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Magyar-Stang R, Pál H, Csányi B, Gaál A, Mihály Z, Czinege Z, Csipo T, Ungvari Z, Sótonyi P, Varga A, Horváth T, Bereczki D, Koller A, Debreczeni R. Assessment of cerebral autoregulatory function and inter-hemispheric blood flow in older adults with internal carotid artery stenosis using transcranial Doppler sonography-based measurement of transient hyperemic response after carotid artery compression. GeroScience 2023; 45:3333-3357. [PMID: 37599343 PMCID: PMC10643517 DOI: 10.1007/s11357-023-00896-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/16/2023] [Indexed: 08/22/2023] Open
Abstract
Unhealthy vascular aging promotes atherogenesis, which may lead to significant internal carotid artery stenosis (CAS) in 5 to 7.5% of older adults. The pathogenic factors that promote accelerated vascular aging and CAS also affect the downstream portion of the cerebral microcirculation in these patients. Primary treatments of significant CAS are eversion endarterectomy or endarterectomy with patch plasty. Factors that determine adequate hemodynamic compensation and thereby the clinical consequences of CAS as well as medical and surgical complications of carotid reconstruction surgery likely involve the anatomy of the circle of Willis (CoW), the magnitude of compensatory inter-hemispheric blood flow, and the effectiveness of cerebral microcirculatory blood flow autoregulation. This study aimed to test two hypotheses based on this theory. First, we hypothesized that patients with symptomatic and asymptomatic CAS would exhibit differences in autoregulatory function and inter-hemispheric blood flow. Second, we predicted that anatomically compromised CoW would associate with impaired inter-hemispheric blood flow compensation. We enrolled older adults with symptomatic or asymptomatic internal CAS (>70% NASCET criteria; n = 46) and assessed CoW integrity by CT angiography. We evaluated transient hyperemic responses in the middle cerebral arteries (MCA) after common carotid artery compression (CCC; 10 s) by transcranial Doppler sonography (TCD). We compared parameters reflecting autoregulatory function (e.g., transient hyperemic response ratio [THRR], return to baseline time [RTB], changes of vascular resistance) and inter-hemispheric blood flow (residual blood flow velocity). Our findings revealed that CAS was associated with impaired cerebral vascular reactivity. However, we did not observe significant differences in autoregulatory function or inter-hemispheric blood flow between patients with symptomatic and asymptomatic CAS. Moreover, anatomically compromised CoW did not significantly affect these parameters. Notably, we observed an inverse correlation between RTB and THRR, and 49% of CAS patients exhibited a delayed THRR, which associated with decreased inter-hemispheric blood flow. Future studies should investigate how TCD-based evaluation of autoregulatory function and inter-hemispheric blood flow can be used to optimize surgical techniques and patient selection for internal carotid artery revascularization.
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Affiliation(s)
- Rita Magyar-Stang
- Department of Neurology, Semmelweis University, Budapest, Hungary.
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary.
| | - Hanga Pál
- Department of Neurology, Semmelweis University, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Borbála Csányi
- Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Anna Gaál
- Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Zsuzsanna Mihály
- Department of Vascular and Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Zsófia Czinege
- Department of Vascular and Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Tamas Csipo
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 731042, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 731042, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Peggy and Charles Stephenson Cancer Center, Oklahoma City, OK, 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Péter Sótonyi
- Department of Vascular and Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Andrea Varga
- Department of Diagnostic Radiology, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Tamás Horváth
- Research Center for Sport Physiology, Hungarian University of Sports Science, Budapest, Hungary
| | - Dániel Bereczki
- Department of Neurology, Semmelweis University, Budapest, Hungary
| | - Akos Koller
- Research Center for Sport Physiology, Hungarian University of Sports Science, Budapest, Hungary
- Department of Morphology & Physiology, Faculty of Health Sciences, and Translational Medicine Institute, Faculty of Medicine, and ELKH-SE, Cerebrovascular and Neurocognitive Disorders Research Group, Semmelweis University, Budapest, Hungary
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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Ladthavorlaphatt K, Surti FBS, Beishon LC, Panerai RB, Robinson TG. Challenging neurovascular coupling through complex and variable duration cognitive paradigms: A subcomponent analysis. Med Eng Phys 2022; 110:103921. [PMID: 36564144 DOI: 10.1016/j.medengphy.2022.103921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/04/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022]
Abstract
A similar pattern of cerebral blood velocity (CBv) response has been observed for neurovascular coupling (NVC) assessment with cognitive tasks of varying complexity and duration. This lack of specificity could result from parallel changes in arterial blood pressure (BP) and PaCO2, which could confound the estimates of NVC integrity. Healthy participants (n = 16) underwent recordings at rest (5 min sitting) and during randomized paradigms of different complexity (naming words (NW) beginning with P-, R-, V- words and serial subtractions (SS) of 100-2, 100-7, 1000-17, with durations of 5, 30 and 60 s). Bilateral CBv (middle cerebral arteries, transcranial Doppler), end-tidal CO2 (EtCO2, capnography), blood pressure (BP, Finapres) and heart rate (HR, ECG) were recorded continuously. The bilateral CBv response to all paradigms was classified under objective criteria to select only responders, then the repeated data were averaged between visits. Bilateral CBv change to tasks was decomposed into the relative contributions (subcomponents) of arterial BP (VBP; neurogenic), critical closing pressure (VCrCP; metabolic) and resistance area product (VRAP; myogenic). A temporal effect was demonstrated in bilateral VBP and VRAP during all tasks (p<0.002), increased VBP early (between 0 and 10 s) and followed by decreases of VRAP late (25-35 s) in the response. VCrCP varied by complexity and duration (p<0.046). The main contributions to CBv responses to cognitive tasks of different complexity and duration were VBP and VRAP, whilst a smaller contribution from VCrCP would suggest sensitivity to metabolic demands. Further studies are needed to assess the influence of different paradigms, ageing and cerebrovascular conditions.
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Affiliation(s)
- Kannaphob Ladthavorlaphatt
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; Medical Diagnostics Unit, Thammasat University Hospital, Thammasat University, Pathumthani, Thailand.
| | - Farhaana B S Surti
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom
| | - Lucy C Beishon
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
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Morse CJ, Boerman EM, McDonald MW, Padilla J, Olver TD. The role of nitric oxide in flow-induced and myogenic responses in 1A, 2A, and 3A branches of the porcine middle cerebral artery. J Appl Physiol (1985) 2022; 133:1228-1236. [PMID: 36227166 PMCID: PMC9715271 DOI: 10.1152/japplphysiol.00209.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/13/2022] [Accepted: 10/09/2022] [Indexed: 12/15/2022] Open
Abstract
Myogenic and flow-induced reactivity contribute to cerebral autoregulation, with potentially divergent roles for smaller versus larger arteries. The present study tested the hypotheses that compared with first-order (1A) branches of the middle cerebral artery, second- and third-order branches (2A and 3A, respectively) exhibit greater myogenic reactivity but reduced flow-induced constriction. Furthermore, nitric oxide synthase (NOS) inhibition may amplify myogenic reactivity and abolish instances of flow-induced dilation. Isolated porcine cerebral arteries mounted in a pressure myograph were exposed to incremental increases in intraluminal pressure (40-120 mmHg; n = 41) or flow (1-1,170 µL/min; n = 31). Intraluminal flows were adjusted to achieve 5, 10, 20, and 40 dyn/cm2 of wall shear stress at 60 mmHg. Myogenic tone was greater in 3A versus 1A arteries (P < 0.05). There was an inverse relationship between myogenic reactivity and passive arterial diameter (P < 0.01). NOS inhibition increased basal tone to a lesser extent in 3A versus 1A arteries (P < 0.01) but did not influence myogenic reactivity (P = 0.49). Increasing flow decreased luminal diameter (P ≤ 0.01), with increased vasoconstriction at 10-40 dyn/cm2 of shear stress (P < 0.01). However, relative responses were similar between 1A, 2A, and 3A arteries (P = 0.40) with and without NOS inhibition conditions (P ≥ 0.29). Whereas NOS inhibition increases basal myogenic tone, and myogenic reactivity was less in smaller versus larger arteries (range = ∼100-550 µM), neither NOS inhibition nor luminal diameter influences flow-induced constriction in porcine cerebral arteries.NEW & NOTEWORTHY This study demonstrated size-dependent heterogeneity in myogenic reactivity in porcine cerebral arteries. Smaller branches of the middle cerebral artery exhibited increased myogenic reactivity, but attenuated NOS-dependent increases in myogenic tone compared with larger branches. Flow-dependent regulation does not exhibit the same variation; diameter-independent flow-induced vasoconstrictions occur across all branch orders and are not affected by NOS inhibition. Conceptually, flow-induced vasoconstriction contributes to cerebral autoregulation, particularly in larger arteries with low myogenic tone.
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Affiliation(s)
- Cameron J Morse
- Department Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Erika M Boerman
- Department Medical Physiology and Pharmacology, University of Missouri, Columbia, Missouri
| | - Matthew W McDonald
- Department Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jaume Padilla
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
- Department Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - T Dylan Olver
- Department Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Association of cerebral microvascular dysfunction and white matter injury in Alzheimer's disease. GeroScience 2022; 44:1-14. [PMID: 35612774 PMCID: PMC9617002 DOI: 10.1007/s11357-022-00585-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/05/2022] [Indexed: 12/23/2022] Open
Abstract
Patients with Alzheimer's disease (AD) often have cerebral white matter (WM) hyperintensities on MRI and microinfarcts of presumed microvascular origin pathologically. Here, we determined if vasodilator dysfunction of WM-penetrating arterioles is associated with pathologically defined WM injury and disturbances in quantitative MRI-defined WM integrity in patients with mixed microvascular and AD pathology. We analyzed tissues from 28 serially collected human brains from research donors diagnosed with varying degrees of AD neuropathologic change (ADNC) with or without cerebral microinfarcts (mVBI). WM-penetrating and pial surface arteriolar responses to the endothelium-dependent agonist bradykinin were quantified ex vivo with videomicroscopy. Vascular endothelial nitric oxide synthase (eNOS) and NAD(P)H-oxidase (Nox1, 2 and 4 isoforms) expression were measured with quantitative PCR. Glial fibrillary acidic protein (GFAP)-labeled astrocytes were quantified by unbiased stereological approaches in regions adjacent to the sites of WM-penetrating vessel collection. Post-mortem diffusion tensor imaging (DTI) was used to measure mean apparent diffusion coefficient (ADC) and fractional anisotropy (FA), quantitative indices of WM integrity. In contrast to pial surface arterioles, white matter-penetrating arterioles from donors diagnosed with high ADNC and mVBI exhibited a significantly reduced dilation in response to bradykinin when compared to the other groups. Expression of eNOS was reduced, whereas Nox1 expression was increased in WM arterioles in AD and mVBI cases. WM astrocyte density was increased in AD and mVBI, which correlated with a reduced vasodilation in WM arterioles. Moreover, in cases with low ADNC, bradykinin-induced WM arteriole dilation correlated with lower ADC and higher FA values. Comorbid ADNC and mVBI appear to synergistically interact to selectively impair bradykinin-induced vasodilation in WM-penetrating arterioles, which may be related to reduced nitric oxide- and excess reactive oxygen species-mediated vascular endothelial dysfunction. WM arteriole vasodilator dysfunction is associated with WM injury, as supported by reactive astrogliosis and MRI-defined disrupted WM microstructural integrity.
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Marshall RA, Luchkanych AMS, Morton JS, Boyes NG, Zhai A, Marciniuk DD, Mei Y, Allison EY, Shoemaker JK, Al-Khazraji BK, Allen MD, Tomczak CR, Olver TD. Cerebral haemodynamics during arrhythmia in health, ischaemic heart disease and heart failure with reduced ejection fraction, and in a preclinical swine model. J Physiol 2022; 600:2311-2325. [PMID: 35389526 DOI: 10.1113/jp283112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 04/04/2022] [Indexed: 12/29/2022] Open
Abstract
Ventricular arrhythmias are associated with neurological impairment and could represent a source of cerebral hypoperfusion. In the present study, data from healthy individuals (n = 11), patients with ischaemic heart disease (IHD; ejection fraction >40%; n = 9) and patients with heart failure with reduced ejection fraction (HFrEF; EF = 31 (5)%, n = 11), as well as data from swine surgeries, where spontaneous ventricular arrhythmias were observed during cerebrovascular examination (transcranial Doppler ultrasound in humans and laser Doppler in swine) were analysed retrospectively to investigate the effect of arrhythmia on cerebral microvascular haemodynamics. A subset of participants also completed the Montreal Cognitive Assessment (MoCA). Middle cerebral artery mean blood velocity (MCAVmean ) decreased during premature ventricular contraction (PVC) in all groups, and data from swine indicate PVCs reduced cerebral microvascular perfusion. Overall MCAVmean was decreased in the HFrEF vs. control group. Further, %∆MCAVmean /%∆mean arterial pressure during the PVC was greater in the HFrEF vs. control group and was correlated with decreased MoCA scores. Subanalysis of HFrEF data revealed that during bigeminy MCAVmean decreased owing to reductions during irregular beats only. During non-sustained ventricular tachycardia, MCAVmean decreased but recovered above baseline upon return to sinus rhythm. Also, haemodynamic perturbations during and following the PVC were greater in the brachial artery vs. the MCA. Therefore, ventricular arrhythmias decreased indices of cerebral perfusion irrespective of IHD or HFrEF. The relative magnitude of arrhythmia-induced haemodynamic perturbations appears to be population specific and arrhythmia type and organ dependent. The cumulative burden of arrhythmia-induced deficits may exacerbate existing cerebral hypoperfusion in HFrEF and contribute to neurological abnormalities in this population. KEY POINTS: Irregular heartbeats are often considered benign in isolation, but individuals who experience them frequently have a higher prevalence of cerebrovascular and/or cognitive associated disorders. How irregular heartbeats affect blood pressure and cerebral haemodynamics in healthy and cardiovascular disease patients, those with and without reduced ejection fraction, remains unknown. Here it was found that in the absence of symptoms associated with irregular heartbeats, such as dizziness or hypotension, single, multiple non-sustained and sustained irregular heartbeats influence cerebral haemodynamics in a population-specific, arrhythmia-type and organ-dependent manner. Relative deficits in the index of cerebral blood flow normalized to relative deficits in blood pressure were greatest in patients with heart failure with reduced ejection and inversely related with cognitive performance. Chronic arrhythmias may exacerbate existing cerebral hypoperfusion in heart failure with reduced ejection fraction, thereby providing a mechanistic link between otherwise benign irregular heartbeats and cognitive dysfunction, independent of embolism.
