 10.1002/jcu.23563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/21/2023]
Abstract
MVFlow™ is a 3D algorithm that enhances the study of the microvasculature, useful in the study of tumoral lesions or in assessing the slow-flow of the placenta vessels and the developing fetal brain. It may improve the study of the corpus callosum in normal fetuses and be applied in the characterization of brain pathologies.
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Affiliation(s)
- Gabriele Tonni
- Department of Obstetrics and Neonatology, and Researcher, Istituto di Ricovero e Cura a Carattere Scientifico, Azienda Unita' Sanitaria Locale di Reggio Emilia, Reggio Emilia, Italy
| | - Alessia Pinto
- Department of Obstetrics and Gynecology, Carlo Poma Hospital, Azienda Socio Sanitaria Territoriale di Mantova, Mantua, Italy
| | - Annalisa Bianchi
- Department of Obstetrics and Gynecology, Carlo Poma Hospital, Azienda Socio Sanitaria Territoriale di Mantova, Mantua, Italy
| | - Marlene Pisello
- Department of Obstetrics and Gynecology, Carlo Poma Hospital, Azienda Socio Sanitaria Territoriale di Mantova, Mantua, Italy
| | - Gianpaolo Grisolia
- Department of Obstetrics and Gynecology, Carlo Poma Hospital, Azienda Socio Sanitaria Territoriale di Mantova, Mantua, Italy
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Baker J, Safarzadeh MA, Incognito AV, Jendzjowsky NG, Foster GE, Bird JD, Raj SR, Day TA, Rickards CA, Zubieta-DeUrioste N, Alim U, Wilson RJA. Functional optical coherence tomography at altitude: retinal microvascular perfusion and retinal thickness at 3,800 meters. J Appl Physiol (1985) 2022; 133:534-545. [PMID: 35771223 DOI: 10.1152/japplphysiol.00132.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral hypoxia is a serious consequence of several cardiorespiratory illnesses. Measuring the retinal microvasculature at high altitude provides a surrogate for cerebral microvasculature, offering potential insight into cerebral hypoxia in critical illness. Additionally, while sex-specific differences in cardiovascular diseases are strongly supported, few have focused on differences in ocular blood flow. We evaluated the retinal microvasculature in males (n=11) and females (n=7) using functional optical coherence tomography at baseline (1,130m) (Day 0), following rapid ascent (Day 2) and prolonged exposure (Day 9) to high altitude (3,800m). Retinal vascular perfusion density (rVPD; an index of total blood supply), retinal thickness (RT; reflecting vascular and neural tissue volume) and arterial blood were acquired. As a group, rVPD increased on Day 2 vs. Day 0 (p<0.001) and was inversely related to PaO2 (R2=0.45; p=0.006). By Day 9, rVPD recovered to baseline, but was significantly lower in males vs. females (p=0.007). RT was not different on Day 2 vs. Day 0 (p>0.99) but was reduced by Day 9 relative to Day 0 and Day 2 (p<0.001). RT changes relative to Day 0 were inversely related to changes in PaO2 on Day 2 (R2=0.6; p=0.001) and Day 9 (R2=0.4; p=0.02). RT did not differ between sexes. These data suggest differential time course and regulation of the retina during rapid ascent and prolonged exposure to high altitude and are the first to demonstrate sex-specific differences in rVPD at high altitude. The ability to assess intact microvasculature contiguous with the brain has widespread research and clinical applications.
