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In Vitro Model for Ischemic Stroke: Functional Analysis of Vascular Smooth Muscle Cells. Cell Mol Neurobiol 2021; 42:2289-2304. [PMID: 34032948 DOI: 10.1007/s10571-021-01103-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/17/2021] [Indexed: 10/21/2022]
Abstract
The Neurovascular Unit (NVU) is formed by vascular and neural cells controlling the cerebral hyperaemia. All the components are anatomically and functionally linked to each other, resulting in a highly efficient regulation of the cerebral blood flow, which, when interrupted, can lead to stroke. An ischemic stroke (IS) is the most common type of stroke with high rates of morbidity, mortality and disability. Therefore, it is of extreme importance to protect the functional and structural integrity of the NVU in patients with IS, understanding the mechanisms involved and how it affects each component of the NVU. Thus, the aim of this work is to analyse how the vascular smooth muscle cells from the rat middle cerebral artery function/react after an ischemic event. To mimic this event, primary cortical cultures were challenged to oxygen and glucose deprivation (OGD) for 4 h and 6 h, and the smooth muscle cells (SMCs) contractility was analysed after exposure to different media previously conditioned by the cortical cultures upon reperfusion. The results show a dual effect on the SMCs response to the vasorelaxant agent, only for cells exposed to the reperfusion media conditioned by neuron-glia cultures challenged by OGD, leading to increased relaxation of the SMCs for OGD 4 h, whereas for OGD 6 h the effect is reversed leading to contraction of the SMCs. These differences demonstrate that the astrocytes mediate the vasoactive response of vascular smooth muscle by releasing factors into the reperfusion medium, and the hypoxia time is fundamental for a beneficial/harmful response by the vascular smooth muscle.
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Quelhas P, Baltazar G, Cairrao E. The Neurovascular Unit: Focus on the Regulation of Arterial Smooth Muscle Cells. Curr Neurovasc Res 2020; 16:502-515. [PMID: 31738142 DOI: 10.2174/1567202616666191026122642] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/01/2019] [Accepted: 09/20/2019] [Indexed: 02/08/2023]
Abstract
The neurovascular unit is a physiological unit present in the brain, which is constituted by elements of the nervous system (neurons and astrocytes) and the vascular system (endothelial and mural cells). This unit is responsible for the homeostasis and regulation of cerebral blood flow. There are two major types of mural cells in the brain, pericytes and smooth muscle cells. At the arterial level, smooth muscle cells are the main components that wrap around the outside of cerebral blood vessels and the major contributors to basal tone maintenance, blood pressure and blood flow distribution. They present several mechanisms by which they regulate both vasodilation and vasoconstriction of cerebral blood vessels and their regulation becomes even more important in situations of injury or pathology. In this review, we discuss the main regulatory mechanisms of brain smooth muscle cells and their contributions to the correct brain homeostasis.
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Affiliation(s)
- Patrícia Quelhas
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
| | - Graça Baltazar
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
| | - Elisa Cairrao
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
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Shvetsova AA, Gaynullina DK, Schmidt N, Bugert P, Lukoshkova EV, Tarasova OS, Schubert R. TASK-1 channel blockade by AVE1231 increases vasocontractile responses and BP in 1- to 2-week-old but not adult rats. Br J Pharmacol 2020; 177:5148-5162. [PMID: 32860629 PMCID: PMC7589011 DOI: 10.1111/bph.15249] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 08/14/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022] Open
Abstract
Background and Purpose The vasomotor role of K2P potassium channels during early postnatal development has never been investigated. We tested the hypothesis that TASK‐1 channel (K2P family member) contribution to arterial vascular tone and BP is higher in the early postnatal period than in adulthood. Experimental Approach We studied 10‐ to 15‐day‐old (“young”) and 2‐ to 3‐month‐old (“adult”) male rats performing digital PCR (dPCR) (using endothelium‐intact saphenous arteries), isometric myography, sharp microelectrode technique, quantitative PCR (qPCR) and Western blotting (using endothelium‐denuded saphenous arteries), and arterial pressure measurements under urethane anaesthesia. Key Results We found mRNA of Kcnk1–Kcnk7, Kcnk12, and Kcnk13 genes to be expressed in rat saphenous artery, and Kcnk3 (TASK‐1) and Kcnk6 (TWIK‐2) were most abundant in both age groups. The TASK‐1 channel blocker AVE1231 (1 μmol·L−1) prominently depolarized arterial smooth muscle and increased basal tone level and contractile responses to methoxamine of arteries from young rats but had almost no effect in adult rats. The level of TASK‐1 mRNA and protein expression was higher in arteries from young compared with adult rats. Importantly, intravenous administration of AVE1231 (4 mg·kg−1) had no effect on mean arterial pressure in adult rats but prominently raised it in young rats. Conclusion and Implications We showed that TASK‐1 channels are important for negative feedback regulation of vasocontraction in young but not adult rats. The influence of TASK‐1 channels most likely contributes to low BP level at perinatal age.
