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Hark C, Chen J, Blöck J, Buhl EM, Radermacher H, Pola R, Pechar M, Etrych T, Peña Q, Rix A, Drude NI, Kiessling F, Lammers T, May JN. RGD-coated polymeric microbubbles promote ultrasound-mediated drug delivery in an inflamed endothelium-pericyte co-culture model of the blood-brain barrier. Drug Deliv Transl Res 2024:10.1007/s13346-024-01561-6. [PMID: 38498080 DOI: 10.1007/s13346-024-01561-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2024] [Indexed: 03/19/2024]
Abstract
Drug delivery to central nervous pathologies is compromised by the blood-brain barrier (BBB). A clinically explored strategy to promote drug delivery across the BBB is sonopermeation, which relies on the combined use of ultrasound (US) and microbubbles (MB) to induce temporally and spatially controlled opening of the BBB. We developed an advanced in vitro BBB model to study the impact of sonopermeation on the delivery of the prototypic polymeric drug carrier pHPMA as a larger molecule and the small molecule antiviral drug ribavirin. This was done under standard and under inflammatory conditions, employing both untargeted and RGD peptide-coated MB. The BBB model is based on human cerebral capillary endothelial cells and human placental pericytes, which are co-cultivated in transwell inserts and which present with proper transendothelial electrical resistance (TEER). Sonopermeation induced a significant decrease in TEER values and facilitated the trans-BBB delivery of fluorescently labeled pHPMA (Atto488-pHPMA). To study drug delivery under inflamed endothelial conditions, which are typical for e.g. tumors, neurodegenerative diseases and CNS infections, tumor necrosis factor (TNF) was employed to induce inflammation in the BBB model. RGD-coated MB bound to and permeabilized the inflamed endothelium-pericyte co-culture model, and potently improved Atto488-pHPMA and ribavirin delivery. Taken together, our work combines in vitro BBB bioengineering with MB-mediated drug delivery enhancement, thereby providing a framework for future studies on optimization of US-mediated drug delivery to the brain.
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Affiliation(s)
- Christopher Hark
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Junlin Chen
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Julia Blöck
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Eva Miriam Buhl
- Electron Microscopy Facility, Institute for Pathology, University Clinic RWTH Aachen, Aachen, Germany
| | - Harald Radermacher
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Robert Pola
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Michal Pechar
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Tomáš Etrych
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Quim Peña
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Anne Rix
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Natascha I Drude
- QUEST Center for Responsible Research, Berlin Institute of Health at Charité, Berlin, Germany
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany
| | - Twan Lammers
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany.
| | - Jan-Niklas May
- Institute for Experimental Molecular Imaging (ExMI), RWTH Aachen University, Aachen, Germany.
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Zhuang X, He G, Zeng Y, Li M, Su Y, Chen X, Zhang Y, Gan Y, Wen F, Zhang X. Quantitative evaluation of choroidal and retinal microvasculature post-alcohol consumption: A pilot study. Microvasc Res 2024; 152:104629. [PMID: 37984565 DOI: 10.1016/j.mvr.2023.104629] [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: 10/22/2023] [Revised: 11/04/2023] [Accepted: 11/14/2023] [Indexed: 11/22/2023]
Abstract
PURPOSE The aim of this study was to assess the impact of acute, heavy alcohol consumption on the ocular microvasculature, providing insight into the largely unexplored response of microvascular structures to excessive drinking. METHODS Healthy volunteers in this prospective pilot study were tasked with consuming spirits, wine, and water at different times. Alcohol intake was measured according to body weight (g/kg). The ocular microvascular parameters primarily including choroidal volume (CV) and choroidal vessel volume (CVV) reflecting arteriolovenularity, and choroidal capillary density (CCD) reflecting capillary, were evaluated using swept-source optical coherence tomography angiography at baseline and 0.5-, 1-, 2-, and 3-hour post-consumption. RESULTS A total of 34 eyes underwent 170 successful examinations in this study. After consuming spirits or wine, we observed significant decreases in CV and CVV values (all P < 0.01 for 0.5-, 1-, 2-, and 3-hour post-consumption), along with significant increase in CCD (P < 0.05 at 0.5-, 1-, 2-hour post-spirits consumption and 1-hour post-wine consumption). The most pronounced changes occurred 1-hour after spirits or wine consumption (all P < 0.001 in both univariate and multivariate model). However, post-consumption changes in the ocular microvasculature showed no significant differences between spirits and wine (P > 0.05). Additionally, no significant differences were observed in any parameters after water intake (all P > 0.05). CONCLUSIONS Excessive alcohol consumption leads to ocular arteriolovenular vasoconstriction and capillary vasodilation, most evident 1-hour post-consumption of spirits and wine. Our research provides insight into alcohol's immediate ocular microvascular effects, hinting at systemic microvascular effects.
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Affiliation(s)
- Xuenan Zhuang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China; Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Guiqin He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Yunkao Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China; Ophthalmic Center, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Miaoling Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Yongyue Su
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Xuelin Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Yining Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Yuhong Gan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China
| | - Feng Wen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China.
| | - Xiongze Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou 510060, China.
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Mester JR, Rozak MW, Dorr A, Goubran M, Sled JG, Stefanovic B. Network response of brain microvasculature to neuronal stimulation. Neuroimage 2024; 287:120512. [PMID: 38199427 DOI: 10.1016/j.neuroimage.2024.120512] [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: 09/08/2023] [Revised: 12/21/2023] [Accepted: 01/04/2024] [Indexed: 01/12/2024] Open
Abstract
Neurovascular coupling (NVC), or the adjustment of blood flow in response to local increases in neuronal activity is a hallmark of healthy brain function, and the physiological foundation for functional magnetic resonance imaging (fMRI). However, it remains only partly understood due to the high complexity of the structure and function of the cerebrovascular network. Here we set out to understand NVC at the network level, i.e. map cerebrovascular network reactivity to activation of neighbouring neurons within a 500×500×500 μm3 cortical volume (∼30 high-resolution 3-nL fMRI voxels). Using 3D two-photon fluorescence microscopy data, we quantified blood volume and flow changes in the brain vessels in response to spatially targeted optogenetic activation of cortical pyramidal neurons. We registered the vessels in a series of image stacks acquired before and after stimulations and applied a deep learning pipeline to segment the microvascular network from each time frame acquired. We then performed image analysis to extract the microvascular graphs, and graph analysis to identify the branch order of each vessel in the network, enabling the stratification of vessels by their branch order, designating branches 1-3 as precapillary arterioles and branches 4+ as capillaries. Forty-five percent of all vessels showed significant calibre changes; with 85 % of responses being dilations. The largest absolute CBV change was in the capillaries; the smallest, in the venules. Capillary CBV change was also the largest fraction of the total CBV change, but normalized to the baseline volume, arterioles and precapillary arterioles showed the biggest relative CBV change. From linescans along arteriole-venule microvascular paths, we measured red blood cell velocities and hematocrit, allowing for estimation of pressure and local resistance along these paths. While diameter changes following neuronal activation gradually declined along the paths; the pressure drops from arterioles to venules increased despite decreasing resistance: blood flow thus increased more than local resistance decreases would predict. By leveraging functional volumetric imaging and high throughput deep learning-based analysis, our study revealed distinct hemodynamic responses across the vessel types comprising the microvascular network. Our findings underscore the need for large, dense sampling of brain vessels for characterization of neurovascular coupling at the network level in health and disease.
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Affiliation(s)
- James R Mester
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Matthew W Rozak
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Adrienne Dorr
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Maged Goubran
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - John G Sled
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Bojana Stefanovic
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.
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Jeong H, Pan Y, Akhter F, Volkow ND, Zhu D, Du C. Impairment of cerebral vascular reactivity and resting blood flow in early-staged transgenic AD mice: in vivo optical imaging studies. RESEARCH SQUARE 2023:rs.3.rs-3579916. [PMID: 37987006 PMCID: PMC10659553 DOI: 10.21203/rs.3.rs-3579916/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Background Alzheimer's disease (AD) is a neurodegenerative disorder with progressive cognitive decline in aging individuals that poses a significant challenge to patients due to an incomplete understanding of its etiology and lack of effective interventions. While "the Amyloid Cascade Hypothesis," the abnormal accumulation of amyloid-β in the brain, has been the most prevalent theory for AD, mounting evidence from clinical and epidemiological studies suggest that defects in cerebral vessels and hypoperfusion appear prior to other pathological manifestations and might contribute to AD, leading to "the Vascular Hypothesis." However, assessment of structural and functional integrity of the cerebral vasculature in vivo in the brain from AD rodent models has been challenging owing to the limited spatiotemporal resolution of conventional imaging technologies. Methods We employed two in vivo imaging technologies, i.e., Dual-Wavelength Imaging (DWI) and Optical Coherence Tomography (OCT), to evaluate cerebrovascular reactivity (CVR; responsiveness of blood vessels to vasoconstriction as triggered by cocaine) in a relatively large field of view of the cortex in vivo, and 3D quantitative cerebrovascular blood flow (CBF) imaging in living transgenic AD mice at single vessel resolution. Results Our results showed significantly impaired CVR and reduced CBF in basal state in transgenic AD mice compared to non-transgenic littermates in an early stage of AD progression. Changes in total hemoglobin (Δ[HbT]) in response to vasoconstriction were significantly attenuated in AD mice, especially in arteries and tissue, and the recovery time of Δ[HbT] after vasoconstriction was shorter for AD than WT in all types of vessels and cortical tissue, thereby indicating hypoperfusion and reduced vascular flexibility. Additionally, our 3D OCT images revealed that CBF velocities in arteries were slower and that the microvascular network was severely disrupted in the brain of AD mice. Conclusions These results suggest significant vascular impairment in basal CBF and dynamic CVR in the neurovascular network in a rodent model of AD at an early stage of the disease. These cutting-edge in vivo optical imaging tools offer an innovative venue for detecting early neurovascular dysfunction in relation to AD pathology and pave the way for clinical translation of early diagnosis and elucidation of AD pathogenesis in the future.
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Affiliation(s)
- Hyomin Jeong
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Firoz Akhter
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20857, USA
| | - Donghui Zhu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
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Bolden CT, Skibber MA, Olson SD, Zamorano Rojas M, Milewicz S, Gill BS, Cox CS. Validation and characterization of a novel blood-brain barrier platform for investigating traumatic brain injury. Sci Rep 2023; 13:16150. [PMID: 37752338 PMCID: PMC10522590 DOI: 10.1038/s41598-023-43214-7] [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: 11/09/2022] [Accepted: 09/21/2023] [Indexed: 09/28/2023] Open
Abstract
The Blood-Brain Barrier (BBB) is a highly-selective physiologic barrier responsible for maintaining cerebral homeostasis. Innovative in vitro models of the BBB are needed to provide useful insights into BBB function with CNS disorders like traumatic brain injury (TBI). TBI is a multidimensional and highly complex pathophysiological condition that requires intrinsic models to elucidate its mechanisms. Current models either lack fluidic shear stress, or neglect hemodynamic parameters important in recapitulating the human in vivo BBB phenotype. To address these limitations in the field, we developed a fluid dynamic novel platform which closely mimics these parameters. To validate our platform, Matrigel-coated Transwells were seeded with brain microvascular endothelial cells, both with and without co-cultured primary human astrocytes and bone-marrow mesenchymal stem cells. In this article we characterized BBB functional properties such as TEER and paracellular permeability. Our platform demonstrated physiologic relevant decreases in TEER in response to an ischemic environment, while directly measuring barrier fluid fluctuation. These recordings were followed with recovery, implying stability of the model. We also demonstrate that our dynamic platform is responsive to inflammatory and metabolic cues with resultant permeability coefficients. These results indicate that this novel dynamic platform will be a valuable tool for evaluating the recapitulating BBB function in vitro, screening potential novel therapeutics, and establishing a relevant paradigm to evaluate the pathophysiology of TBI.
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Affiliation(s)
- Christopher T Bolden
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.
- Center for Translational Injury Research, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.
| | - Max A Skibber
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Scott D Olson
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Miriam Zamorano Rojas
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Samantha Milewicz
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Brijesh S Gill
- Department of Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Charles S Cox
- Department of Pediatric Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.
- Center for Translational Injury Research, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.
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Fesharaki NJ, Taylor A, Mosby K, Kim JH, Ress D. Global effects of aging on the hemodynamic response function in the human brain. RESEARCH SQUARE 2023:rs.3.rs-3299293. [PMID: 37720046 PMCID: PMC10503846 DOI: 10.21203/rs.3.rs-3299293/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
In functional magnetic resonance imaging, the hemodynamic response function (HRF) is a transient, stereotypical response to local changes in cerebral hemodynamics and oxygen metabolism due to briefly (< 4 s) evoked neural activity. Accordingly, the HRF is often used as an impulse response with the assumption of linearity in data analysis. In cognitive aging studies, it has been very common to interpret differences in brain activation as age-related changes in neural activity. Contrary to this assumption, however, evidence has accrued that normal aging may also significantly affect the vasculature, thereby affecting cerebral hemodynamics and metabolism, confounding interpretation of fMRI aging studies. In this study, use was made of a multisensory stimulus to evoke the HRF in ~ 87% of cerebral cortex in cognitively intact adults with ages ranging from 22-75 years. The stimulus evokes both positive and negative HRFs, which were characterized using model-free parameters in native-space coordinates. Results showed significant age trends in HRF parameter distributions in terms of both amplitudes (e.g., peak amplitude and CNR) and temporal dynamics (e.g., full-width-at-half-maximum). This work sets the stage for using HRF methods as a biomarker for age-related pathology.