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Affiliation(s)
- Jacquie Baker
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Mohammad Amin Safarzadeh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Anthony V Incognito
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Nicholas G Jendzjowsky
- Division of Respiratory and Critical Care Physiology and Medicine, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States
| | - Glen Edward Foster
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Jordan D Bird
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Satish R Raj
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Caroline A Rickards
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Natalia Zubieta-DeUrioste
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,High Altitude Pulmonary and Pathology Institute (HAPPI - IPPA), La Paz, Bolivia
| | - Usman Alim
- Department of Computer Science, University of Calgary, Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
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Suwannasual U, Lucero J, Davis G, McDonald JD, Lund AK. Mixed Vehicle Emissions Induces Angiotensin II and Cerebral Microvascular Angiotensin Receptor Expression in C57Bl/6 Mice and Promotes Alterations in Integrity in a Blood-Brain Barrier Coculture Model. Toxicol Sci 2020; 170:525-535. [PMID: 31132127 DOI: 10.1093/toxsci/kfz121] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Exposure to traffic-generated pollution is associated with alterations in blood-brain barrier (BBB) integrity and exacerbation of cerebrovascular disorders. Angiotensin (Ang) II signaling through the Ang II type 1 (AT1) receptor is known to promote BBB disruption. We have previously reported that exposure to a mixture of gasoline and diesel vehicle engine emissions (MVE) mediates alterations in cerebral microvasculature of C57Bl/6 mice, which is exacerbated through consumption of a high-fat (HF) diet. Thus, we investigated the hypothesis that inhalation exposure to MVE results in altered central nervous system microvascular integrity mediated by Ang II-AT1 signaling. Three-month-old male C57Bl/6 mice were placed on an HF or low-fat diet and exposed via inhalation to either filtered air (FA) or MVE (100 μg/m3 PM) 6 h/d for 30 days. Exposure to HF+MVE resulted in a significant increase in plasma Ang II and expression of AT1 in the cerebral microvasculature. Results from a BBB coculture study showed that transendothelial electrical resistance was decreased, associated with reduced expression of claudin-5 and occludin when treated with plasma from MVE+HF animals. These effects were attenuated through pretreatment with the AT1 antagonist, Losartan. Our BBB coculture showed increased levels of astrocyte AT1 and decreased expression of aryl hydrocarbon receptor and glutathione peroxidase-1, associated with increased interleukin-6 and transforming growth factor-β in the astrocyte media, when treated with plasma from MVE-exposed groups. Our results indicate that inhalation exposure to traffic-generated pollutants results in altered BBB integrity, mediated through Ang II-AT1 signaling and inflammation, which is exacerbated by an HF diet.
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Affiliation(s)
- Usa Suwannasual
- Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76201
| | - JoAnn Lucero
- Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76201
| | - Griffith Davis
- Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76201
| | - Jacob D McDonald
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico 87108
| | - Amie K Lund
- Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76201
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Damseh R, Pouliot P, Gagnon L, Sakadzic S, Boas D, Cheriet F, Lesage F. Automatic Graph-Based Modeling of Brain Microvessels Captured With Two-Photon Microscopy. IEEE J Biomed Health Inform 2019; 23:2551-2562. [PMID: 30507542 PMCID: PMC6546554 DOI: 10.1109/jbhi.2018.2884678] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Graph models of cerebral vasculature derived from two-photon microscopy have shown to be relevant to study brain microphysiology. Automatic graphing of these microvessels remain problematic due to the vascular network complexity and two-photon sensitivity limitations with depth. In this paper, we propose a fully automatic processing pipeline to address this issue. The modeling scheme consists of a fully-convolution neural network to segment microvessels, a three-dimensional surface model generator, and a geometry contraction algorithm to produce graphical models with a single connected component. Based on a quantitative assessment using NetMets metrics, at a tolerance of 60 μm, false negative and false positive geometric error 19 rates are 3.8% and 4.2%, respectively, whereas false nega- 20 tive and false positive topological error rates are 6.1% and 4.5%, respectively. Our qualitative evaluation confirms the efficiency of our scheme in generating useful and accurate graphical models.
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Affiliation(s)
- Rafat Damseh
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, QC, Canada
| | - Philippe Pouliot
- Department of Electrical Engineering, École Polytechnique de Montréal, Montreal, QC, Canada
- Research Centre, Montreal Hearth Institute, Montreal, QC, Canada
| | - Louis Gagnon
- Physics Department, Université Laval, Quebec, QC, Canada
| | - Sava Sakadzic
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - David Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Farida Cheriet
- Department of Computer and Software Engineering, École Polytechnique de Montréal, Montreal, QC, Canada
| | - Frederic Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, QC, Canada
- Department of Electrical Engineering, École Polytechnique de Montréal, Montreal, QC, Canada
- Research Centre, Montreal Hearth Institute, Montreal, QC, Canada
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6
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Yau PL, Ross N, Tirsi A, Arif A, Ozinci Z, Convit A. Insulin Sensitivity and Inflammation Mediate the Impact of Fitness on Cerebrovascular Health in Adolescents. Child Obes 2017; 13:205-212. [PMID: 28092457 PMCID: PMC5444422 DOI: 10.1089/chi.2016.0266] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND/OBJECTIVES To investigate in adolescents the relationships between retinal vessel diameter, physical fitness, insulin sensitivity, and systemic inflammation. METHODS We evaluated 157 adolescents, 112 with excessive weight and 45 lean, all without type 2 diabetes mellitus. All received detailed evaluations, including measurements of retinal vessel diameter, insulin sensitivity, levels of inflammation, and physical fitness. RESULTS Overweight/obese adolescents had significantly narrower retinal arteriolar and wider venular diameters, significantly lower insulin sensitivity, and physical fitness. They also had decreased levels of anti-inflammatory and increased levels of proinflammatory markers as well as an overall higher inflammation balance score. Fitness was associated with larger retinal arteriolar and narrower venular diameters and these relationships were mediated by insulin sensitivity. We demonstrate that inflammation also mediates the relationship between fitness and retinal venular, but not arterial diameter; insulin sensitivity and inflammation balance score jointly mediate this relationship with little overlap in their effects. CONCLUSIONS Increasing fitness and insulin sensitivity and reducing inflammation among adolescents carrying excess weight may improve microvascular integrity. Interventions to improve physical fitness and insulin function and reduce inflammation in adolescents, a group likely to benefit from such interventions, may reduce not only cardiovascular disease in middle age, but also improve cerebrovascular function later in life.