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Affiliation(s)
- Anastasia A Shvetsova
- Centre for Biomedicine and Medical Technology Mannheim (CBTM) and European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Dina K Gaynullina
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Nadine Schmidt
- Centre for Biomedicine and Medical Technology Mannheim (CBTM) and European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Peter Bugert
- Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, German Red Cross Blood Service Baden-Württemberg-Hessen, Mannheim, Germany
| | - Elena V Lukoshkova
- Institute of Experimental Cardiology, National Medical Research Center of Cardiology, Moscow, Russia
| | - Olga S Tarasova
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia.,State Research Center of the Russian Federation-Institute for Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Rudolf Schubert
- Centre for Biomedicine and Medical Technology Mannheim (CBTM) and European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,Physiology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
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Nasr IW, Chun Y, Kannan S. Neuroimmune responses in the developing brain following traumatic brain injury. Exp Neurol 2019; 320:112957. [PMID: 31108085 DOI: 10.1016/j.expneurol.2019.112957] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 05/10/2019] [Accepted: 05/15/2019] [Indexed: 12/26/2022]
Abstract
Traumatic brain injury (TBI) is one of the leading causes of both acute and long-term morbidity in the pediatric population, leading to a substantial, long-term socioeconomic burden. Despite the increase in the amount of pre-clinical and clinical research, treatment options for TBI rely heavily on supportive care with very limited targeted interventions that improve the acute and chronic sequelae of TBI. Other than injury prevention, not much can be done to limit the primary injury, which consists of tissue damage and cellular destruction. Secondary injury is the result of the ongoing complex inflammatory pathways that further exacerbate tissue damage, resulting in the devastating chronic outcomes of TBI. On the other hand, some level of inflammation is essential for neuronal regeneration and tissue repair. In this review article we discuss the various stages of the neuroimmune response in the immature, pediatric brain in the context of normal maturation and development of the immune system. The developing brain has unique features that distinguish it from the adult brain, and the immune system plays an integral role in CNS development. Those features could potentially make the developing brain more susceptible to worse outcomes, both acutely and in the long-term. The neuroinflammatory reaction which is triggered by TBI can be described as a highly intricate interaction between the cells of the innate and the adaptive immune systems. The innate immune system is triggered by non-specific danger signals that are released from damaged cells and tissues, which in turn leads to neutrophil infiltration, activation of microglia and astrocytes, complement release, as well as histamine release by mast cells. The adaptive immune response is subsequently activated leading to the more chronic effects of neuroinflammation. We will also discuss current attempts at modulating the TBI-induced neuroinflammatory response. A better understanding of the role of the immune system in normal brain development and how immune function changes with age is crucial for designing therapies to appropriately target the immune responses following TBI in order to enhance repair and plasticity.
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Affiliation(s)
- Isam W Nasr
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States of America
| | - Young Chun
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States of America
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States of America.
