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Stamenkovic S, Schmid F, Weitermann N, Takasaki K, Bonney SK, Sosa MJ, Li Y, Bennett HC, Kim Y, Waters J, Shih AY. Impaired drainage through capillary-venous networks contributes to age-related white matter loss. bioRxiv 2024:2024.02.11.579849. [PMID: 38405879 PMCID: PMC10888936 DOI: 10.1101/2024.02.11.579849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
The gradual loss of cerebral white matter contributes to cognitive decline during aging. However, microvascular networks that support the metabolic demands of white matter remain poorly defined. We used in vivo deep multi-photon imaging to characterize microvascular networks that perfuse cortical layer 6 and corpus callosum, a highly studied region of white matter in the mouse brain. We show that these deep tissues are exclusively drained by sparse and wide-reaching venules, termed principal cortical venules, which mirror vascular architecture at the human cortical-U fiber interface. During aging, capillary networks draining into deep branches of principal cortical venules are selectively constricted, reduced in density, and diminished in pericyte numbers. This causes hypo-perfusion in deep tissues, and correlates with gliosis and demyelination, whereas superficial tissues become relatively hyper-perfused. Thus, age-related impairment of capillary-venular drainage is a key vascular deficit that contributes to the unique vulnerability of cerebral white matter during brain aging.
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2
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Bonney SK, Nielson CD, Sosa MJ, Shih AY. Capillary regression leads to sustained local hypoperfusion by inducing constriction of upstream transitional vessels. bioRxiv 2023:2023.10.28.564529. [PMID: 37961686 PMCID: PMC10635020 DOI: 10.1101/2023.10.28.564529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In the brain, a microvascular sensory web coordinates oxygen delivery to regions of neuronal activity. This involves a dense network of capillaries that send conductive signals upstream to feeding arterioles to promote vasodilation and blood flow. Although this process is critical to the metabolic supply of healthy brain tissue, it may also be a point of vulnerability in disease. Deterioration of capillary networks is a hallmark of many neurological disorders and how this web is engaged during vascular damage remains unknown. We performed in vivo two-photon microscopy on young adult mural cell reporter mice and induced focal capillary injuries using precise two-photon laser irradiation of single capillaries. We found that ∼63% of the injuries resulted in regression of the capillary segment 7-14 days following injury, and the remaining repaired to re-establish blood flow within 7 days. Injuries that resulted in capillary regression induced sustained vasoconstriction in the upstream arteriole-capillary transition (ACT) zone at least 21 days post-injury in both awake and anesthetized mice. This abnormal vasoconstriction involved attenuation of vasomotor dynamics and uncoupling from mural cell calcium signaling following capillary regression. Consequently, blood flow was reduced in the ACT zone and in secondary, uninjured downstream capillaries. These findings demonstrate how capillary injury and regression, as often seen in age-related neurological disease, can impair the microvascular sensory web and contribute to cerebral hypoperfusion. SIGNIFICANCE Deterioration of the capillary network is a characteristic of many neurological diseases and can exacerbate neuronal dysfunction and degeneration due to poor blood perfusion. Here we show that focal capillary injuries can induce vessel regression and elicit sustained vasoconstriction in upstream transitional vessels that branch from cortical penetrating arterioles. This reduces blood flow to broader, uninjured regions of the same microvascular network. These findings suggest that widespread and cumulative damage to brain capillaries in neurological disease may broadly affect blood supply and contribute to hypoperfusion through their remote actions.
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Sosa MJ, Shih AY, Bonney SK. The elusive brain perivascular fibroblast: a potential role in vascular stability and homeostasis. Front Cardiovasc Med 2023; 10:1283434. [PMID: 38075961 PMCID: PMC10704358 DOI: 10.3389/fcvm.2023.1283434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 11/10/2023] [Indexed: 01/09/2024] Open
Abstract
In the brain, perivascular fibroblasts (PVFs) reside within the perivascular spaces (PVSs) of arterioles and large venules, however their physiological and pathophysiological roles remain largely unknown. PVFs express numerous extracellular matrix proteins that are found in the basement membrane and PVS surrounding large diameter vessels. PVFs are sandwiched between the mural cell layer and astrocytic endfeet, where they are poised to interact with mural cells, perivascular macrophages, and astrocytes. We draw connections between the more well-studied PVF pro-fibrotic response in ischemic injury and the less understood thickening of the vascular wall and enlargement of the PVS described in dementia and neurodegenerative diseases. We postulate that PVFs may be responsible for stability and homeostasis of the brain vasculature, and may also contribute to changes within the PVS during disease.
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Affiliation(s)
- Maria J. Sosa
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington, Seattle, WA, United States
- Department of Bioengineering, University of Washington, Seattle, WA, United States
| | - Stephanie K. Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
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4
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Jones HE, Coelho-Santos V, Bonney SK, Abrams KA, Shih AY, Siegenthaler JA. Meningeal origins and dynamics of perivascular fibroblast development on the mouse cerebral vasculature. Development 2023; 150:dev201805. [PMID: 37756588 PMCID: PMC10565218 DOI: 10.1242/dev.201805] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023]
Abstract
Perivascular fibroblasts (PVFs) are a fibroblast-like cell type that reside on large-diameter blood vessels in the adult meninges and central nervous system (CNS). PVFs contribute to fibrosis following injury but their homeostatic functions are not defined. PVFs were previously shown to be absent from most brain regions at birth and are only detected postnatally within the cerebral cortex. However, the origin, timing and cellular mechanisms of PVF development are not known. We used Col1a1-GFP and Col1a2-CreERT2 transgenic mice to track PVF development postnatally. Using lineage tracing and in vivo imaging we show that brain PVFs originate from the meninges and are first seen on parenchymal cerebrovasculature at postnatal day (P) 5. After P5, PVF coverage of the cerebrovasculature expands via local cell proliferation and migration from the meninges. Finally, we show that PVFs and perivascular macrophages develop concurrently. These findings provide the first complete timeline for PVF development in the brain, enabling future work into how PVF development is coordinated with cell types and structures in and around the perivascular spaces to support normal CNS vascular function.
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Affiliation(s)
- Hannah E. Jones
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Aurora, CO 80045, USA
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado, Aurora, CO 80045, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA 98101, USA
| | - Stephanie K. Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA 98101, USA
| | - Kelsey A. Abrams
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Aurora, CO 80045, USA
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado, Aurora, CO 80045, USA
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA 98101, USA
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- Department of Pediatrics, University of Washington, Seattle, WA 98105, USA
| | - Julie A. Siegenthaler
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Aurora, CO 80045, USA
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado, Aurora, CO 80045, USA
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5
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Severs LJ, Bush NE, Quina LA, Hidalgo-Andrade S, Burgraff NJ, Dashevskiy T, Shih AY, Baertsch NA, Ramirez JM. Purinergic signaling mediates neuroglial interactions to modulate sighs. Nat Commun 2023; 14:5300. [PMID: 37652903 PMCID: PMC10471608 DOI: 10.1038/s41467-023-40812-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 08/10/2023] [Indexed: 09/02/2023] Open
Abstract
Sighs prevent the collapse of alveoli in the lungs, initiate arousal under hypoxic conditions, and are an expression of sadness and relief. Sighs are periodically superimposed on normal breaths, known as eupnea. Implicated in the generation of these rhythmic behaviors is the preBötzinger complex (preBötC). Our experimental evidence suggests that purinergic signaling is necessary to generate spontaneous and hypoxia-induced sighs in a mouse model. Our results demonstrate that driving calcium increases in astrocytes through pharmacological methods robustly increases sigh, but not eupnea, frequency. Calcium imaging of preBötC slices corroborates this finding with an increase in astrocytic calcium upon application of sigh modulators, increasing intracellular calcium through g-protein signaling. Moreover, photo-activation of preBötC astrocytes is sufficient to elicit sigh activity, and this response is blocked with purinergic antagonists. We conclude that sighs are modulated through neuron-glia coupling in the preBötC network, where the distinct modulatory responses of neurons and glia allow for both rhythms to be independently regulated.
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Affiliation(s)
- Liza J Severs
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA.
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195, USA.
| | - Nicholas E Bush
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Lely A Quina
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Skyler Hidalgo-Andrade
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Nicholas J Burgraff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Tatiana Dashevskiy
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, 98195, USA
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
| | - Nathan A Baertsch
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA.
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195, USA.
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, 98195, USA.
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, 98195, USA.
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Ighodaro ET, Shahidehpour RK, Bachstetter AD, Abner EL, Nelson RS, Fardo DW, Shih AY, Grant RI, Neltner JH, Schmitt FA, Jicha GA, Kryscio RJ, Wilcock DM, Van Eldik LJ, Nelson PT. A neuropathologic feature of brain aging: multi-lumen vascular profiles. Acta Neuropathol Commun 2023; 11:138. [PMID: 37641147 PMCID: PMC10464008 DOI: 10.1186/s40478-023-01638-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/13/2023] [Indexed: 08/31/2023] Open
Abstract
Cerebrovascular pathologies other than frank infarctions are commonly seen in aged brains. Here, we focus on multi-lumen vascular profiles (MVPs), which are characterized by multiple vessel lumens enclosed in a single vascular channel. Little information exists on the prevalence, risk factors, and co-pathologies of MVPs. Therefore, we used samples and data from the University of Kentucky Alzheimer's Disease Research Center (n = 91), the University of Kentucky Pathology Department (n = 31), and the University of Pittsburgh Pathology Department (n = 4) to study MVPs. Age at death was correlated with MVP density in the frontal neocortex, Brodmann Area 9 (r = 0.51; p < 0.0001). Exploratory analyses were performed to evaluate the association between conventional vascular risk factors (e.g., hypertension, diabetes), cardiovascular diseases (e.g., heart attack, arrhythmia), and cerebrovascular disease (e.g., stroke); the only nominal association with MVP density was a self-reported history of brain trauma (Prevalence Ratio = 2.1; 95 CI 1.1-3.9, before correcting for multiple comparisons). No specific associations were detected between neuropathological (e.g., brain arteriolosclerosis) or genetic (e.g., APOE) variables and MVP density. Using a tissue clearing method called SeeDB, we provide 3-dimensional images of MVPs in brain tissue. We conclude that MVPs are an age-related brain pathology and more work is required to identify their clinical-pathological correlation and associated risk factors.
