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Hosmann A, Milivojev N, Dumitrescu S, Reinprecht A, Weidinger A, Kozlov AV. Cerebral nitric oxide and mitochondrial function in patients suffering aneurysmal subarachnoid hemorrhage-a translational approach. Acta Neurochir (Wien) 2021; 163:139-149. [PMID: 32839865 PMCID: PMC7778629 DOI: 10.1007/s00701-020-04536-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 08/11/2020] [Indexed: 01/15/2023]
Abstract
Background Cerebral ischemia and neuroinflammation following aneurysmal subarachnoid hemorrhage (SAH) are major contributors to poor neurological outcome. Our study set out to investigate in an exploratory approach the interaction between NO and energy metabolism following SAH as both hypoxia and inflammation are known to affect nitric oxide (NO) metabolism and NO in turn affects mitochondria. Methods In seven patients under continuous multimodality neuromonitoring suffering poor-grade aneurysmal SAH, cerebral metabolism and NO levels (determined as a sum of nitrite plus nitrate) were determined in cerebral microdialysate for 14 days following SAH. In additional ex vivo experiments, rat cortex homogenate was subjected to the NO concentrations determined in SAH patients to test whether these NO concentrations impair mitochondrial function (determined by means of high-resolution respirometry). Results NO levels showed biphasic kinetics with drastically increased levels during the first 7 days (74.5 ± 29.9 μM) and significantly lower levels thereafter (47.5 ± 18.7 μM; p = 0.02). Only during the first 7 days, NO levels showed a strong negative correlation with brain tissue oxygen tension (r = − 0.78; p < 0.001) and a positive correlation with cerebral lactate (r = 0.79; p < 0.001), pyruvate (r = 0.68; p < 0.001), glutamate (r = 0.65; p < 0.001), as well as the lactate-pyruvate ratio (r = 0.48; p = 0.01), suggesting mitochondrial dysfunction. Ex vivo experiments confirmed that the increase in NO levels determined in patients during the acute phase is sufficient to impair mitochondrial function (p < 0.001). Mitochondrial respiration was inhibited irrespectively of whether glutamate (substrate of complex I) or succinate (substrate of complex II) was used as mitochondrial substrate suggesting the inhibition of mitochondrial complex IV. The latter was confirmed by direct determination of complex IV activity. Conclusions Exploratory analysis of our data suggests that during the acute phase of SAH, NO plays a key role in the neuronal damage impairing mitochondrial function and facilitating accumulation of mitochondrial substrate; further studies are required to understand mechanisms underlying this observation.
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Abstract
Cardiovascular disease is a major contributor to global morbidity and mortality and is the common end point of many chronic diseases. The endothelins comprise three structurally similar peptides of 21 amino acids in length. Endothelin 1 (ET-1) and ET-2 activate two G protein-coupled receptors - endothelin receptor type A (ETA) and endothelin receptor type B (ETB) - with equal affinity, whereas ET-3 has a lower affinity for ETA. ET-1 is the most potent vasoconstrictor in the human cardiovascular system and has remarkably long-lasting actions. ET-1 contributes to vasoconstriction, vascular and cardiac hypertrophy, inflammation, and to the development and progression of cardiovascular disease. Endothelin receptor antagonists have revolutionized the treatment of pulmonary arterial hypertension. Clinical trials continue to explore new applications of endothelin receptor antagonists, particularly in treatment-resistant hypertension, chronic kidney disease and patients receiving antiangiogenic therapies. Translational studies have identified important roles for the endothelin isoforms and new therapeutic targets during development, in fluid-electrolyte homeostasis, and in cardiovascular and neuronal function. Novel pharmacological strategies are emerging in the form of small-molecule epigenetic modulators, biologics (such as monoclonal antibodies for ETB) and possibly signalling pathway-biased agonists and antagonists.
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Dinet V, Petry KG, Badaut J. Brain-Immune Interactions and Neuroinflammation After Traumatic Brain Injury. Front Neurosci 2019; 13:1178. [PMID: 31780883 PMCID: PMC6861304 DOI: 10.3389/fnins.2019.01178] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 10/18/2019] [Indexed: 01/04/2023] Open
Abstract
Traumatic brain injury (TBI) is the principal cause of death and disability in children and young adults. Clinical and preclinical research efforts have been carried out to understand the acute, life-threatening pathophysiological events happening after TBI. In the past few years, however, it was recognized that TBI causes significant morbidity weeks, months, or years after the initial injury, thereby contributing substantially to the overall burden of TBI and the decrease of life expectancy in these patients. Long-lasting sequels of TBI include cognitive decline/dementia, sensory-motor dysfunction, and psychiatric disorders, and most important for patients is the need for socio-economic rehabilitation affecting their quality of life. Cerebrovascular alterations have been described during the first week after TBI for direct consequence development of neuroinflammatory process in relation to brain edema. Within the brain-immune interactions, the complement system, which is a family of blood and cell surface proteins, participates in the pathophysiology process. In fact, the complement system is part of the primary defense and clearance component of innate and adaptive immune response. In this review, the complement activation after TBI will be described in relation to the activation of the microglia and astrocytes as well as the blood-brain barrier dysfunction during the first week after the injury. Considering the neuroinflammatory activity as a causal element of neurological handicaps, some major parallel lines of complement activity in multiple sclerosis and Alzheimer pathologies with regard to cognitive impairment will be discussed for chronic TBI. A better understanding of the role of complement activation could facilitate the development of new therapeutic approaches for TBI.
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Affiliation(s)
- Virginie Dinet
- INSERM U1029, Angiogenesis and Neuroinflammation Group, University of Bordeaux, Bordeaux, France
| | - Klaus G. Petry
- INSERM U1029, Angiogenesis and Neuroinflammation Group, University of Bordeaux, Bordeaux, France
| | - Jerome Badaut
- CNRS UMR 5287, INCIA, Brain molecular Imaging Team, University of Bordeaux, Bordeaux, France
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, United States
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Bodnar CN, Roberts KN, Higgins EK, Bachstetter AD. A Systematic Review of Closed Head Injury Models of Mild Traumatic Brain Injury in Mice and Rats. J Neurotrauma 2019; 36:1683-1706. [PMID: 30661454 PMCID: PMC6555186 DOI: 10.1089/neu.2018.6127] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mild TBI (mTBI) is a significant health concern. Animal models of mTBI are essential for understanding mechanisms, and pathological outcomes, as well as to test therapeutic interventions. A variety of closed head models of mTBI that incorporate different aspects (i.e., biomechanics) of the mTBI have been reported. The aim of the current review was to compile a comprehensive list of the closed head mTBI rodent models, along with the common data elements, and outcomes, with the goal to summarize the current state of the field. Publications were identified from a search of PubMed and Web of Science and screened for eligibility following PRISMA guidelines. Articles were included that were closed head injuries in which the authors classified the injury as mild in rats or mice. Injury model and animal-specific common data elements, as well as behavioral and histological outcomes, were collected and compiled from a total of 402 articles. Our results outline the wide variety of methods used to model mTBI. We also discovered that female rodents and both young and aged animals are under-represented in experimental mTBI studies. Our findings will aid in providing context comparing the injury models and provide a starting point for the selection of the most appropriate model of mTBI to address a specific hypothesis. We believe this review will be a useful starting place for determining what has been done and what knowledge is missing in the field to reduce the burden of mTBI.
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Affiliation(s)
- Colleen N. Bodnar
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Kelly N. Roberts
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Emma K. Higgins
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Adam D. Bachstetter
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
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McBryde FD, Liu BH, Roloff EV, Kasparov S, Paton JFR. Hypothalamic paraventricular nucleus neuronal nitric oxide synthase activity is a major determinant of renal sympathetic discharge in conscious Wistar rats. Exp Physiol 2018; 103:419-428. [PMID: 29215757 DOI: 10.1113/ep086744] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 11/30/2017] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does chronic reduction of neuronally generated nitric oxide in the hypothalamic paraventricular nucleus affect the set-point regulation of blood pressure and sympathetic activity destined to the kidneys? What is the main finding and its importance? Within the hypothalamic paraventricular nucleus, nitric oxide generated by neuronal nitric oxide synthase plays a major constitutive role in suppressing long term the levels of both ongoing renal sympathetic activity and arterial pressure in conscious Wistar rats. This finding unequivocally demonstrates a mechanism by which the diencephalon exerts a tonic influence on sympathetic discharge to the kidney and may provide the basis for both blood volume and osmolality homeostasis. ABSTRACT The paraventricular nucleus (PVN) of the hypothalamus plays a crucial role in cardiovascular and neuroendocrine regulation. Application of nitric oxide donors to the PVN stimulates GABAergic transmission, and may suppress sympathetic nerve activity (SNA) to lower arterial pressure. However, the role of endogenous nitric oxide within the PVN in regulating renal SNA chronically remains to be established in conscious animals. To address this, we used our previously established lentiviral vectors to knock down neuronal nitric oxide synthase (nNOS) selectively in the PVN of conscious Wistar rats. Blood pressure and renal SNA were monitored simultaneously and continuously for 21 days (n = 14) using radio-telemetry. Renal SNA was normalized to maximal evoked discharge and expressed as a percentage change from baseline. The PVN was microinjected bilaterally with a neurone-specific tetracycline-controllable lentiviral vector, expressing a short hairpin miRNA30 interference system targeting nNOS (n = 7) or expressing a mis-sense as control (n = 7). Recordings continued for a further 18 days. The vectors also expressed green fluorescent protein, and successful expression in the PVN and nNOS knockdown were confirmed histologically post hoc. Knockdown of nNOS expression in the PVN resulted in a sustained increase in blood pressure (from 95 ± 2 to 104 ± 3 mmHg, P < 0.05), with robust concurrent sustained activation of renal SNA (>70%, P < 0.05). The study reveals a major role for nNOS-derived nitric oxide within the PVN in chronic set-point regulation of cardiovascular autonomic activity in the conscious, normotensive rat.