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Mühlenpfordt M, Olsen EB, Kotopoulis S, Torp SH, Snipstad S, Davies CDL, Olsman M. Real-Time Intravital Imaging of Acoustic Cluster Therapy-Induced Vascular Effects in the Murine Brain. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1212-1226. [PMID: 36858913 DOI: 10.1016/j.ultrasmedbio.2023.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 12/18/2022] [Accepted: 01/09/2023] [Indexed: 05/11/2023]
Abstract
OBJECTIVE The blood-brain barrier (BBB) is an obstacle for cerebral drug delivery. Controlled permeabilization of the barrier by external stimuli can facilitate the delivery of drugs to the brain. Acoustic Cluster Therapy (ACT®) is a promising strategy for transiently and locally increasing the permeability of the BBB to macromolecules and nanoparticles. However, the mechanism underlying the induced permeability change and subsequent enhanced accumulation of co-injected molecules requires further elucidation. METHODS In this study, the behavior of ACT® bubbles in microcapillaries in the murine brain was observed using real-time intravital multiphoton microscopy. For this purpose, cranial windows aligned with a ring transducer centered around an objective were mounted to the skull of mice. Dextrans labeled with 2 MDa fluorescein isothiocyanate (FITC) were injected to delineate the blood vessels and to visualize extravasation. DISCUSSION Activated ACT® bubbles were observed to alter the blood flow, inducing transient and local increases in the fluorescence intensity of 2 MDa FITC-dextran and subsequent extravasation in the form of vascular outpouchings. The observations indicate that ACT® induced a transient vascular leakage without causing substantial damage to the vessels in the brain. CONCLUSION The study gave novel insights into the mechanism underlying ACT®-induced enhanced BBB permeability which will be important considering treatment optimization for a safe and efficient clinical translation of ACT®.
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Affiliation(s)
- Melina Mühlenpfordt
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway; Exact Therapeutics AS, Oslo, Norway.
| | - Emma Bøe Olsen
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Spiros Kotopoulis
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sverre H Torp
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Department of Pathology, St. Olav's Hospital, Trondheim University Hospital Trondheim, Norway
| | - Sofie Snipstad
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway; Cancer Clinic, St. Olav's Hospital, Trondheim, Norway
| | | | - Marieke Olsman
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
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Mughal A, Nelson MT, Hill-Eubanks D. The post-arteriole transitional zone: a specialized capillary region that regulates blood flow within the CNS microvasculature. J Physiol 2023; 601:889-901. [PMID: 36751860 PMCID: PMC9992301 DOI: 10.1113/jp282246] [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: 08/19/2022] [Accepted: 01/13/2023] [Indexed: 02/09/2023] Open
Abstract
The brain is an energy hog, consuming available energy supplies at a rate out of all proportion to its relatively small size. This outsized demand, largely reflecting the unique computational activity of the brain, is met by an ensemble of neurovascular coupling mechanisms that link neuronal activity with local increases in blood delivery. This just-in-time replenishment strategy, made necessary by the limited energy-storage capacity of neurons, complicates the nutrient-delivery task of the cerebral vasculature, layering on a temporo-spatial requirement that invites - and challenges - mechanistic interpretation. The centre of gravity of research efforts to disentangle these mechanisms has shifted from an initial emphasis on astrocyte-arteriole-level processes to mechanisms that operate on the capillary level, a shift that has brought into sharp focus questions regarding the fine control of blood distribution to active neurons. As these investigations have drilled down into finer reaches of the microvasculature, they have revealed an arteriole-proximate subregion of CNS capillary networks that serves a regulatory function in directing blood flow into and within downstream capillaries. They have also illuminated differences in researchers' perspectives on the vascular structures and identity of mural cells in this region that impart the vasomodulatory effects that control blood distribution. In this review, we highlight the regulatory role of a variably named region of the microvasculature, referred to here as the post-arteriole transition zone, in channeling blood flow within CNS capillary networks, and underscore the contribution of dynamically contractile perivascular mural cell - generally, but not universally, recognized as pericytes - to this function.
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Affiliation(s)
- Amreen Mughal
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Mark T. Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
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McCall JR, Santibanez F, Belgharbi H, Pinton GF, Dayton PA. Non-invasive transcranial volumetric ultrasound localization microscopy of the rat brain with continuous, high volume-rate acquisition. Theranostics 2023; 13:1235-1246. [PMID: 36923540 PMCID: PMC10008741 DOI: 10.7150/thno.79189] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/24/2022] [Indexed: 02/15/2023] Open
Abstract
Rationale: Structure and function of the microvasculature provides critical information about disease state, can be used to identify local regions of pathology, and has been shown to be an indicator of response to therapy. Improved methods of assessing the microvasculature with non-invasive imaging modalities such as ultrasound will have an impact in biomedical theranostics. Ultrasound localization microscopy (ULM) is a new technology which allows processing of ultrasound data for visualization of microvasculature at a resolution better than allowed by acoustic diffraction with traditional ultrasound systems. Previous application of this modality in brain imaging has required the use of invasive procedures, such as a craniotomy, skull-thinning, or scalp removal, all of which are not feasible for the purpose of longitudinal studies. Methods: The impact of ultrasound localization microscopy is expanded using a 1024 channel matrix array ultrasonic transducer, four synchronized programmable ultrasound systems with customized high-performance hardware and software, and high-performance GPUs for processing. The potential of the imaging hardware and processing approaches are demonstrated in-vivo. Results: Our unique implementation allows asynchronous acquisition and data transfer for uninterrupted data collection at an ultra-high fixed frame rate. Using these methods, the vasculature was imaged using 100,000 volumes continuously at a volume acquisition rate of 500 volumes per second. With ULM, we achieved a resolution of 31 µm, which is a resolution improvement on conventional ultrasound imaging by nearly a factor of ten, in 3-D. This was accomplished while imaging through the intact skull with no scalp removal, which demonstrates the utility of this method for longitudinal studies. Conclusions: The results demonstrate new capabilities to rapidly image and analyze complex vascular networks in 3-D volume space for structural and functional imaging in disease assessment, targeted therapeutic delivery, monitoring response to therapy, and other theranostic applications.
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Affiliation(s)
- Jacob R McCall
- The Joint Department of Biomedical Engineering, UNC Chapel Hill and NC State University.,Electrical and Computer Engineering, NC State University
| | - Francisco Santibanez
- The Joint Department of Biomedical Engineering, UNC Chapel Hill and NC State University
| | - Hatim Belgharbi
- The Joint Department of Biomedical Engineering, UNC Chapel Hill and NC State University
| | - Gianmarco F Pinton
- The Joint Department of Biomedical Engineering, UNC Chapel Hill and NC State University
| | - Paul A Dayton
- The Joint Department of Biomedical Engineering, UNC Chapel Hill and NC State University
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Zlotnik D, Rabinski T, Halfon A, Anzi S, Plaschkes I, Benyamini H, Nevo Y, Gershoni OY, Rosental B, Hershkovitz E, Ben-Zvi A, Vatine GD. P450 oxidoreductase regulates barrier maturation by mediating retinoic acid metabolism in a model of the human BBB. Stem Cell Reports 2022; 17:2050-2063. [PMID: 35961311 PMCID: PMC9481905 DOI: 10.1016/j.stemcr.2022.07.010] [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: 05/26/2022] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 11/26/2022] Open
Abstract
The blood-brain barrier (BBB) selectively regulates the entry of molecules into the central nervous system (CNS). A crosstalk between brain microvascular endothelial cells (BMECs) and resident CNS cells promotes the acquisition of functional tight junctions (TJs). Retinoic acid (RA), a key signaling molecule during embryonic development, is used to enhance in vitro BBB models’ functional barrier properties. However, its physiological relevance and affected pathways are not fully understood. P450 oxidoreductase (POR) regulates the enzymatic activity of microsomal cytochromes. POR-deficient (PORD) patients display impaired steroid homeostasis and cognitive disabilities. Here, we used both patient-specific POR-deficient and CRISPR-Cas9-mediated POR-depleted induced pluripotent stem cell (iPSC)-derived BMECs (iBMECs) to study the role of POR in the acquisition of functional barrier properties. We demonstrate that POR regulates cellular RA homeostasis and that POR deficiency leads to the accumulation of RA within iBMECs, resulting in the impaired acquisition of TJs and, consequently, to dysfunctional development of barrier properties. Retinoic acid (RA) promotes functional barrier properties POR-deficient iPS-brain endothelial-like cells display impaired barrier development POR mediates CYP26-dependent cellular RA catabolism RA accumulation induces a pro-inflammatory response
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Affiliation(s)
- Dor Zlotnik
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Tatiana Rabinski
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Aviv Halfon
- Department of Developmental Biology and Cancer Research, the Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Shira Anzi
- Department of Developmental Biology and Cancer Research, the Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Inbar Plaschkes
- Bioinformatics Unit of the I-CORE Computation Center, the Hebrew University, Jerusalem 91120, Israel
| | - Hadar Benyamini
- Bioinformatics Unit of the I-CORE Computation Center, the Hebrew University, Jerusalem 91120, Israel
| | - Yuval Nevo
- Bioinformatics Unit of the I-CORE Computation Center, the Hebrew University, Jerusalem 91120, Israel
| | - Orly Yahalom Gershoni
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Benyamin Rosental
- The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Eli Hershkovitz
- Israel Pediatric Endocrinology and Diabetes Unit, Soroka University Medical Center, Beer Sheva, Israel
| | - Ayal Ben-Zvi
- Department of Developmental Biology and Cancer Research, the Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Gad D Vatine
- The Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Regenerative Medicine and Stem Cell (RMSC) Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.
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11
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Tissue Engineering Approaches to Uncover Therapeutic Targets for Endothelial Dysfunction in Pathological Microenvironments. Int J Mol Sci 2022; 23:ijms23137416. [PMID: 35806421 PMCID: PMC9266895 DOI: 10.3390/ijms23137416] [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: 06/17/2022] [Revised: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 02/07/2023] Open
Abstract
Endothelial cell dysfunction plays a central role in many pathologies, rendering it crucial to understand the underlying mechanism for potential therapeutics. Tissue engineering offers opportunities for in vitro studies of endothelial dysfunction in pathological mimicry environments. Here, we begin by analyzing hydrogel biomaterials as a platform for understanding the roles of the extracellular matrix and hypoxia in vascular formation. We next examine how three-dimensional bioprinting has been applied to recapitulate healthy and diseased tissue constructs in a highly controllable and patient-specific manner. Similarly, studies have utilized organs-on-a-chip technology to understand endothelial dysfunction's contribution to pathologies in tissue-specific cellular components under well-controlled physicochemical cues. Finally, we consider studies using the in vitro construction of multicellular blood vessels, termed tissue-engineered blood vessels, and the spontaneous assembly of microvascular networks in organoids to delineate pathological endothelial dysfunction.
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Cristofano G, Fucci M, Oliva MC, De Rinaldis M, Trabacca A. Peripheral circulation disturbances in two consecutive children with spinal muscular atrophy and literature review. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2022; 41:84-88. [PMID: 35832505 PMCID: PMC9237751 DOI: 10.36185/2532-1900-072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/11/2022] [Indexed: 11/06/2022]
Abstract
Spinal muscular atrophy is a progressive and severe hereditary (autosomal recessive) neuromuscular disease characterized by lower motor neuron degeneration in the spinal cord and brainstem causing a clinical picture of progressive muscle atrophy and weakness of skeletal and respiratory muscles. There is an ongoing discussion on the extent to which other tissues might be affected in patients with SMA. Several animal models and some case reports or small case series report involvement of other organ systems, such as peripheral nerve, brain, muscle, heart, vascular system, and pancreas. Recent literature reviews identified a number of cases with vascular abnormalities. We present two consecutive cases of patients diagnosed with SMA who developed peripheral circulation disturbances and combine the findings with a thorough review the literature.
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Affiliation(s)
| | | | | | | | - Antonio Trabacca
- Correspondence Antonio Trabacca Head of Unit for severe disabilities in developmental age and young adults (Developmental Neurology and Neurorehabilitation), Scientific Institute IRCCS “E. Medea”, ex Complesso Ospedaliero “A. Di Summa”, piazza “A. Di Summa”, 72100 Brindisi, Italy. Tel.: +39 083 1349611 (switchboard), +39 0831349643 (direct). Tel.: +39 083 1349612. E-mail:
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13
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Brunner C, Macé E, Montaldo G, Urban A. Quantitative Hemodynamic Measurements in Cortical Vessels Using Functional Ultrasound Imaging. Front Neurosci 2022; 16:831650. [PMID: 35495056 PMCID: PMC9039668 DOI: 10.3389/fnins.2022.831650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/23/2022] [Indexed: 01/17/2023] Open
Abstract
Red blood cell velocity (RBCv), cerebral blood flow (CBF), and volume (CBV) are three key parameters when describing brain hemodynamics. Functional ultrasound imaging is a Doppler-based method allowing for real-time measurement of relative CBV at high spatiotemporal resolution (100 × 110 × 300 μm3, up to 10 Hz) and large scale. Nevertheless, the measure of RBCv and CBF in small cortical vessels with functional ultrasound imaging remains challenging because of their orientation and size, which impairs the ability to perform precise measurements. We designed a directional flow filter to overpass these limitations allowing us to measure RBCv in single vessels using a standard functional ultrasound imaging system without contrast agents (e.g., microbubbles). This method allows to quickly extract the number of vessels in the cortex that was estimated to be approximately 650/cm3 in adult rats, with a 55–45% ratio for penetrating arterioles versus ascending venules. Then, we analyzed the changes in RBCv in these vessels during forepaw stimulation. We observed that ∼40 vessels located in the primary somatosensory forelimb cortex display a significant increase of the RBCv (median ΔRBCv ∼15%, maximal ΔRBCv ∼60%). As expected, we show that RBCv was higher for penetrating arterioles located in the center than in the periphery of the activated area. The proposed approach extends the capabilities of functional ultrasound imaging, which may contribute to a better understanding of the neurovascular coupling at the brain-wide scale.