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Affiliation(s)
- Eseosa T Ighodaro
- Department of Neurology, Emory University, Atlanta, GA, USA
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
| | - Ryan K Shahidehpour
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, 40536, USA
| | - Adam D Bachstetter
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, 40536, USA
| | - Erin L Abner
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Epidemiology and Environmental Health, University of Kentucky, Lexington, KY, 40536, USA
| | | | - David W Fardo
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Biostatistics, University of Kentucky, Lexington, KY, 40536, USA
| | - Andy Y Shih
- Department of Pediatrics, Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, University of Washington, Seattle, WA, 98101, USA
| | - Roger I Grant
- Department of Neurosciences and Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Janna H Neltner
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, University of Kentucky, Lexington, KY, 40536, USA
| | - Frederick A Schmitt
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Neurology, University of Kentucky, Lexington, KY, 40536, USA
| | - Gregory A Jicha
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Neurology, University of Kentucky, Lexington, KY, 40536, USA
| | - Richard J Kryscio
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Statistics, University of Kentucky, Lexington, KY, 40536, USA
- Department of Biostatistics, University of Kentucky, Lexington, KY, 40536, USA
| | - Donna M Wilcock
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
| | - Linda J Van Eldik
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
| | - Peter T Nelson
- Sanders-Brown Center On Aging, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA.
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA.
- Department of Pathology and Laboratory Medicine, Division of Neuropathology, University of Kentucky, Lexington, KY, 40536, USA.
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Iadecola C, Smith EE, Anrather J, Gu C, Mishra A, Misra S, Perez-Pinzon MA, Shih AY, Sorond FA, van Veluw SJ, Wellington CL. The Neurovasculome: Key Roles in Brain Health and Cognitive Impairment: A Scientific Statement From the American Heart Association/American Stroke Association. Stroke 2023; 54:e251-e271. [PMID: 37009740 PMCID: PMC10228567 DOI: 10.1161/str.0000000000000431] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
Abstract
BACKGROUND Preservation of brain health has emerged as a leading public health priority for the aging world population. Advances in neurovascular biology have revealed an intricate relationship among brain cells, meninges, and the hematic and lymphatic vasculature (the neurovasculome) that is highly relevant to the maintenance of cognitive function. In this scientific statement, a multidisciplinary team of experts examines these advances, assesses their relevance to brain health and disease, identifies knowledge gaps, and provides future directions. METHODS Authors with relevant expertise were selected in accordance with the American Heart Association conflict-of-interest management policy. They were assigned topics pertaining to their areas of expertise, reviewed the literature, and summarized the available data. RESULTS The neurovasculome, composed of extracranial, intracranial, and meningeal vessels, as well as lymphatics and associated cells, subserves critical homeostatic functions vital for brain health. These include delivering O2 and nutrients through blood flow and regulating immune trafficking, as well as clearing pathogenic proteins through perivascular spaces and dural lymphatics. Single-cell omics technologies have unveiled an unprecedented molecular heterogeneity in the cellular components of the neurovasculome and have identified novel reciprocal interactions with brain cells. The evidence suggests a previously unappreciated diversity of the pathogenic mechanisms by which disruption of the neurovasculome contributes to cognitive dysfunction in neurovascular and neurodegenerative diseases, providing new opportunities for the prevention, recognition, and treatment of these conditions. CONCLUSIONS These advances shed new light on the symbiotic relationship between the brain and its vessels and promise to provide new diagnostic and therapeutic approaches for brain disorders associated with cognitive dysfunction.
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Coelho-Santos V, Cruz AJN, Shih AY. Does Perinatal Intermittent Hypoxia Affect Cerebrovascular Network Development? Dev Neurosci 2023; 46:44-54. [PMID: 37231864 DOI: 10.1159/000530957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023] Open
Abstract
Perinatal hypoxia is an inadequate delivery of oxygen to the fetus in the period immediately before, during, or after the birth process. The most frequent form of hypoxia occurring in human development is chronic intermittent hypoxia (CIH) due to sleep-disordered breathing (apnea) or bradycardia events. CIH incidence is particularly high with premature infants. During CIH, repetitive cycles of hypoxia and reoxygenation initiate oxidative stress and inflammatory cascades in the brain. A dense microvascular network of arterioles, capillaries, and venules is required to support the constant metabolic demands of the adult brain. The development and refinement of this microvasculature is orchestrated throughout gestation and in the initial weeks after birth, at a critical juncture when CIH can occur. There is little knowledge on how CIH affects the development of the cerebrovasculature. However, since CIH (and its treatments) can cause profound abnormalities in tissue oxygen content and neural activity, there is reason to believe that it can induce lasting abnormalities in vascular structure and function at the microvascular level contributing to neurodevelopmental disorders. This mini-review discusses the hypothesis that CIH induces a positive feedback loop to perpetuate metabolic insufficiency through derailment of normal cerebrovascular development, leading to long-term deficiencies in cerebrovascular function.
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Affiliation(s)
- Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, Coimbra, Portugal
| | - Anne-Jolene N Cruz
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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9
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Sargent SM, Bonney SK, Li Y, Stamenkovic S, Takeno M, Coelho-Santos V, Shih AY. Endothelial structure contributes to heterogeneity in brain capillary diameter. bioRxiv 2023:2023.04.26.538503. [PMID: 37163126 PMCID: PMC10168366 DOI: 10.1101/2023.04.26.538503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The high metabolic demand of brain tissue is supported by a constant supply of blood through dense microvascular networks. Capillaries are the smallest class of vessels and vary in diameter between ∼2 to 5 μm in the brain. This diameter range plays a significant role in the optimization of blood flow resistance, blood cell distribution, and oxygen extraction. The control of capillary diameter has largely been ascribed to pericyte contractility, but it remains unclear if endothelial wall architecture also contributes to capillary diameter heterogeneity. Here, we use public, large-scale volume electron microscopy data from mouse cortex (MICrONS Explorer, Cortical MM^3) to examine how endothelial cell number, endothelial cell thickness, and pericyte coverage relates to microvascular lumen size. We find that transitional vessels near the penetrating arteriole and ascending venule are composed of 2 to 5 interlocked endothelial cells, while the numerous capillary segments intervening these zones are composed of either 1 or 2 endothelial cells, with roughly equal proportions. The luminal area and diameter is on average slightly larger with capillary segments composed of 2 interlocked endothelial cells versus 1 endothelial cell. However, this difference is insufficient to explain the full range of capillary diameters seen in vivo. This suggests that both endothelial structure and other influences, such as pericyte tone, contribute to the basal diameter and optimized perfusion of brain capillaries.
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10
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Jones HE, Coelho-Santos V, Bonney SK, Abrams KA, Shih AY, Siegenthaler JA. Meningeal origins and dynamics of perivascular fibroblast development on the mouse cerebral vasculature. bioRxiv 2023:2023.03.23.533982. [PMID: 36993587 PMCID: PMC10055392 DOI: 10.1101/2023.03.23.533982] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Perivascular fibroblasts (PVFs) are a fibroblast-like cell type that reside on large-diameter blood vessels in the adult meninges and central nervous system (CNS). PVFs drive fibrosis following injury but their homeostatic functions are not well detailed. In mice, PVFs were previously shown to be absent from most brain regions at birth and are only detected postnatally within the cerebral cortex. However, the origin, timing, and cellular mechanisms of PVF development are not known. We used Col1a1-GFP and Col1a2-CreERT transgenic mice to track PVF developmental timing and progression in postnatal mice. Using a combination of lineage tracing and in vivo imaging we show that brain PVFs originate from the meninges and are first seen on parenchymal cerebrovasculature at postnatal day (P)5. After P5, PVF coverage of the cerebrovasculature rapidly expands via mechanisms of local cell proliferation and migration from the meninges, reaching adult levels at P14. Finally, we show that PVFs and perivascular macrophages (PVMs) develop concurrently along postnatal cerebral blood vessels, where the location and depth of PVMs and PVFs highly correlate. These findings provide the first complete timeline for PVF development in the brain, enabling future work into how PVF development is coordinated with cell types and structures in and around the perivascular spaces to support normal CNS vascular function. Summary Brain perivascular fibroblasts migrate from their origin in the meninges and proliferate locally to fully cover penetrating vessels during postnatal mouse development.
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11
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Sargent SM, Bonney SK, Li Y, Stamenkovic S, Takeno MM, Coelho-Santos V, Shih AY. Endothelial structure contributes to heterogeneity in brain capillary diameter. Vasc Biol 2023; 5:e230010. [PMID: 37582180 PMCID: PMC10503221 DOI: 10.1530/vb-23-0010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 08/15/2023] [Indexed: 08/17/2023]
Abstract
The high metabolic demand of brain tissue is supported by a constant supply of blood flow through dense microvascular networks. Capillaries are the smallest class of vessels in the brain and their lumens vary in diameter between ~2 and 5 μm. This diameter range plays a significant role in optimizing blood flow resistance, blood cell distribution, and oxygen extraction. The control of capillary diameter has largely been ascribed to pericyte contractility, but it remains unclear if the architecture of the endothelial wall also contributes to capillary diameter. Here, we use public, large-scale volume electron microscopy data from mouse cortex (MICrONS Explorer, Cortical mm3) to examine how endothelial cell number, endothelial cell thickness, and pericyte coverage relates to microvascular lumen size. We find that transitional vessels near the penetrating arteriole and ascending venule are composed of two to six interlocked endothelial cells, while the capillaries intervening these zones are composed of either one or two endothelial cells, with roughly equal proportions. The luminal area and diameter are on average slightly larger with capillary segments composed of two interlocked endothelial cells vs one endothelial cell. However, this difference is insufficient to explain the full range of capillary diameters seen in vivo. This suggests that both endothelial structure and other influences, including pericyte tone, contribute to the basal diameter and optimized perfusion of brain capillaries.
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Affiliation(s)
- Sheridan M Sargent
- Neuroscience Graduate Program, University of Washington, Seattle, Washington, USA
| | - Stephanie K Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Yuandong Li
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Stefan Stamenkovic
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Marc M Takeno
- Allen Institute for Brain Science, Seattle, Washington, USA
| | - Vanessa Coelho-Santos
- Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Portugal
- Institute of Nuclear Sciences Applied to Health, University of Coimbra, Portugal
| | - Andy Y Shih
- Neuroscience Graduate Program, University of Washington, Seattle, Washington, USA
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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12
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Calabrese B, Jones SL, Shiraishi-Yamaguchi Y, Lingelbach M, Manor U, Svitkina TM, Higgs HN, Shih AY, Halpain S. INF2-mediated actin filament reorganization confers intrinsic resilience to neuronal ischemic injury. Nat Commun 2022; 13:6037. [PMID: 36229429 PMCID: PMC9558009 DOI: 10.1038/s41467-022-33268-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 09/09/2022] [Indexed: 12/24/2022] Open
Abstract
During early ischemic brain injury, glutamate receptor hyperactivation mediates neuronal death via osmotic cell swelling. Here we show that ischemia and excess NMDA receptor activation cause actin to rapidly and extensively reorganize within the somatodendritic compartment. Normally, F-actin is concentrated within dendritic spines. However, <5 min after bath-applied NMDA, F-actin depolymerizes within spines and polymerizes into stable filaments within the dendrite shaft and soma. A similar actinification occurs after experimental ischemia in culture, and photothrombotic stroke in mouse. Following transient NMDA incubation, actinification spontaneously reverses. Na+, Cl-, water, and Ca2+ influx, and spine F-actin depolymerization are all necessary, but not individually sufficient, for actinification, but combined they induce activation of the F-actin polymerization factor inverted formin-2 (INF2). Silencing of INF2 renders neurons vulnerable to cell death and INF2 overexpression is protective. Ischemia-induced dendritic actin reorganization is therefore an intrinsic pro-survival response that protects neurons from death induced by cell edema.