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Affiliation(s)
- Rory A Marshall
- Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Adam M S Luchkanych
- Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jude S Morton
- Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Natasha G Boyes
- College of Kinesiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Alexander Zhai
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Darcy D Marciniuk
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yixue Mei
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Elric Y Allison
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | | | - Baraa K Al-Khazraji
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Matti D Allen
- Department of Physical Medicine and Rehabilitation, School of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Corey R Tomczak
- College of Kinesiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - T Dylan Olver
- Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Allerkamp HH, Pole T, Boukham A, James JL, Clark AR. Predicting pregnancy specific uterine vascular reactivity: A data driven computational model of shear-dependent, myogenic, and mechanical radial artery features. Am J Physiol Heart Circ Physiol 2022; 323:H72-H88. [PMID: 35452318 DOI: 10.1152/ajpheart.00693.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The entire maternal circulation adapts to pregnancy, and this adaption is particularly extensive in the uterine circulation where the major vessels double in size to facilitate an approximately 15-fold increase in blood supply to this organ over the course of pregnancy. Several factors may play a role in both the remodelling and biomechanical function of the uterine vasculature including the paracrine microenvironment, passive properties of the vessel wall, and active components of vascular function (incorporating the myogenic response and response to shear stress induced by intravascular blood flow). However, the interplay between these factors, and how this plays out in an organ-specific manner to induce the extent of remodelling observed in the uterus is not well understood. Here we present an integrated assessment of the uterine radial arteries, likely rate-limiters to flow of oxygenated maternal blood to the placental surface, via computational modelling and pressure myography. We show that uterine radial arteries behave differently to other systemic vessels (higher compliance and shear mediated constriction) and that their properties change with the adaptation to pregnancy (higher myogenic tone, higher compliance, and ability to tolerate higher flow rates before constricting). Together, this provides a useful tool to improve our understanding of the role of uterine vascular adaptation in normal and abnormal pregnancies and highlights the need for vascular bed specific investigations of vascular function in health and disease.
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Affiliation(s)
- Hanna Helene Allerkamp
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Obstetrics and Gynecology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Teagan Pole
- Department of Obstetrics and Gynecology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Ali Boukham
- Mechanics and Engineering Institute (I2M), Environmental and Civil Engineering Department (GCE), University of Bordeaux, Talence, France
| | - Joanna L James
- Department of Obstetrics and Gynecology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Alys R Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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Panerai RB, Haunton VJ, Llwyd O, Minhas JS, Katsogridakis E, Salinet ASM, Maggio P, Robinson TG. Cerebral critical closing pressure and resistance-area product: the influence of dynamic cerebral autoregulation, age and sex. J Cereb Blood Flow Metab 2021; 41:2456-2469. [PMID: 33818187 PMCID: PMC8392773 DOI: 10.1177/0271678x211004131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 01/19/2021] [Accepted: 02/16/2021] [Indexed: 11/21/2022]
Abstract
Instantaneous arterial pressure-flow (or velocity) relationships indicate the existence of a cerebral critical closing pressure (CrCP), with the slope of the relationship expressed by the resistance-area product (RAP). In 194 healthy subjects (20-82 years, 90 female), cerebral blood flow velocity (CBFV, transcranial Doppler), arterial blood pressure (BP, Finapres) and end-tidal CO2 (EtCO2, capnography) were measured continuously for five minutes during spontaneous fluctuations of BP at rest. The dynamic cerebral autoregulation (CA) index (ARI) was extracted with transfer function analysis from the CBFV step response to the BP input and step responses were also obtained for the BP-CrCP and BP-RAP relationships. ARI was shown to decrease with age at a rate of -0.025 units/year in men (p = 0.022), but not in women (p = 0.40). The temporal patterns of the BP-CBFV, BP-CrCP and BP-RAP step responses were strongly influenced by the ARI (p < 0.0001), but not by sex. Age was also a significant determinant of the peak of the CBFV step response and the tail of the RAP response. Whilst the RAP step response pattern is consistent with a myogenic mechanism controlling dynamic CA, further work is needed to explore the potential association of the CrCP step response with the flow-mediated component of autoregulation.
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Affiliation(s)
- Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Victoria J Haunton
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Osian Llwyd
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Emmanuel Katsogridakis
- Department of Vascular Surgery, Wythenshawe Hospital, Manchester Foundation Trust, Manchester, UK
| | - Angela SM Salinet
- Neurology Department, Hospital das Clinicas, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Paola Maggio
- Neurology Department, ASST Bergamo EST (BG), Italy
| | - Thompson G Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
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Szenasi A, Amrein K, Czeiter E, Szarka N, Toth P, Koller A. Molecular Pathomechanisms of Impaired Flow-Induced Constriction of Cerebral Arteries Following Traumatic Brain Injury: A Potential Impact on Cerebral Autoregulation. Int J Mol Sci 2021; 22:6624. [PMID: 34205652 PMCID: PMC8234931 DOI: 10.3390/ijms22126624] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 01/21/2023] Open
Abstract
(1) Background: Traumatic brain injury (TBI) frequently occurs worldwide, resulting in high morbidity and mortality. Here, we hypothesized that TBI impairs an autoregulatory mechanism, namely the flow-induced constriction of isolated rat middle cerebral arteries (MCAs). (2) Methods: TBI was induced in anaesthetized rats by weight drop model, and then MCAs were isolated and transferred into a pressure-flow chamber. The internal diameter was measured by a video-microscopy. (3) Results: In MCAs from intact rats, increases in flow and pressure + flow elicited constrictions (-26 ± 1.9 µm and -52 ± 2.8 µm, p < 0.05), which were significantly reduced after TBI or in the presence of thromboxane-prostanoid (TP receptor) antagonist SQ 29,548. Flow-induced constrictions were significantly reduced by HET0016, inhibitor of cytochrome P450 4A (CYP450 4A). Arachidonic acid, (AA, 10-7 M), and CYP-450 4A metabolite 20-hydroxyeicosatetraenoic acid (20-HETE) elicited constrictions of intact MCA (-26 ± 2.3% and -31 ± 3.6%), which were significantly reduced after TBI (to 11 ± 1.3% and -16 ±2.5%). The TP receptor agonist U46619 (10-7 M) elicited substantial constrictions of MCA from intact rats (-21 ± 3.3%), which were also significantly reduced, after TBI (to -16 ± 2.4%). (4) Conclusions: Flow-induced constrictor response of MCA is impaired by traumatic brain injury, likely due to the reduced ability of cytochrome P450 4A to convert arachidonic acid to constrictor prostaglandins and the mitigated sensitivity of thromboxane-prostanoid receptors.
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Affiliation(s)
- Annamaria Szenasi
- Department of Translational Medicine, Faculty of Medicine, Semmelweis University, 1085 Budapest, Hungary;
- Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, 1085 Budapest, Hungary
| | - Krisztina Amrein
- Department of Neurosurgery and Szentágothai Research Center, University of Pecs, Medical School, 7623 Pecs, Hungary; (K.A.); (E.C.); (P.T.)
| | - Endre Czeiter
- Department of Neurosurgery and Szentágothai Research Center, University of Pecs, Medical School, 7623 Pecs, Hungary; (K.A.); (E.C.); (P.T.)
| | - Nikolett Szarka
- MTA-PTE Clinical Neuroscience MR Research Group, 7623 Pecs, Hungary;
| | - Peter Toth
- Department of Neurosurgery and Szentágothai Research Center, University of Pecs, Medical School, 7623 Pecs, Hungary; (K.A.); (E.C.); (P.T.)
- MTA-PTE Clinical Neuroscience MR Research Group, 7623 Pecs, Hungary;
| | - Akos Koller
- Department of Translational Medicine, Faculty of Medicine, Semmelweis University, 1085 Budapest, Hungary;
- Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, 1085 Budapest, Hungary
- Research Center for Sports Physiology, University of Physical Education, 1123 Budapest, Hungary
- Department of Physiology, New York Medical College, Valhalla, NY 10595, USA
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Kursun O, Karatas H, Bariskaner H, Ozturk S. Arachidonic Acid Metabolites in Neurologic Disorders. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 21:150-159. [PMID: 33982658 DOI: 10.2174/1871527320666210512013648] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND & OBJECTIVE Arachidonic acid (ARA) is essential for the fluidity, selective permeability, and flexibility of the cell membrane. It is an important factor for the function of all cells, particularly in the nervous system, immune system, and vascular endothelium. ARA, after docosahexaenoic acid, is the second most common polyunsaturated fatty acid in the phospholipids of the nerve cell membrane. ARA metabolites have many kinds of physiologic roles. The major action of ARA metabolites is the promotion of the acute inflammatory response, mediated by the production of pro-inflammatory mediators such as PGE2 and PGI2, followed by the formation of lipid mediators, which have pro-resolving effects. Another important action of ARA derivatives, especially COX, is the regulation of vascular reactivity through PGs and TXA2. There is significant involvement of ARA metabolites in neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and neuropsychiatric disorders. ARA derivatives also make an important contribution to acute stroke, global ischemia, subarachnoid hemorrhage, and anticoagulation- related hemorrhagic transformation. CONCLUSION In this review, we discuss experimental and human study results of neurologic disorders related to ARA and its metabolites in line with treatment options.
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Affiliation(s)
- Oguzhan Kursun
- Ankara City Hospital, Neurology Clinic, Neurointensive Care Unit, Neurology, Turkey
| | - Hulya Karatas
- Hacettepe University, Institute of Neurological Sciences and Psychiatry Neurology, Turkey
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10
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Jukic I, Mihaljevic Z, Matic A, Mihalj M, Kozina N, Selthofer-Relatic K, Mihaljevic D, Koller A, Tartaro Bujak I, Drenjancevic I. Angiotensin II type 1 receptor is involved in flow-induced vasomotor responses of isolated middle cerebral arteries: role of oxidative stress. Am J Physiol Heart Circ Physiol 2021; 320:H1609-H1624. [PMID: 33666506 DOI: 10.1152/ajpheart.00620.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 02/10/2021] [Indexed: 11/22/2022]
Abstract
This study aimed to determine the mechanosensing role of angiotensin II type 1 receptor (AT1R) in flow-induced dilation (FID) and oxidative stress production in middle cerebral arteries (MCA) of Sprague-Dawley rats. Eleven-week old, healthy male Sprague-Dawley rats on a standard diet were given the AT1R blocker losartan (1 mg/mL) in drinking water (losartan group) or tap water (control group) ad libitum for 7 days. Blockade of AT1R attenuated FID and acetylcholine-induced dilation was compared with control group. Nitric oxide (NO) synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME) and cyclooxygenase inhibitor indomethacin (Indo) significantly reduced FID in control group. The attenuated FID in losartan group was further reduced by Indo only at Δ100 mmHg, whereas l-NAME had no effect. In losartan group, Tempol (a superoxide scavenger) restored dilatation, whereas Tempol + l-NAME together significantly reduced FID compared with restored dilatation with Tempol alone. Direct fluorescence measurements of NO and reactive oxygen species (ROS) production in MCA, in no-flow conditions revealed significantly reduced vascular NO levels with AT1R blockade compared with control group, whereas in flow condition increased the NO and ROS production in losartan group and had no effect in the control group. In losartan group, Tempol decreased ROS production in both no-flow and flow conditions. AT1R blockade elicited increased serum concentrations of ANG II, 8-iso-PGF2α, and TBARS, and decreased antioxidant enzyme activity (SOD and CAT). These results suggest that in small isolated cerebral arteries: 1) AT1 receptor maintains dilations in physiological conditions; 2) AT1R blockade leads to increased vascular and systemic oxidative stress, which underlies impaired FID.NEW & NOTEWORTHY The AT1R blockade impaired the endothelium-dependent, both flow- and acetylcholine-induced dilations of MCA by decreasing vascular NO production and increasing the level of vascular and systemic oxidative stress, whereas it mildly influenced the vascular wall inflammatory phenotype, but had no effect on the systemic inflammatory response. Our data provide functional and molecular evidence for an important role of AT1 receptor activation in physiological conditions, suggesting that AT1 receptors have multiple biological functions.
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Affiliation(s)
- Ivana Jukic
- Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Zrinka Mihaljevic
- Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Anita Matic
- Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Martina Mihalj
- Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Department of Dermatology and Venereology, University Hospital Centre Osijek, Osijek, Croatia
| | - Natasa Kozina
- Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Kristina Selthofer-Relatic
- Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Department of Heart and Vascular Diseases, University Hospital Centre Osijek, Osijek, Croatia
- Department of Internal Medicine, Faculty of Medicine, University of Josip Juraj Strossmayer Osijek, Osijek, Croatia
| | - Dubravka Mihaljevic
- Department of Internal Medicine, Faculty of Medicine, University of Josip Juraj Strossmayer Osijek, Osijek, Croatia
- Department of Nephrology, University Hospital Centre Osijek, Osijek, Croatia
| | - Akos Koller
- Department of Neurosurgery and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
- Department of Morphology and Physiology, Semmelweis University, Budapest, Hungary
- Sport-Physiology Research Centre, University of Physical Education, Budapest, Hungary
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Ivana Tartaro Bujak
- Radiation Chemistry and Dosimetry Laboratory, Division of Materials Chemistry, Ruder Boskovic Institute, Zagreb, Croatia
| | - Ines Drenjancevic
- Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
- Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
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11
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Seeger DR, Golovko SA, Grove BD, Golovko MY. Cyclooxygenase inhibition attenuates brain angiogenesis and independently decreases mouse survival under hypoxia. J Neurochem 2021; 158:246-261. [PMID: 33389746 PMCID: PMC8249483 DOI: 10.1111/jnc.15291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/15/2020] [Accepted: 12/22/2020] [Indexed: 12/19/2022]
Abstract
Although cyclooxygenase (COX) role in cancer angiogenesis has been studied, little is known about its role in brain angioplasticity. In the present study, we chronically infused mice with ketorolac, a non‐specific COX inhibitor that does not cross the blood–brain barrier (BBB), under normoxia or 50% isobaric hypoxia (10% O2 by volume). Ketorolac increased mortality rate under hypoxia in a dose‐dependent manner. Using in vivo multiphoton microscopy, we demonstrated that chronic COX inhibition completely attenuated brain angiogenic response to hypoxia. Alterations in a number of angiogenic factors that were reported to be COX‐dependent in other models were assayed at 24‐hr and 10‐day hypoxia. Intriguingly, hypoxia‐inducible factor 1 was unaffected under COX inhibition, and vascular endothelial growth factor receptor type 2 (VEGFR2) and C‐X‐C chemokine receptor type 4 (CXCR4) were significantly but slightly decreased. However, a number of mitogen‐activated protein kinases (MAPKs) were significantly reduced upon COX inhibition. We conclude that additional, angiogenic factor‐independent mechanism might contribute to COX role in brain angioplasticity, probably including mitogenic COX effect on endothelium. Our data indicate that COX activity is critical for systemic adaptation to chronic hypoxia, and BBB COX is essential for hypoxia‐induced brain angioplasticity. These data also indicate a potential risk for using COX inhibitors under hypoxia conditions in clinics. Further studies are required to elucidate a complete mechanism for brain long‐term angiogenesis regulation through COX activity.
