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Halvorson BD, Ward AD, Murrell D, Lacefield JC, Wiseman RW, Goldman D, Frisbee JC. Regulation of Skeletal Muscle Resistance Arteriolar Tone: Temporal Variability in Vascular Responses. J Vasc Res 2024:1-29. [PMID: 39362208 DOI: 10.1159/000541169] [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: 06/27/2024] [Accepted: 08/25/2024] [Indexed: 10/05/2024] Open
Abstract
INTRODUCTION A full understanding of the integration of the mechanisms of vascular tone regulation requires an interrogation of the temporal behavior of arterioles across vasoactive challenges. Building on previous work, the purpose of the present study was to start to interrogate the temporal nature of arteriolar tone regulation with physiological stimuli. METHODS We determined the response rate of ex vivo proximal and in situ distal resistance arterioles when challenged by one-, two-, and three-parameter combinations of five major physiological stimuli (norepinephrine, intravascular pressure, oxygen, adenosine [metabolism], and intralumenal flow). Predictive machine learning models determined which factors were most influential in controlling the rate of arteriolar responses. RESULTS Results indicate that vascular response rate is dependent on the intensity of the stimulus used and can be severely hindered by altered environments, caused by application of secondary or tertiary stimuli. Advanced analytics suggest that adrenergic influences were dominant in predicting proximal arteriolar response rate compared to metabolic influences in distal arterioles. CONCLUSION These data suggest that the vascular response rate to physiologic stimuli can be strongly influenced by the local environment. Translating how these effects impact vascular networks is imperative for understanding how the microcirculation appropriately perfuses tissue across conditions.
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Affiliation(s)
- Brayden D Halvorson
- Departments of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Aaron D Ward
- Departments of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Departments of Oncology, University of Western Ontario, London, Ontario, Canada
| | - Donna Murrell
- Departments of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Departments of Oncology, University of Western Ontario, London, Ontario, Canada
| | - James C Lacefield
- Departments of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- School of Biomedical Engineering, University of Western Ontario, London, Ontario, Canada
| | - Robert W Wiseman
- Departments of Physiology and Radiology, Michigan State University, East Lansing, Michigan, USA
| | - Daniel Goldman
- Departments of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Jefferson C Frisbee
- Departments of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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Callewaert B, Gsell W, Lox M, Backes WH, Jones EAV, Himmelreich U. Intravoxel incoherent motion as a surrogate marker of perfused vascular density in rat brain. NMR IN BIOMEDICINE 2024; 37:e5148. [PMID: 38556903 DOI: 10.1002/nbm.5148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 04/02/2024]
Abstract
Intravoxel incoherent motion (IVIM) MRI has emerged as a valuable technique for the assessment of tissue characteristics and perfusion. However, there is limited knowledge about the relationship between IVIM-derived measures and changes at the level of the vascular network. In this study, we investigated the potential use of IVIM MRI as a noninvasive tool for measuring changes in cerebral vascular density. Variations in quantitative immunohistochemical measurements of the vascular density across different regions in the rat brain (cortex, corpus callosum, hippocampus, thalamus, and hypothalamus) were related to the pseudo-diffusion coefficient D* and the flowing blood fraction f in healthy Wistar rats. We assessed whether region-wise differences in the vascular density are reflected by variations in the IVIM measurements and found a significant positive relationship with the pseudo-diffusion coefficient (p < 0.05, β = 0.24). The effect of cerebrovascular alterations, such as blood-brain barrier (BBB) disruption on the perfusion-related IVIM parameters, is not well understood. Therefore, we investigated the effect of BBB disruption on the IVIM measures in a rat model of metabolic and vascular comorbidities (ZSF1 obese rat) and assessed whether this affects the relationship between the cerebral vascular density and the noninvasive IVIM measurements. We observed increased vascular permeability without detecting any differences in diffusivity, suggesting that BBB leakage is present before changes in the tissue integrity. We observed no significant difference in the relationship between cerebral vascular density and the IVIM measurements in our model of comorbidities compared with healthy normotensive rats.
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Affiliation(s)
- Bram Callewaert
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
- Department of Imaging and Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium
| | - Willy Gsell
- Department of Imaging and Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium
| | - Marleen Lox
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
| | - Walter H Backes
- Departments of Neurology and Radiology and Nuclear Medicine, Institute for Cardiovascular Diseases (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Radiology and Nuclear Medicine, Institute for Mental Health & Neuroscience (MHeNs), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Elizabeth A V Jones
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
- Department of Cardiology, Institute for Cardiovascular Diseases (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Uwe Himmelreich
- Department of Imaging and Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium
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Taylor JL, Martin-Aragon Baudel M, Nieves-Cintron M, Navedo MF. Vascular Function and Ion Channels in Alzheimer's Disease. Microcirculation 2024:e12881. [PMID: 39190776 DOI: 10.1111/micc.12881] [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: 07/04/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024]
Abstract
This review paper explores the critical role of vascular ion channels in the regulation of cerebral artery function and examines the impact of Alzheimer's disease (AD) on these processes. Vascular ion channels are fundamental in controlling vascular tone, blood flow, and endothelial function in cerebral arteries. Dysfunction of these channels can lead to impaired cerebral autoregulation, contributing to cerebrovascular pathologies. AD, characterized by the accumulation of amyloid beta (Aβ) plaques and neurofibrillary tangles, has been increasingly linked to vascular abnormalities, including altered vascular ion channel activity. Here, we briefly review the role of vascular ion channels in cerebral blood flow control and neurovascular coupling. We then examine the vascular defects in AD, the current understanding of how AD pathology affects vascular ion channel function, and how these changes may lead to compromised cerebral blood flow and neurodegenerative processes. Finally, we provide future perspectives and conclusions. Understanding this topic is important as ion channels may be potential therapeutic targets for improving cerebrovascular health and mitigating AD progression.
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Affiliation(s)
- Jade L Taylor
- Department of Pharmacology, University of California Davis, Davis, California, USA
| | | | | | - Manuel F Navedo
- Department of Pharmacology, University of California Davis, Davis, California, USA
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Park H, Lee CH. The Impact of Pulmonary Disorders on Neurological Health (Lung-Brain Axis). Immune Netw 2024; 24:e20. [PMID: 38974208 PMCID: PMC11224666 DOI: 10.4110/in.2024.24.e20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 07/09/2024] Open
Abstract
The brain and lungs, vital organs in the body, play essential roles in maintaining overall well-being and survival. These organs interact through complex and sophisticated bi-directional pathways known as the 'lung-brain axis', facilitated by their close proximity and neural connections. Numerous studies have underscored the mediation of the lung-brain axis by inflammatory responses and hypoxia-induced damage, which are pivotal to the progression of both pulmonary and neurological diseases. This review aims to delve into how pulmonary diseases, including acute/chronic airway diseases and pulmonary conditions, can instigate neurological disorders such as stroke, Alzheimer's disease, and Parkinson's disease. Additionally, we highlight the emerging research on the lung microbiome which, drawing parallels between the gut and lungs in terms of microbiome contents, may play a significant role in modulating brain health. Ultimately, this review paves the way for exciting avenues of future research and therapeutics in addressing respiratory and neurological diseases.
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Affiliation(s)
- Hongryeol Park
- Department of Tissue Morphogenesis, Max-Planck Institute for Molecular Biomedicine, Muenster 48149, Germany
| | - Chan Hee Lee
- Department of Biomedical Science, Hallym University, Chuncheon 24252, Korea
- Program of Material Science for Medicine and Pharmaceutics, Hallym University, Chuncheon 24252, Korea
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Lénárt N, Cserép C, Császár E, Pósfai B, Dénes Á. Microglia-neuron-vascular interactions in ischemia. Glia 2024; 72:833-856. [PMID: 37964690 DOI: 10.1002/glia.24487] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023]
Abstract
Cerebral ischemia is a devastating condition that results in impaired blood flow in the brain leading to acute brain injury. As the most common form of stroke, occlusion of cerebral arteries leads to a characteristic sequence of pathophysiological changes in the brain tissue. The mechanisms involved, and comorbidities that determine outcome after an ischemic event appear to be highly heterogeneous. On their own, the processes leading to neuronal injury in the absence of sufficient blood supply to meet the metabolic demand of the cells are complex and manifest at different temporal and spatial scales. While the contribution of non-neuronal cells to stroke pathophysiology is increasingly recognized, recent data show that microglia, the main immune cells of the central nervous system parenchyma, play previously unrecognized roles in basic physiological processes beyond their inflammatory functions, which markedly change during ischemic conditions. In this review, we aim to discuss some of the known microglia-neuron-vascular interactions assumed to contribute to the acute and delayed pathologies after cerebral ischemia. Because the mechanisms of neuronal injury have been extensively discussed in several excellent previous reviews, here we focus on some recently explored pathways that may directly or indirectly shape neuronal injury through microglia-related actions. These discoveries suggest that modulating gliovascular processes in different forms of stroke and other neurological disorders might have presently unexplored therapeutic potential in combination with neuroprotective and flow restoration strategies.
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Affiliation(s)
- Nikolett Lénárt
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Csaba Cserép
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Eszter Császár
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Pósfai
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Ádám Dénes
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
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Ke X, Xia S, Yu W, Mabry S, Fu Q, Menden HL, Sampath V, Lane RH. Delta like 4 regulates cerebrovascular development and endothelial integrity via DLL4-NOTCH-CLDN5 pathway and is vulnerable to neonatal hyperoxia. J Physiol 2024; 602:2265-2285. [PMID: 38632887 DOI: 10.1113/jp285716] [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: 09/22/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
The mechanisms governing brain vascularization during development remain poorly understood. A key regulator of developmental vascularization is delta like 4 (DLL4), a Notch ligand prominently expressed in endothelial cells (EC). Exposure to hyperoxia in premature infants can disrupt the development and functions of cerebral blood vessels and lead to long-term cognitive impairment. However, its role in cerebral vascular development and the impact of postnatal hyperoxia on DLL4 expression in mouse brain EC have not been explored. We determined the DLL4 expression pattern and its downstream signalling gene expression in brain EC using Dll4+/+ and Dll4+/LacZ mice. We also performed in vitro studies using human brain microvascular endothelial cells. Finally, we determined Dll4 and Cldn5 expression in mouse brain EC exposed to postnatal hyperoxia. DLL4 is expressed in various cell types, with EC being the predominant one in immature brains. Moreover, DLL4 deficiency leads to persistent abnormalities in brain microvasculature and increased vascular permeability both in vivo and in vitro. We have identified that DLL4 insufficiency compromises endothelial integrity through the NOTCH-NICD-RBPJ-CLDN5 pathway, resulting in the downregulation of the tight junction protein claudin 5 (CLDN5). Finally, exposure to neonatal hyperoxia reduces DLL4 and CLDN5 expression in developing mouse brain EC. We reveal that DLL4 is indispensable for brain vascular development and maintaining the blood-brain barrier's function and is repressed by neonatal hyperoxia. We speculate that reduced DLL4 signalling in brain EC may contribute to the impaired brain development observed in neonates exposed to hyperoxia. KEY POINTS: The role of delta like 4 (DLL4), a Notch ligand in vascular endothelial cells, in brain vascular development and functions remains unknown. We demonstrate that DLL4 is expressed at a high level during postnatal brain development in immature brains and DLL4 insufficiency leads to abnormal cerebral vasculature and increases vascular permeability both in vivo and in vitro. We identify that DLL4 regulates endothelial integrity through NOTCH-NICD-RBPJ-CLDN5 signalling. Dll4 and Cldn5 expression are decreased in mouse brain endothelial cells exposed to postnatal hyperoxia.
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Affiliation(s)
- Xingrao Ke
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Sheng Xia
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Wei Yu
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Sherry Mabry
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Qi Fu
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Heather L Menden
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Venkatesh Sampath
- Department of Pediatrics Division of Neonatology, Children's Mercy, Kansas City, MO, USA
| | - Robert H Lane
- Department of Administration, Children Mercy Research Institute, Children's Mercy, Kansas City, MO, USA
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Whitaker AA, Aaron SE, Chertoff M, Brassard P, Buchanan J, Nguyen K, Vidoni ED, Waghmare S, Eickmeyer SM, Montgomery RN, Billinger SA. Lower dynamic cerebral autoregulation following acute bout of low-volume high-intensity interval exercise in chronic stroke compared to healthy adults. J Appl Physiol (1985) 2024; 136:707-720. [PMID: 38357728 DOI: 10.1152/japplphysiol.00635.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/23/2024] [Accepted: 02/04/2024] [Indexed: 02/16/2024] Open
Abstract
Fluctuating arterial blood pressure during high-intensity interval exercise (HIIE) may challenge dynamic cerebral autoregulation (dCA), specifically after stroke after an injury to the cerebrovasculature. We hypothesized that dCA would be attenuated at rest and during a sit-to-stand transition immediately after and 30 min after HIIE in individuals poststroke compared with age- and sex-matched control subjects (CON). HIIE switched every minute between 70% and 10% estimated maximal watts for 10 min. Mean arterial pressure (MAP) and middle cerebral artery blood velocity (MCAv) were recorded. dCA was quantified during spontaneous fluctuations in MAP and MCAv via transfer function analysis. For sit-to-stand, time delay before an increase in cerebrovascular conductance index (CVCi = MCAv/MAP), rate of regulation, and % change in MCAv and MAP were measured. Twenty-two individuals poststroke (age 60 ± 12 yr, 31 ± 16 mo) and twenty-four CON (age 60 ± 13 yr) completed the study. Very low frequency (VLF) gain (P = 0.02, η2 = 0.18) and normalized gain (P = 0.01, η2 = 0.43) had a group × time interaction, with CON improving after HIIE whereas individuals poststroke did not. Individuals poststroke had lower VLF phase (P = 0.03, η2 = 0.22) after HIIE compared with CON. We found no differences in the sit-to-stand measurement of dCA. Our study showed lower dCA during spontaneous fluctuations in MCAv and MAP following HIIE in individuals poststroke compared with CON, whereas the sit-to-stand response was maintained.NEW & NOTEWORTHY This study provides novel insights into poststroke dynamic cerebral autoregulation (dCA) following an acute bout of high-intensity interval exercise (HIIE). In people after stroke, dCA appears attenuated during spontaneous fluctuations in mean arterial pressure (MAP) and middle cerebral artery blood velocity (MCAv) following HIIE. However, the dCA response during a single sit-to-stand transition after HIIE showed no significant difference from controls. These findings suggest that HIIE may temporarily challenge dCA after exercise in individuals with stroke.