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Affiliation(s)
- F D McBryde
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK.,Cardiovascular Autonomic Research Cluster, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - B H Liu
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - E V Roloff
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - S Kasparov
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - J F R Paton
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK.,Cardiovascular Autonomic Research Cluster, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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Protection against Blast-Induced Traumatic Brain Injury by Increase in Brain Volume. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2075463. [PMID: 28553646 PMCID: PMC5434276 DOI: 10.1155/2017/2075463] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/13/2017] [Accepted: 03/23/2017] [Indexed: 11/18/2022]
Abstract
Blast-induced traumatic brain injury (bTBI) is a leading cause of injuries in recent military conflicts and it is responsible for an increased number of civilian casualties by terrorist attacks. bTBI includes a variety of neuropathological changes depending on the intensity of blast overpressure (BOP) such as brain edema, neuronal degeneration, diffuse axonal damage, and vascular dysfunction with neurological manifestations of psychological and cognitive abnormalities. Internal jugular vein (IJV) compression is known to reduce intracranial compliance by causing an increase in brain volume and was shown to reduce brain damage during closed impact-induced TBI. We investigated whether IJV compression can attenuate signs of TBI in rats after exposure to BOP. Animals were exposed to three 110 ± 5 kPa BOPs separated by 30 min intervals. Exposure to BOP resulted in a significant decrease of neuronal nuclei (NeuN) together with upregulation of aquaporin-4 (AQP-4), 3-nitrotyrosine (3-NT), and endothelin 1 receptor A (ETRA) expression in frontal cortex and hippocampus one day following exposures. IJV compression attenuated this BOP-induced increase in 3-NT in cortex and ameliorated the upregulation of AQP-4 in hippocampus. These results suggest that elevated intracranial pressure and intracerebral volume have neuroprotective potential in blast-induced TBI.
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Somberg LB, Gutterman DD, Miura H, Nirula R, Hatoum OA. Shock associated with endothelial dysfunction in omental microvessels. Eur J Clin Invest 2017; 47:30-37. [PMID: 27809354 DOI: 10.1111/eci.12697] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 10/30/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND Impaired microvascular function leads to a poor outcome in a variety of medical conditions. Our aim was to determine whether vasodilator responses to acetylcholine (Ach) are impaired in human omental arterioles from patients with severe trauma. MATERIALS AND METHODS Patients with massive blood loss and severe shock requiring damage control procedures were included. Tissues were collected at the first (FEL) and the second explorative laparotomy (SEL). Control tissues were collected from nontrauma patients. Freshly isolated 50-200-μm-diameter omental arterioles were analysed using videomicroscopy. Dihydroethidine and DCF-DA fluorescence were used to assess reactive oxygen species (ROS) production. MnTBAP was used to determine the contribution of excess vascular superoxide contribution to endothelial dysfunction. RESULTS After constriction (30-50%) with endothelin-1, dilation to graded doses of Ach (10-9 -10-4 M) was greater in control vessels compared to FEL and SEL (max dilation at 10-4 M (MD) = 25 ± 3%, n = 8; and 59 ± 8%, n = 8, respectively, and controls MD = 93 ± 10%, n = 6, P < 0·05). Fluorescence imaging of ROS production showed significant increases in superoxide (225·46 ± 12·86; 215·77 ± 10·75 vs. 133·75 ± 7·26, arbitrary units; P < 0·05) and peroxide-related ROS (240·8 ± 20·42; 234·59 ± 28·86, vs. 150·78 ± 15·65, arbitrary units; P < 0·05), in FEL and SEL microvessels compared to control, respectively. FEL pretreated with MnTBAP demonstrated significant improvement in Ach-induced vasodilation (25·5 ± 3·0% vs. 79·5 ± 8·2%; P < 0·05). CONCLUSIONS Severe shock associated with microvascular endothelial dysfunction enhances production of ROS in human omental tissues. The altered flow regulation may contribute to a mismatch between local blood supply and demand, exacerbating abnormal tissue perfusion and function.
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Affiliation(s)
- Lewis B Somberg
- Division of Trauma/Critical Care, Departments of Medicine and Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - David D Gutterman
- Division of Cardiovascular Medicine, Departments of Medicine and Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Hiroto Miura
- Division of Cardiovascular Medicine, Departments of Medicine and Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Raminder Nirula
- Division of Trauma/Critical Care, Departments of Medicine and Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ossama A Hatoum
- Department of Surgery B, HaEmek Medical Center, Afula, Israel.,Faculty of Medicine, Technion-Israel Institute of Technology, Afula, Israel
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Jullienne A, Obenaus A, Ichkova A, Savona-Baron C, Pearce WJ, Badaut J. Chronic cerebrovascular dysfunction after traumatic brain injury. J Neurosci Res 2016; 94:609-22. [PMID: 27117494 PMCID: PMC5415378 DOI: 10.1002/jnr.23732] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 02/11/2016] [Accepted: 02/28/2016] [Indexed: 12/12/2022]
Abstract
Traumatic brain injuries (TBI) often involve vascular dysfunction that leads to long-term alterations in physiological and cognitive functions of the brain. Indeed, all the cells that form blood vessels and that are involved in maintaining their proper function can be altered by TBI. This Review focuses on the different types of cerebrovascular dysfunction that occur after TBI, including cerebral blood flow alterations, autoregulation impairments, subarachnoid hemorrhage, vasospasms, blood-brain barrier disruption, and edema formation. We also discuss the mechanisms that mediate these dysfunctions, focusing on the cellular components of cerebral blood vessels (endothelial cells, smooth muscle cells, astrocytes, pericytes, perivascular nerves) and their known and potential roles in the secondary injury cascade. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Amandine Jullienne
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, California
| | - Andre Obenaus
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, California
- Department of Physiology, Loma Linda University School of Medicine, Loma Linda, California
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, University of California Riverside, Riverside, California
| | | | | | - William J Pearce
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California
| | - Jerome Badaut
- Department of Physiology, Loma Linda University School of Medicine, Loma Linda, California
- CNRS UMR5287, University of Bordeaux, Bordeaux, France
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Davenport AP, Hyndman KA, Dhaun N, Southan C, Kohan DE, Pollock JS, Pollock DM, Webb DJ, Maguire JJ. Endothelin. Pharmacol Rev 2016; 68:357-418. [PMID: 26956245 PMCID: PMC4815360 DOI: 10.1124/pr.115.011833] [Citation(s) in RCA: 489] [Impact Index Per Article: 61.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The endothelins comprise three structurally similar 21-amino acid peptides. Endothelin-1 and -2 activate two G-protein coupled receptors, ETA and ETB, with equal affinity, whereas endothelin-3 has a lower affinity for the ETA subtype. Genes encoding the peptides are present only among vertebrates. The ligand-receptor signaling pathway is a vertebrate innovation and may reflect the evolution of endothelin-1 as the most potent vasoconstrictor in the human cardiovascular system with remarkably long lasting action. Highly selective peptide ETA and ETB antagonists and ETB agonists together with radiolabeled analogs have accurately delineated endothelin pharmacology in humans and animal models, although surprisingly no ETA agonist has been discovered. ET antagonists (bosentan, ambrisentan) have revolutionized the treatment of pulmonary arterial hypertension, with the next generation of antagonists exhibiting improved efficacy (macitentan). Clinical trials continue to explore new applications, particularly in renal failure and for reducing proteinuria in diabetic nephropathy. Translational studies suggest a potential benefit of ETB agonists in chemotherapy and neuroprotection. However, demonstrating clinical efficacy of combined inhibitors of the endothelin converting enzyme and neutral endopeptidase has proved elusive. Over 28 genetic modifications have been made to the ET system in mice through global or cell-specific knockouts, knock ins, or alterations in gene expression of endothelin ligands or their target receptors. These studies have identified key roles for the endothelin isoforms and new therapeutic targets in development, fluid-electrolyte homeostasis, and cardiovascular and neuronal function. For the future, novel pharmacological strategies are emerging via small molecule epigenetic modulators, biologicals such as ETB monoclonal antibodies and the potential of signaling pathway biased agonists and antagonists.