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Affiliation(s)
- Po Lai Yau
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Naima Ross
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Andrew Tirsi
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Arslan Arif
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Zeynep Ozinci
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Antonio Convit
- Department of Psychiatry, New York University School of Medicine, New York, NY.,Department of Medicine, New York University School of Medicine, New York, NY.,Department of Radiology, New York University School of Medicine, New York, NY.,Nathan Kline Institute for Psychiatric Research, Orangeburg, NY
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Abstract
The Alzheimer's disease (AD) epidemic proceeds unabated. Estimates suggest 5.4 million Americans and 36 million people worldwide have AD. No single mechanism or pathologic mediator can account for AD progression. Currently no disease modifying therapies are available. There is a large literature documenting an association among cardiovascular risk factors (CVRFs), especially diabetes and hypoxia, with increased AD incidence. CVRFs directly impair vascular function and could mediate cerebrovascular dysfunction in AD. This is important as cerebrovascular dysfunction precedes cognitive decline and onset of neurodegenerative changes in AD and AD animal models. In this review we present evidence that thrombin may be a heretofore unexplored target for AD therapy. This idea is based on the following observations. Thrombin is elevated in the brain and cerebral microvasculature in AD, is directly neurotoxic, and causes pro-inflammatory effects in endothelial cells, microglia, and astrocytes. Diabetes- and hypoxia-induced cerebrovascular effects are mediated by thrombin. Thrombin inhibitors block the effects of hypoxia on brain endothelial cells and reduce vascular inflammation in transgenic AD mice. Based on reports that reducing cerebrovascular expression of inflammatory proteins in AD mice is associated with improved cognition, we propose thrombin inhibitors could prove useful for improving cognition in AD patients. The next generation of AD therapeutics should not focus on single target drugs but rather employ a multi-component cocktail approach. We propose thrombin inhibitors be considered as potential contributors to the dementia therapy pharmacopeia. The urgent need for disease-modifying drugs in AD demands new thinking about disease pathogenesis and exploration of novel drug targets.
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Affiliation(s)
- Paula Grammas
- Texas Alzheimer's Research and Care Consortium, Austin, TX, USA Garrison Institute on Aging, Texas Tech Health Sciences Center, Lubbock, TX, USA Department of Neurology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Joseph M Martinez
- Garrison Institute on Aging, Texas Tech Health Sciences Center, Lubbock, TX, USA
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8
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Altmann JB, Yan G, Meeks JF, Abood ME, Brailoiu E, Brailoiu GC. G protein-coupled estrogen receptor-mediated effects on cytosolic calcium and nanomechanics in brain microvascular endothelial cells. J Neurochem 2015; 133:629-39. [PMID: 25703621 DOI: 10.1111/jnc.13066] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 01/28/2015] [Accepted: 02/04/2015] [Indexed: 01/14/2023]
Abstract
G protein-coupled estrogen receptor (GPER) is a relatively recently identified non-nuclear estrogen receptor, expressed in several tissues, including brain and blood vessels. The mechanisms elicited by GPER activation in brain microvascular endothelial cells are incompletely understood. The purpose of this work was to assess the effects of GPER activation on cytosolic Ca(2+) concentration, [Ca(2+)](i), nitric oxide production, membrane potential and cell nanomechanics in rat brain microvascular endothelial cells (RBMVEC). Extracellular but not intracellular administration of G-1, a selective GPER agonist, or extracellular administration of 17-β-estradiol and tamoxifen, increased [Ca(2+)](i) in RBMVEC. The effect of G-1 on [Ca(2+)](i) was abolished in Ca(2+) -free saline or in the presence of a L-type Ca(2+) channel blocker. G-1 increased nitric oxide production in RBMVEC; the effect was prevented by NG-nitro-l-arginine methyl ester. G-1 elicited membrane hyperpolarization that was abolished by the antagonists of small and intermediate-conductance Ca(2+) -activated K(+) channels, apamin, and charibdotoxin. GPER-mediated responses were sensitive to G-36, a GPER antagonist. In addition, atomic force microscopy studies revealed that G-1 increased the modulus of elasticity, indicative of cytoskeletal changes and increase in RBMVEC stiffness. Our results unravel the mechanisms underlying GPER-mediated effects in RBMVEC with implications for the effect of estrogen on cerebral microvasculature. Activation of the G protein-coupled estrogen receptor (GPER) in rat brain microvascular endothelial cells (RBMVEC) increases [Ca(2+)](i) by promoting Ca(2+) influx. The increase in [Ca(2+)](i) leads to membrane hyperpolarization, nitric oxide (NO) production, and to cytoskeletal changes and increased cell stiffness. Our results unravel the mechanisms underlying GPER-mediated effects in RBMVEC with implications for the effect of estrogen on cerebral microvasculature.
