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Myburgh-Jacobsz CE, Botha-Le Roux S, Kotliar K, Wentzel A, Jacobs A, De Boever P, Goswami N, Strijdom H, Smith W. Retinal Vessel Functional Responses in South Africans Living With and Without HIV: The EndoAfrica-NWU Study. Microcirculation 2024:e12878. [PMID: 39106121 DOI: 10.1111/micc.12878] [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: 08/27/2023] [Revised: 07/05/2024] [Accepted: 07/17/2024] [Indexed: 08/09/2024]
Abstract
OBJECTIVES The effects of HIV and antiretroviral therapy (ART) on microvascular function are poorly explored. We compared retinal vessel functional responses to flicker light-induced provocation (FLIP) in people living with HIV (PLWH) and people living without HIV (PLWoutH). METHODS We included 115 PLWH and 51 PLWoutH with a median age of 41 years. Treated PLWH received similar first-line fixed-dose combination ART. Clinical characteristics and retinal vessels functional responses to FLIP were compared in (a) PLWH and PLWoutH; and (b) PLWH groups stratified by the median of (i) CD4-count (511 cells/mm3), (ii) viral load (50 copies/mL), and (iii) ART duration (57.6 months). RESULTS PLWH were older, smoked more, and had a lower prevalence of hypertension than PLWoutH (p < 0.05). Almost 64% of PLWH were infected for more than 5 years. Retinal vessel responses to FLIP were similar between PLWH and PLWoutH after taking confounders into account. In addition, PLWH subgroups stratified according to immuno-virological status by CD4-count, viral load, and ART duration showed no differences in retinal vessel responses to FLIP. CONCLUSION Living with HIV and receiving ART were not associated with altered microvascular function as assessed with dynamic retinal vessel analysis in a South African case-control study.
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Affiliation(s)
| | - Shani Botha-Le Roux
- Hypertension in Africa Research Team (HART), Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
- MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, Aachen University of Applied Sciences, Juelich, Germany
| | - Annemarie Wentzel
- Hypertension in Africa Research Team (HART), Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
- MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Adriaan Jacobs
- Hypertension in Africa Research Team (HART), Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
- MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Patrick De Boever
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
- Antwerp University Hospital (UZA), Edegem, Belgium
| | - Nandu Goswami
- Gravitational Physiology and Medicine Research Unit, Division of Physiology and Pathophysiology, Medical University of Graz, Graz, Austria
- Center for Space and Aviation Health, College of Medicine, Mohammed bin Rashid University of Medicine and Health Sciences, Dubai, UAE
| | - Hans Strijdom
- Centre for Cardio-Metabolic Research in Africa, Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
- MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
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2
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Gaire BP, Koronyo Y, Fuchs DT, Shi H, Rentsendorj A, Danziger R, Vit JP, Mirzaei N, Doustar J, Sheyn J, Hampel H, Vergallo A, Davis MR, Jallow O, Baldacci F, Verdooner SR, Barron E, Mirzaei M, Gupta VK, Graham SL, Tayebi M, Carare RO, Sadun AA, Miller CA, Dumitrascu OM, Lahiri S, Gao L, Black KL, Koronyo-Hamaoui M. Alzheimer's disease pathophysiology in the Retina. Prog Retin Eye Res 2024; 101:101273. [PMID: 38759947 PMCID: PMC11285518 DOI: 10.1016/j.preteyeres.2024.101273] [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: 02/11/2023] [Revised: 04/23/2024] [Accepted: 05/10/2024] [Indexed: 05/19/2024]
Abstract
The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of AD, including amyloid β-protein (Aβ) deposits and abnormal tau protein isoforms, in the retinas of AD patients and animal models. Moreover, structural and functional vascular abnormalities such as reduced blood flow, vascular Aβ deposition, and blood-retinal barrier damage, along with inflammation and neurodegeneration, have been described in retinas of patients with mild cognitive impairment and AD dementia. Histological, biochemical, and clinical studies have demonstrated that the nature and severity of AD pathologies in the retina and brain correspond. Proteomics analysis revealed a similar pattern of dysregulated proteins and biological pathways in the retina and brain of AD patients, with enhanced inflammatory and neurodegenerative processes, impaired oxidative-phosphorylation, and mitochondrial dysfunction. Notably, investigational imaging technologies can now detect AD-specific amyloid deposits, as well as vasculopathy and neurodegeneration in the retina of living AD patients, suggesting alterations at different disease stages and links to brain pathology. Current and exploratory ophthalmic imaging modalities, such as optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy, and hyperspectral imaging, may offer promise in the clinical assessment of AD. However, further research is needed to deepen our understanding of AD's impact on the retina and its progression. To advance this field, future studies require replication in larger and diverse cohorts with confirmed AD biomarkers and standardized retinal imaging techniques. This will validate potential retinal biomarkers for AD, aiding in early screening and monitoring.
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Affiliation(s)
- 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
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Haoshen Shi
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Altan Rentsendorj
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ron Danziger
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jean-Philippe Vit
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Nazanin Mirzaei
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jonah Doustar
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Julia Sheyn
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Harald Hampel
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Andrea Vergallo
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Miyah R Davis
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ousman Jallow
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Filippo Baldacci
- Sorbonne University, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Paris, France; Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | | | - Ernesto Barron
- Department of Ophthalmology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Mehdi Mirzaei
- Department of Clinical Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Vivek K Gupta
- Department of Clinical Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia
| | - Stuart L Graham
- Department of Clinical Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW, Australia; Department of Clinical Medicine, Macquarie University, Sydney, NSW, Australia
| | - Mourad Tayebi
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Roxana O Carare
- Department of Clinical Neuroanatomy, University of Southampton, Southampton, UK
| | - Alfredo A Sadun
- Department of Ophthalmology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Carol A Miller
- Department of Pathology Program in Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Shouri Lahiri
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Liang Gao
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Keith L Black
- 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 Neurology, 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.
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3
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Günthner R, Lorenz G, Braunisch MC, Angermann S, Matschkal J, Hausinger R, Kuchler T, Glaser P, Schicktanz F, Haller B, Heemann U, Streese L, Hanssen H, Kotliar K, Schmaderer C. Endothelial dysfunction in retinal vessels of hemodialysis patients compared to healthy controls. Sci Rep 2024; 14:13948. [PMID: 38886448 PMCID: PMC11183144 DOI: 10.1038/s41598-024-64581-9] [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: 11/30/2023] [Accepted: 06/11/2024] [Indexed: 06/20/2024] Open
Abstract
Endothelial dysfunction is a key factor promoting atherosclerosis and cardiovascular complications. Hemodialysis patients typically show various cardiovascular complications and impaired retinal venular dilation has been described as a risk factor for mortality. Non-invasive retinal vessel analysis provides insight into the microvasculature and endothelial function. Static retinal vessel analysis determines arteriolar and venular vessel diameters and dynamic retinal vessel analysis measures microvascular function by flicker-light induced stimulation, which results in physiological dilation of retinal vessels. We measured 220 healthy individuals and compared them to our preexisting cohort of hemodialysis patients (275 for static and 214 for dynamic analysis). Regarding static vessel diameters, hemodialysis patients and healthy individuals did not significantly differ between vessel diameters. Dynamic retinal vessel analysis showed attenuated dilation of the arteriole of hemodialysis patients with 1.6% vs 2.3% in healthy individuals (p = 0.009). Case-control matching for age (mean 65.4 years) did not relevantly diminish the difference. Hemodialysis patients also exhibited reduced venular dilation after matching for age (3.2% vs 3.8%, p = 0.019). Hemodialysis patients showed microvascular dysfunction compared to healthy individuals when using dynamic retinal vessel analysis. Further studies should focus on dynamic retinal vessel analysis which can add insights into the microvascular function and risk factors in multimorbid patients.
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Affiliation(s)
- Roman Günthner
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
| | - Georg Lorenz
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Matthias Christoph Braunisch
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Susanne Angermann
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Julia Matschkal
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Renate Hausinger
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Timon Kuchler
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Patrizia Glaser
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Felix Schicktanz
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Bernhard Haller
- School of Medicine, Klinikum Rechts der Isar, Institute of AI and Informatics in Medicine, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
| | - Uwe Heemann
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Lukas Streese
- Preventive Sports Medicine and Systems Physiology, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
- Faculty of Health Care, Niederrhein University of Applied Sciences, Krefeld, Germany
| | - Henner Hanssen
- Preventive Sports Medicine and Systems Physiology, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Konstantin Kotliar
- Aachen University of Applied Sciences, Heinrich-Mussmann-Str. 1, 52428, Jülich, Germany
| | - Christoph Schmaderer
- Department of Nephrology, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
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4
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Berkowitz BA, Paruchuri A, Stanek J, Abdul-Nabi M, Podolsky RH, Bustos AH, Childers KL, Murphy GG, Stangis K, Roberts R. Biomarker evidence of early vision and rod energy-linked pathophysiology benefits from very low dose DMSO in 5xFAD mice. Acta Neuropathol Commun 2024; 12:85. [PMID: 38822433 PMCID: PMC11140992 DOI: 10.1186/s40478-024-01799-8] [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: 03/04/2024] [Accepted: 05/20/2024] [Indexed: 06/03/2024] Open
Abstract
Here, we test whether early visual and OCT rod energy-linked biomarkers indicating pathophysiology in nicotinamide nucleotide transhydrogenase (Nnt)-null 5xFAD mice also occur in Nnt-intact 5xFAD mice and whether these biomarkers can be pharmacologically treated. Four-month-old wild-type or 5xFAD C57BL/6 substrains with either a null (B6J) Nnt or intact Nnt gene (B6NTac) and 5xFAD B6J mice treated for one month with either R-carvedilol + vehicle or only vehicle (0.01% DMSO) were studied. The contrast sensitivity (CS), external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness (a proxy for low pH-triggered water removal), profile shape of the hyperreflective band just posterior to the ELM (i.e., the mitochondrial configuration within photoreceptors per aspect ratio [MCP/AR]), and retinal laminar thickness were measured. Both wild-type substrains showed similar visual performance indices and dark-evoked ELM-RPE contraction. The lack of a light-dark change in B6NTac MCP/AR, unlike in B6J mice, is consistent with relatively greater mitochondrial efficiency. 5xFAD B6J mice, but not 5xFAD B6NTac mice, showed lower-than-WT CS. Light-adapted 5xFAD substrains both showed abnormal ELM-RPE contraction and greater-than-WT MCP/AR contraction. The inner retina and superior outer retina were thinner. Treating 5xFAD B6J mice with R-carvedilol + DMSO or DMSO alone corrected CS and ELM-RPE contraction but not supernormal MCP/AR contraction or laminar thinning. These results provide biomarker evidence for prodromal photoreceptor mitochondrial dysfunction/oxidative stress/oxidative damage, which is unrelated to visual performance, as well as the presence of the Nnt gene. This pathophysiology is druggable in 5xFAD mice.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA.
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Mura Abdul-Nabi
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, MD, USA
| | | | | | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology, Molecular Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Katherine Stangis
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
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5
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Owens CD, Bonin Pinto C, Detwiler S, Olay L, Pinaffi-Langley ACDC, Mukli P, Peterfi A, Szarvas Z, James JA, Galvan V, Tarantini S, Csiszar A, Ungvari Z, Kirkpatrick AC, Prodan CI, Yabluchanskiy A. Neurovascular coupling impairment as a mechanism for cognitive deficits in COVID-19. Brain Commun 2024; 6:fcae080. [PMID: 38495306 PMCID: PMC10943572 DOI: 10.1093/braincomms/fcae080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/08/2024] [Accepted: 03/05/2024] [Indexed: 03/19/2024] Open
Abstract
Components that comprise our brain parenchymal and cerebrovascular structures provide a homeostatic environment for proper neuronal function to ensure normal cognition. Cerebral insults (e.g. ischaemia, microbleeds and infection) alter cellular structures and physiologic processes within the neurovascular unit and contribute to cognitive dysfunction. COVID-19 has posed significant complications during acute and convalescent stages in multiple organ systems, including the brain. Cognitive impairment is a prevalent complication in COVID-19 patients, irrespective of severity of acute SARS-CoV-2 infection. Moreover, overwhelming evidence from in vitro, preclinical and clinical studies has reported SARS-CoV-2-induced pathologies in components of the neurovascular unit that are associated with cognitive impairment. Neurovascular unit disruption alters the neurovascular coupling response, a critical mechanism that regulates cerebromicrovascular blood flow to meet the energetic demands of locally active neurons. Normal cognitive processing is achieved through the neurovascular coupling response and involves the coordinated action of brain parenchymal cells (i.e. neurons and glia) and cerebrovascular cell types (i.e. endothelia, smooth muscle cells and pericytes). However, current work on COVID-19-induced cognitive impairment has yet to investigate disruption of neurovascular coupling as a causal factor. Hence, in this review, we aim to describe SARS-CoV-2's effects on the neurovascular unit and how they can impact neurovascular coupling and contribute to cognitive decline in acute and convalescent stages of the disease. Additionally, we explore potential therapeutic interventions to mitigate COVID-19-induced cognitive impairment. Given the great impact of cognitive impairment associated with COVID-19 on both individuals and public health, the necessity for a coordinated effort from fundamental scientific research to clinical application becomes imperative. This integrated endeavour is crucial for mitigating the cognitive deficits induced by COVID-19 and its subsequent burden in this especially vulnerable population.
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Affiliation(s)
- Cameron D Owens
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Camila Bonin Pinto
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Sam Detwiler
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Lauren Olay
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Ana Clara da C Pinaffi-Langley
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Peter Mukli
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Anna Peterfi
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Zsofia Szarvas
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Judith A James
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Arthritis & Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Veronica Galvan
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Stefano Tarantini
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Anna Csiszar
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
| | - Zoltan Ungvari
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Angelia C Kirkpatrick
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Cardiovascular Section, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Calin I Prodan
- Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
- Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Andriy Yabluchanskiy
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Vascular Cognitive Impairment, Neurodegeneration and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Departments of Public Health, Translational Medicine and Physiology, Semmelweis University, Budapest, 1089, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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6
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Mujat M, Sampani K, Patel AH, Zambrano R, Sun JK, Wollstein G, Ferguson RD, Schuman JS, Iftimia N. Motion Contrast, Phase Gradient, and Simultaneous OCT Images Assist in the Interpretation of Dark-Field Images in Eyes with Retinal Pathology. Diagnostics (Basel) 2024; 14:184. [PMID: 38248061 PMCID: PMC10814023 DOI: 10.3390/diagnostics14020184] [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: 12/02/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/23/2024] Open
Abstract
The cellular-level visualization of retinal microstructures such as blood vessel wall components, not available with other imaging modalities, is provided with unprecedented details by dark-field imaging configurations; however, the interpretation of such images alone is sometimes difficult since multiple structural disturbances may be present in the same time. Particularly in eyes with retinal pathology, microstructures may appear in high-resolution retinal images with a wide range of sizes, sharpnesses, and brightnesses. In this paper we show that motion contrast and phase gradient imaging modalities, as well as the simultaneous acquisition of depth-resolved optical coherence tomography (OCT) images, provide additional insight to help understand the retinal neural and vascular structures seen in dark-field images and may enable improved diagnostic and treatment plans.