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Affiliation(s)
- Anthony P Davenport
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Kelly A Hyndman
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Neeraj Dhaun
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Christopher Southan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Donald E Kohan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Jennifer S Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David M Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David J Webb
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Janet J Maguire
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
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Kallakuri S, Bandaru S, Zakaria N, Shen Y, Kou Z, Zhang L, Haacke EM, Cavanaugh JM. Traumatic Brain Injury by a Closed Head Injury Device Induces Cerebral Blood Flow Changes and Microhemorrhages. J Clin Imaging Sci 2015; 5:52. [PMID: 26605126 PMCID: PMC4629303 DOI: 10.4103/2156-7514.166354] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/09/2015] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Traumatic brain injury is a poly-pathology characterized by changes in the cerebral blood flow, inflammation, diffuse axonal, cellular, and vascular injuries. However, studies related to understanding the temporal changes in the cerebral blood flow following traumatic brain injury extending to sub-acute periods are limited. In addition, knowledge related to microhemorrhages, such as their detection, localization, and temporal progression, is important in the evaluation of traumatic brain injury. MATERIALS AND METHODS Cerebral blood flow changes and microhemorrhages in male Sprague Dawley rats at 4 h, 24 h, 3 days, and 7 days were assessed following a closed head injury induced by the Marmarou impact acceleration device (2 m height, 450 g brass weight). Cerebral blood flow was measured by arterial spin labeling. Microhemorrhages were assessed by susceptibility-weighted imaging and Prussian blue histology. RESULTS Traumatic brain injury rats showed reduced regional and global cerebral blood flow at 4 h and 7 days post-injury. Injured rats showed hemorrhagic lesions in the cortex, corpus callosum, hippocampus, and brainstem in susceptibility-weighted imaging. Injured rats also showed Prussian blue reaction products in both the white and gray matter regions up to 7 days after the injury. These lesions were observed in various areas of the cortex, corpus callosum, hippocampus, thalamus, and midbrain. CONCLUSIONS These results suggest that changes in cerebral blood flow and hemorrhagic lesions can persist for sub-acute periods after the initial traumatic insult in an animal model. In addition, microhemorrhages otherwise not seen by susceptibility-weighted imaging are present in diverse regions of the brain. The combination of altered cerebral blood flow and microhemorrhages can potentially be a source of secondary injury changes following traumatic brain injury and may need to be taken into consideration in the long-term care of these cases.
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Affiliation(s)
- Srinivasu Kallakuri
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Sharath Bandaru
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Nisrine Zakaria
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Yimin Shen
- Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Zhifeng Kou
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA ; Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Liying Zhang
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Ewart Mark Haacke
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA ; Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - John M Cavanaugh
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
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Guan DF, Ren PY, Hu W, Zhang YL. The mGluR5 Positive Allosteric Modulator CDPPB Inhibits SO2-Induced Protein Radical Formation and Mitochondrial Dysfunction Through Activation of Akt in Mouse Hippocampal HT22 Cells. Cell Mol Neurobiol 2014; 35:573-83. [DOI: 10.1007/s10571-014-0153-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/23/2014] [Indexed: 11/30/2022]
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Kallakuri S, Kreipke CW, Rossi N, Rafols JA, Petrov T. Spatial alterations in endothelin receptor expression are temporally associated with the altered microcirculation after brain trauma. Neurol Res 2013; 29:362-8. [PMID: 17626731 DOI: 10.1179/016164107x204675] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES To study the cellular distribution of endothelin receptors A and B (ETrA and ETrB) in the post-traumatic sensorimotor cortex and hippocampus. MATERIALS AND METHODS We inflicted closed head trauma to male Sprague-Dawley rats and visualized ETrA and ETrB immunoreactivity with 3,3'-diaminobenzidine. RESULTS ETrA immunolabeling was the most prominent in pyramidal neurons 24 and 48 hours post-trauma, while it reached its peak in the microvasculature at hour 4. ETrB immunolabeling was observed in endothelial cells, perivascular neurons, smooth muscle cells (SM) and pericytes, the expression being the most pronounced 24 hours post-trauma. DISCUSSION The results suggest that the vasoconstrictor effect of endothelin-1 (ET-1) is mediated primarily by ETrA. The dual effects of ETrB are reflected in its vasoconstrictor role at the vascular bed and conversely, in the attenuation of ET-1 availability and synthesis. We conclude that both receptors play a role in the disturbed microvascular autoregulation and in the sustained reduction of blood flow following trauma to the brain.
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Affiliation(s)
- Srinivasu Kallakuri
- Department of Anatomy and Cell Biology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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13
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DeGracia DJ, Kreipke CW, Kayali FM, Rafols JA. Brain endothelial HSP-70 stress response coincides with endothelial and pericyte death after brain trauma. Neurol Res 2013; 29:356-61. [PMID: 17626730 DOI: 10.1179/016164107x204666] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVES Our objective was to characterize the heat shock response (HSR) in a model of traumatic brain injury (TBI) and to determine the association of HSR to cell death. METHODS We used immunofluorescent detection of HSP-70 to characterize HSR and TUNEL labeling to determine the pattern of cell death. RESULTS HSP-70 immunofluorescence revealed a steady increase from 4 to 48 hours following TBI, culminating in a ubiquitous expression with the capillary bed 48 hours post-TBI. TUNEL labeling revealed a small subset of endothelial cell death and a most robust staining of putative pericyte cell death. DISCUSSION Our results show that while injury causes a detectable stress response, cell death is not a direct consequence of the HSR.
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Affiliation(s)
- Donald J DeGracia
- Department of Anatomy and Cell Biology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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14
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Dore-Duffy P, Wang S, Mehedi A, Katyshev V, Cleary K, Tapper A, Reynolds C, Ding Y, Zhan P, Rafols J, Kreipke CW. Pericyte-mediated vasoconstriction underlies TBI-induced hypoperfusion. Neurol Res 2012; 33:176-86. [PMID: 21801592 DOI: 10.1179/016164111x12881719352372] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Endothelin-1 is a 21-amino acid peptide that together with specific receptors, A (ETrA) and B (ETrB) is induced following traumatic brain injury (TBI) and has been closely linked to regulation of cerebral vasospasm, oxidative stress, and hypoperfusion. Specific endothelin receptor antagonists have been shown to ameliorate early evidence of neuronal cell injury, activation of microglial cells, and hypoperfusion following TBI. The exact mechanism involved in TBI-induced hypoperfusion is still unclear; however, it is thought that endothelin-1 engagement of ETrA is primarily responsible for changes in blood flow. In this study we question the role of the microvascular pericyte in endothelin-1-mediated pathophysiology in TBI. METHODS Pericyte expression of endothelin-1, ETrA, and ETrB was examined in primary culture and in sham and impacted rat brain. Adult male rats were also given intracerebroventricular injections of ETrA (BQ-123) before being subjected to TBI using a closed head acceleration impact model. RESULTS Primary pericytes express both endothelin-1 and its receptors ETrA and ETrB. Following TBI, the number of alpha-smooth muscle actin (SMA) positive pericytes located in microvessels is significantly increased by 4 hours post-traumatic impact. Increases in pericyte expression of alpha-SMA correlated with evidence of a reduction in both arteriolar and capillary diameter. Capillary endothelin-1, ETrA, and ETrB transcript and protein was also increased. Increased endothelin-1 expression was seen by 2-4 hours post-impact. Upregulation of receptors was observed by 4-8 hours and maximum by 24 hours. ETrA antagonists decreased the number of alpha-SMA(+) pericytes as well as changes in microvascular diameter. CONCLUSION These results suggest that decreased vasoconstriction following TBI may be due to an endothelin-1-induced pericyte-mediated regulation of microvessel blood flow following TBI. Furthermore, results suggest that ETrA antagonists ameliorate trauma induced hypoperfusion, in part, by inhibiting endothelin-1-mediated upregulation of alpha-SMA in pericytes.