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Affiliation(s)
- Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Emilie Macé
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
- *Correspondence: Alan Urban,
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Zhang Q, Turner KL, Gheres KW, Hossain MS, Drew PJ. Behavioral and physiological monitoring for awake neurovascular coupling experiments: a how-to guide. NEUROPHOTONICS 2022; 9:021905. [PMID: 35639834 PMCID: PMC8802326 DOI: 10.1117/1.nph.9.2.021905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/28/2021] [Indexed: 06/15/2023]
Abstract
Significance: Functional brain imaging in awake animal models is a popular and powerful technique that allows the investigation of neurovascular coupling (NVC) under physiological conditions. However, ubiquitous facial and body motions (fidgeting) are prime drivers of spontaneous fluctuations in neural and hemodynamic signals. During periods without movement, animals can rapidly transition into sleep, and the hemodynamic signals tied to arousal state changes can be several times larger than sensory-evoked responses. Given the outsized influence of facial and body motions and arousal signals in neural and hemodynamic signals, it is imperative to detect and monitor these events in experiments with un-anesthetized animals. Aim: To cover the importance of monitoring behavioral state in imaging experiments using un-anesthetized rodents, and describe how to incorporate detailed behavioral and physiological measurements in imaging experiments. Approach: We review the effects of movements and sleep-related signals (heart rate, respiration rate, electromyography, intracranial pressure, whisking, and other body movements) on brain hemodynamics and electrophysiological signals, with a focus on head-fixed experimental setup. We summarize the measurement methods currently used in animal models for detection of those behaviors and arousal changes. We then provide a guide on how to incorporate this measurements with functional brain imaging and electrophysiology measurements. Results: We provide a how-to guide on monitoring and interpreting a variety of physiological signals and their applications to NVC experiments in awake behaving mice. Conclusion: This guide facilitates the application of neuroimaging in awake animal models and provides neuroscientists with a standard approach for monitoring behavior and other associated physiological parameters in head-fixed animals.
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Affiliation(s)
- Qingguang Zhang
- The Pennsylvania State University, Center for Neural Engineering, Department of Engineering Science and Mechanics, University Park, Pennsylvania, United States
| | - Kevin L. Turner
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
| | - Kyle W. Gheres
- The Pennsylvania State University, Graduate Program in Molecular Cellular and Integrative Biosciences, University Park, Pennsylvania, United States
| | - Md Shakhawat Hossain
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
| | - Patrick J. Drew
- The Pennsylvania State University, Center for Neural Engineering, Department of Engineering Science and Mechanics, University Park, Pennsylvania, United States
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
- The Pennsylvania State University, Department of Neurosurgery, University Park, Pennsylvania, United States
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15
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Mentor S, Fisher D. The Ism between Endothelial Cilia and Endothelial Nanotubules Is an Evolving Concept in the Genesis of the BBB. Int J Mol Sci 2022; 23:ijms23052457. [PMID: 35269595 PMCID: PMC8910322 DOI: 10.3390/ijms23052457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023] Open
Abstract
The blood–brain barrier (BBB) is fundamental in maintaining central nervous system (CNS) homeostasis by regulating the chemical environment of the underlying brain parenchyma. Brain endothelial cells (BECs) constitute the anatomical and functional basis of the BBB. Communication between adjacent BECs is critical for establishing BBB integrity, and knowledge of its nanoscopic landscape will contribute to our understanding of how juxtaposed zones of tight-junction protein interactions between BECs are aligned. The review discusses and critiques types of nanostructures contributing to the process of BBB genesis. We further critically evaluate earlier findings in light of novel high-resolution electron microscopy descriptions of nanoscopic tubules. One such phenotypic structure is BEC cytoplasmic projections, which, early in the literature, is postulated as brain capillary endothelial cilia, and is evaluated and compared to the recently discovered nanotubules (NTs) formed in the paracellular spaces between BECs during barrier-genesis. The review attempts to elucidate a myriad of unique topographical ultrastructures that have been reported to be associated with the development of the BBB, viz., structures ranging from cilia to BEC tunneling nanotubules (TUNTs) and BEC tethering nanotubules (TENTs).
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Affiliation(s)
- Shireen Mentor
- Neurobiology Research Group, Department of Medical Biosciences, University of the Western Cape, Bellville, Cape Town 7535, South Africa;
| | - David Fisher
- Neurobiology Research Group, Department of Medical Biosciences, University of the Western Cape, Bellville, Cape Town 7535, South Africa;
- School of Health Professions, University of Missouri, Columbia, MO 65211, USA
- Correspondence:
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Abramo TJ, Szlam S, Hargrave H, Harris ZL, Williams A, Meredith M, Hedrick M, Hu Z, Nick T, Gonzalez CV. Bihemispheric Cerebral Oximetry Monitoring's Functionality in Suspected Cerebral Edema Diabetic Ketoacidosis With Therapeutic 3% Hyperosmolar Therapy in a Pediatric Emergency Department. Pediatr Emerg Care 2022; 38:e511-e518. [PMID: 30964851 DOI: 10.1097/pec.0000000000001774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Suspected cerebral edema diabetic ketoacidosis (SCEDKA) is more common than perceived with symptoms including altered mentation, headache with vomiting, depressed Glasgow coma scale (GCS), abnormal motor or verbal responses, combativeness, and neurological depression. Suspected cerebral edema diabetic ketoacidosis has been associated with initial diabetic ketoacidosis (DKA) presentation and at start of DKA therapy.Cerebral oximetry (bihemispheric regional cerebral oxygen saturation [rcSO2] and cerebral blood volume index [CBVI]) can detect increased intracranial pressure (ICP)-induced altered bihemispheric cerebral physiology (rcSO2) (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). In pediatrics, rcSO2 of less than 60% or rcSO2 of greater than 85% reflects increased ICP and cerebral edema (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700). Cerebral oximetry can detect increased ICP-induced altered bihemispheric cerebral physiology (rcSO2, CBVI) and cerebral physiological changes (rcSO2, CBVI changes) during therapeutic mechanical cerebral spinal fluid removal to decrease increased ICP (Crit Care Med 2006;34:2217-2223, J Pediatr 2013;163: 1111-1116, Curr Med Chem 2009;16:94-112, Diabetologia 1985;28:739-742, Pediatr Crit Care Med 2013;14:694-700).In the pediatric intensive care units, SCEDKA patients with nonbihemispheric cerebral oximetry showed an initial rcSO2 of greater than 90%. Bihemispheric rcSO2 with CBVI in SCEDKA patients has the potential to detect the abnormal cerebral physiology and disruptive autoregulation while detecting 3% hypertonic saline solution (HTS) effects on the SCEDKA altered cerebral physiology (rcSO2). PURPOSE The purposes of this study were to analyze and compare 3% HTS effect on bihemispheric rcSO2 readings, neurological and biochemical parameters in SCEDKA with 3% HTS infusion to non-SCEDKA patients in pediatric emergency department (PED). METHODS An observational retrospective comparative analysis study of bihemispheric rcSO2 readings, neurological and biochemical parameters in 2 groups of PED DKA patients were performed: PED DKA patients with SCEDKA +3% HTS infusions versus non-SCEDKA without 3% HTS infusions. RESULTS From 2008 to 2013, of the 1899 PED DKA patients, 60 SCEDKA patients received 3% HTS (5 mL/kg via peripheral intravenous) infusion (median age of 5 years [range, 3.7-7 years]), with 42 new DKA insulin dependent diabetes mellitus onset. Suspected cerebral edema diabetic ketoacidosis patients had GCS of 11 (range, 11-12), with consistent SCEDKA signs and symptoms (severe headaches with vomiting, confusion, blurred vision, altered speech, lethargy, and combativeness). Suspected cerebral edema diabetic ketoacidosis patients' initial (0-5 minutes) left rcSO2 readings were 91.4% (range, 88.4%-94.1%) and right was 90.3% (range, 88.6%-94.1%) compared with non-SCEDKA patients' left rcSO2 readings of 73.2% (range, 69.7%-77.8%) and right of 73.2% (range, 67.6%-77%) (P < 0.0001). The rcSO2 monitoring time before 3% HTS infusion was 54.9 minutes (range, 48.3-66.8 minutes) with 3% HTS time effect change: pre-3% HTS (54.9 minutes [range, 48.3-66.8 minutes]). Before 3% HTS infusion, the left rcSO2 readings were 90.0% (range, 89%-95%) and right was 91% (range, 86%-95%). The 30 to 45 minutes post-3% HTS showed that left was 64% (range, 62%-69%) and right was 65.4% (range, 63%-70%) (P < 0.0001). rcSO2 Δ change for post-3% HTS (0-20 minutes) to pre-3% HTS was as follows: left, -26.58 (-29.5 to -23.7) (P < 0.0001); right, -25.2 (-27.7 to -22.6) (P < 0.0001). Post-3% HTS GCS (14,15) and biochemistry compared with pre-3% HTS infusions all improved (P < 0.001). CONCLUSIONS In PED SCEDKA patients, the pre-3% HTS bihemispheric rcSO2 readings were greater than 90% and had lower GCS than non-SCEDKA patients. The post-3% HTS infusion rcSO2 readings showed within minutes a substantial reduction compared with non-SCEDKA patients, with no complications. Changes in rcSO2 readings after 3% HTS correlated with improved SCEDKA indicators (improved mental status, headache, and GCS) without any complications. We showed that cerebral oximetry in PED SCEDKA patients has shown an initial bihemispheric of greater than 90% readings signifying abnormal bihemispheric cerebral physiology. We also showed the cerebral oximetry's functionality in detecting 3% HTS therapeutic effects on SCEDKA's abnormal cerebral physiology and the beneficial therapeutic effects of 3% HTS infusion in SCEDKA patients. Using cerebral oximetry in pediatric DKA patients' initial cerebral assessment could have a significant impact in detecting SCEDKA patients. Further SCEDKA research using cerebral oximetry should be considered.
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Affiliation(s)
| | - Sarah Szlam
- Pediatric Emergency Medicine Associates, Atlanta, GA
| | | | - Zena Leah Harris
- Lurie Children's Hospital, Northwestern Feinberg School of Medicine, Chicago, IL
| | - Abby Williams
- Pediatric Emergency Medicine Associates, Atlanta, GA
| | - Mark Meredith
- Department of Pediatrics, College of Medicine, University of Tennessee, Memphis, TN
| | | | - Zhuopei Hu
- Division of Biostatistics ACHRI, Department of Pediatrics, Arkansas Children's Hospital Research Institute, College of Medicine, University of Arkansas, Little Rock, AR
| | - Todd Nick
- Division of Biostatistics ACHRI, Department of Pediatrics, Arkansas Children's Hospital Research Institute, College of Medicine, University of Arkansas, Little Rock, AR
| | - Cruz Velasco Gonzalez
- Division of Biostatistics ACHRI, Department of Pediatrics, Arkansas Children's Hospital Research Institute, College of Medicine, University of Arkansas, Little Rock, AR
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Li L, Law C, Marrett S, Chai Y, Huber L, Jezzard P, Bandettini P. Quantification of cerebral blood volume changes caused by visual stimulation at 3 T using DANTE-prepared dual-echo EPI. Magn Reson Med 2021; 87:1846-1862. [PMID: 34817081 DOI: 10.1002/mrm.29099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 10/07/2021] [Accepted: 11/05/2021] [Indexed: 11/12/2022]
Abstract
PURPOSE We investigate the influence of moving blood-attenuation effects when using "delay alternating with nutation for tailored excitation" (DANTE) pulses in conjunction with blood oxygen level dependent (BOLD) of functional MRI (fMRI) at 3 T. Based on the effects of including DANTE pulses, we propose quantification of cerebral blood volume (CBV) changes following functional stimulation. METHODS Eighteen volunteers in total underwent fMRI scans at 3 T. Seven volunteers were scanned to investigate the effects of DANTE pulses on the fMRI signal. CBV changes in response to visual stimulation were quantified in 11 volunteers using a DANTE-prepared dual-echo EPI sequence. RESULTS The inflow effects from flowing blood in arteries and draining vein effects from flowing blood in large veins can be suppressed by use of a DANTE preparation module. Using DANTE-prepared dual-echo EPI, we quantitatively measured intravascular-weighted microvascular CBV changes of 25.4%, 29.8%, and 32.6% evoked by 1, 5, and 10 Hz visual stimulation, respectively. The extravascular fraction (∆S/S)extra at TE = 30 ms in total BOLD signal was determined to be 64.8 ± 3.4%, which is in line with previous extravascular component estimation at 3 T. Results show that the microvascular CBV changes are linearly dependent on total BOLD changes at TE = 30 ms with a slope of 0.113, and this relation is independent of stimulation frequency and subject. CONCLUSION The DANTE preparation pulses can be incorporated into a standard EPI fMRI sequence for the purpose of minimizing inflow effects and reducing draining veins effects in large vessels. Additionally, the DANTE-prepared dual-echo EPI sequence is a promising fast imaging tool for quantification of intravascular-weighted CBV change in the microvascular space at 3 T.
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Affiliation(s)
- Linqing Li
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Christine Law
- Systems Neuroscience and Pain Lab, Stanford University, Stanford, California, USA
| | - Sean Marrett
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Yuhui Chai
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Laurentius Huber
- MR-Methods Group, MBIC, FPN, Maastricht University, Maastricht, Netherlands
| | - Peter Jezzard
- Wellcome Centre for Integrative Neuroimaging, FMRIB Division, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Peter Bandettini
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
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Polozova Anastasia V, Boyarinov Gennadii A, Nikolsky Viktor O, Zolotova Marina V, Deryugina Anna V. The functional indexes of RBCs and microcirculation in the traumatic brain injury with the action of 2-ethil-6-methil-3-hydroxypiridin succinate. BMC Neurosci 2021; 22:57. [PMID: 34525969 PMCID: PMC8442361 DOI: 10.1186/s12868-021-00657-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 08/25/2021] [Indexed: 11/10/2022] Open
Abstract
RESEARCH AIM To study the RBCs functional and metabolic parameters and the microcirculatory brain structure at traumatic brain injury (TBI) under the action of 2-ethyl-6-methyl-3-hydroxypyridine succinate. METHODS A closed TBI was modeled by the free fall of a load on the parietooccipital regions of head. We made studies of the influence of 2-ethil-6-methil-3-hydroxipiridin succinate on aggregation and electrophoretic mobility of RBCs, catalase activity, malonic dialdehyde concentration, adenosine triphosphate and 2.3-biphosphoglycerate (2.3 - BPG) concentrations in RBCs. The state of parenchyma and microcirculatory brain mainstream in post-traumatic period of TBI have been studied on micro-preparations. RESULTS The use of 2-ethyl-6-methyl-3-hydroxypyridine succinate under conditions of head injury leads to a decrease in MDA concentration and in aggregation of RBCs, to an increase in the 2.3-BPG concentration and RBC electrophoretic mobility compared to the control (group value). The most pronounced changes under the action of 2-ethyl-6-methyl-3-hydroxypyridine succinate were observed 3-7 days after the TBI. Significant indicators of the restoration of the microvasculature and brain tissue provoked by the use of 2-ethyl-6-methyl-3-hydroxypyridine succinate of were evident from the 7th day unlike the control group, where the restoration of structural morphological parameters was observed only on the 12th day of the post-traumatic period. Fast recovery of blood flow under the action of 2-ethyl-6-methyl-3-hydroxypyridine succinate ensured effective restoration of neurons and glia in comparison with the control group. CONCLUSIONS Early and long-term cytoprotective correction intensifies the oxygen transport function of the blood, prevents and / or reduces disorders of microvessels, neurons and glia in the post-traumatic period, thereby provides correction of hypoxic state and drives to the restoration of brain tissues homeostasis.