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Affiliation(s)
- Mircea Mujat
- Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810, USA; (A.H.P.); (R.D.F.); (N.I.)
| | - Konstantina Sampani
- Beetham Eye Institute, Joslin Diabetes Center, Boston, MA 02115, USA; (K.S.); (J.K.S.)
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Ankit H. Patel
- Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810, USA; (A.H.P.); (R.D.F.); (N.I.)
| | - Ronald Zambrano
- Department of Ophthalmology, New York University School of Medicine, New York, NY 10017, USA; (R.Z.); (G.W.)
| | - Jennifer K. Sun
- Beetham Eye Institute, Joslin Diabetes Center, Boston, MA 02115, USA; (K.S.); (J.K.S.)
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
| | - Gadi Wollstein
- Department of Ophthalmology, New York University School of Medicine, New York, NY 10017, USA; (R.Z.); (G.W.)
| | - R. Daniel Ferguson
- Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810, USA; (A.H.P.); (R.D.F.); (N.I.)
| | | | - Nicusor Iftimia
- Physical Sciences, Inc., 20 New England Business Center, Andover, MA 01810, USA; (A.H.P.); (R.D.F.); (N.I.)
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7
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Danielescu C, Dabija MG, Nedelcu AH, Lupu VV, Lupu A, Ioniuc I, Gîlcă-Blanariu GE, Donica VC, Anton ML, Musat O. Automated Retinal Vessel Analysis Based on Fundus Photographs as a Predictor for Non-Ophthalmic Diseases-Evolution and Perspectives. J Pers Med 2023; 14:45. [PMID: 38248746 PMCID: PMC10817503 DOI: 10.3390/jpm14010045] [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: 11/28/2023] [Revised: 12/27/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024] Open
Abstract
The study of retinal vessels in relation to cardiovascular risk has a long history. The advent of a dedicated tool based on digital imaging, i.e., the retinal vessel analyzer, and also other software such as Integrative Vessel Analysis (IVAN), Singapore I Vessel Assessment (SIVA), and Vascular Assessment and Measurement Platform for Images of the Retina (VAMPIRE), has led to the accumulation of a formidable body of evidence regarding the prognostic value of retinal vessel analysis (RVA) for cardiovascular and cerebrovascular disease (including arterial hypertension in children). There is also the potential to monitor the response of retinal vessels to therapies such as physical activity or bariatric surgery. The dynamic vessel analyzer (DVA) remains a unique way of studying neurovascular coupling, helping to understand the pathogenesis of cerebrovascular and neurodegenerative conditions and also being complementary to techniques that measure macrovascular dysfunction. Beyond cardiovascular disease, retinal vessel analysis has shown associations with and prognostic value for neurological conditions, inflammation, kidney function, and respiratory disease. Artificial intelligence (AI) (represented by algorithms such as QUantitative Analysis of Retinal vessel Topology and siZe (QUARTZ), SIVA-DLS (SIVA-deep learning system), and many others) seems efficient in extracting information from fundus photographs, providing prognoses of various general conditions with unprecedented predictive value. The future challenges will be integrating RVA and other qualitative and quantitative risk factors in a unique, comprehensive prediction tool, certainly powered by AI, while building the much-needed acceptance for such an approach inside the medical community and reducing the "black box" effect, possibly by means of saliency maps.
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Affiliation(s)
- Ciprian Danielescu
- Department of Ophthalmology, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania;
| | - Marius Gabriel Dabija
- Department of Surgery II, Discipline of Neurosurgery, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania;
| | - Alin Horatiu Nedelcu
- Department of Morpho-Functional Sciences I, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania;
| | - Vasile Valeriu Lupu
- Department of Pediatrics, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania; (V.V.L.); (I.I.)
| | - Ancuta Lupu
- Department of Pediatrics, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania; (V.V.L.); (I.I.)
| | - Ileana Ioniuc
- Department of Pediatrics, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania; (V.V.L.); (I.I.)
| | | | - Vlad-Constantin Donica
- Doctoral School, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania; (V.-C.D.); (M.-L.A.)
| | - Maria-Luciana Anton
- Doctoral School, University of Medicine and Pharmacy “Grigore T. Popa”, 700115 Iasi, Romania; (V.-C.D.); (M.-L.A.)
| | - Ovidiu Musat
- Department of Ophthalmology, University of Medicine and Pharmacy “Carol Davila”, 020021 Bucuresti, Romania;
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8
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Pian Q, Alfadhel M, Tang J, Lee GV, Li B, Fu B, Ayata Y, Yaseen MA, Boas DA, Secomb TW, Sakadzic S. Cortical microvascular blood flow velocity mapping by combining dynamic light scattering optical coherence tomography and two-photon microscopy. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:076003. [PMID: 37484973 PMCID: PMC10362155 DOI: 10.1117/1.jbo.28.7.076003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 07/25/2023]
Abstract
Significance The accurate large-scale mapping of cerebral microvascular blood flow velocity is crucial for a better understanding of cerebral blood flow (CBF) regulation. Although optical imaging techniques enable both high-resolution microvascular angiography and fast absolute CBF velocity measurements in the mouse cortex, they usually require different imaging techniques with independent system configurations to maximize their performances. Consequently, it is still a challenge to accurately combine functional and morphological measurements to co-register CBF speed distribution from hundreds of microvessels with high-resolution microvascular angiograms. Aim We propose a data acquisition and processing framework to co-register a large set of microvascular blood flow velocity measurements from dynamic light scattering optical coherence tomography (DLS-OCT) with the corresponding microvascular angiogram obtained using two-photon microscopy (2PM). Approach We used DLS-OCT to first rapidly acquire a large set of microvascular velocities through a sealed cranial window in mice and then to acquire high-resolution microvascular angiograms using 2PM. The acquired data were processed in three steps: (i) 2PM angiogram coregistration with the DLS-OCT angiogram, (ii) 2PM angiogram segmentation and graphing, and (iii) mapping of the CBF velocities to the graph representation of the 2PM angiogram. Results We implemented the developed framework on the three datasets acquired from the mice cortices to facilitate the coregistration of the large sets of DLS-OCT flow velocity measurements with 2PM angiograms. We retrieved the distributions of red blood cell velocities in arterioles, venules, and capillaries as a function of the branching order from precapillary arterioles and postcapillary venules from more than 1000 microvascular segments. Conclusions The proposed framework may serve as a useful tool for quantitative analysis of large microvascular datasets obtained by OCT and 2PM in studies involving normal brain functioning, progression of various diseases, and numerical modeling of the oxygen advection and diffusion in the realistic microvascular networks.
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Affiliation(s)
- Qi Pian
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Mohammed Alfadhel
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Northeastern University, Department of Bioengineering, Boston, Massachusetts, United States
| | - Jianbo Tang
- Southern University of Science and Technology, Department of Biomedical Engineering, Shenzhen, China
| | - Grace V. Lee
- University of Arizona, Program in Applied Mathematics, Tucson, Arizona, United States
| | - Baoqiang Li
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Brain Cognition and Brain Disease Institute; Shenzhen Fundamental Research Institutions, Shenzhen–Hong Kong Institute of Brain Science, Shenzhen, Guangdong, China
| | - Buyin Fu
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Yagmur Ayata
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Mohammad Abbas Yaseen
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Northeastern University, Department of Bioengineering, Boston, Massachusetts, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Timothy W. Secomb
- University of Arizona, Program in Applied Mathematics, Tucson, Arizona, United States
- University of Arizona, Department of Mathematics, Tucson, Arizona, United States
- University of Arizona, Department of Physiology, Tucson, Arizona, United States
| | - Sava Sakadzic
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
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9
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Berkowitz BA, Podolsky RH, Childers KL, Roberts R, Waseem R. Multiple Bioenergy-Linked OCT Biomarkers Suggest Greater-Than-Normal Rod Mitochondria Activity Early in Experimental Alzheimer's Disease. Invest Ophthalmol Vis Sci 2023; 64:12. [PMID: 36867132 PMCID: PMC9988708 DOI: 10.1167/iovs.64.3.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Purpose In Alzheimer's disease, central brain neurons show evidence for early hyperactivity. It is unclear if this occurs in the retina, another disease target. Here, we tested for imaging biomarker manifestation of prodromal hyperactivity in rod mitochondria in vivo in experimental Alzheimer's disease. Methods Light- and dark-adapted 4-month-old 5xFAD and wild-type (WT) mice, both on a C57BL/6J background, were studied with optical coherence tomography (OCT). We measured the reflectivity profile shape of the inner segment ellipsoid zone (EZ) as a proxy for mitochondria distribution. Two additional indices responsive to mitochondria activity were also measured: the thickness of the external limiting membrane-retinal pigment epithelium (ELM-RPE) region and the signal magnitude of a hyporeflective band (HB) between photoreceptor tips and apical RPE. Retinal laminar thickness and visual performance were evaluated. Results In response to low energy demand (light), WT mice showed the expected elongation in EZ reflectivity profile shape, relatively thicker ELM-RPE, and greater HB signal. Under high energy demand (dark), the EZ reflectivity profile shape was rounder, the ELM-RPE was thinner, and the HB was reduced. These OCT biomarker patterns for light-adapted 5xFAD mice did not match those of light-adapted WT mice but rather that of dark-adapted WT mice. Dark-adapted 5xFAD and WT mice showed the same biomarker pattern. The 5xFAD mice exhibited modest nuclear layer thinning and lower-than-normal contrast sensitivity. Conclusions Results from three OCT bioenergy biomarkers raise the novel possibility of early rod hyperactivity in vivo in a common Alzheimer's disease model.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen L Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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10
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Sensi SL, Russo M, Tiraboschi P. Biomarkers of diagnosis, prognosis, pathogenesis, response to therapy: Convergence or divergence? Lessons from Alzheimer's disease and synucleinopathies. HANDBOOK OF CLINICAL NEUROLOGY 2023; 192:187-218. [PMID: 36796942 DOI: 10.1016/b978-0-323-85538-9.00015-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Alzheimer's disease (AD) is the most common disorder associated with cognitive impairment. Recent observations emphasize the pathogenic role of multiple factors inside and outside the central nervous system, supporting the notion that AD is a syndrome of many etiologies rather than a "heterogeneous" but ultimately unifying disease entity. Moreover, the defining pathology of amyloid and tau coexists with many others, such as α-synuclein, TDP-43, and others, as a rule, not an exception. Thus, an effort to shift our AD paradigm as an amyloidopathy must be reconsidered. Along with amyloid accumulation in its insoluble state, β-amyloid is becoming depleted in its soluble, normal states, as a result of biological, toxic, and infectious triggers, requiring a shift from convergence to divergence in our approach to neurodegeneration. These aspects are reflected-in vivo-by biomarkers, which have become increasingly strategic in dementia. Similarly, synucleinopathies are primarily characterized by abnormal deposition of misfolded α-synuclein in neurons and glial cells and, in the process, depleting the levels of the normal, soluble α-synuclein that the brain needs for many physiological functions. The soluble to insoluble conversion also affects other normal brain proteins, such as TDP-43 and tau, accumulating in their insoluble states in both AD and dementia with Lewy bodies (DLB). The two diseases have been distinguished by the differential burden and distribution of insoluble proteins, with neocortical phosphorylated tau deposition more typical of AD and neocortical α-synuclein deposition peculiar to DLB. We propose a reappraisal of the diagnostic approach to cognitive impairment from convergence (based on clinicopathologic criteria) to divergence (based on what differs across individuals affected) as a necessary step for the launch of precision medicine.
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Affiliation(s)
- Stefano L Sensi
- Department of Neuroscience, Imaging, and Clinical Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Molecular Neurology Unit, Center for Advanced Studies and Technology-CAST and ITAB Institute for Advanced Biotechnology, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.
| | - Mirella Russo
- Department of Neuroscience, Imaging, and Clinical Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Molecular Neurology Unit, Center for Advanced Studies and Technology-CAST and ITAB Institute for Advanced Biotechnology, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Pietro Tiraboschi
- Division of Neurology V-Neuropathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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11
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Faure C, Castrale C, Benabed A, Cognard P, Lezé R, Castro-Farias D, Gérard M, Louapre C, Paques M. Structural and functional analysis of retinal vasculature in HANAC syndrome with a novel intronic COL4A1 mutation. Microvasc Res 2023; 145:104450. [PMID: 36372235 DOI: 10.1016/j.mvr.2022.104450] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 10/17/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022]
Abstract
PURPOSE Mutations of the COL4A1 gene, a major structural protein of vessels, may cause hereditary angiopathy with nephropathy, aneurysms and muscle cramps (HANAC) syndrome. The vascular structure and function of patients with HANAC is poorly known. Here, we report a family with HANAC syndrome associated to a previously unreported mutation in COL4A1. The structure and function of retinal vessels were detailed by adaptive optics ophthalmoscopy (AOO) and optical coherence tomography (OCT) angiography. METHODS Clinical data from six affected individuals (43 to 72 years old) from a single family comprising two generations were collected. Imaging charts including conventional fundus imaging, OCT-angiography and AOO in static and dynamic (flicker) mode were reviewed. DNA sequencing was done in the proband. RESULTS DNA sequencing of the proband revealed a heterozygous deletion of COL4A1 (NM_001845) at position 1120 in the intron 20 resulting in the loss of splicing donor site for exon 20 (c.1120 + 2_1120 + 8del heterozygote). Four patients had arterial hypertension, and three had kidney dysfunction, one of which under dialysis. By fundus examination, five had typical retinal arteriolar tortuosity with arteriolar loops. Wall-to-lumen ratio of arteries was within normal limits, that is, lower than expected for hypertensive patients. Several foci of arteriolar irregularities were noted in the two oldest patients. In three affected subjects, evaluation of the neurovascular coupling showed a higher flicker-induced vasodilation than a control population (6 % to 11 %; n < 5 %). CONCLUSIONS Structural and dynamic analysis of retinal vessels in a HANAC family bearing a previously unreported intronic COL4 mutation was done. In addition to arteriolar tortuosity, we found reduced wall-to-lumen ratio, arteriolar irregularity and increased vasodilatory response to flicker light. These abnormalities were more marked in the oldest subjects. This abnormal flicker response affected also non-tortuous arteries, suggesting that microvascular dysfunction extends beyond tortuosity. Such explorations may help to better vascular dysfunction related to HANAC and hence better understand the mechanisms of end-organ damage.
