1
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Cao Y, Xu W, Liu Q. Alterations of the blood-brain barrier during aging. J Cereb Blood Flow Metab 2024; 44:881-895. [PMID: 38513138 DOI: 10.1177/0271678x241240843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
The blood-brain barrier (BBB) is a complex and dynamic interface that regulates the exchange of molecules and cells between the blood and the central nervous system. It undergoes structural and functional changes during aging, which may compromise its integrity and contribute to the pathogenesis of neurodegenerative diseases. In recent years, advances in microscopy and high-throughput bioinformatics have allowed a more in-depth investigation of the aging mechanisms of BBB. This review summarizes age-related alterations of the BBB structure and function from six perspectives: endothelial cells, astrocytes, pericytes, basement membrane, microglia and perivascular macrophages, and fibroblasts, ranging from the molecular level to the human multi-system level. These basic components are essential for the proper functioning of the BBB. Recent imaging methods of BBB were also reviewed. Elucidation of age-associated BBB changes may offer insights into BBB homeostasis and may provide effective therapeutic strategies to protect it during aging.
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Affiliation(s)
- Yufan Cao
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Weihai Xu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qing Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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2
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Stankovic I, Notaras M, Wolujewicz P, Lu T, Lis R, Ross ME, Colak D. Schizophrenia endothelial cells exhibit higher permeability and altered angiogenesis patterns in patient-derived organoids. Transl Psychiatry 2024; 14:53. [PMID: 38263175 PMCID: PMC10806043 DOI: 10.1038/s41398-024-02740-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 12/29/2023] [Accepted: 01/05/2024] [Indexed: 01/25/2024] Open
Abstract
Schizophrenia (SCZ) is a complex neurodevelopmental disorder characterized by the manifestation of psychiatric symptoms in early adulthood. While many research avenues into the origins of SCZ during brain development have been explored, the contribution of endothelial/vascular dysfunction to the disease remains largely elusive. To model the neuropathology of SCZ during early critical periods of brain development, we utilized patient-derived induced pluripotent stem cells (iPSCs) to generate 3D cerebral organoids and define cell-specific signatures of disease. Single-cell RNA sequencing revealed that while SCZ organoids were similar in their macromolecular diversity to organoids generated from healthy controls (CTRL), SCZ organoids exhibited a higher percentage of endothelial cells when normalized to total cell numbers. Additionally, when compared to CTRL, differential gene expression analysis revealed a significant enrichment in genes that function in vessel formation, vascular regulation, and inflammatory response in SCZ endothelial cells. In line with these findings, data from 23 donors demonstrated that PECAM1+ microvascular vessel-like structures were increased in length and number in SCZ organoids in comparison to CTRL organoids. Furthermore, we report that patient-derived endothelial cells displayed higher paracellular permeability, implicating elevated vascular activity. Collectively, our data identified altered gene expression patterns, vessel-like structural changes, and enhanced permeability of endothelial cells in patient-derived models of SCZ. Hence, brain microvascular cells could play a role in the etiology of SCZ by modulating the permeability of the developing blood brain barrier (BBB).
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Affiliation(s)
- Isidora Stankovic
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Michael Notaras
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Paul Wolujewicz
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Tyler Lu
- Ansary Stem Cell Institute, Division of Regenerative Medicine, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Raphael Lis
- Ansary Stem Cell Institute, Division of Regenerative Medicine, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY, USA
| | - M Elizabeth Ross
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Dilek Colak
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA.
- Gale and Ira Drukier Institute for Children's Health, Weill Cornell Medicine, Cornell University, New York, NY, USA.
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3
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Behringer EJ. Impact of aging on vascular ion channels: perspectives and knowledge gaps across major organ systems. Am J Physiol Heart Circ Physiol 2023; 325:H1012-H1038. [PMID: 37624095 PMCID: PMC10908410 DOI: 10.1152/ajpheart.00288.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/21/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Individuals aged ≥65 yr will comprise ∼20% of the global population by 2030. Cardiovascular disease remains the leading cause of death in the world with age-related endothelial "dysfunction" as a key risk factor. As an organ in and of itself, vascular endothelium courses throughout the mammalian body to coordinate blood flow to all other organs and tissues (e.g., brain, heart, lung, skeletal muscle, gut, kidney, skin) in accord with metabolic demand. In turn, emerging evidence demonstrates that vascular aging and its comorbidities (e.g., neurodegeneration, diabetes, hypertension, kidney disease, heart failure, and cancer) are "channelopathies" in large part. With an emphasis on distinct functional traits and common arrangements across major organs systems, the present literature review encompasses regulation of vascular ion channels that underlie blood flow control throughout the body. The regulation of myoendothelial coupling and local versus conducted signaling are discussed with new perspectives for aging and the development of chronic diseases. Although equipped with an awareness of knowledge gaps in the vascular aging field, a section has been included to encompass general feasibility, role of biological sex, and additional conceptual and experimental considerations (e.g., cell regression and proliferation, gene profile analyses). The ultimate goal is for the reader to see and understand major points of deterioration in vascular function while gaining the ability to think of potential mechanistic and therapeutic strategies to sustain organ perfusion and whole body health with aging.
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Affiliation(s)
- Erik J Behringer
- Basic Sciences, Loma Linda University, Loma Linda, California, United States
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4
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Negri S, Sanford M, Shi H, Tarantini S. The role of endothelial TRP channels in age-related vascular cognitive impairment and dementia. Front Aging Neurosci 2023; 15:1149820. [PMID: 37020858 PMCID: PMC10067599 DOI: 10.3389/fnagi.2023.1149820] [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: 01/23/2023] [Accepted: 02/28/2023] [Indexed: 04/07/2023] Open
Abstract
Transient receptor potential (TRP) proteins are part of a superfamily of polymodal cation channels that can be activated by mechanical, physical, and chemical stimuli. In the vascular endothelium, TRP channels regulate two fundamental parameters: the membrane potential and the intracellular Ca2+ concentration [(Ca2+)i]. TRP channels are widely expressed in the cerebrovascular endothelium, and are emerging as important mediators of several brain microvascular functions (e.g., neurovascular coupling, endothelial function, and blood-brain barrier permeability), which become impaired with aging. Aging is the most significant risk factor for vascular cognitive impairment (VCI), and the number of individuals affected by VCI is expected to exponentially increase in the coming decades. Yet, there are currently no preventative or therapeutic treatments available against the development and progression of VCI. In this review, we discuss the involvement of endothelial TRP channels in diverse physiological processes in the brain as well as in the pathogenesis of age-related VCI to explore future potential neuroprotective strategies.