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Affiliation(s)
- V Polozova Anastasia
- Department of Physiology and Anatomy, Institute of Biology and Biomedicine, Lobachevsky University, 23 Gagarin Ave., Nizhny Novgorod, Russia. .,Department of Anesthesiology and Intensive Care, Privolzhsky Research Medical University of the Ministry of Health of the Russian Federation, Nizhny Novgorod, Russia.
| | - A Boyarinov Gennadii
- Department of Anesthesiology and Intensive Care, Privolzhsky Research Medical University of the Ministry of Health of the Russian Federation, Nizhny Novgorod, Russia
| | - O Nikolsky Viktor
- Department of Anesthesiology and Intensive Care, Privolzhsky Research Medical University of the Ministry of Health of the Russian Federation, Nizhny Novgorod, Russia
| | - V Zolotova Marina
- Department of Physiology and Anatomy, Institute of Biology and Biomedicine, Lobachevsky University, 23 Gagarin Ave., Nizhny Novgorod, Russia
| | - V Deryugina Anna
- Department of Physiology and Anatomy, Institute of Biology and Biomedicine, Lobachevsky University, 23 Gagarin Ave., Nizhny Novgorod, Russia
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Bracko O, Cruz Hernández JC, Park L, Nishimura N, Schaffer CB. Causes and consequences of baseline cerebral blood flow reductions in Alzheimer's disease. J Cereb Blood Flow Metab 2021; 41:1501-1516. [PMID: 33444096 PMCID: PMC8221770 DOI: 10.1177/0271678x20982383] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/27/2020] [Accepted: 11/16/2020] [Indexed: 12/23/2022]
Abstract
Reductions of baseline cerebral blood flow (CBF) of ∼10-20% are a common symptom of Alzheimer's disease (AD) that appear early in disease progression and correlate with the severity of cognitive impairment. These CBF deficits are replicated in mouse models of AD and recent work shows that increasing baseline CBF can rapidly improve the performance of AD mice on short term memory tasks. Despite the potential role these data suggest for CBF reductions in causing cognitive symptoms and contributing to brain pathology in AD, there remains a poor understanding of the molecular and cellular mechanisms causing them. This review compiles data on CBF reductions and on the correlation of AD-related CBF deficits with disease comorbidities (e.g. cardiovascular and genetic risk factors) and outcomes (e.g. cognitive performance and brain pathology) from studies in both patients and mouse models, and discusses several potential mechanisms proposed to contribute to CBF reductions, based primarily on work in AD mouse models. Future research aimed at improving our understanding of the importance of and interplay between different mechanisms for CBF reduction, as well as at determining the role these mechanisms play in AD patients could guide the development of future therapies that target CBF reductions in AD.
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Affiliation(s)
- Oliver Bracko
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Jean C Cruz Hernández
- Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Laibaik Park
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY, USA
| | - Nozomi Nishimura
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
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Salinet J, Moura FSD, Romanelli R, Dos Santos PMN, Zamai M, Panerai RB, Duarte AM, Bor-Seng-Shu E, Salinet ASM. CAAos platform: an integrated platform for analysis of cerebral hemodynamics data. Physiol Meas 2021; 42. [PMID: 34134102 DOI: 10.1088/1361-6579/ac0c0b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 06/16/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The purpose of this article is to introduce the readers to the concept and structure of CAAos (Cerebral Autoregulation Assessment Open Source) platform, and provide evidence of its functionality. APPROACH CAAos platform is a new open-source software research tool, developed in Python 3 language, that combines existing and novel methods for interactive visual inspection, batch processing and analysis of multichannel records. The platform is scalable, allowing for customization and inclusion of new tools. MAIN RESULTS Currently CAAos platform is composed of two main modules, preprocessing (containing artefact removal, filtering and signal beat to beat extraction tools) and cerebral autoregulation (CA) analysis modules. Two methods for assessing CA have been implemented into CAAos platform: transfer function analysis (TFA) and autoregulation index (ARI). In order to provide validation of TFA and ARI estimates derived from CAAos platform, the results were compared with those derived from two other algorithms. Validation was performed using data from twenty-eight participants, corresponding to 13 acute ischemic stroke patients and 13 age- and sex-matched control subjects. Agreement between estimates was assessed by intraclass correlation coefficient and Bland-Altman analysis. No significant statistical difference between algorithms was found. Moreover, there was an excellent correspondence between the curves of all parameters analysed, with intraclass correlation coefficient ranging from 0.98 (95%CI 0.976-0.999) to 1.00 (95%CI 1 -1). The mean differences revealed a very small magnitude bias indicating an excellent agreement between the estimates. SIGNIFICANCE As open-source software, the source code for the software is freely available for non-commercial use, reducing barriers to performing CA analysis, allowing inspection of the inner-workings of the algorithms, and facilitating networked activities with common standards. CAAos platform is a tailored software solution for the scientific community in the cerebral hemodynamic field and contributes to increasing use and reproducibility of CA assessment.
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Affiliation(s)
- João Salinet
- Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
| | - Fernando Silva de Moura
- Biomedical Engineering, Engineering, Modelling and Applied Social Sciences Centre, Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
| | - Renata Romanelli
- Biomedical Engineering, Engineering, Modelling and Applied Social Sciences Centre, Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
| | - Pedro Machado Nery Dos Santos
- Biomedical Engineering, Engineering, Modelling and Applied Social Sciences Centre, Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
| | - Matheus Zamai
- Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
| | - Ronney B Panerai
- Department of Medical Physics and Clinical Engineering, Leicester Royal Infirmary, Infirmary Square, LEICESTER, LE1 5WW, Leicester, Leicestershire, LE2 7LX, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Andre M Duarte
- Biomedical Engineering, Engineering, Modelling and Applied Social Sciences Centre, Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
| | - Edson Bor-Seng-Shu
- Neurology, University of Sao Paulo Hospital of Clinics, Sao Paulo, São Paulo, BRAZIL
| | - Angela Salomao Macedo Salinet
- Biomedical Engineering, Engineering, Modelling and Applied Social Sciences Centre, Federal University of the ABC Engineering Modeling and Applied Social Sciences Center Sao Bernardo do Campo, Sao Bernardo do Campo, São Paulo, BRAZIL
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21
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Girolamo F, de Trizio I, Errede M, Longo G, d'Amati A, Virgintino D. Neural crest cell-derived pericytes act as pro-angiogenic cells in human neocortex development and gliomas. Fluids Barriers CNS 2021; 18:14. [PMID: 33743764 PMCID: PMC7980348 DOI: 10.1186/s12987-021-00242-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/13/2021] [Indexed: 02/07/2023] Open
Abstract
Central nervous system diseases involving the parenchymal microvessels are frequently associated with a ‘microvasculopathy’, which includes different levels of neurovascular unit (NVU) dysfunction, including blood–brain barrier alterations. To contribute to the understanding of NVU responses to pathological noxae, we have focused on one of its cellular components, the microvascular pericytes, highlighting unique features of brain pericytes with the aid of the analyses carried out during vascularization of human developing neocortex and in human gliomas. Thanks to their position, centred within the endothelial/glial partition of the vessel basal lamina and therefore inserted between endothelial cells and the perivascular and vessel-associated components (astrocytes, oligodendrocyte precursor cells (OPCs)/NG2-glia, microglia, macrophages, nerve terminals), pericytes fulfil a central role within the microvessel NVU. Indeed, at this critical site, pericytes have a number of direct and extracellular matrix molecule- and soluble factor-mediated functions, displaying marked phenotypical and functional heterogeneity and carrying out multitasking services. This pericytes heterogeneity is primarily linked to their position in specific tissue and organ microenvironments and, most importantly, to their ontogeny. During ontogenesis, pericyte subtypes belong to two main embryonic germ layers, mesoderm and (neuro)ectoderm, and are therefore expected to be found in organs ontogenetically different, nonetheless, pericytes of different origin may converge and colonize neighbouring areas of the same organ/apparatus. Here, we provide a brief overview of the unusual roles played by forebrain pericytes in the processes of angiogenesis and barriergenesis by virtue of their origin from midbrain neural crest stem cells. A better knowledge of the ontogenetic subpopulations may support the understanding of specific interactions and mechanisms involved in pericyte function/dysfunction, including normal and pathological angiogenesis, thereby offering an alternative perspective on cell subtype-specific therapeutic approaches. ![]()
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Affiliation(s)
- Francesco Girolamo
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy.
| | - Ignazio de Trizio
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy.,Intensive Care Unit, Department of Intensive Care, Regional Hospital of Lugano, Ente Ospedaliero Cantonale, Lugano, Switzerland
| | - Mariella Errede
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy
| | - Giovanna Longo
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, Molecular Biology Unit, University of Bari School of Medicine, Bari, Italy
| | - Antonio d'Amati
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy.,Department of Emergency and Organ Transplantation, Pathology Section, University of Bari School of Medicine, Bari, Italy
| | - Daniela Virgintino
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy
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22
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Girolamo F, de Trizio I, Errede M, Longo G, d’Amati A, Virgintino D. Neural crest cell-derived pericytes act as pro-angiogenic cells in human neocortex development and gliomas. Fluids Barriers CNS 2021. [DOI: 10.1186/s12987-021-00242-7 union select null--] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractCentral nervous system diseases involving the parenchymal microvessels are frequently associated with a ‘microvasculopathy’, which includes different levels of neurovascular unit (NVU) dysfunction, including blood–brain barrier alterations. To contribute to the understanding of NVU responses to pathological noxae, we have focused on one of its cellular components, the microvascular pericytes, highlighting unique features of brain pericytes with the aid of the analyses carried out during vascularization of human developing neocortex and in human gliomas. Thanks to their position, centred within the endothelial/glial partition of the vessel basal lamina and therefore inserted between endothelial cells and the perivascular and vessel-associated components (astrocytes, oligodendrocyte precursor cells (OPCs)/NG2-glia, microglia, macrophages, nerve terminals), pericytes fulfil a central role within the microvessel NVU. Indeed, at this critical site, pericytes have a number of direct and extracellular matrix molecule- and soluble factor-mediated functions, displaying marked phenotypical and functional heterogeneity and carrying out multitasking services. This pericytes heterogeneity is primarily linked to their position in specific tissue and organ microenvironments and, most importantly, to their ontogeny. During ontogenesis, pericyte subtypes belong to two main embryonic germ layers, mesoderm and (neuro)ectoderm, and are therefore expected to be found in organs ontogenetically different, nonetheless, pericytes of different origin may converge and colonize neighbouring areas of the same organ/apparatus. Here, we provide a brief overview of the unusual roles played by forebrain pericytes in the processes of angiogenesis and barriergenesis by virtue of their origin from midbrain neural crest stem cells. A better knowledge of the ontogenetic subpopulations may support the understanding of specific interactions and mechanisms involved in pericyte function/dysfunction, including normal and pathological angiogenesis, thereby offering an alternative perspective on cell subtype-specific therapeutic approaches.
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23
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Tang J, Kilic K, Szabo TL, Boas DA. Improved Color Doppler for Cerebral Blood Flow Axial Velocity Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:758-764. [PMID: 33156785 PMCID: PMC8098776 DOI: 10.1109/tmi.2020.3036468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Conventional color Doppler ultrasound imaging suffers from mutual frequency cancellation when applied to quantify axial blood flow velocities in the rodent brain where inverse flows exist within an ultrasound measurement voxel. Here, we report an improved color Doppler-based functional ultrasound imaging method (iCD-fUS) for axial blood flow velocity imaging of the rodent brain. By applying a directional filter and high frequency noise thresholding, iCD-fUS is able to accurately quantify blood flow velocities within the brain as validated with the ultrasound localization microscopy velocimetry method. We show that iCD-fUS is able to image and resolve the directional axial blood flow velocity throughout the entire coronal section of the brain at a temporal frame rate of up to 10 Hz with a spatial resolution of ~100 [Formula: see text]. We further applied iCD-fUS to image the axial blood flow velocity change in response to whisker stimulation in an awake mouse, showing its potential for studying brain activation. With these capabilities, iCD-fUS provides a powerful, quantitative tool for in vivo chronic research.
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24
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Ding X, Peng D. Transient Global Amnesia: An Electrophysiological Disorder Based on Cortical Spreading Depression-Transient Global Amnesia Model. Front Hum Neurosci 2020; 14:602496. [PMID: 33363460 PMCID: PMC7753037 DOI: 10.3389/fnhum.2020.602496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/17/2020] [Indexed: 01/09/2023] Open
Abstract
Transient global amnesia (TGA) is a benign memory disorder with etiologies that have been debated for a long time. The prevalence of stressful events before a TGA attack makes it hard to overlook these precipitating factors, given that stress has the potential to organically effect the brain. Cortical spreading depression (CSD) was proposed as a possible cause decades ago. Being a regional phenomenon, CSD seems to affect every aspect of the micro-mechanism in maintaining the homeostasis of the central nervous system (CNS). Corresponding evidence regarding hemodynamic and morphological changes from TGA and CSD have been accumulated separately, but the resemblance between the two has not been systematically explored so far, which is surprising especially considering that CSD had been confirmed to cause secondary damage in the human brain. Thus, by deeply delving into the anatomic and electrophysiological properties of the CNS, the CSD-TGA model may render insights into the basic pathophysiology behind the façade of the enigmatic clinical presentation.
