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Deissler HL, Rehak M, Lytvynchuk L. VEGF-A 165a and angiopoietin-2 differently affect the barrier formed by retinal endothelial cells. Exp Eye Res 2024:110062. [PMID: 39187056 DOI: 10.1016/j.exer.2024.110062] [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: 04/09/2024] [Revised: 07/25/2024] [Accepted: 08/23/2024] [Indexed: 08/28/2024]
Abstract
Exposure to VEGF-A165a over several days leads to a persistent dysfunction of the very tight barrier formed by immortalized endothelial cells of the bovine retina (iBREC). Elevated permeability of the barrier is indicated by low cell index values determined by electric cell-substrate impedance measurements, by lower amounts of claudin-1, and by disruption of the homogenous and continuous staining of vascular endothelial cadherin at the plasma membrane. Because of findings that suggest modulation of VEGF-A's detrimental effects on the inner blood-retina barrier by the angiogenic growth factor angiopoietin-2, we investigated in more detail in vitro whether this growth factor indeed changes the stability of the barrier formed by retinal endothelial cells or modulates effects of VEGF-A. In view of the clinical relevance of anti-VEGF therapy, we also studied whether blocking VEGF-A-driven signaling is sufficient to prevent barrier dysfunction induced by a combination of both growth factors. Although angiopoietin-2 stimulated proliferation of iBREC, the formed barrier was not weakened at a concentration of 3 nM: Cell index values remained high and expression or subcellular localization of claudin-1 and vascular endothelial cadherin, respectively, were not affected. Angiopoietin-2 enhanced the changes induced by VEGF-A165a and this was more pronounced at lower concentrations of VEGF-A165a. Specific inhibition of the VEGF receptors with tivozanib as well as interfering with binding of VEGF-A to its receptors with bevacizumab prevented the detrimental effects of the growth factors; dual binding of angiopoietin-2 and VEGF-A by faricimab was marginally more efficient. Uptake of extracellular angiopoietin-2 by iBREC can be efficiently prevented by addition of faricimab which is also internalized by the cells. Exposure of the cells to faricimab over several days stabilized their barrier, confirming that inhibition of VEGF-A signaling is not harmful to this cell type. Taken together, our results confirm the dominant role of VEGF-A165a in processes resulting in increased permeability of retinal endothelial cells in which angiopoietin-2 might play a minor modulating role.
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Affiliation(s)
- Heidrun L Deissler
- Department of Ophthalmology, Justus Liebig University Giessen, Giessen, Germany.
| | - Matus Rehak
- Department of Ophthalmology, Justus Liebig University Giessen, Giessen, Germany; Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Lyubomyr Lytvynchuk
- Department of Ophthalmology, Justus Liebig University Giessen, Giessen, Germany.
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2
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Larionov A, Hammer CM, Fiedler K, Filgueira L. Dynamics of Endothelial Cell Diversity and Plasticity in Health and Disease. Cells 2024; 13:1276. [PMID: 39120307 PMCID: PMC11312403 DOI: 10.3390/cells13151276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 07/19/2024] [Accepted: 07/19/2024] [Indexed: 08/10/2024] Open
Abstract
Endothelial cells (ECs) are vital structural units of the cardiovascular system possessing two principal distinctive properties: heterogeneity and plasticity. Endothelial heterogeneity is defined by differences in tissue-specific endothelial phenotypes and their high predisposition to modification along the length of the vascular bed. This aspect of heterogeneity is closely associated with plasticity, the ability of ECs to adapt to environmental cues through the mobilization of genetic, molecular, and structural alterations. The specific endothelial cytoarchitectonics facilitate a quick structural cell reorganization and, furthermore, easy adaptation to the extrinsic and intrinsic environmental stimuli, known as the epigenetic landscape. ECs, as universally distributed and ubiquitous cells of the human body, play a role that extends far beyond their structural function in the cardiovascular system. They play a crucial role in terms of barrier function, cell-to-cell communication, and a myriad of physiological and pathologic processes. These include development, ontogenesis, disease initiation, and progression, as well as growth, regeneration, and repair. Despite substantial progress in the understanding of endothelial cell biology, the role of ECs in healthy conditions and pathologies remains a fascinating area of exploration. This review aims to summarize knowledge and concepts in endothelial biology. It focuses on the development and functional characteristics of endothelial cells in health and pathological conditions, with a particular emphasis on endothelial phenotypic and functional heterogeneity.
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Affiliation(s)
- Alexey Larionov
- Faculty of Science and Medicine, Anatomy, University of Fribourg, Route Albert-Gockel 1, CH-1700 Fribourg, Switzerland; (C.M.H.); (L.F.)
| | - Christian Manfred Hammer
- Faculty of Science and Medicine, Anatomy, University of Fribourg, Route Albert-Gockel 1, CH-1700 Fribourg, Switzerland; (C.M.H.); (L.F.)
| | - Klaus Fiedler
- Independent Researcher, CH-1700 Fribourg, Switzerland;
| | - Luis Filgueira
- Faculty of Science and Medicine, Anatomy, University of Fribourg, Route Albert-Gockel 1, CH-1700 Fribourg, Switzerland; (C.M.H.); (L.F.)
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Szarka G, Ganczer A, Balogh M, Tengölics ÁJ, Futácsi A, Kenyon G, Pan F, Kovács-Öller T, Völgyi B. Gap junctions fine-tune ganglion cell signals to equalize response kinetics within a given electrically coupled array. iScience 2024; 27:110099. [PMID: 38947503 PMCID: PMC11214328 DOI: 10.1016/j.isci.2024.110099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/06/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024] Open
Abstract
Retinal ganglion cells (RGCs) summate inputs and forward a spike train code to the brain in the form of either maintained spiking (sustained) or a quickly decaying brief spike burst (transient). We report diverse response transience values across the RGC population and, contrary to the conventional transient/sustained scheme, responses with intermediary characteristics are the most abundant. Pharmacological tests showed that besides GABAergic inhibition, gap junction (GJ)-mediated excitation also plays a pivotal role in shaping response transience and thus visual coding. More precisely GJs connecting RGCs to nearby amacrine and RGCs play a defining role in the process. These GJs equalize kinetic features, including the response transience of transient OFF alpha (tOFFα) RGCs across a coupled array. We propose that GJs in other coupled neuron ensembles in the brain are also critical in the harmonization of response kinetics to enhance the population code and suit a corresponding task.
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Affiliation(s)
- Gergely Szarka
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
- SzKK Imaging Core Facility, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Alma Ganczer
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Márton Balogh
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Ádám Jonatán Tengölics
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Anett Futácsi
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
- SzKK Imaging Core Facility, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | | | - Feng Pan
- The Hong Kong Polytechnic University, Hong Kong, China
| | - Tamás Kovács-Öller
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
- SzKK Imaging Core Facility, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Béla Völgyi
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
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4
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van Noorden CJ, Yetkin-Arik B, Serrano Martinez P, Bakker N, van Breest Smallenburg ME, Schlingemann RO, Klaassen I, Majc B, Habic A, Bogataj U, Galun SK, Vittori M, Erdani Kreft M, Novak M, Breznik B, Hira VV. New Insights in ATP Synthesis as Therapeutic Target in Cancer and Angiogenic Ocular Diseases. J Histochem Cytochem 2024; 72:329-352. [PMID: 38733294 PMCID: PMC11107438 DOI: 10.1369/00221554241249515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 04/01/2024] [Indexed: 05/13/2024] Open
Abstract
Lactate and ATP formation by aerobic glycolysis, the Warburg effect, is considered a hallmark of cancer. During angiogenesis in non-cancerous tissue, proliferating stalk endothelial cells (ECs) also produce lactate and ATP by aerobic glycolysis. In fact, all proliferating cells, both non-cancer and cancer cells, need lactate for the biosynthesis of building blocks for cell growth and tissue expansion. Moreover, both non-proliferating cancer stem cells in tumors and leader tip ECs during angiogenesis rely on glycolysis for pyruvate production, which is used for ATP synthesis in mitochondria through oxidative phosphorylation (OXPHOS). Therefore, aerobic glycolysis is not a specific hallmark of cancer but rather a hallmark of proliferating cells and limits its utility in cancer therapy. However, local treatment of angiogenic eye conditions with inhibitors of glycolysis may be a safe therapeutic option that warrants experimental investigation. Most types of cells in the eye such as photoreceptors and pericytes use OXPHOS for ATP production, whereas proliferating angiogenic stalk ECs rely on glycolysis for lactate and ATP production. (J Histochem Cytochem XX.XXX-XXX, XXXX).
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Affiliation(s)
- Cornelis J.F. van Noorden
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | - Bahar Yetkin-Arik
- Department of Pediatric Pulmonology, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
- Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht, The Netherlands
- Centre for Living Technologies, Alliance TU/e, WUR, UU, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Paola Serrano Martinez
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | - Noëlle Bakker
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | | | - Reinier O. Schlingemann
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
- Department of Ophthalmology, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
- Department of Ophthalmology, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, University of Lausanne, Lausanne, Switzerland
| | - Ingeborg Klaassen
- Ocular Angiogenesis Group, Amsterdam University Medical Center Location University of Amsterdam, Amsterdam, The Netherlands
| | - Bernarda Majc
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Anamarija Habic
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
- Jozef Stefan Postgraduate School, Ljubljana, Slovenia
| | - Urban Bogataj
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - S. Katrin Galun
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Milos Vittori
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Mateja Erdani Kreft
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Metka Novak
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Barbara Breznik
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Vashendriya V.V. Hira
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia
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5
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Grimes WN, Berson DM, Sabnis A, Hoon M, Sinha R, Tian H, Diamond JS. The retina's neurovascular unit: Müller glial sheaths and neuronal contacts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591885. [PMID: 38903067 PMCID: PMC11188116 DOI: 10.1101/2024.04.30.591885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The neurovascular unit (NVU), comprising vascular, glial and neural elements, supports the energetic demands of neural computation, but this aspect of the retina's trilaminar vessel network is poorly understood. Only the innermost vessel layer - the superficial vascular plexus (SVP) - is ensheathed by astrocytes, like brain capillaries, whereas glial ensheathment in other layers derives from radial Müller glia. Using serial electron microscopy reconstructions from mouse and primate retina, we find that Müller processes cover capillaries in a tessellating pattern, mirroring the tiled astrocytic endfeet wrapping brain capillaries. However, gaps in the Müller sheath, found mainly in the intermediate vascular plexus (IVP), permit different neuron types to contact pericytes and the endothelial cells directly. Pericyte somata are a favored target, often at spine-like structures with a reduced or absent vascular basement lamina. Focal application of adenosine triphosphate (ATP) to the vitreal surface evoked Ca2+ signals in Müller sheaths in all three vascular layers. Pharmacological experiments confirmed that Müller sheaths express purinergic receptors that, when activated, trigger intracellular Ca2+ signals that are amplified by IP3-controlled intracellular Ca2+ stores. When rod photoreceptors die in a mouse model of retinitis pigmentosa (rd10), Müller sheaths dissociate from the deep vascular plexus (DVP) but are largely unchanged within the IVP or SVP. Thus, Müller glia interact with retinal vessels in a laminar, compartmentalized manner: glial sheathes are virtually complete in the SVP but fenestrated in the IVP, permitting direct neural-to-vascular contacts. In the DVP, the glial sheath is only modestly fenestrated and is vulnerable to photoreceptor degeneration.