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Affiliation(s)
- Drew R Seeger
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, USA
| | - Svetlana A Golovko
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, USA
| | - Bryon D Grove
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, USA
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12
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Pénzes M, Túrós D, Máthé D, Szigeti K, Hegedűs N, Rauscher AÁ, Tóth P, Ivic I, Padmanabhan P, Pál G, Dobolyi Á, Gyimesi M, Málnási-Csizmadia A. Direct myosin-2 inhibition enhances cerebral perfusion resulting in functional improvement after ischemic stroke. Theranostics 2020; 10:5341-5356. [PMID: 32373216 PMCID: PMC7196296 DOI: 10.7150/thno.42077] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/03/2020] [Indexed: 12/29/2022] Open
Abstract
Acute ischemic stroke treatment faces an unresolved obstacle as capillary reperfusion remains insufficient after thrombolysis and thrombectomy causing neuronal damage and poor prognosis. Hypoxia-induced capillary constriction is mediated by actomyosin contraction in precapillary smooth muscle cells (SMCs) therefore smooth muscle myosin-2 could be an ideal target with potentially high impact on reperfusion of capillaries. Methods: The myosin-2 inhibitor para-aminoblebbistatin (AmBleb) was tested on isolated human and rat arterioles to assess the effect of AmBleb on vasodilatation. Transient middle cerebral artery occlusion (MCAO) was performed on 38 male Wistar rats followed by local administration of AmBleb into the ischemic brain area. Development of brain edema and changes in cerebrovascular blood flow were assessed using MRI and SPECT. We also tested the neurological deficit scores and locomotor asymmetry of the animals for 3 weeks after the MCAO operation. Results: Our results demonstrate that AmBleb could achieve full relaxation of isolated cerebral arterioles. In living animals AmBleb recovered cerebral blood flow in 32 out of the 65 affected functional brain areas in MCAO operated rats, whereas only 8 out of the 67 affected areas were recovered in the control animals. Animals treated with AmBleb also showed significantly improved general and focal deficit scores in neurological functional tests and showed significantly ameliorated locomotor asymmetry. Conclusion: Direct inhibition of smooth muscle myosin by AmBleb in pre-capillary SMCs significantly contribute to the improvement of cerebral blood reperfusion and brain functions suggesting that smooth muscle myosin inhibition may have promising potential in stroke therapies as a follow-up treatment of physical or chemical removal of the occluding thrombus.
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13
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Czigler A, Toth L, Szarka N, Szilágyi K, Kellermayer Z, Harci A, Vecsernyes M, Ungvari Z, Szolics A, Koller A, Buki A, Toth P. Prostaglandin E 2, a postulated mediator of neurovascular coupling, at low concentrations dilates whereas at higher concentrations constricts human cerebral parenchymal arterioles. Prostaglandins Other Lipid Mediat 2019; 146:106389. [PMID: 31689497 DOI: 10.1016/j.prostaglandins.2019.106389] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/18/2019] [Accepted: 10/28/2019] [Indexed: 02/04/2023]
Abstract
There is considerable controversy regarding the vasoactive action of prostaglandin E2 (PGE2). On the one hand, indirect evidence implicates that astrocytic release of PGE2 contributes to neurovascular coupling responses mediating functional hyperemia in the brain. On the other hand, overproduction of PGE2 was also reported to contribute to cerebral vasospasm associated with subarachnoid hemorrhage. The present study was conducted to resolve this controversy by determining the direct vasoactive effects of PGE2 in resistance-sized human cerebral parenchymal arterioles. To achieve this goal PGE2-induced isotonic vasomotor responses were assessed in parenchymal arterioles isolated from fronto-temporo-parietal cortical tissues surgically removed from patients and expression of PGE2 receptors were examined. In functionally intact parenchymal arterioles lower concentrations of PGE2 (from 10-8 to 10-6 mol/l) caused significant, endothelium-independent vasorelaxation, which was inhibited by the EP4 receptor blocker BGC201531. In contrast, higher concentrations of PGE2 evoked significant EP1-dependent vasoconstriction, which could not be reversed by the EP4 receptor agonist CAY10598. We also confirmed previous observations that PGE2 primarily evokes constriction in intracerebral arterioles isolated from R. norvegicus. Importantly, vascular mRNA and protein expression of vasodilator EP4 receptors was significantly higher than that of vasoconstrictor EP1 receptors in human cerebral arterioles. PGE2 at low concentrations dilates whereas at higher concentrations constricts human cerebral parenchymal arterioles. This bimodal vasomotor response is consistent with both the proposed vasodilator role of PGE2 during functional hyperemia and its putative role in cerebral vasospasm associated with subarachnoid hemorrhage in human patients.
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Affiliation(s)
- Andras Czigler
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary; Institute for Translational Medicine, University of Pecs, Medical School, Pecs, Hungary
| | - Luca Toth
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary; Institute for Translational Medicine, University of Pecs, Medical School, Pecs, Hungary
| | - Nikolett Szarka
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary; Institute for Translational Medicine, University of Pecs, Medical School, Pecs, Hungary
| | - Krisztina Szilágyi
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary; Institute for Translational Medicine, University of Pecs, Medical School, Pecs, Hungary
| | - Zoltan Kellermayer
- Department of Immunology and Biotechnology, University of Pecs, Medical School, Pecs, Hungary
| | - Alexandra Harci
- Department of Medical Biology and Central Electron Microscope Laboratory, University of Pecs, Medical School, Pecs, Hungary
| | - Monika Vecsernyes
- Department of Medical Biology and Central Electron Microscope Laboratory, University of Pecs, Medical School, Pecs, Hungary
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
| | - Alex Szolics
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary
| | - Akos Koller
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary; Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary; Department of Physiology, New York Medical College, Valhalla, NY USA
| | - Andras Buki
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary
| | - Peter Toth
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Medical School, Pecs, Hungary; Institute for Translational Medicine, University of Pecs, Medical School, Pecs, Hungary; Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA; MTA-PTE Clinical Neuroscience MR Research Group, Pecs, Hungary.
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14
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Lagier D, Tonon D, Garrigue P, Guillet B, Giacomino L, Martin JC, Alessi MC, Bruder N, Velly LJ. Thromboxane-prostaglandin receptor antagonist, terutroban, prevents neurovascular events after subarachnoid haemorrhage: a nanoSPECT study in rats. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2019; 23:42. [PMID: 30744667 PMCID: PMC6371436 DOI: 10.1186/s13054-019-2338-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 01/31/2019] [Indexed: 12/12/2022]
Abstract
Background Several lipid metabolites in cerebrospinal fluid are correlated with poor outcomes in aneurysmal subarachnoid haemorrhage. Most of these metabolites bind to ubiquitous thromboxane–prostaglandin (TP) receptors, causing vasoconstriction and inflammation. Here, we evaluated terutroban (TBN), a specific TP receptor antagonist, for the prevention of post-haemorrhage blood-brain barrier disruption, neuronal apoptosis and delayed cerebral hypoperfusion. Methods The rat double subarachnoid haemorrhage model was produced by twice injecting (days 1 and 2) autologous blood into the cisterna magna. Seventy-eight male Sprague-Dawley rats were assigned to experimental groups. Rats exposed to subarachnoid haemorrhage were allocated to no treatment (SAH group) or TBN treatment by gastric gavage during the first 5 days after haemorrhage (SAH+TBN group). Control rats received artificial cerebrospinal fluid injections (CSF group). Sham-operated rats with or without TBN administration were also studied. Body weight and Garcia neurological scores were assessed on day 2 and day 5. We used nanoscale single-photon emission computed tomography (nanoSPECT) to measure brain uptake of three radiolabelled agents: 99mTechnetium-diethylenetriaminepentacetate (99mTc-DTPA), which indicated blood-brain barrier permeability on day 3, 99mTechnetium-annexin V-128 (99mTc-Anx-V128), which indicated apoptosis on day 4, and 99mTechnetium-hexamethylpropyleneamineoxime (99mTc-HMPAO), which indicated cerebral perfusion on day 5. Basilar artery narrowing was verified histologically, and cerebral TP receptor agonists were quantified. Results 99mTc-DTPA uptake unveiled blood-brain barrier disruption in the SAH group. TBN mitigated this disruption in the brainstem area. 99mTc-Anx-V128 uptake was increased in the SAH group and TBN diminished this effect in the cerebellum. 99mTc-HMPAO uptake revealed a global decreased perfusion on day 5 in the SAH group that was significantly counteracted by TBN. TBN also mitigated basilar artery vasoconstriction, neurological deficits (on day 2), body weight loss (on day 5) and cerebral production of vasoconstrictors such as Thromboxane B2 and Prostaglandin F2α. Conclusions Based on in vivo nanoscale imaging, we demonstrated that TBN protected against blood-brain barrier disruption, exerted an anti-apoptotic effect and improved cerebral perfusion. Thus, TP receptor antagonists showed promising results in treating post-haemorrhage neurovascular events.
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Affiliation(s)
- David Lagier
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Timone, Marseille, France. .,C2VN Inserm 1263, Inra 1260, Aix Marseille University, Marseille, France.
| | - David Tonon
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Timone, Marseille, France.,C2VN Inserm 1263, Inra 1260, Aix Marseille University, Marseille, France
| | - Philippe Garrigue
- CERIMED (European Center for Research in Medical Imaging), Aix Marseille University, Marseille, France
| | - Benjamin Guillet
- CERIMED (European Center for Research in Medical Imaging), Aix Marseille University, Marseille, France
| | - Laura Giacomino
- Department of Anaesthesiology and Critical Care Medicine, INT (Institut de Neurosciences de la Timone), University Hospital Timone, Aix Marseille University, Marseille, France
| | | | | | - Nicolas Bruder
- Department of Anaesthesiology and Critical Care Medicine, University Hospital Timone, Marseille, France
| | - Lionel J Velly
- Department of Anaesthesiology and Critical Care Medicine, INT (Institut de Neurosciences de la Timone), University Hospital Timone, Aix Marseille University, Marseille, France
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Toth P, Tarantini S, Rutkai I, Ungvari Z. Assessment of endothelial function in leptomeningeal arterioles derived from patients with Alzheimer's disease and vascular cognitive impairment. Am J Physiol Heart Circ Physiol 2018; 315:H790-H793. [PMID: 29932773 DOI: 10.1152/ajpheart.00367.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Peter Toth
- Department of Neurosurgery, Medical School, University of Pecs , Pecs , Hungary.,Institute for Translational Medicine, Medical School, University of Pecs , Pecs , Hungary.,MTA-PTE Clinical Neuroscience MR Research Group of the Hungarian Academy of Sciences , Pecs , Hungary.,Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma
| | - Stefano Tarantini
- Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma
| | - Ibolya Rutkai
- Department of Pharmacology, Tulane University, School of Medicine, New Orleans, Louisana
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma
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Mouat MA, Coleman JLJ, Smith NJ. GPCRs in context: sexual dimorphism in the cardiovascular system. Br J Pharmacol 2018; 175:4047-4059. [PMID: 29451687 DOI: 10.1111/bph.14160] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/31/2018] [Accepted: 02/09/2018] [Indexed: 12/31/2022] Open
Abstract
Cardiovascular disease (CVD) remains the largest cause of mortality worldwide, and there is a clear gender gap in disease occurrence, with men being predisposed to earlier onset of CVD, including atherosclerosis and hypertension, relative to women. Oestrogen may be a driving factor for female-specific cardioprotection, though androgens and sex chromosomes are also likely to contribute to sexual dimorphism in the cardiovascular system (CVS). Many GPCR-mediated processes are involved in cardiovascular homeostasis, and some exhibit clear sex divergence. Here, we focus on the G protein-coupled oestrogen receptor, endothelin receptors ETA and ETB and the eicosanoid G protein-coupled receptors (GPCRs), discussing the evidence and potential mechanisms leading to gender dimorphic responses in the vasculature. The use of animal models and pharmacological tools has been essential to understanding the role of these receptors in the CVS and will be key to further delineating their sex-specific effects. Ultimately, this may illuminate wider sex differences in cardiovascular pathology and physiology. LINKED ARTICLES This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc.
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Affiliation(s)
- Margaret A Mouat
- Molecular Pharmacology Laboratory, Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, NSW, Australia
| | - James L J Coleman
- Molecular Pharmacology Laboratory, Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, NSW, Australia
| | - Nicola J Smith
- Molecular Pharmacology Laboratory, Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, NSW, Australia
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Avolio A, Kim MO, Adji A, Gangoda S, Avadhanam B, Tan I, Butlin M. Cerebral Haemodynamics: Effects of Systemic Arterial Pulsatile Function and Hypertension. Curr Hypertens Rep 2018; 20:20. [PMID: 29556793 DOI: 10.1007/s11906-018-0822-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Concepts of pulsatile arterial haemodynamics, including relationships between oscillatory blood pressure and flow in systemic arteries, arterial stiffness and wave propagation phenomena have provided basic understanding of underlying haemodynamic mechanisms associated with elevated arterial blood pressure as a major factor of cardiovascular risk, particularly the deleterious effects of isolated systolic hypertension in the elderly. This topical review assesses the effects of pulsatility of blood pressure and flow in the systemic arteries on the brain. The review builds on the emerging notion of the "pulsating brain", taking into account the high throughput of blood flow in the cerebral circulation in the presence of mechanisms involved in ensuring efficient and regulated cerebral perfusion. RECENT FINDINGS Recent studies have provided evidence of the relevance of pulsatility and hypertension in the following areas: (i) pressure and flow pulsatility and regulation of cerebral blood flow, (ii) cerebral and systemic haemodynamics, hypertension and brain pathologies (cognitive impairment, dementia, Alzheimer's disease), (iii) stroke and cerebral small vessel disease, (iv) cerebral haemodynamics and noninvasive estimation of cerebral vascular impedance, (v) cerebral and systemic pulsatile haemodynamics and intracranial pressure, (iv) response of brain endothelial cells to cyclic mechanical stretch and increase in amyloid burden. Studies to date, producing increasing epidemiological, clinical and experimental evidence, suggest a potentially significant role of systemic haemodynamic pulsatility on structure and function of the brain.