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Affiliation(s)
- Xuejiao Ding
- Department of Neurology, China-Japan Friendship Hospital, Beijing, China
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Dantao Peng
- Department of Neurology, China-Japan Friendship Hospital, Beijing, China
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25
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Fan JL, Rivera JA, Sun W, Peterson J, Haeberle H, Rubin S, Ji N. High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics. Nat Commun 2020; 11:6020. [PMID: 33243995 PMCID: PMC7693336 DOI: 10.1038/s41467-020-19851-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 10/13/2020] [Indexed: 02/02/2023] Open
Abstract
Understanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.
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Affiliation(s)
- Jiang Lan Fan
- University of California, Berkeley, CA, USA.,University of California, San Francisco, CA, USA
| | - Jose A Rivera
- Department of Physics, University of California, Berkeley, CA, USA
| | - Wei Sun
- Thorlabs Imaging Systems, Sterling, VA, USA
| | | | | | - Sam Rubin
- Thorlabs Imaging Systems, Sterling, VA, USA.,LightPath Technologies Inc., Orlando, FL, USA
| | - Na Ji
- Department of Physics, University of California, Berkeley, CA, USA. .,Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. .,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA. .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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26
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Quelhas P, Baltazar G, Cairrao E. The Neurovascular Unit: Focus on the Regulation of Arterial Smooth Muscle Cells. Curr Neurovasc Res 2020; 16:502-515. [PMID: 31738142 DOI: 10.2174/1567202616666191026122642] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/01/2019] [Accepted: 09/20/2019] [Indexed: 02/08/2023]
Abstract
The neurovascular unit is a physiological unit present in the brain, which is constituted by elements of the nervous system (neurons and astrocytes) and the vascular system (endothelial and mural cells). This unit is responsible for the homeostasis and regulation of cerebral blood flow. There are two major types of mural cells in the brain, pericytes and smooth muscle cells. At the arterial level, smooth muscle cells are the main components that wrap around the outside of cerebral blood vessels and the major contributors to basal tone maintenance, blood pressure and blood flow distribution. They present several mechanisms by which they regulate both vasodilation and vasoconstriction of cerebral blood vessels and their regulation becomes even more important in situations of injury or pathology. In this review, we discuss the main regulatory mechanisms of brain smooth muscle cells and their contributions to the correct brain homeostasis.
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Affiliation(s)
- Patrícia Quelhas
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
| | - Graça Baltazar
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
| | - Elisa Cairrao
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
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27
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Ashley JD, Shelley JH, Sun J, Song J, Trent JA, Ambrosio LD, Larson DJ, Larson RD, Yabluchanskiy A, Kellawan JM. Cerebrovascular responses to graded exercise in young healthy males and females. Physiol Rep 2020; 8:e14622. [PMID: 33112497 PMCID: PMC7592493 DOI: 10.14814/phy2.14622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 10/04/2020] [Indexed: 01/06/2023] Open
Abstract
Although systemic sex-specific differences in cardiovascular responses to exercise are well established, the comparison of sex-specific cerebrovascular responses to exercise has gone under-investigated especially, during high intensity exercise. Therefore, our purpose was to compare cerebrovascular responses in males and females throughout a graded exercise test (GXT). Twenty-six participants (13 Females and 13 Males, 24 ± 4 yrs.) completed a GXT on a recumbent cycle ergometer consisting of 3-min stages. Each sex completed 50W, 75W, 100W stages. Thereafter, power output increased 30W/stage for females and 40W/stage for males until participants were unable to maintain 60-80 RPM. The final stage completed by the participant was considered maximum workload(Wmax ). Respiratory gases (End-tidal CO2 , EtCO2 ), middle cerebral artery blood velocity (MCAv), heart rate (HR), non-invasive mean arterial pressure (MAP), cardiac output (CO), and stroke volume (SV) were continuously recorded on a breath-by-breath or beat-by-beat basis. Cerebral perfusion pressure, CPP = MAP (0. 7,355 distance from heart-level to doppler probe) and cerebral vascular conductance index, CVCi = MCAv/CPP 100mmHg were calculated. The change from baseline (Δ) in MCAv was similar between the sexes during the GXT (p = .091, ωp2 = 0.05). However, ΔCPP (p < .001, ωp2 = 0.25) was greater in males at intensities ≥ 80% Wmax and ΔCVCi (p = .005, ωp2 = 0.15) was greater in females at 100% Wmax . Δ End-tidal CO2 (ΔEtCO2 ) was not different between the sexes during exercise (p = .606, ωp2 = -0.03). These data suggest there are sex-specific differences in cerebrovascular control, and these differences may only be identifiable at high and severe intensity exercise.
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Affiliation(s)
- John D. Ashley
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Joe H. Shelley
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Jongjoo Sun
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Jiwon Song
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Jacob A. Trent
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Luis D. Ambrosio
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Daniel J. Larson
- Department of Health and Exercise Science, Sport, Health, and Exercise Data Analytics LaboratoryUniversity of OklahomaNormanOKUSA
| | - Rebecca D. Larson
- Department of Health and Exercise ScienceBody Composition and Physical Performance Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Andriy Yabluchanskiy
- Oklahoma Center for GeroscienceDepartment of Biochemistry and Molecular BiologyUniversity of Oklahoma Health Sciences CenterOklahoma CityOKUSA
| | - J. Mikhail Kellawan
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
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28
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Vendel E, Rottschäfer V, de Lange ECM. A 3D brain unit model to further improve prediction of local drug distribution within the brain. PLoS One 2020; 15:e0238397. [PMID: 32966285 PMCID: PMC7511021 DOI: 10.1371/journal.pone.0238397] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/15/2020] [Indexed: 12/14/2022] Open
Abstract
The development of drugs targeting the brain still faces a high failure rate. One of the reasons is a lack of quantitative understanding of the complex processes that govern the pharmacokinetics (PK) of a drug within the brain. While a number of models on drug distribution into and within the brain is available, none of these addresses the combination of factors that affect local drug concentrations in brain extracellular fluid (brain ECF). Here, we develop a 3D brain unit model, which builds on our previous proof-of-concept 2D brain unit model, to understand the factors that govern local unbound and bound drug PK within the brain. The 3D brain unit is a cube, in which the brain capillaries surround the brain ECF. Drug concentration-time profiles are described in both a blood-plasma-domain and a brain-ECF-domain by a set of differential equations. The model includes descriptions of blood plasma PK, transport through the blood-brain barrier (BBB), by passive transport via paracellular and transcellular routes, and by active transport, and drug binding kinetics. The impact of all these factors on ultimate local brain ECF unbound and bound drug concentrations is assessed. In this article we show that all the above mentioned factors affect brain ECF PK in an interdependent manner. This indicates that for a quantitative understanding of local drug concentrations within the brain ECF, interdependencies of all transport and binding processes should be understood. To that end, the 3D brain unit model is an excellent tool, and can be used to build a larger network of 3D brain units, in which the properties for each unit can be defined independently to reflect local differences in characteristics of the brain.
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Affiliation(s)
- Esmée Vendel
- Mathematical Institute, Leiden University, Leiden, The Netherlands
| | - Vivi Rottschäfer
- Mathematical Institute, Leiden University, Leiden, The Netherlands
- * E-mail: (VR); (EL)
| | - Elizabeth C. M. de Lange
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
- * E-mail: (VR); (EL)
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29
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Francisco DMF, Marchetti L, Rodríguez-Lorenzo S, Frías-Anaya E, Figueiredo RM, Winter P, Romero IA, de Vries HE, Engelhardt B, Bruggmann R. Advancing brain barriers RNA sequencing: guidelines from experimental design to publication. Fluids Barriers CNS 2020; 17:51. [PMID: 32811511 PMCID: PMC7433166 DOI: 10.1186/s12987-020-00207-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/06/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND RNA sequencing (RNA-Seq) in its varied forms has become an indispensable tool for analyzing differential gene expression and thus characterization of specific tissues. Aiming to understand the brain barriers genetic signature, RNA seq has also been introduced in brain barriers research. This has led to availability of both, bulk and single-cell RNA-Seq datasets over the last few years. If appropriately performed, the RNA-Seq studies provide powerful datasets that allow for significant deepening of knowledge on the molecular mechanisms that establish the brain barriers. However, RNA-Seq studies comprise complex workflows that require to consider many options and variables before, during and after the proper sequencing process. MAIN BODY In the current manuscript, we build on the interdisciplinary experience of the European PhD Training Network BtRAIN ( https://www.btrain-2020.eu/ ) where bioinformaticians and brain barriers researchers collaborated to analyze and establish RNA-Seq datasets on vertebrate brain barriers. The obstacles BtRAIN has identified in this process have been integrated into the present manuscript. It provides guidelines along the entire workflow of brain barriers RNA-Seq studies starting from the overall experimental design to interpretation of results. Focusing on the vertebrate endothelial blood-brain barrier (BBB) and epithelial blood-cerebrospinal-fluid barrier (BCSFB) of the choroid plexus, we provide a step-by-step description of the workflow, highlighting the decisions to be made at each step of the workflow and explaining the strengths and weaknesses of individual choices made. Finally, we propose recommendations for accurate data interpretation and on the information to be included into a publication to ensure appropriate accessibility of the data and reproducibility of the observations by the scientific community. CONCLUSION Next generation transcriptomic profiling of the brain barriers provides a novel resource for understanding the development, function and pathology of these barrier cells, which is essential for understanding CNS homeostasis and disease. Continuous advancement and sophistication of RNA-Seq will require interdisciplinary approaches between brain barrier researchers and bioinformaticians as successfully performed in BtRAIN. The present guidelines are built on the BtRAIN interdisciplinary experience and aim to facilitate collaboration of brain barriers researchers with bioinformaticians to advance RNA-Seq study design in the brain barriers community.
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Affiliation(s)
- David M F Francisco
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - Luca Marchetti
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Sabela Rodríguez-Lorenzo
- MS Center Amsterdam, Amsterdam Neuroscience, Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Eduardo Frías-Anaya
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes, UK
| | - Ricardo M Figueiredo
- GenXPro GmbH, Frankfurt/Main, Germany
- Johann Wolfgang Goethe University, Frankfurt/Main, Germany
| | | | - Ignacio Andres Romero
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes, UK
| | - Helga E de Vries
- MS Center Amsterdam, Amsterdam Neuroscience, Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | | | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland.
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30
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Abstract
PURPOSE To review the recent developments on the effect of chronic high mean arterial blood pressure (MAP) on cerebral blood flow (CBF) autoregulation and supporting the notion that CBF autoregulation impairment has connection with chronic cerebral diseases. Method: A narrative review of all the relevant papers known to the authors was conducted. Results: Our understanding of the connection between cerebral perfusion impairment and chronic high MAP and cerebral disease is rapidly evolving, from cerebral perfusion impairment being the result of cerebral diseases to being the cause of cerebral diseases. We now better understand the intertwined impact of hypertension and Alzheimer's disease (AD) on cerebrovascular sensory elements and recognize cerebrovascular elements that are more vulnerable to these diseases. Conclusion: We conclude with the suggestion that the sensory elements pathology plays important roles in intertwined mechanisms of chronic high MAP and AD that impact cerebral perfusion.
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Affiliation(s)
- Noushin Yazdani
- College of Public Health, University of South Florida , Tampa, FL, USA
| | - Mark S Kindy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Biomedical Research, James A. Haley VA Medical Center , Tampa, FL, USA
| | - Saeid Taheri
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Byrd Neuroscience Institute, University of South Florida , Tampa, FL, USA
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31
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Uemura MT, Maki T, Ihara M, Lee VMY, Trojanowski JQ. Brain Microvascular Pericytes in Vascular Cognitive Impairment and Dementia. Front Aging Neurosci 2020; 12:80. [PMID: 32317958 PMCID: PMC7171590 DOI: 10.3389/fnagi.2020.00080] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/04/2020] [Indexed: 12/19/2022] Open
Abstract
Pericytes are unique, multi-functional mural cells localized at the abluminal side of the perivascular space in microvessels. Originally discovered in 19th century, pericytes had drawn less attention until decades ago mainly due to lack of specific markers. Recently, however, a growing body of evidence has revealed that pericytes play various important roles: development and maintenance of blood–brain barrier (BBB), regulation of the neurovascular system (e.g., vascular stability, vessel formation, cerebral blood flow, etc.), trafficking of inflammatory cells, clearance of toxic waste products from the brain, and acquisition of stem cell-like properties. In the neurovascular unit, pericytes perform these functions through coordinated crosstalk with neighboring cells including endothelial, glial, and neuronal cells. Dysfunction of pericytes contribute to a wide variety of diseases that lead to cognitive impairments such as cerebral small vessel disease (SVD), acute stroke, Alzheimer’s disease (AD), and other neurological disorders. For instance, in SVDs, pericyte degeneration leads to microvessel instability and demyelination while in stroke, pericyte constriction after ischemia causes a no-reflow phenomenon in brain capillaries. In AD, which shares some common risk factors with vascular dementia, reduction in pericyte coverage and subsequent microvascular impairments are observed in association with white matter attenuation and contribute to impaired cognition. Pericyte loss causes BBB-breakdown, which stagnates amyloid β clearance and the leakage of neurotoxic molecules into the brain parenchyma. In this review, we first summarize the characteristics of brain microvessel pericytes, and their roles in the central nervous system. Then, we focus on how dysfunctional pericytes contribute to the pathogenesis of vascular cognitive impairment including cerebral ‘small vessel’ and ‘large vessel’ diseases, as well as AD. Finally, we discuss therapeutic implications for these disorders by targeting pericytes.