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Affiliation(s)
- William N. Grimes
- Synaptic Physiology Section, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, MD
| | - David M. Berson
- Department of Neuroscience, Brown University, Providence, RI
| | - Adit Sabnis
- Synaptic Physiology Section, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, MD
| | - Mrinalini Hoon
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI
| | - Raunak Sinha
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI
| | - Hua Tian
- Synaptic Physiology Section, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, MD
| | - Jeffrey S. Diamond
- Synaptic Physiology Section, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, MD
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6
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Feng L, Gao L. The role of neurovascular coupling dysfunction in cognitive decline of diabetes patients. Front Neurosci 2024; 18:1375908. [PMID: 38576869 PMCID: PMC10991808 DOI: 10.3389/fnins.2024.1375908] [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: 01/24/2024] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
Neurovascular coupling (NVC) is an important mechanism to ensure adequate blood supply to active neurons in the brain. NVC damage can lead to chronic impairment of neuronal function. Diabetes is characterized by high blood sugar and is considered an important risk factor for cognitive impairment. In this review, we provide fMRI evidence of NVC damage in diabetic patients with cognitive decline. Combined with the exploration of the major mechanisms and signaling pathways of NVC, we discuss the effects of chronic hyperglycemia on the cellular structure of NVC signaling, including key receptors, ion channels, and intercellular connections. Studying these diabetes-related changes in cell structure will help us understand the underlying causes behind diabetes-induced NVC damage and early cognitive decline, ultimately helping to identify the most effective drug targets for treatment.
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Affiliation(s)
| | - Ling Gao
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan, China
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7
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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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8
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Shrouder JJ, Calandra GM, Filser S, Varga DP, Besson-Girard S, Mamrak U, Dorok M, Bulut-Impraim B, Seker FB, Gesierich B, Laredo F, Wehn AC, Khalin I, Bayer P, Liesz A, Gokce O, Plesnila N. Continued dysfunction of capillary pericytes promotes no-reflow after experimental stroke in vivo. Brain 2024; 147:1057-1074. [PMID: 38153327 DOI: 10.1093/brain/awad401] [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: 03/17/2023] [Revised: 11/15/2023] [Accepted: 11/16/2023] [Indexed: 12/29/2023] Open
Abstract
Incomplete reperfusion of the microvasculature ('no-reflow') after ischaemic stroke damages salvageable brain tissue. Previous ex vivo studies suggest pericytes are vulnerable to ischaemia and may exacerbate no-reflow, but the viability of pericytes and their association with no-reflow remains under-explored in vivo. Using longitudinal in vivo two-photon single-cell imaging over 7 days, we showed that 87% of pericytes constrict during cerebral ischaemia and remain constricted post reperfusion, and 50% of the pericyte population are acutely damaged. Moreover, we revealed ischaemic pericytes to be fundamentally implicated in capillary no-reflow by limiting and arresting blood flow within the first 24 h post stroke. Despite sustaining acute membrane damage, we observed that over half of all cortical pericytes survived ischaemia and responded to vasoactive stimuli, upregulated unique transcriptomic profiles and replicated. Finally, we demonstrated the delayed recovery of capillary diameter by ischaemic pericytes after reperfusion predicted vessel reconstriction in the subacute phase of stroke. Cumulatively, these findings demonstrate that surviving cortical pericytes remain both viable and promising therapeutic targets to counteract no-reflow after ischaemic stroke.
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Affiliation(s)
- Joshua James Shrouder
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Gian Marco Calandra
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
| | - Severin Filser
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Core Research Facilities and Services-Light Microscope Facility, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Daniel Peter Varga
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Simon Besson-Girard
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Uta Mamrak
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
| | - Maximilian Dorok
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
| | - Buket Bulut-Impraim
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Fatma Burcu Seker
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Benno Gesierich
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Fabio Laredo
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
| | - Antonia Clarissa Wehn
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Department of Neurosurgery, LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
| | - Igor Khalin
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Normandie University, UNICAEN, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), GIP Cyceron, Institute Blood and Brain @ Caen-Normandie (BB@C), 14000 Caen, France
| | - Patrick Bayer
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
| | - Arthur Liesz
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Ozgun Gokce
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, Ludwig-Maximilians-University (LMU) Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
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9
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Erb C, Erb C, Kazakov A, Umetalieva M, Weisser B. Influence of Diabetes Mellitus on Glaucoma-Relevant Examination Results in Primary Open-Angle Glaucoma. Klin Monbl Augenheilkd 2024; 241:177-185. [PMID: 37643738 DOI: 10.1055/a-2105-0756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Primary open-angle glaucoma (POAG) is no longer considered an isolated eye pressure-dependent optic neuropathy, but a neurodegenerative disease in which oxidative stress and neuroinflammation are prominent. These processes may be exacerbated by additional systemic diseases. The most common are arterial hypertension, dyslipidemia, and diabetes mellitus. Using diabetes mellitus as an example, it will be shown how far-reaching the influence of such a systemic disease can be on both the functional and the structural diagnostic methods for POAG. This knowledge is essential, since these interferences can lead to misinterpretations of POAG, which can also affect therapeutic decisions.
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Affiliation(s)
- Carl Erb
- Augenklinik am Wittenbergplatz, Berlin, Deutschland
| | | | - Avaz Kazakov
- Department of External Relations and Development, Salymbekov University, Bishkek, Kyrgyzstan
| | - Maana Umetalieva
- Medical Faculty of Medicine, Salymbekov University, Bishkek, Kyrgyzstan
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10
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Huang BB, Fukuyama H, Burns SA, Fawzi AA. Imaging the Retinal Vascular Mural Cells In Vivo: Elucidating the Timeline of Their Loss in Diabetic Retinopathy. Arterioscler Thromb Vasc Biol 2024; 44:465-476. [PMID: 38152885 PMCID: PMC10842708 DOI: 10.1161/atvbaha.123.320169] [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: 09/15/2023] [Accepted: 12/13/2023] [Indexed: 12/29/2023]
Abstract
BACKGROUND Vascular mural cells (VMCs) are integral components of the retinal vasculature with critical homeostatic functions such as maintaining the inner blood-retinal barrier and vascular tone, as well as supporting the endothelial cells. Histopathologic donor eye studies have shown widespread loss of pericytes and smooth muscle cells, the 2 main VMC types, suggesting these cells are critical to the pathogenesis of diabetic retinopathy (DR). There remain, however, critical gaps in our knowledge regarding the timeline of VMC demise in human DR. METHODS In this study, we address this gap using adaptive optics scanning laser ophthalmoscopy to quantify retinal VMC density in eyes with no retinal disease (healthy), subjects with diabetes without diabetic retinopathy, and those with clinical DR and diabetic macular edema. We also used optical coherence tomography angiography to quantify capillary density of the superficial and deep capillary plexuses in these eyes. RESULTS Our results indicate significant VMC loss in retinal arterioles before the appearance of classic clinical signs of DR (diabetes without diabetic retinopathy versus healthy, 5.0±2.0 versus 6.5±2.0 smooth muscle cells per 100 µm; P<0.05), while a significant reduction in capillary VMC density (5.1±2.3 in diabetic macular edema versus 14.9±6.0 pericytes per 100 µm in diabetes without diabetic retinopathy; P=0.01) and capillary density (superficial capillary plexus vessel density, 37.6±3.8 in diabetic macular edema versus 45.5±2.4 in diabetes without diabetic retinopathy; P<0.0001) is associated with more advanced stages of clinical DR, particularly diabetic macular edema. CONCLUSIONS Our results offer a new framework for understanding the pathophysiologic course of VMC compromise in DR, which may facilitate the development and monitoring of therapeutic strategies aimed at VMC preservation and potentially the prevention of clinical DR and its associated morbidity. Imaging retinal VMCs provides an unparalleled opportunity to visualize these cells in vivo and may have wider implications in a range of diseases where these cells are disrupted.
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Affiliation(s)
- Bonnie B. Huang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Hisashi Fukuyama
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Department of Ophthalmology, Hyogo Medical University, Hyogo, Japan
| | | | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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11
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Jiang H, Liu B, Lin J, Xue T, Han Y, Lu C, Zhou S, Gu Y, Xu F, Shen Y, Xu L, Sun H. MuSCs and IPCs: roles in skeletal muscle homeostasis, aging and injury. Cell Mol Life Sci 2024; 81:67. [PMID: 38289345 PMCID: PMC10828015 DOI: 10.1007/s00018-023-05096-w] [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: 10/04/2023] [Revised: 12/01/2023] [Accepted: 12/17/2023] [Indexed: 02/01/2024]
Abstract
Skeletal muscle is a highly specialized tissue composed of myofibres that performs crucial functions in movement and metabolism. In response to external stimuli and injuries, a range of stem/progenitor cells, with muscle stem cells or satellite cells (MuSCs) being the predominant cell type, are rapidly activated to repair and regenerate skeletal muscle within weeks. Under normal conditions, MuSCs remain in a quiescent state, but become proliferative and differentiate into new myofibres in response to injury. In addition to MuSCs, some interstitial progenitor cells (IPCs) such as fibro-adipogenic progenitors (FAPs), pericytes, interstitial stem cells expressing PW1 and negative for Pax7 (PICs), muscle side population cells (SPCs), CD133-positive cells and Twist2-positive cells have been identified as playing direct or indirect roles in regenerating muscle tissue. Here, we highlight the heterogeneity, molecular markers, and functional properties of these interstitial progenitor cells, and explore the role of muscle stem/progenitor cells in skeletal muscle homeostasis, aging, and muscle-related diseases. This review provides critical insights for future stem cell therapies aimed at treating muscle-related diseases.
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Affiliation(s)
- Haiyan Jiang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
- Department of Emergency Medicine, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Boya Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Junfei Lin
- Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Tong Xue
- Department of Paediatrics, Medical School of Nantong University, Nantong University, Nantong, 226001, People's Republic of China
| | - Yimin Han
- Department of Paediatrics, Medical School of Nantong University, Nantong University, Nantong, 226001, People's Republic of China
| | - Chunfeng Lu
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, Nantong, 226001, Jiangsu, People's Republic of China
| | - Songlin Zhou
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Yun Gu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | - Feng Xu
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, Nantong, 226001, Jiangsu, People's Republic of China
| | - Yuntian Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
| | - Lingchi Xu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China.
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12
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Bonney SK, Nielson CD, Sosa MJ, Shih AY. Capillary regression leads to sustained local hypoperfusion by inducing constriction of upstream transitional vessels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.28.564529. [PMID: 37961686 PMCID: PMC10635020 DOI: 10.1101/2023.10.28.564529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In the brain, a microvascular sensory web coordinates oxygen delivery to regions of neuronal activity. This involves a dense network of capillaries that send conductive signals upstream to feeding arterioles to promote vasodilation and blood flow. Although this process is critical to the metabolic supply of healthy brain tissue, it may also be a point of vulnerability in disease. Deterioration of capillary networks is a hallmark of many neurological disorders and how this web is engaged during vascular damage remains unknown. We performed in vivo two-photon microscopy on young adult mural cell reporter mice and induced focal capillary injuries using precise two-photon laser irradiation of single capillaries. We found that ∼63% of the injuries resulted in regression of the capillary segment 7-14 days following injury, and the remaining repaired to re-establish blood flow within 7 days. Injuries that resulted in capillary regression induced sustained vasoconstriction in the upstream arteriole-capillary transition (ACT) zone at least 21 days post-injury in both awake and anesthetized mice. This abnormal vasoconstriction involved attenuation of vasomotor dynamics and uncoupling from mural cell calcium signaling following capillary regression. Consequently, blood flow was reduced in the ACT zone and in secondary, uninjured downstream capillaries. These findings demonstrate how capillary injury and regression, as often seen in age-related neurological disease, can impair the microvascular sensory web and contribute to cerebral hypoperfusion. SIGNIFICANCE Deterioration of the capillary network is a characteristic of many neurological diseases and can exacerbate neuronal dysfunction and degeneration due to poor blood perfusion. Here we show that focal capillary injuries can induce vessel regression and elicit sustained vasoconstriction in upstream transitional vessels that branch from cortical penetrating arterioles. This reduces blood flow to broader, uninjured regions of the same microvascular network. These findings suggest that widespread and cumulative damage to brain capillaries in neurological disease may broadly affect blood supply and contribute to hypoperfusion through their remote actions.