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Affiliation(s)
- Céline Faure
- Ophthalmology department, Saint Martin hospital, Ramsay Générale de Santé, 18 rue des Roquemonts, 14000 Caen, France; Clinical Investigation Center 1423, Quinze-Vingts hospital, INSERM-DHOS, Paris F-75012, France.
| | - Cindy Castrale
- Nephrology department, Saint Martin hospital, Ramsay Générale de Santé, 18 rue des Roquemonts, 14000 Caen, France
| | - Anaïs Benabed
- Nephrology department, Saint Martin hospital, Ramsay Générale de Santé, 18 rue des Roquemonts, 14000 Caen, France
| | - Pauline Cognard
- Ophthalmology department, Saint Martin hospital, Ramsay Générale de Santé, 18 rue des Roquemonts, 14000 Caen, France
| | - Romain Lezé
- Ophthalmology department, Saint Martin hospital, Ramsay Générale de Santé, 18 rue des Roquemonts, 14000 Caen, France
| | - Daniela Castro-Farias
- Clinical Investigation Center 1423, Quinze-Vingts hospital, INSERM-DHOS, Paris F-75012, France
| | - Marion Gérard
- Genetics department, CHU de Caen-Hôpital Clémenceau, avenue Georges Clémenceau, France
| | - Céline Louapre
- Sorbonne University, APHP, Pitié-Salpêtrière Hospital, Department of neurology, CIC Neurosciences, Paris Brain Institute, Paris, France
| | - Michel Paques
- Clinical Investigation Center 1423, Quinze-Vingts hospital, INSERM-DHOS, Paris F-75012, France
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12
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Morisset C, Dizeux A, Larrat B, Selingue E, Boutin H, Picaud S, Sahel JA, Ialy-Radio N, Pezet S, Tanter M, Deffieux T. Retinal functional ultrasound imaging (rfUS) for assessing neurovascular alterations: a pilot study on a rat model of dementia. Sci Rep 2022; 12:19515. [PMID: 36376408 PMCID: PMC9663720 DOI: 10.1038/s41598-022-23366-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022] Open
Abstract
Fifty million people worldwide are affected by dementia, a heterogeneous neurodegenerative condition encompassing diseases such as Alzheimer's, vascular dementia, and Parkinson's. For them, cognitive decline is often the first marker of the pathology after irreversible brain damage has already occurred. Researchers now believe that structural and functional alterations of the brain vasculature could be early precursors of the diseases and are looking at how functional imaging could provide an early diagnosis years before irreversible clinical symptoms. In this preclinical pilot study, we proposed using functional ultrasound (fUS) on the retina to assess neurovascular alterations non-invasively, bypassing the skull limitation. We demonstrated for the first time the use of functional ultrasound in the retina and applied it to characterize the retinal hemodynamic response function in vivo in rats following a visual stimulus. We then demonstrated that retinal fUS could measure robust neurovascular coupling alterations between wild-type rats and TgF344-AD rat models of Alzheimer's disease. We observed an average relative increase in blood volume of 21% in the WT versus 37% for the TG group (p = 0.019). As a portable, non-invasive and inexpensive technique, rfUS is a promising functional screening tool in clinics for dementia years before symptoms.
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Affiliation(s)
- Clementine Morisset
- grid.440907.e0000 0004 1784 3645Institute Physics for Medicine Paris, INSERM U1273, ESPCI PSL Paris, CNRS UMR 8631, PSL Research University, Paris, France
| | - Alexandre Dizeux
- grid.440907.e0000 0004 1784 3645Institute Physics for Medicine Paris, INSERM U1273, ESPCI PSL Paris, CNRS UMR 8631, PSL Research University, Paris, France
| | - Benoit Larrat
- grid.457334.20000 0001 0667 2738NeuroSpin, Institut Des Sciences du Vivant Frédéric Joliot, Commissariat À L’Energie Atomique Et Aux Energies Alternatives (CEA), CNRS, Université Paris-Saclay, 91191 Gif-Sur-Yvette, France
| | - Erwan Selingue
- grid.457334.20000 0001 0667 2738NeuroSpin, Institut Des Sciences du Vivant Frédéric Joliot, Commissariat À L’Energie Atomique Et Aux Energies Alternatives (CEA), CNRS, Université Paris-Saclay, 91191 Gif-Sur-Yvette, France
| | - Herve Boutin
- grid.5379.80000000121662407Faculty of Biology, Medicine and Health, School of Biological Sciences Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, M13 9PL UK ,grid.5379.80000000121662407Wolfson Molecular Imaging Centre, University of Manchester, 27 Palatine Road, Manchester, M20 3LJ UK ,grid.462482.e0000 0004 0417 0074Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance and University of Manchester, Manchester, UK
| | - Serge Picaud
- grid.418241.a0000 0000 9373 1902Institut de La Vision, Sorbonne Université, INSERM, CNRS, 17 Rue Moreau, 75012 Paris, France
| | - Jose-Alain Sahel
- grid.418241.a0000 0000 9373 1902Institut de La Vision, Sorbonne Université, INSERM, CNRS, 17 Rue Moreau, 75012 Paris, France ,grid.21925.3d0000 0004 1936 9000Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA ,grid.417888.a0000 0001 2177 525XDepartment of Ophthalmology and Vitreo-Retinal Diseases, Fondation Ophtalmologique Rothschild, 75019 Paris, France
| | - Nathalie Ialy-Radio
- grid.440907.e0000 0004 1784 3645Institute Physics for Medicine Paris, INSERM U1273, ESPCI PSL Paris, CNRS UMR 8631, PSL Research University, Paris, France
| | - Sophie Pezet
- grid.440907.e0000 0004 1784 3645Institute Physics for Medicine Paris, INSERM U1273, ESPCI PSL Paris, CNRS UMR 8631, PSL Research University, Paris, France
| | - Mickael Tanter
- grid.440907.e0000 0004 1784 3645Institute Physics for Medicine Paris, INSERM U1273, ESPCI PSL Paris, CNRS UMR 8631, PSL Research University, Paris, France
| | - Thomas Deffieux
- grid.440907.e0000 0004 1784 3645Institute Physics for Medicine Paris, INSERM U1273, ESPCI PSL Paris, CNRS UMR 8631, PSL Research University, Paris, France
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13
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Altered retinal cerebral vessel oscillation frequencies in Alzheimer's disease compatible with impaired amyloid clearance. Neurobiol Aging 2022; 120:117-127. [DOI: 10.1016/j.neurobiolaging.2022.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 08/20/2022] [Accepted: 08/23/2022] [Indexed: 11/15/2022]
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14
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Hanssen H, Streese L, Vilser W. Retinal vessel diameters and function in cardiovascular risk and disease. Prog Retin Eye Res 2022; 91:101095. [PMID: 35760749 DOI: 10.1016/j.preteyeres.2022.101095] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 12/13/2022]
Abstract
In the last two decades evidence has gradually accumulated suggesting that the eye may be a unique window for cardiovascular risk stratification based on the assessment of subclinical damage of retinal microvascular structure and function. This can be facilitated by non-invasive analysis of static retinal vessel diameters and dynamic recording of flicker light-induced and endothelial function-related dilation of both retinal arterioles and venules. Recent new findings have made retinal microvascular biomarkers strong candidates for clinical implementation as reliable risk predictors. Beyond a review of the current evidence and state of research, the article aims to discuss the methodological benefits and pitfalls and to identify research gaps and future directions. Above all, the potential use for screening and treatment monitoring of cardiovascular disease risk are highlighted. The article provides fundamental comprehension of retinal vessel imaging by explaining anatomical and physiological essentials of the retinal microcirculation leading to a detailed description of the methodological approach. This allows for better understanding of the underlying retinal microvascular pathology associated with the prevalence and development of cardiovascular disease. A body of new evidence is presented on the clinical validity and predictive value of retinal vessel diameters and function for incidence cardiovascular disease and outcome. Findings in children indicate the potential for utility in childhood cardiovascular disease prevention, and the efficacy of exercise interventions highlight the treatment sensitivity of retinal microvascular biomarkers. Finally, coming from the availability of normative data, solutions for diagnostic challenges are discussed and conceptual steps towards clinical implementation are put into perspective.
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Affiliation(s)
- Henner Hanssen
- Department of Sport, Exercise and Health, Preventive Sports Medicine and Systems Physiology, Medical Faculty, University of Basel, Switzerland.
| | - Lukas Streese
- Department of Sport, Exercise and Health, Preventive Sports Medicine and Systems Physiology, Medical Faculty, University of Basel, Switzerland
| | - Walthard Vilser
- Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany; Neonatology and Pediatric Intensive Care Unit, Department of Pediatrics, Jena University Hospital, Jena, Germany
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15
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Angermann S, Günthner R, Hanssen H, Lorenz G, Braunisch MC, Steubl D, Matschkal J, Kemmner S, Hausinger R, Block Z, Haller B, Heemann U, Kotliar K, Grimmer T, Schmaderer C. Cognitive impairment and microvascular function in end-stage renal disease. Int J Methods Psychiatr Res 2022; 31:e1909. [PMID: 35290686 PMCID: PMC9159686 DOI: 10.1002/mpr.1909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Hemodialysis patients show an approximately threefold higher prevalence of cognitive impairment compared to the age-matched general population. Impaired microcirculatory function is one of the assumed causes. Dynamic retinal vessel analysis is a quantitative method for measuring neurovascular coupling and microvascular endothelial function. We hypothesize that cognitive impairment is associated with altered microcirculation of retinal vessels. METHODS 152 chronic hemodialysis patients underwent cognitive testing using the Montreal Cognitive Assessment. Retinal microcirculation was assessed by Dynamic Retinal Vessel Analysis, which carries out an examination recording retinal vessels' reaction to a flicker light stimulus under standardized conditions. RESULTS In unadjusted as well as in adjusted linear regression analyses a significant association between the visuospatial executive function domain score of the Montreal Cognitive Assessment and the maximum arteriolar dilation as response of retinal arterioles to the flicker light stimulation was obtained. CONCLUSION This is the first study determining retinal microvascular function as surrogate for cerebral microvascular function and cognition in hemodialysis patients. The relationship between impairment in executive function and reduced arteriolar reaction to flicker light stimulation supports the involvement of cerebral small vessel disease as contributing factor for the development of cognitive impairment in this patient population and might be a target for noninvasive disease monitoring and therapeutic intervention.
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Affiliation(s)
- Susanne Angermann
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Roman Günthner
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Henner Hanssen
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Georg Lorenz
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Matthias C Braunisch
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Dominik Steubl
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Julia Matschkal
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Stephan Kemmner
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany.,Transplant Center, University Hospital Munich, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Renate Hausinger
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Zenonas Block
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Bernhard Haller
- Institute of Medical Informatics, Statistics and Epidemiology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Uwe Heemann
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
| | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Campus Jülich, Jülich, Germany
| | - Timo Grimmer
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Christoph Schmaderer
- Department of Nephrology, Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Munchen, Germany
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16
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The effects of locomotion on sensory-evoked haemodynamic responses in the cortex of awake mice. Sci Rep 2022; 12:6236. [PMID: 35422473 PMCID: PMC9010417 DOI: 10.1038/s41598-022-10195-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 04/04/2022] [Indexed: 12/22/2022] Open
Abstract
Investigating neurovascular coupling in awake rodents is becoming ever more popular due, in part, to our increasing knowledge of the profound impacts that anaesthesia can have upon brain physiology. Although awake imaging brings with it many advantages, we still do not fully understand how voluntary locomotion during imaging affects sensory-evoked haemodynamic responses. In this study we investigated how evoked haemodynamic responses can be affected by the amount and timing of locomotion. Using an awake imaging set up, we used 2D-Optical Imaging Spectroscopy (2D-OIS) to measure changes in cerebral haemodynamics within the sensory cortex of the brain during either 2 s whisker stimulation or spontaneous (no whisker stimulation) experiments, whilst animals could walk on a spherical treadmill. We show that locomotion alters haemodynamic responses. The amount and timing of locomotion relative to whisker stimulation is important, and can significantly impact sensory-evoked haemodynamic responses. If locomotion occurred before or during whisker stimulation, the amplitude of the stimulus-evoked haemodynamic response was significantly altered. Therefore, monitoring of locomotion during awake imaging is necessary to ensure that conclusions based on comparisons of evoked haemodynamic responses (e.g., between control and disease groups) are not confounded by the effects of locomotion.
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17
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Tamplin MR, Broadhurst KA, Vitale AH, Hashimoto R, Kardon RH, Grumbach IM. Measuring hyperemic response to light flicker stimulus using continuous laser speckle flowgraphy in mice. Exp Eye Res 2022; 216:108952. [PMID: 35051429 PMCID: PMC9014798 DOI: 10.1016/j.exer.2022.108952] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 11/19/2022]
Abstract
Alterations in neurovascular coupling have been associated with various ocular, cerebral, and systemic vascular disorders. In the eye, changes in vessel caliber by dynamic vessel analysis have been used to measure neurovascular coupling following a light flicker stimulus. Here, we present a new protocol for quantifying light-flicker induced hyperemia in the C57/Bl6J mouse retina using laser speckle flowgraphy (LSFG). Our protocol was adapted from protocols used in human subjects. By acquiring continuous time series data, we detected significant increase in blood flow. These responses are maintained with low variability over multiple imaging sessions, indicating these methods may be applied in serial studies of neurovascular coupling.
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Affiliation(s)
- Michelle R Tamplin
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - Kimberly A Broadhurst
- Division of Cardiovascular Medicine, Abboud Cardiovascular Research Center, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Anthony H Vitale
- Division of Cardiovascular Medicine, Abboud Cardiovascular Research Center, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Ryuya Hashimoto
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
| | - Randy H Kardon
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA; Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA.
| | - Isabella M Grumbach
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA; Division of Cardiovascular Medicine, Abboud Cardiovascular Research Center, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA.