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Affiliation(s)
- Maiko T Uemura
- Institute on Aging and Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.,JSPS Overseas Research Fellowship Program, Japan Society for the Promotion of Science, Tokyo, Japan
| | - Takakuni Maki
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masafumi Ihara
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Virginia M Y Lee
- Institute on Aging and Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - John Q Trojanowski
- Institute on Aging and Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Lu Y, Lu X, Zhang C, Marchand PJ, Lesage F. Longitudinal optical coherence tomography imaging of tissue repair and microvasculature regeneration and function after targeted cerebral ischemia. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-15. [PMID: 32285652 PMCID: PMC7152803 DOI: 10.1117/1.jbo.25.4.046002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE Understanding how the brain recovers from cerebral tissue and vascular damage after an ischemic event can help develop new therapeutic strategies for the treatment of stroke. AIM We investigated cerebral tissue repair and microvasculature regeneration and function after a targeted ischemic stroke. APPROACH Following photothrombosis occlusion of microvasculature, chronic optical coherence tomography (OCT)-based angiography was used to track ischemic tissue repair and microvasculature regeneration at three different cortical depths and up to 28 days in awake animals. Capillary network orientation analysis was performed to study the structural pattern of newly formed microvasculature. Based on the time-resolved OCT-angiography, we also investigated capillary stalling, which is likely related to ischemic stroke-induced inflammation. RESULTS Deeper cerebral tissue was found to have a larger ischemic area than shallower regions at any time point during the course of poststroke recovery, which suggests that cerebral tissue located deep in the cortex is more vulnerable. Regenerated microvasculature had a highly organized pattern at all cortical depths with a higher degree of structural reorganization in deeper regions. Additionally, capillary stalling event analysis revealed that cerebral ischemia augmented stalling events considerably. CONCLUSION Longitudinal OCT angiography reveals that regenerated capillary network has a highly directional pattern and an increased density and incidence of capillary stalling event.
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Affiliation(s)
- Yuankang Lu
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
| | - Xuecong Lu
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
| | - Cong Zhang
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
- Université de Montreal, Montréal, Québec, Canada
| | - Paul J. Marchand
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
| | - Frédéric Lesage
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
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Abnormal neurovascular coupling as a cause of excess cerebral vasodilation in familial migraine. Cardiovasc Res 2019; 116:2009-2020. [DOI: 10.1093/cvr/cvz306] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/16/2019] [Accepted: 11/07/2019] [Indexed: 12/27/2022] Open
Abstract
Abstract
Aims
Acute migraine attack in familial hemiplegic migraine type 2 (FHM2) patients is characterized by sequential hypo- and hyperperfusion. FHM2 is associated with mutations in the Na, K-ATPase α2 isoform. Heterozygous mice bearing one of these mutations (α2+/G301R mice) were shown to have elevated cerebrovascular tone and, thus, hypoperfusion that might lead to elevated concentrations of local metabolites. We hypothesize that these α2+/G301R mice also have increased cerebrovascular hyperaemic responses to these local metabolites leading to hyperperfusion in the affected part of the brain.
Methods and results
Neurovascular coupling was compared in α2+/G301R and matching wild-type (WT) mice using Laser Speckle Contrast Imaging. In brain slices, parenchymal arteriole diameter and intracellular calcium changes in neuronal tissue, astrocytic endfeet, and smooth muscle cells in response to neuronal excitation were assessed. Wall tension and smooth muscle membrane potential were measured in isolated middle cerebral arteries. Quantitative polymerase chain reaction, western blot, and immunohistochemistry were used to assess the molecular background underlying the functional changes. Whisker stimulation induced larger increase in blood perfusion, i.e. hyperaemic response, of the somatosensory cortex of α2+/G301R than WT mice. Neuronal excitation was associated with larger parenchymal arteriole dilation in brain slices from α2+/G301R than WT mice. These hyperaemic responses in vivo and ex vivo were inhibited by BaCl2, suggesting involvement of inward-rectifying K+ channels (Kir). Relaxation to elevated bath K+ was larger in arteries from α2+/G301R compared to WT mice. This difference was endothelium-dependent. Endothelial Kir2.1 channel expression was higher in arteries from α2+/G301R mice. No sex difference in functional responses and Kir2.1 expression was found.
Conclusion
This study suggests that an abnormally high cerebrovascular hyperaemic response in α2+/G301R mice is a result of increased endothelial Kir2.1 channel expression. This may be initiated by vasospasm-induced accumulation of local metabolites and underlie the hyperperfusion seen in FHM2 patients during migraine attack.
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Lu Y, Zhang C, Lu X, Moeini M, Thorin E, Lesage F. Impact of atherosclerotic disease on cerebral microvasculature and tissue oxygenation in awake LDLR-/-hApoB+/+ transgenic mice. NEUROPHOTONICS 2019; 6:045003. [PMID: 31673566 PMCID: PMC6811703 DOI: 10.1117/1.nph.6.4.045003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/17/2019] [Indexed: 05/17/2023]
Abstract
We explore cortical microvasculature changes during the progression of atherosclerosis using young and old transgenic atherosclerotic (ATX) mice with thinned-skull cranial window. In awake animals, exploiting intrinsic signal optical imaging, Doppler optical coherence tomography, and two-photon microscopy, we investigate how the progression of atherosclerotic disease affects the morphology and function of cortical microvasculature as well as baseline cerebral tissue oxygenation. Results show that aged ATX mice exhibited weaker hemodynamic response in the somatosensory cortex to whisker stimulation and that the diameter of their descending arterioles and associated mean blood flow decreased significantly compared with the young ATX group. Data from two-photon phosphorescence lifetime microscopy indicate that old ATX mice had lower and more heterogeneous partial pressure of oxygen ( PO 2 ) in cortical tissue than young ATX mice. In addition, hypoxic micropockets in cortical tissue were found in old, but not young, ATX mice. Capillary red blood cell (RBC) flux, RBC velocity, RBC velocity heterogeneity, hematocrit, and diameter were also measured using line scans with two-photon fluorescence microscopy. When compared with the young group, RBC flux, velocity, and hematocrit decreased and RBC velocity heterogeneity increased in old ATX mice, presumably due to disturbed blood supply from arterioles that were affected by atherosclerosis. Finally, dilation of capillaries in old ATX mice was observed, which suggests that capillaries play an active role in compensating for an oxygen deficit in brain tissue.
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Affiliation(s)
- Yuankang Lu
- École Polytechnique de Montréal, Laboratoire d’Imagerie optique et moléculaire, Montréal, Québec, Canada
| | - Cong Zhang
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
| | - Xuecong Lu
- École Polytechnique de Montréal, Laboratoire d’Imagerie optique et moléculaire, Montréal, Québec, Canada
| | - Mohammad Moeini
- Amirkabir University of Technology (Tehran Polytechnic), Biomedical Engineering Department, Tehran, Iran
| | - Eric Thorin
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
- Université de Montréal, Department of Pharmacology and Physiology, Faculty of Medicine, Montréal, Québec, Canada
| | - Frédéric Lesage
- École Polytechnique de Montréal, Laboratoire d’Imagerie optique et moléculaire, Montréal, Québec, Canada
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
- Address all correspondence to Frédéric Lesage, E-mail:
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Villabona-Rueda A, Erice C, Pardo CA, Stins MF. The Evolving Concept of the Blood Brain Barrier (BBB): From a Single Static Barrier to a Heterogeneous and Dynamic Relay Center. Front Cell Neurosci 2019; 13:405. [PMID: 31616251 PMCID: PMC6763697 DOI: 10.3389/fncel.2019.00405] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 08/23/2019] [Indexed: 12/27/2022] Open
Abstract
The blood–brain barrier (BBB) helps maintain a tightly regulated microenvironment for optimal central nervous system (CNS) homeostasis and facilitates communications with the peripheral circulation. The brain endothelial cells, lining the brain’s vasculature, maintain close interactions with surrounding brain cells, e.g., astrocytes, pericytes and perivascular macrophages. This function facilitates critical intercellular crosstalk, giving rise to the concept of the neurovascular unit (NVU). The steady and appropriate communication between all components of the NVU is essential for normal CNS homeostasis and function, and dysregulation of one of its constituents can result in disease. Among the different brain regions, and along the vascular tree, the cellular composition of the NVU varies. Therefore, differential cues from the immediate vascular environment can affect BBB phenotype. To support the fluctuating metabolic and functional needs of the underlying neuropil, a specialized vascular heterogeneity is required. This is achieved by variances in barrier function, expression of transporters, receptors, and adhesion molecules. This mini-review will take you on a journey through evolving concepts surrounding the BBB, the NVU and beyond. Exploring classical experiments leading to new approaches will allow us to understand that the BBB is not merely a static separation between the brain and periphery but a closely regulated and interactive entity. We will discuss shifting paradigms, and ultimately aim to address the importance of BBB endothelial heterogeneity with regard to the function of the BBB within the NVU, and touch on its implications for different neuropathologies.
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Affiliation(s)
- Andres Villabona-Rueda
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Clara Erice
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Carlos A Pardo
- Department of Neurology, Division of Neuroimmunology and Neuroinfectious Disorders, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Monique F Stins
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
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Unekawa M, Tomita Y, Toriumi H, Osada T, Masamoto K, Kawaguchi H, Izawa Y, Itoh Y, Kanno I, Suzuki N, Nakahara J. Spatiotemporal dynamics of red blood cells in capillaries in layer I of the cerebral cortex and changes in arterial diameter during cortical spreading depression and response to hypercapnia in anesthetized mice. Microcirculation 2019; 26:e12552. [PMID: 31050358 DOI: 10.1111/micc.12552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 04/21/2019] [Accepted: 04/29/2019] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Control of red blood cell velocity in capillaries is essential to meet local neuronal metabolic requirements, although changes of capillary diameter are limited. To further understand the microcirculatory response during cortical spreading depression, we analyzed the spatiotemporal changes of red blood cell velocity in intraparenchymal capillaries. METHODS In urethane-anesthetized Tie2-green fluorescent protein transgenic mice, the velocity of fluorescence-labeled red blood cells flowing in capillaries in layer I of the cerebral cortex was automatically measured with our Matlab domain software (KEIO-IS2) in sequential images obtained with a high-speed camera laser-scanning confocal fluorescence microscope system. RESULTS Cortical spreading depression repeatedly increased the red blood cell velocity prior to arterial constriction/dilation. During the first cortical spreading depression, red blood cell velocity significantly decreased, and sluggishly moving or retrograde-moving red blood cells were observed, concomitantly with marked arterial constriction. The velocity subsequently returned to around the basal level, while oligemia after cortical spreading depression with slight vasoconstriction remained. After several passages of cortical spreading depression, hypercapnia-induced increase of red blood cell velocity, regional cerebral blood flow and arterial diameter were all significantly reduced, and the correlations among them became extremely weak. CONCLUSIONS Taken together with our previous findings, these simultaneous measurements of red blood cell velocity in multiple capillaries, arterial diameter and regional cerebral blood flow support the idea that red blood cell flow might be altered independently, at least in part, from arterial regulation, that neuro-capillary coupling plays a role in rapidly meeting local neural demand.
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Affiliation(s)
- Miyuki Unekawa
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan.,Tomita Hospital, Okazaki, Japan
| | - Yutaka Tomita
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan.,Tomita Hospital, Okazaki, Japan
| | - Haruki Toriumi
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Takashi Osada
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuto Masamoto
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Chofu, Japan.,Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan
| | - Hiroshi Kawaguchi
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan.,Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Yoshikane Izawa
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Yoshiaki Itoh
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Iwao Kanno
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan
| | - Norihiro Suzuki
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan.,Department of Neurology, Shonan Keiiku Hospital, Fujisawa, Japan
| | - Jin Nakahara
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
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Binding Heterogeneity of Plasmodium falciparum to Engineered 3D Brain Microvessels Is Mediated by EPCR and ICAM-1. mBio 2019; 10:mBio.00420-19. [PMID: 31138740 PMCID: PMC6538777 DOI: 10.1128/mbio.00420-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cerebral malaria research has been hindered by the inaccessibility of the brain. Here, we have developed an engineered 3D human brain microvessel model that mimics the blood flow rates and architecture of small blood vessels to study how P. falciparum-infected human erythrocytes attach to brain endothelial cells. By studying parasite lines with different adhesive properties, we show that the malaria parasite binding rate is heterogeneous and strongly influenced by physiological differences in flow and whether the endothelium has been previously activated by TNF-α, a proinflammatory cytokine that is linked to malaria disease severity. We also show the importance of human EPCR and ICAM-1 in parasite binding. Our model sheds new light on how P. falciparum binds within brain microvessels and provides a powerful method for future investigations of recruitment of human brain pathogens to the blood vessel lining of the brain. Cerebral malaria is a severe neurological complication associated with sequestration of Plasmodium falciparum-infected erythrocytes (IE) in the brain microvasculature, but the specific binding interactions remain under debate. Here, we have generated an engineered three-dimensional (3D) human brain endothelial microvessel model and studied P. falciparum binding under the large range of physiological flow velocities that occur in both health and disease. Perfusion assays on 3D microvessels reveal previously unappreciated phenotypic heterogeneity in parasite binding to tumor necrosis factor alpha (TNF-α)-activated brain endothelial cells. While clonal parasite lines expressing a group B P. falciparum erythrocyte membrane protein 1 (PfEMP1) present an increase in binding to activated 3D microvessels, P. falciparum-IE expressing DC8-PfEMP1 present a decrease in binding. The differential response to endothelium activation is mediated by surface expression changes of endothelial protein C receptor (EPCR) and intercellular adhesion molecule 1 (ICAM-1). These findings demonstrate heterogeneity in parasite binding and provide evidence for a parasite strategy to adapt to a changing microvascular environment during infection. The engineered 3D human brain microvessel model provides new mechanistic insight into parasite binding and opens opportunities for further studies on malaria pathogenesis and parasite-vessel interactions.