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Affiliation(s)
- Alicen A Whitaker
- Department of Physical Therapy, Rehabilitation Science, and Athletic Training, University of Kansas Medical Center, Kansas City, Kansas, United States
- Department of Physical Medicine and Rehabilitation, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Stacey E Aaron
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Mark Chertoff
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
- Research Center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec-Université Laval, Quebec City, Quebec, Canada
| | - Jake Buchanan
- Department of Physical Therapy, Rehabilitation Science, and Athletic Training, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Katherine Nguyen
- Department of Physical Therapy, Rehabilitation Science, and Athletic Training, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Eric D Vidoni
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, United States
- University of Kansas Alzheimer's Disease Research Center, Fairway, Kansas, United States
| | - Saniya Waghmare
- Department of Physical Therapy, Rehabilitation Science, and Athletic Training, University of Kansas Medical Center, Kansas City, Kansas, United States
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Sarah M Eickmeyer
- Department of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Robert N Montgomery
- Department of Biostatistics & Data Science, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Sandra A Billinger
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, United States
- University of Kansas Alzheimer's Disease Research Center, Fairway, Kansas, United States
- Department of Physical Medicine and Rehabilitation, University of Kansas Medical Center, Kansas City, Kansas, United States
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States
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Nassir A, Rosenthal G, Zadka Y, Houri S, Doron O, Barnea O. Estimating intracranial parameters using an inverse mathematical model with viscoelastic elements that closely predicts complex ICP morphologies. Comput Methods Biomech Biomed Engin 2024:1-13. [PMID: 38303646 DOI: 10.1080/10255842.2024.2308695] [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: 08/06/2023] [Accepted: 01/08/2024] [Indexed: 02/03/2024]
Abstract
The quantitative relationship between arterial blood pressure (ABP) and intracranial pressure (ICP) waveforms has not been adequately explained. We hypothesized that the ICP waveform results from interferences between propagating and reflected pressure waves occurring in the cranium following the initiating arterial waveform. To demonstrate cranial effects on interferences between waves and generation of an ICP waveform morphology, we modified our previously reported mathematical model to include viscoelastic elements that affect propagation velocity. Using patient data, we implemented an inverse model methodology to generate simulated ICP waveforms in response to given ABP waveforms. We used an open database of traumatic brain injury patients and studied 65 pairs of ICP and ABP waveforms from 13 patients (five pairs from each). Incorporating viscoelastic elements into the model resulted in model-generated ICP waveforms that very closely resembled the measured waveforms with a 16-fold increase in similarity index relative to the model with only pure elasticity elements. The mean similarity index for the pure elasticity model was 0.06 ± 0.12 SD, compared to 0.96 ± 0.28 SD for the model with viscoelastic components. The normalized root mean squared error (NRMSE) improved substantially for the model with viscoelastic elements compared to the model with pure elastic elements (NRMSE of 2.09% ± 0.62 vs. 15.2% ± 4.8, respectively). The ability of the model to generate complex ICP waveforms indicates that the model may indeed reflect intracranial dynamics. Our results suggest that the model may allow the estimation of intracranial biomechanical parameters with potential clinical significance. It represents a first step in the estimation of inaccessible intracranial parameters.
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Affiliation(s)
- Abed Nassir
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Guy Rosenthal
- Department of Neurosurgery, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Yuliya Zadka
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Saadit Houri
- Department of Neurosurgery, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Omer Doron
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Ofer Barnea
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
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Zadka Y, Rosenthal G, Doron O, Barnea O. Limitation of cerebral blood flow by increased venous outflow resistance in elevated ICP. J Appl Physiol (1985) 2024; 136:224-232. [PMID: 38059286 DOI: 10.1152/japplphysiol.00477.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/13/2023] [Accepted: 12/03/2023] [Indexed: 12/08/2023] Open
Abstract
Extensive investigation and modeling efforts have been dedicated to cerebral pressure autoregulation, which is primarily regulated by the ability of the cerebral arterioles to change their resistance and modulate cerebral blood flow (CBF). However, the mechanisms by which elevated intracranial pressure (ICP) leads to increased resistance to venous outflow have received less attention. We modified our previously described model of intracranial fluid interactions with a newly developed model of a partially collapsed blood vessel, which we termed the "flow control zone" (FCZ). We sought to determine the degree to which ICP elevation causing venous compression at the FCZ becomes the main parameter limiting CBF. The FCZ component was designed using nonlinear functions representing resistance as a function of cross-sectional area and the pressure-volume relations of the vessel wall. We used our previously described swine model of cerebral edema with graduated elevation of ICP to calculate venous outflow resistance and a newly defined parameter, the cerebral resistance index (CRI), which is the ratio between venous outflow resistance and cerebrovascular resistance. Model simulations of cerebral edema and increased ICP led to increased venous outflow resistance. There was a close similarity between model predictions of venous outflow resistance and experimental results in the swine model (cross-correlation coefficient of 0.97, a mean squared error of 0.087, and a mean absolute error of 0.15). CRI was strongly correlated to ICP in the swine model (r2 = 0.77, P = 0.00012, 95% confidence interval [0.15, 0.45]). A CRI value of 0.5 was associated with ICP values above clinically significant thresholds (24 mmHg) in the swine model and a diminished capacity of changes in arteriolar resistance to influence flow in the mathematical model. Our results demonstrate the importance of venous compression at the FCZ in determining CBF when ICP is elevated. The cerebral resistance index may provide an indication of when compression of venous outflow becomes the dominant factor in limiting CBF following brain injury.NEW & NOTEWORTHY The goal of this study was to investigate the effects of venous compression caused by elevated intracranial pressure (ICP) due to cerebral edema, validated through animal experiments. The flow control zone model highlights the impact of cerebral venous compression on cerebral blood flow (CBF) during elevated ICP. The cerebral venous outflow resistance-to-cerebrovascular resistance ratio may indicate when venous outflow compression becomes the dominant factor limiting CBF. CBF regulation descriptions should consider how arterial or venous factors may predominantly influence flow in different clinical scenarios.
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Affiliation(s)
- Yuliya Zadka
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Guy Rosenthal
- Department of Neurosurgery, Hadassah University Medical Center, Jerusalem, Israel
| | - Omer Doron
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Ofer Barnea
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
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Kueck PJ, Morris JK, Stanford JA. Current Perspectives: Obesity and Neurodegeneration - Links and Risks. Degener Neurol Neuromuscul Dis 2023; 13:111-129. [PMID: 38196559 PMCID: PMC10774290 DOI: 10.2147/dnnd.s388579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/21/2023] [Indexed: 01/11/2024] Open
Abstract
Obesity is increasing in prevalence across all age groups. Long-term obesity can lead to the development of metabolic and cardiovascular diseases through its effects on adipose, skeletal muscle, and liver tissue. Pathological mechanisms associated with obesity include immune response and inflammation as well as oxidative stress and consequent endothelial and mitochondrial dysfunction. Recent evidence links obesity to diminished brain health and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Both AD and PD are associated with insulin resistance, an underlying syndrome of obesity. Despite these links, causative mechanism(s) resulting in neurodegenerative disease remain unclear. This review discusses relationships between obesity, AD, and PD, including clinical and preclinical findings. The review then briefly explores nonpharmacological directions for intervention.
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Affiliation(s)
- Paul J Kueck
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Jill K Morris
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - John A Stanford
- University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, 66160, USA
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Dounavi ME, Mak E, Swann P, Low A, Muniz-Terrera G, McKeever A, Pope M, Williams GB, Wells K, Lawlor B, Naci L, Malhotra P, Mackay C, Koychev I, Ritchie K, Su L, Ritchie CW, O’Brien JT. Differential association of cerebral blood flow and anisocytosis in APOE ε4 carriers at midlife. J Cereb Blood Flow Metab 2023; 43:1672-1684. [PMID: 37132287 PMCID: PMC10581239 DOI: 10.1177/0271678x231173587] [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: 08/08/2022] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 05/04/2023]
Abstract
Cerebral hemodynamic alterations have been observed in apolipoprotein ε4 (APOE4) carriers at midlife, however the physiological underpinnings of this observation are poorly understood. Our goal was to investigate cerebral blood flow (CBF) and its spatial coefficient of variation (CoV) in relation to APOE4 and a measure of erythrocyte anisocytosis (red blood cell distribution width - RDW) in a middle-aged cohort. Data from 563 participants in the PREVENT-Dementia study scanned with 3 T MRI cross-sectionally were analysed. Voxel-wise and region-of-interest analyses within nine vascular regions were run to detect areas of altered perfusion. Within the vascular regions, interaction terms between APOE4 and RDW in predicting CBF were examined. Areas of hyperperfusion in APOE4 carriers were detected mainly in frontotemporal regions. The APOE4 allele differentially moderated the association between RDW and CBF, an association which was more prominent in the distal vascular territories (p - [0.01, 0.05]). The CoV was not different between the considered groups. We provide novel evidence that in midlife, RDW and CBF are differentially associated in APOE4 carriers and non-carriers. This association is consistent with a differential hemodynamic response to hematological alterations in APOE4 carriers.
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Affiliation(s)
- Maria-Eleni Dounavi
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Elijah Mak
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Peter Swann
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Audrey Low
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | | | - Anna McKeever
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Marianna Pope
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Guy B Williams
- Department of Clinical Neurosciences and Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Katie Wells
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - Brian Lawlor
- Institute of Neuroscience, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Lorina Naci
- Institute of Neuroscience, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Paresh Malhotra
- Division of Brain Science, Imperial College Healthcare NHS Trust, UK
| | - Clare Mackay
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Ivan Koychev
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Li Su
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- Department of Neuroscience, University of Sheffield, Sheffield, UK
| | - Craig W Ritchie
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - John T O’Brien
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
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12
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Peleli M, Lyngso KS, Poulsen FR, Hansen PBL, Papapetropoulos A, Stubbe J. Inhibition of cystathionine-gamma lyase dampens vasoconstriction in mouse and human intracerebral arterioles. Acta Physiol (Oxf) 2023; 239:e14021. [PMID: 37555636 DOI: 10.1111/apha.14021] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/11/2023] [Accepted: 07/04/2023] [Indexed: 08/10/2023]
Abstract
AIM In extracerebral vascular beds cystathionine-gamma lyase (CSE) activity plays a vasodilatory role but the role of this hydrogen sulfide (H2 S) producing enzyme in the intracerebral arterioles remain poorly understood. We hypothesized a similar function in the intracerebral arterioles. METHODS Intracerebral arterioles were isolated from wild type C57BL/6J mouse (9-12 months old) brains and from human brain biopsies. The function (contractility and secondary dilatation) of the intracerebral arterioles was tested ex vivo by pressure myography using a perfusion set-up. Reverse transcription polymerase chain reaction was used for detecting CSE expression. RESULTS CSE is expressed in human and mouse intracerebral arterioles. CSE inhibition with L-propargylglycine (PAG) significantly dampened the K+ -induced vasoconstriction in intracerebral arterioles of both species (% of maximum contraction: in human control: 45.4 ± 2.7 versus PAG: 27 ± 5.2 and in mouse control: 50 ± 1.5 versus PAG: 33 ± 5.2) but did not affect the secondary dilatation. This effect of PAG was significantly reversed by the H2 S donor sodium hydrosulfide (NaSH) in human (PAG + NaSH: 38.8 ± 7.2) and mouse (PAG + NaSH: 41.7 ± 3.1) arterioles, respectively. The endothelial NO synthase (eNOS) inhibitor, Nω-Nitro-l-arginine methyl ester (L-NAME), and the inhibitor of soluble guanylate cyclase (sGC), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) reversed the effect of PAG on the K+ -induced vasoconstriction in the mouse arterioles and attenuated the K+ -induced secondary dilatation significantly. CONCLUSION CSE contributes to the K+ -induced vasoconstriction via a mechanism involving H2 S, eNOS, and sGC whereas the secondary dilatation is regulated by eNOS and sGC but not by CSE.
