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Xu S, Chang JC, Chow CC, Brennan KC, Huang H. A mathematical model for persistent post-CSD vasoconstriction. PLoS Comput Biol 2020; 16:e1007996. [PMID: 32667909 PMCID: PMC7416967 DOI: 10.1371/journal.pcbi.1007996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 08/10/2020] [Accepted: 05/28/2020] [Indexed: 11/18/2022] Open
Abstract
Cortical spreading depression (CSD) is the propagation of a relatively slow wave in cortical brain tissue that is linked to a number of pathological conditions such as stroke and migraine. Most of the existing literature investigates the dynamics of short term phenomena such as the depolarization and repolarization of membrane potentials or large ion shifts. Here, we focus on the clinically-relevant hour-long state of neurovascular malfunction in the wake of CSDs. This dysfunctional state involves widespread vasoconstriction and a general disruption of neurovascular coupling. We demonstrate, using a mathematical model, that dissolution of calcium that has aggregated within the mitochondria of vascular smooth muscle cells can drive an hour-long disruption. We model the rate of calcium clearance as well as the dynamical implications on overall blood flow. Based on reaction stoichiometry, we quantify a possible impact of calcium phosphate dissolution on the maintenance of F0F1-ATP synthase activity.
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Affiliation(s)
- Shixin Xu
- Duke Kunshan University, 8 Duke Ave., Suzhou, China
- Department of Mathematics and Statistics, York University, Toronto, Ontario, Canada
- Centre for Quantitative Analysis and Modeling (CQAM), The Fields Institute for Research in Mathematical Sciences, 222 College Street, Toronto, Ontario, Canada
| | - Joshua C. Chang
- Laboratory of Biological Modeling, NIDDK, National Institutes of Health, Bethesda Maryland, United States of America
- Epidemiology and Biostatistics Section, Rehabilitation Medicine Department, The National Institutes of Health, Bethesda Maryland, United States of America
- mederrata, Columbus Ohio, United States of America
| | - Carson C. Chow
- Laboratory of Biological Modeling, NIDDK, National Institutes of Health, Bethesda Maryland, United States of America
| | - KC Brennan
- Department of Neurology, University of Utah, Salt Lake City, Utah, United States of America
| | - Huaxiong Huang
- Department of Mathematics and Statistics, York University, Toronto, Ontario, Canada
- Centre for Quantitative Analysis and Modeling (CQAM), The Fields Institute for Research in Mathematical Sciences, 222 College Street, Toronto, Ontario, Canada
- Research Center for Mathematics, Advanced Institute of Natural Sciences, Beijing Normal University (Zhuhai), Guangdong, China
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2
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Flavin Adenine Dinucleotide Fluorescence as an Early Marker of Mitochondrial Impairment During Brain Hypoxia. Int J Mol Sci 2020; 21:ijms21113977. [PMID: 32492921 PMCID: PMC7312830 DOI: 10.3390/ijms21113977] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/28/2020] [Accepted: 05/30/2020] [Indexed: 12/31/2022] Open
Abstract
Multimodal continuous bedside monitoring is increasingly recognized as a promising option for early treatment stratification in patients at risk for ischemia during neurocritical care. Modalities used at present are, for example, oxygen availability and subdural electrocorticography. The assessment of mitochondrial function could be an interesting complement to these modalities. For instance, flavin adenine dinucleotide (FAD) fluorescence permits direct insight into the mitochondrial redox state. Therefore, we explored the possibility of using FAD fluorometry to monitor consequences of hypoxia in brain tissue in vitro and in vivo. By combining experimental results with computational modeling, we identified the potential source responsible for the fluorescence signal and gained insight into the hypoxia-associated metabolic changes in neuronal energy metabolism. In vitro, hypoxia was characterized by a reductive shift of FAD, impairment of synaptic transmission and increasing interstitial potassium [K+]o. Computer simulations predicted FAD changes to originate from the citric acid cycle enzyme α-ketoglutarate dehydrogenase and pyruvate dehydrogenase. In vivo, the FAD signal during early hypoxia displayed a reductive shift followed by a short oxidation associated with terminal spreading depolarization. In silico, initial tissue hypoxia followed by a transient re-oxygenation phase due to glucose depletion might explain FAD dynamics in vivo. Our work suggests that FAD fluorescence could be readily used to monitor mitochondrial function during hypoxia and represents a potential diagnostic tool to differentiate underlying metabolic processes for complementation of multimodal brain monitoring.