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38
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Vendel E, Rottschäfer V, de Lange ECM. The need for mathematical modelling of spatial drug distribution within the brain. Fluids Barriers CNS 2019; 16:12. [PMID: 31092261 PMCID: PMC6521438 DOI: 10.1186/s12987-019-0133-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/19/2019] [Indexed: 12/17/2022] Open
Abstract
The blood brain barrier (BBB) is the main barrier that separates the blood from the brain. Because of the BBB, the drug concentration-time profile in the brain may be substantially different from that in the blood. Within the brain, the drug is subject to distributional and elimination processes: diffusion, bulk flow of the brain extracellular fluid (ECF), extra-intracellular exchange, bulk flow of the cerebrospinal fluid (CSF), binding and metabolism. Drug effects are driven by the concentration of a drug at the site of its target and by drug-target interactions. Therefore, a quantitative understanding is needed of the distribution of a drug within the brain in order to predict its effect. Mathematical models can help in the understanding of drug distribution within the brain. The aim of this review is to provide a comprehensive overview of system-specific and drug-specific properties that affect the local distribution of drugs in the brain and of currently existing mathematical models that describe local drug distribution within the brain. Furthermore, we provide an overview on which processes have been addressed in these models and which have not. Altogether, we conclude that there is a need for a more comprehensive and integrated model that fills the current gaps in predicting the local drug distribution within the brain.
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Affiliation(s)
- Esmée Vendel
- Mathematical Institute, Leiden University, Niels Bohrweg 1, 2333CA, Leiden, The Netherlands
| | - Vivi Rottschäfer
- Mathematical Institute, Leiden University, Niels Bohrweg 1, 2333CA, Leiden, The Netherlands
| | - Elizabeth C M de Lange
- Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333CC, Leiden, The Netherlands.
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Li L, Poloyac SM, Watkins SC, St. Croix CM, Alexander H, Gibson GA, Loughran PA, Kirisci L, Clark RSB, Kochanek PM, Vazquez AL, Manole MD. Cerebral microcirculatory alterations and the no-reflow phenomenon in vivo after experimental pediatric cardiac arrest. J Cereb Blood Flow Metab 2019; 39:913-925. [PMID: 29192562 PMCID: PMC6501505 DOI: 10.1177/0271678x17744717] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/29/2017] [Accepted: 10/25/2017] [Indexed: 01/02/2023]
Abstract
Decreased cerebral blood flow (CBF) after cardiac arrest (CA) contributes to secondary ischemic injury in infants and children. We previously reported cortical hypoperfusion with tissue hypoxia early in a pediatric rat model of asphyxial CA. In order to identify specific alterations as potential therapeutic targets to improve cortical hypoperfusion post-CA, we characterize the CBF alterations at the cortical microvascular level in vivo using multiphoton microscopy. We hypothesize that microvascular constriction and disturbances of capillary red blood cell (RBC) flow contribute to cortical hypoperfusion post-CA. After resuscitation from 9 min asphyxial CA, transient dilation of capillaries and venules at 5 min was followed by pial arteriolar constriction at 30 and 60 min (19.6 ± 1.3, 19.3 ± 1.2 µm at 30, 60 min vs. 22.0 ± 1.2 µm at baseline, p < 0.05). At the capillary level, microcirculatory disturbances were highly heterogeneous, with RBC stasis observed in 25.4% of capillaries at 30 min post-CA. Overall, the capillary plasma mean transit time was increased post-CA by 139.7 ± 51.5%, p < 0.05. In conclusion, pial arteriolar constriction, the no-reflow phenomenon and increased plasma transit time were observed post-CA. Our results detail the microvascular disturbances in a pediatric asphyxial CA model and provide a powerful platform for assessing specific vascular-targeted therapies.
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Affiliation(s)
- Lingjue Li
- Center of Clinical Pharmaceutical
Sciences,
University
of Pittsburgh, PA, USA
- School of Pharmacy,
University
of Pittsburgh, PA, USA
| | - Samuel M Poloyac
- Center of Clinical Pharmaceutical
Sciences,
University
of Pittsburgh, PA, USA
- School of Pharmacy,
University
of Pittsburgh, PA, USA
| | - Simon C Watkins
- Center for Biologic Imaging,
University
of Pittsburgh, PA, USA
| | | | - Henry Alexander
- Safar Center for Resuscitation Research,
University
of Pittsburgh, PA, USA
| | | | | | | | - Robert SB Clark
- Safar Center for Resuscitation Research,
University
of Pittsburgh, PA, USA
- Department of Critical Care Medicine,
University
of Pittsburgh, PA, USA
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research,
University
of Pittsburgh, PA, USA
- Department of Critical Care Medicine,
University
of Pittsburgh, PA, USA
- Department of Pediatrics,
University
of Pittsburgh, PA, USA
| | | | - Mioara D Manole
- Safar Center for Resuscitation Research,
University
of Pittsburgh, PA, USA
- Department of Critical Care Medicine,
University
of Pittsburgh, PA, USA
- Department of Pediatrics,
University
of Pittsburgh, PA, USA
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40
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Wang M, Wu N, Huang H, Luo J, Lan G, Zeng Y, Wang X, Xiong H, Han D, Tan H. Large-depth-of-field full-field optical angiography. JOURNAL OF BIOPHOTONICS 2019; 12:e201800329. [PMID: 30315638 DOI: 10.1002/jbio.201800329] [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: 08/29/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 06/08/2023]
Abstract
A large-depth-of-field full-field optical angiography (LD-FFOA) method is developed to expand the depth-of-field (DOF) using a contrast pyramid fusion algorithm (CPFA). The absorption intensity fluctuation modulation effect is utilized to obtain full-field optical angiography (FFOA) images at different focus positions. The CPFA is used to process these FFOA images with different focuses. By selecting high-contrast areas, the CPFA can highlight the characteristics and details of blood vessels to obtain LD-FFOA images. In the optimal case of the proposed method, the DOF for FFOA is more than tripled using 10 differently focused FFOA images. Both the phantom and animal experimental results show that the LD-FFOA resolves FFOA defocusing issues induced by surface and thickness inhomogeneities in biological samples. The proposed method can be potentially applied to practical biological experiments.
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Affiliation(s)
- Mingyi Wang
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Nanshou Wu
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Hongheng Huang
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Jiaxiong Luo
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Gongpu Lan
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Yaguang Zeng
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Xuehua Wang
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Honglian Xiong
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Dingan Han
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
| | - Haishu Tan
- School of Physics and Optoelectronic Engineering, Foshan University, Guangdong, China
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41
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Li M, Newton AT, Anderson AW, Ding Z, Gore JC. Characterization of the hemodynamic response function in white matter tracts for event-related fMRI. Nat Commun 2019; 10:1140. [PMID: 30850610 PMCID: PMC6408456 DOI: 10.1038/s41467-019-09076-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 02/12/2019] [Indexed: 01/02/2023] Open
Abstract
Accurate estimates of the BOLD hemodynamic response function (HRF) are crucial for the interpretation and analysis of event-related functional MRI data. To date, however, there have been no comprehensive measurements of the HRF in white matter (WM) despite increasing evidence that BOLD signals in WM change after a stimulus. We performed an event-related cognitive task (Stroop color-word interference) to measure the HRF in selected human WM pathways. The task was chosen in order to produce robust, distributed centers of activity throughout the cortex. To measure the HRF in WM, fiber tracts were reconstructed between each pair of activated cortical areas. We observed clear task-specific HRFs with reduced magnitudes, delayed onsets and prolonged initial dips in WM tracts compared with activated grey matter, thus calling for significant changes to current standard models for accurately characterizing the HRFs in WM and for modifications of standard methods of analysis of functional imaging data.
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Affiliation(s)
- Muwei Li
- Vanderbilt University Institute of Imaging Science, 1161 21st Ave. S, Medical Center North, AA-1105, Nashville, TN, 37232, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S, Medical Center North, Nashville, TN, 37232, USA
| | - Allen T Newton
- Vanderbilt University Institute of Imaging Science, 1161 21st Ave. S, Medical Center North, AA-1105, Nashville, TN, 37232, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S, Medical Center North, Nashville, TN, 37232, USA
| | - Adam W Anderson
- Vanderbilt University Institute of Imaging Science, 1161 21st Ave. S, Medical Center North, AA-1105, Nashville, TN, 37232, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S, Medical Center North, Nashville, TN, 37232, USA.,Department of Biomedical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN, 37235, USA
| | - Zhaohua Ding
- Vanderbilt University Institute of Imaging Science, 1161 21st Ave. S, Medical Center North, AA-1105, Nashville, TN, 37232, USA. .,Department of Biomedical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN, 37235, USA. .,Department of Electrical Engineering and Computer Science, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN, 37235, USA.
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, 1161 21st Ave. S, Medical Center North, AA-1105, Nashville, TN, 37232, USA. .,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S, Medical Center North, Nashville, TN, 37232, USA. .,Department of Biomedical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN, 37235, USA.
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42
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Bertrand L, Cho HJ, Toborek M. Blood-brain barrier pericytes as a target for HIV-1 infection. Brain 2019; 142:502-511. [PMID: 30668645 PMCID: PMC6391611 DOI: 10.1093/brain/awy339] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/19/2018] [Accepted: 11/06/2018] [Indexed: 12/11/2022] Open
Abstract
Pericytes are multifunctional cells wrapped around endothelial cells via cytoplasmic processes that extend along the abluminal surface of the endothelium. The interactions between endothelial cells and pericytes of the blood-brain barrier are necessary for proper formation, development, stabilization, and maintenance of the blood-brain barrier. Blood-brain barrier pericytes regulate paracellular flow between cells, transendothelial fluid transport, maintain optimal chemical composition of the surrounding microenvironment, and protect endothelial cells from potential harmful substances. Thus, dysfunction or loss of blood-brain barrier pericytes is an important factor in the pathogenesis of several diseases that are associated with microvascular instability. Importantly, recent research indicates that blood-brain barrier pericytes can be a target of HIV-1 infection able to support productive HIV-1 replication. In addition, blood-brain barrier pericytes are prone to establish a latent infection, which can be reactivated by a mixture of histone deacetylase inhibitors in combination with TNF. HIV-1 infection of blood-brain barrier pericytes has been confirmed in a mouse model of HIV-1 infection and in human post-mortem samples of HIV-1-infected brains. Overall, recent evidence indicates that blood-brain barrier pericytes can be a previously unrecognized HIV-1 target and reservoir in the brain.
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Affiliation(s)
- Luc Bertrand
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Hyung Joon Cho
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA,Correspondence to: Michal Toborek Department of Biochemistry and Molecular Biology University of Miami School of Medicine Gautier Bldg., Room 528 1011 NW 15th Street Miami, FL 33136, USA E-mail:
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43
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Juttukonda MR, Donahue MJ. Neuroimaging of vascular reserve in patients with cerebrovascular diseases. Neuroimage 2019; 187:192-208. [PMID: 29031532 PMCID: PMC5897191 DOI: 10.1016/j.neuroimage.2017.10.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/01/2017] [Accepted: 10/07/2017] [Indexed: 12/21/2022] Open
Abstract
Cerebrovascular reactivity, defined broadly as the ability of brain parenchyma to adjust cerebral blood flow in response to altered metabolic demand or a vasoactive stimulus, is being measured with increasing frequency and may have a use for portending new or recurrent stroke risk in patients with cerebrovascular disease. The purpose of this review is to outline (i) the physiological basis of variations in cerebrovascular reactivity, (ii) available approaches for measuring cerebrovascular reactivity in research and clinical settings, and (iii) clinically-relevant cerebrovascular reactivity findings in the context of patients with cerebrovascular disease, including atherosclerotic arterial steno-occlusion, non-atherosclerotic arterial steno-occlusion, anemia, and aging. Literature references summarizing safety considerations for these procedures and future directions for standardizing protocols and post-processing procedures across centers are presented in the specific context of major unmet needs in the setting of cerebrovascular disease.
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Affiliation(s)
- Meher R Juttukonda
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J Donahue
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, USA.
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44
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Zhao H, Sun P, Fan T, Yang X, Zheng T, Sun C. The effect of glutamate-induced excitotoxicity on DNA methylation in astrocytes in a new in vitro neuron-astrocyte-endothelium co-culture system. Biochem Biophys Res Commun 2018; 508:1209-1214. [PMID: 30558794 DOI: 10.1016/j.bbrc.2018.12.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 12/07/2018] [Indexed: 12/20/2022]
Abstract
Glutamate-induced excitotoxicity is a contributer to many neurological diseases. Astrocytes may represent a new target for treating glutamate-induced excitotoxicity. However, the in vitro culture system that mimics the in vivo microenvironment is lacking. This study aimed to establish a new in vitro co-culture system including neurons, astrocytes, and endothelial cells (NAE), and to investigate the effect of glutamate-induced excitotoxicity on DNA methylation in astrocytes. A NAE co-culture method was created using a Transwell chamber, in which neurons were seeded on the bottom of the lower chamber, endothelial cells were plated on the top membrane, and astrocytes were plated on the bottom membrane of the insert. Glutamate-induced toxicity was induced using glutamate and glycine, and examined using immunofluorescence and lactate dehydrogenase release assay. Global methylation in astrocytes was analyzed, and the expression of DNMT1 and DNMT3a was examined using Western blot analysis. Glutamate treatment induced less neuronal damage in the NAE system compared with the control group in which neurons and astrocytes were cultured alone. Global DNA methylation was increased and the expression of DNMT1 and DNMT3a in astrocytes was increased after glutamate treatment, which was blocked by application of the NMDAR inhibitor MK-801 and the DNMT inhibitor 5-azaC from the endothelial cells. The in vitro ANE culture system is effective for studying glutamate-induced excitotoxicity, and may be used for testing the passage of drugs across the blood-brain barrier. Inhibition of DNA methylation in astrocytes may be a new therapeutic strategy for treating glutamate-induced excitotoxicity.