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Affiliation(s)
- Maria Peleli
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
- Laboratory of Pharmacology, Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
- Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Kristina S Lyngso
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Frantz Rom Poulsen
- Department of Neurosurgery, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark and BRIDGE (Brain Research-Interdisciplinary Guided Excellence), Odense, Denmark
- OPEN - Odense Patient Data Explorative Network, Odense, Denmark
| | - Pernille B L Hansen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Andreas Papapetropoulos
- Laboratory of Pharmacology, Department of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
- Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Jane Stubbe
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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13
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Terrett LA, McIntyre L, Turgeon AF, English SW. Anemia and Red Blood Cell Transfusion in Aneurysmal Subarachnoid Hemorrhage. Neurocrit Care 2023; 39:91-103. [PMID: 37634181 DOI: 10.1007/s12028-023-01815-0] [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: 04/26/2023] [Accepted: 07/13/2023] [Indexed: 08/29/2023]
Abstract
Anemia is very common in aneurysmal subarachnoid hemorrhage (aSAH), with approximately half of the aSAH patient population developing moderate anemia during their hospital stay. The available evidence (both physiologic and clinical) generally supports an association of anemia with unfavorable outcomes. Although aSAH shares a number of common mechanisms of secondary insult with other forms of acute brain injury, aSAH also has specific features that make it unique: an early phase (in which early brain injury predominates) and a delayed phase (in which delayed cerebral ischemia and vasospasm predominate). The effects of both anemia and transfusion are potentially variable between these phases, which may have unique considerations and possibly different risk-benefit profiles. Data on transfusion in this population are almost exclusively limited to observational studies, which suffer from significant heterogeneity and risk of bias. Overall, the results are conflicting, with the balance of the studies suggesting that transfusion is associated with unfavorable outcomes. The transfusion targets that are well established in other critically ill populations should not be automatically applied to patients with aSAH because of the unique disease characteristics of this population and the limited representation of aSAH in the clinical trials that established these targets. There are two upcoming clinical trials evaluating transfusion in aSAH that should help clarify specific transfusion targets. Until then, it is reasonable to base transfusion decisions on the current guidelines and use an individualized approach incorporating physiologic and clinical data when available.
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Affiliation(s)
- Luke A Terrett
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Adult Critical Care, Saskatchewan Health Authority, Saskatoon, SK, Canada
| | - Lauralyn McIntyre
- Department of Medicine (Critical Care), University of Ottawa, Ottawa, ON, Canada
- Clinical Epidemiology Program (CEP), Ottawa Hospital Research Institute (OHRI), Civic Campus Room F202, 1053 Carling Avenue, Ottawa, ON, K1Y 4E9, Canada
- The Ottawa Hospital, Ottawa, ON, Canada
| | - Alexis F Turgeon
- Department of Anesthesiology and Critical Care Medicine, Université Laval, Quebec City, QC, Canada
- Population Health and Optimal Health Practices Unit, Centre hospitalier universitaire de Québec-Université Laval Research Center, Quebec City, QC, Canada
| | - Shane W English
- Department of Medicine (Critical Care), University of Ottawa, Ottawa, ON, Canada.
- Clinical Epidemiology Program (CEP), Ottawa Hospital Research Institute (OHRI), Civic Campus Room F202, 1053 Carling Avenue, Ottawa, ON, K1Y 4E9, Canada.
- The Ottawa Hospital, Ottawa, ON, Canada.
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14
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Inoue Y, Shue F, Bu G, Kanekiyo T. Pathophysiology and probable etiology of cerebral small vessel disease in vascular dementia and Alzheimer's disease. Mol Neurodegener 2023; 18:46. [PMID: 37434208 PMCID: PMC10334598 DOI: 10.1186/s13024-023-00640-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/28/2023] [Indexed: 07/13/2023] Open
Abstract
Vascular cognitive impairment and dementia (VCID) is commonly caused by vascular injuries in cerebral large and small vessels and is a key driver of age-related cognitive decline. Severe VCID includes post-stroke dementia, subcortical ischemic vascular dementia, multi-infarct dementia, and mixed dementia. While VCID is acknowledged as the second most common form of dementia after Alzheimer's disease (AD) accounting for 20% of dementia cases, VCID and AD frequently coexist. In VCID, cerebral small vessel disease (cSVD) often affects arterioles, capillaries, and venules, where arteriolosclerosis and cerebral amyloid angiopathy (CAA) are major pathologies. White matter hyperintensities, recent small subcortical infarcts, lacunes of presumed vascular origin, enlarged perivascular space, microbleeds, and brain atrophy are neuroimaging hallmarks of cSVD. The current primary approach to cSVD treatment is to control vascular risk factors such as hypertension, dyslipidemia, diabetes, and smoking. However, causal therapeutic strategies have not been established partly due to the heterogeneous pathogenesis of cSVD. In this review, we summarize the pathophysiology of cSVD and discuss the probable etiological pathways by focusing on hypoperfusion/hypoxia, blood-brain barriers (BBB) dysregulation, brain fluid drainage disturbances, and vascular inflammation to define potential diagnostic and therapeutic targets for cSVD.
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Affiliation(s)
- Yasuteru Inoue
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224 USA
| | - Francis Shue
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224 USA
| | - Guojun Bu
- SciNeuro Pharmaceuticals, Rockville, MD 20850 USA
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224 USA
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15
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Fang X, Tang C, Zhang H, Border JJ, Liu Y, Shin SM, Yu H, Roman RJ, Fan F. Longitudinal characterization of cerebral hemodynamics in the TgF344-AD rat model of Alzheimer's disease. GeroScience 2023; 45:1471-1490. [PMID: 36933144 PMCID: PMC10400494 DOI: 10.1007/s11357-023-00773-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/12/2023] [Indexed: 03/19/2023] Open
Abstract
Alzheimer's disease (AD) is a global healthcare crisis. The TgF344-AD rat is an AD model exhibiting age-dependent AD pathological hallmarks. We confirmed that AD rats developed cognitive deficits at 6 months without alteration of any other major biophysical parameters. We longitudinally characterized cerebral hemodynamics in AD rats at 3, 4, 6, and 14 months. The myogenic responses of the cerebral arteries and arterioles were impaired at 4 months of age in the AD rats. Consistent with the ex vivo results, the AD rat exhibited poor autoregulation of surface and deep cortical cerebral blood flow 2 months preceding cognitive decline. The dysfunction of cerebral hemodynamics in AD is exacerbated with age associated with reduced cerebral perfusion. Further, abolished cell contractility contributes to cerebral hemodynamics imbalance in AD. This may be attributed to enhanced ROS production, reduced mitochondrial respiration and ATP production, and disrupted actin cytoskeleton in cerebral vascular contractile cells.
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Affiliation(s)
- Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Chengyun Tang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
- Department of Physiology, Medical College of Georgia, Augusta University, 1462 Laney Walker Blvd, Augusta, GA, 30912, USA
| | - Huawei Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Jane J Border
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Seung Min Shin
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI, 53226, USA
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI, 53226, USA
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
- Department of Physiology, Medical College of Georgia, Augusta University, 1462 Laney Walker Blvd, Augusta, GA, 30912, USA.
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16
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Waigi EW, Webb RC, Moss MA, Uline MJ, McCarthy CG, Wenceslau CF. Soluble and insoluble protein aggregates, endoplasmic reticulum stress, and vascular dysfunction in Alzheimer's disease and cardiovascular diseases. GeroScience 2023; 45:1411-1438. [PMID: 36823398 PMCID: PMC10400528 DOI: 10.1007/s11357-023-00748-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 01/28/2023] [Indexed: 02/25/2023] Open
Abstract
Dementia refers to a particular group of symptoms characterized by difficulties with memory, language, problem-solving, and other thinking skills that affect a person's ability to perform everyday activities. Alzheimer's disease (AD) is the most common form of dementia, affecting about 6.2 million Americans aged 65 years and older. Likewise, cardiovascular diseases (CVDs) are a major cause of disability and premature death, impacting 126.9 million adults in the USA, a number that increases with age. Consequently, CVDs and cardiovascular risk factors are associated with an increased risk of AD and cognitive impairment. They share important age-related cardiometabolic and lifestyle risk factors, that make them among the leading causes of death. Additionally, there are several premises and hypotheses about the mechanisms underlying the association between AD and CVD. Although AD and CVD may be considered deleterious to health, the study of their combination constitutes a clinical challenge, and investigations to understand the mechanistic pathways for the cause-effect and/or shared pathology between these two disease constellations remains an active area of research. AD pathology is propagated by the amyloid β (Aβ) peptides. These peptides give rise to small, toxic, and soluble Aβ oligomers (SPOs) that are nonfibrillar, and it is their levels that show a robust correlation with the extent of cognitive impairment. This review will elucidate the interplay between the effects of accumulating SPOs in AD and CVDs, the resulting ER stress response, and their role in vascular dysfunction. We will also address the potential underlying mechanisms, including the possibility that SPOs are among the causes of vascular injury in CVD associated with cognitive decline. By revealing common mechanistic underpinnings of AD and CVD, we hope that novel experimental therapeutics can be designed to reduce the burden of these devastating diseases. Graphical abstract Alzheimer's disease (AD) pathology leads to the release of Aβ peptides, and their accumulation in the peripheral organs has varying effects on various components of the cardiovascular system including endoplasmic reticulum (ER) stress and vascular damage. Image created with BioRender.com.
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Affiliation(s)
- Emily W Waigi
- Cardiovascular Translational Research Cententer (CTRC), Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - R Clinton Webb
- Cardiovascular Translational Research Cententer (CTRC), Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
- Biomedical Engineering Program, Univeristy of South Carolina, Columbia, SC, USA
| | - Melissa A Moss
- Biomedical Engineering Program, Univeristy of South Carolina, Columbia, SC, USA
- Department of Chemical Engineering, University of South Carolina, Columbia, SC, USA
| | - Mark J Uline
- Biomedical Engineering Program, Univeristy of South Carolina, Columbia, SC, USA
- Department of Chemical Engineering, University of South Carolina, Columbia, SC, USA
| | - Cameron G McCarthy
- Cardiovascular Translational Research Cententer (CTRC), Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
- Biomedical Engineering Program, Univeristy of South Carolina, Columbia, SC, USA
| | - Camilla Ferreira Wenceslau
- Cardiovascular Translational Research Cententer (CTRC), Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA.
- Biomedical Engineering Program, Univeristy of South Carolina, Columbia, SC, USA.
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17
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Gullapalli P, Fossati N, Stamenkovic D, Haque M, Cattano D. Tale of Two Cities: narrative review of oxygen. F1000Res 2023; 12:246. [PMID: 37224313 PMCID: PMC10189297 DOI: 10.12688/f1000research.130592.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/05/2023] [Indexed: 05/26/2023] Open
Abstract
The human brain contributes 2% of the body weight yet receives 15% of cardiac output and demands a constant supply of oxygen (O 2) and nutrients to meet its metabolic needs. Cerebral autoregulation is responsible for maintaining a constant cerebral blood flow that provides the supply of oxygen and maintains the energy storage capacity. We selected oxygen administration-related studies published between 1975-2021 that included meta-analysis, original research, commentaries, editorial, and review articles. In the present narrative review, several important aspects of the oxygen effects on brain tissues and cerebral autoregulation are discussed, as well the role of exogenous O 2 administration in patients with chronic ischemic cerebrovascular disease: We aimed to revisit the utility of O 2 administration in pathophysiological situations whether or not being advantageous. Indeed, a compelling clinical and experimental body of evidence questions the utility of routine oxygen administration in acute and post-recovery brain ischemia, as evident by studies in neurophysiology imaging. While O 2 is still part of common clinical practice, it remains unclear whether its routine use is safe.
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Affiliation(s)
- Pranathi Gullapalli
- Department of Anesthesiology, McGovern Medical School UTHealth, Hosuton, USA
| | - Nicoletta Fossati
- Department of Anaesthesia, St George’s Hospital and Medical School, London, UK
| | | | - Muhammad Haque
- Department of Neurology, McGovern Medical School UTHealth, Houston, USA
| | - Davide Cattano
- Department of Anesthesiology, McGovern Medical School UTHealth, Hosuton, USA
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18
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Carlsson R, Enström A, Paul G. Molecular Regulation of the Response of Brain Pericytes to Hypoxia. Int J Mol Sci 2023; 24:5671. [PMID: 36982744 PMCID: PMC10053233 DOI: 10.3390/ijms24065671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
The brain needs sufficient oxygen in order to function normally. This is achieved by a large vascular capillary network ensuring that oxygen supply meets the changing demand of the brain tissue, especially in situations of hypoxia. Brain capillaries are formed by endothelial cells and perivascular pericytes, whereby pericytes in the brain have a particularly high 1:1 ratio to endothelial cells. Pericytes not only have a key location at the blood/brain interface, they also have multiple functions, for example, they maintain blood-brain barrier integrity, play an important role in angiogenesis and have large secretory abilities. This review is specifically focused on both the cellular and the molecular responses of brain pericytes to hypoxia. We discuss the immediate early molecular responses in pericytes, highlighting four transcription factors involved in regulating the majority of transcripts that change between hypoxic and normoxic pericytes and their potential functions. Whilst many hypoxic responses are controlled by hypoxia-inducible factors (HIF), we specifically focus on the role and functional implications of the regulator of G-protein signaling 5 (RGS5) in pericytes, a hypoxia-sensing protein that is regulated independently of HIF. Finally, we describe potential molecular targets of RGS5 in pericytes. These molecular events together contribute to the pericyte response to hypoxia, regulating survival, metabolism, inflammation and induction of angiogenesis.