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13
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Bonnar O, Shaw K, Anderle S, Grijseels DM, Clarke D, Bell L, King SL, Hall CN. APOE4 expression confers a mild, persistent reduction in neurovascular function in the visual cortex and hippocampus of awake mice. J Cereb Blood Flow Metab 2023; 43:1826-1841. [PMID: 37350319 PMCID: PMC10676141 DOI: 10.1177/0271678x231172842] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 06/24/2023]
Abstract
Vascular factors are known to be early and important players in Alzheimer's disease (AD) development, however the role of the ε4 allele of the Apolipoprotein (APOE) gene (a risk factor for developing AD) remains unclear. APOE4 genotype is associated with early and severe neocortical vascular deficits in anaesthetised mice, but in humans, vascular and cognitive dysfunction are focused on the hippocampal formation and appear later. How APOE4 might interact with the vasculature to confer AD risk during the preclinical phase represents a gap in existing knowledge. To avoid potential confounds of anaesthesia and to explore regions most relevant for human disease, we studied the visual cortex and hippocampus of awake APOE3 and APOE4-TR mice using 2-photon microscopy of neurons and blood vessels. We found mild vascular deficits: vascular density and functional hyperaemia were unaffected in APOE4 mice, and neuronal or vascular function did not decrease up to late middle-age. Instead, vascular responsiveness was lower, arteriole vasomotion was reduced and neuronal calcium signals during visual stimulation were increased. This suggests that, alone, APOE4 expression is not catastrophic but stably alters neurovascular physiology. We suggest this state makes APOE4 carriers more sensitive to subsequent insults such as injury or beta amyloid accumulation.
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Affiliation(s)
| | | | - Silvia Anderle
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Dori M Grijseels
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Devin Clarke
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Laura Bell
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Sarah L King
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Catherine N Hall
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
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14
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Alarcon-Martinez L, Shiga Y, Villafranca-Baughman D, Cueva Vargas JL, Vidal Paredes IA, Quintero H, Fortune B, Danesh-Meyer H, Di Polo A. Neurovascular dysfunction in glaucoma. Prog Retin Eye Res 2023; 97:101217. [PMID: 37778617 DOI: 10.1016/j.preteyeres.2023.101217] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Retinal ganglion cells, the neurons that die in glaucoma, are endowed with a high metabolism requiring optimal provision of oxygen and nutrients to sustain their activity. The timely regulation of blood flow is, therefore, essential to supply firing neurons in active areas with the oxygen and glucose they need for energy. Many glaucoma patients suffer from vascular deficits including reduced blood flow, impaired autoregulation, neurovascular coupling dysfunction, and blood-retina/brain-barrier breakdown. These processes are tightly regulated by a community of cells known as the neurovascular unit comprising neurons, endothelial cells, pericytes, Müller cells, astrocytes, and microglia. In this review, the neurovascular unit takes center stage as we examine the ability of its members to regulate neurovascular interactions and how their function might be altered during glaucomatous stress. Pericytes receive special attention based on recent data demonstrating their key role in the regulation of neurovascular coupling in physiological and pathological conditions. Of particular interest is the discovery and characterization of tunneling nanotubes, thin actin-based conduits that connect distal pericytes, which play essential roles in the complex spatial and temporal distribution of blood within the retinal capillary network. We discuss cellular and molecular mechanisms of neurovascular interactions and their pathophysiological implications, while highlighting opportunities to develop strategies for vascular protection and regeneration to improve functional outcomes in glaucoma.
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Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada; Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Yukihiro Shiga
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Deborah Villafranca-Baughman
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Jorge L Cueva Vargas
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Isaac A Vidal Paredes
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Heberto Quintero
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Healthy, Portland, OR, USA
| | - Helen Danesh-Meyer
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada.
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15
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Kovács-Öller T, Szarka G, Hoffmann G, Péntek L, Valentin G, Ross L, Völgyi B. Extrinsic and Intrinsic Factors Determine Expression Levels of Gap Junction-Forming Connexins in the Mammalian Retina. Biomolecules 2023; 13:1119. [PMID: 37509155 PMCID: PMC10377540 DOI: 10.3390/biom13071119] [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: 06/23/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Gap junctions (GJs) are not static bridges; instead, GJs as well as the molecular building block connexin (Cx) proteins undergo major expression changes in the degenerating retinal tissue. Various progressive diseases, including retinitis pigmentosa, glaucoma, age-related retinal degeneration, etc., affect neurons of the retina and thus their neuronal connections endure irreversible changes as well. Although Cx expression changes might be the hallmarks of tissue deterioration, GJs are not static bridges and as such they undergo adaptive changes even in healthy tissue to respond to the ever-changing environment. It is, therefore, imperative to determine these latter adaptive changes in GJ functionality as well as in their morphology and Cx makeup to identify and distinguish them from alterations following tissue deterioration. In this review, we summarize GJ alterations that take place in healthy retinal tissue and occur on three different time scales: throughout the entire lifespan, during daily changes and as a result of quick changes of light adaptation.
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Affiliation(s)
- Tamás Kovács-Öller
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Gergely Szarka
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Gyula Hoffmann
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
| | - Loretta Péntek
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Gréta Valentin
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Liliana Ross
- Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Béla Völgyi
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
- Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary
- NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary
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16
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Benarroch E. What Are the Roles of Pericytes in the Neurovascular Unit and Its Disorders? Neurology 2023; 100:970-977. [PMID: 37188542 PMCID: PMC10186232 DOI: 10.1212/wnl.0000000000207379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/15/2023] [Indexed: 05/17/2023] Open
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17
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The Active Role of Pericytes During Neuroinflammation in the Adult Brain. Cell Mol Neurobiol 2023; 43:525-541. [PMID: 35195811 DOI: 10.1007/s10571-022-01208-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/13/2022] [Indexed: 12/11/2022]
Abstract
Microvessels in the central nervous system (CNS) have one of the highest populations of pericytes, indicating their crucial role in maintaining homeostasis. Pericytes are heterogeneous cells located around brain microvessels; they present three different morphologies along the CNS vascular tree: ensheathing, mesh, and thin-strand pericytes. At the arteriole-capillary transition ensheathing pericytes are found, while mesh and thin-strand pericytes are located at capillary beds. Brain pericytes are essential for the establishment and maintenance of the blood-brain barrier, which restricts the passage of soluble and potentially toxic molecules from the circulatory system to the brain parenchyma. Pericytes play a key role in regulating local inflammation at the CNS. Pericytes can respond differentially, depending on the degree of inflammation, by secreting a set of neurotrophic factors to promote cell survival and regeneration, or by potentiating inflammation through the release of inflammatory mediators (e.g., cytokines and chemokines), and the overexpression of cell adhesion molecules. Under inflammatory conditions, pericytes may regulate immune cell trafficking to the CNS and play a role in perpetuating local inflammation. In this review, we describe pericyte responses during acute and chronic neuroinflammation.
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18
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Traumatic Brain Injury Induces Microglial and Caspase3 Activation in the Retina. Int J Mol Sci 2023; 24:ijms24054451. [PMID: 36901880 PMCID: PMC10003323 DOI: 10.3390/ijms24054451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023] Open
Abstract
Traumatic brain injury (TBI) is among the main causes of sudden death after head trauma. These injuries can result in severe degeneration and neuronal cell death in the CNS, including the retina, which is a crucial part of the brain responsible for perceiving and transmitting visual information. The long-term effects of mild-repetitive TBI (rmTBI) are far less studied thus far, even though damage induced by repetitive injuries occurring in the brain is more common, especially amongst athletes. rmTBI can also have a detrimental effect on the retina and the pathophysiology of these injuries is likely to differ from severe TBI (sTBI) retinal injury. Here, we show how rmTBI and sTBI can differentially affect the retina. Our results indicate an increase in the number of activated microglial cells and Caspase3-positive cells in the retina in both traumatic models, suggesting a rise in the level of inflammation and cell death after TBI. The pattern of microglial activation appears distributed and widespread but differs amongst the various retinal layers. sTBI induced microglial activation in both the superficial and deep retinal layers. In contrast to sTBI, no significant change occurred following the repetitive mild injury in the superficial layer, only the deep layer (spanning from the inner nuclear layer to the outer plexiform layer) shows microglial activation. This difference suggests that alternate response mechanisms play a role in the case of the different TBI incidents. The Caspase3 activation pattern showed a uniform increase in both the superficial and deep layers of the retina. This suggests a different action in the course of the disease in sTBI and rmTBI models and points to the need for new diagnostic procedures. Our present results suggest that the retina might serve as such a model of head injuries since the retinal tissue reacts to both forms of TBI and is the most accessible part of the human brain.
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19
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Abstract
Pericytes, attached to the surface of capillaries, play an important role in regulating local blood flow. Using optogenetic tools and genetically encoded reporters in conjunction with confocal and multiphoton imaging techniques, the 3D structure, anatomical organization, and physiology of pericytes have recently been the subject of detailed examination. This work has revealed novel functions of pericytes and morphological features such as tunneling nanotubes in brain and tunneling microtubes in heart. Here, we discuss the state of our current understanding of the roles of pericytes in blood flow control in brain and heart, where functions may differ due to the distinct spatiotemporal metabolic requirements of these tissues. We also outline the novel concept of electro-metabolic signaling, a universal mechanistic framework that links tissue metabolic state with blood flow regulation by pericytes and vascular smooth muscle cells, with capillary KATP and Kir2.1 channels as primary sensors. Finally, we present major unresolved questions and outline how they can be addressed.
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Affiliation(s)
- Thomas A Longden
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Guiling Zhao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ashwini Hariharan
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - W Jonathan Lederer
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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20
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Ponce-Mora A, Yuste A, Perini-Villanueva G, Miranda M, Bejarano E. Connexins Biology in the Pathophysiology of Retinal Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:229-234. [PMID: 37440038 DOI: 10.1007/978-3-031-27681-1_33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Connexins (Cx) are a family of transmembrane proteins that form gap junction intercellular channels that connect neighboring cells. These channels allow the passage of ions and other biomolecules smaller than 1 kDa, thereby synchronizing the cells both electrically and metabolically. Cxs are expressed in all retinal cell types and the diversity of Cx isoforms involved in the assembly of the channels provides a functional syncytium required for visual transduction. In this chapter, we summarize the status of current knowledge regarding Cx biology in retinal tissues and discuss how Cx dysfunction is associated with retinal disease pathophysiology. Although the contribution of Cx deficiency to retinal degeneration is not well understood, recent findings present Cx as a potential therapeutic target. Therefore, we will briefly discuss pharmacological approaches and gene therapies that are being explored to modulate Cx function and fight sight-threatening eye diseases.
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Affiliation(s)
- Alejandro Ponce-Mora
- School of Health Sciences and Veterinary School, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Andrea Yuste
- School of Health Sciences and Veterinary School, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Giuliana Perini-Villanueva
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA
| | - María Miranda
- School of Health Sciences and Veterinary School, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Eloy Bejarano
- School of Health Sciences and Veterinary School, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain.
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21
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Morgan JIW, Chui TYP, Grieve K. Twenty-five years of clinical applications using adaptive optics ophthalmoscopy [Invited]. BIOMEDICAL OPTICS EXPRESS 2023; 14:387-428. [PMID: 36698659 PMCID: PMC9841996 DOI: 10.1364/boe.472274] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/22/2022] [Accepted: 11/27/2022] [Indexed: 05/02/2023]
Abstract
Twenty-five years ago, adaptive optics (AO) was combined with fundus photography, thereby initiating a new era in the field of ophthalmic imaging. Since that time, clinical applications of AO ophthalmoscopy to investigate visual system structure and function in both health and disease abound. To date, AO ophthalmoscopy has enabled visualization of most cell types in the retina, offered insight into retinal and systemic disease pathogenesis, and been integrated into clinical trials. This article reviews clinical applications of AO ophthalmoscopy and addresses remaining challenges for AO ophthalmoscopy to become fully integrated into standard ophthalmic care.