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Affiliation(s)
- Sharon Negri
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Madison Sanford
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Helen Shi
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- *Correspondence: Stefano Tarantini,
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5
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Hakim MA, Behringer EJ. K IR channel regulation of electrical conduction along cerebrovascular endothelium: Enhanced modulation during Alzheimer's disease. Microcirculation 2023; 30:e12797. [PMID: 36577656 PMCID: PMC9885900 DOI: 10.1111/micc.12797] [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: 07/15/2022] [Revised: 11/22/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Endothelial cell (EC) coupling occurs through gap junctions and underlies cerebral blood flow regulation governed by inward-rectifying K+ (KIR ) channels. This study addressed effects of KIR channel activity on EC coupling before and during Alzheimer's disease (AD). METHODS Intact EC tubes (width: ~90-100 μm; length: ~0.5 mm) were freshly isolated from posterior cerebral arteries of young Pre-AD (1-3 months) and aged AD (13-18 months) male and female 3xTg-AD mice. Dual intracellular microelectrodes applied simultaneous current injections (±0.5-3 nA) and membrane potential (Vm ) recordings in ECs at distance ~400 μm. Elevated extracellular potassium ([K+ ]E ; 8-15 mmol/L; reference, 5 mmol/L) activated KIR channels. RESULTS Conducted Vm (∆Vm ) responses ranged from ~-30 to 30 mV in response to -3 to +3 nA (linear regression, R2 ≥ .99) while lacking rectification for charge polarity or axial direction of spread. Conduction slope decreased ~10%-20% during 15 mmol/L [K+ ]E in Pre-AD males and AD females. 15 mmol/L [K+ ]E decreased conduction by ~10%-20% at lower ∆Vm thresholds in AD animals (~±20 mV) versus Pre-AD (~±25 mV). AD increased conducted hyperpolarization by ~10%-15% during 8-12 mmol/L [K+ ]E . CONCLUSIONS Brain endothelial KIR channel activity modulates bidirectional spread of vasoreactive signals with enhanced regulation of EC coupling during AD pathology.
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Affiliation(s)
- Md A. Hakim
- Basic Sciences, Loma Linda University, Loma Linda, CA 92350, USA
| | - Erik J. Behringer
- Basic Sciences, Loma Linda University, Loma Linda, CA 92350, USA,Corresponding Author: Erik J. Behringer, Ph.D., Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, , tel: (909) 651-5334, fax: (909) 558-0119
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6
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Weaver SRC, Rendeiro C, Lucas RAI, Cable NT, Nightingale TE, McGettrick HM, Lucas SJE. Non-pharmacological interventions for vascular health and the role of the endothelium. Eur J Appl Physiol 2022. [PMID: 36149520 DOI: 10.1007/s00421-022-05041-y.pmid:36149520;pmcid:pmc9613570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.
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Affiliation(s)
- Samuel R C Weaver
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.
| | - Catarina Rendeiro
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Rebekah A I Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - N Timothy Cable
- Institute of Sport, Manchester Metropolitan University, Manchester, UK
| | - Tom E Nightingale
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Helen M McGettrick
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Samuel J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
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7
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Weaver SRC, Rendeiro C, Lucas RAI, Cable NT, Nightingale TE, McGettrick HM, Lucas SJE. Non-pharmacological interventions for vascular health and the role of the endothelium. Eur J Appl Physiol 2022; 122:2493-2514. [PMID: 36149520 PMCID: PMC9613570 DOI: 10.1007/s00421-022-05041-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 09/05/2022] [Indexed: 12/11/2022]
Abstract
The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.
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Affiliation(s)
- Samuel R C Weaver
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.
| | - Catarina Rendeiro
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Rebekah A I Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - N Timothy Cable
- Institute of Sport, Manchester Metropolitan University, Manchester, UK
| | - Tom E Nightingale
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Helen M McGettrick
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Samuel J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
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8
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King DR, Sedovy MW, Eaton X, Dunaway LS, Good ME, Isakson BE, Johnstone SR. Cell-To-Cell Communication in the Resistance Vasculature. Compr Physiol 2022; 12:3833-3867. [PMID: 35959755 DOI: 10.1002/cphy.c210040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The arterial vasculature can be divided into large conduit arteries, intermediate contractile arteries, resistance arteries, arterioles, and capillaries. Resistance arteries and arterioles primarily function to control systemic blood pressure. The resistance arteries are composed of a layer of endothelial cells oriented parallel to the direction of blood flow, which are separated by a matrix layer termed the internal elastic lamina from several layers of smooth muscle cells oriented perpendicular to the direction of blood flow. Cells within the vessel walls communicate in a homocellular and heterocellular fashion to govern luminal diameter, arterial resistance, and blood pressure. At rest, potassium currents govern the basal state of endothelial and smooth muscle cells. Multiple stimuli can elicit rises in intracellular calcium levels in either endothelial cells or smooth muscle cells, sourced from intracellular stores such as the endoplasmic reticulum or the extracellular space. In general, activation of endothelial cells results in the production of a vasodilatory signal, usually in the form of nitric oxide or endothelial-derived hyperpolarization. Conversely, activation of smooth muscle cells results in a vasoconstriction response through smooth muscle cell contraction. © 2022 American Physiological Society. Compr Physiol 12: 1-35, 2022.
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Affiliation(s)
- D Ryan King
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Meghan W Sedovy
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | - Xinyan Eaton
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Luke S Dunaway
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Miranda E Good
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Scott R Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
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Hakim MA, Pires PW, Behringer EJ. Isolation and Functional Analysis of Arteriolar Endothelium of Mouse Brain Parenchyma. JOURNAL OF VISUALIZED EXPERIMENTS : JOVE 2022:10.3791/63463. [PMID: 35343953 PMCID: PMC9154351 DOI: 10.3791/63463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cerebral blood flow is conveyed by vascular resistance arteries and downstream parenchymal arterioles. Steady-state vascular resistance to blood flow increases with decreasing diameter from arteries to arterioles that ultimately feed into capillaries. Due to their smaller size and location in the parenchyma, arterioles have been relatively understudied and with less reproducibility in findings than surface pial arteries. Regardless, arteriolar endothelial cell structure and function-integral to the physiology and etiology of chronic degenerative diseases-requires extensive investigation. In particular, emerging evidence demonstrates that compromised endothelial function precedes and exacerbates cognitive impairment and dementia. In the parenchymal microcirculation, endothelial K+ channel function is the most robust stimulus to finely control the spread of vasodilation to promote increases in blood flow to areas of neuronal activity. This paper illustrates a refined method for freshly isolating intact and electrically coupled endothelial "tubes" (diameter, ~25 µm) from mouse brain parenchymal arterioles. Arteriolar endothelial tubes are secured during physiological conditions (37 °C, pH 7.4) to resolve experimental variables that encompass K+ channel function and their regulation, including intracellular Ca2+ dynamics, changes in membrane potential, and membrane lipid regulation. A distinct technical advantage versus arterial endothelium is the enhanced morphological resolution of cell and organelle (e.g., mitochondria) dimensions, which expands the usefulness of this technique. Healthy cerebral perfusion throughout life entails robust endothelial function in parenchymal arterioles, directly linking blood flow to the fueling of neuronal and glial activity throughout precise anatomical regions of the brain. Thus, it is expected that this method will significantly advance the general knowledge of vascular physiology and neuroscience concerning the healthy and diseased brain.