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Pacheco JM, Hines-Lanham A, Stratton C, Mehos CJ, McCurdy KE, Pinkowski NJ, Zhang H, Shuttleworth CW, Morton RA. Spreading Depolarizations Occur in Mild Traumatic Brain Injuries and Are Associated with Postinjury Behavior. eNeuro 2019; 6:ENEURO.0070-19.2019. [PMID: 31748237 PMCID: PMC6893232 DOI: 10.1523/eneuro.0070-19.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 11/06/2019] [Accepted: 11/11/2019] [Indexed: 01/20/2023] Open
Abstract
Millions of people suffer mild traumatic brain injuries (mTBIs) every year, and there is growing evidence that repeated injuries can result in long-term pathology. The acute symptoms of these injuries may or may not include the loss of consciousness but do include disorientation, confusion, and/or the inability to concentrate. Most of these acute symptoms spontaneously resolve within a few hours or days. However, the underlying physiological and cellular mechanisms remain unclear. Spreading depolarizations (SDs) are known to occur in rodents and humans following moderate and severe TBIs, and SDs have long been hypothesized to occur in more mild injuries. Using a closed skull impact model, we investigated the presence of SDs immediately following a mTBI. Animals remained motionless for multiple minutes following an impact and once recovered had fewer episodes of movement. We recorded the defining electrophysiological properties of SDs, including the large extracellular field potential shifts and suppression of high-frequency cortical activity. Impact-induced SDs were also associated with a propagating wave of reduced cerebral blood flow (CBF). In the wake of the SD, there was a prolonged period of reduced CBF that recovered in approximately 90 min. Similar to SDs in more severe injuries, the impact-induced SDs could be blocked with ketamine. Interestingly, impacts at a slower velocity did not produce the prolonged immobility and did not initiate SDs. Our data suggest that SDs play a significant role in mTBIs and SDs may contribute to the acute symptoms of mTBIs.
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Affiliation(s)
- Johann M Pacheco
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Ashlyn Hines-Lanham
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Claire Stratton
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Carissa J Mehos
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Kathryn E McCurdy
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Natalie J Pinkowski
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Haikun Zhang
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - C William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
| | - Russell A Morton
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131
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4
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Toglia P, Ullah G. Mitochondrial dysfunction and role in spreading depolarization and seizure. J Comput Neurosci 2019; 47:91-108. [PMID: 31506806 DOI: 10.1007/s10827-019-00724-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 03/12/2019] [Accepted: 07/26/2019] [Indexed: 11/24/2022]
Abstract
The effect of pathological phenomena such as epileptic seizures and spreading depolarization (SD) on mitochondria and the potential feedback of mitochondrial dysfunction into the dynamics of those phenomena are complex and difficult to study experimentally due to the simultaneous changes in many variables governing neuronal behavior. By combining a model that accounts for a wide range of neuronal behaviors including seizures, normoxic SD, and hypoxic SD (HSD), together with a detailed model of mitochondrial function and intracellular Ca2+ dynamics, we investigate mitochondrial dysfunction and its potential role in recovery of the neuron from seizures, HSD, and SD. Our results demonstrate that HSD leads to the collapse of mitochondrial membrane potential and cellular ATP levels that recover only when normal oxygen supply is restored. Mitochondrial organic phosphate and pH gradients determine the strength of the depolarization block during HSD and SD, how quickly the cell enters the depolarization block when the oxygen supply is disrupted or potassium in the bath solution is raised beyond the physiological value, and how fast the cell recovers from SD and HSD when normal potassium concentration and oxygen supply are restored. Although not as dramatic as phosphate and pH gradients, mitochondrial Ca2+ uptake has a similar effect on neuronal behavior during these conditions.