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Affiliation(s)
- Barbara Calabrese
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, and Sanford Consortium for Regenerative Medicine, La Jolla, CA, 92093, USA
| | - Steven L Jones
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104-4544, USA
| | | | - Michael Lingelbach
- Neurosciences Interdepartmental Program, Stanford University, Stanford, CA, 94305, USA
| | - Uri Manor
- The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Tatyana M Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104-4544, USA
| | - Henry N Higgs
- Department of Biochemistry, Geisel School of Medicine, Hanover, NH, 03755, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Shelley Halpain
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, and Sanford Consortium for Regenerative Medicine, La Jolla, CA, 92093, USA.
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13
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Berthiaume AA, Schmid F, Stamenkovic S, Coelho-Santos V, Nielson CD, Weber B, Majesky MW, Shih AY. Pericyte remodeling is deficient in the aged brain and contributes to impaired capillary flow and structure. Nat Commun 2022; 13:5912. [PMID: 36207315 PMCID: PMC9547063 DOI: 10.1038/s41467-022-33464-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/14/2022] [Indexed: 02/06/2023] Open
Abstract
Deterioration of brain capillary flow and architecture is a hallmark of aging and dementia. It remains unclear how loss of brain pericytes in these conditions contributes to capillary dysfunction. Here, we conduct cause-and-effect studies by optically ablating pericytes in adult and aged mice in vivo. Focal pericyte loss induces capillary dilation without blood-brain barrier disruption. These abnormal dilations are exacerbated in the aged brain, and result in increased flow heterogeneity in capillary networks. A subset of affected capillaries experience reduced perfusion due to flow steal. Some capillaries stall in flow and regress, leading to loss of capillary connectivity. Remodeling of neighboring pericytes restores endothelial coverage and vascular tone within days. Pericyte remodeling is slower in the aged brain, resulting in regions of persistent capillary dilation. These findings link pericyte loss to disruption of capillary flow and structure. They also identify pericyte remodeling as a therapeutic target to preserve capillary flow dynamics.
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Affiliation(s)
- Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Franca Schmid
- Institute of Fluid Dynamics, ETH Zurich, Sonneggstrasse 3, Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Stefan Stamenkovic
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Cara D Nielson
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Mark W Majesky
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA.
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
- Department of Pediatrics, University of Washington, Seattle, WA, USA.
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
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14
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Abstract
Modulation of brain arteriole diameter is critical for maintaining cerebral blood pressure and controlling regional hyperemia during neural activity. However, studies of hemodynamic function in health and disease have lacked a method to control arteriole diameter independently with high spatiotemporal resolution. Here, we describe an all-optical approach to manipulate and monitor brain arteriole contractility in mice in three dimensions using combined in vivo two-photon optogenetics and imaging. The expression of the red-shifted excitatory opsin, ReaChR, in vascular smooth muscle cells enabled rapid and repeated vasoconstriction controlled by brief light pulses. Two-photon activation of ReaChR using a spatial light modulator produced highly localized constrictions when targeted to individual arterioles within the neocortex. We demonstrate the utility of this method for examining arteriole contractile dynamics and creating transient focal blood flow reductions. Additionally, we show that optogenetic constriction can be used to reshape vasodilatory responses to sensory stimulation, providing a valuable tool to dissociate blood flow changes from neural activity.
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Affiliation(s)
- Philip J O'Herron
- Department of Physiology, Augusta University
- Department of Neuroscience, Medical University of South Carolina
| | - David A Hartmann
- Department of Neuroscience, Medical University of South Carolina
- Department of Neurology & Neurological Sciences, Stanford University
| | - Kun Xie
- Department of Physiology, Augusta University
| | - Prakash Kara
- Department of Neuroscience, Medical University of South Carolina
- Department of Neuroscience, University of Minnesota
- Center for Magnetic Resonance Research, University of Minnesota
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute
- Department of Bioengineering, University of Washington
- Department of Pediatrics, University of Washington
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15
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Nielson CD, Berthiaume AA, Bonney SK, Shih AY. Corrigendum: In vivo Single Cell Optical Ablation of Brain Pericytes. Front Neurosci 2022; 16:974311. [PMID: 35911985 PMCID: PMC9326768 DOI: 10.3389/fnins.2022.974311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Cara D. Nielson
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Stephanie K. Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington, Seattle, WA, United States
- Department of Bioengineering, University of Washington, Seattle, WA, United States
- *Correspondence: Andy Y. Shih
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16
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Coelho-Santos V, Tieu T, Shih AY. Reinforced thinned-skull window for repeated imaging of the neonatal mouse brain. Neurophotonics 2022; 9:031918. [PMID: 35673538 PMCID: PMC9163199 DOI: 10.1117/1.nph.9.3.031918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/03/2022] [Indexed: 06/15/2023]
Abstract
Significance: Two-photon microscopy is a powerful tool for in vivo imaging of the mammalian brain at cellular to subcellular resolution. However, resources that describe methods for imaging live newborn mice have remained sparse. Aim: We describe a non-invasive cranial window procedure for longitudinal imaging of neonatal mice. Approach: We demonstrate construction of the cranial window by iterative shaving of the calvarium of P0 to P12 mouse pups. We use the edge of a syringe needle and scalpel blades to thin the bone to ∼ 15 - μ m thickness. The window is then reinforced with cyanoacrylate glue and a coverslip to promote stability and optical access for at least a week. The head cap also includes a light-weight aluminum flange for head-fixation during imaging. Results: The resulting chronic thinned-skull window enables in vivo imaging to a typical cortical depth of ∼ 200 μ m without disruption of the intracranial environment. We highlight techniques to measure vascular structure and blood flow during development, including use of intravenous tracers and transgenic mice to label the blood plasma and vascular cell types, respectively. Conclusions: This protocol enables direct visualization of the developing neurogliovascular unit in the live neonatal brain during both normal and pathological states.
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Affiliation(s)
- Vanessa Coelho-Santos
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
- University of Washington, Department of Pediatrics, Seattle, Washington, United States
| | - Taryn Tieu
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
| | - Andy Y. Shih
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
- University of Washington, Department of Pediatrics, Seattle, Washington, United States
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
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17
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Faulhaber LD, D’Costa O, Shih AY, Gust J. Antibody-based in vivo leukocyte label for two-photon brain imaging in mice. Neurophotonics 2022; 9:031917. [PMID: 35637871 PMCID: PMC9128835 DOI: 10.1117/1.nph.9.3.031917] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Significance: To study leukocyte-endothelial interactions in a living system, robust and specific leukocyte labeling techniques are needed for in vivo two-photon microscopy of the cerebral microvasculature. Aim: We tested fluorophore-conjugated anti-CD45.2 monoclonal antibodies (mAb) to optimize dosing and two-photon imaging parameters for leukocyte labeling in healthy mice and a venous microstroke model. Approach: We retro-orbitally injected anti-CD45.2 mAb at 0.04, 0.4, and 2 mg / kg into BALB/c mice and used flow cytometry to analyze antibody saturation. Leukocyte labeling in the cortical microvasculature was examined by two-photon imaging. We also tested the application of CD45.2 mAb in a pathological leukocyte-endothelial adhesion model by photothrombotically occluding cortical penetrating venules. Results: We found that 0.4 mg / kg of anti-CD45.2 antibody intravenously was sufficient to label 95% of circulating leukocytes. There was no depletion of circulating leukocytes after 24 h at the dosages tested. Labeled leukocytes could be observed as deep as 550 μ m from the cortical surface. The antibody reliably labeled rolling, crawling, and adherent leukocytes in venules around the stroke-affected tissues. Conclusion: We show that the anti-CD45.2 mAb is a robust reagent for acute labeling of leukocytes during in vivo two-photon microscopy of the cortical microvasculature.
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Affiliation(s)
- Lila D. Faulhaber
- Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
- Seattle Children’s Research Institute, Center for Integrative Brain Research, Seattle, Washington, United States
| | - Olivia D’Costa
- Seattle Children’s Research Institute, Center for Integrative Brain Research, Seattle, Washington, United States
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
- University of Washington, Department of Pediatrics, Seattle, Washington, United States
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Juliane Gust
- Seattle Children’s Research Institute, Center for Integrative Brain Research, Seattle, Washington, United States
- University of Washington, Department of Neurology, Seattle, Washington, United States
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18
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Shih AY, Coelho-Santos V, Kılıç K. Special Section Guest Editorial: Imaging Neuroimmune, Neuroglial, and Neurovascular Interfaces. Neurophotonics 2022; 9:031901. [PMID: 36204654 PMCID: PMC9529636 DOI: 10.1117/1.nph.9.3.031901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The guest editorial provides an introduction to Parts 1 and 2 of the Neurophotonics Special Section on Imaging Neuroimmune, Neuroglial, and Neurovascular Interfaces.
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Affiliation(s)
- Andy Y. Shih
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
- University of Washington, Department of Pediatrics, Seattle, Washington, United States
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Vanessa Coelho-Santos
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, Seattle, Washington, United States
| | - Kıvılcım Kılıç
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
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19
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Bonney SK, Sullivan LT, Cherry TJ, Daneman R, Shih AY. Distinct features of brain perivascular fibroblasts and mural cells revealed by in vivo two-photon imaging. J Cereb Blood Flow Metab 2022; 42:966-978. [PMID: 34929105 PMCID: PMC9125487 DOI: 10.1177/0271678x211068528] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 11/11/2021] [Accepted: 11/19/2021] [Indexed: 12/04/2022]
Abstract
Perivascular fibroblasts (PVFs) are recognized for their pro-fibrotic role in many central nervous system disorders. Like mural cells, PVFs surround blood vessels and express Pdgfrβ. However, these shared attributes hinder the ability to distinguish PVFs from mural cells. We used in vivo two-photon imaging and transgenic mice with PVF-targeting promoters (Col1a1 or Col1a2) to compare the structure and distribution of PVFs and mural cells in cerebral cortex of healthy, adult mice. We show that PVFs localize to all cortical penetrating arterioles and their offshoots (arteriole-capillary transition zone), as well as the main trunk of only larger ascending venules. However, the capillary zone is devoid of PVF coverage. PVFs display short-range mobility along the vessel wall and exhibit distinct structural features (flattened somata and thin ruffled processes) not seen with smooth muscle cells or pericytes. These findings clarify that PVFs and mural cells are distinct cell types coexisting in a similar perivascular niche.