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Affiliation(s)
- Md A. Hakim
- Department of Basic Sciences, Loma Linda University
| | - Paulo W. Pires
- Departments of Physiology, Surgery and Neurosurgery and Sarver Heart Center, University of Arizona College of Medicine Tucson
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10
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Hakim MA, Behringer EJ. Methyl-Beta-Cyclodextrin Restores K IR Channel Function in Brain Endothelium of Female Alzheimer's Disease Mice. J Alzheimers Dis Rep 2021; 5:693-703. [PMID: 34755043 PMCID: PMC8543374 DOI: 10.3233/adr-210016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2021] [Indexed: 12/12/2022] Open
Abstract
Background: As the sixth-leading cause of death in the United States, Alzheimer’s disease (AD) entails deteriorating endothelial control of blood flow throughout the brain. In particular, reduced inward-rectifying K+ (KIR) channel function in animal models of aging and AD compromises endothelial function and optimal perfusion of brain parenchyma. Deficient endothelial KIR channels may result from aberrant interaction with plasma membrane cholesterol as a primary regulator of membrane fluidity and ion channels. Objective: We tested the hypothesis that mild methyl-β-cyclodextrin (MβCD) treatment to reduce membrane cholesterol may restore endothelial KIR channel function in brain endothelium of old AD mice. Methods: Membrane potential was continuously measured in isolated endothelial tubes from posterior cerebral arteries of young (1 to 3 months) and old (16 to 19 months) female 3xTg-AD mice before and after mild treatment with the cholesterol-removing agent MβCD (1 mmol/L). Elevated extracellular potassium ([K+]E; 15 mmol/L) and NS309 (1μmol/L) activated KIR and Ca2+-activated K+ (SKCa/IKCa) channels respectively before and after MβCD treatment. Results: SKCa/IKCa channel function for producing hyperpolarization remained stable regardless of age group and MβCD treatment (ΔVm: ∼–33 mV). However, as deficient during AD, KIR channel function was restored (ΔVm: –9±1 mV) versus pre-MβCD conditions (–5±1 mV); a progressive effect that reached –14±1 mV hyperpolarization at 60 min following MβCD washout. Conclusion: In female animals, MβCD treatment of brain endothelium selectively restores KIR versus SKCa/IKCa channel function during AD. Thus, the endothelial cholesterol-KIR channel interface is a novel target for ameliorating perfusion of the AD brain.
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Affiliation(s)
- Md A Hakim
- Basic Sciences, Loma Linda University, Loma Linda, CA, USA
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11
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Ye L, Sun Y, Jiang Z, Wang G. L-Serine, an Endogenous Amino Acid, Is a Potential Neuroprotective Agent for Neurological Disease and Injury. Front Mol Neurosci 2021; 14:726665. [PMID: 34552468 PMCID: PMC8450333 DOI: 10.3389/fnmol.2021.726665] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/12/2021] [Indexed: 01/02/2023] Open
Abstract
Central nervous system (CNS) lesions are major causes of human death and disability worldwide, and they cause different extents of motor and sensory dysfunction in patients. Thus, it is crucial to develop new effective neuroprotective drugs and approaches targeted to the heterogeneous nature of CNS injury and disease. L-serine is an indispensable neurotrophic factor and a precursor for neurotransmitters. Although L-serine is a native amino acid supplement, its metabolic products have been shown to be essential not only for cell proliferation but also for neuronal development and specific functions in the brain. Growing evidence has suggested that L-serine regulates the release of several cytokines in the brain under some neuropathological conditions to recover cognitive function, improve cerebral blood flow, inhibit inflammation, promote remyelination and exert other neuroprotective effects on neurological injury. L-serine has also been used to treat epilepsy, schizophrenia, psychosis, and Alzheimer’s Disease as well as other neurological diseases. Furthermore, the dosing of animals with L-serine and human clinical trials investigating the therapeutic effects of L-serine generally support the safety of L-serine. The high significance of this review lies in its emphasis on the therapeutic potential of using L-serine as a general treatment for numerous CNS diseases and injuries. Because L-serine performs a broad spectrum of functions, it may be clinically used as an effective neuroprotective agent.
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Affiliation(s)
- Lisha Ye
- Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yechao Sun
- Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Zhenglin Jiang
- Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Guohua Wang
- Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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12
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Anzabi M, Li B, Wang H, Kura S, Sakadžić S, Boas D, Østergaard L, Ayata C. Optical coherence tomography of arteriolar diameter and capillary perfusion during spreading depolarizations. J Cereb Blood Flow Metab 2021; 41:2256-2263. [PMID: 33593116 PMCID: PMC8393288 DOI: 10.1177/0271678x21994013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 12/21/2020] [Accepted: 01/08/2021] [Indexed: 11/17/2022]
Abstract
Spreading depolarization (SD) is associated with profound oligemia and reduced oxygen availability in the mouse cortex during the depolarization phase. Coincident pial arteriolar constriction has been implicated as the primary mechanism for the oligemia. However, where in the vascular bed the hemodynamic response starts has been unclear. To resolve the origin of the hemodynamic response, we used optical coherence tomography (OCT) to simultaneously monitor changes in the vascular tree from capillary bed to pial arteries in mice during two consecutive SDs 15 minutes apart. We found that capillary flow dropped several seconds before pial arteriolar constriction. Moreover, penetrating arterioles constricted before pial arteries suggesting upstream propagation of constriction. Smaller caliber distal pial arteries constricted stronger than larger caliber proximal arterioles, suggesting that the farther the constriction propagates, the weaker it gets. Altogether, our data indicate that the hemodynamic response to cortical SD originates in the capillary bed.
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Affiliation(s)
- Maryam Anzabi
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
- Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Baoqiang Li
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences
| | - Hui Wang
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Sreekanth Kura
- Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Sava Sakadžić
- Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - David Boas
- Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, USA
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13
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Cripps SM, Mattiske DM, Pask AJ. Erectile Dysfunction in Men on the Rise: Is There a Link with Endocrine Disrupting Chemicals? Sex Dev 2021; 15:187-212. [PMID: 34134123 DOI: 10.1159/000516600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/18/2021] [Indexed: 11/19/2022] Open
Abstract
Erectile dysfunction (ED) is one of the most prevalent chronic conditions affecting men. ED can arise from disruptions during development, affecting the patterning of erectile tissues in the penis and/or disruptions in adulthood that impact sexual stimuli, neural pathways, molecular changes, and endocrine signalling that are required to drive erection. Sexual stimulation activates the parasympathetic system which causes nerve terminals in the penis to release nitric oxide (NO). As a result, the penile blood vessels dilate, allowing the penis to engorge with blood. This expansion subsequently compresses the veins surrounding the erectile tissue, restricting venous outflow. As a result, the blood pressure localised in the penis increases dramatically to produce a rigid erection, a process known as tumescence. The sympathetic pathway releases noradrenaline (NA) which causes detumescence: the reversion of the penis to the flaccid state. Androgen signalling is critical for erectile function through its role in penis development and in regulating the physiological processes driving erection in the adult. Interestingly, estrogen signalling is also implicated in penis development and potentially in processes which regulate erectile function during adulthood. Given that endocrine signalling has a prominent role in erectile function, it is likely that exposure to endocrine disrupting chemicals (EDCs) is a risk factor for ED, although this is an under-researched field. Thus, our review provides a detailed description of the underlying biology of erectile function with a focus on the role of endocrine signalling, exploring the potential link between EDCs and ED based on animal and human studies.