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Affiliation(s)
- Jessica I. W. Morgan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Contributed equally
| | - Toco Y. P. Chui
- Department of Ophthalmology, The New York Eye and Ear Infirmary of Mount Sinai, New York, NY 10003, USA
- Contributed equally
| | - Kate Grieve
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, and CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012 Paris, France
- Contributed equally
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22
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Hariharan A, Robertson CD, Garcia DCG, Longden TA. Brain capillary pericytes are metabolic sentinels that control blood flow through a K ATP channel-dependent energy switch. Cell Rep 2022; 41:111872. [PMID: 36577387 PMCID: PMC10187957 DOI: 10.1016/j.celrep.2022.111872] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 10/10/2022] [Accepted: 11/30/2022] [Indexed: 12/28/2022] Open
Abstract
Despite the abundance of capillary thin-strand pericytes and their proximity to neurons and glia, little is known of the contributions of these cells to the control of brain hemodynamics. We demonstrate that the pharmacological activation of thin-strand pericyte KATP channels profoundly hyperpolarizes these cells, dilates upstream penetrating arterioles and arteriole-proximate capillaries, and increases capillary blood flow. Focal stimulation of pericytes with a KATP channel agonist is sufficient to evoke this response, mediated via KIR2.1 channel-dependent retrograde propagation of hyperpolarizing signals, whereas genetic inactivation of pericyte KATP channels eliminates these effects. Critically, we show that decreasing extracellular glucose to less than 1 mM or inhibiting glucose uptake by blocking GLUT1 transporters in vivo flips a mechanistic energy switch driving rapid KATP-mediated pericyte hyperpolarization to increase local blood flow. Together, our findings recast capillary pericytes as metabolic sentinels that respond to local energy deficits by increasing blood flow to neurons to prevent energetic shortfalls.
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Affiliation(s)
- Ashwini Hariharan
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, USA; Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Colin D Robertson
- Department of Pharmacology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Daniela C G Garcia
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, USA; Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Thomas A Longden
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, USA; Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, School of Medicine, University of Maryland, Baltimore, MD, USA.
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23
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He S, Zhang Z, Peng X, Wu Y, Zhu Y, Wang L, Zhou H, Li T, Liu L. The protective effect of pericytes on vascular permeability after hemorrhagic shock and their relationship with Cx43. Front Physiol 2022; 13:948541. [PMID: 36262250 PMCID: PMC9576106 DOI: 10.3389/fphys.2022.948541] [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: 05/20/2022] [Accepted: 09/02/2022] [Indexed: 11/13/2022] Open
Abstract
Vascular hyperpermeability is a complication of hemorrhagic shock. Pericytes (PCs) are a group of mural cells surrounded by microvessels that are located on the basolateral side of the endothelium. Previous studies have shown that damage to PCs contributes to the occurrence of many diseases such as diabetic retinopathy and myocardial infarction. Whether PCs can protect the vascular barrier function following hemorrhagic shock and the underlying mechanisms are unknown. A hemorrhagic shock rat model, Cx43 vascular endothelial cell (VEC)-specific knockdown mice, and VECs were used to investigate the role of PCs in vascular barrier function and their relationship with Cx43. The results showed that following hemorrhagic shock, the number of PCs in the microvessels was significantly decreased and was negatively associated with an increase in pulmonary and mesenteric vascular permeability. Exogenous infusion of PCs (106 cells per rat) colonized the microvessels and improved pulmonary and mesenteric vascular barrier function. Upregulation of Cx43 in PCs significantly increased the number of PCs colonizing the pulmonary vessels. In contrast, downregulation of Cx43 expression in PCs or knockout of Cx43 in VECs (Cx43 KO mice) significantly reduced PC colonization in pulmonary vessels in vivo and reduced direct contact formation between PCs and VECs in vitro. It has been suggested that PCs have an important protective effect on vascular barrier function in pulmonary and peripheral vessels following hemorrhagic shock. Cx43 plays an important role in the colonization of exogenous PCs in the microvessels. This finding provides a potential new shock treatment measure.
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Affiliation(s)
- Shuangshuang He
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
- Department of Pharmacy, Army Medical Center, Army Medical University, Chongqing, China
| | - Zisen Zhang
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
| | - Xiaoyong Peng
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
| | - Yue Wu
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
| | - Yu Zhu
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
| | - Li Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
| | - Henan Zhou
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
| | - Tao Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
- *Correspondence: Tao Li, ; Liangming Liu,
| | - Liangming Liu
- State Key Laboratory of Trauma, Burns and Combined Injury, Shock and Transfusion Research Department, Army Medical Center, Army Medical University, Chongqing, China
- *Correspondence: Tao Li, ; Liangming Liu,
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24
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Eleftheriou CG, Corona C, Khattak S, Alam NM, Ivanova E, Bianchimano P, Liu Y, Sun D, Singh R, Batoki JC, Prusky GT, McAnany JJ, Peachey NS, Romano C, Sagdullaev BT. Retinoschisin Deficiency Induces Persistent Aberrant Waves of Activity Affecting Neuroglial Signaling in the Retina. J Neurosci 2022; 42:6983-7000. [PMID: 35906066 PMCID: PMC9464019 DOI: 10.1523/jneurosci.2128-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 07/18/2022] [Accepted: 07/22/2022] [Indexed: 11/21/2022] Open
Abstract
Genetic disorders that present during development make treatment strategies particularly challenging because there is a need to disentangle primary pathophysiology from downstream dysfunction caused at key developmental stages. To provide a deeper insight into this question, we studied a mouse model of X-linked juvenile retinoschisis, an early-onset inherited condition caused by mutations in the Rs1 gene encoding retinoschisin (RS1) and characterized by cystic retinal lesions and early visual deficits. Using an unbiased approach in expressing the fast intracellular calcium indicator GCaMP6f in neuronal, glial, and vascular cells of the retina of RS1-deficient male mice, we found that initial cyst formation is paralleled by the appearance of aberrant spontaneous neuroglial signals as early as postnatal day 15, when eyes normally open. These presented as glutamate-driven wavelets of neuronal activity and sporadic radial bursts of activity by Müller glia, spanning all retinal layers and disrupting light-induced signaling. This study confers a role to RS1 beyond its function as an adhesion molecule, identifies an early onset for dysfunction in the course of disease, establishing a potential window for disease diagnosis and therapeutic intervention.SIGNIFICANCE STATEMENT Developmental disorders make it difficult to distinguish pathophysiology due to ongoing disease from pathophysiology due to disrupted development. Here, we investigated a mouse model for X-linked retinoschisis, a well defined monogenic degenerative disease caused by mutations in the Rs1 gene, which codes for the protein retinoschisin. We evaluated the spontaneous activity of explanted retinas lacking retinoschisin at key stages of development using the unbiased approach of ubiquitously expressing GCaMP6f in all retinal neurons, vasculature, and glia. In mice lacking RS1, we found that an array of novel phenotypes, which present around eye opening, are linked to glutamatergic neurotransmission and affect visual processing. These data identify a novel pathophysiology linked to RS1, and define a window where treatments might be best targeted.
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Affiliation(s)
- Cyril G Eleftheriou
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Carlo Corona
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | | | - Nazia M Alam
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Elena Ivanova
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
| | - Paola Bianchimano
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Yang Liu
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
| | - Duo Sun
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
| | - Rupesh Singh
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Julia C Batoki
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Glen T Prusky
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - J Jason McAnany
- Department of Ophthalmology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
- Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio 44106
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio 44195
| | | | - Botir T Sagdullaev
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
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25
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Zhao H, Kong H, Wang W, Chen T, Zhang Y, Zhu J, Feng D, Cui Y. High Glucose Aggravates Retinal Endothelial Cell Dysfunction by Activating the RhoA/ROCK1/pMLC/Connexin43 Signaling Pathway. Invest Ophthalmol Vis Sci 2022; 63:22. [PMID: 35881407 PMCID: PMC9339693 DOI: 10.1167/iovs.63.8.22] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose This research aims to explore the mechanism underlying the relationship between RhoA/ROCK signaling and Connexin43 (Cx43) in retinal endothelial cell dysfunction and to evaluate the protective effect of ROCK inhibitors against retinal endothelial cell dysfunction in diabetic retinopathy (DR) models. Methods TUNEL staining, hematoxylin and eosin staining, a retinal digestion assay, and Evans blue assay were conducted to explore the effect of fasudil in alleviating retinal dysfunction induced by DR. ELISA, the CCK-8 assay, and flow cytometry were conducted to study inflammation, viability, and apoptosis of mouse retinal microvascular endothelial cells treated with high glucose and ROCK inhibitors. The qRT–PCR and Western blotting were used to evaluate the expression of RhoA, ROCK1, ROCK2, MLC, pMLC, and Cx43. Co-immunoprecipitation was used to verify the interaction between pMLC and Cx43. Immunofluorescence and scrape-loading and dye transfer were used to evaluate the expression and function of Cx43. Results Marked endothelial cell dysfunction resulting from the activation of RhoA/ROCK1 signaling was found in in vivo and in vitro models of DR. Via interaction with pMLC, which is downstream of RhoA/ROCK1, a significant downregulation of Cx43 was observed in retinal endothelial cells. Treatment with ROCK inhibitors ameliorated retinal endothelial dysfunction in vitro. The ROCK inhibitor, fasudil, significantly alleviated retinal dysfunction as shown by a decrease of retinal acellular capillaries, an improvement of vascular permeability, and a reduction of cell apoptosis in vivo. Conclusions Our study highlights a novel mechanism that high glucose could activate RhoA/ROCK1/pMLC signaling, which targets the expression and localization of Cx43 and is responsible for cell viability, apoptosis, and inflammation, resulting in retinal endothelial cell injury. ROCK inhibitors markedly ameliorate endothelial cell dysfunction, suggesting their therapeutic potential for diabetic retinopathy.
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Affiliation(s)
- Hongran Zhao
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China.,School of Medicine, Shandong University, Jinan, Shandong Province, China.,NHC Key Laboratory of Otorhinolaryngology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China.,Laboratory of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Hui Kong
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China.,Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China.,NHC Key Laboratory of Otorhinolaryngology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Wenjuan Wang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
| | - Tianran Chen
- School of Medicine, Shandong University, Jinan, Shandong Province, China
| | - Yuting Zhang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
| | - Jing Zhu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
| | - Dandan Feng
- Department of Cardiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, China
| | - Yan Cui
- Department of Ophthalmology, Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong Province, China
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26
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Guilbert J, Légaré A, De Koninck P, Desrosiers P, Desjardins M. Toward an integrative neurovascular framework for studying brain networks. NEUROPHOTONICS 2022; 9:032211. [PMID: 35434179 PMCID: PMC8989057 DOI: 10.1117/1.nph.9.3.032211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/11/2022] [Indexed: 05/28/2023]
Abstract
Brain functional connectivity based on the measure of blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signals has become one of the most widely used measurements in human neuroimaging. However, the nature of the functional networks revealed by BOLD fMRI can be ambiguous, as highlighted by a recent series of experiments that have suggested that typical resting-state networks can be replicated from purely vascular or physiologically driven BOLD signals. After going through a brief review of the key concepts of brain network analysis, we explore how the vascular and neuronal systems interact to give rise to the brain functional networks measured with BOLD fMRI. This leads us to emphasize a view of the vascular network not only as a confounding element in fMRI but also as a functionally relevant system that is entangled with the neuronal network. To study the vascular and neuronal underpinnings of BOLD functional connectivity, we consider a combination of methodological avenues based on multiscale and multimodal optical imaging in mice, used in combination with computational models that allow the integration of vascular information to explain functional connectivity.