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18
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van der Heide FCT, van Sloten TT, Willekens N, Stehouwer CDA. Neurovascular coupling unit dysfunction and dementia: Retinal measurements as tools to move towards population-based evidence. Front Endocrinol (Lausanne) 2022; 13:1014287. [PMID: 36506058 PMCID: PMC9727310 DOI: 10.3389/fendo.2022.1014287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/31/2022] [Indexed: 11/24/2022] Open
Abstract
Dysfunction of the neurovascular coupling unit may be an important contributor to dementia. The neurovascular coupling unit comprises neuronal structures (e.g. astrocytes) and vascular structures (e.g. endothelial cells) that functionally interact both at the level of the arterioles as well as at the capillary level (blood-brain barrier) to regulate optimal metabolic conditions in the brain. However, it remains unclear how and to what extent dysfunction of the neurovascular coupling unit contributes to the early-stage pathobiology of dementia. Currently, limited data are available on the association between neurovascular coupling unit dysfunction, as quantified by cerebral imaging techniques, and cognitive performance. In particular, there is a lack of population-based human data (defined as studies with a sample size ~n>500). This is an important limitation because population-based studies, in comparison with smaller clinical studies, provide data which is better representative of the general population; are less susceptible to selection bias; and have a larger statistical power to detect small associations. To acquire population-based data, however, alternative imaging techniques than cerebral imaging techniques may be required. Disadvantages of cerebral imaging techniques, which limit use in population-based studies, are that these techniques are relatively expensive, time-consuming, and/or invasive. In this review, we propose that retinal imaging techniques can be used for population-based studies: on the one hand the retina and brain have many anatomical and physiological similarities; and on the other hand retinal imaging techniques are non-invasive, highly accurate, relatively inexpensive, and require relatively short measurement time. To provide support for this concept, we provide an overview on the human (population-based) evidence on the associations of retinal indices of neurodegeneration, microvascular dysfunction, and dysfunction of the neurovascular coupling unit with magnetic resonance imaging (MRI) features of structural brain abnormalities and cognitive performance.
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Affiliation(s)
- Frank C. T. van der Heide
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
- Department of Psychiatry and Neuropsychology, MUMC+, Maastricht, Netherlands
- School of Mental Health and Neuroscience, MUMC+, Maastricht, Netherlands
- *Correspondence: Frank C. T. van der Heide,
| | - Thomas T. van Sloten
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
| | - Nele Willekens
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
| | - Coen D. A. Stehouwer
- CARIM School for Cardiovascular Diseases, Maastricht University (UM), Maastricht, Netherlands
- Department of Internal Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
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19
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Abstract
In this work, we introduce a deep learning architecture for evaluation on multimodal electroencephalographic (EEG) and functional near-infrared spectroscopy (fNIRS) recordings from 40 epileptic patients. Long short-term memory units and convolutional neural networks are integrated within a multimodal sequence-to-sequence autoencoder. The trained neural network predicts fNIRS signals from EEG, sans a priori, by hierarchically extracting deep features from EEG full spectra and specific EEG frequency bands. Results show that higher frequency EEG ranges are predictive of fNIRS signals with the gamma band inputs dominating fNIRS prediction as compared to other frequency envelopes. Seed based functional connectivity validates similar patterns between experimental fNIRS and our model's fNIRS reconstructions. This is the first study that shows it is possible to predict brain hemodynamics (fNIRS) from encoded neural data (EEG) in the resting human epileptic brain based on power spectrum amplitude modulation of frequency oscillations in the context of specific hypotheses about how EEG frequency bands decode fNIRS signals.
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20
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Gupta SK, Rutherford N, Dolja-Gore X, Watson T, Nair BR. Regional changes with global brain hypometabolism indicates a physiological triage phenomenon and can explain shared pathophysiological events in Alzheimer's & small vessel diseases and delirium. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2021; 11:492-506. [PMID: 35003887 PMCID: PMC8727878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/09/2021] [Indexed: 06/14/2023]
Abstract
While reduced global brain metabolism is known in aging, Alzheimer's disease (AD), small vessel disease (SVD) and delirium, explanation of regional brain metabolic (rBM) changes is a challenge. We hypothesized that this may be explained by "triage phenomenon", to preserve metabolic supply to vital brain areas. We studied changes in rBM in 69 patients with at least 5% decline in global brain metabolism during active lymphoma. There was significant decline in the rBM of the inferior parietal, precuneus, superior parietal, lateral occipital, primary visual cortices (P<0.001) and in the right lateral prefrontal cortex (P=0.01). Some areas showed no change; multiple areas had significantly increased rBM (e.g. medial prefrontal, anterior cingulate, pons, cerebellum and mesial temporal cortices; P<0.001). We conclude the existence of a physiological triage phenomenon and argue a new hypothetical model to explain the shared events in the pathophysiology of aging, AD, SVD and delirium.
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Affiliation(s)
- Sandeep K Gupta
- Department of Nuclear Medicine & PET, John Hunter and Calvary Mater Hospitals, Hunter Medical Research Institute (HMRI), University of NewcastleNewcastle, NSW, Australia
| | - Natalie Rutherford
- Department of Nuclear Medicine & PET, John Hunter and Calvary Mater Hospitals, Hunter Medical Research Institute (HMRI), University of NewcastleNewcastle, NSW, Australia
| | - Xenia Dolja-Gore
- Research Centre for Generational Health and Ageing (RCGHA), Faculty of Health and Medicine, University of NewcastleNewcastle, NSW, Australia
| | - Tahne Watson
- Department of Nuclear Medicine & PET, John Hunter and Calvary Mater Hospitals, Hunter Medical Research Institute (HMRI), University of NewcastleNewcastle, NSW, Australia
| | - Balakrishnan R Nair
- School of Medicine and Public Health, University of NewcastleNewcastle, NSW, Australia
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21
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Li Z, McConnell HL, Stackhouse TL, Pike MM, Zhang W, Mishra A. Increased 20-HETE Signaling Suppresses Capillary Neurovascular Coupling After Ischemic Stroke in Regions Beyond the Infarct. Front Cell Neurosci 2021; 15:762843. [PMID: 34819839 PMCID: PMC8606525 DOI: 10.3389/fncel.2021.762843] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/06/2021] [Indexed: 12/23/2022] Open
Abstract
Neurovascular coupling, the process by which neuronal activity elicits increases in the local blood supply, is impaired in stroke patients in brain regions outside the infarct. Such impairment may contribute to neurological deterioration over time, but its mechanism is unknown. Using the middle cerebral artery occlusion (MCAO) model of stroke, we show that neuronal activity-evoked capillary dilation is reduced by ∼75% in the intact cortical tissue outside the infarct border. This decrease in capillary responsiveness was not explained by a decrease in local neuronal activity or a loss of vascular contractility. Inhibiting synthesis of the vasoconstrictive molecule 20-hydroxyeicosatetraenoic acid (20-HETE), either by inhibiting its synthetic enzyme CYP450 ω-hydroxylases or by increasing nitric oxide (NO), which is a natural inhibitor of ω-hydroxylases, rescued activity-evoked capillary dilation. The capillary dilation unmasked by inhibiting 20-HETE was dependent on PGE2 activation of endoperoxide 4 (EP4) receptors, a vasodilatory pathway previously identified in healthy animals. Cortical 20-HETE levels were increased following MCAO, in agreement with data from stroke patients. Inhibition of ω-hydroxylases normalized 20-HETE levels in vivo and increased cerebral blood flow in the peri-infarct cortex. These data identify 20-HETE-dependent vasoconstriction as a mechanism underlying capillary neurovascular coupling impairment after stroke. Our results suggest that the brain's energy supply may be significantly reduced after stroke in regions previously believed to be asymptomatic and that ω-hydroxylase inhibition may restore healthy neurovascular coupling post-stroke.
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Affiliation(s)
- Zhenzhou Li
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
- Department of Anesthesiology, General Hospital of Ningxia Medical University, Ningxia, China
| | - Heather L. McConnell
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States
| | - Teresa L. Stackhouse
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States
| | - Martin M. Pike
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Wenri Zhang
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, United States
| | - Anusha Mishra
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States
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22
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Chen Q, Jin T, Qi W, Xi L. Dual-model wearable photoacoustic microscopy and electroencephalograph: study of neurovascular coupling in anesthetized and freely moving rats. BIOMEDICAL OPTICS EXPRESS 2021; 12:6614-6628. [PMID: 34745760 PMCID: PMC8547996 DOI: 10.1364/boe.438596] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/11/2021] [Accepted: 09/14/2021] [Indexed: 05/29/2023]
Abstract
Observing microscale neurovascular dynamics under different physiological conditions is of great importance to understanding brain functions and disorders. Here, we report a dual-model wearable device and an auxiliary data processing algorithm to derive neurovascular dynamics. The device integrates high-resolution photoacoustic microscopy and electroencephalography (EEG), which allows observing capillary-level hemodynamics and neural activities in anesthesia and freely moving rats. By using the developed algorithm, multiple photoacoustic/EEG parameters extracted and correlated enables investigation of the interplay between neural and vascular activities. We employed this platform to study the neurovascular coupling during different types of seizures in rats under various physiological conditions. We observed cerebral vascular vasodilation/constriction corresponding well to the seizure on/off in rats under regular anesthesia conditions, showing a strong neurovascular coupling coefficient. In rats under weak anesthesia and freely moving conditions, more intense cerebral hemodynamics and neural activities occurred with a weaker neurovascular coupling coefficient. The comprehensively quantitative analyses suggest that anesthesia has a dominant impact on the seizure onset and affect the neurovascular coupling correlation in the current drug-induced localized seizure model. Our study reveals that the designed platform has the potential to support studies on brain functions and disorders in diseased rodent models in various physiological states.
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Affiliation(s)
- Qian Chen
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Tian Jin
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Weizhi Qi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Lei Xi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
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23
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Li S, Wang C, Wang Z, Tan J. Involvement of cerebrovascular abnormalities in the pathogenesis and progression of Alzheimer's disease: an adrenergic approach. Aging (Albany NY) 2021; 13:21791-21806. [PMID: 34479211 PMCID: PMC8457611 DOI: 10.18632/aging.203482] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/17/2021] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD), as the most common neurodegenerative disease in elder population, is pathologically characterized by β-amyloid (Aβ) plaques, neurofibrillary tangles composed of highly-phosphorylated tau protein and consequently progressive neurodegeneration. However, both Aβ and tau fails to cover the whole pathological process of AD, and most of the Aβ- or tau-based therapeutic strategies are all failed. Increasing lines of evidence from both clinical and preclinical studies have indicated that age-related cerebrovascular dysfunctions, including the changes in cerebrovascular microstructure, blood-brain barrier integrity, cerebrovascular reactivity and cerebral blood flow, accompany or even precede the development of AD-like pathologies. These findings may raise the possibility that cerebrovascular changes are likely pathogenic contributors to the onset and progression of AD. In this review, we provide an appraisal of the cerebrovascular alterations in AD and the relationship to cognitive impairment and AD pathologies. Moreover, the adrenergic mechanisms leading to cerebrovascular and AD pathologies were further discussed. The contributions of early cerebrovascular factors, especially through adrenergic mechanisms, should be considered and treasured in the diagnostic, preventative, and therapeutic approaches to address AD.
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Affiliation(s)
- Song Li
- Liaoning Provincial Center for Clinical Research on Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian 116021, China.,Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital, Dalian Medical University, Dalian 116021, China
| | - Che Wang
- Department of Pharmaceutical Chemistry, School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, China
| | - Zhen Wang
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Jun Tan
- Key Laboratory of Endemic and Ethnic Diseases, Guizhou Medical University, Guiyang 550004, China
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24
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Cheung CY, Mok V, Foster PJ, Trucco E, Chen C, Wong TY. Retinal imaging in Alzheimer's disease. J Neurol Neurosurg Psychiatry 2021; 92:983-994. [PMID: 34108266 DOI: 10.1136/jnnp-2020-325347] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/27/2021] [Indexed: 12/11/2022]
Abstract
Identifying biomarkers of Alzheimer's disease (AD) will accelerate the understanding of its pathophysiology, facilitate screening and risk stratification, and aid in developing new therapies. Developments in non-invasive retinal imaging technologies, including optical coherence tomography (OCT), OCT angiography and digital retinal photography, have provided a means to study neuronal and vascular structures in the retina in people with AD. Both qualitative and quantitative measurements from these retinal imaging technologies (eg, thinning of peripapillary retinal nerve fibre layer, inner retinal layer, and choroidal layer, reduced capillary density, abnormal vasodilatory response) have been shown to be associated with cognitive function impairment and risk of AD. The development of computer algorithms for respective retinal imaging methods has further enhanced the potential of retinal imaging as a viable tool for rapid, early detection and screening of AD. In this review, we present an update of current retinal imaging techniques and their potential applications in AD research. We also discuss the newer retinal imaging techniques and future directions in this expanding field.
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Affiliation(s)
- Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Vincent Mok
- Gerald Choa Neuroscience Centre, Therese Pei Fong Chow Research Centre for Prevention of Dementia, Lui Che Woo Institute of Innovative Medicine, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Paul J Foster
- National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, NHS Foundation Trust, UCL Institute of Ophthalmology, London, UK
| | - Emanuele Trucco
- VAMPIRE project, Computing, School of Science and Engineering, University of Dundee, Dundee, UK
| | - Christopher Chen
- Pharmacology, National University Singapore Yong Loo Lin School of Medicine, Singapore.,Memory Aging and Cognition Centre, National University Health System, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore
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25
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Ge YJ, Xu W, Ou YN, Qu Y, Ma YH, Huang YY, Shen XN, Chen SD, Tan L, Zhao QH, Yu JT. Retinal biomarkers in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis. Ageing Res Rev 2021; 69:101361. [PMID: 34000463 DOI: 10.1016/j.arr.2021.101361] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022]
Abstract
BACKGROUND Retinal changes may reflect the pathophysiological processes in the central nervous system and can be assessed by imaging modalities non-invasively. We aim to localize candidate retinal biomarkers in Alzheimer's disease (AD), mild cognitive impairment (MCI), and preclinical AD. METHODS We systematically searched PubMed, EMBASE, Scopus, and Web of Science from inception to January 2021 for observational studies that investigated retinal imaging and electrophysiological markers in AD, MCI, and preclinical AD. Between-groups standardized mean differences (SMDs) with 95 % confidence intervals were computed using random-effects models. RESULTS Of 19,727 citations identified, 126 articles were eligible for inclusion. Compared with healthy controls, the thickness of peripapillary retinal nerve fiber layer (pRNFL; SMD = -0.723, p < 0.001), total macular (SMD = -0.612, p < 0.001), and subfoveal choroid (SMD = -0.888, p < 0.001) were significantly reduced in patients with AD. Compared with healthy controls, patients with MCI also had lower thickness of pRNFL (SMD = -0.324, p < 0.001), total macular (SMD = -0.302, p < 0.001), and subfoveal choroid (SMD = -0.462, p = 0.020). Other candidate biomarkers included the optic nerve head morphology, retinal amyloid deposition, microvascular morphology and densities, blood flow, and electrophysiological markers. CONCLUSIONS Retinal structural, vascular, and electrophysiological biomarkers hold great potential for the diagnosis, prognosis and risk assessment of AD and MCI. These biomarkers warrant further development in the future, especially in diagnostic test accuracy and longitudinal studies.