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Affiliation(s)
- Samuel M Cripps
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Deidre M Mattiske
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew J Pask
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
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Hakim MA, Behringer EJ. Development of Alzheimer's Disease Progressively Alters Sex-Dependent KCa and Sex-Independent KIR Channel Function in Cerebrovascular Endothelium. J Alzheimers Dis 2021; 76:1423-1442. [PMID: 32651315 DOI: 10.3233/jad-200085] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Development of Alzheimer's disease (AD) pathology is associated with impaired blood flow delivery of oxygen and nutrients throughout the brain. Cerebrovascular endothelium regulates vasoreactivity of blood vessel networks for optimal cerebral blood flow. OBJECTIVE We tested the hypothesis that cerebrovascular endothelial Gq-protein-coupled receptor (GPCR; purinergic and muscarinic) and K+ channel [Ca2+-activated (KCa2.3/SK3 and KCa3.1/IK1) and inward-rectifying (KIR2.x)] function declines during progressive AD pathology. METHODS We applied simultaneous measurements of intracellular Ca2+ ([Ca2+]i) and membrane potential (Vm) in freshly isolated endothelium from posterior cerebral arteries of 3×Tg-AD mice [young, no pathology (1- 2 mo), cognitive impairment (CI; 4- 5 mo), extracellular Aβ plaques (Aβ; 6- 8 mo), and Aβ plaques + neurofibrillary tangles (AβT; 12- 15 mo)]. RESULTS The coupling of ΔVm-to-Δ[Ca2+]i during AβT pathology was lowest for both sexes but, overall, ATP-induced purinergic receptor function was stable throughout AD pathology. SKCa/IKCa channel function itself was enhanced by ∼20% during AD (Aβ+ AβT) versus pre-AD (Young + CI) in males while steady in females. Accordingly, hyperpolarization-induced [Ca2+]i increases following SKCa/IKCa channel activation and Δ[Ca2+]i-to-ΔVm coupling was enhanced by ≥two-fold during AD pathology in males but not females. Further, KIR channel function decreased by ∼50% during AD conditions versus young regardless of sex. Finally, other than a ∼40% increase in females versus males during Aβ pathology, [Ca2+]i responses to the mitochondrial uncoupler FCCP were similar among AD versus pre-AD conditions. CONCLUSION Altogether, AD pathology represents a condition of altered KCa and KIR channel function in cerebrovascular endothelium in a sex-dependent and sex-independent manner respectively.
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Affiliation(s)
- Md A Hakim
- Basic Sciences, Loma Linda University, Loma Linda, CA, USA
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15
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Hakim MA, Chum PP, Buchholz JN, Behringer EJ. Aging Alters Cerebrovascular Endothelial GPCR and K+ Channel Function: Divergent Role of Biological Sex. J Gerontol A Biol Sci Med Sci 2021; 75:2064-2073. [PMID: 31760422 DOI: 10.1093/gerona/glz275] [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: 08/20/2019] [Indexed: 12/11/2022] Open
Abstract
Age-related dementia entails impaired blood flow to and throughout the brain due, in part, to reduced endothelial nitric oxide signaling. However, it is unknown whether sex affects cerebrovascular Gq-protein-coupled receptors (GPCRs) and K+ channels underlying endothelium-derived hyperpolarization (EDH) during progressive aging. Thus, we simultaneously evaluated intracellular Ca2+ ([Ca2+]i) and membrane potential (Vm) of intact endothelial tubes freshly isolated from posterior cerebral arteries of young (4-6 mo), middle-aged (12-16 mo), and old (24-28 mo) male and female C57BL/6 mice. Purinergic receptor function (vs. muscarinic) was dominant and enhanced for [Ca2+]i increases in old females versus old males. However, Ca2+-sensitive K+ channel function as defined by NS309-evoked Vm hyperpolarization was mildly impaired in females versus males during old age. This sex-based contrast in declined function of GPCRs and K+ channels to produce EDH may support a greater ability for physiological endothelial GPCR function to maintain optimal cerebral blood flow in females versus males during old age. As reflective of the pattern of cerebral blood flow decline in human subjects, inward-rectifying K+ (KIR) channel function decreased with progressive age regardless of sex. Combined age-related analyses masked male versus female aging and, contrary to expectation, hydrogen peroxide played a minimal role. Altogether, we conclude a sex-based divergence in cerebrovascular endothelial GPCR and K+ channel function while highlighting a previously unidentified form of age-related endothelial dysfunction as reduced KIR channel function.
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Affiliation(s)
- Md A Hakim
- Basic Sciences, Loma Linda University, California
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16
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Feng J, Liu L, Yao F, Zhou D, He Y, Wang J. The protective effect of tanshinone IIa on endothelial cells: a generalist among clinical therapeutics. Expert Rev Clin Pharmacol 2021; 14:239-248. [PMID: 33463381 DOI: 10.1080/17512433.2021.1878877] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Tanshinone IIa (TSA) has been approved to treat cardiovascular diseases by the China State Food and Drug Administration. TSA has exhibited a variety of pharmacological effects, including vasodilator, antioxidant, anti-inflammatory, and anti-tumor properties. Endothelial cells play an important physiological role in vascular homeostasis and control inflammation, coagulation, and thrombosis. Accumulating studies have shown that TSA can improve endothelial function through various pathways. AREAS COVERED The PubMed database was reviewed for relevant papers published up to 2020. This review summarizes the current clinical and pharmaceutical studies to provide a systemic overview of the pharmacological and therapeutic effects of TSA on endothelial cells. EXPERT OPINION TSA is a representative monomeric compound extracted from Danshen and it exhibits significant pharmacological and therapeutic properties to improve endothelial cell function, including alleviating oxidative stress, attenuating inflammatory injury, modulating ion channels and so on. TSA represents a spectrum of agents that are extracted from plants and can restore the endothelial function to establish the beneficial and harmless molecular therapeutics. This also suggests the possible detection of endothelial cells for very early diagnosis of diseases. In future, precise therapeutic methods will be developed to repair endothelial cells injury and recover endothelial dysfunction.