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Affiliation(s)
- Joseph B Altmann
- Department of Pharmaceutical Sciences, Thomas Jefferson University, Jefferson School of Pharmacy, Philadelphia, Pennsylvania, USA
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MacCormick IJC, Beare NAV, Taylor TE, Barrera V, White VA, Hiscott P, Molyneux ME, Dhillon B, Harding SP. Cerebral malaria in children: using the retina to study the brain. ACTA ACUST UNITED AC 2014; 137:2119-42. [PMID: 24578549 PMCID: PMC4107732 DOI: 10.1093/brain/awu001] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cerebral malaria is a dangerous complication of Plasmodium falciparum infection, which takes a devastating toll on children in sub-Saharan Africa. Although autopsy studies have improved understanding of cerebral malaria pathology in fatal cases, information about in vivo neurovascular pathogenesis is scarce because brain tissue is inaccessible in life. Surrogate markers may provide insight into pathogenesis and thereby facilitate clinical studies with the ultimate aim of improving the treatment and prognosis of cerebral malaria. The retina is an attractive source of potential surrogate markers for paediatric cerebral malaria because, in this condition, the retina seems to sustain microvascular damage similar to that of the brain. In paediatric cerebral malaria a combination of retinal signs correlates, in fatal cases, with the severity of brain pathology, and has diagnostic and prognostic significance. Unlike the brain, the retina is accessible to high-resolution, non-invasive imaging. We aimed to determine the extent to which paediatric malarial retinopathy reflects cerebrovascular damage by reviewing the literature to compare retinal and cerebral manifestations of retinopathy-positive paediatric cerebral malaria. We then compared retina and brain in terms of anatomical and physiological features that could help to account for similarities and differences in vascular pathology. These comparisons address the question of whether it is biologically plausible to draw conclusions about unseen cerebral vascular pathogenesis from the visible retinal vasculature in retinopathy-positive paediatric cerebral malaria. Our work addresses an important cause of death and neurodisability in sub-Saharan Africa. We critically appraise evidence for associations between retina and brain neurovasculature in health and disease, and in the process we develop new hypotheses about why these vascular beds are susceptible to sequestration of parasitized erythrocytes.
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Affiliation(s)
- Ian J C MacCormick
- 1 Malawi-Liverpool-Wellcome Trust Clinical Research Programme, PO Box 30096, Chichiri, Blantyre 3, Malawi2 University of Liverpool, Department of Eye and Vision Science, Faculty of Health & Life Sciences, University of Liverpool Room 356, 4th Floor, UCD Building, Daulby Street, Liverpool L69 3GA, UK
| | - Nicholas A V Beare
- 2 University of Liverpool, Department of Eye and Vision Science, Faculty of Health & Life Sciences, University of Liverpool Room 356, 4th Floor, UCD Building, Daulby Street, Liverpool L69 3GA, UK3 Royal Liverpool University Hospital, St. Paul's Eye Unit, Prescot St, Liverpool, Merseyside L7 8XP, UK
| | - Terrie E Taylor
- 5 Blantyre Malaria Project, Blantyre, Malawi6 Michigan State University, Department of Osteopathic Medical Specialities, West Fee Hall, 909 Fee Road, Room B305, East Lansing, MI 48824, USA
| | - Valentina Barrera
- 2 University of Liverpool, Department of Eye and Vision Science, Faculty of Health & Life Sciences, University of Liverpool Room 356, 4th Floor, UCD Building, Daulby Street, Liverpool L69 3GA, UK
| | - Valerie A White
- 7 Vancouver General Hospital, Department of Pathology and Laboratory Medicine, Vancouver, B.C. V5Z1M9, Canada
| | - Paul Hiscott
- 2 University of Liverpool, Department of Eye and Vision Science, Faculty of Health & Life Sciences, University of Liverpool Room 356, 4th Floor, UCD Building, Daulby Street, Liverpool L69 3GA, UK
| | - Malcolm E Molyneux
- 1 Malawi-Liverpool-Wellcome Trust Clinical Research Programme, PO Box 30096, Chichiri, Blantyre 3, Malawi4 University of Malawi College of Medicine, College of Medicine, P/Bag 360 Chichiri, Blantyre 3 Malawi8 Liverpool School of Tropical Medicine, Liverpool School of Tropical Medicine, Pembroke Place , Liverpool, L3 5QA , UK