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Affiliation(s)
- Alberto Avolio
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
| | - Mi Ok Kim
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Audrey Adji
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia.,St. Vincent's Clinic, Victor Chang Cardiac Research Institute, University of New South Wales, Sydney, Australia
| | - Sumudu Gangoda
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Bhargava Avadhanam
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Isabella Tan
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Mark Butlin
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
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Szarka N, Pabbidi MR, Amrein K, Czeiter E, Berta G, Pohoczky K, Helyes Z, Ungvari Z, Koller A, Buki A, Toth P. Traumatic Brain Injury Impairs Myogenic Constriction of Cerebral Arteries: Role of Mitochondria-Derived H 2O 2 and TRPV4-Dependent Activation of BK ca Channels. J Neurotrauma 2018; 35:930-939. [PMID: 29179622 DOI: 10.1089/neu.2017.5056] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) impairs autoregulation of cerebral blood flow, which contributes to the development of secondary brain injury, increasing mortality of patients. Impairment of pressure-induced myogenic constriction of cerebral arteries plays a critical role in autoregulatory dysfunction; however, the underlying cellular and molecular mechanisms are not well understood. To determine the role of mitochondria-derived H2O2 and large-conductance calcium-activated potassium channels (BKCa) in myogenic autoregulatory dysfunction, middle cerebral arteries (MCAs) were isolated from rats with severe weight drop-impact acceleration brain injury. We found that 24 h post-TBI MCAs exhibited impaired myogenic constriction, which was restored by treatment with a mitochondria-targeted antioxidant (mitoTEMPO), by scavenging of H2O2 (polyethylene glycol [PEG]-catalase) and by blocking both BKCa channels (paxilline) and transient receptor potential cation channel subfamily V member 4 (TRPV4) channels (HC 067047). Further, exogenous administration of H2O2 elicited significant dilation of MCAs, which was inhibited by blocking either BKCa or TRPV4 channels. Vasodilation induced by the TRPV4 agonist GSK1016790A was inhibited by paxilline. In cultured vascular smooth muscle cells H2O2 activated BKCa currents, which were inhibited by blockade of TRPV4 channels. Collectively, our results suggest that after TBI, excessive mitochondria-derived H2O2 activates BKCa channels via a TRPV4-dependent pathway in the vascular smooth muscle cells, which impairs pressure-induced constriction of cerebral arteries. Future studies should elucidate the therapeutic potential of pharmacological targeting of this pathway in TBI, to restore autoregulatory function in order to prevent secondary brain damage and decrease mortality.
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Affiliation(s)
- Nikolett Szarka
- Cerebrovascular Laboratory, Department of Neurosurgery, Medical School University of Pecs, Pecs. Hungary.,Neurotrauma Research Group, Janos Szentagothai Research Center, Medical School University of Pecs, Pecs. Hungary.,Department of Translational Medicine, Medical School University of Pecs, Pecs. Hungary
| | - Mallikarjuna R Pabbidi
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Krisztina Amrein
- Cerebrovascular Laboratory, Department of Neurosurgery, Medical School University of Pecs, Pecs. Hungary.,Neurotrauma Research Group, Janos Szentagothai Research Center, Medical School University of Pecs, Pecs. Hungary
| | - Endre Czeiter
- Cerebrovascular Laboratory, Department of Neurosurgery, Medical School University of Pecs, Pecs. Hungary.,Neurotrauma Research Group, Janos Szentagothai Research Center, Medical School University of Pecs, Pecs. Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pecs, Hungary
| | - Gergely Berta
- Department of Medical Biology, Medical School University of Pecs, Pecs. Hungary
| | - Krisztina Pohoczky
- Department of Pharmacology and Pharmacotherapy, Medical School University of Pecs, Pecs. Hungary.,MTA-PTE NAP B Chronic Pain Research Group, Pecs, Hungary
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School University of Pecs, Pecs. Hungary.,MTA-PTE NAP B Chronic Pain Research Group, Pecs, Hungary
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Akos Koller
- Cerebrovascular Laboratory, Department of Neurosurgery, Medical School University of Pecs, Pecs. Hungary.,Institute of Natural Sciences, University of Physical Education, Budapest, Hungary.,Department of Physiology, New York Medical College, Valhalla, New York
| | - Andras Buki
- Cerebrovascular Laboratory, Department of Neurosurgery, Medical School University of Pecs, Pecs. Hungary.,Neurotrauma Research Group, Janos Szentagothai Research Center, Medical School University of Pecs, Pecs. Hungary
| | - Peter Toth
- Cerebrovascular Laboratory, Department of Neurosurgery, Medical School University of Pecs, Pecs. Hungary.,Neurotrauma Research Group, Janos Szentagothai Research Center, Medical School University of Pecs, Pecs. Hungary.,Department of Translational Medicine, Medical School University of Pecs, Pecs. Hungary.,MTA-PTE Clinical Neuroscience MR Research Group, Pecs, Hungary.,Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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19
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Chen G, Carter RE, Cleary JD, Reid TS, Ranum LP, Swanson MS, Ebner TJ. Altered levels of the splicing factor muscleblind modifies cerebral cortical function in mouse models of myotonic dystrophy. Neurobiol Dis 2018; 112:35-48. [PMID: 29331264 PMCID: PMC5859959 DOI: 10.1016/j.nbd.2018.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/20/2017] [Accepted: 01/08/2018] [Indexed: 01/18/2023] Open
Abstract
Myotonic dystrophy (DM) is a progressive, multisystem disorder affecting skeletal muscle, heart, and central nervous system. In both DM1 and DM2, microsatellite expansions of CUG and CCUG RNA repeats, respectively, accumulate and disrupt functions of alternative splicing factors, including muscleblind (MBNL) proteins. Grey matter loss and white matter changes, including the corpus callosum, likely underlie cognitive and executive function deficits in DM patients. However, little is known how cerebral cortical circuitry changes in DM. Here, flavoprotein optical imaging was used to assess local and contralateral responses to intracortical motor cortex stimulation in DM-related mouse models. In control mice, brief train stimulation generated ipsilateral and contralateral homotopic fluorescence increases, the latter mediated by the corpus callosum. Single pulse stimulation produced an excitatory response with an inhibitory-like surround response mediated by GABAA receptors. In a mouse model of DM2 (Mbnl2 KO), we observed prolonged and increased responsiveness to train stimulation and loss of the inhibition from single pulse stimulation. Conversely, mice overexpressing human MBNL1 (MBNL1-OE) exhibited decreased contralateral response to train stimulation and reduction of inhibitory-like surround to single pulse stimulation. Therefore, altering levels of two key DM-associated splicing factors modifies functions of local cortical circuits and contralateral responses mediated through the corpus callosum.
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Affiliation(s)
- Gang Chen
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Russell E Carter
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - John D Cleary
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Tammy S Reid
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Laura P Ranum
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Maurice S Swanson
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Timothy J Ebner
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA.
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20
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Bagi Z, Brandner DD, Le P, McNeal DW, Gong X, Dou H, Fulton DJ, Beller A, Ngyuen T, Larson EB, Montine TJ, Keene CD, Back SA. Vasodilator dysfunction and oligodendrocyte dysmaturation in aging white matter. Ann Neurol 2018; 83:142-152. [PMID: 29283444 PMCID: PMC5876126 DOI: 10.1002/ana.25129] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/24/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Microvascular brain injury (mVBI) is a common pathological correlate of vascular contributions to cognitive impairment and dementia (VCID) that leads to white matter (WM) injury (WMI). VCID appears to arise from chronic recurrent white matter ischemia that triggers oxidative stress and an increase in total oligodendrocyte lineage cells. We hypothesized that mVBI involves vasodilator dysfunction of white matter penetrating arterioles and aberrant oligodendrocyte progenitor cell (OPC) responses to WMI. METHODS We analyzed cases of mVBI with low Alzheimer's disease neuropathological change in prefrontal cortex WM from rapid autopsies in a population-based cohort where VCID frequently occurs. Arteriolar vasodilator function was quantified by videomicroscopy. OPC maturation was quantified using lineage specific markers. RESULTS Acetylcholine-mediated arteriolar dilation in mVBI was significantly reduced in WM penetrators relative to pial arterioles. Astrogliosis-defined WMI was positively associated with increased OPCs and was negatively associated with decreased mature oligodendrocytes. INTERPRETATION Selectively impaired vasodilator function of WM penetrating arterioles in mVBI occurs in association with aberrant differentiation of OPCs in WMI, which supports that myelination disturbances in VCID are related to disrupted maturation of myelinating oligodendrocytes. Ann Neurol 2018;83:142-152.
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Affiliation(s)
- Zsolt Bagi
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912
| | - Dieter D. Brandner
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239
| | - Phuong Le
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239
| | - David W. McNeal
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239
| | - Xi Gong
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239
| | - Huijuan Dou
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912
| | - David J Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912
| | - Allison Beller
- Department of Pathology, University of Washington, Seattle, Washington
| | - Thuan Ngyuen
- Department of Preventive Medicine, Oregon Health & Science University, Portland, Oregon 97239
| | | | - Thomas J. Montine
- Department of Pathology, University of Washington, Seattle, Washington
| | - C. Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington
| | - Stephen A. Back
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239
- Department of Neurology, Oregon Health & Science University, Portland, Oregon 97239
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Abstract
Cytochrome P450 eicosanoids play important roles in brain function and disease through their complementary actions on cell-cell communications within the neurovascular unit (NVU) and mechanisms of brain injury. Epoxy- and hydroxyeicosanoids, respectively formed by cytochrome P450 epoxygenases and ω-hydroxylases, play opposing roles in cerebrovascular function and in pathological processes underlying neural injury, including ischemia, neuroinflammation and oxidative injury. P450 eicosanoids also contribute to cerebrovascular disease risk factors, including hypertension and diabetes. We summarize studies investigating the roles P450 eicosanoids in cerebrovascular physiology and disease to highlight the existing balance between these important lipid signaling molecules, as well as their roles in maintaining neurovascular homeostasis and in acute and chronic neurovascular and neurodegenerative disorders.
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Affiliation(s)
- Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR 97239, United States; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, United States
| | - Xuehong Liu
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, United States
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR 97239, United States; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, United States.
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22
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Szarka N, Amrein K, Horvath P, Ivic I, Czeiter E, Buki A, Koller A, Toth P. Hypertension-Induced Enhanced Myogenic Constriction of Cerebral Arteries Is Preserved after Traumatic Brain Injury. J Neurotrauma 2017; 34:2315-2319. [PMID: 28249552 DOI: 10.1089/neu.2016.4962] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) was shown to impair pressure-induced myogenic response of cerebral arteries, which is associated with vascular and neural dysfunction and increased mortality of TBI patients. Hypertension was shown to enhance myogenic tone of cerebral arteries via increased vascular production of 20-hydroxyeicosatrienoic acid (HETE). This adaptive mechanism protects brain tissue from pressure/volume overload; however, it can also lead to increased susceptibility to cerebral ischemia. Although both effects may potentiate the detrimental vascular consequences of TBI, it is not known how hypertension modulates the effect of TBI on myogenic responses of cerebral vessels. We hypothesized that in hypertensive rats, the enhanced myogenic cerebrovascular response is preserved after TBI. Therefore, we investigated the myogenic responses of isolated middle cerebral arteries (MCA) of normotensive and spontaneously hypertensive rats (SHR) after severe impact acceleration diffuse brain injury. TBI diminished myogenic constriction of MCAs isolated from normotensive rats, whereas the 20-HETE-mediated enhanced myogenic response of MCAs isolated from SHRs was not affected by TBI. These results suggest that the optimal cerebral perfusion pressure values and vascular signaling pathways can be different and, therefore, should be targeted differently in normotensive and hypertensive patients following TBI.
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Affiliation(s)
- Nikolett Szarka
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary .,2 Department of Translational Medicine, University of Pecs , Pecs, Hungary
| | - Krisztina Amrein
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary .,3 MTA-PTE Clinical Neuroscience MR Research Group , Pecs, Hungary
| | - Peter Horvath
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary
| | - Ivan Ivic
- 2 Department of Translational Medicine, University of Pecs , Pecs, Hungary
| | - Endre Czeiter
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary .,3 MTA-PTE Clinical Neuroscience MR Research Group , Pecs, Hungary
| | - Andras Buki
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary .,3 MTA-PTE Clinical Neuroscience MR Research Group , Pecs, Hungary
| | - Akos Koller
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary .,4 Institute of Natural Sciences, University of Physical Education , Budapest, Hungary .,5 Department of Physiology, New York Medical College , Valhalla, New York
| | - Peter Toth
- 1 Department of Neurosurgery and Szentagothai Research Center, University of Pecs , Pecs, Hungary .,2 Department of Translational Medicine, University of Pecs , Pecs, Hungary .,3 MTA-PTE Clinical Neuroscience MR Research Group , Pecs, Hungary .,6 Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma
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23
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Hegeduš I, Milić J, Ćosić A, Buljan K, Drenjančević I. Cerebrovascular reactivity in acute hyperoxia in patients with acute ischaemic stroke. Brain Inj 2017; 31:560-566. [DOI: 10.1080/02699052.2017.1280853] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ivana Hegeduš
- Department of Neurology, Osijek University Hospital, Osijek, Croatia
| | - Jakov Milić
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Anita Ćosić
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Krunoslav Buljan
- Department of Neurology, Osijek University Hospital, Osijek, Croatia
| | - Ines Drenjančević
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
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24
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Cseplo P, Vamos Z, Torok O, Ivic I, Toth A, Buki A, Koller A. Hemolyzed Blood Elicits a Calcium Antagonist and High CO 2 Reversible Constriction via Elevation of [Ca 2+] i in Isolated Cerebral Arteries. J Neurotrauma 2017; 34:529-534. [PMID: 27018759 DOI: 10.1089/neu.2015.4365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During acute subarachnoid hemorrhage, blood is hemolyzed, which is followed by a significant cerebrovascular spasm resulting in a serious clinical condition. Interestingly, however, the direct vasomotor effect of perivascular hemolyzed blood (HB) has not yet been characterized, preventing the assessment of contribution of vasoconstrictor mechanisms deriving from brain tissue and/or blood and development of possible treatments. We hypothesized that perivascular HB reduces the diameter of the cerebral arteries (i.e., basilar artery [BA]; middle cerebral artery [MCA]) by elevating vascular tissue [Ca2+]i level. Vasomotor responses were measured by videomicroscopy and intracellular Ca2+ by the Fura2-AM ratiometric method. Adding HB to the vessel chamber reduced the diameter significantly (BA: from 264 ± 7 to 164 ± 11 μm; MCA: from 185 ± 15 to 155 ± 14 μm), which was reversed to control level by wash-out of HB. Potassium chloride (KCl), HB, serum, hemolyzed red blood cell (RBC), plasma, and platelet suspension (PLTs) elicited significant constrictions of isolated basilar arteries. There was a significant increase in K+ concentration in hemolyzed HB (7.02 ± 0.22 mmol/L) compared to Krebs' solution (6.20 ± 0.01 mmol/L). Before HB, acetylcholine (ACh), sodium-nitroprussid (SNP), nifedipin, and CO2 elicited substantial dilations in cerebral arteries. In contrast, in the presence of HB dilations to ACh, SNP decreased, but not to nifedipine and CO2. After washout of HB, nitric oxide-mediated dilations remained significantly reduced compared to control. HB significantly increased the ratiometric Ca signal, which returned to control level after washout. In conclusion, perivascular hemolyzed blood elicits significant-nifedipine and high CO2 reversible-constrictions of isolated BAs and MCAs, primarily by increasing intracellular Ca2+, findings that can contribute to the refinement of local treatment of subarachnoid hemorrhage.