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Affiliation(s)
- Robert Carlsson
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Centre and Wallenberg Centre for Molecular Medicine, Lund University, 22184 Lund, Sweden
| | - Andreas Enström
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Centre and Wallenberg Centre for Molecular Medicine, Lund University, 22184 Lund, Sweden
| | - Gesine Paul
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Centre and Wallenberg Centre for Molecular Medicine, Lund University, 22184 Lund, Sweden
- Department of Neurology, Scania University Hospital, 22185 Lund, Sweden
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19
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Fang C, Magaki SD, Kim RC, Kalaria RN, Vinters HV, Fisher M. Arteriolar neuropathology in cerebral microvascular disease. Neuropathol Appl Neurobiol 2023; 49:e12875. [PMID: 36564356 DOI: 10.1111/nan.12875] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/14/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022]
Abstract
Cerebral microvascular disease (MVD) is an important cause of vascular cognitive impairment. MVD is heterogeneous in aetiology, ranging from universal ageing to the sporadic (hypertension, sporadic cerebral amyloid angiopathy [CAA] and chronic kidney disease) and the genetic (e.g., familial CAA, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy [CADASIL] and cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy [CARASIL]). The brain parenchymal consequences of MVD predominantly consist of lacunar infarcts (lacunes), microinfarcts, white matter disease of ageing and microhaemorrhages. MVD is characterised by substantial arteriolar neuropathology involving ubiquitous vascular smooth muscle cell (SMC) abnormalities. Cerebral MVD is characterised by a wide variety of arteriolar injuries but only a limited number of parenchymal manifestations. We reason that the cerebral arteriole plays a dominant role in the pathogenesis of each type of MVD. Perturbations in signalling and function (i.e., changes in proliferation, apoptosis, phenotypic switch and migration of SMC) are prominent in the pathogenesis of cerebral MVD, making 'cerebral angiomyopathy' an appropriate term to describe the spectrum of pathologic abnormalities. The evidence suggests that the cerebral arteriole acts as both source and mediator of parenchymal injury in MVD.
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Affiliation(s)
- Chuo Fang
- Department of Neurology, University of California, Irvine Medical Center, 101 The City Drive South Shanbrom Hall (Building 55), Room 121, Orange, 92868, California, USA
| | - Shino D Magaki
- Department of Pathology & Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Ronald C Kim
- Department of Pathology & Laboratory Medicine, University of California, Irvine, Orange, California, USA
| | - Raj N Kalaria
- Translational and Clinical Research Institute, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Harry V Vinters
- Department of Pathology & Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.,Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Mark Fisher
- Department of Neurology, University of California, Irvine Medical Center, 101 The City Drive South Shanbrom Hall (Building 55), Room 121, Orange, 92868, California, USA.,Department of Pathology & Laboratory Medicine, University of California, Irvine, Orange, California, USA
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20
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Deery HA, Di Paolo R, Moran C, Egan GF, Jamadar SD. The older adult brain is less modular, more integrated, and less efficient at rest: A systematic review of large-scale resting-state functional brain networks in aging. Psychophysiology 2023; 60:e14159. [PMID: 36106762 PMCID: PMC10909558 DOI: 10.1111/psyp.14159] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 12/23/2022]
Abstract
The literature on large-scale resting-state functional brain networks across the adult lifespan was systematically reviewed. Studies published between 1986 and July 2021 were retrieved from PubMed. After reviewing 2938 records, 144 studies were included. Results on 11 network measures were summarized and assessed for certainty of the evidence using a modified GRADE method. The evidence provides high certainty that older adults display reduced within-network and increased between-network functional connectivity. Older adults also show lower segregation, modularity, efficiency and hub function, and decreased lateralization and a posterior to anterior shift at rest. Higher-order functional networks reliably showed age differences, whereas primary sensory and motor networks showed more variable results. The inflection point for network changes is often the third or fourth decade of life. Age effects were found with moderate certainty for within- and between-network altered patterns and speed of dynamic connectivity. Research on within-subject bold variability and connectivity using glucose uptake provides low certainty of age differences but warrants further study. Taken together, these age-related changes may contribute to the cognitive decline often seen in older adults.
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Affiliation(s)
- Hamish A. Deery
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneVictoriaAustralia
- Monash Biomedical ImagingMonash UniversityMelbourneVictoriaAustralia
| | - Robert Di Paolo
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneVictoriaAustralia
- Monash Biomedical ImagingMonash UniversityMelbourneVictoriaAustralia
| | - Chris Moran
- Peninsula Clinical School, Central Clinical SchoolMonash UniversityFrankstonVictoriaAustralia
- Department of Geriatric MedicinePeninsula HealthFrankstonVictoriaAustralia
| | - Gary F. Egan
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneVictoriaAustralia
- Monash Biomedical ImagingMonash UniversityMelbourneVictoriaAustralia
- Australian Research Council Centre of Excellence for Integrative Brain FunctionMelbourneVictoriaAustralia
| | - Sharna D. Jamadar
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneVictoriaAustralia
- Monash Biomedical ImagingMonash UniversityMelbourneVictoriaAustralia
- Australian Research Council Centre of Excellence for Integrative Brain FunctionMelbourneVictoriaAustralia
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21
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Moir ME, Klassen SA, Zamir M, Hamner JW, Tan CO, Shoemaker JK. Regulation of cerebrovascular compliance compared with forearm vascular compliance in humans: a pharmacological study. Am J Physiol Heart Circ Physiol 2023; 324:H100-H108. [PMID: 36459447 PMCID: PMC9799136 DOI: 10.1152/ajpheart.00377.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Increasing evidence indicates that cerebrovascular compliance contributes to the dynamic regulation of cerebral blood flow but the mechanisms regulating cerebrovascular compliance in humans are unknown. This retrospective study investigated the impact of neural, endothelial, and myogenic mechanisms on the regulation of vascular compliance in the cerebral vascular bed compared with the forearm vascular bed. An index of vascular compliance (Ci) was assessed using a Windkessel model applied to blood pressure waveforms (finger photoplethysmography) and corresponding middle cerebral artery blood velocity or brachial artery blood velocity waveforms (Doppler ultrasound). Data were analyzed during a 5-min baseline period (10 waveforms) under control conditions and during distinct sympathetic blockade (experiment 1, phentolamine; 10 adults), cholinergic blockade (experiment 2, glycopyrrolate; 9 adults), and myogenic blockade (experiment 3, nicardipine; 14 adults). In experiment 1, phentolamine increased Ci similarly in the cerebral vascular bed (131 ± 135%) and forearm vascular bed (93 ± 75%; P = 0.45). In experiment 2, glycopyrrolate increased cerebrovascular Ci (72 ± 61%) and forearm vascular Ci (74 ± 64%) to a similar extent (P = 0.88). In experiment 3, nicardipine increased Ci but to a greater extent in the cerebral vascular bed (88 ± 88%) than forearm vascular bed (20 ± 45%; P = 0.01). Therefore, adrenergic, cholinergic, and myogenic mechanisms contribute to the regulation of cerebrovascular and forearm vascular compliance. However, myogenic mechanisms appear to exert more specific control over vascular compliance in the brain relative to the forearm.NEW & NOTEWORTHY Vascular compliance represents an important determinant in the dynamics and regulation of blood flow through a vascular bed. However, the mechanisms that regulate vascular compliance remain poorly understood. This study examined the impact of neural, endothelial, and myogenic mechanisms on cerebrovascular compliance compared with forearm vascular compliance. Distinct pharmacological blockade of α-adrenergic, endothelial muscarinic, and myogenic inputs altered cerebrovascular and forearm vascular compliance. These results further our understanding of vascular control and blood flow regulation in the brain.
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Affiliation(s)
- M. Erin Moir
- 1School of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - Stephen A. Klassen
- 2Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Mair Zamir
- 3Department of Mathematics, University of Western Ontario, London, Ontario, Canada,4Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - J. W. Hamner
- 5Cerebrovascular Research Laboratory, Spaulding Hospital Cambridge, Cambridge, Massachusetts
| | - Can Ozan Tan
- 6RAM, Electrical Engineering, Mathematics, and Computer Science,
University of Twente, Enschede, The Netherlands
| | - J. Kevin Shoemaker
- 1School of Kinesiology, University of Western Ontario, London, Ontario, Canada,7Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
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22
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Wang S, Tang C, Liu Y, Border JJ, Roman RJ, Fan F. Impact of impaired cerebral blood flow autoregulation on cognitive impairment. FRONTIERS IN AGING 2022; 3:1077302. [PMID: 36531742 PMCID: PMC9755178 DOI: 10.3389/fragi.2022.1077302] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 11/23/2022] [Indexed: 11/16/2023]
Abstract
Although the causes of cognitive impairment are multifactorial, emerging evidence indicates that cerebrovascular dysfunction plays an essential role in dementia. One of the most critical aspects of cerebrovascular dysfunction is autoregulation of cerebral blood flow (CBF), mainly mediated by the myogenic response, which is often impaired in dementia individuals with comorbidities, such as diabetes and hypertension. However, many unsolved questions remain. How do cerebrovascular networks coordinately modulate CBF autoregulation in health and disease? Does poor CBF autoregulation have an impact on cognitive impairment, and what are the underlying mechanisms? This review summarizes the cerebral vascular structure and myogenic (a three-phase model), metabolic (O2, CO2, adenosine, and H+), and endothelial (shear stress) factors in the regulation of CBF; and the consequences of CBF dysautoregulation. Other factors contributing to cerebrovascular dysfunction, such as impaired functional hyperemia and capillary abnormalities, are included as well. Moreover, this review highlights recent studies from our lab in terms of novel mechanisms involved in CBF autoregulation and addresses a hypothesis that there is a three-line of defense for CBF autoregulation in the cerebral vasculature.
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Affiliation(s)
- Shaoxun Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Chengyun Tang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Jane J Border
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
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Murrant CL, Fletcher NM. Capillary communication: the role of capillaries in sensing the tissue environment, coordinating the microvascular, and controlling blood flow. Am J Physiol Heart Circ Physiol 2022; 323:H1019-H1036. [PMID: 36149771 DOI: 10.1152/ajpheart.00088.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Historically, capillaries have been viewed as the microvascular site for flux of nutrients to cells and removal of waste products. Capillaries are the most numerous blood vessel segment within the tissue, whose vascular wall consists of only a single layer of endothelial cells and are situated within microns of each cell of the tissue, all of which optimizes capillaries for the exchange of nutrients between the blood compartment and the interstitial space of tissues. There is, however, a growing body of evidence to support that capillaries play an important role in sensing the tissue environment, coordinating microvascular network responses, and controlling blood flow. Much of our growing understanding of capillaries stems from work in skeletal muscle and more recent work in the brain, where capillaries can be stimulated by products released from cells of the tissue during increased activity and are able to communicate with upstream and downstream vascular segments, enabling capillaries to sense the activity levels of the tissue and send signals to the microvascular network to coordinate the blood flow response. This review will focus on the emerging role that capillaries play in communication between cells of the tissue and the vascular network required to direct blood flow to active cells in skeletal muscle and the brain. We will also highlight the emerging central role that disruptions in capillary communication may play in blood flow dysregulation, pathophysiology, and disease.
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Affiliation(s)
- Coral L Murrant
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Nicole M Fletcher
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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O'Herron PJ, Hartmann DA, Xie K, Kara P, Shih AY. 3D optogenetic control of arteriole diameter in vivo. eLife 2022; 11:e72802. [PMID: 36107146 PMCID: PMC9481242 DOI: 10.7554/elife.72802] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 08/06/2022] [Indexed: 11/23/2022] Open
Abstract
Modulation of brain arteriole diameter is critical for maintaining cerebral blood pressure and controlling regional hyperemia during neural activity. However, studies of hemodynamic function in health and disease have lacked a method to control arteriole diameter independently with high spatiotemporal resolution. Here, we describe an all-optical approach to manipulate and monitor brain arteriole contractility in mice in three dimensions using combined in vivo two-photon optogenetics and imaging. The expression of the red-shifted excitatory opsin, ReaChR, in vascular smooth muscle cells enabled rapid and repeated vasoconstriction controlled by brief light pulses. Two-photon activation of ReaChR using a spatial light modulator produced highly localized constrictions when targeted to individual arterioles within the neocortex. We demonstrate the utility of this method for examining arteriole contractile dynamics and creating transient focal blood flow reductions. Additionally, we show that optogenetic constriction can be used to reshape vasodilatory responses to sensory stimulation, providing a valuable tool to dissociate blood flow changes from neural activity.
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Affiliation(s)
- Philip J O'Herron
- Department of Physiology, Augusta UniversityAugustaUnited States
- Department of Neuroscience, Medical University of South CarolinaCharlestonUnited States
| | - David A Hartmann
- Department of Neuroscience, Medical University of South CarolinaCharlestonUnited States
- Department of Neurology & Neurological Sciences, Stanford UniversityStanfordUnited States
| | - Kun Xie
- Department of Physiology, Augusta UniversityAugustaUnited States
| | - Prakash Kara
- Department of Neuroscience, Medical University of South CarolinaCharlestonUnited States
- Department of Neuroscience, University of MinnesotaMinneapolisUnited States
- Center for Magnetic Resonance Research, University of MinnesotaMinneapolisUnited States
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South CarolinaCharlestonUnited States
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research InstituteSeattleUnited States
- Department of Bioengineering, University of WashingtonSeattleUnited States
- Department of Pediatrics, University of WashingtonSeattleUnited States
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Lansdell TA, Chambers LC, Dorrance AM. Endothelial Cells and the Cerebral Circulation. Compr Physiol 2022; 12:3449-3508. [PMID: 35766836 DOI: 10.1002/cphy.c210015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.