| | - Baljean Dhillon
- 9 University of Edinburgh, Department of Ophthalmology, Edinburgh, UK10 Princess Alexandra Eye Pavilion, Edinburgh, UK
| | - Simon P Harding
- 2 University of Liverpool, Department of Eye and Vision Science, Faculty of Health & Life Sciences, University of Liverpool Room 356, 4th Floor, UCD Building, Daulby Street, Liverpool L69 3GA, UK3 Royal Liverpool University Hospital, St. Paul's Eye Unit, Prescot St, Liverpool, Merseyside L7 8XP, UK
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Zhou XM, Zhang X, Zhang XS, Zhuang Z, Li W, Sun Q, Li T, Wang CX, Zhu L, Shi JX, Zhou ML. SIRT1 inhibition by sirtinol aggravates brain edema after experimental subarachnoid hemorrhage. J Neurosci Res 2014; 92:714-22. [PMID: 24482345 DOI: 10.1002/jnr.23359] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 12/01/2013] [Accepted: 12/11/2013] [Indexed: 11/11/2022]
Abstract
Secondary brain injury following subarachnoid hemorrhage (SAH) is poorly understood. We utilized a rat model of SAH to investigate whether SIRT1 has a protective role against brain edema via the tumor suppressor protein p53 pathway. Experimental SAH was induced in adult male Sprague-Dawley rats by prechiasmatic cistern injection. Brain SIRT1 protein levels were examined in the sham controls and in rats 6, 12, 24, 48, and 72 hr after SAH induction. The SIRT1 inhibitor sirtinol was administered by intracerebroventricular infusion. Neurological functions, blood-brain barrier (BBB) disruption, and brain water content were assessed. Endothelial cell apoptosis, caspase 3 protein expression, p53 acetylation, and matrix metalloproteinase-9 (MMP-9) activity were examined. Compared with the control, SIRT1 protein expression increased remarkably, reaching a maximum at 24 hr after SAH. Sirtinol treatment significantly lowered SIRT1 expression, accompanied by deteriorated neurologic function, BBB disruption, brain edema, increased endothelial cell apoptosis, and increased MMP-9 gelatinase activity compared with the rats treated with vehicle only. Our results suggest that increased expression of endogenous SIRT1 may play a neuroprotective role against brain edema after SAH.
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Affiliation(s)
- Xiao-Ming Zhou
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Second Military Medical University, Shanghai, China
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11
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Rodrigues SF, Vital SA, Granger DN. Mild hypercholesterolemia blunts the proinflammatory and prothrombotic effects of hypertension on the cerebral microcirculation. J Cereb Blood Flow Metab 2013; 33:483-9. [PMID: 23281427 DOI: 10.1038/jcbfm.2012.194] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Although an increased leukocyte and platelet adhesion is observed in cerebral venules of mice with either hypertension (HTN) or hypercholesterolemia (HCh), it remains unclear whether the combination of HTN and HCh exerts a comparable effect on leukocyte and platelet recruitment in the cerebral microvasculature. Thus, we examined whether HCh alters platelet and leukocyte adhesion, and blood-brain barrier (BBB) permeability, in cerebral venules in two models of murine HTN: DOCA salt-induced and angiotensin II (Ang II) induced. In both models, the mice were placed on either a normal or cholesterol-enriched diet. An enhanced recruitment of adherent leukocytes and platelets in cerebral venules was noted in both HTN models in the absence of HCh, but not in its presence. The Ang II-induced increase in BBB permeability was attenuated by HCh as well. Both total and high-density lipoprotein (HDL) cholesterol levels were elevated in the HCh mice. The HTN-induced increase in leukocyte and platelet adhesion was attenuated in apolipoprotein A-I transgenic mice (ApoA1-Tg) and blunted in wild-type mice treated with the ApoA1 mimetic peptide, 4F. Our findings indicate that mild HCh significantly blunts the cerebral microvascular responses to HTN and that HDL may have a role in mediating this beneficial effect of HCh.
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