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26
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Turner DA. Contrasting Metabolic Insufficiency in Aging and Dementia. Aging Dis 2021; 12:1081-1096. [PMID: 34221551 PMCID: PMC8219502 DOI: 10.14336/ad.2021.0104] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 01/04/2021] [Indexed: 12/14/2022] Open
Abstract
Metabolic insufficiency and neuronal dysfunction occur in normal aging but is exaggerated in dementia and Alzheimer's disease (AD). Metabolic insufficiency includes factors important for both substrate supply and utilization in the brain. Metabolic insufficiency occurs through a number of serial mechanisms, particularly changes in cerebrovascular supply through blood vessel abnormalities (ie, small and large vessel vasculopathy, stroke), alterations in neurovascular coupling providing dynamic blood flow supply in relation to neuronal demand, abnormalities in blood brain barrier including decreased glucose and amino acid transport, altered glymphatic flow in terms of substrate supply across the extracellular space to cells and drainage into CSF of metabolites, impaired transport into cells, and abnormal intracellular metabolism with more reliance on glycolysis and less on mitochondrial function. Recent studies have confirmed abnormal neurovascular coupling in a mouse model of AD in response to metabolic challenges, but the supply chain from the vascular system into neurons is disrupted much earlier in dementia than in equivalently aged individuals, contributing to the progressive neuronal degeneration and cognitive dysfunction associated with dementia. We discuss several metabolic treatment approaches, but these depend on characterizing patients as to who would benefit the most. Surrogate biomarkers of metabolism are being developed to include dynamic estimates of neuronal demand, sufficiency of neurovascular coupling, and glymphatic flow to supplement traditional static measurements. These surrogate biomarkers could be used to gauge efficacy of metabolic treatments in slowing down or modifying dementia time course.
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Affiliation(s)
- Dennis A Turner
- Neurosurgery, Neurobiology, and Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, USA.
- Research and Surgery Services, Durham Veterans Affairs Medical Center, Durham, NC 27705, USA.
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27
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Albanna W, Conzen C, Weiss M, Seyfried K, Kotliar K, Schmidt TP, Kuerten D, Hescheler J, Bruecken A, Schmidt-Trucksäss A, Neumaier F, Wiesmann M, Clusmann H, Schubert GA. Non-invasive Assessment of Neurovascular Coupling After Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Trial Using Retinal Vessel Analysis. Front Neurol 2021; 12:690183. [PMID: 34194387 PMCID: PMC8236540 DOI: 10.3389/fneur.2021.690183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/18/2021] [Indexed: 12/17/2022] Open
Abstract
Objective: Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus. Methods: Static and dynamic RVA were performed using a Retinal Vessel Analyzer (IMEDOS Systems GmbH, Jena) in 70 aSAH patients during the early (d0-4), critical (d5-15), late (d16-23) phase, and at follow-up (f/u > 6 weeks) after the ictus. For comparison, an age-matched cohort of 42 healthy subjects was also included in the study. Vessel diameters were quantified in terms of the central retinal arterial and venous equivalent (CRAE, CRVE) and the retinal arterio-venous-ratio (AVR). Vessel responses to flicker light excitation (FLE) were quantified by recording the maximum arterial and venous dilation (MAD, MVD), the time to 30% and 100% of maximum dilation (tMAD30, tMVD30; tMAD, tMVD, resp.), and the arterial and venous area under the curve (AUCart, AUCven) during the FLE. For subgroup analyses, patients were stratified according to the development of DCI and clinical outcomes after 12 months. Results: Vessel diameter (CRAE, CRVE) was significantly smaller in aSAH patients and showed little change throughout the whole observation period (p < 0.0001 vs. control for all time periods examined). In addition, aSAH patients exhibited impaired arterial but not venous responses to FLE, as reflected in a significantly lower MAD [2.2 (1.0-3.2)% vs. 3.6 (2.6-5.6)% in control subjects, p = 0.0016] and AUCart [21.5 (9.4-35.8)%*s vs. 51.4 (32.5-69.7)%*s in control subjects, p = 0.0001] on d0-4. However, gradual recovery was observed during the first 3 weeks, with close to normal levels at follow-up, when MAD and AUCart amounted to 3.0 [2.0-5.0]% (p = 0.141 vs. control, p = 0.0321 vs. d5-15) and 44.5 [23.2-61.1]%*s (p = 0.138 vs. control, p < 0.01 vs. d0-4 & d5-15). Finally, patients with clinical deterioration (DCI) showed opposite changes in the kinetics of arterial responses during early and late phase, as reflected in a significantly lower tMAD30 on d0-4 [4.0 (3.0-6.8) s vs. 7.0 (5.0-8.0) s in patients without DCI, p = 0.022) and a significantly higher tMAD on d16-23 (24.0 (21.0-29.3) s vs. 18.0 (14.0-21.0) s in patients without DCI, p = 0.017]. Conclusion: Our findings confirm and extend previous observations that aSAH results in sustained impairments of NVC in the retina. DCI may be associated with characteristic changes in the kinetics of retinal arterial responses. However, further studies will be required to determine their clinical implications and to assess if they can be used to identify patients at risk of developing DCI. Trial Registration: ClinicalTrials.gov Identifier: NCT04094155.
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Affiliation(s)
- Walid Albanna
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany.,Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Catharina Conzen
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Miriam Weiss
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | | | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Aachen, Germany
| | | | - David Kuerten
- Department of Ophthalmology, RWTH Aachen University, Aachen, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Anne Bruecken
- Department of Intensive Care and Intermediate Care, RWTH Aachen University, Aachen, Germany
| | | | - Felix Neumaier
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Martin Wiesmann
- Department of Diagnostic and Interventional Neuroradiology, RWTH Aachen University, Aachen, Germany
| | - Hans Clusmann
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
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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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Jacobs A, Pieters M, Smith W, Schutte AE. Retinal vasodilatory responses are inversely associated with plasminogen activator inhibitor-1: The African-PREDICT study. Microvasc Res 2021; 137:104180. [PMID: 34015274 DOI: 10.1016/j.mvr.2021.104180] [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: 02/08/2021] [Revised: 04/28/2021] [Accepted: 05/13/2021] [Indexed: 11/18/2022]
Abstract
AIMS Plasminogen activator inhibitor-1 (PAI-1), traditionally associated with fibrinolysis, is increasingly implicated in impaired vascular function. However, studies on its association with microvascular function are limited to the cutaneous and coronary microvascular beds in older and diseased individuals. To better understand its potential involvement in the early stages of disease development, we investigated the associations of retinal vasodilatory responses to flicker light with PAI-1 activity (PAI-1act) in young and healthy individuals. METHODS We included healthy Black and White women and men (n = 518; aged 20-30 years), and measured plasma PAI-1act and retinal vasodilatory responses to flicker light provocation. We also collected demographic and lifestyle data, measured blood pressure, anthropometry, blood lipids, inflammatory and other biomarkers. RESULTS In multivariate regression analyses, maximal retinal venular dilation associated independently and inversely with PAI-1act (adj. R2 = 0.11; β = -0.15; p = 0.001) in the total group. In exploratory subgroup analyses, this association remained in White women (adj. R2 = 0.07; β = -0.23; p = 0.005), and was more robust with younger age and lower blood pressure and in non-smokers, but also with greater central adiposity, higher low-density lipoprotein cholesterol and inflammation (all p < 0.05). CONCLUSIONS Our data suggest that in young individuals, PAI-1 may already be associated with subclinical microvascular dysfunction.
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Affiliation(s)
- Adriaan Jacobs
- Hypertension in Africa Research Team (HART), North-West University, Private bag X1290, Potchefstroom, South Africa; Medical Research Council Unit for Hypertension and Cardiovascular Disease, North-West University, Private bag X6001, Potchefstroom, South Africa.
| | - Marlien Pieters
- Medical Research Council Unit for Hypertension and Cardiovascular Disease, North-West University, Private bag X6001, Potchefstroom, South Africa; Centre of Excellence for Nutrition (CEN), North-West University, Private bag X6001, Potchefstroom, South Africa.
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Private bag X1290, Potchefstroom, South Africa; Medical Research Council Unit for Hypertension and Cardiovascular Disease, North-West University, Private bag X6001, Potchefstroom, South Africa.
| | - Aletta E Schutte
- Hypertension in Africa Research Team (HART), North-West University, Private bag X1290, Potchefstroom, South Africa; Medical Research Council Unit for Hypertension and Cardiovascular Disease, North-West University, Private bag X6001, Potchefstroom, South Africa; School of Population Health, University of New South Wales, The George Institute for Global Health, Sydney, NSW 2052, Australia.
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Neumaier F, Kotliar K, Haeren RHL, Temel Y, Lüke JN, Seyam O, Lindauer U, Clusmann H, Hescheler J, Schubert GA, Schneider T, Albanna W. Retinal Vessel Responses to Flicker Stimulation Are Impaired in Ca v 2.3-Deficient Mice-An in-vivo Evaluation Using Retinal Vessel Analysis (RVA). Front Neurol 2021; 12:659890. [PMID: 33927686 PMCID: PMC8076560 DOI: 10.3389/fneur.2021.659890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/17/2021] [Indexed: 12/30/2022] Open
Abstract
Objective: Metabolic demand increases with neuronal activity and adequate energy supply is ensured by neurovascular coupling (NVC). Impairments of NVC have been reported in the context of several diseases and may correlate with disease severity and outcome. Voltage-gated Ca2+-channels (VGCCs) are involved in the regulation of vasomotor tone. In the present study, we compared arterial and venous responses to flicker stimulation in Cav2.3-competent (Cav2.3[+/+]) and -deficient (Cav2.3[-/-]) mice using retinal vessel analysis. Methods: The mice were anesthetized and the pupil of one eye was dilated by application of a mydriaticum. An adapted prototype of retinal vessel analyzer was used to perform dynamic retinal vessel analysis. Arterial and venous responses were quantified in terms of the area under the curve (AUCart/AUCven) during flicker application, mean maximum dilation (mMDart/mMDven) and time to maximum dilation (tMDart/tMDven) during the flicker, dilation at flicker cessation (DFCart/DFCven), mean maximum constriction (mMCart/mMCven), time to maximum constriction (tMCart/tMCven) after the flicker and reactive magnitude (RMart/RMven). Results: A total of 33 retinal scans were conducted in 22 Cav2.3[+/+] and 11 Cav2.3[-/-] mice. Cav2.3[-/-] mice were characterized by attenuated and partially reversed arterial and venous responses, as reflected in significantly lower AUCart (p = 0.031) and AUCven (p = 0.047), a trend toward reduced DFCart (p = 0.100), DFCven (p = 0.100), mMDven (p = 0.075), and RMart (p = 0.090) and a trend toward increased tMDart (p = 0.096). Conclusion: To our knowledge, this is the first study using a novel, non-invasive analysis technique to document impairment of retinal vessel responses in VGCC-deficient mice. We propose that Cav2.3 channels could be involved in NVC and may contribute to the impairment of vasomotor responses under pathophysiological conditions.
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Affiliation(s)
- Felix Neumaier
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Jülich, Germany
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Aachen, Germany
| | | | - Yasin Temel
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, Netherlands
| | - Jan Niklas Lüke
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Osama Seyam
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Aachen, Germany
| | - Ute Lindauer
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
- Tranlational Neurosurgery and Neurobiology, RWTH Aachen University, Aachen, Germany
| | - Hans Clusmann
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
| | - Jürgen Hescheler
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | | | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Walid Albanna
- Department of Neurosurgery, RWTH Aachen University, Aachen, Germany
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
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Chiarelli AM, Perpetuini D, Croce P, Filippini C, Cardone D, Rotunno L, Anzoletti N, Zito M, Zappasodi F, Merla A. Evidence of Neurovascular Un-Coupling in Mild Alzheimer's Disease through Multimodal EEG-fNIRS and Multivariate Analysis of Resting-State Data. Biomedicines 2021; 9:biomedicines9040337. [PMID: 33810484 PMCID: PMC8066873 DOI: 10.3390/biomedicines9040337] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/20/2021] [Accepted: 03/23/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is associated with modifications in cerebral blood perfusion and autoregulation. Hence, neurovascular coupling (NC) alteration could become a biomarker of the disease. NC might be assessed in clinical settings through multimodal electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). Multimodal EEG-fNIRS was recorded at rest in an ambulatory setting to assess NC and to evaluate the sensitivity and specificity of the methodology to AD. Global NC was evaluated with a general linear model (GLM) framework by regressing whole-head EEG power envelopes in three frequency bands (theta, alpha and beta) with average fNIRS oxy- and deoxy-hemoglobin concentration changes in the frontal and prefrontal cortices. NC was lower in AD compared to healthy controls (HC) with significant differences in the linkage of theta and alpha bands with oxy- and deoxy-hemoglobin, respectively (p = 0.028 and p = 0.020). Importantly, standalone EEG and fNIRS metrics did not highlight differences between AD and HC. Furthermore, a multivariate data-driven analysis of NC between the three frequency bands and the two hemoglobin species delivered a cross-validated classification performance of AD and HC with an Area Under the Curve, AUC = 0.905 (p = 2.17 × 10−5). The findings demonstrate that EEG-fNIRS may indeed represent a powerful ecological tool for clinical evaluation of NC and early identification of AD.
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Affiliation(s)
- Antonio M. Chiarelli
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
- Correspondence: ; Tel.: +39-087-1355-6954
| | - David Perpetuini
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
| | - Pierpaolo Croce
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
| | - Chiara Filippini
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
| | - Daniela Cardone
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
| | - Ludovica Rotunno
- Department of Medicine and Science of Ageing, Faculty of Medicine, University G. d’Annunzio of Chieti-Pescara, Via Dei Vestini 31, 66100 Chieti, Italy; (L.R.); (N.A.); (M.Z.)
| | - Nelson Anzoletti
- Department of Medicine and Science of Ageing, Faculty of Medicine, University G. d’Annunzio of Chieti-Pescara, Via Dei Vestini 31, 66100 Chieti, Italy; (L.R.); (N.A.); (M.Z.)
| | - Michele Zito
- Department of Medicine and Science of Ageing, Faculty of Medicine, University G. d’Annunzio of Chieti-Pescara, Via Dei Vestini 31, 66100 Chieti, Italy; (L.R.); (N.A.); (M.Z.)
| | - Filippo Zappasodi
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
| | - Arcangelo Merla
- Department of Neuroscience, Imaging and Clinical Sciences, Institute for Advanced Biomedical Technologies, Faculty of Medicine, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (D.P.); (P.C.); (C.F.); (D.C.); (F.Z.); (A.M.)