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Affiliation(s)
- Paula Dore-Duffy
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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15
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Maegele M, Wafaisade A, Peiniger S, Braun M. The role of endothelin and endothelin antagonists in traumatic brain injury: a review of the literature. Neurol Res 2012; 33:119-26. [PMID: 21801586 DOI: 10.1179/016164111x12881719352093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES To date, there is increasing evidence for the role of endothelins in the pathophysiological development of cerebral vasospasms associated with a variety of neurological diseases, e.g., stroke and subarachnoid hemorrhage. In contrast, only little is known regarding the role of endothelins in impaired cerebral hemodynamics after traumatic brain injury. Therapeutic work in blocking the endothelin system has led to the discovery of a number of antagonists potentially useful in restoring cerebral blood flow after traumatic brain injury, potentially reducing the detrimental effects of secondary brain injury. Therefore, the present work provides an overview of background topics such as structures and biosynthesis of endothelins, different types as well as potential mechanisms and sites of action. In addition, the role of age for the effects of endothelins on cerebral hemodynamics after traumatic brain injury is discussed. RESULTS Description of data supporting the role of the endothelins play in a host of neurological deficits. CONCLUSIONS Endothelin antagonists may be effective as novel treatments for various neuropathologies.
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Affiliation(s)
- Marc Maegele
- Department of Trauma and Orthopedic Surgery, University of Witten/Herdecke, Cologne-Merheim Medical Center, Germany.
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16
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Abstract
Traumatic brain injury (TBI) is a significant cause of death and disability in both the civilian and the military populations. The primary impact causes initial tissue damage, which initiates biochemical cascades, known as secondary injury, that expand the damage. Free radicals are implicated as major contributors to the secondary injury. Our review of recent rodent and human research reveals the prominent role of the free radicals superoxide anion, nitric oxide, and peroxynitrite in secondary brain injury. Much of our current knowledge is based on rodent studies, and the authors identified a gap in the translation of findings from rodent to human TBI. Rodent models are an effective method for elucidating specific mechanisms of free radical-induced injury at the cellular level in a well-controlled environment. However, human TBI does not occur in a vacuum, and variables controlled in the laboratory may affect the injury progression. Additionally, multiple experimental TBI models are accepted in rodent research, and no one model fully reproduces the heterogeneous injury seen in humans. Free radical levels are measured indirectly in human studies based on assumptions from the findings from rodent studies that use direct free radical measurements. Further study in humans should be directed toward large samples to validate the findings in rodent studies. Data obtained from these studies may lead to more targeted treatment to interrupt the secondary injury cascades.
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Affiliation(s)
- Karen M O'Connell
- Graduate School of Nursing, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
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17
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Oliva AA, Kang Y, Sanchez-Molano J, Furones C, Atkins CM. STAT3 signaling after traumatic brain injury. J Neurochem 2012; 120:710-20. [PMID: 22145815 DOI: 10.1111/j.1471-4159.2011.07610.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Astrocytes respond to trauma by stimulating inflammatory signaling. In studies of cerebral ischemia and spinal cord injury, astrocytic signaling is mediated by the cytokine receptor glycoprotein 130 (gp130) and Janus kinase (Jak) which phosphorylates the transcription factor signal transducer and activator of transcription-3 (STAT3). To determine if STAT3 is activated after traumatic brain injury (TBI), adult male Sprague-Dawley rats received moderate parasagittal fluid-percussion brain injury or sham surgery, and then the ipsilateral cortex and hippocampus were analyzed at various post-traumatic time periods for up to 7 days. Western blot analyses indicated that STAT3 phosphorylation significantly increased at 30 min and lasted for 24 h post-TBI. A significant increase in gp130 and Jak2 phosphorylation was also observed. Confocal microscopy revealed that STAT3 was localized primarily within astrocytic nuclei. At 6 and 24 h post-TBI, there was also an increased expression of STAT3 pathway-related genes: suppressor of cytokine signaling 3, nitric oxide synthase 2, colony stimulating factor 2 receptor β, oncostatin M, matrix metalloproteinase 3, cyclin-dependent kinase inhibitor 1A, CCAAT/enhancer-binding protein β, interleukin-2 receptor γ, interleukin-4 receptor α, and α-2-macroglobulin. These results clarify some of the signaling pathways operative in astrocytes after TBI and demonstrate that the gp130-Jak2-STAT3 signaling pathway is activated after TBI in astrocytes.
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Affiliation(s)
- Anthony A Oliva
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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18
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Chatfield DA, Brahmbhatt DH, Sharp T, Perkes IE, Outrim JG, Menon DK. Juguloarterial endothelin-1 gradients after severe traumatic brain injury. Neurocrit Care 2011; 14:55-60. [PMID: 20652766 DOI: 10.1007/s12028-010-9413-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Endothelin-1 (ET-1) is a potent vasoconstrictor and is thought to be responsible for secondary ischemia and vasogenic edema after traumatic brain injury (TBI). Both CSF and plasma concentrations have been shown to be increased after TBI, but there is little evidence to confirm an intracranial site of production. METHODS Using paired arterial and jugular venous bulb sampling, we measured arterial and jugular levels of ET-1 and its precursor, big endothelin (Big ET), and calculated juguloarterial (JA) gradients for the first 5 days post-TBI. RESULTS Arterial levels of both Big ET and ET-1 were maximal on day 1 post-TBI, and decreased thereafter (P < 0.05). Arterial levels of Big ET and ET-1 showed correlation across all 5 days of the study (r(2) = 0.25, P < 0.001). While there was no significant JA gradient for Big ET, significant gradients were observed for ET-1 on days 1-4 post-TBI (P < 0.05). There was no correlation between JA gradients for Big ET and ET-1 (r(2) < 0.1, P > 0.9). These data suggest parenchymal production of ET-1 by brain tissue with spill over into the blood, rather than local intraluminal cleavage of Big ET in the cerebral vasculature. Systemic ET-1 levels and JA gradients of ET-1 were unrelated to the injury severity, APACHE II score, Marshall Grade, the presence of subarachnoid or subdural hemorrhage, or eventual outcome. CONCLUSIONS These findings confirm the synthesis of Big ET and its cleavage to ET-1 within the brain after TBI. More work is needed to elucidate the pathophysiological role and the outcome impact of ET-1 generation after TBI.
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Affiliation(s)
- Doris A Chatfield
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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19
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Rafols JA, Kreipke CW. Current brain endothelin research: a pathway to novel approaches impacting clinical trials. Neurol Res 2011; 33:115-8. [DOI: 10.1179/016164111x12881719352057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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20
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Raslan F, Schwarz T, Meuth SG, Austinat M, Bader M, Renné T, Roosen K, Stoll G, Sirén AL, Kleinschnitz C. Inhibition of bradykinin receptor B1 protects mice from focal brain injury by reducing blood-brain barrier leakage and inflammation. J Cereb Blood Flow Metab 2010; 30:1477-86. [PMID: 20197781 PMCID: PMC2949241 DOI: 10.1038/jcbfm.2010.28] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Kinins are proinflammatory and vasoactive peptides that are released during tissue damage and may contribute to neuronal degeneration, inflammation, and edema formation after brain injury by acting on discrete bradykinin receptors, B1R and B2R. We studied the expression of B1R and B2R and the effect of their inhibition on lesion size, blood-brain barrier (BBB) disruption, and inflammatory processes after a focal cryolesion of the right parietal cortex in mice. B1R and B2R gene transcripts were significantly induced in the lesioned hemispheres of wild-type mice (P<0.05). The volume of the cortical lesions and neuronal damage at 24 h after injury in B1R(-/-) mice were significantly smaller than in wild-type controls (2.5+/-2.6 versus 11.5+/-3.9 mm(3), P<0.001). Treatment with the B1R antagonist R-715 1 h after lesion induction likewise reduced lesion volume in wild-type mice (2.6+/-1.4 versus 12.2+/-6.1 mm(3), P<0.001). This was accompanied by a remarkable reduction of BBB disruption and tissue inflammation. In contrast, genetic deletion or pharmacological inhibition of B2R had no significant impact on lesion formation or the development of brain edema. We conclude that B1R inhibition may offer a novel therapeutic strategy after acute brain injuries.