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Affiliation(s)
- Jun Feng
- Department of Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Lina Liu
- Department of Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fangfang Yao
- Department of Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Daixing Zhou
- Department of Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Yang He
- Department of Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Junshuai Wang
- Department of Critical Care Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
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Kim MK, Han AY, Shin YK, Lee KW, Seol GH. Codonopsis lanceolata Contributes to Ca2+ Homeostasis by Mediating SOCE and PLC/IP3 Pathways in Vascular Endothelial and Smooth Muscle Cells. PLANTA MEDICA 2020; 86:1345-1352. [PMID: 32731264 DOI: 10.1055/a-1214-6718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Codonopsis lanceolata has been widely used as an anti-inflammatory and anti-lipogenic agent in traditional medicine. Recently, C. lanceolata was reported to prevent hypertension by improving vascular function. This study evaluated the effects of C. lanceolata and its major component lancemaside A on cytosolic calcium concentration in vascular endothelial cells and vascular smooth muscle cells. Cytosolic calcium concentration was measured using fura-2 AM fluorescence. C. lanceolata or lancemaside A increased the cytosolic calcium concentration by releasing Ca2+ from the endoplasmic reticulum and sarcoplasmic reticulum and by Ca2+ entry into endothelial cells and vascular smooth muscle cells from extracellular sources. The C. lanceolata- and lancemaside A-induced cytosolic calcium concentration increases were significantly inhibited by lanthanum, an inhibitor of non-selective cation channels, in both endothelial cells and vascular smooth muscle cells. Moreover, C. lanceolata and lancemaside A significantly inhibited store-operated Ca2+ entry under pathological extracellular Ca2+ levels. In Ca2+-free extracellular fluid, increases in the cytosolic calcium concentration induced by C. lanceolata or lancemaside A were significantly inhibited by U73122, an inhibitor of phospholipase C, and 2-APB, an inositol 1,4,5-trisphosphate receptor antagonist. In addition, dantrolene treatment, which inhibits Ca2+ release through ryanodine receptor channels, also inhibited C. lanceolata- or lancemaside A-induced increases in the cytosolic calcium concentration through the phospholipase C/inositol 1,4,5-trisphosphate pathway. These results suggest that C. lanceolata and lancemaside A increase the cytosolic calcium concentration through the non-selective cation channels and phospholipase C/inositol 1,4,5-trisphosphate pathways under physiological conditions and inhibit store-operated Ca2+ entry under pathological conditions in endothelial cells and vascular smooth muscle cells. C. lanceolata or lancemaside A can protect endothelial cells and vascular smooth muscle cells by maintaining cytosolic calcium concentration homeostasis, suggesting possible applications for these materials in diets for preventing vascular damage.
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Affiliation(s)
- Min Kyung Kim
- Department of Basic Nursing Science, College of Nursing, Korea University, Seoul, Republic of Korea
| | - A Young Han
- Department of Basic Nursing Science, College of Nursing, Korea University, Seoul, Republic of Korea
| | - You Kyoung Shin
- Department of Basic Nursing Science, College of Nursing, Korea University, Seoul, Republic of Korea
| | - Kwang-Won Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Geun Hee Seol
- Department of Basic Nursing Science, College of Nursing, Korea University, Seoul, Republic of Korea
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18
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Disambiguating the role of blood flow and global signal with partial information decomposition. Neuroimage 2020; 213:116699. [PMID: 32179104 DOI: 10.1016/j.neuroimage.2020.116699] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/24/2020] [Accepted: 02/29/2020] [Indexed: 12/12/2022] Open
Abstract
Global signal (GS) is an ubiquitous construct in resting state functional magnetic resonance imaging (rs-fMRI), associated to nuisance, but containing by definition most of the neuronal signal. Global signal regression (GSR) effectively removes the impact of physiological noise and other artifacts, but at the same time it alters correlational patterns in unpredicted ways. Performing GSR taking into account the underlying physiology (mainly the blood arrival time) has been proven to be beneficial. From these observations we aimed to: 1) characterize the effect of GSR on network-level functional connectivity in a large dataset; 2) assess the complementary role of global signal and vessels; and 3) use the framework of partial information decomposition to further look into the joint dynamics of the global signal and vessels, and their respective influence on the dynamics of cortical areas. We observe that GSR affects intrinsic connectivity networks in the connectome in a non-uniform way. Furthermore, by estimating the predictive information of blood flow and the global signal using partial information decomposition, we observe that both signals are present in different amounts across intrinsic connectivity networks. Simulations showed that differences in blood arrival time can largely explain this phenomenon, while using hemodynamic and calcium mouse recordings we were able to confirm the presence of vascular effects, as calcium recordings lack hemodynamic information. With these results we confirm network-specific effects of GSR and the importance of taking blood flow into account for improving de-noising methods. Additionally, and beyond the mere issue of data denoising, we quantify the diverse and complementary effect of global and vessel BOLD signals on the dynamics of cortical areas.
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Moccia F, Negri S, Faris P, Berra-Romani R. Targeting the Endothelial Ca2+ Toolkit to Rescue Endothelial Dysfunction in Obesity Associated-Hypertension. Curr Med Chem 2020; 27:240-257. [PMID: 31486745 DOI: 10.2174/0929867326666190905142135] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/03/2019] [Accepted: 07/16/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Obesity is a major cardiovascular risk factor which dramatically impairs endothelium- dependent vasodilation and leads to hypertension and vascular damage. The impairment of the vasomotor response to extracellular autacoids, e.g., acetylcholine, mainly depends on the reduced Nitric Oxide (NO) bioavailability, which hampers vasorelaxation in large conduit arteries. In addition, obesity may affect Endothelium-Dependent Hyperpolarization (EDH), which drives vasorelaxation in small resistance arteries and arterioles. Of note, endothelial Ca2+ signals drive NO release and trigger EDH. METHODS A structured search of bibliographic databases was carried out to retrieve the most influential, recent articles on the impairment of vasorelaxation in animal models of obesity, including obese Zucker rats, and on the remodeling of the endothelial Ca2+ toolkit under conditions that mimic obesity. Furthermore, we searched for articles discussing how dietary manipulation could be exploited to rescue Ca2+-dependent vasodilation. RESULTS We found evidence that the endothelial Ca2+ could be severely affected by obese vessels. This rearrangement could contribute to endothelial damage and is likely to be involved in the disruption of vasorelaxant mechanisms. However, several Ca2+-permeable channels, including Vanilloid Transient Receptor Potential (TRPV) 1, 3 and 4 could be stimulated by several food components to stimulate vasorelaxation in obese individuals. CONCLUSION The endothelial Ca2+ toolkit could be targeted to reduce vascular damage and rescue endothelium- dependent vasodilation in obese vessels. This hypothesis remains, however, to be probed on truly obese endothelial cells.
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Affiliation(s)
- Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Sharon Negri
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Pawan Faris
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Roberto Berra-Romani
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
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20
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Berra-Romani R, Faris P, Pellavio G, Orgiu M, Negri S, Forcaia G, Var-Gaz-Guadarrama V, Garcia-Carrasco M, Botta L, Sancini G, Laforenza U, Moccia F. Histamine induces intracellular Ca 2+ oscillations and nitric oxide release in endothelial cells from brain microvascular circulation. J Cell Physiol 2019; 235:1515-1530. [PMID: 31310018 DOI: 10.1002/jcp.29071] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 06/21/2019] [Indexed: 02/06/2023]
Abstract
The neuromodulator histamine is able to vasorelax in human cerebral, meningeal and temporal arteries via endothelial histamine 1 receptors (H1 Rs) which result in the downstream production of nitric oxide (NO), the most powerful vasodilator transmitter in the brain. Although endothelial Ca 2+ signals drive histamine-induced NO release throughout the peripheral circulation, the mechanism by which histamine evokes NO production in human cerebrovascular endothelial cells is still unknown. Herein, we exploited the human cerebral microvascular endothelial cell line, hCMEC/D3, to assess the role of intracellular Ca 2+ signaling in histamine-induced NO release. To achieve this goal, hCMEC/D3 cells were loaded with the Ca 2+ - and NO-sensitive dyes, Fura-2/AM and DAF-FM/AM, respectively. Histamine elicited repetitive oscillations in intracellular Ca 2+ concentration in hCMEC/D3 cells throughout a concentration range spanning from 1 pM up to 300 μM. The oscillatory Ca 2+ response was suppressed by the inhibition of H 1 Rs with pyrilamine, whereas H 1 R was abundantly expressed at the protein level. We further found that histamine-induced intracellular Ca 2+ oscillations were initiated by endogenous Ca 2+ mobilization through inositol-1,4,5-trisphosphate- and nicotinic acid dinucleotide phosphate-sensitive channels and maintained over time by store-operated Ca 2+ entry. In addition, histamine evoked robust NO release that was prevented by interfering with the accompanying intracellular Ca 2+ oscillations, thereby confirming that the endothelial NO synthase is recruited by Ca 2+ spikes also in hCMEC/D3 cells. These data provide the first evidence that histamine evokes NO production from human cerebrovascular endothelial cells through intracellular Ca 2+ oscillations, thereby shedding novel light on the mechanisms by which this neuromodulator controls cerebral blood flow.