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Malan L, Hamer M, von Känel R, van Wyk RD, Sumner AE, Nilsson PM, Lambert GW, Steyn HS, Badenhorst CJ, Malan NT. A Stress Syndrome Prototype Reflects Type 3 Diabetes and Ischemic Stroke Risk: The SABPA Study. BIOLOGY 2021; 10:162. [PMID: 33670473 PMCID: PMC7922484 DOI: 10.3390/biology10020162] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/28/2021] [Accepted: 02/09/2021] [Indexed: 12/19/2022]
Abstract
Type 3 diabetes (T3D) accurately reflects that dementia, e.g., Alzheimer's disease, represents insulin resistance and neurodegeneration in the brain. Similar retinal microvascular changes were observed in Alzheimer's and chronic stressed individuals. Hence, we aimed to show that chronic stress relates to T3D dementia signs and retinopathy, ultimately comprising a Stress syndrome prototype reflecting risk for T3D and stroke. A chronic stress and stroke risk phenotype (Stressed) score, independent of age, race or gender, was applied to stratify participants (N = 264; aged 44 ± 9 years) into high stress risk (Stressed, N = 159) and low stress risk (non-Stressed, N = 105) groups. We determined insulin resistance using the homeostatic model assessment (HOMA-IR), which is interchangeable with T3D, and dementia risk markers (cognitive executive functioning (cognitiveexe-func); telomere length; waist circumference (WC), neuronal glia injury; neuron-specific enolase/NSE, S100B). Retinopathy was determined in the mydriatic eye. The Stressed group had greater incidence of HOMA-IR in the upper quartile (≥5), larger WC, poorer cognitiveexe-func control, shorter telomeres, consistently raised neuronal glia injury, fewer retinal arteries, narrower arteries, wider veins and a larger optic cup/disc ratio (C/D) compared to the non-Stressed group. Furthermore, of the stroke risk markers, arterial narrowing was related to glaucoma risk with a greater C/D, whilst retinal vein widening was related to HOMA-IR, poor cognitiveexe-func control and neuronal glia injury (Adjusted R2 0.30; p ≤ 0.05). These associations were not evident in the non-Stressed group. Logistic regression associations between the Stressed phenotype and four dementia risk markers (cognitiveexe-func, telomere length, NSE and WC) comprised a Stress syndrome prototype (area under the curve 0.80; sensitivity/specificity 85%/58%; p ≤ 0.001). The Stress syndrome prototype reflected risk for HOMA-IR (odds ratio (OR) 7.72) and retinal glia ischemia (OR 1.27) and vein widening (OR 1.03). The Stressed phenotype was associated with neuronal glia injury and retinal ischemia, potentiating glaucoma risk. The detrimental effect of chronic stress exemplified a Stress syndrome prototype reflecting risk for type 3 diabetes, neurodegeneration and ischemic stroke.
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Affiliation(s)
- Leoné Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom 2520, South Africa; (R.v.K.); (N.T.M.)
| | - Mark Hamer
- Division of Surgery & Interventional Science, Faculty of Medical Sciences, University College London, London WC1E 6BT, UK;
| | - Roland von Känel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom 2520, South Africa; (R.v.K.); (N.T.M.)
- Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Roelof D. van Wyk
- Surgical Ophthalmologist, 85 Peter Mokaba Street, Potchefstroom 2531, South Africa;
| | - Anne E. Sumner
- Section on Ethnicity and Health, Diabetes, Endocrinology and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA;
- National Institute of Minority Health and Health Disparities, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter M. Nilsson
- Department of Clinical Sciences, Lund University, SE-205 02 Malmö, Sweden;
| | - Gavin W. Lambert
- Iverson Health Innovation Research Institute, Swinburne University of Technology, Hawthorn, VIC 3122, Australia;
- Baker Heart & Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Hendrik S. Steyn
- Statistical Consultation Services, North-West University, Potchefstroom 2520, South Africa;
| | - Casper J. Badenhorst
- Anglo American Corporate Services, Sustainable Development Department, Johannesburg 2017, South Africa;
| | - Nico T. Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom 2520, South Africa; (R.v.K.); (N.T.M.)
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Werfel S, Günthner R, Hapfelmeier A, Hanssen H, Kotliar K, Heemann U, Schmaderer C. Identification of cardiovascular high risk groups from dynamic retinal vessel signals using untargeted machine learning. Cardiovasc Res 2021; 118:612-621. [PMID: 33576412 DOI: 10.1093/cvr/cvab040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 02/09/2021] [Indexed: 12/11/2022] Open
Abstract
AIMS Dynamic retinal vessel analysis (DVA) provides a noninvasive way to asses microvascular function in patients and potentially to improve predictions of individual cardiovascular (CV) risk. The aim of our study was to use untargeted machine learning on DVA in order to improve CV mortality prediction and to identify corresponding response alterations. METHODS AND RESULTS We adopted a workflow consisting of noise reduction and extraction of independent components within DVA signals. Predictor performance was assessed in survival random forest models. Applying our technique to the prediction of all-cause mortality in a cohort of 214 hemodialysis patients resulted in the selection of a component which was highly correlated to maximal venous dilation following flicker stimulation (vMax), a previously identified predictor, confirming the validity of our approach. When fitting for CV mortality as the outcome of interest, a combination of three components derived from the arterial signal resulted in a marked improvement in predictive performance. Clustering analysis suggested that these independent components identified groups of patients with substantially higher CV mortality. CONCLUSIONS Our results provide a machine learning workflow to improve the predictive performance of DVA and identify groups of hemodialysis patients at high risk of CV mortality. Our approach may also prove to be promising for DVA signal analysis in other CV disease states. TRANSLATIONAL PERSPECTIVE DVA is a noninvasive technique which can help to assess microvascular dysfunction, one of the driving factors of CV disease. This study demonstrates a machine learning method which improves DVA interpretation for the estimation of CV risk in hemodialysis patients. Similar techniques can help doctors to identify high risk patients for timely therapeutic interventions and to monitor the effects of these interventions.
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Affiliation(s)
- Stanislas Werfel
- Department of Nephrology, Klinikum Rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675 Munich, Germany
| | - Roman Günthner
- Department of Nephrology, Klinikum Rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675 Munich, Germany
| | - Alexander Hapfelmeier
- Institute of Medical Informatics, Statistics and Epidemiology, School of Medicine, Technical University Munich, Munich, Germany
- Institute of General Practice and Health Services Research, School of Medicine, Technical University Munich, Munich, Germany
| | - Henner Hanssen
- Division of Sports Medicine, Institute of Exercise and Health Sciences (ISSW), University of Basel, Basel, Switzerland
| | - Konstantin Kotliar
- Department of Biomedical Engineering and Technomathematics, Aachen University of Applied Sciences, Juelich, Germany
| | - Uwe Heemann
- Department of Nephrology, Klinikum Rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675 Munich, Germany
| | - Christoph Schmaderer
- Department of Nephrology, Klinikum Rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675 Munich, Germany
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Malan L, Hamer M, von Känel R, Kotliar K, van Wyk RD, Lambert GW, Vilser W, Ziemssen T, Schlaich MP, Smith W, Magnusson M, Wentzel A, Myburgh CE, Steyn HS, Malan NT. Delayed retinal vein recovery responses indicate both non-adaptation to stress as well as increased risk for stroke: the SABPA study. Cardiovasc J Afr 2021; 32:5-16. [PMID: 33104153 PMCID: PMC8756074 DOI: 10.5830/cvja-2020-031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 08/07/2020] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVES Low or high sympatho-adrenal-medullary axis (SAM) and hypothalamic-pituitary-adrenal axis (HPA) dysregulation reflect chronic stress. Retinal vessel dynamics may relate to SAM, HPA activity and stroke risk. Our objectives were therefore to assess the relationships between retinal vessel, SAM and HPA responses, and to determine stroke risk. METHODS A prospective bi-ethnic gender cohort (n = 275, 45 ± 9 years) was included. Urine/serum/saliva samples for SAM [norepinephrine:creatinine ratio (u-NE)] and HPA [adrenocorticotrophic hormone (ACTH), cortisol] were obtained at baseline, three-year follow up and upon flicker light-induced provocation. Diastolic ocular perfusion pressure was measured as a marker of hypo-perfusion. Retinal arterial narrowing and venous widening calibres were quantified from digital images in the mydriatic eye. A validated stress and stroke risk score was applied. RESULTS An interaction term was fitted for venous dilation in u-NE tertiles (p ≤ 0.05) and not in u-NE median/quartiles/quintiles. Independent of race or gender, tertile 1 (low u-NE) had a 112% increase in u-NE, decreases in cortisol, and no changes in ACTH over three years (positive feedback). Tertile 3 (high u-NE) contradictorily had decreases in u-NE and cortisol, and increases in ACTH (negative feedback). In tertile 1, reduced arterial dilation, and faster arterial vasoconstriction and narrowing were related to higher SAM activity and hypo-perfusion (p ≤ 0.05), whereas delayed venous dilation, recovery and widening were related to cortisol hypo-secretion (p ≤ 0.05). In tertile 1, delayed venous recovery responses predicted stress and stroke risk [odds ratio 4.8 (1.2-19.6); p = 0.03]. These associations were not found in u-NE tertiles 2 and 3. CONCLUSIONS In response to low norepinephrine, a reflex increase in SAM activity occurred, enhancing arterial vasoconstriction and hypo-perfusion. Concomitant HPA dysregulation attenuated retinal vein vasoactivity and tone, reflecting delayed vein recovery responses and non-adaptation to stress. These constrained vein recovery responses are indicative of increased chronic stress and stroke risk.
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Affiliation(s)
- Leoné Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
| | - Mark Hamer
- Division of Surgery & Interventional Science, Faculty of Medical Sciences, University College London, United Kingdom
| | - Roland von Känel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, University Hospital Zurich 8091, Switzerland
| | - Konstantin Kotliar
- Department of Medical Engineering and Technomathematics, FH Aachen University of Applied Sciences, Jülich, Germany
| | | | - Gavin W Lambert
- Iverson Health Innovation Research Institute, Swinburne University of Technology, Hawthorn; Baker Heart & Diabetes Institute, Melbourne, Australia
| | | | - Tjalf Ziemssen
- Autonomic and Neuroendocrinological Laboratory Dresden, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Markus P Schlaich
- Dobney Hypertension Centre, School of Medicine, Royal Perth Hospital Unit, University Western Australia, Perth, Australia
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Medical Research Council Research Unit: Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Martin Magnusson
- Department of Clinical Sciences, Malmö, Lund University; Wallenberg Centre for Molecular Medicine, Malmö, Lund University; Department of Cardiology, Malmö, Skåne University Hospital, Sweden
| | - Annemarie Wentzel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
| | - Carlien E Myburgh
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
| | - Hendrik S Steyn
- Statistical Consultation Services, North-West University, Potchefstroom, South Africa
| | - Nico T Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
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Perpetuini D, Chiarelli AM, Filippini C, Cardone D, Croce P, Rotunno L, Anzoletti N, Zito M, Zappasodi F, Merla A. Working Memory Decline in Alzheimer's Disease Is Detected by Complexity Analysis of Multimodal EEG-fNIRS. ENTROPY (BASEL, SWITZERLAND) 2020; 22:E1380. [PMID: 33279924 PMCID: PMC7762102 DOI: 10.3390/e22121380] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is characterized by working memory (WM) failures that can be assessed at early stages through administering clinical tests. Ecological neuroimaging, such as Electroencephalography (EEG) and functional Near Infrared Spectroscopy (fNIRS), may be employed during these tests to support AD early diagnosis within clinical settings. Multimodal EEG-fNIRS could measure brain activity along with neurovascular coupling (NC) and detect their modifications associated with AD. Data analysis procedures based on signal complexity are suitable to estimate electrical and hemodynamic brain activity or their mutual information (NC) during non-structured experimental paradigms. In this study, sample entropy of whole-head EEG and frontal/prefrontal cortex fNIRS was evaluated to assess brain activity in early AD and healthy controls (HC) during WM tasks (i.e., Rey-Osterrieth complex figure and Raven's progressive matrices). Moreover, conditional entropy between EEG and fNIRS was evaluated as indicative of NC. The findings demonstrated the capability of complexity analysis of multimodal EEG-fNIRS to detect WM decline in AD. Furthermore, a multivariate data-driven analysis, performed on these entropy metrics and based on the General Linear Model, allowed classifying AD and HC with an AUC up to 0.88. EEG-fNIRS may represent a powerful tool for the clinical evaluation of WM decline in early AD.
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Affiliation(s)
- David Perpetuini
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
| | - Antonio Maria Chiarelli
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
| | - Chiara Filippini
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
| | - Daniela Cardone
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
| | - Pierpaolo Croce
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
| | - Ludovica Rotunno
- Department of Medicine and Science of Ageing, University G. D’Annunzio, Via Dei Vestini 31, 66100 Chieti, Italy; (L.R.); (N.A.); (M.Z.)
| | - Nelson Anzoletti
- Department of Medicine and Science of Ageing, University G. D’Annunzio, Via Dei Vestini 31, 66100 Chieti, Italy; (L.R.); (N.A.); (M.Z.)
| | - Michele Zito
- Department of Medicine and Science of Ageing, University G. D’Annunzio, Via Dei Vestini 31, 66100 Chieti, Italy; (L.R.); (N.A.); (M.Z.)
| | - Filippo Zappasodi
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
| | - Arcangelo Merla
- Institute for Advanced Biomedical Technologies, Department of Neuroscience and Imaging, University G. D’Annunzio of Chieti-Pescara, Via Luigi Polacchi 13, 66100 Chieti, Italy; (A.M.C.); (C.F.); (D.C.); (P.C.); (F.Z.); (A.M.)
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Czakó C, Kovács T, Ungvari Z, Csiszar A, Yabluchanskiy A, Conley S, Csipo T, Lipecz A, Horváth H, Sándor GL, István L, Logan T, Nagy ZZ, Kovács I. Retinal biomarkers for Alzheimer's disease and vascular cognitive impairment and dementia (VCID): implication for early diagnosis and prognosis. GeroScience 2020; 42:1499-1525. [PMID: 33011937 PMCID: PMC7732888 DOI: 10.1007/s11357-020-00252-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/10/2020] [Indexed: 12/11/2022] Open
Abstract
Cognitive impairment and dementia are major medical, social, and economic public health issues worldwide with significant implications for life quality in older adults. The leading causes are Alzheimer's disease (AD) and vascular cognitive impairment/dementia (VCID). In both conditions, pathological alterations of the cerebral microcirculation play a critical pathogenic role. Currently, the main pathological biomarkers of AD-β-amyloid peptide and hyperphosphorylated tau proteins-are detected either through cerebrospinal fluid (CSF) or PET examination. Nevertheless, given that they are invasive and expensive procedures, their availability is limited. Being part of the central nervous system, the retina offers a unique and easy method to study both neurodegenerative disorders and cerebral small vessel diseases in vivo. Over the past few decades, a number of novel approaches in retinal imaging have been developed that may allow physicians and researchers to gain insights into the genesis and progression of cerebromicrovascular pathologies. Optical coherence tomography (OCT), OCT angiography, fundus photography, and dynamic vessel analyzer (DVA) are new imaging methods providing quantitative assessment of retinal structural and vascular indicators-such as thickness of the inner retinal layers, retinal vessel density, foveal avascular zone area, tortuosity and fractal dimension of retinal vessels, and microvascular dysfunction-for cognitive impairment and dementia. Should further studies need to be conducted, these retinal alterations may prove to be useful biomarkers for screening and monitoring dementia progression in clinical routine. In this review, we seek to highlight recent findings and current knowledge regarding the application of retinal biomarkers in dementia assessment.