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Affiliation(s)
- Stephanie K Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Liam T Sullivan
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Timothy J Cherry
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Richard Daneman
- Departments of Neurosciences and Pharmacology, University of California San Diego, La Jolla, CA, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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20
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Abstract
Pericytes have myriad functions in cerebrovascular regulation but remain understudied in the living brain. To dissect pericyte functions in vivo, prior studies have used genetic approaches to induce global pericyte loss in the rodent brain. However, this leads to complex outcomes, making it challenging to disentangle the physiological roles of pericytes from the pathophysiological effects of their depletion. Here, we describe a protocol to optically ablate individual pericytes of the mouse cerebral cortex in vivo for fine-scale studies of pericyte function. The strategy relies on two-photon microscopy and cranial window-implanted transgenic mice with mural cell-specific expression of fluorescent proteins. Single pericyte somata are precisely targeted with pulsed infrared laser light to induce selective pericyte death, but without overt blood-brain barrier leakage. Following pericyte ablation, the changes to the local capillary network and remaining pericytes can be examined longitudinally. The approach has been used to study pericyte roles in capillary flow regulation, and the structural remodeling of pericytes involved in restoration of endothelial coverage after pericyte loss.
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Affiliation(s)
- Cara D. Nielson
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States,Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Stephanie K. Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States,Department of Pediatrics, University of Washington, Seattle, WA, United States,Department of Bioengineering, University of Washington, Seattle, WA, United States,*Correspondence: Andy Y. Shih,
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21
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Bonney SK, Coelho-Santos V, Huang SF, Takeno M, Kornfeld J, Keller A, Shih AY. Public Volume Electron Microscopy Data: An Essential Resource to Study the Brain Microvasculature. Front Cell Dev Biol 2022; 10:849469. [PMID: 35450291 PMCID: PMC9016339 DOI: 10.3389/fcell.2022.849469] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/21/2022] [Indexed: 01/09/2023] Open
Abstract
Electron microscopy is the primary approach to study ultrastructural features of the cerebrovasculature. However, 2D snapshots of a vascular bed capture only a small fraction of its complexity. Recent efforts to synaptically map neuronal circuitry using volume electron microscopy have also sampled the brain microvasculature in 3D. Here, we perform a meta-analysis of 7 data sets spanning different species and brain regions, including two data sets from the MICrONS consortium that have made efforts to segment vasculature in addition to all parenchymal cell types in mouse visual cortex. Exploration of these data have revealed rich information for detailed investigation of the cerebrovasculature. Neurovascular unit cell types (including, but not limited to, endothelial cells, mural cells, perivascular fibroblasts, microglia, and astrocytes) could be discerned across broad microvascular zones. Image contrast was sufficient to identify subcellular details, including endothelial junctions, caveolae, peg-and-socket interactions, mitochondria, Golgi cisternae, microvilli and other cellular protrusions of potential significance to vascular signaling. Additionally, non-cellular structures including the basement membrane and perivascular spaces were visible and could be traced between arterio-venous zones along the vascular wall. These explorations revealed structural features that may be important for vascular functions, such as blood-brain barrier integrity, blood flow control, brain clearance, and bioenergetics. They also identified limitations where accuracy and consistency of segmentation could be further honed by future efforts. The purpose of this article is to introduce these valuable community resources within the framework of cerebrovascular research. We do so by providing an assessment of their vascular contents, identifying features of significance for further study, and discussing next step ideas for refining vascular segmentation and analysis.
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Affiliation(s)
- Stephanie K. Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Sheng-Fu Huang
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zürich, University of Zürich, Zürich, Switzerland
- Neuroscience Center Zürich, University of Zürich and ETH Zürich, Zürich, Switzerland
| | - Marc Takeno
- Allen Institute for Brain Science, Seattle, WA, United States
| | | | - Annika Keller
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zürich, University of Zürich, Zürich, Switzerland
- Neuroscience Center Zürich, University of Zürich and ETH Zürich, Zürich, Switzerland
- *Correspondence: Annika Keller, ; Andy Y. Shih,
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington, Seattle, WA, United States
- Department of Bioengineering, University of Washington, Seattle, WA, United States
- *Correspondence: Annika Keller, ; Andy Y. Shih,
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22
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Abstract
The vast majority of the brain's vascular length is composed of capillaries, where our understanding of blood flow control remains incomplete. This review synthesizes current knowledge on the control of blood flow across microvascular zones by addressing issues with nomenclature and drawing on new developments from in vivo optical imaging and single-cell transcriptomics. Recent studies have highlighted important distinctions in mural cell morphology, gene expression, and contractile dynamics, which can explain observed differences in response to vasoactive mediators between arteriole, transitional, and capillary zones. Smooth muscle cells of arterioles and ensheathing pericytes of the arteriole-capillary transitional zone control large-scale, rapid changes in blood flow. In contrast, capillary pericytes downstream of the transitional zone act on slower and smaller scales and are involved in establishing resting capillary tone and flow heterogeneity. Many unresolved issues remain, including the vasoactive mediators that activate the different pericyte types in vivo, the role of pericyte-endothelial communication in conducting signals from capillaries to arterioles, and how neurological disease affects these mechanisms.
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Affiliation(s)
- David A Hartmann
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA; .,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA; .,Department of Pediatrics, University of Washington, Seattle, Washington, USA.,Department of Bioengineering, University of Washington, Seattle, Washington, USA
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23
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Abstract
The vast majority of the brain's vascular length is composed of capillaries, where our understanding of blood flow control remains incomplete. This review synthesizes current knowledge on the control of blood flow across microvascular zones by addressing issues with nomenclature and drawing on new developments from in vivo optical imaging and single-cell transcriptomics. Recent studies have highlighted important distinctions in mural cell morphology, gene expression, and contractile dynamics, which can explain observed differences in response to vasoactive mediators between arteriole, transitional, and capillary zones. Smooth muscle cells of arterioles and ensheathing pericytes of the arteriole-capillary transitional zone control large-scale, rapid changes in blood flow. In contrast, capillary pericytes downstream of the transitional zone act on slower and smaller scales and are involved in establishing resting capillary tone and flow heterogeneity. Many unresolved issues remain, including the vasoactive mediators that activate the different pericyte types in vivo, the role of pericyte-endothelial communication in conducting signals from capillaries to arterioles, and how neurological disease affects these mechanisms.
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Affiliation(s)
- David A Hartmann
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA;
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA;
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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24
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Whitehead SN, Bruno A, Burns JM, Carmichael ST, Csiszar A, Edwards JD, Elahi FM, Faraco G, Gould DB, Gustafson DR, Hachinski V, Rosenberg G, Sorond FA, Shih AY, Tse KH, Ungvari Z, Wilcock DM, Zuloaga KL, Barone FC. Expanding the horizon of research into the pathogenesis of the white matter diseases: Proceedings of the 2021 Annual Workshop of the Albert Research Institute for White Matter and Cognition. GeroScience 2022; 44:25-37. [PMID: 34606040 PMCID: PMC8488071 DOI: 10.1007/s11357-021-00461-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022] Open
Abstract
White matter pathologies are critically involved in the etiology of vascular cognitive impairment-dementia (VCID), Alzheimer's disease (AD), and Alzheimer's disease and related diseases (ADRD), and therefore need to be considered a treatable target ( Roseborough A, Hachinski V, Whitehead S. White matter degeneration - a treatable target? Roseborough et al. JAMA Neurol [Internet]. 2020 Apr 27;77(7):793-4, [1] . To help address this often-missed area of research, several workshops have been sponsored by the Leo and Anne Albert Charitable Trust since 2015, resulting in the incorporation of "The Albert Research Institute for White Matter and Cognition" in 2020. The first annual "Institute" meeting was held virtually on March 3-4, 2021. The Institute provides a forum and workspace for communication and support of the advancement of white matter science and research to better understand the evolution and prevention of dementia. It serves as a platform for young investigator development, to introduce new data and debate biology mechanisms and new ideas, and to encourage and support new research collaborations and directions to clarify how white matter changes, with other genetic and health risk factors, contribute to cognitive impairment. Similar to previous Albert Trust-sponsored workshops (Barone et al. in J Transl Med 14:1-14, [2]; Sorond et al. in GeroScience 42:81-96, [3]), established expert investigators were identified and invited to present. Opportunities to attend and present were also extended by invitation to talented research fellows and younger scientists. Also, updates on institute-funded research collaborations were provided and discussed. The summary that follows is a synopsis of topics and discussion covered in the workshop.
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Affiliation(s)
- Shawn N Whitehead
- Department of Anatomy and Cell Biology, Western University, London, ON, N6A 3K7, Canada.
| | - Askiel Bruno
- Department of Neurology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Jeffrey M Burns
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
| | - S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Jodi D Edwards
- University of Ottawa Heart Institute, Ottawa, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, K1G 5Z3, Canada
| | - Fanny M Elahi
- Memory and Aging Center, UCSF Weill Institute for Neurosciences, 675 Nelson Rising Lane, Suite 190, San Francisco, CA, 94158, USA
| | - Giuseppe Faraco
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Douglas B Gould
- Departments of Ophthalmology and Anatomy, and Institute for Human Genetics, School of Medicine, University of California, San Francisco, 94143, USA
| | - Deborah R Gustafson
- Department of Neurology, Section for NeuroEpidemiology, State University of New York Downstate Health Sciences University, New York, Brooklyn, 11203, USA
| | - Vladimir Hachinski
- Department of Clinical Neurological Sciences, Western University, London, ON, N6A 5C1, Canada
| | - Gary Rosenberg
- UNM Health Sciences Center, University of New Mexico, Albuquerque, NM, 87106, USA
| | | | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute; Department of Pediatrics; Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Kai Hei Tse
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Donna M Wilcock
- Sanders-Brown Center on Aging; Department of Neurology, Department of Behavioral Science, University of Kentucky, Lexington, KY, 40536, USA
| | - Kristen L Zuloaga
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Frank C Barone
- Department of Neurology, SUNY Downstate Health Sciences University, Brooklyn, NY, 11203, USA
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25
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Coelho Santos V, Tieu T, Kilby M, Shih AY. Abstract TP249: Early-lifechronic Intermittent Hypoxia Susceptibility For Anxiety-like Behaviors: Focus On Cerebrovascular Alterations. Stroke 2022. [DOI: 10.1161/str.53.suppl_1.tp249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Premature birth is a major public health issue affecting 1 in 10 deliveries worldwide. One of the most common diagnoses in these infants is apnea of prematurity, with chronic intermittent hypoxia (CIH) as one hallmark, which includes interlacing hypoxia and normoxia episodes. The perinatal brain is vulnerable to hypoxia because it is a shifting landscape with marked growth and remodeling of the vasculature. Hypoxia provides a natural angiogenic stimulus during growth of cerebrovascular networks. However, it is unclear if exposure to CIH alters the structure and function of developing brain vascular networks. To further investigate this question, we used a neonatal mouse model that mimics the hypoxia/reoxygenation events occurring in CIH. From postnatal day P2 to P12, pups were exposed to 20.9% O
2
(normoxia) and 5.7% O
2
(hypoxia; 25-30 episodes of 5-7s per hour) for 8 hours a day during daylight hours. Our previous studies examining mouse pups (P8-P12) reared in normoxic conditions showed that ascending venules were a key locus for new vascular growth during brain capillary development. Concurrently, an initially amorphous plexus of pial venules on the cortical surface undergoes massive intussusceptive remodeling to create an optimized tree-like network for cortical blood drainage. During CIH,
in vivo
two-photon imaging revealed that angiogenic sprouts emerged not only from venules but also from cortical arterioles. CIH led to more active angiogenesis and increased brain capillary length and branching. In addition, arteriovenous shunts were present within the pial vasculature. Critically, we observed that mice exposure to CIH during the neonatal period presented anxiety and mood like-behaviors (interupted grooming and jump/scape behavior) at weaning age (P21). Curiously, mice exposed to CIH exhibited improved recognition memory (novel object recognition) at P30. These findings begin to clarify the vascular changes induced by CIH and their association with behavioral abnormalities after development with CIH.