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Affiliation(s)
- Patrick Toglia
- Department of Physics, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA
| | - Ghanim Ullah
- Department of Physics, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA.
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5
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Harris SS, Boorman LW, Das D, Kennerley AJ, Sharp PS, Martin C, Redgrave P, Schwartz TH, Berwick J. Physiological and Pathological Brain Activation in the Anesthetized Rat Produces Hemodynamic-Dependent Cortical Temperature Increases That Can Confound the BOLD fMRI Signal. Front Neurosci 2018; 12:550. [PMID: 30154690 PMCID: PMC6102348 DOI: 10.3389/fnins.2018.00550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 07/20/2018] [Indexed: 11/24/2022] Open
Abstract
Anesthetized rodent models are ubiquitous in pre-clinical neuroimaging studies. However, because the associated cerebral morphology and experimental methodology results in a profound negative brain-core temperature differential, cerebral temperature changes during functional activation are likely to be principally driven by local inflow of fresh, core-temperature, blood. This presents a confound to the interpretation of blood-oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) data acquired from such models, since this signal is also critically temperature-dependent. Nevertheless, previous investigation on the subject is surprisingly sparse. Here, we address this issue through use of a novel multi-modal methodology in the urethane anesthetized rat. We reveal that sensory stimulation, hypercapnia and recurrent acute seizures induce significant increases in cortical temperature that are preferentially correlated to changes in total hemoglobin concentration (Hbt), relative to cerebral blood flow and oxidative metabolism. Furthermore, using a phantom-based evaluation of the effect of such temperature changes on the BOLD fMRI signal, we demonstrate a robust inverse relationship between both variables. These findings suggest that temperature increases, due to functional hyperemia, should be accounted for to ensure accurate interpretation of BOLD fMRI signals in pre-clinical neuroimaging studies.
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Affiliation(s)
- Samuel S Harris
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Luke W Boorman
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Devashish Das
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Aneurin J Kennerley
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Paul S Sharp
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Chris Martin
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Peter Redgrave
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Theodore H Schwartz
- Department of Neurological Surgery, Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Jason Berwick
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
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6
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Cerebrospinal fluid and brain extracellular fluid in severe brain trauma. HANDBOOK OF CLINICAL NEUROLOGY 2018; 146:237-258. [DOI: 10.1016/b978-0-12-804279-3.00014-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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7
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Unekawa M, Tomita Y, Masamoto K, Toriumi H, Osada T, Kanno I, Suzuki N. Dynamic diameter response of intraparenchymal penetrating arteries during cortical spreading depression and elimination of vasoreactivity to hypercapnia in anesthetized mice. J Cereb Blood Flow Metab 2017; 37:657-670. [PMID: 26935936 PMCID: PMC5381456 DOI: 10.1177/0271678x16636396] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/01/2016] [Indexed: 11/16/2022]
Abstract
Cortical spreading depression (CSD) induces marked hyperemia with a transient decrease of regional cerebral blood flow (rCBF), followed by sustained oligemia. To further understand the microcirculatory mechanisms associated with CSD, we examined the temporal changes of diameter of intraparenchymal penetrating arteries during CSD. In urethane-anesthetized mice, the diameter of single penetrating arteries at three depths was measured using two-photon microscopy during passage of repeated CSD, with continuous recordings of direct current potential and rCBF. The first CSD elicited marked constriction superimposed on the upstrokes of profound dilation throughout each depth of the penetrating artery, and the vasoreaction temporally corresponded to the change of rCBF. Second or later CSD elicited marked dilation with little or no constriction phase throughout each depth, and the vasodilation also temporally corresponded to the increase of rCBF. Furthermore, the peak dilation showed good negative correlations with basal diameter and increase of rCBF. Vasodilation induced by 5% CO2 inhalation was significantly suppressed after CSD passage at any depth as well as hyperperfusion. These results may indicate that CSD-induced rCBF changes mainly reflect the diametric changes of the intraparenchymal arteries, despite the elimination of responsiveness to hypercapnia.