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Affiliation(s)
- Jérémie Guilbert
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Université Laval, Centre de recherche du CHU de Québec, Québec, Canada
| | - Antoine Légaré
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Centre de recherche CERVO, Québec, Canada
- Université Laval, Department of Biochemistry, Microbiology, and Bioinformatics, Québec, Canada
| | - Paul De Koninck
- Centre de recherche CERVO, Québec, Canada
- Université Laval, Department of Biochemistry, Microbiology, and Bioinformatics, Québec, Canada
| | - Patrick Desrosiers
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Centre de recherche CERVO, Québec, Canada
| | - Michèle Desjardins
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Université Laval, Centre de recherche du CHU de Québec, Québec, Canada
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27
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Girolamo F, Errede M, Bizzoca A, Virgintino D, Ribatti D. Central Nervous System Pericytes Contribute to Health and Disease. Cells 2022; 11:1707. [PMID: 35626743 PMCID: PMC9139243 DOI: 10.3390/cells11101707] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 12/11/2022] Open
Abstract
Successful neuroprotection is only possible with contemporary microvascular protection. The prevention of disease-induced vascular modifications that accelerate brain damage remains largely elusive. An improved understanding of pericyte (PC) signalling could provide important insight into the function of the neurovascular unit (NVU), and into the injury-provoked responses that modify cell-cell interactions and crosstalk. Due to sharing the same basement membrane with endothelial cells, PCs have a crucial role in the control of endothelial, astrocyte, and oligodendrocyte precursor functions and hence blood-brain barrier stability. Both cerebrovascular and neurodegenerative diseases impair oxygen delivery and functionally impair the NVU. In this review, the role of PCs in central nervous system health and disease is discussed, considering their origin, multipotency, functions and also dysfunction, focusing on new possible avenues to modulate neuroprotection. Dysfunctional PC signalling could also be considered as a potential biomarker of NVU pathology, allowing us to individualize therapeutic interventions, monitor responses, or predict outcomes.
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Affiliation(s)
- Francesco Girolamo
- Unit of Human Anatomy and Histology, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari ‘Aldo Moro’, 70124 Bari, Italy; (M.E.); (D.V.); (D.R.)
| | - Mariella Errede
- Unit of Human Anatomy and Histology, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari ‘Aldo Moro’, 70124 Bari, Italy; (M.E.); (D.V.); (D.R.)
| | - Antonella Bizzoca
- Physiology Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari ‘Aldo Moro’, 70124 Bari, Italy;
| | - Daniela Virgintino
- Unit of Human Anatomy and Histology, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari ‘Aldo Moro’, 70124 Bari, Italy; (M.E.); (D.V.); (D.R.)
| | - Domenico Ribatti
- Unit of Human Anatomy and Histology, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari ‘Aldo Moro’, 70124 Bari, Italy; (M.E.); (D.V.); (D.R.)
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28
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Moccia F, Negri S, Faris P, Angelone T. Targeting endothelial ion signalling to rescue cerebral blood flow in cerebral disorders. Vascul Pharmacol 2022; 145:106997. [DOI: 10.1016/j.vph.2022.106997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/22/2022] [Accepted: 05/02/2022] [Indexed: 10/18/2022]
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29
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Beth Payne L, Tewari BP, Dunkenberger L, Bond S, Savelli A, Darden J, Zhao H, Willi C, Kanodia R, Gude R, Powell MD, Oestreich KJ, Sontheimer H, Dal-Pra S, Chappell JC. Pericyte Progenitor Coupling to the Emerging Endothelium During Vasculogenesis via Connexin 43. Arterioscler Thromb Vasc Biol 2022; 42:e96-e114. [PMID: 35139658 PMCID: PMC8957572 DOI: 10.1161/atvbaha.121.317324] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 01/24/2022] [Indexed: 01/23/2023]
Abstract
BACKGROUND Vascular pericytes stabilize blood vessels and contribute to their maturation, while playing other key roles in microvascular function. Nevertheless, relatively little is known about involvement of their precursors in the earliest stages of vascular development, specifically during vasculogenesis. METHODS We combined high-power, time-lapse imaging with transcriptional profiling of emerging pericytes and endothelial cells in reporter mouse and cell lines. We also analyzed conditional transgenic animals deficient in Cx43/Gja1 (connexin 43/gap junction alpha-1) expression within Ng2+ cells. RESULTS A subset of Ng2-DsRed+ cells, likely pericyte/mural cell precursors, arose alongside endothelial cell differentiation and organization and physically engaged vasculogenic endothelium in vivo and in vitro. We found no overlap between this population of differentiating pericyte/mural progenitors and other lineages including hemangiogenic and neuronal/glial cell types. We also observed cell-cell coupling and identified Cx43-based gap junctions contributing to pericyte-endothelial cell precursor communication during vascular assembly. Genetic loss of Cx43/Gja1 in Ng2+ pericyte progenitors compromised embryonic blood vessel formation in a subset of animals, while surviving mutants displayed little-to-no vessel abnormalities, suggesting a resilience to Cx43/Gja1 loss in Ng2+ cells or potential compensation by additional connexin isoforms. CONCLUSIONS Together, our data suggest that a distinct pericyte lineage emerges alongside vasculogenesis and directly communicates with the nascent endothelium via Cx43 during early vessel formation. Cx43/Gja1 loss in pericyte/mural cell progenitors can induce embryonic vessel dysmorphogenesis, but alternate connexin isoforms may be able to compensate. These data provide insight that may reshape the current framework of vascular development and may also inform tissue revascularization/vascularization strategies.
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Affiliation(s)
- Laura Beth Payne
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
| | - Bhanu P. Tewari
- Department of Neuroscience, University of Virginia, Charlottesville, VA 22903, USA
| | - Logan Dunkenberger
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
| | - Samantha Bond
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
| | - Alyssa Savelli
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| | - Jordan Darden
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
- Graduate Program in Translational Biology, Medicine and Health, Virginia Tech, Blacksburg, VA 24061, USA
| | - Huaning Zhao
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
| | - Caroline Willi
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
| | - Ronak Kanodia
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
| | - Rosalie Gude
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
| | - Michael D. Powell
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Kenneth J. Oestreich
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Harald Sontheimer
- Department of Neuroscience, University of Virginia, Charlottesville, VA 22903, USA
| | - Sophie Dal-Pra
- Division of Cardiovascular Medicine and Mandel Center for Hypertension Research and Division of Cardiovascular Medicine, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - John C. Chappell
- Center for Vascular and Heart Research, Fralin Biomedical Research Institute at Virginia Tech-Carilion, Roanoke, VA 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
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30
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Erdener ŞE, Küreli G, Dalkara T. Contractile apparatus in CNS capillary pericytes. NEUROPHOTONICS 2022; 9:021904. [PMID: 35106320 PMCID: PMC8785978 DOI: 10.1117/1.nph.9.2.021904] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Significance: Whether or not capillary pericytes contribute to blood flow regulation in the brain and retina has long been debated. This was partly caused by failure of detecting the contractile protein α -smooth muscle actin ( α -SMA) in capillary pericytes. Aim: The aim of this review is to summarize recent developments in detecting α -SMA and contractility in capillary pericytes and the relevant literature on the biology of actin filaments. Results: Evidence suggests that for visualization of the small amounts of α -SMA in downstream mid-capillary pericytes, actin depolymerization must be prevented during tissue processing. Actin filaments turnover is mainly based on de/re-polymerization rather than transcription of the monomeric form, hence, small amounts of α -SMA mRNA may evade detection by transcriptomic studies. Similarly, transgenic mice expressing fluorescent reporters under the α -SMA promoter may yield low fluorescence due to limited transcriptional activity in mid-capillary pericytes. Recent studies show that pericytes including mid-capillary ones express several actin isoforms and myosin heavy chain type 11, the partner of α -SMA in mediating contraction. Emerging evidence also suggests that actin polymerization in pericytes may have a role in regulating the tone of downstream capillaries. Conclusions: With guidance of actin biology, innovative labeling and imaging techniques can reveal the molecular machinery of contraction in pericytes.
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Affiliation(s)
- Şefik E. Erdener
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Gülce Küreli
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Turgay Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
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31
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Sancho M, Klug NR, Mughal A, Koide M, Huerta de la Cruz S, Heppner TJ, Bonev AD, Hill-Eubanks D, Nelson MT. Adenosine signaling activates ATP-sensitive K + channels in endothelial cells and pericytes in CNS capillaries. Sci Signal 2022; 15:eabl5405. [PMID: 35349300 DOI: 10.1126/scisignal.abl5405] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The dense network of capillaries composed of capillary endothelial cells (cECs) and pericytes lies in close proximity to all neurons, ideally positioning it to sense neuron- and glial-derived compounds that enhance regional and global cerebral perfusion. The membrane potential (VM) of vascular cells serves as the physiological bridge that translates brain activity into vascular function. In other beds, the ATP-sensitive K+ (KATP) channel regulates VM in vascular smooth muscle, which is absent in the capillary network. Here, with transgenic mice that expressed a dominant-negative mutant of the pore-forming Kir6.1 subunit specifically in brain cECs or pericytes, we demonstrated that KATP channels were present in both cell types and robustly controlled VM. We further showed that the signaling nucleotide adenosine acted through A2A receptors and the Gαs/cAMP/PKA pathway to activate capillary KATP channels. Moreover, KATP channel stimulation in vivo increased cerebral blood flow (CBF), an effect that was blunted by expression of the dominant-negative Kir6.1 mutant in either capillary cell type. These findings establish an important role for KATP channels in cECs and pericytes in the regulation of CBF.
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Affiliation(s)
- Maria Sancho
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA
| | - Nicholas R Klug
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA
| | - Amreen Mughal
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA
| | - Masayo Koide
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA.,Vermont Center for Cardiovascular and Brain Health, Larner College of Medicine, University of Vermont, Burlington, VT 05405-0068, USA
| | | | - Thomas J Heppner
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA
| | - Adrian D Bonev
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA
| | - David Hill-Eubanks
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT 05405-0068, USA.,Vermont Center for Cardiovascular and Brain Health, Larner College of Medicine, University of Vermont, Burlington, VT 05405-0068, USA.,Division of Cardiovascular Sciences, University of Manchester, Manchester M13 9PL, UK
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32
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Shaw K, Boyd K, Anderle S, Hammond-Haley M, Amin D, Bonnar O, Hall CN. Gradual Not Sudden Change: Multiple Sites of Functional Transition Across the Microvascular Bed. Front Aging Neurosci 2022; 13:779823. [PMID: 35237142 PMCID: PMC8885127 DOI: 10.3389/fnagi.2021.779823] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 12/20/2021] [Indexed: 01/03/2023] Open
Abstract
In understanding the role of the neurovascular unit as both a biomarker and target for disease interventions, it is vital to appreciate how the function of different components of this unit change along the vascular tree. The cells of the neurovascular unit together perform an array of vital functions, protecting the brain from circulating toxins and infection, while providing nutrients and clearing away waste products. To do so, the brain's microvasculature dilates to direct energy substrates to active neurons, regulates access to circulating immune cells, and promotes angiogenesis in response to decreased blood supply, as well as pulsating to help clear waste products and maintain the oxygen supply. Different parts of the cerebrovascular tree contribute differently to various aspects of these functions, and previously, it has been assumed that there are discrete types of vessel along the vascular network that mediate different functions. Another option, however, is that the multiple transitions in function that occur across the vascular network do so at many locations, such that vascular function changes gradually, rather than in sharp steps between clearly distinct vessel types. Here, by reference to new data as well as by reviewing historical and recent literature, we argue that this latter scenario is likely the case and that vascular function gradually changes across the network without clear transition points between arteriole, precapillary arteriole and capillary. This is because classically localized functions are in fact performed by wide swathes of the vasculature, and different functional markers start and stop being expressed at different points along the vascular tree. Furthermore, vascular branch points show alterations in their mural cell morphology that suggest functional specializations irrespective of their position within the network. Together this work emphasizes the need for studies to consider where transitions of different functions occur, and the importance of defining these locations, in order to better understand the vascular network and how to target it to treat disease.