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Affiliation(s)
- Peter Cseplo
- 1 Institute of Translational Medicine, University of Pecs , Medical School, Pecs, Hungary .,2 Department of Central Anesthesiology and Intensive Therapy, Petz Aladar County Teaching Hospital , Gyor, Hungary .,6 Szentagothai Research Centre, University of Pecs , Pecs, Hungary
| | - Zoltan Vamos
- 3 Department of Anaesthesiology and Intensive Therapy, University of Pecs , Medical School, Pecs, Hungary
| | - Orsolya Torok
- 1 Institute of Translational Medicine, University of Pecs , Medical School, Pecs, Hungary
| | - Ivan Ivic
- 1 Institute of Translational Medicine, University of Pecs , Medical School, Pecs, Hungary
| | - Attila Toth
- 4 Institute of Cardiology, Division of Clinical Physiology, Faculty of Medicine, University of Debrecen , Debrecen, Hungary
| | - Andras Buki
- 5 Department of Neurosurgery, University of Pecs , Medical School, Pecs, Hungary .,6 Szentagothai Research Centre, University of Pecs , Pecs, Hungary .,7 MTA-PTE Clinical Neuroscience MR Research Group , Pecs, Hungary
| | - Akos Koller
- 1 Institute of Translational Medicine, University of Pecs , Medical School, Pecs, Hungary .,5 Department of Neurosurgery, University of Pecs , Medical School, Pecs, Hungary .,6 Szentagothai Research Centre, University of Pecs , Pecs, Hungary .,8 Institute of Natural Sciences, University of Physical Education , Budapest, Hungary .,9 Department of Physiology, New York Medical College , Valhalla, New York
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25
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Toth P, Tarantini S, Csiszar A, Ungvari Z. Functional vascular contributions to cognitive impairment and dementia: mechanisms and consequences of cerebral autoregulatory dysfunction, endothelial impairment, and neurovascular uncoupling in aging. Am J Physiol Heart Circ Physiol 2017; 312:H1-H20. [PMID: 27793855 PMCID: PMC5283909 DOI: 10.1152/ajpheart.00581.2016] [Citation(s) in RCA: 310] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/10/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022]
Abstract
Increasing evidence from epidemiological, clinical and experimental studies indicate that age-related cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including Alzheimer's disease. Understanding and targeting the age-related pathophysiological mechanisms that underlie vascular contributions to cognitive impairment and dementia (VCID) are expected to have a major role in preserving brain health in older individuals. Maintenance of cerebral perfusion, protecting the microcirculation from high pressure-induced damage and moment-to-moment adjustment of regional oxygen and nutrient supply to changes in demand are prerequisites for the prevention of cerebral ischemia and neuronal dysfunction. This overview discusses age-related alterations in three main regulatory paradigms involved in the regulation of cerebral blood flow (CBF): cerebral autoregulation/myogenic constriction, endothelium-dependent vasomotor function, and neurovascular coupling responses responsible for functional hyperemia. The pathophysiological consequences of cerebral microvascular dysregulation in aging are explored, including blood-brain barrier disruption, neuroinflammation, exacerbation of neurodegeneration, development of cerebral microhemorrhages, microvascular rarefaction, and ischemic neuronal dysfunction and damage. Due to the widespread attention that VCID has captured in recent years, the evidence for the causal role of cerebral microvascular dysregulation in cognitive decline is critically examined.
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Affiliation(s)
- Peter Toth
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Pecs, Hungary; and
| | - Stefano Tarantini
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Anna Csiszar
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma;
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
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26
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Toth P, Szarka N, Farkas E, Ezer E, Czeiter E, Amrein K, Ungvari Z, Hartings JA, Buki A, Koller A. Traumatic brain injury-induced autoregulatory dysfunction and spreading depression-related neurovascular uncoupling: Pathomechanisms, perspectives, and therapeutic implications. Am J Physiol Heart Circ Physiol 2016; 311:H1118-H1131. [PMID: 27614225 PMCID: PMC5504422 DOI: 10.1152/ajpheart.00267.2016] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 08/19/2016] [Indexed: 01/17/2023]
Abstract
Traumatic brain injury (TBI) is a major health problem worldwide. In addition to its high mortality (35-40%), survivors are left with cognitive, behavioral, and communicative disabilities. While little can be done to reverse initial primary brain damage caused by trauma, the secondary injury of cerebral tissue due to cerebromicrovascular alterations and dysregulation of cerebral blood flow (CBF) is potentially preventable. This review focuses on functional, cellular, and molecular changes of autoregulatory function of CBF (with special focus on cerebrovascular myogenic response) that occur in cerebral circulation after TBI and explores the links between autoregulatory dysfunction, impaired myogenic response, microvascular impairment, and the development of secondary brain damage. We further provide a synthesized translational view of molecular and cellular mechanisms involved in cortical spreading depolarization-related neurovascular dysfunction, which could be targeted for the prevention or amelioration of TBI-induced secondary brain damage.
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Affiliation(s)
- Peter Toth
- Department of Neurosurgery, University of Pecs, Pecs, Hungary;
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Nikolett Szarka
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
- Department of Translational Medicine, University of Pecs, Pecs, Hungary
| | - Eszter Farkas
- Faculty of Medicine and Faculty of Science and Informatics, Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Erzsebet Ezer
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
| | - Endre Czeiter
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
- MTA-PTE Clinical Neuroscience MR Research Group, Pecs, Hungary
| | - Krisztina Amrein
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
- MTA-PTE Clinical Neuroscience MR Research Group, Pecs, Hungary
| | - Zoltan Ungvari
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Jed A Hartings
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Andras Buki
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
- MTA-PTE Clinical Neuroscience MR Research Group, Pecs, Hungary
| | - Akos Koller
- Department of Neurosurgery, University of Pecs, Pecs, Hungary
- Janos Szentagothai Research Centre, University of Pecs, Pecs, Hungary
- Institute of Natural Sciences, University of Physical Education, Budapest, Hungary; and
- Department of Physiology, New York Medical College, Valhalla, New York
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27
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Cseplo P, Vamos Z, Ivic I, Torok O, Toth A, Koller A. The Beta-1-Receptor Blocker Nebivolol Elicits Dilation of Cerebral Arteries by Reducing Smooth Muscle [Ca2+]i. PLoS One 2016; 11:e0164010. [PMID: 27716772 PMCID: PMC5055296 DOI: 10.1371/journal.pone.0164010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 09/19/2016] [Indexed: 01/22/2023] Open
Abstract
Rationale Nebivolol is known to have beta-1 blocker activity, but it was also suggested that it elicits relaxation of the peripheral arteries in part via release of nitric oxide (NO). However, the effect of nebivolol on the vasomotor tone of cerebral arteries is still unclear. Objective To assess the effects of nebivolol on the diameter of isolated rat basilar arteries (BA) in control, in the presence of inhibitors of vasomotor signaling pathways of know action and hemolysed blood. Methods and Results Vasomotor responses were measured by videomicroscopy and the intracellular Ca2+ by the Fura-2 AM ratiometric method. Under control conditions, nebivolol elicited a substantial dilation of the BA (from 216±22 to 394±20 μm; p<0.05) in a concentration-dependent manner (10−7 to 10−4 M). The dilatation was significantly reduced by endothelium denudation or by L-NAME (inhibitor of NO synthase) or by SQ22536 (adenylyl cyclase blocker). Dilatation of BA was also affected by beta-2 receptor blockade with butoxamine, but not by the guanylate cyclase blocker ODQ. Interestingly, beta-1 blockade by atenolol inhibited nebivolol-induced dilation. Also, the BKCa channel blocker iberiotoxin and KCa channel inhibitor TEA significantly reduced nebivolol-induced dilation. Nebivolol significantly reduced smooth muscle Ca2+ level, which correlated with the increases in diameters and moreover it reversed the hemolysed blood-induced constriction of BA. Conclusions Nebivolol seems to have an important dilator effect in cerebral arteries, which is mediated via several vasomotor mechanisms, converging on the reduction of smooth muscle Ca2+ levels. As such, nebivolol may be effective to improve cerebral circulation in various diseased conditions, such as hemorrhage.
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Affiliation(s)
- Peter Cseplo
- Institute for Translational Medicine and Szentagothai Research Centre, University of Pecs, Medical School, Pecs, Hungary.,Department of Central Anesthesiology and Intensive Therapy, Petz Aladar County Teaching Hospital, Gyor, Hungary
| | - Zoltan Vamos
- Institute for Translational Medicine and Szentagothai Research Centre, University of Pecs, Medical School, Pecs, Hungary.,Department of Anaesthesiology and Intensive Therapy, University of Pecs, Medical School, Pecs, Hungary
| | - Ivan Ivic
- Institute for Translational Medicine and Szentagothai Research Centre, University of Pecs, Medical School, Pecs, Hungary.,Department of Anatomy, University of Pecs, Medical School, Pecs, Hungary
| | - Orsolya Torok
- Institute for Translational Medicine and Szentagothai Research Centre, University of Pecs, Medical School, Pecs, Hungary
| | - Attila Toth
- Institute of Cardiology, Division of Clinical Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Akos Koller
- Institute for Translational Medicine and Szentagothai Research Centre, University of Pecs, Medical School, Pecs, Hungary.,Department of Neurosurgery, University of Pecs, Medical School, Pecs, Hungary.,Department of Physiology, New York Medical College, Valhalla, New York, United States of America.,Institute of Natural Sciences, University of Physical Education, Budapest, Hungary
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Wiest EF, Walsh-Wilcox MT, Rothe M, Schunck WH, Walker MK. Dietary Omega-3 Polyunsaturated Fatty Acids Prevent Vascular Dysfunction and Attenuate Cytochrome P4501A1 Expression by 2,3,7,8-Tetrachlorodibenzo-P-Dioxin. Toxicol Sci 2016; 154:43-54. [PMID: 27492226 DOI: 10.1093/toxsci/kfw145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Omega-3 polyunsaturated fatty acids (n-3 PUFAs) found in fish protect against cardiovascular morbidity and mortality; however, many individuals avoid fish consumption due to concerns about pollutants. We tested the hypothesis that n-3 PUFAs would prevent vascular dysfunction induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). C57Bl/6 male mice were fed a chow or n-3 PUFA diet for 10 weeks and were exposed to vehicle or 300 ng/kg/d TCDD during the final 2 weeks on each diet. Aortic vasoconstriction mediated by arachidonic acid (AA) ± SKF525 (P450 inhibitor) or SQ29548 (thromboxane/prostanoid [TP] receptor antagonist) was assessed. RBC fatty acids and expression of n-3 and n-6 PUFA metabolites were analyzed. Cytochrome P4501A1 (CYP1A1), CYP1B1, and aryl hydrocarbon receptor (AHR) expression was measured. TCDD significantly increased AA-mediated vasoconstriction on a chow diet by increasing the contribution of P450s and TP receptor to the constriction response. In contrast, the n-3 PUFA diet prevented the TCDD-induced increase in AA vasoconstriction and normalized the contribution of P450s and TP receptor. Although TCDD increased the levels of AA vasoconstrictors on the chow diet, this increase was prevent by the n-3 PUFA diet. Additionally, the n-3 PUFA diet significantly increased the levels of n-3 PUFA-derived vasodilators and TCDD increased these levels further. Interestingly, the n-3 PUFA diet significantly attenuated CYP1A1 induction by TCDD without a significant effect on AHR expression. These data suggest that n-3 PUFAs can prevent TCDD-induced vascular dysfunction by decreasing vasoconstrictors, increasing vasodilators, and attenuating CYP1A1 induction, which has been shown previously to contribute to TCDD-induced vascular dysfunction.
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Affiliation(s)
- Elani F Wiest
- *Department of Pharmaceutical Sciences, University of New Mexico, New Mexico, 87131
| | - Mary T Walsh-Wilcox
- *Department of Pharmaceutical Sciences, University of New Mexico, New Mexico, 87131
| | | | | | - Mary K Walker
- *Department of Pharmaceutical Sciences, University of New Mexico, New Mexico, 87131
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Cosic A, Jukic I, Stupin A, Mihalj M, Mihaljevic Z, Novak S, Vukovic R, Drenjancevic I. Attenuated flow-induced dilatation of middle cerebral arteries is related to increased vascular oxidative stress in rats on a short-term high salt diet. J Physiol 2016; 594:4917-31. [PMID: 27061200 DOI: 10.1113/jp272297] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/05/2016] [Indexed: 01/20/2023] Open
Abstract
KEY POINTS Recent studies have shown that high salt (HS) intake leads to endothelial dysfunction and impaired vascular reactivity in different vascular beds in both animal and human models, due to increased oxidative stress. The objective of this study was to assess vascular response to flow-induced dilatation (FID) and to elucidate the role of vascular oxidative stress/antioxidative capacity in middle cerebral arteries (MCAs) of HS-fed rats in vitro. The novelty of this study is in demonstrating impaired flow-induced dilatation of MCAs and down-regulation of vascular antioxidant genes with HS intake, leading to increased levels of oxidative stress in blood vessels and peripheral lymph organs, which together contribute to impaired FID. In addition, results show increased oxidative stress in leukocytes of peripheral lymph organs, suggesting the occurrence of inflammatory processes due to HS intake. Recirculation of leukocytes might additionally increase vascular oxidative stress in vivo. ABSTRACT The aim of this study was to determine flow-induced dilatation (FID) and the role of oxidative stress/antioxidative capacity in isolated, pressurized middle cerebral arteries (MCAs) of high salt (HS)-fed rats. Healthy male Sprague-Dawley rats (11 weeks old) were fed low salt (0.4% NaCl; LS group) or high salt (4% NaCl; HS group) diets for 1 week. Reactivity of MCAs in response to stepwise increases in pressure gradient (Δ10-Δ100 mmHg) was determined in the absence or presence of the superoxide dismutase (SOD) mimetic TEMPOL and/or the nitric oxide synthases (NOS) inhibitor N(ω) -nitro-l-arginine methyl ester (l-NAME). mRNA levels of antioxidative enzymes, NAPDH-oxidase components, inducible (iNOS) and endothelial nitric oxide synthases (eNOS) were determined by quantitative real-time PCR. Blood pressure (BP), antioxidant enzymes activity, oxidative stress in peripheral leukocytes, lipid peroxidation products and the antioxidant capacity of plasma were measured for both groups. FID was reduced in the HS group compared to the LS group. The presence of TEMPOL restored dilatation in the HS group, with no effect in the LS group. Expression of glutathione peroxidase 4 (GPx4) and iNOS in the HS group was significantly decreased; oxidative stress was significantly higher in the HS group compared to the LS group. HS intake significantly induced basal reactive oxygen species production in the leukocytes of mesenteric lymph nodes and splenocytes, and intracellular production after stimulation in peripheral lymph nodes. Antioxidant enzyme activity and BP were not affected by HS diet. Low GPx4 expression, increased superoxide production in leukocytes, and decreased iNOS expression are likely to underlie increased oxidative stress and reduced nitric oxide bioavailability, leading to impairment of FID in the HS group without changes in BP values.