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Affiliation(s)
- Furat Raslan
- Department of Neurosurgery, University of Würzburg, Würzburg, Germany
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21
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Brain cellular localization of endothelin receptors A and B in a rodent model of diffuse traumatic brain injury. Neuroscience 2010; 168:820-30. [DOI: 10.1016/j.neuroscience.2010.01.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Revised: 12/23/2009] [Accepted: 01/11/2010] [Indexed: 01/23/2023]
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22
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Toda N, Ayajiki K, Okamura T. Cerebral Blood Flow Regulation by Nitric Oxide: Recent Advances. Pharmacol Rev 2009; 61:62-97. [DOI: 10.1124/pr.108.000547] [Citation(s) in RCA: 268] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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An analysis of regional microvascular loss and recovery following two grades of fluid percussion trauma: a role for hypoxia-inducible factors in traumatic brain injury. J Cereb Blood Flow Metab 2009; 29:575-84. [PMID: 19088740 DOI: 10.1038/jcbfm.2008.151] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Secondary hypoxic/ischemic injuries, stemming from reductions in cerebral blood flow are important contributing factors in progressive neuronal dysfunction after brain trauma. A greater preclinical understanding of how brain trauma leads to secondary hypoxia/ischemia is necessary in the development of posttraumatic brain injury (TBI) therapeutics. To this end, we examined the density of microvascular coverage in the injured and contralateral cortical hemispheres using two intensities of fluid percussion trauma in rats. A silicone microangiography technique showed a significant loss in microvascular density in 2 atmosphere (atm) (16.9+/-3.8%) and 3 atm (15.7+/-1.3%) injured animals relative to sham animals (29.9+/-2.5%; P<0.01). RECA-1 immunohistochemistry indicated that capillary changes involved a reduction in capillary number and diameter. Reduction in microvascular density was shown to be a diffuse phenomenon occurring up to 4 mm rostral and caudal to the injury epicenter. Recovery of microvasculature occurred by 2 weeks after injury only in the 2 atm injury group. Expression of HIF1alpha and increased vascular endothelial growth factor expression were observed in the ipsilateral hippocampus suggesting sufficiently impaired microcirculation resulting in the expression of hypoxic-response proteins. Collectively, the results indicate diffuse and heterogeneous microvascular alterations as well as endogenous expression of neuroprotective and neovascularization pathways after TBI.
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Kreipke CW, Rafols JA. Calponin control of cerebrovascular reactivity: therapeutic implications in brain trauma. J Cell Mol Med 2009; 13:262-9. [PMID: 19278456 PMCID: PMC3823353 DOI: 10.1111/j.1582-4934.2008.00508.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 09/25/2008] [Indexed: 01/04/2023] Open
Abstract
Calponin (Cp) is an actin-binding protein first characterized in chicken gizzard smooth muscle (SM). This review discusses the role of Cp in mediating SM contraction, the biochemical process by which Cp facilitates SM contraction and the function of Cp in the brain. Recent work on the role of Cp in pathological states with emphasis on traumatic brain injury is also discussed. Based on past and present data, the case is presented for targeting Cp for novel genetic and pharmacological therapies aimed at improving outcome following traumatic brain injury (TBI).
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Affiliation(s)
- Christian W Kreipke
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, MI, USA
| | - Jose A Rafols
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, MI, USA
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25
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Abstract
Head injury remains a major cause of preventable death and serious morbidity in young adults. Based on the available evidence, it appears that a cerebral perfusion pressure of 50 to 70 mm Hg is generally adequate to ensure cerebral oxygen delivery and prevent ischemia. However, evidence suggests that perfusion requirements may not only vary across the injured brain but also differ depending on the time since injury. Such heterogeneity, both within and between subjects, suggests that individualized therapy may be an appropriate treatment strategy. Future studies should aim to assess which groups of patients, and what regional pathophysiological derangements, may benefit with improvements in functional outcome from therapeutic increases or decreases in cerebral perfusion pressure beyond these proposed limits. Such functional improvements may be of immense importance to patients and require formal neurocognitive assessments to discriminate improvements.
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Affiliation(s)
- Monica Trivedi
- Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Jonathan P. Coles
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom, Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom,
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du Plessis AJ. Cerebrovascular injury in premature infants: current understanding and challenges for future prevention. Clin Perinatol 2008; 35:609-41, v. [PMID: 19026331 DOI: 10.1016/j.clp.2008.07.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cerebrovascular insults are a leading cause of brain injury in premature infants, contributing to the high prevalence of motor, cognitive, and behavioral deficits. Understanding the complex pathways linking circulatory immaturity to brain injury in premature infants remains incomplete. These mechanisms are significantly different from those causing injury in the mature brain. The gaps in knowledge of normal and disturbed cerebral vasoregulation need to be addressed. This article reviews current understanding of cerebral perfusion, in the sick premature infant in particular, and discusses challenges that lie ahead.
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Affiliation(s)
- Adré J du Plessis
- Department of Neurology, Children's Hospital Boston, Boston, MA 02115, USA.
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27
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Rafols JA, Kreipke CW, Petrov T. Alterations in cerebral cortex microvessels and the microcirculation in a rat model of traumatic brain injury: a correlative EM and laser Doppler flowmetry study. Neurol Res 2007; 29:339-47. [PMID: 17626728 DOI: 10.1179/016164107x204648] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES We sought to establish the temporal association of fluctuations in cortical cerebral blood flow (CBF) with ultrastructural alterations of microvessels in rat sensorimotor cortex (smCx) following administration of a rodent acceleration impact model of traumatic brain injury (TBI). METHODS Laser Doppler flowmetry (LDF) and electron microscopy (EM) were used in parallel experiments that lasted for up to 48 hours after induction of TBI. RESULTS Compared to sham-operated control, there was a 37% reduction of cortical CBF between 12 and 24 hours, this reduction remaining unchanged for up to 48 hours post-TBI. Ultrastructural alterations in the lumen and wall of smCx microvessels, including endothelial cell distortion and luminal collapse, were seen at hour 1 and continued up to 48 hours after trauma. Compared to control, there was a 40% decrease in the average microvascular luminal area 4 hours and a trend to recover (21%) by 48 hours after trauma. Smooth muscle (SM) in the wall of reacting microvessels showed evidence of increase contractility that coincided temporally with the decreased perfusion of cortical CBF. DISCUSSION Based on these observations, it is proposed that TBI causes alterations in the vascular tone of reacting microvessels which leads to prolonged vasoreactivity and restriction of the lumen in many but not all microvessels.
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Affiliation(s)
- José A Rafols
- Department of Anatomy and Cell Biology, Scott Hall, Room No. 9312, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA.
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Kreipke CW, Morgan R, Kallakuri S, Rafols JA. Behavioral pre-conditioning enhances angiogenesis and cognitive outcome after brain trauma. Neurol Res 2007; 29:388-94. [PMID: 17626735 DOI: 10.1179/016164107x204710] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES In this study, we used Marmarou's model of traumatic brain injury (TBI) and sought to determine: (1) the effect of TBI on cognitive outcome measured on a radial arm maze; (2) the effect of behavioral conditioning before TBI, i.e. pre-conditioning, on cognitive outcome; (3) the effect of pre-conditioning on angiogenesis. METHODS Cognitive outcome was measured by performance on an eight-arm radial maze. Behavioral conditioning consisted of daily exposure of animals to the radial arm maze. Latency and number of errors were recorded as an index of overall performance and acquisition of the test. Extent of angiogenesis was measured by vascular endothelial growth factor receptor 2 (VEGFR2) immunofluorescence and by determining capillary density. RESULTS Our results indicated that trauma alone causes significant cognitive impairments. Pre-conditioning caused a marked improvement in radial arm maze performance following injury. These results coincide with both a significant increase in VEGFR2 expression and increased capillary density within the cortex and hippocampus. DISCUSSION TBI causes significant impairments in cognition. These deficits can be ameliorated using a pre-conditioning paradigm. While the precise mechanism has yet to be elucidated, our results indicate that angiogenesis may underlie the cognitive sparing seen in pre-conditioned animals.
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Affiliation(s)
- Christian W Kreipke
- Department of Anatomy and Cell Biology, Scott Hall, Room No. 9312, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA
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29
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Hüttemann M, Lee I, Kreipke CW, Petrov T. Suppression of the inducible form of nitric oxide synthase prior to traumatic brain injury improves cytochrome c oxidase activity and normalizes cellular energy levels. Neuroscience 2007; 151:148-54. [PMID: 18037245 DOI: 10.1016/j.neuroscience.2007.09.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 09/11/2007] [Accepted: 10/11/2007] [Indexed: 01/09/2023]
Abstract
We have previously shown that the observed immediate increase in nitric oxide (NO) plays a significant role in the control of the cerebral microcirculation following traumatic brain injury (TBI). However, a second consequence of increased NO production after TBI may be impaired mitochondrial function, due to the fact that NO is a well-known inhibitor of cytochrome c oxidase (CcO). CcO is a key enzyme of the mitochondrial oxidative phosphorylation (OxPhos) machinery, which creates cellular energy in the form of ATP. NO competes with oxygen at the heme a(3)-Cu(B) reaction center of CcO. We thus hypothesized that TBI triggers inhibition of CcO, which would in turn lead to a decreased energy production by OxPhos at a time of an elevated energy demand for tissue remodeling. Here we show that TBI as induced by an acceleration weight drop model of diffuse brain injury in rats leads to CcO inhibition and dramatically decreased ATP levels in brain cortex. CcO inhibition can be partially restored by application of iNOS antisense oligonucleotides prior to TBI, which leads to a normalization of ATP levels similar to the controls. We propose that a lack of energy after TBI caused by inhibition of CcO is an important aspect of trauma pathology.