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Affiliation(s)
- Kira Shaw
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
| | - Katie Boyd
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
| | - Silvia Anderle
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
| | | | - Davina Amin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Orla Bonnar
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown Navy Yard, MA, United States
| | - Catherine N. Hall
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
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Hartmann DA, Coelho-Santos V, Shih AY. Pericyte Control of Blood Flow Across Microvascular Zones in the Central Nervous System. Annu Rev Physiol 2022; 84:331-354. [PMID: 34672718 PMCID: PMC10480047 DOI: 10.1146/annurev-physiol-061121-040127] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The vast majority of the brain's vascular length is composed of capillaries, where our understanding of blood flow control remains incomplete. This review synthesizes current knowledge on the control of blood flow across microvascular zones by addressing issues with nomenclature and drawing on new developments from in vivo optical imaging and single-cell transcriptomics. Recent studies have highlighted important distinctions in mural cell morphology, gene expression, and contractile dynamics, which can explain observed differences in response to vasoactive mediators between arteriole, transitional, and capillary zones. Smooth muscle cells of arterioles and ensheathing pericytes of the arteriole-capillary transitional zone control large-scale, rapid changes in blood flow. In contrast, capillary pericytes downstream of the transitional zone act on slower and smaller scales and are involved in establishing resting capillary tone and flow heterogeneity. Many unresolved issues remain, including the vasoactive mediators that activate the different pericyte types in vivo, the role of pericyte-endothelial communication in conducting signals from capillaries to arterioles, and how neurological disease affects these mechanisms.
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Affiliation(s)
- David A Hartmann
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA;
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA;
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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34
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Baumann J, Tsao CC, Patkar S, Huang SF, Francia S, Magnussen SN, Gassmann M, Vogel J, Köster-Hegmann C, Ogunshola OO. Pericyte, but not astrocyte, hypoxia inducible factor-1 (HIF-1) drives hypoxia-induced vascular permeability in vivo. Fluids Barriers CNS 2022; 19:6. [PMID: 35033138 PMCID: PMC8760662 DOI: 10.1186/s12987-021-00302-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Ways to prevent disease-induced vascular modifications that accelerate brain damage remain largely elusive. Improved understanding of perivascular cell signalling could provide unparalleled insight as these cells impact vascular stability and functionality of the neurovascular unit as a whole. Identifying key drivers of astrocyte and pericyte responses that modify cell-cell interactions and crosstalk during injury is key. At the cellular level, injury-induced outcomes are closely entwined with activation of the hypoxia-inducible factor-1 (HIF-1) pathway. Studies clearly suggest that endothelial HIF-1 signalling increases blood-brain barrier permeability but the influence of perivascular HIF-1 induction on outcome is unknown. Using novel mouse lines with astrocyte and pericyte targeted HIF-1 loss of function, we herein show that vascular stability in vivo is differentially impacted by perivascular hypoxia-induced HIF-1 stabilization. METHODS To facilitate HIF-1 deletion in adult mice without developmental complications, novel Cre-inducible astrocyte-targeted (GFAP-CreERT2; HIF-1αfl/fl and GLAST-CreERT2; HIF-1αfl/fl) and pericyte-targeted (SMMHC-CreERT2; HIF-1αfl/fl) transgenic animals were generated. Mice in their home cages were exposed to either normoxia (21% O2) or hypoxia (8% O2) for 96 h in an oxygen-controlled humidified glove box. All lines were similarly responsive to hypoxic challenge and post-Cre activation showed significantly reduced HIF-1 target gene levels in the individual cells as predicted. RESULTS Unexpectedly, hypoxia-induced vascular remodelling was unaffected by HIF-1 loss of function in the two astrocyte lines but effectively blocked in the pericyte line. In correlation, hypoxia-induced barrier permeability and water accumulation were abrogated only in pericyte targeted HIF-1 loss of function mice. In contrast to expectation, brain and serum levels of hypoxia-induced VEGF, TGF-β and MMPs (genes known to mediate vascular remodelling) were unaffected by HIF-1 deletion in all lines. However, in agreement with the permeability data, immunofluorescence and electron microscopy showed clear prevention of hypoxia-induced tight junction disruption in the pericyte loss of function line. CONCLUSION This study shows that pericyte but not astrocyte HIF-1 stabilization modulates endothelial tight junction functionality and thereby plays a pivotal role in hypoxia-induced vascular dysfunction. Whether the cells respond similarly or differentially to other injury stimuli will be of significant relevance.
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Affiliation(s)
- Julia Baumann
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Chih-Chieh Tsao
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Shalmali Patkar
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Sheng-Fu Huang
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Simona Francia
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Synnøve Norvoll Magnussen
- Institute of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Max Gassmann
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Johannes Vogel
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Christina Köster-Hegmann
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland
| | - Omolara O Ogunshola
- Institute of Veterinary Physiology and Center for Clinical Studies, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland.
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35
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Ivanova E, Corona C, Eleftheriou CG, Stout RF, Körbelin J, Sagdullaev BT. AAV-BR1 targets endothelial cells in the retina to reveal their morphological diversity and to deliver Cx43. J Comp Neurol 2021; 530:1302-1317. [PMID: 34811744 DOI: 10.1002/cne.25277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 11/13/2021] [Accepted: 11/16/2021] [Indexed: 12/15/2022]
Abstract
Endothelial cells (ECs) are key players in the development and maintenance of the vascular tree, the establishment of the blood-brain barrier and control of blood flow. Disruption in ECs is an early and active component of vascular pathogenesis. However, our ability to selectively target ECs in the CNS for identification and manipulation is limited. Here, in the mouse retina, a tractable model of the CNS, we utilized a recently developed AAV-BR1 system to identify distinct classes of ECs along the vascular tree using a GFP reporter. We then developed an inducible EC-specific ectopic Connexin 43 (Cx43) expression system using AAV-BR1-CAG-DIO-Cx43-P2A-DsRed2 in combination with a mouse line carrying inducible CreERT2 in ECs. We targeted Cx43 because its loss has been implicated in microvascular impairment in numerous diseases such as diabetic retinopathy and vascular edema. GFP-labeled ECs were numerous, evenly distributed along the vascular tree and their morphology was polarized with respect to the direction of blood flow. After tamoxifen induction, ectopic Cx43 was specifically expressed in ECs. Similarly to endogenous Cx43, ectopic Cx43 was localized at the membrane contacts of ECs and it did not affect tight junction proteins. The ability to enhance gap junctions in ECs provides a precise and potentially powerful tool to treat microcirculation deficits, an early pathology in numerous diseases.
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Affiliation(s)
- Elena Ivanova
- Burke Neurological Institute, White Plains, New York, USA.,Brain and Mind Research Institute, Weill Cornell Medicine, White Plains, New York, USA
| | - Carlo Corona
- Burke Neurological Institute, White Plains, New York, USA
| | | | - Randy F Stout
- Department of Biomedical Sciences, The New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Jakob Körbelin
- Department of Oncology, Hematology, and Bone Marrow Transplantation, University Medical Center Hamburg-Eppendorf, Hamburg, USA
| | - Botir T Sagdullaev
- Burke Neurological Institute, White Plains, New York, USA.,Brain and Mind Research Institute, Weill Cornell Medicine, White Plains, New York, USA.,Department of Ophthalmology, Weill Cornell Medicine, White Plains, New York, USA
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36
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Lourenço CF, Laranjinha J. Nitric Oxide Pathways in Neurovascular Coupling Under Normal and Stress Conditions in the Brain: Strategies to Rescue Aberrant Coupling and Improve Cerebral Blood Flow. Front Physiol 2021; 12:729201. [PMID: 34744769 PMCID: PMC8569710 DOI: 10.3389/fphys.2021.729201] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/20/2021] [Indexed: 01/04/2023] Open
Abstract
The brain has impressive energy requirements and paradoxically, very limited energy reserves, implying its huge dependency on continuous blood supply. Aditionally, cerebral blood flow must be dynamically regulated to the areas of increased neuronal activity and thus, of increased metabolic demands. The coupling between neuronal activity and cerebral blood flow (CBF) is supported by a mechanism called neurovascular coupling (NVC). Among the several vasoactive molecules released by glutamatergic activation, nitric oxide (•NO) is recognized to be a key player in the process and essential for the development of the neurovascular response. Classically, •NO is produced in neurons upon the activation of the glutamatergic N-methyl-D-aspartate (NMDA) receptor by the neuronal isoform of nitric oxide synthase and promotes vasodilation by activating soluble guanylate cyclase in the smooth muscle cells of the adjacent arterioles. This pathway is part of a more complex network in which other molecular and cellular intervenients, as well as other sources of •NO, are involved. The elucidation of these interacting mechanisms is fundamental in understanding how the brain manages its energy requirements and how the failure of this process translates into neuronal dysfunction. Here, we aimed to provide an integrated and updated perspective of the role of •NO in the NVC, incorporating the most recent evidence that reinforces its central role in the process from both viewpoints, as a physiological mediator and a pathological stressor. First, we described the glutamate-NMDA receptor-nNOS axis as a central pathway in NVC, then we reviewed the link between the derailment of the NVC and neuronal dysfunction associated with neurodegeneration (with a focus on Alzheimer's disease). We further discussed the role of oxidative stress in the NVC dysfunction, specifically by decreasing the •NO bioavailability and diverting its bioactivity toward cytotoxicity. Finally, we highlighted some strategies targeting the rescue or maintenance of •NO bioavailability that could be explored to mitigate the NVC dysfunction associated with neurodegenerative conditions. In line with this, the potential modulatory effects of dietary nitrate and polyphenols on •NO-dependent NVC, in association with physical exercise, may be used as effective non-pharmacological strategies to promote the •NO bioavailability and to manage NVC dysfunction in neuropathological conditions.
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Affiliation(s)
- Cátia F Lourenço
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - João Laranjinha
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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37
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Szarka G, Balogh M, Tengölics ÁJ, Ganczer A, Völgyi B, Kovács-Öller T. The role of gap junctions in cell death and neuromodulation in the retina. Neural Regen Res 2021; 16:1911-1920. [PMID: 33642359 PMCID: PMC8343308 DOI: 10.4103/1673-5374.308069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/14/2020] [Accepted: 01/11/2021] [Indexed: 12/26/2022] Open
Abstract
Vision altering diseases, such as glaucoma, diabetic retinopathy, age-related macular degeneration, myopia, retinal vascular disease, traumatic brain injuries and others cripple many lives and are projected to continue to cause anguish in the foreseeable future. Gap junctions serve as an emerging target for neuromodulation and possible regeneration as they directly connect healthy and/or diseased cells, thereby playing a crucial role in pathophysiology. Since they are permeable for macromolecules, able to cross the cellular barriers, they show duality in illness as a cause and as a therapeutic target. In this review, we take recent advancements in gap junction neuromodulation (pharmacological blockade, gene therapy, electrical and light stimulation) into account, to show the gap junction's role in neuronal cell death and the possible routes of rescuing neuronal and glial cells in the retina succeeding illness or injury.
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Affiliation(s)
- Gergely Szarka
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Márton Balogh
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Ádám J. Tengölics
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Alma Ganczer
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Béla Völgyi
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- Medical School, University of Pécs, Pécs, Hungary
| | - Tamás Kovács-Öller
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Medical School, University of Pécs, Pécs, Hungary
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38
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Ornelas S, Berthiaume AA, Bonney SK, Coelho-Santos V, Underly RG, Kremer A, Guérin CJ, Lippens S, Shih AY. Three-dimensional ultrastructure of the brain pericyte-endothelial interface. J Cereb Blood Flow Metab 2021; 41:2185-2200. [PMID: 33970018 PMCID: PMC8393306 DOI: 10.1177/0271678x211012836] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pericytes and endothelial cells share membranous interdigitations called "peg-and-socket" interactions that facilitate their adhesion and biochemical crosstalk during vascular homeostasis. However, the morphology and distribution of these ultrastructures have remained elusive. Using a combination of 3D electron microscopy techniques, we examined peg-and-socket interactions in mouse brain capillaries. We found that pegs extending from pericytes to endothelial cells were morphologically diverse, exhibiting claw-like morphologies at the edge of the cell and bouton-shaped swellings away from the edge. Reciprocal endothelial pegs projecting into pericytes were less abundant and appeared as larger columnar protuberances. A large-scale 3D EM data set revealed enrichment of both pericyte and endothelial pegs around pericyte somata. The ratio of pericyte versus endothelial pegs was conserved among the pericytes examined, but total peg abundance was heterogeneous across cells. These data show considerable investment between pericytes and endothelial cells, and provide morphological evidence for pericyte somata as sites of enriched physical and biochemical interaction.