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Shvetsova AA, Gaynullina DK, Tarasova OS, Schubert R. Negative feedback regulation of vasocontraction by potassium channels in 10- to 15-day-old rats: Dominating role of K v 7 channels. Acta Physiol (Oxf) 2019; 225:e13176. [PMID: 30136434 DOI: 10.1111/apha.13176] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/11/2018] [Accepted: 08/20/2018] [Indexed: 12/26/2022]
Abstract
AIM Potassium channels are key regulators of smooth muscle membrane potential and arterial tone. However, the roles of potassium channels in vascular tone regulation in the systemic circulation during early postnatal development are poorly understood. Therefore, this study tested the hypothesis that the negative feedback regulation of vasocontraction by potassium channels changes during maturation. METHODS Experiments were performed on endothelium-denuded saphenous arteries from 10- to 15-day-old and 2- to 3-month-old male rats. Isometric force and membrane potential were recorded using wire myography and the sharp microelectrode technique respectively; mRNA and protein contents were determined by qPCR and Western blotting. RESULTS The effects of Kv 1, Kir and Kv 7 channel blockers (DPO-1, BaCl2 , XE991) on methoxamine-induced contraction were larger in arteries of 10- to 15-day-old compared to 2- to 3-month-old animals. In contrast, the BKC a channel blocker iberiotoxin had a stronger influence in 2- to 3- month-old rats. The effects of KATP and Kv 2 channel blockers (glibenclamide, stromatoxin) were not pronounced at both ages. The larger influence of Kv 7 and Kir channel blockade on arterial contraction in 10- to 15-day-old rats was associated with more prominent smooth muscle depolarization. The developmental alterations in potassium channel functioning were generally consistent with their mRNA and protein expression levels in arterial smooth muscle. CONCLUSION The negative feedback regulation of vasocontraction by potassium channels varies during maturation depending on the channel type. A dominating contribution of Kv 7 channels to the regulation of basal tone and agonist-induced contraction was observed in arteries of 10- to 15-day-old animals.
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Affiliation(s)
- Anastasia A. Shvetsova
- Centre for Biomedicine and Medical Technology Mannheim (CBTM); European Center of Angioscience (ECAS); Research Division Cardiovascular Physiology; Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
- State Research Center of the Russian Federation - Institute for Biomedical Problems; Russian Academy of Sciences; Moscow Russia
| | - Dina K. Gaynullina
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
- State Research Center of the Russian Federation - Institute for Biomedical Problems; Russian Academy of Sciences; Moscow Russia
- Department of Physiology; Russian National Research Medical University; Moscow Russia
| | - Olga S. Tarasova
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
- State Research Center of the Russian Federation - Institute for Biomedical Problems; Russian Academy of Sciences; Moscow Russia
| | - Rudolf Schubert
- Centre for Biomedicine and Medical Technology Mannheim (CBTM); European Center of Angioscience (ECAS); Research Division Cardiovascular Physiology; Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
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Dang YX, Shi KN, Wang XM. Early Changes in Glutamate Metabolism and Perfusion in Basal Ganglia following Hypoxia-Ischemia in Neonatal Piglets: A Multi-Sequence 3.0T MR Study. Front Physiol 2017; 8:237. [PMID: 28487658 PMCID: PMC5404207 DOI: 10.3389/fphys.2017.00237] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/05/2017] [Indexed: 12/20/2022] Open
Abstract
The excitotoxicity of glutamate metabolism as well as hemodynamic disorders of the brain are both risk factors for neonatal hypoxic–ischemic brain damage (HIBD). In the present study, changes in glutamate metabolism in the basal ganglia were detected by proton magnetic resonance spectroscopy (1H-MRS) at 0–6, 8–12, 24–30, and 48–60 h after the induction of hypoxia-ischemia (HI) in newborn piglets. Meanwhile, correlation analysis was performed by combining the microcirculatory perfusion informations acquired by intravoxel incoherent motion (IVIM) scan to explore their possible interaction mechanism. The results suggested that Glu level in the basal ganglia underwent a “two-phase” change after HI; perfusion fraction f, an IVIM-derived perfusion parameter, was clearly decreased in the early stage after HI, then demonstrated a transient and slight recovery process, and thereafter continued to decrease. The changes in f and Glu level were in a significant negative correlation (r = −0.643, P = 0.001). Our study results revealed that Glu level is closely associated with the microcirculatory perfusion changes in the acute stage of HIBD.