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Affiliation(s)
- Anita Cosic
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Ivana Jukic
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Ana Stupin
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Martina Mihalj
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Zrinka Mihaljevic
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Sanja Novak
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Rosemary Vukovic
- Department of Biology, J. J. Strossmayer University of Osijek, Croatia
| | - Ines Drenjancevic
- Department of Physiology and Immunology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
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West JD, Voss BM, Pavliv L, de Caestecker M, Hemnes AR, Carrier EJ. Antagonism of the thromboxane-prostanoid receptor is cardioprotective against right ventricular pressure overload. Pulm Circ 2016; 6:211-23. [PMID: 27252848 DOI: 10.1086/686140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH) and is a significant cause of morbidity and mortality in other forms of pulmonary hypertension. There are no approved therapies directed at preserving RV function. F-series and E-series isoprostanes are increased in heart failure and PAH, correlate to the severity of disease, and can signal through the thromboxane-prostanoid (TP) receptor, with effects from vasoconstriction to fibrosis. The goal of these studies was to determine whether blockade of the TP receptor with the antagonist CPI211 was beneficial therapeutically in PAH-induced RV dysfunction. Mice with RV dysfunction due to pressure overload by pulmonary artery banding (PAB) were given vehicle or CPI211. Two weeks after PAB, CPI211-treated mice were protected from fibrosis with pressure overload. Gene expression arrays and immunoblotting, quantitative histology and morphometry, and flow cytometric analysis were used to determine the mechanism of CPI211 protection. TP receptor inhibition caused a near normalization of fibrotic area, prevented cellular hypertrophy while allowing increased RV mass, increased expression of antifibrotic thrombospondin-4, and blocked induction of the profibrotic transforming growth factor β (TGF-β) pathway. A thromboxane synthase inhibitor or low-dose aspirin failed to replicate these results, which suggests that a ligand other than thromboxane mediates fibrosis through the TP receptor after pressure overload. This study suggests that TP receptor antagonism may improve RV adaptation in situations of pressure overload by decreasing fibrosis and TGF-β signaling.
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Affiliation(s)
- James D West
- Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Bryan M Voss
- Cumberland Pharmaceuticals, Nashville, Tennessee, USA
| | - Leo Pavliv
- Cumberland Pharmaceuticals, Nashville, Tennessee, USA
| | - Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Anna R Hemnes
- Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Erica J Carrier
- Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Filosa JA, Morrison HW, Iddings JA, Du W, Kim KJ. Beyond neurovascular coupling, role of astrocytes in the regulation of vascular tone. Neuroscience 2016; 323:96-109. [PMID: 25843438 PMCID: PMC4592693 DOI: 10.1016/j.neuroscience.2015.03.064] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/24/2015] [Accepted: 03/27/2015] [Indexed: 12/22/2022]
Abstract
The brain possesses two intricate mechanisms that fulfill its continuous metabolic needs: cerebral autoregulation, which ensures constant cerebral blood flow over a wide range of arterial pressures and functional hyperemia, which ensures rapid delivery of oxygen and glucose to active neurons. Over the past decade, a number of important studies have identified astrocytes as key intermediaries in neurovascular coupling (NVC), the mechanism by which active neurons signal blood vessels to change their diameter. Activity-dependent increases in astrocytic Ca(2+) activity are thought to contribute to the release of vasoactive substances that facilitate arteriole vasodilation. A number of vasoactive signals have been identified and their role on vessel caliber assessed both in vitro and in vivo. In this review, we discuss mechanisms implicating astrocytes in NVC-mediated vascular responses, limitations encountered as a result of the challenges in maintaining all the constituents of the neurovascular unit intact and deliberate current controversial findings disputing a main role for astrocytes in NVC. Finally, we briefly discuss the potential role of pericytes and microglia in NVC-mediated processes.
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Affiliation(s)
- J A Filosa
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States.
| | - H W Morrison
- University of Arizona, 1305 N. Martin Avenue, P.O. Box 210203, Tucson, AZ 85721, United States
| | - J A Iddings
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
| | - W Du
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
| | - K J Kim
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
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Lakhkar A, Dhagia V, Joshi SR, Gotlinger K, Patel D, Sun D, Wolin MS, Schwartzman ML, Gupte SA. 20-HETE-induced mitochondrial superoxide production and inflammatory phenotype in vascular smooth muscle is prevented by glucose-6-phosphate dehydrogenase inhibition. Am J Physiol Heart Circ Physiol 2016; 310:H1107-17. [PMID: 26921441 DOI: 10.1152/ajpheart.00961.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/23/2016] [Indexed: 02/07/2023]
Abstract
20-Hydroxyeicosatetraeonic acid (20-HETE) produced by cytochrome P-450 monooxygenases in NADPH-dependent manner is proinflammatory, and it contributes to the pathogenesis of systemic and pulmonary hypertension. In this study, we tested the hypothesis that inhibition of glucose-6-phosphate dehydrogenase (G6PD), a major source of NADPH in the cell, prevents 20-HETE synthesis and 20-HETE-induced proinflammatory signaling that promotes secretory phenotype of vascular smooth muscle cells. Lipidomic analysis indicated that G6PD inhibition and knockdown decreased 20-HETE levels in pulmonary arteries as well as 20-HETE-induced 1) mitochondrial superoxide production, 2) activation of mitogen-activated protein kinase 1 and 3, 3) phosphorylation of ETS domain-containing protein Elk-1 that activate transcription of tumor necrosis factor-α gene (Tnfa), and 4) expression of tumor necrosis factor-α (TNF-α). Moreover, inhibition of G6PD increased protein kinase G1α activity, which, at least partially, mitigated superoxide production and Elk-1 and TNF-α expression. Additionally, we report here for the first time that 20-HETE repressed miR-143, which suppresses Elk-1 expression, and miR-133a, which is known to suppress synthetic/secretory phenotype of vascular smooth muscle cells. In summary, our findings indicate that 20-HETE elicited mitochondrial superoxide production and promoted secretory phenotype of vascular smooth muscle cells by activating MAPK1-Elk-1, all of which are blocked by inhibition of G6PD.
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Affiliation(s)
- Anand Lakhkar
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Vidhi Dhagia
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Sachindra Raj Joshi
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Katherine Gotlinger
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Dhara Patel
- Department of Physiology, New York Medical College School of Medicine, Valhalla, New York; and
| | - Dong Sun
- Department of Physiology, New York Medical College School of Medicine, Valhalla, New York; and
| | - Michael S Wolin
- Department of Physiology, New York Medical College School of Medicine, Valhalla, New York; and Translational Centre for Pulmonary Hypertension, New York Medical College School of Medicine, Valhalla, New York
| | - Michal L Schwartzman
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Sachin A Gupte
- Department of Pharmacology, New York Medical College School of Medicine, Valhalla, New York; Translational Centre for Pulmonary Hypertension, New York Medical College School of Medicine, Valhalla, New York
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Benyó Z, Ruisanchez É, Leszl-Ishiguro M, Sándor P, Pacher P. Endocannabinoids in cerebrovascular regulation. Am J Physiol Heart Circ Physiol 2016; 310:H785-801. [PMID: 26825517 DOI: 10.1152/ajpheart.00571.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 01/25/2016] [Indexed: 02/08/2023]
Abstract
The cerebral blood flow is tightly regulated by myogenic, endothelial, metabolic, and neural mechanisms under physiological conditions, and a large body of recent evidence indicates that inflammatory pathways have a major influence on the cerebral blood perfusion in certain central nervous system disorders, like hemorrhagic and ischemic stroke, traumatic brain injury, and vascular dementia. All major cell types involved in cerebrovascular control pathways (i.e., smooth muscle, endothelium, neurons, astrocytes, pericytes, microglia, and leukocytes) are capable of synthesizing endocannabinoids and/or express some or several of their target proteins [i.e., the cannabinoid 1 and 2 (CB1 and CB2) receptors and the transient receptor potential vanilloid type 1 ion channel]. Therefore, the endocannabinoid system may importantly modulate the regulation of cerebral circulation under physiological and pathophysiological conditions in a very complex manner. Experimental data accumulated since the late 1990s indicate that the direct effect of cannabinoids on cerebral vessels is vasodilation mediated, at least in part, by CB1 receptors. Cannabinoid-induced cerebrovascular relaxation involves both a direct inhibition of smooth muscle contractility and a release of vasodilator mediator(s) from the endothelium. However, under stress conditions (e.g., in conscious restrained animals or during hypoxia and hypercapnia), cannabinoid receptor activation was shown to induce a reduction of the cerebral blood flow, probably via inhibition of the electrical and/or metabolic activity of neurons. Finally, in certain cerebrovascular pathologies (e.g., subarachnoid hemorrhage, as well as traumatic and ischemic brain injury), activation of CB2 (and probably yet unidentified non-CB1/non-CB2) receptors appear to improve the blood perfusion of the brain via attenuating vascular inflammation.
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Affiliation(s)
- Zoltán Benyó
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Éva Ruisanchez
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Miriam Leszl-Ishiguro
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Péter Sándor
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary; and
| | - Pál Pacher
- Laboratory of Cardiovascular Physiology and Tissue Injury, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
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Toth P, Tarantini S, Davila A, Valcarcel-Ares MN, Tucsek Z, Varamini B, Ballabh P, Sonntag WE, Baur JA, Csiszar A, Ungvari Z. Purinergic glio-endothelial coupling during neuronal activity: role of P2Y1 receptors and eNOS in functional hyperemia in the mouse somatosensory cortex. Am J Physiol Heart Circ Physiol 2015; 309:H1837-45. [PMID: 26453330 DOI: 10.1152/ajpheart.00463.2015] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/25/2015] [Indexed: 12/22/2022]
Abstract
Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of cognitive impairment associated with aging and pathological conditions associated with accelerated cerebromicrovascular aging (e.g., hypertension, obesity). Although previous studies demonstrate that endothelial dysfunction plays a critical role in neurovascular uncoupling in these conditions, the role of endothelial NO mediation in neurovascular coupling responses is not well understood. To establish the link between endothelial function and functional hyperemia, neurovascular coupling responses were studied in mutant mice overexpressing or deficient in endothelial NO synthase (eNOS), and the role of P2Y1 receptors in purinergic glioendothelial coupling was assessed. We found that genetic depletion of eNOS (eNOS(-/-)) and pharmacological inhibition of NO synthesis significantly decreased the CBF responses in the somatosensory cortex evoked by whisker stimulation and by administration of ATP. Overexpression of eNOS enhanced NO mediation of functional hyperemia. In control mice, the selective and potent P2Y1 receptor antagonist MRS2179 attenuated both whisker stimulation-induced and ATP-mediated CBF responses, whereas, in eNOS(-/-) mice, the inhibitory effects of MRS2179 were blunted. Collectively, our findings provide additional evidence for purinergic glio-endothelial coupling during neuronal activity, highlighting the role of ATP-mediated activation of eNOS via P2Y1 receptors in functional hyperemia.
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Affiliation(s)
- Peter Toth
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Department of Neurosurgery, University of Pecs, Pecs, Hungary; Szentagothai Research Center, Medical School, University of Pecs, Pecs, Hungary
| | - Stefano Tarantini
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Antonio Davila
- Institute for Diabetes, Obesity, and Metabolism and Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - M Noa Valcarcel-Ares
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Zsuzsanna Tucsek
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Szentagothai Research Center, Medical School, University of Pecs, Pecs, Hungary
| | - Behzad Varamini
- Biological Sciences Department, Biola University, La Mirada, California
| | - Praveen Ballabh
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York; Department of Pediatrics, Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, New York
| | - William E Sonntag
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Joseph A Baur
- Institute for Diabetes, Obesity, and Metabolism and Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anna Csiszar
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Szentagothai Research Center, Medical School, University of Pecs, Pecs, Hungary; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Szentagothai Research Center, Medical School, University of Pecs, Pecs, Hungary; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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Abstract
Basal and activity-dependent cerebral blood flow changes are coordinated by the action of critical processes, including cerebral autoregulation, endothelial-mediated signaling, and neurovascular coupling. The goal of our study was to determine whether astrocytes contribute to the regulation of parenchymal arteriole (PA) tone in response to hemodynamic stimuli (pressure/flow). Cortical PA vascular responses and astrocytic Ca(2+) dynamics were measured using an in vitro rat/mouse brain slice model of perfused/pressurized PAs; studies were supplemented with in vivo astrocytic Ca(2+) imaging. In vitro, astrocytes responded to PA flow/pressure increases with an increase in intracellular Ca(2+). Astrocytic Ca(2+) responses were corroborated in vivo, where acute systemic phenylephrine-induced increases in blood pressure evoked a significant increase in astrocytic Ca(2+). In vitro, flow/pressure-evoked vasoconstriction was blunted when the astrocytic syncytium was loaded with BAPTA (chelating intracellular Ca(2+)) and enhanced when high Ca(2+) or ATP were introduced to the astrocytic syncytium. Bath application of either the TRPV4 channel blocker HC067047 or purinergic receptor antagonist suramin blunted flow/pressure-evoked vasoconstriction, whereas K(+) and 20-HETE signaling blockade showed no effect. Importantly, we found TRPV4 channel expression to be restricted to astrocytes and not the endothelium of PA. We present evidence for a novel role of astrocytes in PA flow/pressure-evoked vasoconstriction. Our data suggest that astrocytic TRPV4 channels are key molecular sensors of hemodynamic stimuli and that a purinergic, glial-derived signal contributes to flow/pressure-induced adjustments in PA tone. Together our results support bidirectional signaling within the neurovascular unit and astrocytes as key modulators of PA tone.