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Affiliation(s)
- Sharon Ornelas
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Stephanie K Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Robert G Underly
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Anna Kremer
- VIB BioImaging Core, VIB, Ghent, Belgium
- VIB Inflammation Research Center, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Christopher J Guérin
- VIB BioImaging Core, VIB, Ghent, Belgium
- VIB Inflammation Research Center, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Saskia Lippens
- VIB BioImaging Core, VIB, Ghent, Belgium
- VIB Inflammation Research Center, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Andy Y Shih, Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, 1900 9th Avenue M/S JMB.-5, Seattle, WA 98101, USA.
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39
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Eltanahy AM, Koluib YA, Gonzales A. Pericytes: Intrinsic Transportation Engineers of the CNS Microcirculation. Front Physiol 2021; 12:719701. [PMID: 34497540 PMCID: PMC8421025 DOI: 10.3389/fphys.2021.719701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/29/2021] [Indexed: 12/15/2022] Open
Abstract
Pericytes in the brain are candidate regulators of microcirculatory blood flow because they are strategically positioned along the microvasculature, contain contractile proteins, respond rapidly to neuronal activation, and synchronize microvascular dynamics and neurovascular coupling within the capillary network. Analyses of mice with defects in pericyte generation demonstrate that pericytes are necessary for the formation of the blood-brain barrier, development of the glymphatic system, immune homeostasis, and white matter function. The development, identity, specialization, and progeny of different subtypes of pericytes, however, remain unclear. Pericytes perform brain-wide 'transportation engineering' functions in the capillary network, instructing, integrating, and coordinating signals within the cellular communicome in the neurovascular unit to efficiently distribute oxygen and nutrients ('goods and services') throughout the microvasculature ('transportation grid'). In this review, we identify emerging challenges in pericyte biology and shed light on potential pericyte-targeted therapeutic strategies.
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Affiliation(s)
- Ahmed M. Eltanahy
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Yara A. Koluib
- Tanta University Hospitals, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Albert Gonzales
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
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40
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Stackhouse TL, Mishra A. Neurovascular Coupling in Development and Disease: Focus on Astrocytes. Front Cell Dev Biol 2021; 9:702832. [PMID: 34327206 PMCID: PMC8313501 DOI: 10.3389/fcell.2021.702832] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/09/2021] [Indexed: 12/14/2022] Open
Abstract
Neurovascular coupling is a crucial mechanism that matches the high energy demand of the brain with a supply of energy substrates from the blood. Signaling within the neurovascular unit is responsible for activity-dependent changes in cerebral blood flow. The strength and reliability of neurovascular coupling form the basis of non-invasive human neuroimaging techniques, including blood oxygen level dependent (BOLD) functional magnetic resonance imaging. Interestingly, BOLD signals are negative in infants, indicating a mismatch between metabolism and blood flow upon neural activation; this response is the opposite of that observed in healthy adults where activity evokes a large oversupply of blood flow. Negative neurovascular coupling has also been observed in rodents at early postnatal stages, further implying that this is a process that matures during development. This rationale is consistent with the morphological maturation of the neurovascular unit, which occurs over a similar time frame. While neurons differentiate before birth, astrocytes differentiate postnatally in rodents and the maturation of their complex morphology during the first few weeks of life links them with synapses and the vasculature. The vascular network is also incomplete in neonates and matures in parallel with astrocytes. Here, we review the timeline of the structural maturation of the neurovascular unit with special emphasis on astrocytes and the vascular tree and what it implies for functional maturation of neurovascular coupling. We also discuss similarities between immature astrocytes during development and reactive astrocytes in disease, which are relevant to neurovascular coupling. Finally, we close by pointing out current gaps in knowledge that must be addressed to fully elucidate the mechanisms underlying neurovascular coupling maturation, with the expectation that this may also clarify astrocyte-dependent mechanisms of cerebrovascular impairment in neurodegenerative conditions in which reduced or negative neurovascular coupling is noted, such as stroke and Alzheimer’s disease.
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Affiliation(s)
- Teresa L Stackhouse
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States
| | - Anusha Mishra
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States.,Knight Cardiovascular Institute, Oregon Health & Sciences University, Portland, OR, United States
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41
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Glück C, Ferrari KD, Binini N, Keller A, Saab AS, Stobart JL, Weber B. Distinct signatures of calcium activity in brain mural cells. eLife 2021; 10:e70591. [PMID: 34227466 PMCID: PMC8294852 DOI: 10.7554/elife.70591] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 06/15/2021] [Indexed: 12/15/2022] Open
Abstract
Pericytes have been implicated in various neuropathologies, yet little is known about their function and signaling pathways in health. Here, we characterized calcium dynamics of cortical mural cells in anesthetized or awake Pdgfrb-CreERT2;Rosa26< LSL-GCaMP6s > mice and in acute brain slices. Smooth muscle cells (SMCs) and ensheathing pericytes (EPs), also named as terminal vascular SMCs, revealed similar calcium dynamics in vivo. In contrast, calcium signals in capillary pericytes (CPs) were irregular, higher in frequency, and occurred in cellular microdomains. In the absence of the vessel constricting agent U46619 in acute slices, SMCs and EPs revealed only sparse calcium signals, whereas CPs retained their spontaneous calcium activity. Interestingly, chemogenetic activation of neurons in vivo and acute elevations of extracellular potassium in brain slices strongly decreased calcium activity in CPs. We propose that neuronal activation and an extracellular increase in potassium suppress calcium activity in CPs, likely mediated by Kir2.2 and KATP channels.
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Affiliation(s)
- Chaim Glück
- Institute of Pharmacology and Toxicology, University of ZurichZürichSwitzerland
- Neuroscience Center Zurich, University and ETH ZurichZurichSwitzerland
| | - Kim David Ferrari
- Institute of Pharmacology and Toxicology, University of ZurichZürichSwitzerland
- Neuroscience Center Zurich, University and ETH ZurichZurichSwitzerland
| | - Noemi Binini
- Institute of Pharmacology and Toxicology, University of ZurichZürichSwitzerland
- Neuroscience Center Zurich, University and ETH ZurichZurichSwitzerland
| | - Annika Keller
- Neuroscience Center Zurich, University and ETH ZurichZurichSwitzerland
- Department of Neurosurgery, University of ZurichSchlierenSwitzerland
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology, University of ZurichZürichSwitzerland
- Neuroscience Center Zurich, University and ETH ZurichZurichSwitzerland
| | - Jillian L Stobart
- Institute of Pharmacology and Toxicology, University of ZurichZürichSwitzerland
- Rady Faculty of Health Sciences, College of PharmacyWinnipegCanada
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of ZurichZürichSwitzerland
- Neuroscience Center Zurich, University and ETH ZurichZurichSwitzerland
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42
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Sharma S, Brown CE. Microvascular basis of cognitive impairment in type 1 diabetes. Pharmacol Ther 2021; 229:107929. [PMID: 34171341 DOI: 10.1016/j.pharmthera.2021.107929] [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] [Received: 02/24/2021] [Revised: 04/23/2021] [Accepted: 05/19/2021] [Indexed: 02/07/2023]
Abstract
The complex computations of the brain require a constant supply of blood flow to meet its immense metabolic needs. Perturbations in blood supply, even in the smallest vascular networks, can have a profound effect on neuronal function and cognition. Type 1 diabetes is a prevalent and insidious metabolic disorder that progressively and heterogeneously disrupts vascular signalling and function in the brain. As a result, it is associated with an array of adverse vascular changes such as impaired regulation of vascular tone, pathological neovascularization and vasoregression, capillary plugging and blood brain barrier disruption. In this review, we highlight the link between microvascular dysfunction and cognitive impairment that is commonly associated with type 1 diabetes, with the aim of synthesizing current knowledge in this field.
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Affiliation(s)
- Sorabh Sharma
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Craig E Brown
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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43
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Gameiro GR, Gameiro GR, Farah ME, Wang J, Schor P. Retinal microvascular density modifications during the water drinking test. Eur J Ophthalmol 2021; 32:1602-1609. [PMID: 34137302 DOI: 10.1177/11206721211024058] [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] [Indexed: 11/16/2022]
Abstract
PURPOSE The water drinking test (WDT) is a well-known stress test that increases intraocular pressure (IOP) momentarily and can indicate risk of glaucoma progression. This study focuses on correlating changes in the retinal microvascular plexus with the WDT in young healthy subjects. METHODS A total of 20 eyes of 20 healthy young subjects (mean age 24.37 ± 2.17 years) were included in this study. In our protocol, WDT consisted of drinking 1 L of water within 5 min. Outcome measures in this prospective observational study were mean arterial pressure (MAP), heart rate (HR), IOP, and retinal vessel density of both superficial and deep macular retina using optical coherence tomography angiography (OCTA), which were assessed before water ingestion and four times after at 15-min intervals. OCTA images were later quantified by fractal analysis (box counting [Dbox]). One-way repeated measures analysis of variance (ANOVA) was used to assess the effects of WDT on each of the parameters. RESULTS The WDT resulted in significant peak changes of the following parameters compared to baseline: IOP: 15.63 ± 3.37 versus 18.38 ± 4.53 mmHg at 30 min, p < 0.001; HR: 75.74 ± 12.23 versus 64.95 ± 11.37 bpm at 15 min, p < 0.001; deep retinal vessel density 1.758 ± 0.14 versus 1.749 ± 0.16 at 15 min, p = 0.040. CONCLUSIONS Besides IOP elevation and systemic effects in HR, WDT is associated with temporary modifications of the deep vascular plexus in young healthy subjects.
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Affiliation(s)
- Gustavo Rosa Gameiro
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo - EPM/UNIFESP, São Paulo, São Paulo, Brazil
| | - Giovana Rosa Gameiro
- Health Sciences Center, State University of Londrina, Londrina, Parana, Brazil.,Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Michel Eid Farah
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo - EPM/UNIFESP, São Paulo, São Paulo, Brazil
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Paulo Schor
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo - EPM/UNIFESP, São Paulo, São Paulo, Brazil
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44
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Negri S, Faris P, Soda T, Moccia F. Endothelial signaling at the core of neurovascular coupling: The emerging role of endothelial inward-rectifier K + (K ir2.1) channels and N-methyl-d-aspartate receptors in the regulation of cerebral blood flow. Int J Biochem Cell Biol 2021; 135:105983. [PMID: 33894355 DOI: 10.1016/j.biocel.2021.105983] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/08/2021] [Accepted: 04/19/2021] [Indexed: 12/21/2022]
Abstract
Neurovascular coupling (NVC) represents the mechanisms whereby an increase in neuronal activity (NA) may lead to local vasodilation and increase in regional cerebral blood flow (CBF). It has long been thought that neurons and astrocytes generate the vasoactive mediators regulating local changes in CBF, whereas cerebrovascular endothelial cells are not able to directly sense NA. Unexpectedly, recent evidence demonstrated that brain microvascular endothelial cells may sense NA through inward-rectifier K+ (Kir2.1) channels and may detect synaptic activity via N-methyl-d-aspartate (NMDA) receptors (NMDARs). In the present perspective, therefore, we discuss the hypothesis that endothelial Kir2.1 channels and NMDARs play a key role in NVC and in CBF regulation, which is crucial to unravel the cellular and molecular underpinnings of blood oxygen level-dependent signals.