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Affiliation(s)
- Yu-Xue Dang
- Department of Radiology, Shengjing Hospital of China Medical UniversityShenyang, China
| | - Kai-Ning Shi
- Department of Imaging Systems Clinical Science, Philips HealthcareBeijing, China
| | - Xiao-Ming Wang
- Department of Radiology, Shengjing Hospital of China Medical UniversityShenyang, China
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Reho JJ, Fisher SA. The stress of maternal separation causes misprogramming in the postnatal maturation of rat resistance arteries. Am J Physiol Heart Circ Physiol 2015; 309:H1468-78. [PMID: 26371173 DOI: 10.1152/ajpheart.00567.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/03/2015] [Indexed: 11/22/2022]
Abstract
We examined the effect of stress in the first 2 wk of life induced by brief periods of daily maternal separation on developmental programming of rat small resistance mesenteric arteries (MAs). In MAs of littermate controls, mRNAs encoding mediators of vasoconstriction, including the α1a-adrenergic receptor, smooth muscle myosin heavy chain, and CPI-17, the inhibitory subunit of myosin phosphatase, increased from after birth through sexual [postnatal day (PND) 35] and full maturity, up to ∼80-fold, as measured by quantitative PCR. This was commensurate with two- to fivefold increases in maximum force production to KCl depolarization, calcium, and the α-adrenergic agonist phenylephrine, and increasing systolic blood pressure. Rats exposed to maternal separation stress as neonates had markedly accelerated trajectories of maturation of arterial contractile gene expression and function measured at PND14 or PND21 (weaning), 1 wk after the end of the stress protocol. This was suppressed by the α-adrenergic receptor blocker terazosin (0.5 mg·kg ip(-1)·day(-1)), indicating dependence on stress activation of sympathetic signaling. Due to the continued maturation of MAs in control rats, by sexual maturity (PND35) and into adulthood, no differences were observed in arterial function or response to a second stressor in rats stressed as neonates. Thus early life stress misprograms resistance artery smooth muscle, increasing vasoconstrictor function and blood pressure. This effect wanes in later stages, suggesting plasticity during arterial maturation. Further studies are indicated to determine whether stress in different periods of arterial maturation may cause misprogramming persisting through maturity and the potential salutary effect of α-adrenergic blockade in suppression of this response.
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Affiliation(s)
- John J Reho
- Departments of Medicine (Cardiovascular Medicine) and Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Steven A Fisher
- Departments of Medicine (Cardiovascular Medicine) and Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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Reho JJ, Zheng X, Benjamin JE, Fisher SA. Neural programming of mesenteric and renal arteries. Am J Physiol Heart Circ Physiol 2015; 307:H563-73. [PMID: 24929853 DOI: 10.1152/ajpheart.00250.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is evidence for developmental origins of vascular dysfunction yet little understanding of maturation of vascular smooth muscle (VSM) of regional circulations. We measured maturational changes in expression of myosin phosphatase (MP) and the broader VSM gene program in relation to mesenteric small resistance artery (SRA) function. We then tested the role of the sympathetic nervous system (SNS) in programming of SRAs and used genetically engineered mice to define the role of MP isoforms in the functional maturation of the mesenteric circulation. Maturation of rat mesenteric SRAs as measured by qPCR and immunoblotting begins after the second postnatal week and is not complete until maturity. It is characterized by induction of markers of VSM differentiation (smMHC, γ-, α-actin), CPI-17, an inhibitory subunit of MP and a key target of α-adrenergic vasoconstriction, α1-adrenergic, purinergic X1, and neuropeptide Y1 receptors of sympathetic signaling. Functional correlates include maturational increases in α-adrenergic-mediated force and calcium sensitization of force production (MP inhibition) measured in first-order mesenteric arteries ex vivo. The MP regulatory subunit Mypt1 E24+/LZ- isoform is specifically upregulated in SRAs during maturation. Conditional deletion of mouse Mypt1 E24 demonstrates that splicing of E24 causes the maturational reduction in sensitivity to cGMP-mediated vasorelaxation (MP activation). Neonatal chemical sympathectomy (6-hydroxydopamine) suppresses maturation of SRAs with minimal effect on a conduit artery. Mechanical denervation of the mature rat renal artery causes a reversion to the immature gene program. We conclude that the SNS captures control of the mesenteric circulation by programming maturation of the SRA smooth muscle.
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