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Affiliation(s)
- Cecilia Czakó
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Tibor Kovács
- Department of Neurology, Semmelweis University, Budapest, Hungary
| | - Zoltan Ungvari
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Anna Csiszar
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Andriy Yabluchanskiy
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shannon Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Tamas Csipo
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Agnes Lipecz
- Translational Geroscience Laboratory, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Vascular Cognitive Impairment and Neurodegeneration Program, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Ophthalmology, Josa Andras Hospital, Nyiregyhaza, Hungary
| | - Hajnalka Horváth
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | | | - Lilla István
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Trevor Logan
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Illés Kovács
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary.
- Department of Ophthalmology, Weill Cornell Medical College, New York City, NY, USA.
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Szegedi S, Dal‐Bianco P, Stögmann E, Traub‐Weidinger T, Rainer M, Masching A, Schmidl D, Werkmeister RM, Chua J, Schmetterer L, Garhöfer G. Anatomical and functional changes in the retina in patients with Alzheimer's disease and mild cognitive impairment. Acta Ophthalmol 2020; 98:e914-e921. [PMID: 32212415 PMCID: PMC7687124 DOI: 10.1111/aos.14419] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/04/2020] [Indexed: 01/14/2023]
Abstract
PURPOSE There is evidence that mild cognitive impairment (MCI) or Alzheimer's disease (AD) is accompanied by alterations in the retina. The current study was performed to investigate structural and functional changes in patients with systemic neurodegenerative disease. METHODS A total of 47 patients with either MCI or AD and 43 healthy age- and sex-matched control subjects were included. Inclusion criteria for MCI were abnormal memory function and a mini-mental state examination (MMSE) score >26 points, for patients with AD a diagnosis of probable AD of mild to moderate degree and an MMSE score in the range of 20-26. Retinal blood flow was measured using a Doppler optical coherence tomography (OCT) system. Retinal vessel diameter, oxygen saturation and flicker-induced vasodilatation were measured using a Vessel Analyzer. Retinal nerve fibre layer thickness (RNFLT) was assessed using an OCT system. RESULTS Global RNFLT was lower in patients compared to healthy controls (93.7 ± 12.8 µm versus 99.1 ± 9.0 µm, p = 0.02). The same was found in regards to retinal arterial blood flow, which was 9.3 ± 2.4 and 12.3 ± 3.2 μl/min in the patient and control groups, respectively (p < 0.001). Mean retinal arterial diameter was reduced in patients (76.0 ± 8.9 µm versus 80.6 ± 8.0 µm, p = 0.03). Arteriovenous difference in oxygen saturation was lower in patients (20.4 ± 5.1% versus 23.5 ± 4.0%, p < 0.01). No difference in the flicker response was observed. CONCLUSION In patients with MCI and AD, arteriovenous difference in oxygen saturation, retinal blood flow and arterial vessel diameter was reduced. No difference was found in flicker response between groups. This indicates alterations in retinal oxygen metabolism in patients with neurodegenerative disease.
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Affiliation(s)
- Stephan Szegedi
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
| | - Peter Dal‐Bianco
- Department of NeurologyMedical University of ViennaViennaAustria
| | | | - Tatjana Traub‐Weidinger
- Division of Nuclear MedicineDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria
| | - Michael Rainer
- Department of PsychiatrySocial and Medical Centre East – Danube HospitalViennaAustria
- Karl Landsteiner Institute for Memory and Alzheimer ResearchViennaAustria
| | - Andreas Masching
- Department of PsychiatrySocial and Medical Centre East – Danube HospitalViennaAustria
| | - Doreen Schmidl
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
| | - René M. Werkmeister
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Jacqueline Chua
- Singapore Eye Research InstituteSingapore National Eye CentreSingapore CitySingapore
- Ophthalmology and Visual Sciences Academic Clinical ProgramDuke‐NUS Medical SchoolSingapore CitySingapore
| | - Leopold Schmetterer
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
- Singapore Eye Research InstituteSingapore National Eye CentreSingapore CitySingapore
- Ophthalmology and Visual Sciences Academic Clinical ProgramDuke‐NUS Medical SchoolSingapore CitySingapore
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingapore CitySingapore
- Institute of Molecular and Clinical OphthalmologyBaselSwitzerland
| | - Gerhard Garhöfer
- Department of Clinical PharmacologyMedical University of ViennaViennaAustria
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Gerhard G, Chua J, Tan B, Wong D, Schmidl D, Schmetterer L. Retinal Neurovascular Coupling in Diabetes. J Clin Med 2020; 9:jcm9092829. [PMID: 32882896 PMCID: PMC7565465 DOI: 10.3390/jcm9092829] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 12/15/2022] Open
Abstract
Neurovascular coupling, also termed functional hyperemia, is one of the physiological key mechanisms to adjust blood flow in a neural tissue in response to functional activity. In the retina, increased neural activity, such as that induced by visual stimulation, leads to the dilatation of retinal arterioles, which is accompanied by an immediate increase in retinal and optic nerve head blood flow. According to the current scientific view, functional hyperemia ensures the adequate supply of nutrients and metabolites in response to the increased metabolic demand of the neural tissue. Although the molecular mechanisms behind neurovascular coupling are not yet fully elucidated, there is compelling evidence that this regulation is impaired in a wide variety of neurodegenerative and vascular diseases. In particular, it has been shown that the breakdown of the functional hyperemic response is an early event in patients with diabetes. There is compelling evidence that alterations in neurovascular coupling precede visible signs of diabetic retinopathy. Based on these observations, it has been hypothesized that a breakdown of functional hyperemia may contribute to the retinal complications of diabetes such as diabetic retinopathy or macular edema. The present review summarizes the current evidence of impaired neurovascular coupling in patients with diabetes. In this context, the molecular mechanisms of functional hyperemia in health and disease will be covered. Finally, we will also discuss how neurovascular coupling may in future be used to monitor disease progression or risk stratification.
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Affiliation(s)
- Garhöfer Gerhard
- Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria; (G.G.); (D.S.)
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
| | - Damon Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria; (G.G.); (D.S.)
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria; (G.G.); (D.S.)
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
- Institute for Health Technologies, Nanyang Technological University, Singapore 308232, Singapore
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, 1090 Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, CH-4031 Basel, Switzerland
- Correspondence: ; Tel.: +43-1-40400-29810
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Retinal microvasculature and masked hypertension in young adults: the African-PREDICT study. Hypertens Res 2020; 43:1231-1238. [PMID: 32555326 DOI: 10.1038/s41440-020-0487-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 05/06/2020] [Accepted: 05/09/2020] [Indexed: 11/08/2022]
Abstract
Masked hypertension is known to induce microvascular complications. However, it is unclear whether early microvascular changes are already occurring in young, otherwise healthy adults. We therefore investigated whether retinal microvascular calibers and acute responses to a flicker stimulus are related to masked hypertension. We used the baseline data of 889 participants aged 20-30 years who were taking part in the African Prospective study on the Early Detection and Identification of Cardiovascular Disease and Hypertension. Clinic and 24-h ambulatory blood pressure were measured. The central retinal artery equivalent (CRAE) and central retinal vein equivalent were calculated from fundus images, and retinal vessel dilation was determined in response to flicker light-induced provocation. A smaller CRAE was observed in those with masked hypertension vs. those with normotension (157.1 vs. 161.2 measuring units, P < 0.001). In forward multivariable-adjusted regression analysis, only CRAE was negatively related to masked hypertension [adjusted R2 = 0.267, β = -0.097 (95% CI = -0.165; -0.029), P = 0.005], but other retinal microvascular parameters were not associated with masked hypertension. In multivariable logistic regression analyses, masked hypertension [OR = 2.333, (95% CI = 1.316; 4.241), P = 0.004] was associated with a narrower CRAE. In young healthy adults, masked hypertension was associated with retinal arteriolar narrowing, thereby reflecting early microvascular alterations known to predict cardiovascular outcomes in later life.
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Ahiante BO, Smith W, Lammertyn L, Schutte AE. Leptin and the Retinal Microvasculature in Young Black and White Adults: The African-PREDICT Study. Heart Lung Circ 2020; 29:1823-1831. [PMID: 32622912 DOI: 10.1016/j.hlc.2020.05.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/14/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Leptin is a vasoactive peptide that has been linked to diseases associated with macrovascular deterioration. What is still uncertain is its involvement in the microvasculature. Since microvascular changes are presumed to precede macrovascular deterioration, we examined whether measures of the retinal microvasculature are associated with leptin in healthy, young Black and White individuals. METHOD We included 283 Black and 289 White men and women (aged 20-30 years). We determined serum leptin, calculated central retinal artery and vein equivalents and arterio-venous ratio. We also measured retinal vessel responses to light flicker provocation. RESULTS Black men were leaner and had lower leptin than White men, whereas Black women had increased adiposity and leptin compared to White women (all p<0.001). Black groups had narrower retinal arteries, and greater maximum arteriolar and venular dilations in response to light flicker than the White groups (p<0.001). Arterio-venous ratio associated negatively with leptin (all p≤0.044) in all groups (except Black women), but was lost upon adjustment for body mass index and other covariates. We found an inverse association between maximal venular dilation and leptin only in Black men in single and multiple regression analyses (Std β= -0.22; R2=0.05; p=0.035). No associations were found between other retinal measures with leptin in the other groups. CONCLUSION We found an independent, negative association between retinal vein dilation with leptin in healthy, young Black men, suggesting a potential detrimental role for leptin in regulating microvascular responses in a population group known to be at greater risk of cardiovascular disease development.
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Affiliation(s)
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Leandi Lammertyn
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Aletta Elisabeth Schutte
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; School of Public Health and Community Medicine, University of New South Wales, The George Institute for Global Health, Sydney, Australia.
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Wentzel A, Malan L, von Känel R, Smith W, Malan NT. Heart rate variability, the dynamic nature of the retinal microvasculature and cardiac stress: providing insight into the brain-retina-heart link: the SABPA study. Eye (Lond) 2020; 34:835-846. [PMID: 31278382 PMCID: PMC7182573 DOI: 10.1038/s41433-019-0515-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/15/2019] [Accepted: 06/14/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND AIMS Decreased heart-rate-variability (HRV) indicates increased sympathetic nervous system (SNS) activity and modulation with a shift in the sympatho-vagal balance towards SNS predominance. Increased SNS activity may precede volume-loading hypertension, contribute to increases in cardiac troponin T (cTnT), endothelial dysfunction and small vessel disease. Therefore, we investigated the retinal vasculature, HRV during flicker-light-induced-provocation (FLIP) and systemic cTnT, a marker of cardiac stress, to provide further evidence in support of the brain-retina-heart link. METHODS Cross-sectional observations were obtained from a bi-ethnic cohort (N = 264), aged 23-68 years. Fasting serum samples for cTnT were obtained. Retinal vascular calibres were quantified from mydriatic eye fundus images and dynamic retinal vessel calibre responses were determined during FLIP. Time-and frequency domain parameters of HRV were calculated during FLIP for each participant. RESULTS Africans had wider venules and attenuated time domain parameters during FLIP. In Africans, inverse associations emerged between arteriolar dilation and both cTnT and root-mean squared of the standard deviations of successive RR-intervals (rMSSD) (p = 0.030), and between arteriolar constriction and both low-frequency expressed in normalised units (LFnu) (p = 0.003) and high-frequency expressed in normalised units (p = 0.021). Wider venules inversely associated with standard deviation of the NN intervals (SDNN) as well as LFnu (p = 0.009) in Africans. An opposite profile was observed in Caucasians with both time-and frequency domain parameters of HRV in relation to retinal vessel structure and function. CONCLUSION FLIP elicited increased SNS activity and modulation in this bi-ethnic cohort. In Africans, decreased HRV during FLIP accompanied arteriolar and venular responses and elevated systemic levels of cTnT, implying that the SNS exerted a significant effect on the smooth muscle tone of the retinal vasculature. Disrupted retinal autoregulation may imply general autonomic nervous system dysfunction; exemplifying central control by the brain on all systemic regulatory functions, across different vascular beds.
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Affiliation(s)
- Annemarie Wentzel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
| | - Leoné Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
| | - Roland von Känel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
- Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
- South African Medical Research Council, Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Nicolaas T Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
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Shu L, Liang J, Xun W, Yang H, Lu T. Prediction for the Total MRI Burden of Cerebral Small Vessel Disease With Retinal Microvascular Abnormalities in Ischemic Stroke/TIA Patients. Front Neurol 2020; 11:268. [PMID: 32373049 PMCID: PMC7177024 DOI: 10.3389/fneur.2020.00268] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 03/20/2020] [Indexed: 12/13/2022] Open
Abstract
Background and Purpose: The association of retinal microvascular abnormalities with the total cerebral small vessel disease (cSVD) burden found on brain MRI has not been determined. In the present study, we examined whether the retinopathy score could predict the total cSVD burden in ischemic stroke/transient ischemic attack (TIA) patients. A simple practical diagnostic tool may help identify candidates for MRI screening. Methods: We consecutively collected clinical data including retinal photography and cerebral MRI of ischemic stroke/TIA patients from August 2016 to August 2017 at our stroke center. The retinopathy score was assessed by the Keith-Wagener-Barker grading system for analyzing retinal microvascular abnormalities. To evaluate the total cSVD burden, the total cSVD score was assessed by awarding one point for the presence of each marker of cSVD on MRI. The clinical characteristics and retinopathy score were analyzed across patients for each total cSVD score. The association between the retinopathy score and the total cSVD score was analyzed. Results: Among the 263 enrolled patients, the frequency of hypertension in patients with a total cSVD score of 2, 3, or 4 was higher than that in patients with a score of 0 (69.5, 71.7, and 89.2% vs. 45.2% respectively, all P < 0.05). The retinopathy score was related to the total cSVD score (r = 0.687, P < 0.001). Adjusted multivariate ordinal regression showed that the retinopathy score was independently correlated with the total cSVD score (odds ratio [OR], 4.18; 95% confidence interval [CI], 3.07–5.70) after adjustment for age, history of hypertension, previous stroke/TIA and current smoking. The c statistics were 0.30 (95% CI, 0.24–0.37; P < 0.05), 0.46 (95% CI, 0.39–0.53; P = 0.303), 0.79 (95% CI, 0.72–0.86; P < 0.001), and 0.81 (95% CI, 0.74–0.88; P < 0.001) for predicting the total cSVD score of 1, 2, 3, and 4 respectively. Conclusions: These results suggest that retinal microvascular abnormalities have predictive value for severe total cSVD burden in ischemic stroke/TIA patients.
