scholarly journals Ion channel networks in the control of cerebral blood flow

2015 ◽  
Vol 36 (3) ◽  
pp. 492-512 ◽  
Author(s):  
Thomas A Longden ◽  
David C Hill-Eubanks ◽  
Mark T Nelson
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Smooth Muscle ◽  
Cerebral Blood Flow ◽  
Ion Channels ◽  
Ion Channel ◽  
Vascular Endothelial Cells ◽  
Neurovascular Unit ◽  
Muscle Membrane ◽  
Neuronal Stimulation

One hundred and twenty five years ago, Roy and Sherrington made the seminal observation that neuronal stimulation evokes an increase in cerebral blood flow.1 Since this discovery, researchers have attempted to uncover how the cells of the neurovascular unit—neurons, astrocytes, vascular smooth muscle cells, vascular endothelial cells and pericytes—coordinate their activity to control this phenomenon. Recent work has revealed that ionic fluxes through a diverse array of ion channel species allow the cells of the neurovascular unit to engage in multicellular signaling processes that dictate local hemodynamics. In this review we center our discussion on two major themes: (1) the roles of ion channels in the dynamic modulation of parenchymal arteriole smooth muscle membrane potential, which is central to the control of arteriolar diameter and therefore must be harnessed to permit changes in downstream cerebral blood flow, and (2) the striking similarities in the ion channel complements employed in astrocytic endfeet and endothelial cells, enabling dual control of smooth muscle from either side of the blood–brain barrier. We conclude with a discussion of the emerging roles of pericyte and capillary endothelial cell ion channels in neurovascular coupling, which will provide fertile ground for future breakthroughs in the field.

scholarly journals Circulating tPA contributes to neurovascular coupling by a mechanism involving the endothelial NMDA receptors

2019 ◽  
Vol 40 (10) ◽  
pp. 2038-2054 ◽  
Author(s):  
Antoine Anfray ◽  
Antoine Drieu ◽  
Vincent Hingot ◽  
Yannick Hommet ◽  
Mervé Yetim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Neurovascular Unit ◽  
Neurovascular Coupling ◽  
Laser Speckle ◽  
Tissue Type ◽  
Blood Flow Increase ◽  
The Brain

The increase of cerebral blood flow evoked by neuronal activity is essential to ensure enough energy supply to the brain. In the neurovascular unit, endothelial cells are ideally placed to regulate key neurovascular functions of the brain. Nevertheless, some outstanding questions remain about their exact role neurovascular coupling (NVC). Here, we postulated that the tissue-type plasminogen activator (tPA) present in the circulation might contribute to NVC by a mechanism dependent of its interaction with endothelial N-Methyl-D-Aspartate Receptor (NMDAR). To address this question, we used pharmacological and genetic approaches to interfere with vascular tPA-dependent NMDAR signaling, combined with laser speckle flowmetry, intravital microscopy and ultrafast functional ultrasound in vivo imaging. We found that the tPA present in the blood circulation is capable of potentiating the cerebral blood flow increase induced by the activation of the mouse somatosensorial cortex, and that this effect is mediated by a tPA-dependent activation of NMDAR expressed at the luminal part of endothelial cells of arteries. Although blood molecules, such as acetylcholine, bradykinin or ATP are known to regulate vascular tone and induce vessel dilation, our present data provide the first evidence that circulating tPA is capable of influencing neurovascular coupling (NVC).

Telmisartan prevents high-fat diet-induced neurovascular impairments and reduces anxiety-like behavior

2021 ◽  
pp. 0271678X2110034
Author(s):  
Gianna Huber ◽  
Mikolaj Ogrodnik ◽  
Jan Wenzel ◽  
Ines Stölting ◽  
Lukas Huber ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
High Fat Diet ◽  
Neurovascular Unit ◽  
Laser Speckle ◽  
Angiotensin Ii Receptor ◽  
High Fat ◽  
Diet Induced Obesity ◽  
Whisker Pad ◽  
Receptor Blockers

Angiotensin II receptor blockers (telmisartan) prevent rodents from diet-induced obesity and improve their metabolic status. Hyperglycemia and obesity are associated with reduced cerebral blood flow and neurovascular uncoupling which may lead to behavioral deficits. We wanted to know whether a treatment with telmisartan prevents these changes in obesity. We put young mice on high-fat diet and simultaneously treated them with telmisartan. At the end of treatment, we performed laser speckle imaging and magnetic resonance imaging to assess the effect on neurovascular coupling and cerebral blood flow. Different behavioral tests were used to investigate cognitive function. Mice developed diet-induced obesity and after 16, not 8 weeks of high-fat diet, however, the response to whisker pad stimulation was about 30% lower in obese compared to lean mice. Simultaneous telmisartan treatment increased the response again by 10% compared to obese mice. Moreover, telmisartan treatment normalized high-fat diet-induced reduction of cerebral blood flow and prevented a diet-induced anxiety-like behavior. In addition to that, telmisartan affects cellular senescence and string vessel formation in obesity. We conclude, that telmisartan protects against neurovascular unit impairments in a diet-induced obesity setting and may play a role in preventing obesity related cognitive deficits in Alzheimer’s disease.