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Affiliation(s)
- Roberto Berra-Romani
- Department of Biomedicine, Biomedicine School, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
| | - Pawan Faris
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy.,Research Center, Salahaddin University, Erbil, Kurdistan-Region of Iraq, Iraq
| | - Giorgia Pellavio
- Human Physiology Unit, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Matteo Orgiu
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Sharon Negri
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Greta Forcaia
- Department of Experimental Medicine, University of Milano-Bicocca, Monza, Italy
| | | | - Mario Garcia-Carrasco
- Department of Biomedicine, Biomedicine School, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
| | - Laura Botta
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
| | - Giulio Sancini
- Department of Experimental Medicine, University of Milano-Bicocca, Monza, Italy
| | - Umberto Laforenza
- Human Physiology Unit, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, Pavia, Italy
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Behringer EJ, Hakim MA. Functional Interaction among K Ca and TRP Channels for Cardiovascular Physiology: Modern Perspectives on Aging and Chronic Disease. Int J Mol Sci 2019; 20:ijms20061380. [PMID: 30893836 PMCID: PMC6471369 DOI: 10.3390/ijms20061380] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/07/2019] [Accepted: 03/15/2019] [Indexed: 12/16/2022] Open
Abstract
Effective delivery of oxygen and essential nutrients to vital organs and tissues throughout the body requires adequate blood flow supplied through resistance vessels. The intimate relationship between intracellular calcium ([Ca2+]i) and regulation of membrane potential (Vm) is indispensable for maintaining blood flow regulation. In particular, Ca2+-activated K+ (KCa) channels were ascertained as transducers of elevated [Ca2+]i signals into hyperpolarization of Vm as a pathway for decreasing vascular resistance, thereby enhancing blood flow. Recent evidence also supports the reverse role for KCa channels, in which they facilitate Ca2+ influx into the cell interior through open non-selective cation (e.g., transient receptor potential; TRP) channels in accord with robust electrical (hyperpolarization) and concentration (~20,000-fold) transmembrane gradients for Ca2+. Such an arrangement supports a feed-forward activation of Vm hyperpolarization while potentially boosting production of nitric oxide. Furthermore, in vascular types expressing TRP channels but deficient in functional KCa channels (e.g., collecting lymphatic endothelium), there are profound alterations such as downstream depolarizing ionic fluxes and the absence of dynamic hyperpolarizing events. Altogether, this review is a refined set of evidence-based perspectives focused on the role of the endothelial KCa and TRP channels throughout multiple experimental animal models and vascular types. We discuss the diverse interactions among KCa and TRP channels to integrate Ca2+, oxidative, and electrical signaling in the context of cardiovascular physiology and pathology. Building from a foundation of cellular biophysical data throughout a wide and diverse compilation of significant discoveries, a translational narrative is provided for readers toward the treatment and prevention of chronic, age-related cardiovascular disease.
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Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Md A Hakim
- Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, USA.
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22
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Hakim MA, Behringer EJ. Simultaneous Measurements of Intracellular Calcium and Membrane Potential in Freshly Isolated and Intact Mouse Cerebral Endothelium. J Vis Exp 2019. [PMID: 30735188 DOI: 10.3791/58832] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cerebral arteries and their respective microcirculation deliver oxygen and nutrients to the brain via blood flow regulation. Endothelial cells line the lumen of blood vessels and command changes in vascular diameter as needed to meet the metabolic demand of neurons. Primary endothelial-dependent signaling pathways of hyperpolarization of membrane potential (Vm) and nitric oxide typically operate in parallel to mediate vasodilation and thereby increase blood flow. Although integral to coordinating vasodilation over several millimeters of vascular length, components of endothelium-derived hyperpolarization (EDH) have been historically difficult to measure. These components of EDH entail intracellular Ca2+ [Ca2+]i increases and subsequent activation of small- and intermediate conductance Ca2+-activated K+ (SKCa/IKCa) channels. Here, we present a simplified illustration of the isolation of fresh endothelium from mouse cerebral arteries; simultaneous measurements of endothelial [Ca2+]i and Vm using Fura-2 photometry and intracellular sharp electrodes, respectively; and a continuous superfusion of salt solutions and pharmacological agents under physiological conditions (pH 7.4, 37 °C). Posterior cerebral arteries from the Circle of Willis are removed free of the posterior communicating and the basilar arteries. Enzymatic digestion of cleaned posterior cerebral arterial segments and subsequent trituration facilitates removal of adventitia, perivascular nerves, and smooth muscle cells. Resulting posterior cerebral arterial endothelial "tubes" are then secured under a microscope and examined using a camera, photomultiplier tube, and one to two electrometers while under continuous superfusion. Collectively, this method can simultaneously measure changes in endothelial [Ca2+]i and Vm in discrete cellular locations, in addition to the spreading of EDH through gap junctions up to millimeter distances along the intact endothelium. This method is expected to yield a high-throughput analysis of the cerebral endothelial functions underlying mechanisms of blood flow regulation in the normal and diseased brain.
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Affiliation(s)
- Md A Hakim
- Department of Basic Sciences, Loma Linda University
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23
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Pogoda K, Kameritsch P, Mannell H, Pohl U. Connexins in the control of vasomotor function. Acta Physiol (Oxf) 2019; 225:e13108. [PMID: 29858558 DOI: 10.1111/apha.13108] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 12/13/2022]
Abstract
Vascular endothelial cells, as well as smooth muscle cells, show heterogeneity with regard to their receptor expression and reactivity. For the vascular wall to act as a functional unit, the various cells' responses require integration. Such an integration is not only required for a homogeneous response of the vascular wall, but also for the vasomotor behaviour of consecutive segments of the microvascular arteriolar tree. As flow resistances of individual sections are connected in series, sections require synchronization and coordination to allow effective changes of conductivity and blood flow. A prerequisite for the local coordination of individual vascular cells and different sections of an arteriolar tree is intercellular communication. Connexins are involved in a dual manner in this coordination. (i) By forming gap junctions between cells, they allow an intercellular exchange of signalling molecules and electrical currents. In particular, the spread of electrical currents allows for coordination of cell responses over longer distances. (ii) Connexins are able to interact with other proteins to form signalling complexes. In this way, they can modulate and integrate individual cells' responses also in a channel-independent manner. This review outlines mechanisms allowing the vascular connexins to exert their coordinating function and to regulate the vasomotor reactions of blood vessels both locally, and in vascular networks. Wherever possible, we focus on the vasomotor behaviour of small vessels and arterioles which are the main vessels determining vascular resistance, blood pressure and local blood flow.