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Affiliation(s)
- M Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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30
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Kreipke CW, Morgan RL, Petrov T, Rafols JA. Subcellular redistribution of calponin underlies sustained vascular contractility following traumatic brain injury. Neurol Res 2007; 29:604-9. [PMID: 17535561 DOI: 10.1179/016164107x166317] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVES The purpose of this study was to observe temporal changes in calponin (Cp), a contractile protein, in response to traumatic brain injury (TBI). METHODS Double immunocytochemistry in conjunction with morphometric methods was used to study Cp temporal migration in smooth muscle cells (SM) of reacting microvessels following TBI, as induced using a weight-drop, acceleration impact method. RESULTS Quantification of migrated Cp in the SM wall after TBI was carried out on three-dimensional orthographic reconstructions of serial, digitally acquired images and optical densitometry. Color shifts in Cp intensity were measured in three arbitrary longitudinal compartments, luminal (lu), middle (m) and abluminal (ablu), of SM cytoplasm with respect to proximity to the vessel's lumen. By 24 and 48 hours after TBI, most Cp had migrated from the SM compartment closest to the lu to that farthest away or ablu. In addition, a qualitative increase in Cp was detected closest to the ablu compartment in those segments of the vessel severely constricted. DISCUSSION Cp migration from cytoskeletal to contractile regions of SM supports its role both in the initiation of vessel contractility and its interaction with cytoskeletal structures subjacent to the cell membrane in SM's contracted state.
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Affiliation(s)
- Christian W Kreipke
- Department of Anatomy and Cell Biology, Scott Hall, Room No. 9312, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA
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Maier B, Lehnert M, Laurer HL, Marzi I. Biphasic elevation in cerebrospinal fluid and plasma concentrations of endothelin 1 after traumatic brain injury in human patients. Shock 2007; 27:610-4. [PMID: 17505299 DOI: 10.1097/shk.0b013e31802f9eaf] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Severe traumatic brain injury (TBI) is characterized by a high mortality and poor outcome. The pathomechanisms involved are cytokine-mediated proinflammatory and anti-inflammatory reactions and significant cerebral microcirculatory disorders. The role of endothelin 1 (ET-1), a very potent vasoconstrictive peptide, in the deterioration of cerebral perfusion after trauma is still unclear. The presented study investigated the changes in ET-1 in the cerebrospinal fluid (CSF) and plasma after TBI in humans, with special regard to the presence of subarachnoid hemorrhage (SAH) and clinical outcome. Twenty patients with TBI were consecutively enrolled into the study, 10 patients without SAH (TBI group) and 10 patients with SAH (TBI-H group). Paired samples of plasma and CSF were collected for 10 days after trauma. Analysis of the ET-1 concentrations showed that TBI is associated with initially increased ET-1 values in plasma (TBI, day 1; TBI-H, days 2-3) and significantly increased (P < 0.05, vs. control) CSF concentrations (TBI, days 1-2; TBI-H, days 1-3) in the first days after trauma. In the further time course, ET-1 values declined in both groups, reaching reference values in plasma. The CSF values remained significantly (P < 0.05 vs. control) elevated. Both groups showed a second peak on the beginning of the second week after trauma in plasma and CSF. Whereas plasma concentrations failed to reach significance, CSF values showed a significant peak on day 7 in both groups. The TBI-H patients had significantly (P < 0.05) higher values in the secondary peak compared with patients of the TBI group. The kinetics of traumatic SAH-dependent ET-1 needs to be assessed in further investigations.
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Affiliation(s)
- Bernd Maier
- Department of Trauma, Hand, and Reconstructive Surgery, Medical School of the Johann Wolfgang Goethe University, D-60590 Frankfurt/Main, Germany.
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Henze D, Menzel M, Soukup J, Scharf A, Holz C, Németh N, Hanisch F, Clausen T. Endothelin-1 and cerebral blood flow in a porcine model. J Clin Neurosci 2007; 14:650-7. [PMID: 17532501 DOI: 10.1016/j.jocn.2006.05.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Accepted: 05/30/2006] [Indexed: 11/28/2022]
Abstract
The purpose of the study was to investigate whether provoked changes of cerebral perfusion pressure and arterial carbon dioxide tension are able to influence the cerebral metabolism of endothelin-1 (ET-1) in a porcine model. Brain tissue oxygen tension, regional cerebral blood flow and mean arterial blood pressure were monitored in 10 healthy pigs during induced hyperventilation (HV), hypertension (HrT) and hypotension (HoT). ET-1 was determined in the arterial and cerebrovenous blood. Microdialysis samples (lactate, glucose and pyruvate) were taken from brain and subcutaneous tissue. A significant decrease (p<0.05) of the arterial ET-1 (1.46+/-0.33 fmol/mL) compared to the baseline (2.18+/-0.36 fmol/mL) was observed after the HoT-period. We detected a positive correlation between cerebrovenous ET-1 and extracellular cerebral glucose (0.68; p<0.05) after the baseline as well as a negative correlation of -0.81 (p<0.005) between the cerebrovenous ET-1 level and the extracellular cerebral lactate after the HoT-period. These data imply that with increasingly pathological changes of the cerebral metabolism endothelin becomes progressively more important in the regulation of cerebral vascular tone.
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Affiliation(s)
- Dirk Henze
- Department of Anaesthesiology and Intensive Care Medicine, Martin-Luther-University Halle-Wittenberg, Dryanderstr. 4-7, 06108 Halle (Saale), Germany.
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Kreipke CW, Morgan R, Roberts G, Bagchi M, Rafols JA. Calponin phosphorylation in cerebral cortex microvessels mediates sustained vasoconstriction after brain trauma. Neurol Res 2007; 29:369-74. [PMID: 17626732 DOI: 10.1179/016164107x204684] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES The purpose of this study was to determine the molecular and biochemical changes in the contractile protein, calponin (Cp), which temporally coincide with a previously reported state of sustained contractility following traumatic brain injury (TBI). METHODS Double immunofluorescence, western analysis and two-dimensional non-equilibrium pH gradient gel electrophoresis (NEPHGE)/SDS-PAGE techniques were utilized to determine both the location and extent of Cp within smooth muscle cells (SM) and the phosphorylation state of Cp following TBI, as induced using a weight drop acceleration impact model. RESULTS Double immunofluorescence for Cp and SM indicate that following injury, Cp migrates from the cytosol to a location subjacent to the SM membrane. Western analysis revealed a significant increase in Cp protein expression following injury that was maintained up to 48 hours post-injury. Combined Western analysis and NEPHGE indicated that Cp is phosphorylated following TBI. DISCUSSION Cp migration and phosphorylation may underlie the mechanism for increased vasoreactivity leading to hypoperfusion following TBI.
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Affiliation(s)
- Christian W Kreipke
- Department of Anatomy and Cell Biology, Scott Hall, Room No. 9312, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA
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Shen Y, Kou Z, Kreipke CW, Petrov T, Hu J, Haacke EM. In vivo measurement of tissue damage, oxygen saturation changes and blood flow changes after experimental traumatic brain injury in rats using susceptibility weighted imaging. Magn Reson Imaging 2006; 25:219-27. [PMID: 17275617 DOI: 10.1016/j.mri.2006.09.018] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2006] [Accepted: 09/15/2006] [Indexed: 12/31/2022]
Abstract
Traumatic brain injury (TBI) is a prevalent disease, and many TBI patients experience disturbed cerebral blood flow (CBF) after injury. Moreover, TBI is difficult to quantify with conventional imaging modalities. In this paper, we utilized susceptibility weighted imaging (SWI) as a means to monitor functional blood oxygenation changes and to quantify CBF changes in animals after trauma. In this study using six rats, brain trauma was induced by a weight drop model and the brain was scanned over four time points: pre trauma, and 4 h, 24 h and 48 h post trauma. Five rats survived and one died after trauma. A blood phase analysis using filtered SWI phase images suggested that three rats recovered after 48 h and two rats deteriorated. SWI also suggested that CBF decreased by up to 26%. The CBF change is in agreement with the results of arterial spin labeling methods conducted in this study and with previously published results. Furthermore, SWI revealed an enlargement of the major venous vasculature in deep brain structures, in accordance with the location of diffuse axonal injury. Compared with the traditional, invasive, clinical monitoring of cerebral vascular damage and reduction in blood flow, this method offers a novel, safe and noninvasive approach to quantify changes in oxygen saturation and CBF and to visualize structural changes in blood vasculature after TBI.