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Affiliation(s)
| | - Taryn Tieu
- Seattle Children's Rsch Institu, Seattle, WA
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26
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Faulhaber LD, Phuong AQ, Hartsuyker KJ, Cho Y, Mand KK, Harper SD, Olson AK, Garden GA, Shih AY, Gust J. Brain capillary obstruction during neurotoxicity in a mouse model of anti-CD19 chimeric antigen receptor T-cell therapy. Brain Commun 2021; 4:fcab309. [PMID: 35169706 PMCID: PMC8833245 DOI: 10.1093/braincomms/fcab309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/19/2021] [Accepted: 12/30/2021] [Indexed: 01/13/2023] Open
Abstract
Immunotherapy for haematologic malignancies with CD19-directed chimeric antigen receptor T cells has been highly successful at eradicating cancer but is associated with acute neurotoxicity in ∼40% of patients. This neurotoxicity correlates with systemic cytokine release syndrome, endothelial activation and disruption of endothelial integrity, but it remains unclear how these mechanisms interact and how they lead to neurologic dysfunction. We hypothesized that dysfunction of the neurovascular unit is a key step in the development of neurotoxicity. To recapitulate the interaction of the intact immune system with the blood-brain barrier, we first developed an immunocompetent mouse model of chimeric antigen receptor T-cell treatment-associated neurotoxicity. We treated wild-type mice with cyclophosphamide lymphodepletion followed by escalating doses of murine CD19-directed chimeric antigen receptor T cells. Within 3-5 days after chimeric antigen receptor T-cell infusion, these mice developed systemic cytokine release and abnormal behaviour as measured by daily neurologic screening exams and open-field testing. Histologic examination revealed widespread brain haemorrhages, diffuse extravascular immunoglobulin deposition, loss of capillary pericyte coverage and increased prevalence of string capillaries. To measure any associated changes in cerebral microvascular blood flow, we performed in vivo two-photon imaging through thinned-skull cranial windows. Unexpectedly, we found that 11.9% of cortical capillaries were plugged by Day 6 after chimeric antigen receptor T-cell treatment, compared to 1.1% in controls treated with mock transduced T cells. The capillary plugs comprised CD45+ leucocytes, a subset of which were CD3+ T cells. Plugging of this severity is expected to compromise cerebral perfusion. Indeed, we found widely distributed patchy hypoxia by hypoxyprobe immunolabelling. Increased serum levels of soluble ICAM-1 and VCAM-1 support a putative mechanism of increased leucocyte-endothelial adhesion. These data reveal that brain capillary obstruction may cause sufficient microvascular compromise to explain the clinical phenotype of chimeric antigen receptor T-cell neurotoxicity. The translational impact of this finding is strengthened by the fact that our mouse model closely approximates the kinetics and histologic findings of the chimeric antigen receptor T-cell neurotoxicity syndrome seen in human patients. This new link between systemic immune activation and neurovascular unit injury may be amenable to therapeutic intervention.
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Affiliation(s)
- Lila D. Faulhaber
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Anthea Q. Phuong
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Kendra Jae Hartsuyker
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Yeheun Cho
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Katie K. Mand
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Stuart D. Harper
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Aaron K. Olson
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Gwenn A. Garden
- Department of Neurology, University of Washington, Seattle, WA 98195, USA
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Juliane Gust
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Neurology, University of Washington, Seattle, WA 98195, USA
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27
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Liao FF, Lin G, Chen X, Chen L, Zheng W, Raghow R, Zhou FM, Shih AY, Tan XL. Endothelial Nitric Oxide Synthase-Deficient Mice: A Model of Spontaneous Cerebral Small-Vessel Disease. Am J Pathol 2021; 191:1932-1945. [PMID: 33711310 PMCID: PMC8647425 DOI: 10.1016/j.ajpath.2021.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 02/04/2021] [Accepted: 02/24/2021] [Indexed: 02/08/2023]
Abstract
Age-related cerebral small-vessel disease (CSVD) is a major cause of stroke and dementia. Despite a widespread acceptance of small-vessel arteriopathy, lacunar infarction, diffuse white matter injury, and cognitive impairment as four cardinal features of CSVD, a unifying pathologic mechanism of CSVD remains elusive. Herein, we introduce partial endothelial nitric oxide synthase (eNOS)-deficient mice as a model of age-dependent, spontaneous CSVD. These mice developed cerebral hypoperfusion and blood-brain barrier leakage at a young age, which progressively worsened with advanced age. Their brains exhibited elevated oxidative stress, astrogliosis, cerebral amyloid angiopathy, microbleeds, microinfarction, and white matter pathology. Partial eNOS-deficient mice developed gait disturbances at middle age, and hippocampus-dependent memory deficits at older ages. These mice also showed enhanced expression of bone morphogenetic protein 4 (BMP4) in brain pericytes before myelin loss and white matter pathology. Because BMP4 signaling not only promotes astrogliogenesis but also blocks oligodendrocyte differentiation, we posit that paracrine actions of BMP4, localized within the neurovascular unit, promote white matter disorganization and neurodegeneration. These observations point to BMP4 signaling pathway in the aging brain vasculature as a potential therapeutic target. Finally, because studies in partial eNOS-deficient mice corroborated recent clinical evidence that blood-brain barrier disruption is a primary cause of white matter pathology, the mechanism of impaired nitric oxide signaling-mediated CSVD warrants further investigation.
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Affiliation(s)
- Francesca-Fang Liao
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee.
| | - Geng Lin
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee; Department of Histology and Embryology, Basic Medical University, China Medical University, Shenyang, China
| | - Xingyong Chen
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee; Department of Neurology, Fujian Provincial Hospital, Provincial Clinical College of Fujian Medical University, Fuzhou, China
| | - Ling Chen
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee; Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Wei Zheng
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee; Department of Histology and Embryology, Basic Medical University, China Medical University, Shenyang, China
| | - Rajendra Raghow
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee
| | - Fu-Ming Zhou
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington
| | - Xing-Lin Tan
- Department of Pharmacology, Addiction Science, Toxicology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee; Department of Neurology, Nanhai Hospital of Southern Medical University, Foshan, China
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28
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O'Herron P, Hartmann D, Shih AY. Abstract P434: A Mouse Model To Control Vessel Diameter With Light. Circ Res 2021. [DOI: 10.1161/res.129.suppl_1.p434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In diseases such as stroke, hypertension, vascular cognitive impairment, and Alzheimer’s disease, defects in the cerebrovascular system lead to reduced blood flow and vasoreactivity to stimuli. Recently, there has been increased appreciation for the role of small vessels in these vascular pathologies. For example, small vessel dysfunction can cause widespread microinfarcts and capillary stalling, which may underlie cognitive impairment in cases where large scale vascular abnormalities are not readily detected. However, vascular function is difficult to dissociate from concurrent neuronal deficits cause by damage to neuronal circuitry in brain pathology. Thus the ability to directly probe smooth muscle contraction of small, individual vessels in the intact brain would be a valuable tool for increasing our understanding of vascular contributions to cognitive impairment. We developed an experimental paradigm to optically probe the contractile function of arterioles in vivo with high spatiotemporal precision. This was done by expressing the excitatory opsin ReaChR in vascular smooth muscle cells and pericytes. Using a 594 nm light-emitting diode we were able to evoke widespread vasoconstriction across the cranial window. With a 1040 nm focused, pulsed laser for two-photon stimulation, we were able to evoke highly localized constrictions targeted to individual pial artery branches or penetrating arterioles. Our dual light-path imaging system allowed the optogenetic stimulation to be performed with simultaneous two-photon imaging to monitor vessel activity. Using a spatial light modulator, we were also able to constrict vessels both above and below the imaging plane. This is a powerful tool to assay vasoconstrictive function of single arterioles across 3-dimensional vascular networks in vivo. It also presents novel opportunities to study conductance of vascular signals and to modulate dynamics of functional hyperemia.
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29
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Ornelas S, Berthiaume AA, Bonney SK, Coelho-Santos V, Underly RG, Kremer A, Guérin CJ, Lippens S, Shih AY. Three-dimensional ultrastructure of the brain pericyte-endothelial interface. J Cereb Blood Flow Metab 2021; 41:2185-2200. [PMID: 33970018 PMCID: PMC8393306 DOI: 10.1177/0271678x211012836] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pericytes and endothelial cells share membranous interdigitations called "peg-and-socket" interactions that facilitate their adhesion and biochemical crosstalk during vascular homeostasis. However, the morphology and distribution of these ultrastructures have remained elusive. Using a combination of 3D electron microscopy techniques, we examined peg-and-socket interactions in mouse brain capillaries. We found that pegs extending from pericytes to endothelial cells were morphologically diverse, exhibiting claw-like morphologies at the edge of the cell and bouton-shaped swellings away from the edge. Reciprocal endothelial pegs projecting into pericytes were less abundant and appeared as larger columnar protuberances. A large-scale 3D EM data set revealed enrichment of both pericyte and endothelial pegs around pericyte somata. The ratio of pericyte versus endothelial pegs was conserved among the pericytes examined, but total peg abundance was heterogeneous across cells. These data show considerable investment between pericytes and endothelial cells, and provide morphological evidence for pericyte somata as sites of enriched physical and biochemical interaction.
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Affiliation(s)
- Sharon Ornelas
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Stephanie K Bonney
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Robert G Underly
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Anna Kremer
- VIB BioImaging Core, VIB, Ghent, Belgium
- VIB Inflammation Research Center, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Christopher J Guérin
- VIB BioImaging Core, VIB, Ghent, Belgium
- VIB Inflammation Research Center, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Saskia Lippens
- VIB BioImaging Core, VIB, Ghent, Belgium
- VIB Inflammation Research Center, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Andy Y Shih, Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, 1900 9th Avenue M/S JMB.-5, Seattle, WA 98101, USA.