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Affiliation(s)
- Theresa A Lansdell
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
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Kowalsky JM. Predicting COVID-19 and seasonal influenza vaccine uptake: The impact of fear and vasovagal symptoms. Appl Psychol Health Well Being 2022; 15:293-314. [PMID: 35705510 PMCID: PMC9349497 DOI: 10.1111/aphw.12380] [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: 12/29/2021] [Accepted: 05/29/2022] [Indexed: 11/29/2022]
Abstract
Vaccines are vital to protecting health. However, fear and experiencing vasovagal symptoms (e.g., dizziness) are deterrents to medical procedures. Thus, study aims were to test (1) if vaccine relevant fears predict vasovagal symptoms during or following seasonal influenza vaccination and (2) if vaccine relevant fears and vasovagal symptoms predict seasonal influenza and COVID-19 vaccine uptake. Using a prospective design, 1077 participants recruited online completed surveys during Oct 2019 assessing vaccine relevant fears, and May-June 2020 assessing 2019-2020 seasonal influenza vaccine uptake, ratings of vasovagal symptoms, and seasonal influenza and COVID-19 vaccination intention. A behavioral follow up assessing 2020-2021 seasonal influenza and COVID-19 vaccine uptake took place June-July 2021. Heightened vaccine relevant fears predicted reduced 2019-2020 seasonal influenza vaccine uptake and greater vasovagal symptoms among those who did receive a seasonal influenza vaccine. Serial mediation analyses identified significant indirect effects with greater vaccine relevant fears reducing 2020-2021 seasonal influenza vaccine uptake through intention and reducing COVID-19 vaccine uptake through vasovagal symptoms and intention. Intervention research to reduce fear and prevent vasovagal symptoms to support vaccine uptake is warranted.
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Pritchard AB, Fabian Z, Lawrence CL, Morton G, Crean S, Alder JE. An Investigation into the Effects of Outer Membrane Vesicles and Lipopolysaccharide of Porphyromonas gingivalis on Blood-Brain Barrier Integrity, Permeability, and Disruption of Scaffolding Proteins in a Human in vitro Model. J Alzheimers Dis 2022; 86:343-364. [PMID: 35034897 DOI: 10.3233/jad-215054] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The effects of the key pathogens and virulence factors associated with gum disease such as Porphyromonas gingivalis (P. gingivalis) on the central nervous system is of great interest with respect to development of neuropathologies and hence therapeutics and preventative strategies. Chronic infections and associated inflammation are known to weaken the first line of defense for the brain, the blood-brain barrier (BBB). OBJECTIVE The focus of this study is to utilize an established human in vitro BBB model to evaluate the effects of P. gingivalis virulence factors lipopolysaccharide (LPS) and outer membrane vesicles (OMVs) on a primary-derived human model representing the neurovascular unit of the BBB. METHODS Changes to the integrity of the BBB after application of P. gingivalis LPS and OMVs were investigated and correlated with transport of LPS. Additionally, the effect of P. gingivalis LPS and OMVs on human brain microvascular endothelial cells in monolayer was evaluated using immunofluorescence microscopy. RESULTS The integrity of the BBB model was weakened by application of P. gingivalis LPS and OMVs, as measured by a decrease in electrical resistance and a recovery deficit was seen in comparison to the controls. Application of P. gingivalis OMVs to a monoculture of human brain microvascular endothelial cells showed disruption of the tight junction zona occludens protein (ZO-1) compared to controls. CONCLUSION These findings show that the integrity of tight junctions of the human BBB could be weakened by association with P. gingivalis virulence factors LPS and OMVs containing proteolytic enzymes (gingipains).
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Affiliation(s)
- Anna Barlach Pritchard
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Zsolt Fabian
- School of Medicine, University of Central Lancashire, Preston, UK
| | - Clare L Lawrence
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - Glyn Morton
- School of Forensic and Investigative Science, University of Central Lancashire, Preston, UK
| | - StJohn Crean
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
| | - Jane E Alder
- Brain and Behaviour Centre, Faculty of Clinical and Biomedical Sciences, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
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28
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Rudge JD. A New Hypothesis for Alzheimer's Disease: The Lipid Invasion Model. J Alzheimers Dis Rep 2022; 6:129-161. [PMID: 35530118 PMCID: PMC9028744 DOI: 10.3233/adr-210299] [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: 10/01/2021] [Accepted: 02/05/2022] [Indexed: 02/07/2023] Open
Abstract
This paper proposes a new hypothesis for Alzheimer's disease (AD)-the lipid invasion model. It argues that AD results from external influx of free fatty acids (FFAs) and lipid-rich lipoproteins into the brain, following disruption of the blood-brain barrier (BBB). The lipid invasion model explains how the influx of albumin-bound FFAs via a disrupted BBB induces bioenergetic changes and oxidative stress, stimulates microglia-driven neuroinflammation, and causes anterograde amnesia. It also explains how the influx of external lipoproteins, which are much larger and more lipid-rich, especially more cholesterol-rich, than those normally present in the brain, causes endosomal-lysosomal abnormalities and overproduction of the peptide amyloid-β (Aβ). This leads to the formation of amyloid plaques and neurofibrillary tangles, the most well-known hallmarks of AD. The lipid invasion model argues that a key role of the BBB is protecting the brain from external lipid access. It shows how the BBB can be damaged by excess Aβ, as well as by most other known risk factors for AD, including aging, apolipoprotein E4 (APOE4), and lifestyle factors such as hypertension, smoking, obesity, diabetes, chronic sleep deprivation, stress, and head injury. The lipid invasion model gives a new rationale for what we already know about AD, explaining its many associated risk factors and neuropathologies, including some that are less well-accounted for in other explanations of AD. It offers new insights and suggests new ways to prevent, detect, and treat this destructive disease and potentially other neurodegenerative diseases.
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Affiliation(s)
- Jonathan D’Arcy Rudge
- School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom
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29
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Simpson DM, Payne SJ, Panerai RB. The INfoMATAS project: Methods for assessing cerebral autoregulation in stroke. J Cereb Blood Flow Metab 2022; 42:411-429. [PMID: 34279146 PMCID: PMC8851676 DOI: 10.1177/0271678x211029049] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Cerebral autoregulation refers to the physiological mechanism that aims to maintain blood flow to the brain approximately constant when blood pressure changes. Impairment of this protective mechanism has been linked to a number of serious clinical conditions, including carotid stenosis, head trauma, subarachnoid haemorrhage and stroke. While the concept and experimental evidence is well established, methods for the assessment of autoregulation in individual patients remains an open challenge, with no gold-standard having emerged. In the current review paper, we will outline some of the basic concepts of autoregulation, as a foundation for experimental protocols and signal analysis methods used to extract indexes of cerebral autoregulation. Measurement methods for blood flow and pressure are discussed, followed by an outline of signal pre-processing steps. An outline of the data analysis methods is then provided, linking the different approaches through their underlying principles and rationale. The methods cover correlation based approaches (e.g. Mx) through Transfer Function Analysis to non-linear, multivariate and time-variant approaches. Challenges in choosing which method may be 'best' and some directions for ongoing and future research conclude this work.
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Affiliation(s)
- David M Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Stephen J Payne
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, Leicester Royal Infirmary, Leicester, UK
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Wang S, Jiao F, Border JJ, Fang X, Crumpler RF, Liu Y, Zhang H, Jefferson J, Guo Y, Elliott PS, Thomas KN, Strong LB, Urvina AH, Zheng B, Rijal A, Smith SV, Yu H, Roman RJ, Fan F. Luseogliflozin, a sodium-glucose cotransporter-2 inhibitor, reverses cerebrovascular dysfunction and cognitive impairments in 18-mo-old diabetic animals. Am J Physiol Heart Circ Physiol 2022; 322:H246-H259. [PMID: 34951541 PMCID: PMC8759958 DOI: 10.1152/ajpheart.00438.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/29/2021] [Accepted: 12/15/2021] [Indexed: 02/03/2023]
Abstract
Diabetes mellitus (DM) is a leading risk factor for age-related dementia, but the mechanisms involved are not well understood. We previously discovered that hyperglycemia induced impaired myogenic response (MR) and cerebral blood flow (CBF) autoregulation in 18-mo-old DM rats associated with blood-brain barrier (BBB) leakage, impaired neurovascular coupling, and cognitive impairment. In the present study, we examined whether reducing plasma glucose with a sodium-glucose cotransporter-2 inhibitor (SGLT2i) luseogliflozin can ameliorate cerebral vascular and cognitive function in diabetic rats. Plasma glucose and HbA1c levels of 18-mo-old DM rats were reduced, and blood pressure was not altered after treatment with luseogliflozin. SGLT2i treatment restored the impaired MR of middle cerebral arteries (MCAs) and parenchymal arterioles and surface and deep cortical CBF autoregulation in DM rats. Luseogliflozin treatment also rescued neurovascular uncoupling, reduced BBB leakage and cognitive deficits in DM rats. However, SGLT2i did not have direct constrictive effects on vascular smooth muscle cells and MCAs isolated from normal rats, although it decreased reactive oxygen species production in cerebral vessels of DM rats. These results provide evidence that normalization of hyperglycemia with an SGLT2i can reverse cerebrovascular dysfunction and cognitive impairments in rats with long-standing hyperglycemia, possibly by ameliorating oxidative stress-caused vascular damage.NEW & NOTEWORTHY This study demonstrates that luseogliflozin, a sodium-glucose cotransporter-2 inhibitor, improved CBF autoregulation in association with reduced vascular oxidative stress and AGEs production in the cerebrovasculature of 18-mo-old DM rats. SGLT2i also prevented BBB leakage, impaired functional hyperemia, neurodegeneration, and cognitive impairment seen in DM rats. Luseogliflozin did not have direct constrictive effects on VSMCs and MCAs isolated from normal rats. These results provide evidence that normalization of hyperglycemia with an SGLT2i can reverse cerebrovascular dysfunction and cognitive impairments in rats with long-standing hyperglycemia, possibly by ameliorating oxidative stress-caused vascular damage.
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Affiliation(s)
- Shaoxun Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Feng Jiao
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Jane J Border
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Reece F Crumpler
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Huawei Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Joshua Jefferson
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Ya Guo
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Parker S Elliott
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Kirby N Thomas
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Luke B Strong
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Austin H Urvina
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Baoying Zheng
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Arjun Rijal
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Stanley V Smith
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
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Premužić V, Gardijan D, Herega T, Perkov D, Jelaković B. High prevalence of middle cerebral artery calcification is associated with cardiovascular mortality in hemodialyzed patients: an overlooked part of arterial tree? Int Urol Nephrol 2022; 54:1995-2004. [PMID: 35031973 DOI: 10.1007/s11255-021-03092-2] [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: 07/05/2021] [Accepted: 12/08/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE We have analyzed markers of accelerated atherosclerosis like large artery stiffness, ankle-brachial index, carotid and vertebral duplex ultrasonography and their possible associations with the incidence of intracranial calcifications, clinical course of hemodialyzed patients, and cardiovascular mortality. METHODS A computed tomographic scan of the head was performed for any neurological indication on 100 hemodialyzed patients. Eleven intracranial arteries were analyzed for calcification score, while internal carotid arteries and vertebral arteries were excluded in cerebral artery calcification score. As a control group for assessing intracranial calcifications, we have analyzed computed tomographic scans from diabetic patients who had an acute stroke. RESULTS Deceased patients had significantly higher values of augmentation index and pulse wave velocity, lower ankle-brachial index, and higher internal carotid arteries peak systolic value than survived patients. Deceased patients had significantly higher number of calcified middle cerebral arteries as well as significantly higher intracranial artery calcification score and cerebral artery calcification score. Hemodialyzed patients had significantly higher both intracranial and cerebral artery calcification scores than diabetic control group. Age and calcified middle cerebral arteries had increased HR of 1.08 and 1.36 for cardiovascular mortality. CONCLUSION This study showed that large artery stiffness and not the presence of peripheral arterial disease or carotid artery stenosis have the prognostic role of middle cerebral arteries' calcifications and cardiovascular mortality in hemodialyzed patients. The presence of middle cerebral arteries' calcifications diagnosed by a non-invasive method should be considered a marker of middle-sized conduit arteries atherosclerosis, subclinical brain damage, and future fatal cardiovascular events.