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Affiliation(s)
- K. Pogoda
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
| | - P. Kameritsch
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
| | - H. Mannell
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
| | - U. Pohl
- Walter-Brendel-Centre of Experimental Medicine; University Hospital; LMU Munich; Munich Germany
- Biomedical Center; Cardiovascular Physiology; LMU Munich; Munich Germany
- DZHK (German Center for Cardiovascular Research); Partner Site Munich Heart Alliance; Munich Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich Germany
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Zuccolo E, Kheder DA, Lim D, Perna A, Nezza FD, Botta L, Scarpellino G, Negri S, Martinotti S, Soda T, Forcaia G, Riboni L, Ranzato E, Sancini G, Ambrosone L, D'Angelo E, Guerra G, Moccia F. Glutamate triggers intracellular Ca 2+ oscillations and nitric oxide release by inducing NAADP- and InsP 3 -dependent Ca 2+ release in mouse brain endothelial cells. J Cell Physiol 2018; 234:3538-3554. [PMID: 30451297 DOI: 10.1002/jcp.26953] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/13/2018] [Indexed: 12/13/2022]
Abstract
The neurotransmitter glutamate increases cerebral blood flow by activating postsynaptic neurons and presynaptic glial cells within the neurovascular unit. Glutamate does so by causing an increase in intracellular Ca2+ concentration ([Ca2+ ]i ) in the target cells, which activates the Ca2+ /Calmodulin-dependent nitric oxide (NO) synthase to release NO. It is unclear whether brain endothelial cells also sense glutamate through an elevation in [Ca2+ ]i and NO production. The current study assessed whether and how glutamate drives Ca2+ -dependent NO release in bEND5 cells, an established model of brain endothelial cells. We found that glutamate induced a dose-dependent oscillatory increase in [Ca2+ ]i , which was maximally activated at 200 μM and inhibited by α-methyl-4-carboxyphenylglycine, a selective blocker of Group 1 metabotropic glutamate receptors. Glutamate-induced intracellular Ca2+ oscillations were triggered by rhythmic endogenous Ca2+ mobilization and maintained over time by extracellular Ca2+ entry. Pharmacological manipulation revealed that glutamate-induced endogenous Ca2+ release was mediated by InsP3 -sensitive receptors and nicotinic acid adenine dinucleotide phosphate (NAADP) gated two-pore channel 1. Constitutive store-operated Ca2+ entry mediated Ca2+ entry during ongoing Ca2+ oscillations. Finally, glutamate evoked a robust, although delayed increase in NO levels, which was blocked by pharmacologically inhibition of the accompanying intracellular Ca2+ signals. Of note, glutamate induced Ca2+ -dependent NO release also in hCMEC/D3 cells, an established model of human brain microvascular endothelial cells. This investigation demonstrates for the first time that metabotropic glutamate-induced intracellular Ca2+ oscillations and NO release have the potential to impact on neurovascular coupling in the brain.
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Affiliation(s)
- Estella Zuccolo
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani," University of Pavia, Pavia, Italy
| | - Dlzar A Kheder
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani," University of Pavia, Pavia, Italy.,Department of Biology, University of Zakho, Duhok, Kurdistan-Region of Iraq
| | - Dmitry Lim
- Department of Pharmaceutical Sciences, University of Eastern Piedmont "Amedeo Avogadro,", Novara, Italy
| | - Angelica Perna
- Department of Medicine and Health Sciences "Vincenzo Tiberio,", University of Molise, Campobasso, Italy
| | - Francesca Di Nezza
- Department of Bioscience and Territory (DIBT), University of Molise, Contrada Lappone Pesche, Isernia, Italy
| | - Laura Botta
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani," University of Pavia, Pavia, Italy
| | - Giorgia Scarpellino
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani," University of Pavia, Pavia, Italy
| | - Sharon Negri
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani," University of Pavia, Pavia, Italy
| | - Simona Martinotti
- Dipartimento di Scienze e Innovazione Tecnologica (DiSIT), University of Piemonte Orientale, Alessandria, Italy
| | - Teresa Soda
- Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Rome, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Greta Forcaia
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Laura Riboni
- Department of Medical Biotechnology and Translational Medicine, LITA-Segrate, University of Milan, Segrate, Milan, Italy
| | - Elia Ranzato
- Dipartimento di Scienze e Innovazione Tecnologica (DiSIT), University of Piemonte Orientale, Alessandria, Italy
| | - Giulio Sancini
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Luigi Ambrosone
- Department of Medicine and Health Sciences "Vincenzo Tiberio,", Centre of Nanomedicine, University of Molise, Campobasso, Italy
| | - Egidio D'Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.,Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy
| | - Germano Guerra
- Department of Medicine and Health Sciences "Vincenzo Tiberio,", University of Molise, Campobasso, Italy
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani," University of Pavia, Pavia, Italy
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Automated Intracellular Calcium Profiles Extraction from Endothelial Cells Using Digital Fluorescence Images. Int J Mol Sci 2018; 19:ijms19113440. [PMID: 30400174 PMCID: PMC6274978 DOI: 10.3390/ijms19113440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 01/13/2023] Open
Abstract
Endothelial cells perform a wide variety of fundamental functions for the cardiovascular system, their proliferation and migration being strongly regulated by their intracellular calcium concentration. Hence it is extremely important to carefully measure endothelial calcium signals under different stimuli. A proposal to automate the intracellular calcium profiles extraction from fluorescence image sequences is presented. Digital image processing techniques were combined with a multi-target tracking approach supported by Kalman estimation. The system was tested with image sequences from two different stimuli. The first one was a chemical stimulus, that is, ATP, which caused small movements in the cells trajectories, thereby suggesting that the bath application of the agonist does not generate significant artifacts. The second one was a mechanical stimulus delivered by a glass microelectrode, which caused major changes in cell trajectories. The importance of the tracking block is evidenced since more accurate profiles were extracted, mainly for cells closest to the stimulated area. Two important contributions of this work are the automatic relocation of the region of interest assigned to the cells and the possibility of data extraction from big image sets in efficient and expedite way. The system may adapt to different kind of cell images and may allow the extraction of other useful features.