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Affiliation(s)
- Miyuki Unekawa
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Yutaka Tomita
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Kazuto Masamoto
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Chofu, Japan
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Haruki Toriumi
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Takashi Osada
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Iwao Kanno
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Norihiro Suzuki
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
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8
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Ayata C, Lauritzen M. Spreading Depression, Spreading Depolarizations, and the Cerebral Vasculature. Physiol Rev 2015; 95:953-93. [PMID: 26133935 DOI: 10.1152/physrev.00027.2014] [Citation(s) in RCA: 364] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Spreading depression (SD) is a transient wave of near-complete neuronal and glial depolarization associated with massive transmembrane ionic and water shifts. It is evolutionarily conserved in the central nervous systems of a wide variety of species from locust to human. The depolarization spreads slowly at a rate of only millimeters per minute by way of grey matter contiguity, irrespective of functional or vascular divisions, and lasts up to a minute in otherwise normal tissue. As such, SD is a radically different breed of electrophysiological activity compared with everyday neural activity, such as action potentials and synaptic transmission. Seventy years after its discovery by Leão, the mechanisms of SD and its profound metabolic and hemodynamic effects are still debated. What we did learn of consequence, however, is that SD plays a central role in the pathophysiology of a number of diseases including migraine, ischemic stroke, intracranial hemorrhage, and traumatic brain injury. An intriguing overlap among them is that they are all neurovascular disorders. Therefore, the interplay between neurons and vascular elements is critical for our understanding of the impact of this homeostatic breakdown in patients. The challenges of translating experimental data into human pathophysiology notwithstanding, this review provides a detailed account of bidirectional interactions between brain parenchyma and the cerebral vasculature during SD and puts this in the context of neurovascular diseases.
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Affiliation(s)
- Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark; and Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
| | - Martin Lauritzen
- Neurovascular Research Laboratory, Department of Radiology, and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark; and Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
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9
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Bedside diagnosis of mitochondrial dysfunction after malignant middle cerebral artery infarction. Neurocrit Care 2015; 21:35-42. [PMID: 23860668 DOI: 10.1007/s12028-013-9875-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND The study explores whether the cerebral biochemical pattern in patients treated with hemicraniectomy after large middle cerebral artery infarcts reflects ongoing ischemia or non-ischemic mitochondrial dysfunction. METHODS The study includes 44 patients treated with decompressive hemicraniectomy (DCH) due to malignant middle cerebral artery infarctions. Chemical variables related to energy metabolism obtained by microdialysis were analyzed in the infarcted tissue and in the contralateral hemisphere from the time of DCH until 96 h after DCH. RESULTS Reperfusion of the infarcted tissue was documented in a previous report. Cerebral lactate/pyruvate ratio (L/P) and lactate were significantly elevated in the infarcted tissue compared to the non-infarcted hemisphere (p < 0.05). From 12 to 96 h after DCH the pyruvate level was significantly higher in the infarcted tissue than in the non-infarcted hemisphere (p < 0.05). CONCLUSION After a prolonged period of ischemia and subsequent reperfusion, cerebral tissue shows signs of protracted mitochondrial dysfunction, characterized by a marked increase in cerebral lactate level with a normal or increased cerebral pyruvate level resulting in an increased LP-ratio. This biochemical pattern contrasts to cerebral ischemia, which is characterized by a marked decrease in cerebral pyruvate. The study supports the hypothesis that it is possible to diagnose cerebral mitochondrial dysfunction and to separate it from cerebral ischemia by microdialysis and bed-side biochemical analysis.