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Affiliation(s)
- Vedran Premužić
- Department of Nephrology, Hypertension, Dialysis and Transplantation, School of Medicine, University Hospital Center Zagreb, 10000, Zagreb, Croatia.
| | - Danilo Gardijan
- Department of Radiology, School of Medicine, University Hospital Center Zagreb, Zagreb, Croatia
| | - Tomislav Herega
- Department of Radiology, School of Medicine, University Hospital Center Zagreb, Zagreb, Croatia
| | - Dražen Perkov
- Department of Radiology, School of Medicine, University Hospital Center Zagreb, Zagreb, Croatia
| | - Bojan Jelaković
- Department of Nephrology, Hypertension, Dialysis and Transplantation, School of Medicine, University Hospital Center Zagreb, 10000, Zagreb, Croatia
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Menyhárt Á, Varga DP, M Tóth O, Makra P, Bari F, Farkas E. Transient Hypoperfusion to Ischemic/Anoxic Spreading Depolarization is Related to Autoregulatory Failure in the Rat Cerebral Cortex. Neurocrit Care 2021; 37:112-122. [PMID: 34855119 PMCID: PMC9259535 DOI: 10.1007/s12028-021-01393-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 11/01/2021] [Indexed: 11/27/2022]
Abstract
Background In ischemic stroke, cerebral autoregulation and neurovascular coupling may become impaired. The cerebral blood flow (CBF) response to spreading depolarization (SD) is governed by neurovascular coupling. SDs recur in the ischemic penumbra and reduce neuronal viability by the insufficiency of the CBF response. Autoregulatory failure and SD may coexist in acute brain injury. Here, we set out to explore the interplay between the impairment of cerebrovascular autoregulation, SD occurrence, and the evolution of the SD-coupled CBF response. Methods Incomplete global forebrain ischemia was created by bilateral common carotid artery occlusion in isoflurane-anesthetized rats, which induced ischemic SD (iSD). A subsequent SD was initiated 20–40 min later by transient anoxia SD (aSD), achieved by the withdrawal of oxygen from the anesthetic gas mixture for 4–5 min. SD occurrence was confirmed by the recording of direct current potential together with extracellular K+ concentration by intracortical microelectrodes. Changes in local CBF were acquired with laser Doppler flowmetry. Mean arterial blood pressure (MABP) was continuously measured via a catheter inserted into the left femoral artery. CBF and MABP were used to calculate an index of cerebrovascular autoregulation (rCBFx). In a representative imaging experiment, variation in transmembrane potential was visualized with a voltage-sensitive dye in the exposed parietal cortex, and CBF maps were generated with laser speckle contrast analysis. Results Ischemia induction and anoxia onset gave rise to iSD and aSD, respectively, albeit aSD occurred at a longer latency, and was superimposed on a gradual elevation of K+ concentration. iSD and aSD were accompanied by a transient drop of CBF (down to 11.9 ± 2.9 and 7.4 ± 3.6%, iSD and aSD), but distinctive features set the hypoperfusion transients apart. During iSD, rCBFx indicated intact autoregulation (rCBFx < 0.3). In contrast, aSD was superimposed on autoregulatory failure (rCBFx > 0.3) because CBF followed the decreasing MABP. CBF dropped 15–20 s after iSD, but the onset of hypoperfusion preceded aSD by almost 3 min. Taken together, the CBF response to iSD displayed typical features of spreading ischemia, whereas the transient CBF reduction with aSD appeared to be a passive decrease of CBF following the anoxia-related hypotension, leading to aSD. Conclusions We propose that the dysfunction of cerebrovascular autoregulation that occurs simultaneously with hypotension transients poses a substantial risk of SD occurrence and is not a consequence of SD. Under such circumstances, the evolving SD is not accompanied by any recognizable CBF response, which indicates a severely damaged neurovascular coupling.
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Affiliation(s)
- Ákos Menyhárt
- Department of Medical Physics and Informatics, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
- Cerebral Blood Flow and Metabolism Research Group, Hungarian Centre of Excellence for Molecular Medicine, University of Szeged, Szeged, Hungary
- Department of Cell Biology and Molecular Medicine, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Dániel Péter Varga
- Department of Medical Physics and Informatics, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
- Institute for Stroke and Dementia Research, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Orsolya M Tóth
- Department of Medical Physics and Informatics, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Péter Makra
- Department of Medical Physics and Informatics, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Eszter Farkas
- Cerebral Blood Flow and Metabolism Research Group, Hungarian Centre of Excellence for Molecular Medicine, University of Szeged, Szeged, Hungary.
- Department of Cell Biology and Molecular Medicine, Faculty of Science and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary.
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Lushchak VI, Duszenko M, Gospodaryov DV, Garaschuk O. Oxidative Stress and Energy Metabolism in the Brain: Midlife as a Turning Point. Antioxidants (Basel) 2021; 10:1715. [PMID: 34829586 PMCID: PMC8614699 DOI: 10.3390/antiox10111715] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/23/2021] [Accepted: 10/25/2021] [Indexed: 01/10/2023] Open
Abstract
Neural tissue is one of the main oxygen consumers in the mammalian body, and a plentitude of metabolic as well as signaling processes within the brain is accompanied by the generation of reactive oxygen (ROS) and nitrogen (RNS) species. Besides the important signaling roles, both ROS and RNS can damage/modify the self-derived cellular components thus promoting neuroinflammation and oxidative stress. While previously, the latter processes were thought to progress linearly with age, newer data point to midlife as a critical turning point. Here, we describe (i) the main pathways leading to ROS/RNS generation within the brain, (ii) the main defense systems for their neutralization and (iii) summarize the recent literature about considerable changes in the energy/ROS homeostasis as well as activation state of the brain's immune system at midlife. Finally, we discuss the role of calorie restriction as a readily available and cost-efficient antiaging and antioxidant lifestyle intervention.
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Affiliation(s)
- Volodymyr I. Lushchak
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., 76018 Ivano-Frankivsk, Ukraine; (V.I.L.); (D.V.G.)
- Department of Medical Biochemistry, I. Horbachevsky Ternopil National Medical University, 46002 Ternopil, Ukraine
- Research and Development University, 13a Shota Rustaveli Str., 76018 Ivano-Frankivsk, Ukraine
| | - Michael Duszenko
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, 72074 Tübingen, Germany;
| | - Dmytro V. Gospodaryov
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., 76018 Ivano-Frankivsk, Ukraine; (V.I.L.); (D.V.G.)
| | - Olga Garaschuk
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, 72074 Tübingen, Germany;
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34
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Zimmerman B, Rypma B, Gratton G, Fabiani M. Age-related changes in cerebrovascular health and their effects on neural function and cognition: A comprehensive review. Psychophysiology 2021; 58:e13796. [PMID: 33728712 PMCID: PMC8244108 DOI: 10.1111/psyp.13796] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/11/2021] [Accepted: 02/08/2021] [Indexed: 12/11/2022]
Abstract
The process of aging includes changes in cellular biology that affect local interactions between cells and their environments and eventually propagate to systemic levels. In the brain, where neurons critically depend on an efficient and dynamic supply of oxygen and glucose, age-related changes in the complex interaction between the brain parenchyma and the cerebrovasculature have effects on health and functioning that negatively impact cognition and play a role in pathology. Thus, cerebrovascular health is considered one of the main mechanisms by which a healthy lifestyle, such as habitual cardiorespiratory exercise and a healthful diet, could lead to improved cognitive outcomes with aging. This review aims at detailing how the physiology of the cerebral vascular system changes with age and how these changes lead to differential trajectories of cognitive maintenance or decline. This provides a framework for generating specific mechanistic hypotheses about the efficacy of proposed interventions and lifestyle covariates that contribute to enhanced cognitive well-being. Finally, we discuss the methodological implications of age-related changes in the cerebral vasculature for human cognitive neuroscience research and propose directions for future experiments aimed at investigating age-related changes in the relationship between physiology and cognitive mechanisms.
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Affiliation(s)
- Benjamin Zimmerman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gabriele Gratton
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Monica Fabiani
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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35
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Berkman JM, Rosenthal JA, Saadi A. Carotid Physiology and Neck Restraints in Law Enforcement: Why Neurologists Need to Make Their Voices Heard. JAMA Neurol 2021; 78:267-268. [PMID: 33369628 DOI: 10.1001/jamaneurol.2020.4669] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jillian M Berkman
- Department of Neurology, Mass General Brigham, Harvard Medical School, Boston, Massachusetts
| | - Joseph A Rosenthal
- Department of Neurology, Mass General Brigham, Harvard Medical School, Boston, Massachusetts
| | - Altaf Saadi
- Department of Neurology, Mass General Brigham, Harvard Medical School, Boston, Massachusetts
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36
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Relationship Between Age and Cerebral Hemodynamic Response to Breath Holding: A Functional Near-Infrared Spectroscopy Study. Brain Topogr 2021; 34:154-166. [PMID: 33544290 DOI: 10.1007/s10548-021-00818-4] [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: 05/23/2020] [Accepted: 01/06/2021] [Indexed: 10/22/2022]
Abstract
Cerebrovascular reactivity (CVR) is routinely measured as a predictor of stroke in people with a high risk of ischemic attack. Neuroimaging techniques such as emission tomography, magnetic resonance imaging, and transcranial doppler are frequently used to measure CVR even though each technique has its limitations. Functional near-infrared spectroscopy (fNIRS), also based on the principle of neurovascular coupling, is relatively inexpensive, portable, and allows for the quantification of oxy- and deoxy-hemoglobin concentration changes at a high temporal resolution. This study examines the relationship between age and CVR using fNIRS in 45 young healthy adult participants aged 18-41 years (6 females, 26.64 ± 5.49 years) performing a simple breath holding task. Eighteen of the 45 participants were scanned again after a week to evaluate the feasibility of fNIRS in reliably measuring CVR. Results indicate (a) a negative relationship between age and hemodynamic measures of breath holding task in the sensorimotor cortex of 45 individuals and (b) widespread positive coactivation within medial sensorimotor regions and between medial sensorimotor regions with supplementary motor area and prefrontal cortex during breath holding with increasing age. The intraclass correlation coefficient (ICC) indicated only a low to fair/good reliability of the breath hold hemodynamic measures from sensorimotor and prefrontal cortices. However, the average hemodynamic response to breath holding from the two sessions were found to be temporally and spatially in correspondence. Future improvements in the sensitivity and reliability of fNIRS metrics could facilitate fNIRS-based assessment of cerebrovascular function as a potential clinical tool.
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37
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Beishon L, Clough RH, Kadicheeni M, Chithiramohan T, Panerai RB, Haunton VJ, Minhas JS, Robinson TG. Vascular and haemodynamic issues of brain ageing. Pflugers Arch 2021; 473:735-751. [PMID: 33439324 PMCID: PMC8076154 DOI: 10.1007/s00424-020-02508-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 01/17/2023]
Abstract
The population is ageing worldwide, thus increasing the burden of common age-related disorders to the individual, society and economy. Cerebrovascular diseases (stroke, dementia) contribute a significant proportion of this burden and are associated with high morbidity and mortality. Thus, understanding and promoting healthy vascular brain ageing are becoming an increasing priority for healthcare systems. In this review, we consider the effects of normal ageing on two major physiological processes responsible for vascular brain function: Cerebral autoregulation (CA) and neurovascular coupling (NVC). CA is the process by which the brain regulates cerebral blood flow (CBF) and protects against falls and surges in cerebral perfusion pressure, which risk hypoxic brain injury and pressure damage, respectively. In contrast, NVC is the process by which CBF is matched to cerebral metabolic activity, ensuring adequate local oxygenation and nutrient delivery for increased neuronal activity. Healthy ageing is associated with a number of key physiological adaptations in these processes to mitigate age-related functional and structural declines. Through multiple different paradigms assessing CA in healthy younger and older humans, generating conflicting findings, carbon dioxide studies in CA have provided the greatest understanding of intrinsic vascular anatomical factors that may mediate healthy ageing responses. In NVC, studies have found mixed results, with reduced, equivalent and increased activation of vascular responses to cognitive stimulation. In summary, vascular and haemodynamic changes occur in response to ageing and are important in distinguishing “normal” ageing from disease states and may help to develop effective therapeutic strategies to promote healthy brain ageing.
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Affiliation(s)
- Lucy Beishon
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.
| | - Rebecca H Clough
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Meeriam Kadicheeni
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Tamara Chithiramohan
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Victoria J Haunton
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Jatinder S Minhas
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
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38
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Maeda KJ, McClung DM, Showmaker KC, Warrington JP, Ryan MJ, Garrett MR, Sasser JM. Endothelial cell disruption drives increased blood-brain barrier permeability and cerebral edema in the Dahl SS/jr rat model of superimposed preeclampsia. Am J Physiol Heart Circ Physiol 2020; 320:H535-H548. [PMID: 33275518 DOI: 10.1152/ajpheart.00383.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Preeclampsia is characterized by increases in blood pressure and proteinuria in late pregnancy, and neurological symptoms can appear in the form of headaches, blurred vision, cerebral edema, and, in the most severe cases, seizures (eclampsia). The causes for these cerebral manifestations remain unknown, so the use of animal models that mimic preeclampsia is essential to understanding its pathogenesis. The Dahl salt-sensitive (Dahl SS/jr) rat model develops spontaneous preeclampsia superimposed on chronic hypertension; therefore, we hypothesized that the Dahl SS/jr rat would display cerebrovascular features similar to those seen in human preeclampsia. Furthermore, we predicted that this model would allow for the identification of mechanisms underlying these changes. The pregnant Dahl SS/jr rat displayed increased cerebral edema and blood-brain barrier disruption despite tighter control of cerebral blood flow autoregulation and vascular smooth muscle myogenic tone. Analysis of cerebral endothelial cell morphology revealed increased opening of tight junctions, basement membrane dissolution, and vesicle formation. RNAseq analysis identified that genes related to endothelial cell tight junctions and blood-brain barrier integrity were differentially expressed in cerebral vessels from pregnant Dahl SS/jr compared with healthy pregnant Sprague Dawley rats. Overall, our data reveal new insights into mechanisms involved in the cerebrovascular dysfunction of preeclampsia.NEW & NOTEWORTHY This study uses the Dahl SS/jr rat as a preclinical model of spontaneous superimposed preeclampsia to demonstrate uncoupling of cerebral vascular permeability and blood-brain barrier disruption from cerebral blood flow autoregulatory dysfunction and myogenic tone. Additionally, the data presented in this study lay the foundational framework on which future experiments assessing specific transcellular transport components such as individual transporter protein expression and components of the vesicular transport system (caveolae) can be built to help reveal a potential direct mechanistic insight into the causes of cerebrovascular complications during preeclamptic pregnancies.