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Toth P, Csiszar A, Sosnowska D, Tucsek Z, Cseplo P, Springo Z, Tarantini S, Sonntag WE, Ungvari Z, Koller A. Treatment with the cytochrome P450 ω-hydroxylase inhibitor HET0016 attenuates cerebrovascular inflammation, oxidative stress and improves vasomotor function in spontaneously hypertensive rats. Br J Pharmacol 2015. [PMID: 23194285 DOI: 10.1111/bph.12079] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Hypertension increases cerebrovascular oxidative stress and inflammation and impairs vasomotor function. These pathological alterations lead to dysregulation of cerebral blood flow and exacerbate atherogenesis, increasing the morbidity of ischaemic cerebrovascular diseases and promoting vascular cognitive impairment. We aimed to test the hypothesis that increased production of the arachidonic acid metabolite 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE) contributes to hypertension-induced cerebrovascular alterations. EXPERIMENTAL APPROACH We treated male spontaneously hypertensive rats (SHR) with HET0016 (N-hydroxy-N'-(4-butyl-2-methylphenyl)-formamidine), an inhibitor of 20-HETE synthesis. In middle cerebral arteries (MCAs) of SHRs, we focused on vasomotor responses and end points that are highly relevant for cellular reactive oxygen species (ROS) production, inflammatory cytokine expression and NF-κB activation. KEY RESULTS SHRs treated with HET0016 remained hypertensive (SHR + HET0016: 149 ± 8 mmHg, Wistar-Kyoto rat: 115 ± 4 mmHg; P < 0.05.), although their systolic blood pressure was decreased compared to untreated SHRs (191 ± 6 mmHg). In MCAs of SHRs, flow-induced constriction was increased, whereas ACh- and ATP-induced dilations were impaired. This functional impairment was reversed by treatment with HET0016. Treatment with HET0016 also significantly decreased oxidative stress in MCAs of SHRs (as shown by dihydroethidium staining and analysis of vascular 5-nitrotyrosine, 4-hydroxynonenal and carbonyl content) and inhibited cerebrovascular inflammation (shown by the reduced mRNA expression of TNFα, IL-1β and IL-6). Treatment of SHRs with HET0016 also attenuated vascular NF-κB activation. In vitro treatment with 20-HETE significantly increased vascular production of ROS and promoted NF-κB activation in cultured cerebromicrovascular endothelial cells. CONCLUSIONS AND IMPLICATIONS Taken together, treatment with HET0016 confers anti-oxidative and anti-inflammatory effects in the cerebral arteries of SHRs by disrupting 20-HETE-mediated autocrine/paracrine signalling pathways in the vascular wall. It is likely that HET0016-induced decreases in blood pressure also potentiate the cerebrovascular protective effects of the drug.
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Affiliation(s)
- Peter Toth
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma, Oklahoma City, OK 73104, USA
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Matsumoto T, Goulopoulou S, Taguchi K, Tostes RC, Kobayashi T. Constrictor prostanoids and uridine adenosine tetraphosphate: vascular mediators and therapeutic targets in hypertension and diabetes. Br J Pharmacol 2015; 172:3980-4001. [PMID: 26031319 DOI: 10.1111/bph.13205] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/16/2015] [Accepted: 05/19/2015] [Indexed: 12/22/2022] Open
Abstract
Vascular dysfunction plays a pivotal role in the development of systemic complications associated with arterial hypertension and diabetes. The endothelium, or more specifically, various factors derived from endothelial cells tightly regulate vascular function, including vascular tone. In physiological conditions, there is a balance between endothelium-derived factors, that is, relaxing factors (endothelium-derived relaxing factors; EDRFs) and contracting factors (endothelium-derived contracting factors; EDCFs), which mediate vascular homeostasis. However, in disease states, such as diabetes and arterial hypertension, there is an imbalance between EDRF and EDCF, with a reduction of EDRF signalling and an increase of EDCF signalling. Among EDCFs, COX-derived vasoconstrictor prostanoids play an important role in the development of vascular dysfunction associated with hypertension and diabetes. Moreover, uridine adenosine tetraphosphate (Up4 A), identified as an EDCF in 2005, also modulates vascular function. However, the role of Up4 A in hypertension- and diabetes-associated vascular dysfunction is unclear. In the present review, we focused on experimental and clinical evidence that implicate these two EDCFs (vasoconstrictor prostanoids and Up4 A) in vascular dysfunction associated with hypertension and diabetes.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, Japan
| | - Styliani Goulopoulou
- Department of Integrative Physiology and Anatomy, Obstetrics and Gynecology, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, Japan
| | - Rita C Tostes
- Department of Pharmacology, Ribeirao Preto Medical School University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, Japan
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Hill-Eubanks DC, Gonzales AL, Sonkusare SK, Nelson MT. Vascular TRP channels: performing under pressure and going with the flow. Physiology (Bethesda) 2015; 29:343-60. [PMID: 25180264 DOI: 10.1152/physiol.00009.2014] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endothelial cells and smooth muscle cells of resistance arteries mediate opposing responses to mechanical forces acting on the vasculature, promoting dilation in response to flow and constriction in response to pressure, respectively. In this review, we explore the role of TRP channels, particularly endothelial TRPV4 and smooth muscle TRPC6 and TRPM4 channels, in vascular mechanosensing circuits, placing their putative mechanosensitivity in context with other proposed upstream and downstream signaling pathways.
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Affiliation(s)
| | - Albert L Gonzales
- Department of Pharmacology, University of Vermont, Burlington, Vermont
| | | | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, Vermont
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Nemeth Z, Cziraki A, Szabados S, Horvath I, Koller A. Pericardial fluid of cardiac patients elicits arterial constriction: role of endothelin-1. Can J Physiol Pharmacol 2015; 93:779-85. [PMID: 26322806 DOI: 10.1139/cjpp-2015-0030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, several vasoactive molecules have been found in pericardial fluid (PF). Thus, we hypothesized that in coronary artery disease due to ischemia or ischemia-reperfusion, the level of vasoconstrictors, mainly endothelin-1 (ET-1), increases in PF, which can increase the vasomotor tone of arteries. Experiments were performed using an isometric myograph. Vasomotor effects of PF from patients undergoing coronary artery bypass graft (PFCABG, n = 14) or valve replacement (PFVR, n = 7) surgery were examined in isolated rat carotid arteries (N = 14; n = 26). Vasomotor responses to KCl (40 or 60 mmol/L) were also tested. The selective endothelin A receptor antagonist BQ123 (10(-6) mol/L) was used to elucidate the role of ET-1. Both the first and the second additions of KCl elicited increases in the isometric force of the isolated arteries (KCl1, 6.1 ± 0.2 mN; KCl2, 6.5 ± 0.9 mN). PFCABG and PFVR elicited substantial increases in the isometric force of arteries (PFCABG, 3.1 ± 0.7 mN; PFVR, 3.0 ± 0.9 mN; p > 0.05). The presence of the selective endothelin A receptor blocker significantly reduced arterial contractions to PFCABG (before BQ123, 2.6 ± 0.5 mN vs. after BQ123, 0.8 ± 0.1 mN; p < 0.05). This study is the first to demonstrate that PFs of patients elicit substantial arterial constrictions, which is mediated primarily by ET-1. Interfering with the vasoconstrictor action of PF could be a potential therapeutic target to improve coronary blood flow in cardiac patients.
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Affiliation(s)
- Zoltan Nemeth
- a University of Pecs, Medical School, Department of Pathophysiology and Gerontology and Szentagothai Research Centre, Pecs, Hungary
| | - Attila Cziraki
- b University of Pecs, Medical School, Heart Institute, Pecs, Hungary
| | - Sandor Szabados
- b University of Pecs, Medical School, Heart Institute, Pecs, Hungary
| | - Ivan Horvath
- b University of Pecs, Medical School, Heart Institute, Pecs, Hungary
| | - Akos Koller
- a University of Pecs, Medical School, Department of Pathophysiology and Gerontology and Szentagothai Research Centre, Pecs, Hungary.,c University of Physical Education, Institute of Natural Sciences, Budapest, Hungary.,d Department of Physiology, New York Medical College, Valhalla, NY 10595, USA
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Sofronova SI, Tarasova OS, Gaynullina D, Borzykh AA, Behnke BJ, Stabley JN, McCullough DJ, Maraj JJ, Hanna M, Muller-Delp JM, Vinogradova OL, Delp MD. Spaceflight on the Bion-M1 biosatellite alters cerebral artery vasomotor and mechanical properties in mice. J Appl Physiol (1985) 2015; 118:830-8. [PMID: 25593287 PMCID: PMC4385880 DOI: 10.1152/japplphysiol.00976.2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/13/2015] [Indexed: 01/03/2023] Open
Abstract
Conditions during spaceflight, such as the loss of the head-to-foot gravity vector, are thought to potentially alter cerebral blood flow and vascular resistance. The purpose of the present study was to determine the effects of long-term spaceflight on the functional, mechanical, and structural properties of cerebral arteries. Male C57BL/6N mice were flown 30 days in a Bion-M1 biosatellite. Basilar arteries isolated from spaceflight (SF) (n = 6), habitat control (HC) (n = 6), and vivarium control (VC) (n = 16) mice were used for in vitro functional and mechanical testing and histological structural analysis. The results demonstrate that vasoconstriction elicited through a voltage-gated Ca(2+) mechanism (30-80 mM KCl) and thromboxane A2 receptors (10(-8) - 3 × 10(-5) M U46619) are lower in cerebral arteries from SF mice. Inhibition of Rho-kinase activity (1 μM Y27632) abolished group differences in U46619-evoked contractions. Endothelium-dependent vasodilation elicited by acetylcholine (10 μM, 2 μM U46619 preconstriction) was virtually absent in cerebral arteries from SF mice. The pressure-diameter relation was lower in arteries from SF mice relative to that in HC mice, which was not related to differences in the extracellular matrix protein elastin or collagen content or the elastin/collagen ratio in the basilar arteries. Diameter, medial wall thickness, and medial cross-sectional area of unpressurized basilar arteries were not different among groups. These results suggest that the microgravity-induced attenuation of both vasoconstrictor and vasodilator properties may limit the range of vascular control of cerebral perfusion or impair the distribution of brain blood flow during periods of stress.
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Affiliation(s)
- Svetlana I Sofronova
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; Faculty of Biology, M.V. Lomonosov Moscow State University
| | - Olga S Tarasova
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; Faculty of Biology, M.V. Lomonosov Moscow State University
| | - Dina Gaynullina
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow; Faculty of Biology, M.V. Lomonosov Moscow State University; Department of Physiology, Russian National Research Medical University, Moscow, Russia
| | - Anna A Borzykh
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow
| | - Bradley J Behnke
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - John N Stabley
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Danielle J McCullough
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Joshua J Maraj
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Mina Hanna
- Department of Materials Science and Engineering, Stanford University, Stanford, California
| | - Judy M Muller-Delp
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida; and
| | | | - Michael D Delp
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida; Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
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Fan F, Geurts AM, Murphy SR, Pabbidi MR, Jacob HJ, Roman RJ. Impaired myogenic response and autoregulation of cerebral blood flow is rescued in CYP4A1 transgenic Dahl salt-sensitive rat. Am J Physiol Regul Integr Comp Physiol 2014; 308:R379-90. [PMID: 25540098 DOI: 10.1152/ajpregu.00256.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We have reported that a reduction in renal production of 20-HETE contributes to development of hypertension in Dahl salt-sensitive (SS) rats. The present study examined whether 20-HETE production is also reduced in the cerebral vasculature of SS rats and whether this impairs the myogenic response and autoregulation of cerebral blood flow (CBF). The production of 20-HETE, the myogenic response of middle cerebral arteries (MCA), and autoregulation of CBF were compared in SS, SS-5(BN) rats and a newly generated CYP4A1 transgenic rat. 20-HETE production was 6-fold higher in cerebral arteries of CYP4A1 and SS-5(BN) than in SS rats. The diameter of the MCA decreased to 70 ± 3% to 65 ± 6% in CYP4A1 and SS-5(BN) rats when pressure was increased from 40 to 140 mmHg. In contrast, the myogenic response of MCA isolated from SS rats did not constrict. Administration of a 20-HETE synthesis inhibitor, HET0016, abolished the myogenic response of MCA in CYP4A1 and SS-5(BN) rats but had no effect in SS rats. Autoregulation of CBF was impaired in SS rats compared with CYP4A1 and SS-5(BN) rats. Blood-brain barrier leakage was 5-fold higher in the brain of SS rats than in SS-5(BN) and SS.CYP4A1 rats. These findings indicate that a genetic deficiency in the formation of 20-HETE contributes to an impaired myogenic response in MCA and autoregulation of CBF in SS rats and this may contribute to vascular remodeling and cerebral injury following the onset of hypertension.
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Affiliation(s)
- Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Aron M Geurts
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Sydney R Murphy
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Mallikarjuna R Pabbidi
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Howard J Jacob
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
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IGF-1 deficiency impairs cerebral myogenic autoregulation in hypertensive mice. J Cereb Blood Flow Metab 2014; 34:1887-97. [PMID: 25248835 PMCID: PMC4269740 DOI: 10.1038/jcbfm.2014.156] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 08/06/2014] [Accepted: 08/09/2014] [Indexed: 12/16/2022]
Abstract
Aging impairs autoregulatory protection in the brain, exacerbating hypertension-induced cerebromicrovascular injury, neuroinflammation, and development of vascular cognitive impairment. Despite the importance of the age-related decline in circulating insulin-like growth factor-1 (IGF-1) levels in cerebrovascular aging, the effects of IGF-1 deficiency on functional adaptation of cerebral arteries to high blood pressure remain elusive. To determine whether IGF-1 deficiency impairs autoregulatory protection, hypertension was induced in control and IGF-1-deficient mice (Igf1(f/f)+TBG-iCre-AAV8) by chronic infusion of angiotensin-II. In hypertensive control mice, cerebral blood flow (CBF) autoregulation was extended to higher pressure values and the pressure-induced tone of middle cerebral arteries (MCAs) was increased. In hypertensive IGF-1-deficient mice, autoregulation was markedly disrupted, and MCAs did not show adaptive increases in myogenic tone. In control mice, the mechanism of adaptation to hypertension involved upregulation of TRPC channels in MCAs and this mechanism was impaired in hypertensive IGF-1-deficient mice. Likely downstream consequences of cerebrovascular autoregulatory dysfunction in hypertensive IGF-1-deficient mice included exacerbated disruption of the blood-brain barrier and neuroinflammation (microglia activation and upregulation of proinflammatory cytokines and chemokines), which were associated with impaired hippocampal cognitive function. Collectively, IGF-1 deficiency impairs autoregulatory protection in the brain of hypertensive mice, potentially exacerbating cerebromicrovascular injury and neuroinflammation mimicking the aging phenotype.