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10
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Unekawa M, Tomita Y, Toriumi H, Osada T, Masamoto K, Kawaguchi H, Itoh Y, Kanno I, Suzuki N. Hyperperfusion counteracted by transient rapid vasoconstriction followed by long-lasting oligemia induced by cortical spreading depression in anesthetized mice. J Cereb Blood Flow Metab 2015; 35:689-98. [PMID: 25586145 PMCID: PMC4420891 DOI: 10.1038/jcbfm.2014.250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/29/2014] [Accepted: 12/11/2014] [Indexed: 11/09/2022]
Abstract
Cortical spreading depression (CSD) involves mass depolarization of neurons and glial cells accompanied with changes in regional cerebral blood flow (rCBF) and energy metabolism. To further understand the mechanisms of CBF response, we examined the temporal diametric changes in pial arteries, pial veins, and cortical capillaries. In urethane-anesthetized mice, the diameters of these vessels were measured while simultaneously recording rCBF with a laser Doppler flowmeter. We observed a considerable increase in rCBF during depolarization in CSD induced by application of KCl, accompanied by a transient dip of rCBF with marked vasoconstriction of pial arteries, which resembled the response to pin-prick-induced CSD. Arterial constriction diminished or disappeared during the second and third passages of CSD, whereas the rCBF increase was maintained without a transient dip. Long-lasting oligemia with a decrease in the reciprocal of mean transit time of injected dye and mild constriction of pial arteries was observed after several passages of the CSD wave. These results indicate that CSD-induced rCBF changes consist of initial hyperemia with a transient dip and followed by a long-lasting oligemia, partially corresponding to the diametric changes of pial arteries, and further suggest that vessels other than pial arteries, such as intracortical vessels, are involved.
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Affiliation(s)
- Miyuki Unekawa
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Yutaka Tomita
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Haruki Toriumi
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Takashi Osada
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Kazuto Masamoto
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo, Japan
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Hiroshi Kawaguchi
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Yoshiaki Itoh
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
| | - Iwao Kanno
- Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Norihiro Suzuki
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
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11
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Stein DG, Geddes RI, Sribnick EA. Recent developments in clinical trials for the treatment of traumatic brain injury. HANDBOOK OF CLINICAL NEUROLOGY 2015; 127:433-51. [PMID: 25702233 DOI: 10.1016/b978-0-444-52892-6.00028-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The clinical understanding of traumatic brain injury (TBI) and its manifestations is beginning to change. Both clinicians and research scientists are recognizing that TBI and related disorders such as stroke are complex, systemic inflammatory and degenerative diseases that require an approach to treatment more sophisticated than targeting a single gene, receptor, or signaling pathway. It is becoming increasingly clear that TBI is a form of degenerative disorder affecting the brain and other organs, and that its manifestations can unfold days, weeks, and years after the initial damage. Until recently, and despite numerous industry- and government-sponsored clinical trials, attempts to find a safe and effective neuroprotective agent have all failed - probably because the research and development strategies have been based on an outdated early 20th century paradigm seeking a magic bullet that will affect a narrowly circumscribed target. We propose that more attention be given to the development of drugs, given alone or in combination, that are pleiotropic in their actions and that have systemic as well as central nervous system effects. We review current Phase II and Phase III trials for acute pharmacologic treatments for TBI and report on their aims, methods, status, and important associated research issues.