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Affiliation(s)
- Hui Zhao
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Institute for Brain Disorders, Dalian Medical University, Dalian, 116044, China; Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, 116024, China; Research Center for the Control Engineering of Translational Precision Medicine, Dalian University of Technology, Dalian, 116024, China; State Key Laboratory of Fine Chemicals, Dalian R&D Center for Stem Cell and Tissue Engineering, Dalian University of Technology, Dalian, 116024, China
| | - Pin Sun
- Shanghai Medical College, Fudan University, Shanghai, 200000, China
| | - Tieping Fan
- Neurointerventional Department, Dalian Municipal Central Hospital Affiliated of Dalian Medical University, Dalian, 116024, China
| | - Xiaohan Yang
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Institute for Brain Disorders, Dalian Medical University, Dalian, 116044, China
| | - Tiezheng Zheng
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Institute for Brain Disorders, Dalian Medical University, Dalian, 116044, China
| | - Changkai Sun
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Institute for Brain Disorders, Dalian Medical University, Dalian, 116044, China; Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, 116024, China; Research Center for the Control Engineering of Translational Precision Medicine, Dalian University of Technology, Dalian, 116024, China; State Key Laboratory of Fine Chemicals, Dalian R&D Center for Stem Cell and Tissue Engineering, Dalian University of Technology, Dalian, 116024, China.
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45
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Tsai HC, Tsai CH, Chen WS, Inserra C, Wei KC, Liu HL. Safety evaluation of frequent application of microbubble-enhanced focused ultrasound blood-brain-barrier opening. Sci Rep 2018; 8:17720. [PMID: 30531863 PMCID: PMC6286368 DOI: 10.1038/s41598-018-35677-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 11/07/2018] [Indexed: 12/24/2022] Open
Abstract
Focused ultrasound (FUS) with the presence of microbubbles induces blood brain barrier (BBB) opening in targeted areas and facilitates drug delivery. However, recent studies have indicated that FUS-BBB opening with excessive exposure levels may be associated with inflammatory response and cellular/tissue damage. Multiple weekly FUS exposures have been shown to be safe for human subjects. However the effect of more frequent FUS exposures is still unknown. This study examines whether frequent focused ultrasound blood brain barrier opening is associated with aggravated behavioral, histopathologic change or brain tissue damage. Two protocols of focused ultrasound blood brain barrier opening were devised using different microbubble doses (0.15 µl/kg and 0.4 µl/kg). Focused ultrasound exposure at a threshold level of BBB-opening, below-threshold level, or above level for intracerebral hemorrhage were delivered every 2 days. Animal behavioral and physiological changes were examined and recorded. Brain tissue was examined for hemorrhage and apoptosis. Results indicate that frequent exposure of excessive focused ultrasound (1.4 mechanical index) produced minor and short-term behavioral changes despite significant tissue damage, while frequent BBB opening with threshold or below-threshold FUS exposure (0.33-0.8 mechanical index) did not cause behavioral or histological change. Immunofluorescent examination of rat brain tissue indicated that excessive doses of microbubble administration induce an apparent cellular apoptotic response, which may be exacerbated by intracerebral hemorrhage. Experimental results suggest that frequent focused ultrasound blood brain barrier opening with sufficient ultrasound exposure level and a microbubble dose can be safe and pose minimal risk to brain tissue.
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Affiliation(s)
- Hong-Chieh Tsai
- Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, 333, Taiwan.,Graduate Institute of Clinical Medical Sciences and School of Traditional Chinese Medicine, Chang Gung University, Taoyuan, 333, Taiwan
| | - Chih-Hung Tsai
- Department of Electrical Engineering, Chang-Gung University, Taoyuan, 333, Taiwan
| | - Wen-Shiang Chen
- Department of Physical Medicine & Rehabilitation, National Taiwan University Hospital, Taipei, 100, Taiwan
| | - Claude Inserra
- LabTAU, INSERM, Centre Léon Bérard, Université Lyon 1, Univ Lyon, Lyon, F-69003, France
| | - Kuo-Chen Wei
- Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, 333, Taiwan.
| | - Hao-Li Liu
- Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, 333, Taiwan. .,Department of Electrical Engineering, Chang-Gung University, Taoyuan, 333, Taiwan.
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46
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Masamoto K, Vazquez A. Optical imaging and modulation of neurovascular responses. J Cereb Blood Flow Metab 2018; 38:2057-2072. [PMID: 30334644 PMCID: PMC6282226 DOI: 10.1177/0271678x18803372] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/02/2018] [Indexed: 12/17/2022]
Abstract
The cerebral microvasculature consists of pial vascular networks, parenchymal descending arterioles, ascending venules and parenchymal capillaries. This vascular compartmentalization is vital to precisely deliver blood to balance continuously varying neural demands in multiple brain regions. Optical imaging techniques have facilitated the investigation of dynamic spatial and temporal properties of microvascular functions in real time. Their combination with transgenic animal models encoding specific genetic targets have further strengthened the importance of optical methods for neurovascular research by allowing for the modulation and monitoring of neuro vascular function. Image analysis methods with three-dimensional reconstruction are also helping to understand the complexity of microscopic observations. Here, we review the compartmentalized cerebral microvascular responses to global perturbations as well as regional changes in response to neural activity to highlight the differences in vascular action sites. In addition, microvascular responses elicited by optical modulation of different cell-type targets are summarized with emphasis on variable spatiotemporal dynamics of microvascular responses. Finally, long-term changes in microvascular compartmentalization are discussed to help understand potential relationships between CBF disturbances and the development of neurodegenerative diseases and cognitive decline.
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Affiliation(s)
- Kazuto Masamoto
- Faculty of Informatics and Engineering, University of Electro-Communications, Tokyo, Japan
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo, Japan
| | - Alberto Vazquez
- Departments of Radiology and Bioengineering, University of Pittsburgh, PA, USA
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47
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Maoz BM, Herland A, FitzGerald EA, Grevesse T, Vidoudez C, Pacheco AR, Sheehy SP, Park TE, Dauth S, Mannix R, Budnik N, Shores K, Cho A, Nawroth JC, Segrè D, Budnik B, Ingber DE, Parker KK. A linked organ-on-chip model of the human neurovascular unit reveals the metabolic coupling of endothelial and neuronal cells. Nat Biotechnol 2018; 36:865-874. [PMID: 30125269 PMCID: PMC9254231 DOI: 10.1038/nbt.4226] [Citation(s) in RCA: 269] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/20/2018] [Indexed: 12/30/2022]
Abstract
The neurovascular unit (NVU) regulates metabolic homeostasis as well as drug pharmacokinetics and pharmacodynamics in the central nervous system. Metabolic fluxes and conversions over the NVU rely on interactions between brain microvascular endothelium, perivascular pericytes, astrocytes and neurons, making it difficult to identify the contributions of each cell type. Here we model the human NVU using microfluidic organ chips, allowing analysis of the roles of individual cell types in NVU functions. Three coupled chips model influx across the blood-brain barrier (BBB), the brain parenchymal compartment and efflux across the BBB. We used this linked system to mimic the effect of intravascular administration of the psychoactive drug methamphetamine and to identify previously unknown metabolic coupling between the BBB and neurons. Thus, the NVU system offers an in vitro approach for probing transport, efficacy, mechanism of action and toxicity of neuroactive drugs.
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Affiliation(s)
- Ben M Maoz
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Anna Herland
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
- Department of Micro and Nanosystems, KTH Royal Institute of Technology, Stockholm, Sweden
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Edward A FitzGerald
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Thomas Grevesse
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Charles Vidoudez
- Small Molecule Mass Spectrometry Facility, Harvard University, Cambridge, Massachusetts, USA
| | - Alan R Pacheco
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
- Graduate Program in Bioinformatics and Biological Design Center, Boston University, Boston, Massachusetts, USA
| | - Sean P Sheehy
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Tae-Eun Park
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Stephanie Dauth
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Robert Mannix
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Nikita Budnik
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - Kevin Shores
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Alexander Cho
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Janna C Nawroth
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
| | - Daniel Segrè
- Graduate Program in Bioinformatics and Biological Design Center, Boston University, Boston, Massachusetts, USA
- Department of Biology, Department of Biomedical Engineering, Department of Physics, Boston University, Boston, Massachusetts, USA
| | - Bogdan Budnik
- Mass Spectrometry and Proteomics Resource Laboratory, Harvard University, Cambridge, Massachusetts, USA
| | - Donald E Ingber
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - Kevin Kit Parker
- Disease Biophysics Group, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
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48
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Germuska M, Wise RG. Calibrated fMRI for mapping absolute CMRO 2: Practicalities and prospects. Neuroimage 2018; 187:145-153. [PMID: 29605580 DOI: 10.1016/j.neuroimage.2018.03.068] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/14/2018] [Accepted: 03/28/2018] [Indexed: 01/21/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) is an essential workhorse of modern neuroscience, providing valuable insight into the functional organisation of the brain. The physiological mechanisms underlying the blood oxygenation level dependent (BOLD) effect are complex and preclude a straightforward interpretation of the signal. However, by employing appropriate calibration of the BOLD signal, quantitative measurements can be made of important physiological parameters including the absolute rate of cerebral metabolic oxygen consumption or oxygen metabolism (CMRO2) and oxygen extraction (OEF). The ability to map such fundamental parameters has the potential to greatly expand the utility of fMRI and to broaden its scope of application in clinical research and clinical practice. In this review article we discuss some of the practical issues related to the calibrated-fMRI approach to the measurement of CMRO2. We give an overview of the necessary precautions to ensure high quality data acquisition, and explore some of the pitfalls and challenges that must be considered as it is applied and interpreted in a widening array of diseases and research questions.
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Affiliation(s)
- M Germuska
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, CF24 4HQ, Cardiff, UK
| | - R G Wise
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, CF24 4HQ, Cardiff, UK.
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49
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Guerra G, Lucariello A, Perna A, Botta L, De Luca A, Moccia F. The Role of Endothelial Ca 2+ Signaling in Neurovascular Coupling: A View from the Lumen. Int J Mol Sci 2018; 19:E938. [PMID: 29561829 PMCID: PMC5979341 DOI: 10.3390/ijms19040938] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Neurovascular coupling (NVC) is the mechanism whereby an increase in neuronal activity (NA) leads to local elevation in cerebral blood flow (CBF) to match the metabolic requirements of firing neurons. Following synaptic activity, an increase in neuronal and/or astrocyte Ca2+ concentration leads to the synthesis of multiple vasoactive messengers. Curiously, the role of endothelial Ca2+ signaling in NVC has been rather neglected, although endothelial cells are known to control the vascular tone in a Ca2+-dependent manner throughout peripheral vasculature. METHODS We analyzed the literature in search of the most recent updates on the potential role of endothelial Ca2+ signaling in NVC. RESULTS We found that several neurotransmitters (i.e., glutamate and acetylcholine) and neuromodulators (e.g., ATP) can induce dilation of cerebral vessels by inducing an increase in endothelial Ca2+ concentration. This, in turn, results in nitric oxide or prostaglandin E2 release or activate intermediate and small-conductance Ca2+-activated K⁺ channels, which are responsible for endothelial-dependent hyperpolarization (EDH). In addition, brain endothelial cells express multiple transient receptor potential (TRP) channels (i.e., TRPC3, TRPV3, TRPV4, TRPA1), which induce vasodilation by activating EDH. CONCLUSIONS It is possible to conclude that endothelial Ca2+ signaling is an emerging pathway in the control of NVC.
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Affiliation(s)
- Germano Guerra
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, via F. De Santis, 86100 Campobasso, Italy.
| | - Angela Lucariello
- Department of Mental Health and Preventive Medicine, Section of Human Anatomy, University of Campania "L. Vanvitelli", 81100 Naples, Italy.
| | - Angelica Perna
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, via F. De Santis, 86100 Campobasso, Italy.
| | - Laura Botta
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Forlanini 6, 27100 Pavia, Italy.
| | - Antonio De Luca
- Department of Mental Health and Preventive Medicine, Section of Human Anatomy, University of Campania "L. Vanvitelli", 81100 Naples, Italy.
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Forlanini 6, 27100 Pavia, Italy.
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50
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Bakken GS, Schraft HA, Cattell RW, Tiu DB, Clark RW. Cooler snakes respond more strongly to infrared stimuli, but we have no idea why. J Exp Biol 2018; 221:jeb.182121. [DOI: 10.1242/jeb.182121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/02/2018] [Indexed: 11/20/2022]
Abstract
The pit organ defining pit vipers (Crotalinae) contains a membrane covered with temperature receptors that detect thermal radiation from environmental surfaces. Temperature is both the environmental parameter being sensed and the mechanism by which the pit membrane detects the signal. As snakes are ectotherms, temperature also has a strong influence on neurological and locomotor responses to the signal. This study of Pacific Rattlesnakes (Crotalus oreganus) systematically examined the effect of body, target, and background temperatures on response to a moving target. We presented each snake with a moving pendulum bob regulated at a series of 6 temperatures against a uniform background regulated at one of 3 temperatures. Snake body temperatures varied from 18° to 36°C. As expected, we found stronger responses to positive contrasts (target warmer than background) than to negative contrasts, and stronger responses to greater contrasts. However, the effect of body temperature was contrary to expectations based on studies of the TRPA1 ion channel (believed to be the molecular basis for pit membrane temperature receptors) and typical thermal reaction norms for neural and motor performance. These predict (1) no response below the threshold where the TRPA1 channel opens, (2) response increasing as temperature increases, peaking near preferred body temperature, and (3) declining thereafter. Remarkably, this behavioral response decreased as body temperature increased from 18°C to 36°C, with no threshold or peak in this range. We review various possible physiological mechanisms related to body temperature proposed in the literature, but find none that can satisfactorily explain this result.
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Affiliation(s)
- George S. Bakken
- 4431 East Park Ave, Terre Haute, IN, USA
- Biology Department, San Diego State University, San Diego, CA, USA
| | - Hannes A. Schraft
- Biology Department, San Diego State University, San Diego, CA, USA
- Graduate Group in Ecology, University of California, Davis, CA, USA
| | | | - Donna B. Tiu
- Biology Department, San Diego State University, San Diego, CA, USA
| | - Rulon W. Clark
- Biology Department, San Diego State University, San Diego, CA, USA
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