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30
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Rayner SG, Howard CC, Mandrycky CJ, Stamenkovic S, Himmelfarb J, Shih AY, Zheng Y. Microvasculatures: Multiphoton‐Guided Creation of Complex Organ‐Specific Microvasculature (Adv. Healthcare Mater. 10/2021). Adv Healthc Mater 2021. [DOI: 10.1002/adhm.202170048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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31
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Rayner SG, Howard CC, Mandrycky CJ, Stamenkovic S, Himmelfarb J, Shih AY, Zheng Y. Multiphoton-Guided Creation of Complex Organ-Specific Microvasculature. Adv Healthc Mater 2021; 10:e2100031. [PMID: 33586357 PMCID: PMC8137585 DOI: 10.1002/adhm.202100031] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/01/2021] [Indexed: 12/14/2022]
Abstract
Engineering functional human tissues in vitro is currently limited by difficulty replicating the small caliber, complex connectivity, cellularity, and 3D curvature of the native microvasculature. Multiphoton ablation has emerged as a promising technique for fabrication of microvascular structures with high resolution and full 3D control, but cellularization and perfusion of complex capillary-scale structures has remained challenging. Here, multiphoton ablation combined with guided endothelial cell growth from pre-formed microvessels is used to successfully create perfusable and cellularized organ-specific microvascular structures at anatomic scale within collagen hydrogels. Fabrication and perfusion of model 3D pulmonary and renal microvascular beds is demonstrated, as is replication and perfusion of a brain microvascular unit derived from in vivo data. Successful endothelialization and blood perfusion of a kidney-specific microvascular structure is achieved, using laser-guided angiogenesis. Finally, proof-of-concept hierarchical blood vessels and complex multicellular models are created, using multistep patterning with multiphoton ablation techniques. These successes open new doors for the creation of engineered tissues and organ-on-a-chip devices.
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Affiliation(s)
- Samuel G. Rayner
- Department of Bioengineering, University of Washington, 850 Republican St., Seattle, WA 98109, USA
- Department of Medicine; Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Seattle, WA 98195, USA
| | - Caitlin C. Howard
- Department of Bioengineering, University of Washington, 850 Republican St., Seattle, WA 98109, USA
| | - Christian J. Mandrycky
- Department of Bioengineering, University of Washington, 850 Republican St., Seattle, WA 98109, USA
| | | | - Jonathan Himmelfarb
- Department of Bioengineering, University of Washington, 850 Republican St., Seattle, WA 98109, USA
- Department of Medicine; Division of Nephrology, University of Washington, Seattle, WA 98195, USA
- Kidney Research Institute, Seattle, WA 98104, USA
| | - Andy Y. Shih
- Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Ying Zheng
- Department of Bioengineering, University of Washington, 850 Republican St., Seattle, WA 98109, USA
- Kidney Research Institute, Seattle, WA 98104, USA
- Institute for Stem Cell and Regenerative Medicine, Seattle, WA 98195, USA
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32
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McDowell KP, Berthiaume AA, Tieu T, Hartmann DA, Shih AY. VasoMetrics: unbiased spatiotemporal analysis of microvascular diameter in multi-photon imaging applications. Quant Imaging Med Surg 2021; 11:969-982. [PMID: 33654670 PMCID: PMC7829163 DOI: 10.21037/qims-20-920] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/17/2020] [Indexed: 01/13/2023]
Abstract
BACKGROUND Multi-photon imaging of the cerebrovasculature provides rich data on the dynamics of cortical arterioles, capillaries, and venules. Vascular diameter is the major determinant of blood flow resistance, and is the most commonly quantified metric in studies of the cerebrovasculature. However, there is a lack of accessible and easy-to-use methods to quantify vascular diameter in imaging data. METHODS We created VasoMetrics, a macro written in ImageJ/Fiji for spatiotemporal analysis of microvascular diameter. The key feature of VasoMetrics is rapid analysis of many evenly spaced cross-sectional lines along the vessel of interest, permitting the extraction of numerous diameter measurements from individual vessels. Here we demonstrated the utility of VasoMetrics by analyzing in vivo multi-photon imaging stacks and movies collected from lightly sedated mice, as well as data from optical coherence tomography angiography (OCTA) of human retina. RESULTS Compared to the standard approach, which is to measure cross-sectional diameters at arbitrary points along a vessel, VasoMetrics accurately reported spatiotemporal features of vessel diameter, reduced measurement bias and time spent analyzing data, and improved the reproducibility of diameter measurements between users. VasoMetrics revealed the dynamics in pial arteriole diameters during vasomotion at rest, as well as changes in capillary diameter before and after pericyte ablation. Retinal arteriole diameter was quantified from a human retinal angiogram, providing proof-of-principle that VasoMetrics can be applied to contrast-enhanced clinical imaging of microvasculature. CONCLUSIONS VasoMetrics is a robust macro for spatiotemporal analysis of microvascular diameter in imaging applications.
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Affiliation(s)
- Konnor P. McDowell
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Taryn Tieu
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - David A. Hartmann
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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33
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Underly RG, Shih AY. Rapid, Nitric Oxide Synthesis-Dependent Activation of MMP-9 at Pericyte Somata During Capillary Ischemia in vivo. Front Physiol 2021; 11:619230. [PMID: 33505320 PMCID: PMC7830159 DOI: 10.3389/fphys.2020.619230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/10/2020] [Indexed: 11/28/2022] Open
Abstract
Nitric oxide serves essential roles in normal vascular physiology, but paradoxically contributes to vascular pathology in disease. During brain ischemia, aberrant nitric oxide levels can cause cellular injury through induction of nitrosative/oxidative stress and post-translational activation of matrix-metalloproteinase-9 (MMP-9). We recently demonstrated that brain pericyte somata were associated with very early and localized MMP-9 activation along capillaries during cerebral ischemia, leading to focal blood-brain barrier disruption. Here, we tested whether this effect was dependent upon nitric oxide production. In vivo two-photon imaging was used to directly visualize MMP9 activity using a FITC-gelatin probe and leakage of intravenous dye during photothrombotically induced capillary ischemia. Results showed that the NOS inhibitor, L-NIL, at concentrations affecting both iNOS and constitutive NOS isoforms, attenuated capillary leakage at pericyte soma-specific locations and substantially reduced FITC-gelatin cleavage. We also found that combined administration of L-NIL and anisomycin, an inhibitor of protein synthesis, led to near complete elimination of FITC-gelatin cleavage and vascular leakage. These results indicate that both nitric oxide synthase and new protein synthesis are involved in the rapid activation of MMP-9 at somata of capillary pericytes during ischemia.
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Affiliation(s)
- Robert G Underly
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States.,Department of Bioengineering, University of Washington, Seattle, WA, United States
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34
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Watson AN, Berthiaume AA, Faino AV, McDowell KP, Bhat NR, Hartmann DA, Shih AY. Mild pericyte deficiency is associated with aberrant brain microvascular flow in aged PDGFRβ +/- mice. J Cereb Blood Flow Metab 2020; 40:2387-2400. [PMID: 31987006 PMCID: PMC7820684 DOI: 10.1177/0271678x19900543] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The receptor tyrosine kinase PDGFRβ is essential for pericyte migration to the endothelium. In mice lacking one allele of PDGFRβ (PDGFRβ+/-), previous reports have described an age-dependent loss of pericytes in the brain, leading to cerebrovascular dysfunction and subsequent neurodegeneration reminiscent of that seen in Alzheimer's disease and vascular dementia. We examined 12-20-month-old PDGFRβ+/- mice to better understand how pericyte loss affects brain microvascular structure and perfusion in vivo. We observed a mild reduction of cortical pericyte number in PDGFRβ+/- mice (27% fewer cell bodies) compared to controls, but no decrease in pericyte coverage of the endothelium. This mild degree of pericyte loss caused no discernable change in cortical microvascular density, length, basal diameter or reactivity to hypercapnia. Yet, it was associated with an increase in basal blood cell velocity, primarily in pre-capillary arterioles. Taken together, our results suggest that mild pericyte loss can lead to aberrant cerebral blood flow despite a lack of apparent effect on microvascular structure and reactivity.
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Affiliation(s)
- Ashley N Watson
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Andree-Anne Berthiaume
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Anna V Faino
- Children's Core for Biomedical Statistics, Seattle Children's Research Institute, Seattle, WA, USA
| | - Konnor P McDowell
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Narayan R Bhat
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - David A Hartmann
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA.,Children's Core for Biomedical Statistics, Seattle Children's Research Institute, Seattle, WA, USA.,Department of Pediatrics, University of Washington, Seattle, WA, USA
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O'Herron P, Summers PM, Shih AY, Kara P, Woodward JJ. In vivo two-photon imaging of neuronal and brain vascular responses in mice chronically exposed to ethanol. Alcohol 2020; 85:41-47. [PMID: 31857103 DOI: 10.1016/j.alcohol.2019.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 12/11/2022]
Abstract
The effects of ethanol on brain function have been extensively studied using a variety of in vitro and in vivo techniques. For example, electrophysiological studies using brain slices from rodents and non-human primates have demonstrated that acute and chronic exposure to ethanol alters the intrinsic excitability and synaptic signaling of neurons within cortical and sub-cortical areas of the brain. In humans, neuroimaging studies reveal alterations in measures of brain activation and connectivity in subjects with alcohol use disorder. While complementary, these methods are inherently limited due to issues related to either disruption of normal sensory input (in vitro slice studies) or resolution (whole brain imaging). In the present study, we used 2-photon laser scanning microscopy in intact animals to assess the impact of chronic ethanol exposure on sensory-evoked neuronal and vascular responses. Adult male C57BL/6J mice were exposed to four weekly cycles of chronic intermittent ethanol (CIE) exposure, while control mice were exposed to air. After withdrawal (≥72 h), a cranial window was placed over the primary visual cortex (V1), and sensory-evoked responses were monitored using the calcium indicator OGB-1. CIE exposure produced small but significant changes in response amplitude (decrease) and orientation selectivity of V1 neurons (increase). While arteriole diameter did not differ between control and CIE mice under baseline conditions, sensory-evoked dilation was enhanced in vessels from CIE-exposed mice as compared to controls. This was accompanied by a reduced latency in response to stimulation. In separate experiments, pial arteriole diameter was measured in the barrel cortex of control and CIE-exposed mice. Baseline diameter of barrel cortex arterioles was similar between control and CIE-exposed mice, but unlike vessels in V1, sensory-evoked dilation of barrel cortex arterioles was similar between the two groups. Together, the results of these studies suggest that chronic exposure to alcohol induces changes in neurovascular coupling that are region-dependent.