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Affiliation(s)
- Donald G Stein
- Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, USA.
| | - Rastafa I Geddes
- Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Eric A Sribnick
- Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, USA
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12
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Bramlett HM, Dietrich WD. Long-Term Consequences of Traumatic Brain Injury: Current Status of Potential Mechanisms of Injury and Neurological Outcomes. J Neurotrauma 2014; 32:1834-48. [PMID: 25158206 DOI: 10.1089/neu.2014.3352] [Citation(s) in RCA: 304] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Traumatic brain injury (TBI) is a significant clinical problem with few therapeutic interventions successfully translated to the clinic. Increased importance on the progressive, long-term consequences of TBI have been emphasized, both in the experimental and clinical literature. Thus, there is a need for a better understanding of the chronic consequences of TBI, with the ultimate goal of developing novel therapeutic interventions to treat the devastating consequences of brain injury. In models of mild, moderate, and severe TBI, histopathological and behavioral studies have emphasized the progressive nature of the initial traumatic insult and the involvement of multiple pathophysiological mechanisms, including sustained injury cascades leading to prolonged motor and cognitive deficits. Recently, the increased incidence in age-dependent neurodegenerative diseases in this patient population has also been emphasized. Pathomechanisms felt to be active in the acute and long-term consequences of TBI include excitotoxicity, apoptosis, inflammatory events, seizures, demyelination, white matter pathology, as well as decreased neurogenesis. The current article will review many of these pathophysiological mechanisms that may be important targets for limiting the chronic consequences of TBI.
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Affiliation(s)
- Helen M Bramlett
- The Miami Project to Cure Paralysis/Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida
| | - W Dalton Dietrich
- The Miami Project to Cure Paralysis/Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida
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13
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Turner DA. Neurovascular regulation is critical for metabolic recovery from spreading depression. ACTA ACUST UNITED AC 2014; 137:2877-8. [PMID: 25344082 DOI: 10.1093/brain/awu263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Dennis A Turner
- Professor, Neurosurgery and Neurobiology, Duke University Medical Centre, Durham NC 27710, USA E-mail:
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14
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Diaz-Arrastia R, Kochanek PM, Bergold P, Kenney K, Marx CE, Grimes CJB, Loh LTCY, Adam LTCGE, Oskvig D, Curley KC, Salzer W. Pharmacotherapy of traumatic brain injury: state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup. J Neurotrauma 2014; 31:135-58. [PMID: 23968241 DOI: 10.1089/neu.2013.3019] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Despite substantial investments by government, philanthropic, and commercial sources over the past several decades, traumatic brain injury (TBI) remains an unmet medical need and a major source of disability and mortality in both developed and developing societies. The U.S. Department of Defense neurotrauma research portfolio contains more than 500 research projects funded at more than $700 million and is aimed at developing interventions that mitigate the effects of trauma to the nervous system and lead to improved quality of life outcomes. A key area of this portfolio focuses on the need for effective pharmacological approaches for treating patients with TBI and its associated symptoms. The Neurotrauma Pharmacology Workgroup was established by the U.S. Army Medical Research and Materiel Command (USAMRMC) with the overarching goal of providing a strategic research plan for developing pharmacological treatments that improve clinical outcomes after TBI. To inform this plan, the Workgroup (a) assessed the current state of the science and ongoing research and (b) identified research gaps to inform future development of research priorities for the neurotrauma research portfolio. The Workgroup identified the six most critical research priority areas in the field of pharmacological treatment for persons with TBI. The priority areas represent parallel efforts needed to advance clinical care; each requires independent effort and sufficient investment. These priority areas will help the USAMRMC and other funding agencies strategically guide their research portfolios to ensure the development of effective pharmacological approaches for treating patients with TBI.