Abstract MP17: Upregulating E2F1 Mitigates Senescence-Associated Phenotypes in Cultured Primary Endothelial Cells

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Michael E Maniskas ◽  
Yun-ju Lai ◽  
Sean P Marrelli ◽  
Louise D McCullough ◽  
Jose F Moruno-manchon
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Neurovascular Unit ◽  
Glucose Deprivation ◽  
Cerebral Hypoperfusion ◽  
Aged Mouse ◽  
Aged Mice ◽  
Brain Vasculature ◽  
Bilateral Carotid ◽  
The Brain

Vascular contributions to cognitive impairment and dementia (VCID) includes multiple disorders that are identified by cognitive deficits secondary to cerebrovascular pathology. The risk of VCID is higher in people after the age of 70, and, currently, there is no effective treatment. Vascular endothelial cells (VEC) are critical components of the brain vasculature and neurovascular unit and their health is vital to the capacity of the brain vasculature to respond to stressors. However, aged VEC may enter an irreversible replicative-arrest state (senescence), which has been associated with dementia. E2F transcription factor 1 (E2F1) regulates cell cycle progression and DNA damage repair. Importantly, E2F1 deficiency is associated with cell senescence. We hypothesized that E2F1 downregulation contributes to senescence in the cerebral endothelium during aging. We used cultured primary VEC from young (4-months old, mo) and aged (18-mo) male and female mice for RNA sequencing, plasmid-based gene delivery, high-resolution microscopy, and (4-, 12-, and 18-mo) mice of the bilateral carotid artery stenosis (BCAS) model, which produces chronic cerebral hypoperfusion and recapitulates some of the features seen in patients with VCID. We found that overexpression of E2F1 reduced the levels of senescence-associated phenotypes in cultured VEC from young mice that were exposed to oxygen and glucose deprivation (p<0.001), which induces endothelial senescence. Our RNA seq data showed that the expression of E2f1 was reduced (~40%) in cultured primary VEC from aged mouse brains compared with young cells (p<0.001). E2F1 levels were reduced in the brains of aged mice. Interestingly, we found sex differences in E2F1 levels, with less protein levels (~30%) in males vs females (p<0.05), independently of age. Also, aged BCAS mice (1 month after surgery) had more severe senescence phenotypes, reduced cerebral blood flow, and worse memory deficits compared with control mice (p<0.05). The effect of BCAS was more prominent in aged mice compared with younger (4- and 12-mo) mice. In conclusion , our study identifies E2F1 as a potential regulator of endothelial senescence in mice and highlights the contribution of aging as an important factor in losing endothelial resilience.

scholarly journals Electro-Metabolic Sensing Through Capillary ATP-Sensitive K+ Channels and Adenosine to Control Cerebral Blood Flow

2021 ◽  
Author(s):  
Maria Sancho ◽  
Nicholas R. Klug ◽  
Amreen Mughal ◽  
Thomas J. Heppner ◽  
David Hill-Eubanks ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Vascular Function ◽  
Brain Activity ◽  
List Type ◽  
Capillary Endothelial Cells ◽  
Metabolic Sensing ◽  
Cellular Components

SUMMARYThe dense network of capillaries composed of capillary endothelial cells (cECs) and pericytes lies in close proximity to all neurons, ideally positioning it to sense neuro/glial-derived compounds that regulate regional and global cerebral perfusion. The membrane potential (VM) of vascular cells serves as the essential output in this scenario, linking brain activity to vascular function. The ATP-sensitive K+ channel (KATP) is a key regulator of vascular VM in other beds, but whether brain capillaries possess functional KATP channels remains unknown. Here, we demonstrate that brain capillary ECs and pericytes express KATP channels that robustly control VM. We further show that the endogenous mediator adenosine acts through A2A receptors and the Gs/cAMP/PKA pathway to activate capillary KATP channels. Moreover, KATP channel stimulation in vivo causes vasodilation and increases cerebral blood flow (CBF). These findings establish the presence of KATP channels in cECs and pericytes and suggest their significant influence on CBF.HIGHLIGHTSCapillary network cellular components—endothelial cells and pericytes—possess functional KATP channels.Activation of KATP channels causes profound hyperpolarization of capillary cell membranes.Capillary KATP channels are activated by exogenous adenosine via A2A receptors and cAMP-dependent protein kinase.KATP channel activation by adenosine or synthetic openers increases cerebral blood flow.

scholarly journals Inhibitory effect of caveolin-1 in vascular endothelial cells, pericytes and smooth muscle cells

Oncotarget ◽  
2017 ◽  
Vol 8 (44) ◽  
pp. 76165-76173 ◽  
Author(s):  
Hongping Xu ◽  
Liwei Zhang ◽  
Wei Chen ◽  
Jiazhou Xu ◽  
Ruting Zhang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Endothelial Cells ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Vascular Endothelial ◽  
Caveolin 1

Microvascular dilation in response to occlusion: a coordinating role for conducted vasomotor responses

2000 ◽  
Vol 279 (1) ◽  
pp. H279-H284 ◽  
Author(s):  
Kim A. Dora ◽  
David N. Damon ◽  
Brian R. Duling
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Shear Stress ◽  
Smooth Muscle ◽  
Third Order ◽  
Vasomotor Responses ◽  
Vasodilatory Response ◽  
Flow Through ◽  
Stress Dependent ◽  
Dependent Mechanism

In rat cremasteric microcirculation, mechanical occlusion of one branch of an arteriolar bifurcation causes an increase in flow and vasodilation of the unoccluded daughter branch. This dilation has been attributed to the operation of a shear stress-dependent mechanism in the microcirculation. Instead of or in addition to this, we hypothesized that the dilation observed during occlusion is the result of a conducted signal originating distal to the occlusion. To test this hypothesis, we blocked the ascending spread of conducted vasomotor responses by damaging the smooth muscle and endothelial cells in a 200-μm segment of second- or third-order arterioles. We found that a conduction blockade eliminated or diminished the occlusion-associated increase in flow through the unoccluded branch and abolished or strongly attenuated the vasodilatory response in both vessels at the branch. We also noted that vasodilations induced by ACh (10−4 M, 0.6 s) spread to, but not beyond, the area of damage. Taken together, these data provide strong evidence that conducted vasomotor responses have an important role in coordinating blood flow in response to an arteriolar occlusion.

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