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Affiliation(s)
- Yimin Shen
- Department of Radiology, Wayne State University, Detroit, MI 48201, USA
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Kreipke CW, Morgan NC, Petrov T, Rafols JA. Calponin and caldesmon cellular domains in reacting microvessels following traumatic brain injury. Microvasc Res 2006; 71:197-204. [PMID: 16635497 DOI: 10.1016/j.mvr.2006.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Revised: 01/11/2006] [Accepted: 02/09/2006] [Indexed: 01/16/2023]
Abstract
Calponin (Cp) and caldesmon (Cd) are actin-binding proteins involved in the regulation of smooth muscle (SM) tone during blood vessel contraction. While in vitro studies have reported modifications of these proteins during vessel contractility, their role in vivo remains unclear. Traumatic brain injury (TBI) causes disruption of cerebral microvascular tone, leading to sustained contractility in reacting microvessels and cerebral hypoperfusion. This study aimed to determine the spatial and temporal expressions of Cp and Cd in rat cerebral cortical and hippocampal microvessels post-TBI. Reacting microvessels were analyzed in control, 4, 24, and 48 h post-injury. Single and double immunocytochemical techniques together with semiquantitative analyses revealed a Cp upregulation in SM at all time frames post-TBI; with the protein migrating from SM cytosol to the vicinity of the cell membrane. Similarly, Cd immunoreactivity significantly increased in both SM and endothelial cells (En). However, while Cp and Cd in SM remained elevated, their levels in En returned to normal at 48 h post-TBI. The results suggest that Cp and Cd levels increase while compartmentalizing to specific subcellular domains. These changes are temporally associated with modifications in the cytoskeleton and contractile apparatus of SM and En during blood vessel contractility. Furthermore, these changes may underlie the state of sustained contractility and hypoperfusion observed in reacting microvessels after TBI.
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Affiliation(s)
- Christian W Kreipke
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Abstract
The cerebrovascular endothelium exerts a profound influence on cerebral vessels and cerebral blood flow. This review summarizes current knowledge of various dilator and constrictor mechanisms intrinsic to the cerebrovascular endothelium. The endothelium contributes to the resting tone of cerebral arteries and arterioles by tonically releasing nitric oxide (NO•). Dilations can occur by stimulated release of NO•, endothelium-derived hyperpolarization factor, or prostanoids. During pathological conditions, the dilator influence of the endothelium can turn to that of constriction by a variety of mechanisms, including decreased NO• bioavailability and release of endothelin-1. The endothelium may participate in neurovascular coupling by conducting local dilations to upstream arteries. Further study of the cerebrovascular endothelium is critical for understanding the pathogenesis of a number of pathological conditions, including stroke, traumatic brain injury, and subarachnoid hemorrhage.
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Affiliation(s)
- Jon Andresen
- Department of Anesthesiology, Baylor College of Medicine, One Baylor Plaza, Suite 434D, Houston, Texas 77030, USA.
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Santos A, Borges N, Cerejo A, Sarmento A, Azevedo I. Catalase Activity and Thiobarbituric Acid Reactive Substances (TBARS) Production in a Rat Model of Diffuse Axonal Injury. Effect of Gadolinium and Amiloride. Neurochem Res 2005; 30:625-31. [PMID: 16176066 DOI: 10.1007/s11064-005-2750-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study evaluated the effect of mechanogated membrane ion channel blockers on brain catalase (CAT) activity and thiobarbituric acid reactive substances (TBARS) production after traumatic brain injury (TBI). A weight drop trauma model was used. Controls were sham-operated and received no weight drop. Gadolinium (GAD) or amiloride (AMI) were administered to control and experimental rats (30 min after TBI). Brain CAT activity and TBARS production were measured. When blood vessels were washed out with saline perfusion brain CAT activity significantly increased up to 6 h after trauma, decreasing significantly by 24 h; GAD or AMI administration preserved CAT activity 24 h after TBI. TBARS production increased after trauma, this effect being significantly reversed by GAD or AMI administration. GAD significantly decreased TBARS production in control animals. Mechanogated membrane ion channels may be involved in the genesis of the ionic disruption leading to oxidative stress and other secondary injury processes in head trauma.
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Affiliation(s)
- Alejandro Santos
- Serviço de Bioquímica (U38-FCT) Faculdade de Medicina, Universidade do Porto, 4200-319, Porto, Portugal.
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Steiner J, Rafols D, Park HK, Katar MS, Rafols JA, Petrov T. Attenuation of iNOS mRNA exacerbates hypoperfusion and upregulates endothelin-1 expression in hippocampus and cortex after brain trauma. Nitric Oxide 2005; 10:162-9. [PMID: 15158696 DOI: 10.1016/j.niox.2004.03.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 03/22/2004] [Indexed: 10/26/2022]
Abstract
Nitric oxide (NO, a vasodilator) and endothelin-1 (ET-1, a powerful vasoconstrictor) participate in the regulation of brain's microcirculation influencing each other's expression and synthesis. Following injury to the brain, NO is derived largely from the inducible form of nitric oxide synthase (iNOS). We used Marmarou's model of traumatic brain injury (TBI) to study the cerebral blood flow and expression (mRNA) of ET-1 in rats that were pretreated with antisense iNOS oligodeoxynucleotides (ODNs). Intracerebroventricular application of iNOS ODNs resulted in reduced synthesis of iNOS as detected by Western blot analysis. The cerebral blood flow (measured by laser Doppler flowmetry), generally decreased after TBI, was further markedly reduced in the treated animals and remained at low levels up to 48 h post-TBI. The expression of ET-1 (detected by in situ hybridization in cortex and hippocampus) was increased 2-3-fold following TBI alone and this increase reached 5-6-fold in animals pretreated with antisense iNOS ODNs. The results indicate that most likely, NO, generated primarily by iNOS, suppresses ET-1 production and that a decrease of NO results in upregulation of ET-1 via transcriptional and translational mechanisms. Increased availability of ET-1 at the vascular bed and the neuropil may contribute to the altered microvascular reactivity and reduced perfusion of the brain following TBI.
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Affiliation(s)
- J Steiner
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, 540 East Canfield Ave., Detroit, MI 48201, USA
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41
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Abstract
Nitric oxide (NO) is a gaseous chemical messenger which has functions in the brain in a variety of broad physiological processes, including control of cerebral blood flow, interneuronal communications, synaptic plasticity, memory formation, receptor functions, intracellular signal transmission, and release of neurotransmitters. As might be expected from the numerous and complex roles that NO normally has, it can have both beneficial and detrimental effects in disease states, including traumatic brain injury. There are two periods of time after injury when NO accumulates in the brain, immediately after injury and then again several hours-days later. The initial immediate peak in NO after injury is probably due to the activity of endothelial NOS and neuronal NOS. Pre-injury treatment with 7-nitroindazole, which probably inhibits this immediate increase in NO by neuronal NOS, is effective in improving neurological outcome in some models of traumatic brain injury (TBI). After the initial peak in NO, there can be a period of relative deficiency in NO. This period of low NO levels is associated with a low cerebral blood flow (CBF). Administration of L-arginine at this early time improves CBF, and outcome in many models. The late peak in NO after traumatic injury is probably due primarily to the activity of inducible NOS. Inhibition of inducible NOS has neuroprotective effects in most models.
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Affiliation(s)
- Leela Cherian
- Department of Neurosurgery, Baylor College of Medicine, 6560 Fannin St, #944, Houston, Texas 77030, USA
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Atan MS, Moochhala SM, Ng KC, Low K, Teo AL, Lu J. Effects of aminoguanidine and l-arginine methyl ester resuscitation following induction of fluid percussion injury and severe controlled hemorrhagic shock in the rat brain. J Neurosurg 2004; 101:138-44. [PMID: 15255264 DOI: 10.3171/jns.2004.101.1.0138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. In this study the authors compared the effects of both a selective inducible nitric oxide synthase (iNOS) inhibitor and a nonselective inhibitor on posttraumatic recovery and neuron survival by using a combined model of lateral fluid percussion injury (FPI) and hemorrhagic shock (HS).
Methods. Male Sprague—Dawley rats weighing 300 to 350 g underwent FPI to the brain (3.5 atm) and hemorrhage to a mean arterial blood pressure (MABP) of 40 mm Hg for 1 hour. Rats were then resuscitated during 1 hour with bolus infusions of aminoguanidine (AG) or nitro-l-arginine methyl ester (l-NAME). Neuronal apoptosis was determined by performing Nissl staining and in situ terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate nick-end labeling technique. Rats infused with AG showed a significant increase in mean survival time and cerebral tissue perfusion, although the MABP and nitrate/nitrite levels did not significantly change compared with those in l-NAME—treated rats even though both animal groups had been subjected to combined FPI and HS, FPI alone, or HS alone. Furthermore, infusion of AG also significantly decreased the number of apoptotic neurons when compared with the number in rats treated with l-NAME.