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Coelho‐Santos V, Shih AY. Postnatal development of cerebrovascular structure and the neurogliovascular unit. Wiley Interdiscip Rev Dev Biol 2020; 9:e363. [PMID: 31576670 PMCID: PMC7027551 DOI: 10.1002/wdev.363] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/22/2022]
Abstract
The unceasing metabolic demands of brain function are supported by an intricate three-dimensional network of arterioles, capillaries, and venules, designed to effectively distribute blood to all neurons and to provide shelter from harmful molecules in the blood. The development and maturation of this microvasculature involves a complex interplay between endothelial cells with nearly all other brain cell types (pericytes, astrocytes, microglia, and neurons), orchestrated throughout embryogenesis and the first few weeks after birth in mice. Both the expansion and regression of vascular networks occur during the postnatal period of cerebrovascular remodeling. Pial vascular networks on the brain surface are dense at birth and are then selectively pruned during the postnatal period, with the most dramatic changes occurring in the pial venular network. This is contrasted to an expansion of subsurface capillary networks through the induction of angiogenesis. Concurrent with changes in vascular structure, the integration and cross talk of neurovascular cells lead to establishment of blood-brain barrier integrity and neurovascular coupling to ensure precise control of macromolecular passage and metabolic supply. While we still possess a limited understanding of the rules that control cerebrovascular development, we can begin to assemble a view of how this complex process evolves, as well as identify gaps in knowledge for the next steps of research. This article is categorized under: Nervous System Development > Vertebrates: Regional Development Vertebrate Organogenesis > Musculoskeletal and Vascular Nervous System Development > Vertebrates: General Principles.
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Affiliation(s)
- Vanessa Coelho‐Santos
- Center for Developmental Biology and Regenerative MedicineSeattle Children's Research InstituteSeattleWashington
- Department of PediatricsUniversity of WashingtonSeattleWashington
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative MedicineSeattle Children's Research InstituteSeattleWashington
- Department of PediatricsUniversity of WashingtonSeattleWashington
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Sorond FA, Whitehead S, Arai K, Arnold D, Carmichael ST, De Carli C, Duering M, Fornage M, Flores-Obando RE, Graff-Radford J, Hamel E, Hess DC, Ihara M, Jensen MK, Markus HS, Montagne A, Rosenberg G, Shih AY, Smith EE, Thiel A, Tse KH, Wilcock D, Barone F. Proceedings from the Albert Charitable Trust Inaugural Workshop on white matter and cognition in aging. GeroScience 2019; 42:81-96. [PMID: 31811528 DOI: 10.1007/s11357-019-00141-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 12/13/2022] Open
Abstract
This third in a series of vascular cognitive impairment (VCI) workshops, supported by "The Leo and Anne Albert Charitable Trust," was held from February 8 to 12 at the Omni Resort in Carlsbad, CA. This workshop followed the information gathered from the earlier two workshops suggesting that we focus more specifically on brain white matter in age-related cognitive impairment. The Scientific Program Committee (Frank Barone, Shawn Whitehead, Eric Smith, and Rod Corriveau) assembled translational, clinical, and basic scientists with unique expertise in acute and chronic white matter injury at the intersection of cerebrovascular and neurodegenerative etiologies. As in previous Albert Trust workshops, invited participants addressed key topics related to mechanisms of white matter injury, biomarkers of white matter injury, and interventions to prevent white matter injury and age-related cognitive decline. This report provides a synopsis of the presentations and discussions by the participants, including the existing knowledge gaps and the delineation of the next steps towards advancing our understanding of white matter injury and age-related cognitive decline. Workshop discussions and consensus resulted in action by The Albert Trust to (1) increase support from biannual to annual "White Matter and Cognition" workshops; (2) provide funding for two collaborative, novel research grants annually submitted by meeting participants; and (3) coordinate the formation of the "Albert Research Institute for White Matter and Cognition." This institute will fill a gap in white matter science, providing white matter and cognition communications, including annual updates from workshops and the literature and interconnecting with other Albert Trust scientific endeavors in cognition and dementia, and providing support for newly established collaborations between seasoned investigators and to the development of talented young investigators in the VCI-dementia (VCID) and white matter cognition arena.
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Affiliation(s)
- Farzaneh A Sorond
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA.
| | - Shawn Whitehead
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Ken Arai
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Douglas Arnold
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - S Thomas Carmichael
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Charles De Carli
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Marco Duering
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Myriam Fornage
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Rafael E Flores-Obando
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Jonathan Graff-Radford
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Edith Hamel
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - David C Hess
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Massafumi Ihara
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Majken K Jensen
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Hugh S Markus
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Axel Montagne
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Gary Rosenberg
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Andy Y Shih
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Eric E Smith
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Alex Thiel
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Kai Hei Tse
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Donna Wilcock
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
| | - Frank Barone
- Department of Neurology, Division Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, 625 N. Michigan Ave, suite 1150, Chicago, IL, 60611, USA
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Berthiaume AA, Grant RI, McDowell KP, Underly RG, Hartmann DA, Levy M, Bhat NR, Shih AY. Dynamic Remodeling of Pericytes In Vivo Maintains Capillary Coverage in the Adult Mouse Brain. Cell Rep 2019; 22:8-16. [PMID: 29298435 DOI: 10.1016/j.celrep.2017.12.016] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/01/2017] [Accepted: 12/03/2017] [Indexed: 12/16/2022] Open
Abstract
Direct contact and communication between pericytes and endothelial cells is critical for maintenance of cerebrovascular stability and blood-brain barrier function. Capillary pericytes have thin processes that reach hundreds of micrometers along the capillary bed. The processes of adjacent pericytes come in close proximity but do not overlap, yielding a cellular chain with discrete territories occupied by individual pericytes. Little is known about whether this pericyte chain is structurally dynamic in the adult brain. Using in vivo two-photon imaging in adult mouse cortex, we show that while pericyte somata were immobile, the tips of their processes underwent extensions and/or retractions over days. The selective ablation of single pericytes provoked exuberant extension of processes from neighboring pericytes to contact uncovered regions of the endothelium. Uncovered capillary regions had normal barrier function but were dilated until pericyte contact was regained. Pericyte structural plasticity may be critical for cerebrovascular health and warrants detailed investigation.
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Affiliation(s)
- Andrée-Anne Berthiaume
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Roger I Grant
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Konnor P McDowell
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Robert G Underly
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - David A Hartmann
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Manuel Levy
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Narayan R Bhat
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC 29425, USA.
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Grant RI, Hartmann DA, Underly RG, Berthiaume AA, Bhat NR, Shih AY. Organizational hierarchy and structural diversity of microvascular pericytes in adult mouse cortex. J Cereb Blood Flow Metab 2019; 39:411-425. [PMID: 28933255 PMCID: PMC6399730 DOI: 10.1177/0271678x17732229] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Smooth muscle cells and pericytes, together called mural cells, coordinate many distinct vascular functions. Canonically, smooth muscle cells are ring-shaped and cover arterioles with circumferential processes, whereas pericytes extend thin processes that run longitudinally along capillaries. In between these canonical mural cell types are cells with features of both smooth muscle cells and pericytes. Recent studies suggest that these transitional cells are critical for controlling blood flow to the capillary bed during health and disease, but there remains confusion on how to identify them and where they are located in the brain microvasculature. To address this issue, we measured the morphology, vascular territory, and α-smooth muscle actin content of structurally diverse mural cells in adult mouse cortex. We first imaged intact 3D vascular networks to establish the locations of major gradations in mural cell appearance as arterioles branched into capillaries. We then imaged individual mural cells occupying the regions within these gradations. This revealed two transitional cells that were often similar in appearance, but with sharply contrasting levels of α-smooth muscle actin. Our findings highlight the diversity of mural cell morphologies in brain microvasculature, and provide guidance for identification and categorization of mural cell types.
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Affiliation(s)
- Roger I Grant
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - David A Hartmann
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Robert G Underly
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | | | - Narayan R Bhat
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,2 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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Hyacinth HI, Sugihara CL, Spencer TL, Archer DR, Shih AY. Higher prevalence of spontaneous cerebral vasculopathy and cerebral infarcts in a mouse model of sickle cell disease. J Cereb Blood Flow Metab 2019; 39:342-351. [PMID: 28925802 PMCID: PMC6365608 DOI: 10.1177/0271678x17732275] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Stroke is a dramatic complication of sickle cell disease (SCD), which is associated with cerebral vasculopathies including moya moya, intravascular thrombi, cerebral hyperemia, and increased vessel tortuosity. The spontaneous occurrence of these pathologies in the sickle cell mouse model has not been described. Here, we studied Townes humanized sickle cell and age-matched control mice that were 13 months old. We used in vivo two-photon microscopy to assess blood flow dynamics, vascular topology, and evidence of cerebral vasculopathy. Results showed that compared to controls, sickle cell mice had significantly higher red blood cell (RBC) velocity (0.73 mm/s vs. 0.55 mm/s, p = 0.013), capillary vessel diameter (4.84 µM vs. 4.50 µM, p = 0.014), and RBC volume flux (0.015 nL/s vs. 0.010 nL/s, p = 0.021). Also, sickle cell mice had significantly more tortuous capillary vessels ( p < 0.0001) and significantly shorter capillary vessel branches ( p = 0.0065) compared to controls. Sickle cell mice also had significantly higher number of capillary occlusive events (3.4% vs. 1.9%, p < 0.0001) and RBC stalls (3.8% vs. 2.1%, p < 0.0001) in the cerebral capillary bed. In post-mortem immunohistochemical analyses, sickle cell mice had a 2.5-fold higher frequency of cortical microinfarcts compared to control mice. Our results suggest that aged Townes sickle cell mice spontaneously develop SCD-associated cerebral vasculopathy.
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Affiliation(s)
- Hyacinth I Hyacinth
- 1 Department of Pediatrics, Aflac Cancer and Blood Disorder Center of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, USA
| | - Courtney L Sugihara
- 2 Neuroscience and Behavioral Biology Program, Emory University, Atlanta, GA, USA
| | - Thomas L Spencer
- 3 Department of Mechanical Engineering, Georgia Technical Institute, Atlanta, GA, USA
| | - David R Archer
- 1 Department of Pediatrics, Aflac Cancer and Blood Disorder Center of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, USA
| | - Andy Y Shih
- 4 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,5 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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Berthiaume AA, Hartmann DA, Majesky MW, Bhat NR, Shih AY. Pericyte Structural Remodeling in Cerebrovascular Health and Homeostasis. Front Aging Neurosci 2018; 10:210. [PMID: 30065645 PMCID: PMC6057109 DOI: 10.3389/fnagi.2018.00210] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/22/2018] [Indexed: 12/21/2022] Open
Abstract
The biology of brain microvascular pericytes is an active area of research and discovery, as their interaction with the endothelium is critical for multiple aspects of cerebrovascular function. There is growing evidence that pericyte loss or dysfunction is involved in the pathogenesis of Alzheimer’s disease, vascular dementia, ischemic stroke and brain injury. However, strategies to mitigate or compensate for this loss remain limited. In this review, we highlight a novel finding that pericytes in the adult brain are structurally dynamic in vivo, and actively compensate for loss of endothelial coverage by extending their far-reaching processes to maintain contact with regions of exposed endothelium. Structural remodeling of pericytes may present an opportunity to foster pericyte-endothelial communication in the adult brain and should be explored as a potential means to counteract pericyte loss in dementia and cerebrovascular disease. We discuss the pathophysiological consequences of pericyte loss on capillary function, and the biochemical pathways that may control pericyte remodeling. We also offer guidance for observing pericytes in vivo, such that pericyte structural remodeling can be more broadly studied in mouse models of cerebrovascular disease.