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Affiliation(s)
- Liming Shu
- Department of Neurology, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China.,Department of Neurology and Stroke Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jiahui Liang
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Weiquan Xun
- Department of Neurology and Stroke Center, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, China
| | - Hong Yang
- Department of Neurology and Stroke Center, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, China
| | - Tao Lu
- Department of Neurology and Stroke Center, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, China
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Sabel BA, Thut G, Haueisen J, Henrich-Noack P, Herrmann CS, Hunold A, Kammer T, Matteo B, Sergeeva EG, Waleszczyk W, Antal A. Vision modulation, plasticity and restoration using non-invasive brain stimulation – An IFCN-sponsored review. Clin Neurophysiol 2020; 131:887-911. [DOI: 10.1016/j.clinph.2020.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 12/18/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
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Malan L, Hamer M, von Känel R, van Wyk RD, Wentzel A, Steyn HS, van Vuuren P, Malan NT. Retinal-glia ischemia and inflammation induced by chronic stress: The SABPA study. Brain Behav Immun Health 2020; 2:100027. [PMID: 38377420 PMCID: PMC8474432 DOI: 10.1016/j.bbih.2019.100027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/14/2019] [Accepted: 12/15/2019] [Indexed: 01/10/2023] Open
Abstract
Background Psychobiological processes linking stress and vascular diseases remain poorly understood. The retina and the brain share a common embryonic-diencephalon origin and blood-barrier physiology e.g. ongoing ischemia facilitates S100B release with astrocytic activity and glial-fibrillary-acidic-protein expression (GFAP). However, GFAP decreases revealed astrocyte pathology in the prefrontal cortex of depression/suicide cases; and might be a key mechanism in stress - disease pathways. Methods A chronic emotional stress phenotype independent of age, ethnicity or sex was used to stratify the current prospective cohort (N = 359; aged 46 ± 9 years) into Stress (N = 236) and no-Stress groups (N = 123). Prospective data for glia ischemia risk markers were obtained, including 24 h BP, fasting S100B, GFAP, HbA1C and tumor-necrosis-factor-α (TNF-α). At 3-yr follow-up: diastolic-ocular-perfusion-pressure (indicating hypo-perfusion risk) was measured and retinal vessel calibers were quantified from digital images in the mydriatic eye. Results Higher hypertension (75% vs. 16%), diabetes (13% vs. 0%) and retinopathy (57% vs. 45%) prevalence was observed in Stress compared to no-Stress individuals. Stressed individuals had consistently raised S100B, TNF-α, HbA1C and higher diastolic-ocular-perfusion-pressure, but decreases in GFAP and GFAP:S100B. Furthermore stroke risk markers, arterial narrowing and venous widening were associated with consistently raised S100B, GFAP:S100B (p = 0.060), TNF-α and higher diastolic-ocular-perfusion-pressure [Adj. R2 0.39-0.41, p ≤ 0.05]. No retinal-glia associations were evident in the no-Stress group. Conclusions Retinal-glia ischemia and inflammation was induced by chronic stress. Persistent higher inflammation and S100B with GFAP decreases further reflected stress-induced astrocyte pathology in the human retina. It is recommended to increase awareness on chronic stress and susceptibility for brain ischemia.
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Affiliation(s)
- Leoné Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, 2520, South Africa
| | - Mark Hamer
- Division Surgery & Interventional Science, University College London, United Kingdom
| | - Roland von Känel
- Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, University Hospital Zurich, 8091, Switzerland
| | - Roelof D. van Wyk
- Surgical Ophthalmologist, 85 Peter Mokaba Street, Potchefstroom, 2531, South Africa
| | - Annemarie Wentzel
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, 2520, South Africa
| | - Hendrik S. Steyn
- Statistical Consultation Services, North-West University, Potchefstroom, 2520, South Africa
| | - Pieter van Vuuren
- School of Electrical, Electronic and Computer Engineering, North-West University, Potchefstroom, 2520, South Africa
| | - Nico T. Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, 2520, South Africa
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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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Strauss-Kruger M, Smith W, Wei W, Bagrov AY, Fedorova OV, Schutte AE. Microvascular function in non-dippers: Potential involvement of the salt sensitivity biomarker, marinobufagenin-The African-PREDICT study. J Clin Hypertens (Greenwich) 2019; 22:86-94. [PMID: 31873989 DOI: 10.1111/jch.13767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/20/2019] [Accepted: 12/02/2019] [Indexed: 12/01/2022]
Abstract
Suppressed nighttime blood pressure dipping is associated with salt sensitivity and may increase the hemodynamic load on the microvasculature. The mechanism remains unknown whereby salt sensitivity may increase the cardiovascular risk of non-dippers. Marinobufagenin, a novel steroidal biomarker, is associated with salt sensitivity and other cardiovascular risk factors independent of blood pressure. The authors investigated whether microvascular function in non-dippers is associated with marinobufagenin. The authors included 220 dippers and 154 non-dippers (aged 20-30 years) from the African-PREDICT study, with complete 24-hour urinary marinobufagenin and sodium data. The authors determined dipping status using 24-hour blood pressure monitoring and defined nighttime non-dipping <10%. The authors measured microvascular reactivity as retinal artery dilation in response to light flicker provocation. Young healthy non-dippers and dippers presented with similar peak retinal artery dilation, urinary sodium, and MBG excretion (P > .05). However, only in non-dippers did peak retinal artery dilation relate negatively to marinobufagenin excretion after single (r = -0.20; P = .012), partial (r = -0.23; P = .004), and multivariate-adjusted regression analyses (Adj. R2 = 0.34; β = -0.26; P < .001). The authors also noted a relationship between peak artery dilation and estimated salt intake (Adj. R2 = 0.30; β = -0.14; P = .051), but it was lost upon inclusion of marinobufagenin (Adj. R2 = 0.33; β = -0.015; P = .86). No relationship between microvascular reactivity and marinobufagenin was evident in dippers (P = .77). Marinobufagenin, representing salt sensitivity, may be involved in early microvascular functional changes in young non-dippers and thus contributes to the development of hypertension and cardiovascular disease later in life.
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Affiliation(s)
- Michél Strauss-Kruger
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa
| | - Wayne Smith
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.,Hypertension and Cardiovascular Disease, MRC Research Unit, North-West University, Potchefstroom, South Africa
| | - Wen Wei
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Alexei Y Bagrov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, Russia
| | - Olga V Fedorova
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Aletta E Schutte
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.,Hypertension and Cardiovascular Disease, MRC Research Unit, North-West University, Potchefstroom, South Africa
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Wood T, Nance E. Disease-directed engineering for physiology-driven treatment interventions in neurological disorders. APL Bioeng 2019; 3:040901. [PMID: 31673672 PMCID: PMC6811362 DOI: 10.1063/1.5117299] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/02/2019] [Indexed: 02/06/2023] Open
Abstract
Neurological disease is killing us. While there have long been attempts to develop therapies for both acute and chronic neurological diseases, no current treatments are curative. Additionally, therapeutic development for neurological disease takes 15 years and often costs several billion dollars. More than 96% of these therapies will fail in late stage clinical trials. Engineering novel treatment interventions for neurological disease can improve outcomes and quality of life for millions; however, therapeutics should be designed with the underlying physiology and pathology in mind. In this perspective, we aim to unpack the importance of, and need to understand, the physiology of neurological disease. We first dive into the normal physiological considerations that should guide experimental design, and then assess the pathophysiological factors of acute and chronic neurological disease that should direct treatment design. We provide an analysis of a nanobased therapeutic intervention that proved successful in translation due to incorporation of physiology at all stages of the research process. We also provide an opinion on the importance of keeping a high-level view to designing and administering treatment interventions. Finally, we close with an implementation strategy for applying a disease-directed engineering approach. Our assessment encourages embracing the complexity of neurological disease, as well as increasing efforts to provide system-level thinking in our development of therapeutics for neurological disease.
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Streese L, Kotliar K, Deiseroth A, Infanger D, Gugleta K, Schmaderer C, Hanssen H. Retinal endothelial function in cardiovascular risk patients: A randomized controlled exercise trial. Scand J Med Sci Sports 2019; 30:272-280. [DOI: 10.1111/sms.13560] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 09/18/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Lukas Streese
- Department of Sport, Exercise and Health Medical Faculty University of Basel Basel Switzerland
| | - Konstantin Kotliar
- Department of Medical Engineering and Applied Mathematics University of Applied Sciences Aachen Germany
| | - Arne Deiseroth
- Department of Sport, Exercise and Health Medical Faculty University of Basel Basel Switzerland
| | - Denis Infanger
- Department of Sport, Exercise and Health Medical Faculty University of Basel Basel Switzerland
| | | | - Christoph Schmaderer
- Department of Nephrology Klinikum rechts der Isar Technical University Munich Munich Germany
| | - Henner Hanssen
- Department of Sport, Exercise and Health Medical Faculty University of Basel Basel Switzerland
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Smith W, Kotliar KE, Lammertyn L, Ramoshaba NE, Vilser W, Huisman HW, Schutte AE. Retinal vessel caliber and caliber responses in true normotensive black and white adults: The African-PREDICT study. Microvasc Res 2019; 128:103937. [PMID: 31644892 DOI: 10.1016/j.mvr.2019.103937] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 07/20/2019] [Accepted: 10/12/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE Globally, a detrimental shift in cardiovascular disease risk factors and a higher mortality level are reported in some black populations. The retinal microvasculature provides early insight into the pathogenesis of systemic vascular diseases, but it is unclear whether retinal vessel calibers and acute retinal vessel functional responses differ between young healthy black and white adults. METHODS We included 112 black and 143 white healthy normotensive adults (20-30 years). Retinal vessel calibers (central retinal artery and vein equivalent (CRAE and CRVE)) were calculated from retinal images and vessel caliber responses to flicker light induced provocation (FLIP) were determined. Additionally, ambulatory blood pressure (BP), anthropometry and blood samples were collected. RESULTS The groups displayed similar 24 h BP profiles and anthropometry (all p > .24). Black participants demonstrated a smaller CRAE (158 ± 11 vs. 164 ± 11 MU, p < .001) compared to the white group, whereas CRVE was similar (p = .57). In response to FLIP, artery maximal dilation was greater in the black vs. white group (5.6 ± 2.1 vs. 3.3 ± 1.8%; p < .001). CONCLUSIONS Already at a young age, healthy black adults showed narrower retinal arteries relative to the white population. Follow-up studies are underway to show if this will be related to increased risk for hypertension development. The reason for the larger vessel dilation responses to FLIP in the black population is unclear and warrants further investigation.
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Affiliation(s)
- Wayne Smith
- Hypertension in Africa Research Team, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa.
| | - Konstantin E Kotliar
- Department of Biomedical Engineering and Technomathematics, Aachen University of Applied Sciences, Juelich, Germany
| | - Leandi Lammertyn
- Hypertension in Africa Research Team, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Nthai E Ramoshaba
- Hypertension in Africa Research Team, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | | | - Hugo W Huisman
- Hypertension in Africa Research Team, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - Aletta E Schutte
- Hypertension in Africa Research Team, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa; Medical Research Council: Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
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Streese L, Kotliar K, Deiseroth A, Infanger D, Vilser W, Hanssen H. Retinal Endothelial Function, Physical Fitness and Cardiovascular Risk: A Diagnostic Challenge. Front Physiol 2019; 10:831. [PMID: 31333489 PMCID: PMC6624470 DOI: 10.3389/fphys.2019.00831] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/17/2019] [Indexed: 01/10/2023] Open
Abstract
INTRODUCTION Dynamic retinal vessel analysis (DVA) is a new non-invasive method to quantify microvascular endothelial dysfunction by flicker light-induced dilatation (FID). FID has been shown to be impaired in type 2 diabetes as well as heart failure. The aim of the study was to analyze FID in healthy active versus healthy sedentary and cardiovascular (CV) risk patients in addition to corresponding static vessel diameters. METHODS Thirty-one healthy active (HA, mean age 60 ± 8 years), 33 healthy sedentary individuals (HS, 59 ± 7 years) and 76 sedentary patients with increased CV risk (SR, 58 ± 6 years) were included in this cross-sectional study. Group differences in CV risk factors and cardiorespiratory fitness, maximal arteriolar (ADmax) and venular (VDmax) dilatation as well as the arteriolar (AFarea) and venular (VFarea) area under the flicker curve were analyzed. The central retinal arteriolar and venular diameters were used to calculate the arteriolar-to-venular diameter ratio (AVR). RESULTS HS [ADmax = 3.5 (2.1)%; AFarea = 48.2 (31.9)%∗s] showed higher FID compared to SR [ADmax = 2.7 (1.8)%, p = 0.021; AFarea = 34.5 (26.5)%∗s, p = 0.006] and HA [AFarea = 32.8 (23.1)%∗s, p = 0.029]. HA and SR did not significantly differ. HA had a higher AVR (0.87 ± 0.05) compared to HS (0.83 ± 0.04, p < 0.001) with further deterioration in SR (0.79 ± 0.05, p < 0.001). Interestingly, 28 participants had impaired FID but normal AVR and 43 participants had normal FID but impaired AVR. DISCUSSION FID can differentiate between sedentary low and high risk individuals. However, FID in healthy active persons (HA) seemed impaired with a concomitant higher AVR. We postulate that lower FID in HA may be explained by predilatated arterioles and a reduced dilatation reserve. We recommend combination of FID with analysis of retinal vessel diameters to differentiate functional non-responders from manifest microvascular endothelial dysfunction and, thereby, improve microvascular risk stratification in a personalized medicine approach. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov: NCT02796976 (https://clinicaltrials.gov/ ct2/show/NCT02796976).
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Affiliation(s)
- Lukas Streese
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
| | - Konstantin Kotliar
- Department of Medical Engineering and Applied Mathematics, FH Aachen – University of Applied Sciences, Aachen, Germany
| | - Arne Deiseroth
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
| | - Denis Infanger
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
| | - Walthard Vilser
- Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany
| | - Henner Hanssen
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
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