Conclusions. The authors asserted that treatment with AG, which causes the inhibition of iNOS, might contribute to improved physiological parameters and neuronal cell survival following FPI and HS.
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Affiliation(s)
- Md Shirhan Atan
- Department of Pharmacology, National University of Singapore, Singapore
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Lundblad C, Grände PO, Bentzer P. A Mouse Model for Evaluation of Capillary Perfusion, Microvascular Permeability, Cortical Blood Flow, and Cortical Edema in the Traumatized Brain. J Neurotrauma 2004; 21:741-53. [PMID: 15253802 DOI: 10.1089/0897715041269614] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Genetically engineered mice have successfully been used to investigate molecular and cellular mechanisms associated with cell dysfunction following brain trauma. Such animals may also offer a possibility to investigate mechanisms involved in posttraumatic hemodynamic alterations. The objective of the study was to establish a mouse model in which important hemodynamic alterations following trauma could be analyzed. C57/BL6 male mice were subjected to controlled cortical impact injury (CCI) or sham-injury. Distribution of blood flow was estimated by determining number of perfused capillaries using FITC-dextran as an intravascular marker. Cortical blood flow was measured using [(14)C]-iodoantipyrine, brain water content (BWC) was measured using a wet vs. dry weight method, and permeability surface area product (PS) was estimated by the transfer constant for [(51)Cr]-EDTA. Number of perfused capillaries in the contusion area was progressively reduced during the first 24 h following trauma by at most 60% relative to a value of 329 +/- 61/mm(2) in sham-injured animals. Blood flow in the contusion area decreased simultaneously by at most 50% relative to a control value of 1.8 +/- 0.4 mL.min(-1).g(-1), and was reduced further in subregions within the contusion area. BWC in the injured hemisphere increased from 79.3 +/- 0.5% at control to at most 79.9 +/- 0.6% at 24 h post trauma. PS in the injured hemisphere increased by 71% at 3 h post trauma relative to a control value of 0.45 +/- 0.1 microL.min(-1).g(-1), and was close to control at 24 h. The present study demonstrates that brain trauma in addition to a reduction in cortical blood flow, reduces number of perfused capillaries, which most likely affects exchange of nutrients and fluid. The CCI in mouse is likely to be a useful tool to elucidate mechanisms involved in hemodynamic alterations following brain trauma.
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Affiliation(s)
- C Lundblad
- Department of Physiological Sciences, University of Lund and Lund University Hospital, Lund, Sweden.
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McArthur DL, Chute DJ, Villablanca JP. Moderate and severe traumatic brain injury: epidemiologic, imaging and neuropathologic perspectives. Brain Pathol 2004; 14:185-94. [PMID: 15193031 PMCID: PMC8095962 DOI: 10.1111/j.1750-3639.2004.tb00052.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
This article examines 3 contexts in which moderate or severe traumatic brain injury can be approached. The epidemiologic background of moderate and severe traumatic brain injury is presented, with particular attention paid to new findings from the study of a national hospital inpatient database. We review aspects of neuroimaging and how new imaging modalities can reveal fine detail about traumatic brain injury. Finally we examine the current state of neuropathologic evaluation of, and recent developments in, understanding of the neural disruptions that occur following traumatic brain injury, together with cellular reactions to these disruptions.
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Affiliation(s)
- David L McArthur
- Division of Neurosurgery, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA 90095-1752, USA.
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DeWitt DS, Prough DS. Traumatic Cerebral Vascular Injury: The Effects of Concussive Brain Injury on the Cerebral Vasculature. J Neurotrauma 2003; 20:795-825. [PMID: 14577860 DOI: 10.1089/089771503322385755] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In terms of human suffering, medical expenses, and lost productivity, head injury is one of the major health care problems in the United States, and inadequate cerebral blood flow is an important contributor to mortality and morbidity after traumatic brain injury. Despite the importance of cerebral vascular dysfunction in the pathophysiology of traumatic brain injury, the effects of trauma on the cerebral circulation have been less well studied than the effects of trauma on the brain. Recent research has led to a better understanding of the physiologic, cellular, and molecular components and causes of traumatic cerebral vascular injury. A more thorough understanding of the direct and indirect effects of trauma on the cerebral vasculature will lead to improvements in current treatments of brain trauma as well as to the development of novel and, hopefully, more effective therapeutic strategies.
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Affiliation(s)
- Douglas S DeWitt
- Charles R. Allen Research Laboratories, Department of Anesthesiology, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0830, USA.
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Rodríguez-Baeza A, Reina-de la Torre F, Poca A, Martí M, Garnacho A. Morphological features in human cortical brain microvessels after head injury: a three-dimensional and immunocytochemical study. THE ANATOMICAL RECORD. PART A, DISCOVERIES IN MOLECULAR, CELLULAR, AND EVOLUTIONARY BIOLOGY 2003; 273:583-93. [PMID: 12808643 DOI: 10.1002/ar.a.10069] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We studied the morphology of cortical microvessels in the brains of 10 patients who had died after receiving a traumatic head injury (THI). Scanning electron microscopy (SEM) of vascular corrosion casts, confocal microscopy of histological sections after immunocytochemistry, and detection of apoptosis by terminal dUTP nick end labeling (TUNEL) were used. Microvascular casts showed an angioarchitectonic distribution that was defined as normal according to results obtained in a previous, nontraumatic series of subjects. However, when we compared them with previous works, the cast surface of some of the microvessels showed three types of morphological alterations: longitudinal folds, sunken surfaces with craters, and a significant flattening with reduction of lumen. The vessels that were primarily affected were the arterioles and capillaries of the middle and deep cortical vascular zones. Immunostaining with the monoclonal antibody MAS-336 against endothelial cells also showed the presence of longitudinal folds with a thinning of the vascular lumen, cytoplasmic round bodies, and a thickening of the endothelial cell membrane. The TUNEL technique revealed a positive staining of some endothelial cells. The structural alterations we observed indicate that microvessels undergo endothelial cell damage after THI. We suggest that this kind of lesion and the secondary functional injury to the blood-brain barrier (BBB) could play an important role in the development of the secondary lesions that these patients show in the subacute phase.
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Affiliation(s)
- Alfonso Rodríguez-Baeza
- Department of Morphological Sciences, Anatomy and Embryology Unit, Faculty of Medicine, Autonomous University of Barcelona, Barcelona, Spain.
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Steiner LA, Coles JP, Czosnyka M, Minhas PS, Fryer TD, Aigbirhio FI, Clark JC, Smielewski P, Chatfield DA, Donovan T, Pickard JD, Menon DK. Cerebrovascular pressure reactivity is related to global cerebral oxygen metabolism after head injury. J Neurol Neurosurg Psychiatry 2003; 74:765-70. [PMID: 12754348 PMCID: PMC1738479 DOI: 10.1136/jnnp.74.6.765] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND After head injury, impaired cerebrovascular autoregulation has been associated with abnormally high or low cerebral blood flow. The physiological relevance of cerebral blood flow levels is difficult to assess in these patients, whose cerebral metabolic rate for oxygen (CMRO(2)) is known to be abnormal. Investigation of these relations requires quantitative measures of cerebral blood flow and CMRO(2), to allow assessment of oxygen supply and demand relations. OBJECTIVES To investigate the relation between dysautoregulation and global cerebral oxygen metabolism following head injury. METHODS Using positron emission tomography, global cerebral blood flow, CMRO(2), and oxygen extraction fraction were determined in 22 patients who were investigated in 26 examinations on days 1 to 11 (mean (SD), 3.5 (2.3)) after head injury. Cerebrovascular pressure reactivity was assessed using a pressure reactivity index, calculated as the moving linear correlation coefficient between mean arterial blood pressure and intracranial pressure. Outcome was assessed six months after injury using the Glasgow outcome scale. RESULTS Low CMRO(2) was associated with disturbed pressure reactivity (inverse function, R(2) = 0.21, p = 0.018) and there was a correlation between disturbed pressure reactivity and oxygen extraction fraction (quadratic function, R(2) = 0.55, p = 0.0001). There was no significant relation between pressure reactivity and cerebral blood flow. An unfavourable outcome was associated with disturbed pressure reactivity. There was no significant relation between outcome and CMRO(2) or oxygen extraction fraction. CONCLUSIONS There is a close relation between dysautoregulation and abnormal cerebral metabolism but not blood flow. Further studies are needed to determine whether metabolic dysfunction is a result of or a cause of disturbed pressure reactivity, and to establish if there is a relation between cerebral oxygen metabolism and outcome.
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Affiliation(s)
- L A Steiner
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
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