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Affiliation(s)
- Andrée-Anne Berthiaume
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - David A Hartmann
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Mark W Majesky
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States.,Departments of Pediatrics and Pathology, University of Washington, Seattle, WA, United States
| | - Narayan R Bhat
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States.,Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States
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Hartmann D, Grant RI, Harrill SA, Noonan T, Lauer A, Shih AY. Optogenetic stimulation of pericytes lacking alpha smooth muscle actin produces a decrease in capillary blood flow in the living mouse brain. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.708.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David Hartmann
- NeurosciencesMedical University of South CarolinaCharlestonSC
| | - Roger Ian Grant
- NeurosciencesMedical University of South CarolinaCharlestonSC
| | | | | | | | - Andy Y. Shih
- NeurosciencesMedical University of South CarolinaCharlestonSC
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Shih AY, Hyacinth HI, Hartmann DA, van Veluw SJ. Rodent Models of Cerebral Microinfarct and Microhemorrhage. Stroke 2018; 49:803-810. [PMID: 29459393 DOI: 10.1161/strokeaha.117.016995] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Andy Y Shih
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.).
| | - Hyacinth I Hyacinth
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.)
| | - David A Hartmann
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.)
| | - Susanne J van Veluw
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.)
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Hartmann DA, Hyacinth HI, Liao FF, Shih AY. Does pathology of small venules contribute to cerebral microinfarcts and dementia? J Neurochem 2017; 144:517-526. [PMID: 28950410 DOI: 10.1111/jnc.14228] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 09/08/2017] [Accepted: 09/18/2017] [Indexed: 12/28/2022]
Abstract
Microinfarcts are small, but strikingly common, ischemic brain lesions in the aging human brain. There is mounting evidence that microinfarcts contribute to vascular cognitive impairment and dementia, but the origins of microinfarcts are unclear. Understanding the vascular pathologies that cause microinfarcts may yield strategies to prevent their occurrence and reduce their deleterious effects on brain function. Current thinking suggests that cortical microinfarcts arise from the occlusion of penetrating arterioles, which are responsible for delivering oxygenated blood to small volumes of tissue. Unexpectedly, pre-clinical studies have shown that the occlusion of penetrating venules, which drain deoxygenated blood from cortex, lead to microinfarcts that appear identical to those resulting from arteriole occlusion. Here we discuss the idea that cerebral venule pathology could be an overlooked source for brain microinfarcts in humans. This article is part of the Special Issue "Vascular Dementia". Cover Image for this Issue: doi: 10.1111/jnc.14167.
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Affiliation(s)
- David A Hartmann
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Hyacinth I Hyacinth
- Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, Atlanta, Georgia, USA
| | - Francesca-Fang Liao
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Andy Y Shih
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA.,Center for Biomedical Imaging, Medical University of South Carolina, Charleston, South Carolina, USA
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Abstract
Clinical studies have revealed a strong link between increased burden of cerebral microinfarcts and risk for cognitive impairment. Since the sum of tissue damage incurred by microinfarcts is a miniscule percentage of total brain volume, we hypothesized that microinfarcts disrupt brain function beyond the injury site visible to histological or radiological examination. We tested this idea using a mouse model of microinfarcts, where single penetrating vessels that supply mouse cortex were occluded by targeted photothrombosis. We found that in vivo structural and diffusion MRI reliably reported the acute microinfarct core, based on spatial co-registrations with post-mortem stains of neuronal viability. Consistent with our hypothesis, c-Fos assays for neuronal activity and in vivo imaging of single vessel hemodynamics both reported functional deficits in viable peri-lesional tissues beyond the microinfarct core. We estimated that the volume of tissue with functional deficit in cortex was at least 12-fold greater than the volume of the microinfarct core. Impaired hemodynamic responses in peri-lesional tissues persisted at least 14 days, and were attributed to lasting deficits in neuronal circuitry or neurovascular coupling. These data show how individually miniscule microinfarcts could contribute to broader brain dysfunction during vascular cognitive impairment and dementia.
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Affiliation(s)
- Philipp M Summers
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - David A Hartmann
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Edward S Hui
- 2 Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong
| | - Xingju Nie
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Rachael L Deardorff
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Emilie T McKinnon
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Joseph A Helpern
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Jens H Jensen
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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Mateo C, Knutsen PM, Tsai PS, Shih AY, Kleinfeld D. Entrainment of Arteriole Vasomotor Fluctuations by Neural Activity Is a Basis of Blood-Oxygenation-Level-Dependent "Resting-State" Connectivity. Neuron 2017; 96:936-948.e3. [PMID: 29107517 DOI: 10.1016/j.neuron.2017.10.012] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 09/04/2017] [Accepted: 10/05/2017] [Indexed: 01/12/2023]
Abstract
Resting-state signals in blood-oxygenation-level-dependent (BOLD) imaging are used to parcellate brain regions and define "functional connections" between regions. Yet a physiological link between fluctuations in blood oxygenation with those in neuronal signaling pathways is missing. We present evidence from studies on mouse cortex that modulation of vasomotion, i.e., intrinsic ultra-slow (0.1 Hz) fluctuations in arteriole diameter, provides this link. First, ultra-slow fluctuations in neuronal signaling, which occur as an envelope over γ-band activity, entrains vasomotion. Second, optogenetic manipulations confirm that entrainment is unidirectional. Third, co-fluctuations in the diameter of pairs of arterioles within the same hemisphere diminish to chance for separations >1.4 mm. Yet the diameters of arterioles in distant (>5 mm), mirrored transhemispheric sites strongly co-fluctuate; these correlations are diminished in acallosal mice. Fourth, fluctuations in arteriole diameter coherently drive fluctuations in blood oxygenation. Thus, entrainment of vasomotion links neuronal pathways to functional connections.
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Affiliation(s)
- Celine Mateo
- Department of Physics, University of California, San Diego, La Jolla, CA, USA
| | - Per M Knutsen
- Department of Physics, University of California, San Diego, La Jolla, CA, USA
| | - Philbert S Tsai
- Department of Physics, University of California, San Diego, La Jolla, CA, USA
| | - Andy Y Shih
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - David Kleinfeld
- Department of Physics, University of California, San Diego, La Jolla, CA, USA; Section of Neurobiology, University of California, San Diego, La Jolla, CA, USA.
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48
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van Veluw SJ, Shih AY, Smith EE, Chen C, Schneider JA, Wardlaw JM, Greenberg SM, Biessels GJ. Detection, risk factors, and functional consequences of cerebral microinfarcts. Lancet Neurol 2017; 16:730-740. [PMID: 28716371 PMCID: PMC5861500 DOI: 10.1016/s1474-4422(17)30196-5] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 04/17/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023]
Abstract
Cerebral microinfarcts are small lesions that are presumed to be ischaemic. Despite the small size of these lesions, affected individuals can have hundreds to thousands of cerebral microinfarcts, which cause measurable disruption to structural brain connections, and are associated with dementia that is independent of Alzheimer's disease pathology or larger infarcts (ie, lacunar infarcts, and large cortical and non-lacunar subcortical infarcts). Substantial progress has been made with regard to understanding risk factors and functional consequences of cerebral microinfarcts, partly driven by new in-vivo detection methods and the development of animal models that closely mimic multiple aspects of cerebral microinfarcts in human beings. Evidence from these advances suggests that cerebral microinfarcts can be manifestations of both small vessel and large vessel disease, that cerebral microinfarcts are independently associated with cognitive impairment, and that these lesions are likely to cause damage to brain structure and function that extends beyond their actual lesion boundaries. Criteria for the identification of cerebral microinfarcts with in-vivo MRI are provided to support further studies of the association between these lesions and cerebrovascular disease and dementia.
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Affiliation(s)
- Susanne J van Veluw
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Eric E Smith
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Christopher Chen
- Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Steven M Greenberg
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Geert Jan Biessels
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands.
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49
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McKinnon ET, Fridriksson J, Glenn GR, Jensen JH, Helpern JA, Basilakos A, Rorden C, Shih AY, Spampinato MV, Bonilha L. Structural plasticity of the ventral stream and aphasia recovery. Ann Neurol 2017. [PMID: 28628946 DOI: 10.1002/ana.24983] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Restrengthening of the residual language network is likely to be crucial for speech recovery in poststroke aphasia. Eight participants with chronic aphasia received intensive speech therapy for 3 weeks, with standardized naming tests and brain magnetic resonance imaging before and after therapy. Kurtosis-based diffusion tensor tractography was used to measure mean kurtosis (MK) along a segment of the inferior longitudinal fasciculus (ILF). Therapy-related reduction in the number of semantic but not phonemic errors was associated with strengthening (renormalization) of ILF MK (r = -0.90, p < 0.05 corrected), suggesting that speech recovery is related to structural plasticity of language-specific components of the residual language network. Ann Neurol 2017;82:147-151.
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Affiliation(s)
- Emilie T McKinnon
- Department of Neurology, Medical University of South Carolina, Charleston, SC.,Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC.,Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Julius Fridriksson
- Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC
| | - G Russell Glenn
- Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC.,Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC.,Department of Neuroscience, Medical University of South Carolina, Charleston, SC
| | - Jens H Jensen
- Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC.,Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Joseph A Helpern
- Department of Neurology, Medical University of South Carolina, Charleston, SC.,Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC.,Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC.,Department of Neuroscience, Medical University of South Carolina, Charleston, SC
| | - Alexandra Basilakos
- Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC
| | - Chris Rorden
- Department of Psychology, University of South Carolina, Columbia, SC
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC
| | - M Vittoria Spampinato
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Leonardo Bonilha
- Department of Neurology, Medical University of South Carolina, Charleston, SC
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50
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Abstract
Photothrombosis of blood vessels refers to the activation of a circulating photosensitive dye with a green light to induce clotting in vivo (Watson et al., 1985). Previous studies have described how a focused green laser could be used to noninvasively occlude pial arterioles and venules at the brain surface (Schaffer et al., 2006; Nishimura et al., 2007; Shih et al., 2013). Here we show that small regions of the capillary bed can similarly be occluded to study the ischemic response within the capillary system of the mouse cerebral cortex. The advantage of this approach is that the ischemic zone is restricted to a diameter of approximately 150-250 μm. This permits higher quality two-photon imaging of degenerative processes that would be otherwise difficult to visualize with models of large-scale stroke, due to excessive photon scattering. A consequence of capillary occlusion is leakage of the blood-brain barrier (BBB). Here, through the use of two-photon imaging data sets, we show how to quantify capillary leakage by determining the spatial extent and localization of intravenous dye extravasation.
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Affiliation(s)
- Robert G Underly
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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