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Affiliation(s)
- Kenji J Maeda
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Daniel M McClung
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi.,Department of Physiology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Kurt C Showmaker
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi.,Department of Data Science, University of Mississippi Medical Center, Jackson, Mississippi
| | - Junie P Warrington
- Department of Neurology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Michael J Ryan
- Department of Physiology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Michael R Garrett
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi.,Department of Medicine (Nephrology), University of Mississippi Medical Center, Jackson, Mississippi
| | - Jennifer M Sasser
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
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39
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Konduri PR, Marquering HA, van Bavel EE, Hoekstra A, Majoie CBLM. In-Silico Trials for Treatment of Acute Ischemic Stroke. Front Neurol 2020; 11:558125. [PMID: 33041995 PMCID: PMC7525145 DOI: 10.3389/fneur.2020.558125] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/12/2020] [Indexed: 12/17/2022] Open
Abstract
Despite improved treatment, a large portion of patients with acute ischemic stroke due to a large vessel occlusion have poor functional outcome. Further research exploring novel treatments and better patient selection has therefore been initiated. The feasibility of new treatments and optimized patient selection are commonly tested in extensive and expensive randomized clinical trials. in-silico trials, computer-based simulation of randomized clinical trials, have been proposed to aid clinical trials. In this white paper, we present our vision and approach to set up in-silico trials focusing on treatment and selection of patients with an acute ischemic stroke. The INSIST project (IN-Silico trials for treatment of acute Ischemic STroke, www.insist-h2020.eu) is a collaboration of multiple experts in computational science, cardiovascular biology, biophysics, biomedical engineering, epidemiology, radiology, and neurology. INSIST will generate virtual populations of acute ischemic stroke patients based on anonymized data from the recent stroke trials and registry, and build on the existing and emerging in-silico models for acute ischemic stroke, its treatment (thrombolysis and thrombectomy) and the resulting perfusion changes. These models will be used to design a platform for in-silico trials that will be validated with existing data and be used to provide a proof of concept of the potential efficacy of this emerging technology. The platform will be used for preliminary evaluation of the potential suitability and safety of medication, new thrombectomy device configurations and methods to select patient subpopulations for better treatment outcome. This could allow generating, exploring and refining relavant hypotheses on potential causal pathways (which may follow from the evidence obtained from clinical trials) and improving clinical trial design. Importantly, the findings of the in-silico trials will require validation under the controlled settings of randomized clinical trials.
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Affiliation(s)
- Praneeta R Konduri
- Biomedical Engineering and Physics, Amsterdam University Medical Centers, Amsterdam, Netherlands.,Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Henk A Marquering
- Biomedical Engineering and Physics, Amsterdam University Medical Centers, Amsterdam, Netherlands.,Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Ed E van Bavel
- Biomedical Engineering and Physics, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Alfons Hoekstra
- Computational Science Lab, Institute for Informatics, Faculty of Science, University of Amsterdam, Amsterdam, Netherlands
| | - Charles B L M Majoie
- Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands
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40
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Muhire G, Iulita MF, Vallerand D, Youwakim J, Gratuze M, Petry FR, Planel E, Ferland G, Girouard H. Arterial Stiffness Due to Carotid Calcification Disrupts Cerebral Blood Flow Regulation and Leads to Cognitive Deficits. J Am Heart Assoc 2020; 8:e011630. [PMID: 31057061 PMCID: PMC6512142 DOI: 10.1161/jaha.118.011630] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Arterial stiffness is associated with cognitive decline and dementia; however, the precise mechanisms by which it affects the brain remain unclear. Methods and Results Using a mouse model based on carotid calcification this study characterized mechanisms that could contribute to brain degeneration due to arterial stiffness. At 2 weeks postcalcification, carotid stiffness attenuated resting cerebral blood flow in several brain regions including the perirhinal/entorhinal cortex, hippocampus, and thalamus, determined by autoradiography (P<0.05). Carotid calcification impaired cerebral autoregulation and diminished cerebral blood flow responses to neuronal activity and to acetylcholine, examined by laser Doppler flowmetry (P<0.05, P<0.01). Carotid stiffness significantly affected spatial memory at 3 weeks (P<0.05), but not at 2 weeks, suggesting that cerebrovascular impairments precede cognitive dysfunction. In line with the endothelial deficits, carotid stiffness led to increased blood‐brain barrier permeability in the hippocampus (P<0.01). This region also exhibited reductions in vessel number containing collagen IV (P<0.01), as did the somatosensory cortex (P<0.05). No evidence of cerebral microhemorrhages was present. Carotid stiffness did not affect the production of mouse amyloid‐β (Aβ) or tau phosphorylation, although it led to a modest increase in the Aβ40/Aβ42 ratio in frontal cortex (P<0.01). Conclusions These findings suggest that carotid stiffness alters brain microcirculation and increases blood‐brain barrier permeability associated with cognitive impairments. Therefore, arterial stiffness should be considered a relevant target to protect the brain and prevent cognitive dysfunctions.
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Affiliation(s)
- Gervais Muhire
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada
| | - M Florencia Iulita
- 2 Groupe de Recherche sur le Système Nerveux Central Université de Montréal Québec Canada.,3 Département de Neurosciences Université de Montréal Québec Canada
| | - Diane Vallerand
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada
| | - Jessica Youwakim
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada
| | - Maud Gratuze
- 4 Département de Psychiatrie et Neurosciences Université Laval Québec Québec Canada
| | - Franck R Petry
- 4 Département de Psychiatrie et Neurosciences Université Laval Québec Québec Canada
| | - Emmanuel Planel
- 4 Département de Psychiatrie et Neurosciences Université Laval Québec Québec Canada.,5 Centre de Recherche du CHU de Québec Québec Canada
| | - Guylaine Ferland
- 6 Département de Nutrition Université de Montréal Québec Canada.,7 Centre de Recherche de l'Institut de Cardiologie de Montréal Montréal Québec Canada
| | - Hélène Girouard
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada.,2 Groupe de Recherche sur le Système Nerveux Central Université de Montréal Québec Canada.,8 Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal Montréal Québec Canada
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41
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Andjelkovic AV, Stamatovic SM, Phillips CM, Martinez-Revollar G, Keep RF. Modeling blood-brain barrier pathology in cerebrovascular disease in vitro: current and future paradigms. Fluids Barriers CNS 2020; 17:44. [PMID: 32677965 PMCID: PMC7367394 DOI: 10.1186/s12987-020-00202-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
The complexity of the blood-brain barrier (BBB) and neurovascular unit (NVU) was and still is a challenge to bridge. A highly selective, restrictive and dynamic barrier, formed at the interface of blood and brain, the BBB is a "gatekeeper" and guardian of brain homeostasis and it also acts as a "sensor" of pathological events in blood and brain. The majority of brain and cerebrovascular pathologies are associated with BBB dysfunction, where changes at the BBB can lead to or support disease development. Thus, an ultimate goal of BBB research is to develop competent and highly translational models to understand mechanisms of BBB/NVU pathology and enable discovery and development of therapeutic strategies to improve vascular health and for the efficient delivery of drugs. This review article focuses on the progress being made to model BBB injury in cerebrovascular diseases in vitro.
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Affiliation(s)
- Anuska V Andjelkovic
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA.
| | - Svetlana M Stamatovic
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA
| | - Chelsea M Phillips
- Graduate Program in Neuroscience, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Gabriela Martinez-Revollar
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Molecular Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
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42
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Medicherla CB, Lewis A. The critically ill brain after cardiac arrest. Ann N Y Acad Sci 2020; 1507:12-22. [PMID: 32618012 DOI: 10.1111/nyas.14423] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/27/2020] [Accepted: 06/09/2020] [Indexed: 12/11/2022]
Abstract
Cardiac arrest can cause hypoxic-anoxic ischemic brain injury due to signaling cascades that lead to damaged cell membranes and vital cellular organelles, resulting in cell death in the setting of low or no oxygen. Some brain areas are more prone to damage than others, so patients with hypoxic-anoxic ischemic brain injury present with several outcomes, including reduced level of consciousness or alertness, memory deficits, uncoordinated movements, and seizures. Some patients may have mild deficits, while others may have such severe injury that it can progress to brain death. High-quality cardiopulmonary resuscitation is a proven technique to improve outcome after cardiac arrest, although morbidity and mortality remain high. Induced hypothermia, which involves artificially cooling the body immediately after cardiac arrest, may reduce injury to the brain and improve morbidity and mortality. Neuroprognostication after cardiac arrest is challenging and requires a multimodal approach involving clinical neurologic examinations, brain imaging, electrical studies to assess brain activity, and biomarkers to predict outcome.
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Affiliation(s)
| | - Ariane Lewis
- Department of Neurology, New York University Langone Medical Center, New York, New York.,Department of Neurosurgery, New York University Langone Medical Center, New York, New York
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43
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Abi-Ghanem C, Robison LS, Zuloaga KL. Androgens' effects on cerebrovascular function in health and disease. Biol Sex Differ 2020; 11:35. [PMID: 32605602 PMCID: PMC7328272 DOI: 10.1186/s13293-020-00309-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/20/2020] [Indexed: 12/18/2022] Open
Abstract
Androgens affect the cerebral vasculature and may contribute to sex differences in cerebrovascular diseases. Men are at a greater risk for stroke and vascular contributions to cognitive impairment and dementia (VCID) compared to women throughout much of the lifespan. The cerebral vasculature is a target for direct androgen actions, as it expresses several sex steroid receptors and metabolizing enzymes. Androgens’ actions on the cerebral vasculature are complex, as they have been shown to have both protective and detrimental effects, depending on factors such as age, dose, and disease state. When administered chronically, androgens are shown to be pro-angiogenic, promote vasoconstriction, and influence blood-brain barrier permeability. In addition to these direct effects of androgens on the cerebral vasculature, androgens also influence other vascular risk factors that may contribute to sex differences in cerebrovascular diseases. In men, low androgen levels have been linked to metabolic and cardiovascular diseases including hypertension, diabetes, hyperlipidemia, and obesity, which greatly increase the risk of stroke and VCID. Thus, a better understanding of androgens’ interactions with the cerebral vasculature under physiological and pathological conditions is of key importance.
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Affiliation(s)
- Charly Abi-Ghanem
- Department of Neuroscience & Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA
| | - Lisa S Robison
- Department of Neuroscience & Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA
| | - Kristen L Zuloaga
- Department of Neuroscience & Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA.
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44
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Lee SWL, Campisi M, Osaki T, Possenti L, Mattu C, Adriani G, Kamm RD, Chiono V. Modeling Nanocarrier Transport across a 3D In Vitro Human Blood-Brain-Barrier Microvasculature. Adv Healthc Mater 2020; 9:e1901486. [PMID: 32125776 PMCID: PMC7486802 DOI: 10.1002/adhm.201901486] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 12/16/2019] [Indexed: 01/31/2023]
Abstract
Polymer nanoparticles (NPs), due to their small size and surface functionalization potential have demonstrated effective drug transport across the blood-brain-barrier (BBB). Currently, the lack of in vitro BBB models that closely recapitulate complex human brain microenvironments contributes to high failure rates of neuropharmaceutical clinical trials. In this work, a previously established microfluidic 3D in vitro human BBB model, formed by the self-assembly of human-induced pluripotent stem cell-derived endothelial cells, primary brain pericytes, and astrocytes in triculture within a 3D fibrin hydrogel is exploited to quantify polymer NP permeability, as a function of size and surface chemistry. Microvasculature are perfused with commercially available 100-400 nm fluorescent polystyrene (PS) NPs, and newly synthesized 100 nm rhodamine-labeled polyurethane (PU) NPs. Confocal images are taken at different timepoints and computationally analyzed to quantify fluorescence intensity inside/outside the microvasculature, to determine NP spatial distribution and permeability in 3D. Results show similar permeability of PS and PU NPs, which increases after surface-functionalization with brain-associated ligand holo-transferrin. Compared to conventional transwell models, the method enables rapid analysis of NP permeability in a physiologically relevant human BBB set-up. Therefore, this work demonstrates a new methodology to preclinically assess NP ability to cross the human BBB.