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Affiliation(s)
- Sharon Negri
- Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratory of General Physiology, University of Pavia, Pavia, Italy
| | - Pawan Faris
- Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratory of General Physiology, University of Pavia, Pavia, Italy
| | - Teresa Soda
- Department of Brain and Behavioral Sciences, University if Pavia, Pavia, Italy
| | - Francesco Moccia
- Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratory of General Physiology, University of Pavia, Pavia, Italy.
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45
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Cameron T, Bennet T, Rowe EM, Anwer M, Wellington CL, Cheung KC. Review of Design Considerations for Brain-on-a-Chip Models. MICROMACHINES 2021; 12:441. [PMID: 33921018 PMCID: PMC8071412 DOI: 10.3390/mi12040441] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
In recent years, the need for sophisticated human in vitro models for integrative biology has motivated the development of organ-on-a-chip platforms. Organ-on-a-chip devices are engineered to mimic the mechanical, biochemical and physiological properties of human organs; however, there are many important considerations when selecting or designing an appropriate device for investigating a specific scientific question. Building microfluidic Brain-on-a-Chip (BoC) models from the ground-up will allow for research questions to be answered more thoroughly in the brain research field, but the design of these devices requires several choices to be made throughout the design development phase. These considerations include the cell types, extracellular matrix (ECM) material(s), and perfusion/flow considerations. Choices made early in the design cycle will dictate the limitations of the device and influence the end-point results such as the permeability of the endothelial cell monolayer, and the expression of cell type-specific markers. To better understand why the engineering aspects of a microfluidic BoC need to be influenced by the desired biological environment, recent progress in microfluidic BoC technology is compared. This review focuses on perfusable blood-brain barrier (BBB) and neurovascular unit (NVU) models with discussions about the chip architecture, the ECM used, and how they relate to the in vivo human brain. With increased knowledge on how to make informed choices when selecting or designing BoC models, the scientific community will benefit from shorter development phases and platforms curated for their application.
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Affiliation(s)
- Tiffany Cameron
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (T.C.); (T.B.)
- Centre for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Tanya Bennet
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (T.C.); (T.B.)
- Centre for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Elyn M. Rowe
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (E.M.R.); (M.A.); (C.L.W.)
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Mehwish Anwer
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (E.M.R.); (M.A.); (C.L.W.)
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Cheryl L. Wellington
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (E.M.R.); (M.A.); (C.L.W.)
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Karen C. Cheung
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (T.C.); (T.B.)
- Centre for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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Dessalles CA, Babataheri A, Barakat AI. Pericyte mechanics and mechanobiology. J Cell Sci 2021; 134:134/6/jcs240226. [PMID: 33753399 DOI: 10.1242/jcs.240226] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pericytes are mural cells of the microvasculature, recognized by their thin processes and protruding cell body. Pericytes wrap around endothelial cells and play a central role in regulating various endothelial functions, including angiogenesis and inflammation. They also serve as a vascular support and regulate blood flow by contraction. Prior reviews have examined pericyte biological functions and biochemical signaling pathways. In this Review, we focus on the role of mechanics and mechanobiology in regulating pericyte function. After an overview of the morphology and structure of pericytes, we describe their interactions with both the basement membrane and endothelial cells. We then turn our attention to biophysical considerations, and describe contractile forces generated by pericytes, mechanical forces exerted on pericytes, and pericyte responses to these forces. Finally, we discuss 2D and 3D engineered in vitro models for studying pericyte mechano-responsiveness and underscore the need for more evolved models that provide improved understanding of pericyte function and dysfunction.
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Affiliation(s)
- Claire A Dessalles
- LadHyX, CNRS, Ecole polytechnique, Institut polytechnique de Paris, 91120, Palaiseau, France
| | - Avin Babataheri
- LadHyX, CNRS, Ecole polytechnique, Institut polytechnique de Paris, 91120, Palaiseau, France
| | - Abdul I Barakat
- LadHyX, CNRS, Ecole polytechnique, Institut polytechnique de Paris, 91120, Palaiseau, France
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47
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González-Casanova J, Schmachtenberg O, Martínez AD, Sanchez HA, Harcha PA, Rojas-Gomez D. An Update on Connexin Gap Junction and Hemichannels in Diabetic Retinopathy. Int J Mol Sci 2021; 22:ijms22063194. [PMID: 33801118 PMCID: PMC8004116 DOI: 10.3390/ijms22063194] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/06/2021] [Accepted: 03/10/2021] [Indexed: 01/10/2023] Open
Abstract
Diabetic retinopathy (DR) is one of the main causes of vision loss in the working age population. It is characterized by a progressive deterioration of the retinal microvasculature, caused by long-term metabolic alterations inherent to diabetes, leading to a progressive loss of retinal integrity and function. The mammalian retina presents an orderly layered structure that executes initial but complex visual processing and analysis. Gap junction channels (GJC) forming electrical synapses are present in each retinal layer and contribute to the communication between different cell types. In addition, connexin hemichannels (HCs) have emerged as relevant players that influence diverse physiological and pathological processes in the retina. This article highlights the impact of diabetic conditions on GJC and HCs physiology and their involvement in DR pathogenesis. Microvascular damage and concomitant loss of endothelial cells and pericytes are related to alterations in gap junction intercellular communication (GJIC) and decreased connexin 43 (Cx43) expression. On the other hand, it has been shown that the expression and activity of HCs are upregulated in DR, becoming a key element in the establishment of proinflammatory conditions that emerge during hyperglycemia. Hence, novel connexin HCs blockers or drugs to enhance GJIC are promising tools for the development of pharmacological interventions for diabetic retinopathy, and initial in vitro and in vivo studies have shown favorable results in this regard.
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Affiliation(s)
- Jorge González-Casanova
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago 8910060, Chile;
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile;
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (A.D.M.); (H.A.S.); (P.A.H.)
| | - Helmuth A. Sanchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (A.D.M.); (H.A.S.); (P.A.H.)
| | - Paloma A. Harcha
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (A.D.M.); (H.A.S.); (P.A.H.)
| | - Diana Rojas-Gomez
- Escuela de Nutrición y Dietética, Facultad de Medicina, Universidad Andres Bello, Santiago 8370146, Chile
- Correspondence: ; Tel.: +56-2-26618559
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McDowell KP, Berthiaume AA, Tieu T, Hartmann DA, Shih AY. VasoMetrics: unbiased spatiotemporal analysis of microvascular diameter in multi-photon imaging applications. Quant Imaging Med Surg 2021; 11:969-982. [PMID: 33654670 PMCID: PMC7829163 DOI: 10.21037/qims-20-920] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/17/2020] [Indexed: 01/13/2023]
Abstract
BACKGROUND Multi-photon imaging of the cerebrovasculature provides rich data on the dynamics of cortical arterioles, capillaries, and venules. Vascular diameter is the major determinant of blood flow resistance, and is the most commonly quantified metric in studies of the cerebrovasculature. However, there is a lack of accessible and easy-to-use methods to quantify vascular diameter in imaging data. METHODS We created VasoMetrics, a macro written in ImageJ/Fiji for spatiotemporal analysis of microvascular diameter. The key feature of VasoMetrics is rapid analysis of many evenly spaced cross-sectional lines along the vessel of interest, permitting the extraction of numerous diameter measurements from individual vessels. Here we demonstrated the utility of VasoMetrics by analyzing in vivo multi-photon imaging stacks and movies collected from lightly sedated mice, as well as data from optical coherence tomography angiography (OCTA) of human retina. RESULTS Compared to the standard approach, which is to measure cross-sectional diameters at arbitrary points along a vessel, VasoMetrics accurately reported spatiotemporal features of vessel diameter, reduced measurement bias and time spent analyzing data, and improved the reproducibility of diameter measurements between users. VasoMetrics revealed the dynamics in pial arteriole diameters during vasomotion at rest, as well as changes in capillary diameter before and after pericyte ablation. Retinal arteriole diameter was quantified from a human retinal angiogram, providing proof-of-principle that VasoMetrics can be applied to contrast-enhanced clinical imaging of microvasculature. CONCLUSIONS VasoMetrics is a robust macro for spatiotemporal analysis of microvascular diameter in imaging applications.
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Affiliation(s)
- Konnor P. McDowell
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Taryn Tieu
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - David A. Hartmann
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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49
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Fosse JH, Haraldsen G, Falk K, Edelmann R. Endothelial Cells in Emerging Viral Infections. Front Cardiovasc Med 2021; 8:619690. [PMID: 33718448 PMCID: PMC7943456 DOI: 10.3389/fcvm.2021.619690] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
There are several reasons to consider the role of endothelial cells in COVID-19 and other emerging viral infections. First, severe cases of COVID-19 show a common breakdown of central vascular functions. Second, SARS-CoV-2 replicates in endothelial cells. Third, prior deterioration of vascular function exacerbates disease, as the most common comorbidities of COVID-19 (obesity, hypertension, and diabetes) are all associated with endothelial dysfunction. Importantly, SARS-CoV-2's ability to infect endothelium is shared by many emerging viruses, including henipaviruses, hantavirus, and highly pathogenic avian influenza virus, all specifically targeting endothelial cells. The ability to infect endothelium appears to support generalised dissemination of infection and facilitate the access to certain tissues. The disturbed vascular function observed in severe COVID-19 is also a prominent feature of many other life-threatening viral diseases, underscoring the need to understand how viruses modulate endothelial function. We here review the role of vascular endothelial cells in emerging viral infections, starting with a summary of endothelial cells as key mediators and regulators of vascular and immune responses in health and infection. Next, we discuss endotheliotropism as a possible virulence factor and detail features that regulate viruses' ability to attach to and enter endothelial cells. We move on to review how endothelial cells detect invading viruses and respond to infection, with particular focus on pathways that may influence vascular function and the host immune system. Finally, we discuss how endothelial cell function can be dysregulated in viral disease, either by viral components or as bystander victims of overshooting or detrimental inflammatory and immune responses. Many aspects of how viruses interact with the endothelium remain poorly understood. Considering the diversity of such mechanisms among different emerging viruses allows us to highlight common features that may be of general validity and point out important challenges.
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Affiliation(s)
| | - Guttorm Haraldsen
- Department of Pathology, Oslo University Hospital, Oslo, Norway.,Department of Pathology, University of Oslo, Oslo, Norway
| | - Knut Falk
- Norwegian Veterinary Institute, Oslo, Norway.,AquaMed Consulting AS, Oslo, Norway
| | - Reidunn Edelmann
- Department of Clinical Medicine, Centre for Cancer Biomarkers CCBIO, University of Bergen, Bergen, Norway
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50
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Pfeiffer T, Li Y, Attwell D. Diverse mechanisms regulating brain energy supply at the capillary level. Curr Opin Neurobiol 2021; 69:41-50. [PMID: 33485189 DOI: 10.1016/j.conb.2020.12.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/28/2020] [Accepted: 12/13/2020] [Indexed: 02/06/2023]
Abstract
Neural information processing depends critically on the brain's energy supply, which is provided in the form of glucose and oxygen in the blood. Regulation of this supply occurs by smooth muscle and contractile pericytes adjusting the diameter of arterioles and capillaries, respectively. Controversies exist over the relative importance of capillary and arteriolar level control, whether enzymatically generated signals or K+ ions are the dominant controller of cerebral blood flow, and the involvement of capillary endothelial cells. Here, we try to synthesise the relevant recent data into a coherent view of how brain energy supply is controlled and suggest approaches to answering key questions.
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Affiliation(s)
- Thomas Pfeiffer
- Department of Neuroscience, Physiology & Pharmacology, University College London Gower Street, London, WC1E 6BT, UK.
| | - Yuening Li
- Department of Neuroscience, Physiology & Pharmacology, University College London Gower Street, London, WC1E 6BT, UK
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London Gower Street, London, WC1E 6BT, UK.
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