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26
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Hakim MA, Buchholz JN, Behringer EJ. Electrical dynamics of isolated cerebral and skeletal muscle endothelial tubes: Differential roles of G-protein-coupled receptors and K + channels. Pharmacol Res Perspect 2018; 6:e00391. [PMID: 29636977 PMCID: PMC5889193 DOI: 10.1002/prp2.391] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/12/2018] [Indexed: 12/13/2022] Open
Abstract
Electrical dynamics of freshly isolated cerebral endothelium have not been determined independently of perivascular nerves and smooth muscle. We tested the hypothesis that endothelium of cerebral and skeletal muscle arteries differentially utilizes purinergic and muscarinic signaling pathways to activate endothelium‐derived hyperpolarization. Changes in membrane potential (Vm) were recorded in intact endothelial tubes freshly isolated from posterior cerebral and superior epigastric arteries of male and female C57BL/6 mice (age: 3‐8 months). Vm was measured in response to activation of purinergic (P2Y) and muscarinic (M3) receptors in addition to small‐ and intermediate‐conductance Ca2+‐activated K+ (SKCa/IKCa) and inward rectifying K+ (KIR) channels using ATP (100 μmol·L−1), acetylcholine (ACh; 10 μmol·L−1), NS309 (0.01‐10 μmol·L−1), and 15 mmol·L−1 KCl, respectively. Intercellular coupling was demonstrated via transfer of propidium iodide dye and electrical current (±0.5‐3 nA) through gap junctions. With similarities observed across gender, peak hyperpolarization to ATP and ACh in skeletal muscle endothelial tubes was ~twofold and ~sevenfold higher, respectively, vs cerebral endothelial tubes, whereas responses to NS309 were similar (from resting Vm ~−30 mV to maximum ~−80 mV). Hyperpolarization (~8 mV) occurred during 15 mmol·L−1 KCl treatment in cerebral but not skeletal muscle endothelial tubes. Despite weaker hyperpolarization during endothelial GPCR stimulation in cerebral vs skeletal muscle endothelium, the capability for robust SKCa/IKCa activity is preserved across brain and skeletal muscle. As vascular reactivity decreases with aging and cardiovascular disease, endothelial K+ channel activity may be calibrated to restore blood flow to respective organs regardless of gender.
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Affiliation(s)
- Md A Hakim
- Basic Sciences Loma Linda University Loma Linda CA USA
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Guerra G, Lucariello A, Perna A, Botta L, De Luca A, Moccia F. The Role of Endothelial Ca 2+ Signaling in Neurovascular Coupling: A View from the Lumen. Int J Mol Sci 2018; 19:E938. [PMID: 29561829 PMCID: PMC5979341 DOI: 10.3390/ijms19040938] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Neurovascular coupling (NVC) is the mechanism whereby an increase in neuronal activity (NA) leads to local elevation in cerebral blood flow (CBF) to match the metabolic requirements of firing neurons. Following synaptic activity, an increase in neuronal and/or astrocyte Ca2+ concentration leads to the synthesis of multiple vasoactive messengers. Curiously, the role of endothelial Ca2+ signaling in NVC has been rather neglected, although endothelial cells are known to control the vascular tone in a Ca2+-dependent manner throughout peripheral vasculature. METHODS We analyzed the literature in search of the most recent updates on the potential role of endothelial Ca2+ signaling in NVC. RESULTS We found that several neurotransmitters (i.e., glutamate and acetylcholine) and neuromodulators (e.g., ATP) can induce dilation of cerebral vessels by inducing an increase in endothelial Ca2+ concentration. This, in turn, results in nitric oxide or prostaglandin E2 release or activate intermediate and small-conductance Ca2+-activated K⁺ channels, which are responsible for endothelial-dependent hyperpolarization (EDH). In addition, brain endothelial cells express multiple transient receptor potential (TRP) channels (i.e., TRPC3, TRPV3, TRPV4, TRPA1), which induce vasodilation by activating EDH. CONCLUSIONS It is possible to conclude that endothelial Ca2+ signaling is an emerging pathway in the control of NVC.
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Affiliation(s)
- Germano Guerra
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, via F. De Santis, 86100 Campobasso, Italy.
| | - Angela Lucariello
- Department of Mental Health and Preventive Medicine, Section of Human Anatomy, University of Campania "L. Vanvitelli", 81100 Naples, Italy.
| | - Angelica Perna
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, via F. De Santis, 86100 Campobasso, Italy.
| | - Laura Botta
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Forlanini 6, 27100 Pavia, Italy.
| | - Antonio De Luca
- Department of Mental Health and Preventive Medicine, Section of Human Anatomy, University of Campania "L. Vanvitelli", 81100 Naples, Italy.
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Forlanini 6, 27100 Pavia, Italy.
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28
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Dobson GP, Arsyad A, Letson HL. The Adenosine Hypothesis Revisited: Modulation of Coupling between Myocardial Perfusion and Arterial Compliance. Front Physiol 2017; 8:824. [PMID: 29104545 PMCID: PMC5654924 DOI: 10.3389/fphys.2017.00824] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/06/2017] [Indexed: 12/25/2022] Open
Abstract
For over four decades the thoracic aortic ring model has become one of the most widely used methods to study vascular reactivity and electromechanical coupling. A question that is rarely asked, however, is what function does a drug-mediated relaxation (or contraction) in this model serve in the intact system? The physiological significance of adenosine relaxation in rings isolated from large elastic conduit arteries from a wide range of species remains largely unknown. We propose that adenosine relaxation increases aortic compliance in acute stress states and facilitates ventricular-arterial (VA) coupling, and thereby links compliance and coronary artery perfusion to myocardial energy metabolism. In 1963 Berne argued that adenosine acts as a local negative feedback regulator between oxygen supply and demand in the heart during hypoxic/ischemic stress. The adenosine VA coupling hypothesis extends and enhances Berne's "adenosine hypothesis" from a local regulatory scheme in the heart to include conduit arterial function. In multicellular organisms, evolution may have selected adenosine, nitric oxide, and other vascular mediators, to modulate VA coupling for optimal transfer of oxygen (and nutrients) from the lung, heart, large conduit arteries, arterioles and capillaries to respiring mitochondria. Finally, a discussion of the potential clinical significance of adenosine modulation of VA coupling is extended to vascular aging and disease, including hypertension, diabetes, obesity, coronary artery disease and heart failure.
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Affiliation(s)
- Geoffrey P Dobson
- Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia
| | - Aryadi Arsyad
- Physiology Department, Medical Faculty, Hasanuddin University, Makassar, Indonesia
| | - Hayley L Letson
- Heart, Trauma and Sepsis Research Laboratory, College of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia
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29
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Welsh DG, Longden TA. Endothelial signaling and the dynamic regulation of arterial tone: A surreptitious relationship. Microcirculation 2017; 24. [PMID: 28303623 DOI: 10.1111/micc.12370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 03/11/2017] [Indexed: 12/20/2022]
Abstract
The endothelium is an integrated layer of cells whose dynamic regulation governs arterial tone development and the matching of blood flow delivery to tissue energetic demand. Investigating the structural and electrical properties of native endothelial cells has been a challenging prospect, with efforts often restricted to traditional myographic techniques. Concerted experimental attention, along with recent technical advances, has broadened the investigative tool kit, deepening mechanistic insights. This overview in part of a STI centered on the endothelium and how key structural/electrical properties guide arterial tone development and integrated network behavior. Articles are written in a provocative, opinionated manner to provoke deeper thought and to highlight areas of investigative deficiency.
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Affiliation(s)
- Donald G Welsh
- Robarts Research Institute, Department of Physiology & Pharmacology, Schulich School of Medicine, University of Western Ontario, London, Ontario, Canada
| | - Thomas A Longden
- Department of Pharmacology, Faculty of Medicine, University of Vermont, Burlington, Vermont, USA
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