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Affiliation(s)
- Sharon Wei Ling Lee
- Singapore-MIT Alliance for Research and Technology (SMART), BioSystems and Micromechanics (BioSyM) IRG, 1 Create Way, #04-13/14, Singapore, 138602, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117545, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Biopolis, Singapore, 138648, Singapore
| | - Marco Campisi
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca Degli Abruzzi 24, Torino, 10129, Italy
| | - Tatsuya Osaki
- Institute of Industrial Science, The University of Tokyo, Fe412, Komaba 4-6-1, Meguro-ku, 153-8505, Japan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 500 Technology Square, MIT Building, Room NE47-321, Cambridge, MA, 02139, USA
| | - Luca Possenti
- LaBS, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta" (CMIC), Politecnico di Milano, Piazza Leonardo Da Vinci 32, Milan, 20133, Italy
| | - Clara Mattu
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca Degli Abruzzi 24, Torino, 10129, Italy
| | - Giulia Adriani
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Biopolis, Singapore, 138648, Singapore
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Roger Dale Kamm
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 500 Technology Square, MIT Building, Room NE47-321, Cambridge, MA, 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, MIT Building, Room NE47-321, Cambridge, MA, 02139, USA
| | - Valeria Chiono
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca Degli Abruzzi 24, Torino, 10129, Italy
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45
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Kim JT, Won SY, Kang K, Kim SH, Park MS, Choi KH, Nam TS, Denis SW, Ferdinandusse S, Lee JE, Choi SY, Kim MK. ACOX3 Dysfunction as a Potential Cause of Recurrent Spontaneous Vasospasm of Internal Carotid Artery. Transl Stroke Res 2020; 11:1041-1051. [PMID: 31975215 DOI: 10.1007/s12975-020-00779-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 11/24/2022]
Abstract
Recurrent spontaneous vasospasm of the extracranial internal carotid artery (RSV-eICA) is a rarely recognized cause of ischemic stroke in young adults. However, its pathophysiology remains largely unknown. Through whole-exome sequencing of the ACOX3 gene of two dizygotic Korean twin brothers affected by RSV-eICA, we identified two compound heterozygous missense variants c.235 T > G (p.F79 V) and c.665G > A (p.G222E). In silico analysis indicated that both variants were classified as pathogenic. In vitro ACOX3 enzyme assay indicated practically no enzyme activity in both F79 V and G222E mutants. To determine the effect of the mutants on vasospasm, we used a collagen contraction assay on human aortic smooth muscle cells (HASMC). Carbachol, a cholinergic agonist, induces contraction of HASMC. Knockdown of ACOX3 in HASMC, using siRNA, significantly repressed HASMC contraction triggered by carbachol. The carbachol-induced HASMC contraction was restored by transfection with plasmids encoding siRNA-resistant wild-type ACOX3, but not by transfection with ACOX3 G222E or by co-transfection with ACOX3 F79 V and ACOX3 G222E, indicating that the two ACOX3 mutants suppress carbachol-induced HASMC contraction. We propose that an ACOX3 dysfunction elicits a prolonged loss of the basal aortic myogenic tone. As a result, smooth muscles of the ICA's intermediate segment, in which the sympathetic innervation is especially rich, becomes hypersensitive to sympathomimetic stimuli (e.g., heavy exercise) leading to a recurrent vasospasm. Therefore, ACOX3 dysfunction would be a causal mechanism of RSV-eICA. For the first time, we report the possible involvement of ACOX3 in maintaining the basal myogenic tone of human arterial smooth muscle.
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Affiliation(s)
- Joon-Tae Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea
| | - So Yeon Won
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, South Korea
| | - KyungWook Kang
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea
| | - Sang-Hoon Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea
| | - Man-Seok Park
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea
| | - Kang-Ho Choi
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea
| | - Tai-Seung Nam
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea
| | - Simone W Denis
- Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Sacha Ferdinandusse
- Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam, The Netherlands
| | - Ji Eun Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, South Korea.
| | - Seok-Yong Choi
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, 61469, South Korea.
| | - Myeong-Kyu Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, 61469, South Korea.
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46
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Teixeira MI, Lopes CM, Amaral MH, Costa PC. Current insights on lipid nanocarrier-assisted drug delivery in the treatment of neurodegenerative diseases. Eur J Pharm Biopharm 2020; 149:192-217. [PMID: 31982574 DOI: 10.1016/j.ejpb.2020.01.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/16/2019] [Accepted: 01/08/2020] [Indexed: 12/12/2022]
Abstract
The central nervous system (CNS) is vulnerable to pathologic processes that lead to the development of neurodegenerative disorders like Alzheimer's, Parkinson's and Huntington's diseases, Multiple sclerosis or Amyotrophic lateral sclerosis. These are chronic and progressive pathologies characterized by the loss of neurons and the formation of misfolded proteins. Additionally, neurodegenerative diseases are accompanied by a structural and functional dysfunction of the blood-brain barrier (BBB). Although serving as a protection for the CNS, the existence of physiological barriers, especially the BBB, limits the access of several therapeutic agents to the brain, constituting a major hindrance in neurotherapeutics advancement. In this regard, nanotechnology-based approaches have arisen as a promising strategy to not only improve drug targeting to the brain, but also to increase bioavailability. Lipid nanocarriers such as liposomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), microemulsions and nanoemulsions, have already proven their potential for enhancing brain transport, crossing more easily into the CNS and allowing the administration of medicines that could benefit the treatment of neurological pathologies. Given the socioeconomic impact of such conditions and the advent of nanotechnology that inevitably leads to more effective and superior therapeutics for their management, it is imperative to constantly update on the current knowledge of these topics. Herein, we provide insight on the BBB and the pathophysiology of the main neurodegenerative disorders. Moreover, this review seeks to highlight the several approaches that can be used to improve the delivery of therapeutic agents to the CNS, while also offering an extensive overview of the latest efforts regarding the use of lipid-based nanocarriers in the management of neurodegenerative diseases.
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Affiliation(s)
- M I Teixeira
- UCIBIO, REQUIMTE, MEDTECH, Laboratory of Pharmaceutical Technology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
| | - C M Lopes
- FP-ENAS/CEBIMED, Fernando Pessoa Energy, Environment and Health Research Unit/Biomedical Research Centre, Faculty of Health Sciences, Fernando Pessoa University, Rua Carlos da Maia, 296, 4200-150 Porto, Portugal
| | - M H Amaral
- UCIBIO, REQUIMTE, MEDTECH, Laboratory of Pharmaceutical Technology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - P C Costa
- UCIBIO, REQUIMTE, MEDTECH, Laboratory of Pharmaceutical Technology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira, 228, 4050-313 Porto, Portugal
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47
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Joutel A. Prospects for Diminishing the Impact of Nonamyloid Small-Vessel Diseases of the Brain. Annu Rev Pharmacol Toxicol 2020; 60:437-456. [PMID: 31425001 DOI: 10.1146/annurev-pharmtox-010818-021712] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Small-vessel diseases (SVDs) of the brain are involved in about one-fourth of ischemic strokes and a vast majority of intracerebral hemorrhages and are responsible for nearly half of dementia cases in the elderly. SVDs are a heavy burden for society, a burden that is expected to increase further in the absence of significant therapeutic advances, given the aging population. Here, we provide a critical appraisal of currently available therapeutic approaches for nonamyloid sporadic SVDs that are largely based on targeting modifiable risk factors. We review what is known about the pathogenic mechanisms of vascular risk factor-related SVDs and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most frequent hereditary SVD, and elaborate on two mechanism-based therapeutic approaches worth exploring in sporadic SVD and CADASIL. We conclude by discussing opportunities and challenges that need to be tackled if efforts to achieve significant therapeutic advances for these diseases are to be successful.
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Affiliation(s)
- Anne Joutel
- Institute of Psychiatry and Neurosciences of Paris, INSERM UMR1266, Paris Descartes University, 75014 Paris, France; .,DHU NeuroVasc, Sorbonne Paris Cité, 75010 Paris, France.,Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont 05405, USA
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48
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Schaffenrath J, Keller A. New Insights in the Complexity and Functionality of the Neurovascular Unit. Handb Exp Pharmacol 2020; 273:33-57. [PMID: 33582883 DOI: 10.1007/164_2020_424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The neurovascular unit (NVU) encompasses all brain cells and underlines that neurons, glia and brain vasculature are in intimate physical and functional association. Brain function is dependent on blood flow and local increases in blood flow in response to neural activity - functional hyperaemia takes place at the NVU. Although this is a vital function of the NVU, many studies have demonstrated that the NVU also performs other tasks. Blood vessels in the brain, which are composed of multiple cell types, are essential for correct brain development. They constitute the niche for brain stem cells, sense the environment and communicate changes to neural tissue, and control the immune quiescence of the CNS. In this brief chapter we will discuss new insights into the biology of NVU, which have further revealed the heterogeneity and complexity of the vascular tree and its neurovascular associations.
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Affiliation(s)
- Johanna Schaffenrath
- Department of Neurosurgery, Clinical Neuroscience Center, Zurich Neuroscience Center, Zurich University Hospital, Zurich University, Zurich, Switzerland
| | - Annika Keller
- Department of Neurosurgery, Clinical Neuroscience Center, Zurich Neuroscience Center, Zurich University Hospital, Zurich University, Zurich, Switzerland.
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49
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Lyubashina OA, Mamontov OV, Volynsky MA, Zaytsev VV, Kamshilin AA. Contactless Assessment of Cerebral Autoregulation by Photoplethysmographic Imaging at Green Illumination. Front Neurosci 2019; 13:1235. [PMID: 31798408 PMCID: PMC6863769 DOI: 10.3389/fnins.2019.01235] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 10/31/2019] [Indexed: 12/15/2022] Open
Abstract
Accurate and practical assessment of the brain circulation is needed to adequately estimate the viability of cerebral blood flow regulatory mechanisms in various physiological conditions. The objective of our study was to examine feasibility of the contactless green-light imaging photoplethysmography (PPG) for assessing cerebral autoregulation by revealing the dynamic relationships between cortical microcirculation assessed by PPG and changes in systemic blood pressure caused by visceral and somatic peripheral stimuli. In anesthetized male Wistar rats, the PPG video images of the open parietal cortex (either with unimpaired or dissected dura mater), electrocardiogram, and systemic arterial blood pressure (ABP) in the femoral artery were continuously recorded before, during and after visceral (colorectal distension) or somatic (tail squeezing) stimulation. In the vast majority of experiments with intact and removed dura mater, both spontaneous and peripheral stimulation-evoked changes in ABP negatively correlated with the accompanying alterations in the amplitude of pulsatile PPG component (APC), i.e., an increase of ABP resulted in a decrease of APC and vice versa. The most pronounced ABP and APC alterations were induced by noxious stimuli. Visceral painful stimulation in all cases caused short-term hypotension with simultaneous increase in cortical APC, whereas somatic noxious stimuli in 8 of 21 trials produced hypertensive effect with decreased APC. Animals with pressure 50-70 mmHg possessed higher negative cerebrovascular response rate of ABP-APC gradients than rats with either lower or higher pressure. Severe hypotension reversed the negative ratio to positive one, which was especially evident under visceral pain stimulation. Amplitude of the pulsatile PPG component probably reflects the regulation of vascular tone of cerebral cortex in response to systemic blood pressure fluctuations. When combined with different kinds of peripheral stimuli, the technique is capable for evaluation of normal and elucidation of impaired cerebrovascular system reactivity to particular physiological events, for example pain. The reported contactless PPG monitoring of cortical circulatory dynamics during neurosurgical interventions in combination with recordings of changes in other physiological parameters, such as systemic blood pressure and ECG, has the appealing potential to monitor viability of the cortex vessels and determine the state of patient’s cerebrovascular autoregulation.
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Affiliation(s)
- Olga A Lyubashina
- Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, Russia.,Valdman Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
| | - Oleg V Mamontov
- Department of Circulation Physiology, Almazov National Medical Research Centre, Saint Petersburg, Russia.,Faculty of Applied Optics, ITMO University, Saint Petersburg, Russia
| | - Maxim A Volynsky
- Faculty of Applied Optics, ITMO University, Saint Petersburg, Russia
| | - Valeriy V Zaytsev
- Faculty of Applied Optics, ITMO University, Saint Petersburg, Russia
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50
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Grifno GN, Farrell AM, Linville RM, Arevalo D, Kim JH, Gu L, Searson PC. Tissue-engineered blood-brain barrier models via directed differentiation of human induced pluripotent stem cells. Sci Rep 2019; 9:13957. [PMID: 31562392 PMCID: PMC6764995 DOI: 10.1038/s41598-019-50193-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/09/2019] [Indexed: 02/07/2023] Open
Abstract
Three-dimensional (3D) tissue-engineered models of the blood-brain barrier (BBB) recapitulate in vivo shear stress, cylindrical geometry, and cell-ECM interactions. Here we address four issues associated with BBB models: cell source, barrier function, cryopreservation, and matrix stiffness. We reproduce a directed differentiation of brain microvascular endothelial cells (dhBMECs) from two fluorescently labeled human induced pluripotent stem cell lines (hiPSCs) and demonstrate physiological permeability of Lucifer yellow over six days. Microvessels formed from cryopreserved dhBMECs show expression of BBB markers and maintain physiological barrier function comparable to non-cryopreserved cells. Microvessels displaying physiological barrier function are formed in collagen I hydrogels with stiffness matching that of human brain. The dilation response of microvessels was linear with increasing transmural pressure and was dependent on matrix stiffness. Together these results advance capabilities for tissue-engineered BBB models.
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Affiliation(s)
- Gabrielle N Grifno
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Alanna M Farrell
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Raleigh M Linville
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Diego Arevalo
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Joo Ho Kim
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Luo Gu
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter C Searson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.
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