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Tzeng YC, MacRae BA, Ainslie PN, Chan GSH. Fundamental relationships between blood pressure and cerebral blood flow in humans. J Appl Physiol (1985) 2014; 117:1037-48. [DOI: 10.1152/japplphysiol.00366.2014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Cerebral blood flow responses to transient blood pressure challenges are frequently attributed to cerebral autoregulation (CA), yet accumulating evidence indicates vascular properties like compliance are also influential. We hypothesized that middle cerebral blood velocity (MCAv) dynamics during or following a transient blood pressure perturbation can be accurately explained by the windkessel mechanism. Eighteen volunteers underwent blood pressure manipulations, including bilateral thigh-cuff deflation and sit-to-stand maneuvers under normocapnic and hypercapnic (5% CO2) conditions. Pressure-flow recordings were analyzed using a windkessel analysis approach that partitions the frequency-dependent resistance and compliance contributions to MCAv dynamics. The windkessel was typically able to explain more than 50% of the MCAv variance, as indicated by R2 values for both the flow recovery and postrecovery phase. The most consistent predictors of MCAv dynamics under the control condition were the windkessel capacitive gain and high-frequency resistive gain. However, there were significant interindividual variations in the composition of windkessel predictors. Hypercapnia consistently reduced the capacitive gain and enhanced the low-frequency (0.04–0.20 Hz) resistive gain for both thigh-cuff deflation and sit-to-stand trials. These findings indicate that 1) MCAv dynamics during acute transient hypotension challenges are dominated by cerebrovascular windkessel properties independent of CA; 2) there is significant heterogeneity in windkessel properties between individuals; and 3) hemodynamic effects of hypercapnia during transient blood pressure challenges primarily reflect changes in windkessel properties rather than pure CA impairment.
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Affiliation(s)
- Y. C. Tzeng
- Cardiovascular Systems Laboratory, University of Otago, Wellington South, New Zealand
- Centre for Translational Physiology, University of Otago, Wellington South, New Zealand
| | - B. A. MacRae
- Cardiovascular Systems Laboratory, University of Otago, Wellington South, New Zealand
- Centre for Translational Physiology, University of Otago, Wellington South, New Zealand
| | - P. N. Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, British Columbia, Canada; and
| | - G. S. H. Chan
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
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Vamos Z, Ivic I, Cseplo P, Toth G, Tamas A, Reglodi D, Koller A. Pituitary adenylate cyclase-activating polypeptide (PACAP) induces relaxations of peripheral and cerebral arteries, which are differentially impaired by aging. J Mol Neurosci 2014; 54:535-42. [PMID: 24939249 DOI: 10.1007/s12031-014-0349-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/04/2014] [Indexed: 01/15/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a well-known neuropeptide, which also has vasomotor effects. However, little is known regarding its age-related and organ-specific vasomotor effects. We hypothesized that the vasomotor effects of PACAP depend on the tissue origin of the vessels and aging substantially modulates its actions. Thus, carotid (CA) and basilar arteries (BA) were isolated from young (2 months old), middle age (12 months old), and old (30 months old) rats. Their vasomotor responses were measured with an isometric myograph (DMT610M) in response to cumulative concentrations of PACAP1-38 (10(-9)-10(-6) M). PACAP1-38 induced (1) significantly greater concentration-dependent relaxations in CA compared to that of BA of young, middle age, and old rats; (2) relaxations of CA significantly decreased, whereas they did not change substantially in BA, as a function of age; (3) sodium nitroprusside (SNP)-induced relaxation did not change after PACAP1-38 administration in any conditions; and (4) inhibition of PAC1 receptors by selective PAC1 receptor blocker (PACAP6-38) completely diminished the responses to PACAP in all age groups of BA and CA. In conclusion, these findings suggest that PACAP1-38 has greater vasomotor effect in CA than that in BA, whereas aging has less effect on PACAP-induced relaxation of cerebral arteries and BA than that in peripheral arteries and CA suggesting that the relaxation to PACAP is maintained in cerebral arteries even in old age.
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Affiliation(s)
- Zoltan Vamos
- Department of Pathophysiology and Gerontology, Szentagothai Research Centre, University of Pecs, Medical School, Szigeti út 12, Pecs, 7624, Hungary
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Brew N, Walker D, Wong FY. Cerebral vascular regulation and brain injury in preterm infants. Am J Physiol Regul Integr Comp Physiol 2014; 306:R773-86. [PMID: 24647591 DOI: 10.1152/ajpregu.00487.2013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebrovascular lesions, mainly germinal matrix hemorrhage and ischemic injury to the periventricular white matter, are major causes of adverse neurodevelopmental outcome in preterm infants. Cerebrovascular lesions and neuromorbidity increase with decreasing gestational age, with the white matter predominantly affected. Developmental immaturity in the cerebral circulation, including ongoing angiogenesis and vasoregulatory immaturity, plays a major role in the severity and pattern of preterm brain injury. Prevention of this injury requires insight into pathogenesis. Cerebral blood flow (CBF) is low in the preterm white matter, which also has blunted vasoreactivity compared with other brain regions. Vasoreactivity in the preterm brain to cerebral perfusion pressure, oxygen, carbon dioxide, and neuronal metabolism is also immature. This could be related to immaturity of both the vasculature and vasoactive signaling. Other pathologies arising from preterm birth and the neonatal intensive care environment itself may contribute to impaired vasoreactivity and ineffective CBF regulation, resulting in the marked variations in cerebral hemodynamics reported both within and between infants depending on their clinical condition. Many gaps exist in our understanding of how neonatal treatment procedures and medications have an impact on cerebral hemodynamics and preterm brain injury. Future research directions for neuroprotective strategies include establishing cotside, real-time clinical reference values for cerebral hemodynamics and vasoregulatory capacity and to demonstrate that these thresholds improve long-term outcomes for the preterm infant. In addition, stimulation of vascular development and repair with growth factor and cell-based therapies also hold promise.
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Affiliation(s)
- Nadine Brew
- The Ritchie Centre, Monash Institute of Medical Research-Prince Henry's Institute, Melbourne, Clayton, Victoria, Australia; and
| | - David Walker
- The Ritchie Centre, Monash Institute of Medical Research-Prince Henry's Institute, Melbourne, Clayton, Victoria, Australia; and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Flora Y Wong
- The Ritchie Centre, Monash Institute of Medical Research-Prince Henry's Institute, Melbourne, Clayton, Victoria, Australia; and Monash Newborn, Monash Medical Centre, Melbourne, Victoria, Australia; and Department of Pediatrics, Monash University, Melbourne, Victoria, Australia
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Ellinsworth DC, Shukla N, Fleming I, Jeremy JY. Interactions between thromboxane A₂, thromboxane/prostaglandin (TP) receptors, and endothelium-derived hyperpolarization. Cardiovasc Res 2014; 102:9-16. [PMID: 24469536 DOI: 10.1093/cvr/cvu015] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Endothelium-dependent smooth muscle hyperpolarization (EDH) increasingly predominates over endothelium-derived nitric oxide (NO) as a participant in vasodilation as vessel size decreases. Its underlying nature is highly variable between vessel types, species, disease states, and exact experimental conditions, and is variably mediated by one or more transferable endothelium-derived hyperpolarizing factors and/or the electrotonic spread of endothelial hyperpolarization into the media via gap junctions. Although generally regarded (and studied) as a mechanism that is independent of NO and prostanoids, evidence has emerged that the endothelium-derived contracting factor and prostanoid thromboxane A2 can modulate several signalling components central to EDH, and therefore potentially curtail vasodilation through mechanisms that are distinct from those putatively involved in direct smooth muscle contraction. Notably, vascular production of thromboxane A2 is elevated in a number of cardiovascular disease states that promote endothelial dysfunction. This review will therefore discuss the mechanisms through which thromboxane A2 interacts with and modulates EDH, and will also consider the implications of such cross-talk in vasodilator control in health and disease.
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Affiliation(s)
- David C Ellinsworth
- Bristol Heart Institute, University of Bristol, Queens Building Level 7, Upper Maudlin St, Bristol Royal Infirmary, Upper Maudlin Street, Bristol BS2 8HW, UK
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Adenosine A1 receptors link to smooth muscle contraction via CYP4a, protein kinase C-α, and ERK1/2. J Cardiovasc Pharmacol 2013; 62:78-83. [PMID: 23519140 DOI: 10.1097/fjc.0b013e3182919591] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Adenosine A1 receptor (A1AR) activation contracts smooth muscle, although signaling mechanisms are not thoroughly understood. Activation of A1AR leads to metabolism of arachidonic acid, including the production of 20-hydroxyeicosatetraenoic acid (20-HETE) by cytochrome P4504a (CYP4a). The 20-HETE can activate protein kinase C-α (PKC-α), which crosstalks with extracellular signal-regulated kinase (ERK1/2) pathway. Both these pathways can regulate smooth muscle contraction, we tested the hypothesis that A1AR contracts smooth muscle through a pathway involving CYP4a, PKC-α, and ERK1/2. Experiments included isometric tension recordings of aortic contraction and Western blots of signaling molecules in wild type (WT) and A1AR knockout (A1KO) mice. Contraction to the A1-selective agonist 2-chloro-N cyclopentyladenosine (CCPA) was absent in A1KO mice aortae, indicating the contractile role of A1AR. Inhibition of CYP4a (HET0016) abolished 2-chloro-N cyclopentyladenosine-induced contraction in WT aortae, indicating a critical role for 20-HETE. Both WT and A1KO mice aortae contracted in response to exogenous 20-HETE. Inhibition of PKC-α (Gö6976) or ERK1/2 (PD98059) attenuated 20-HETE-induced contraction equally, suggesting that ERK1/2 is downstream of PKC-α. Contractions to exogenous 20-HETE were significantly less in A1KO mice; reduced protein levels of PKC-α, p-ERK1/2, and total ERK1/2 supported this observation. Our data indicate that A1AR mediates smooth muscle contraction via CYP4a and a PKC-α-ERK1/2 pathway.
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Age-related autoregulatory dysfunction and cerebromicrovascular injury in mice with angiotensin II-induced hypertension. J Cereb Blood Flow Metab 2013; 33:1732-42. [PMID: 23942363 PMCID: PMC3824186 DOI: 10.1038/jcbfm.2013.143] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/25/2013] [Accepted: 07/16/2013] [Indexed: 11/09/2022]
Abstract
Hypertension in the elderly substantially contributes to cerebromicrovascular damage and promotes the development of vascular cognitive impairment. Despite the importance of the myogenic mechanism in cerebromicrovascular protection, it is not well understood how aging affects the functional adaptation of cerebral arteries to high blood pressure. Hypertension was induced in young (3 months) and aged (24 months) C57/BL6 mice by chronic infusion of angiotensin II (AngII). In young hypertensive mice, the range of cerebral blood flow autoregulation was extended to higher pressure values, and the pressure-induced tone of middle cerebral artery (MCA) was increased. In aged hypertensive mice, autoregulation was markedly disrupted, and MCAs did not show adaptive increases in myogenic tone. In young mice, the mechanism of adaptation to hypertension involved upregulation of the 20-HETE (20-hydroxy-5,8,11,14-eicosatetraenoic acid)/transient receptor potential cation channel, subfamily C (TRPC6) pathway and this mechanism was impaired in aged hypertensive mice. Downstream consequences of cerebrovascular autoregulatory dysfunction in aged AngII-induced hypertensive mice included exacerbated disruption of the blood-brain barrier and neuroinflammation (microglia activation and upregulation of proinflammatory cytokines and chemokines), which were associated with impaired hippocampal dependent cognitive function. Collectively, aging impairs autoregulatory protection in the brain of mice with AngII-induced hypertension, potentially exacerbating cerebromicrovascular injury and neuroinflammation.
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Toth P, Csiszar A, Tucsek Z, Sosnowska D, Gautam T, Koller A, Schwartzman ML, Sonntag WE, Ungvari Z. Role of 20-HETE, TRPC channels, and BKCa in dysregulation of pressure-induced Ca2+ signaling and myogenic constriction of cerebral arteries in aged hypertensive mice. Am J Physiol Heart Circ Physiol 2013; 305:H1698-708. [PMID: 24097425 DOI: 10.1152/ajpheart.00377.2013] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hypertension in the elderly substantially increases the risk of stroke and vascular cognitive impairment in part due to an impaired functional adaptation of aged cerebral arteries to high blood pressure. To elucidate the mechanisms underlying impaired autoregulatory protection in aging, hypertension was induced in young (3 mo) and aged (24 mo) C57BL/6 mice by chronic infusion of angiotensin II and pressure-induced changes in smooth muscle cell (SMC) intracellular Ca(2+) concentration ([Ca(2+)]i) and myogenic constriction of middle cerebral arteries (MCA) were assessed. In MCAs from young hypertensive mice, pressure-induced increases in vascular SMC [Ca(2+)]i and myogenic tone were increased, and these adaptive responses were inhibited by the cytochrome P-450 ω-hydroxylase inhibitor HET0016 and the transient receptor potential (TRP) channel blocker SKF96365. Administration of 20- hydroxyeicosatetraenoic acid (HETE) increased SMC [Ca(2+)]i and constricted MCAs, and these responses were inhibited by SKF96365. MCAs from aged hypertensive mice did not show adaptive increases in pressure-induced calcium signal and myogenic tone and responses to HET0016 and SKF96365 were blunted. Inhibition of large-conductance Ca(2+)-activated K(+) (BK) channels by iberiotoxin enhanced SMC [Ca(2+)]i and myogenic constriction in MCAs of young normotensive animals, whereas it was without effect in MCAs of young hypertensive mice. Iberiotoxin did not restore myogenic adaptation in MCAs of aged hypertensive mice. Thus functional maladaptation of aged cerebral arteries to hypertension is due to the dysregulation of pressure-induced 20-HETE and TRP channel-mediated SMC calcium signaling, whereas overactivation of BK channels is unlikely to play a role in this phenomenon.
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Affiliation(s)
- Peter Toth
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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50
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Abstract
Cerebral blood flow is controlled by two crucial processes, cerebral autoregulation (CA) and neurovascular coupling (NVC) or functional hyperemia. Whereas CA ensures constant blood flow over a wide range of systemic pressures, NVC ensures rapid spatial and temporal increases in cerebral blood flow in response to neuronal activation. The focus of this review is to discuss the cellular mechanisms by which astrocytes contribute to the regulation of vascular tone in terms of their participation in NVC and, to a lesser extent, CA. We discuss evidence for the various signaling modalities by which astrocytic activation leads to vasodilation and vasoconstriction of parenchymal arterioles. Moreover, we provide a rationale for the contribution of astrocytes to pressure-induced increases in vascular tone via the vasoconstrictor 20-HETE (a downstream metabolite of arachidonic acid). Along these lines, we highlight the importance of the transient receptor potential channel of the vanilloid family (TRPV4) as a key molecular determinant in the regulation of vascular tone in cerebral arterioles. Finally, we discuss current advances in the technical tools available to study NVC mechanisms in the brain as it relates to the participation of astrocytes.
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