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Affiliation(s)
- Ramon Diaz-Arrastia
- 1 Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, Maryland
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15
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Clark D, Institoris Á, Kozák G, Bere Z, Tuor U, Farkas E, Bari F. Impact of aging on spreading depolarizations induced by focal brain ischemia in rats. Neurobiol Aging 2014; 35:2803-2811. [PMID: 25044075 DOI: 10.1016/j.neurobiolaging.2014.06.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/27/2014] [Accepted: 06/10/2014] [Indexed: 11/25/2022]
Abstract
Spreading depolarization (SD) contributes to the ischemic damage of the penumbra. Although age is the largest predictor of stroke, no studies have examined age dependence of SD appearance. We characterized the electrophysiological and hemodynamic changes in young (6 weeks old, n = 7), middle-aged (9 months old, n = 6), and old (2 years old, n = 7) male Wistar rats during 30 minutes of middle cerebral artery occlusion (MCAO), utilizing multimodal imaging through a closed cranial window over the ischemic cortex: membrane potential changes (with a voltage-sensitive dye), cerebral blood volume (green light reflectance), and cerebral blood flow (CBF, laser-speckle imaging) were observed. The initial CBF drop was similar in all groups, with a significant further reduction during ischemia in old rats (p < 0.01). Age reduced the total number of SDs (p < 0.05) but increased the size of ischemic area displaying prolonged SD (p < 0.01). The growth of area undergoing prolonged SDs positively correlated with the growth of ischemic core area (p < 0.01) during MCAO. Prolonged SDs and associated hypoperfusion likely compromise cortical tissue exposed to even a short focal ischemia in aged rats.
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Affiliation(s)
- Darren Clark
- Department of Medical Physics and Informatics, School of Medicine, University of Szeged, Szeged, Hungary; Department of Clinical Neurosciences, University of Calgary, Calgary, Canada.
| | - Ádám Institoris
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Gábor Kozák
- Department of Medical Physics and Informatics, School of Medicine, University of Szeged, Szeged, Hungary
| | - Zsófia Bere
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Ursula Tuor
- Department of Clinical Neurosciences, University of Calgary, Calgary, Canada; Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada
| | - Eszter Farkas
- Department of Medical Physics and Informatics, School of Medicine, University of Szeged, Szeged, Hungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, School of Medicine, University of Szeged, Szeged, Hungary
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Miwa Y, Hosaka M, Ohtsuka K, Sato M, Takahashi R, Wakabayashi K, Odai T, Yajima N, Kasama T. Depression is improved when low-dose tacrolimus is given to rheumatoid arthritis patients showing an inadequate response to biologic agents. Mod Rheumatol 2014. [DOI: 10.3109/s10165-012-0765-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Affiliation(s)
- Cenk Ayata
- Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA.
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18
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Koide M, Sukhotinsky I, Ayata C, Wellman GC. Subarachnoid hemorrhage, spreading depolarizations and impaired neurovascular coupling. Stroke Res Treat 2013; 2013:819340. [PMID: 23577279 PMCID: PMC3610342 DOI: 10.1155/2013/819340] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 02/08/2013] [Indexed: 11/17/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) has devastating consequences on brain function including profound effects on communication between neurons and the vasculature leading to cerebral ischemia. Physiologically, neurovascular coupling represents a focal increase in cerebral blood flow to meet increased metabolic demand of neurons within active regions of the brain. Neurovascular coupling is an ongoing process involving coordinated activity of the neurovascular unit-neurons, astrocytes, and parenchymal arterioles. Neuronal activity can also influence cerebral blood flow on a larger scale. Spreading depolarizations (SD) are self-propagating waves of neuronal depolarization and are observed during migraine, traumatic brain injury, and stroke. Typically, SD is associated with increased cerebral blood flow. Emerging evidence indicates that SAH causes inversion of neurovascular communication on both the local and global level. In contrast to other events causing SD, SAH-induced SD decreases rather than increases cerebral blood flow. Further, at the level of the neurovascular unit, SAH causes an inversion of neurovascular coupling from vasodilation to vasoconstriction. Global ischemia can also adversely affect the neurovascular response. Here, we summarize current knowledge regarding the impact of SAH and global ischemia on neurovascular communication. A mechanistic understanding of these events should provide novel strategies to treat these neurovascular disorders.
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Affiliation(s)
- Masayo Koide
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, VT 05405-0068, USA
| | - Inna Sukhotinsky
- Neurovascular Research Laboratory, Department of Radiology, Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02115, USA
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 52990, Israel
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - George C. Wellman
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, VT 05405-0068, USA
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Hoffmann U, Ayata C. Neurovascular coupling during spreading depolarizations. ACTA NEUROCHIRURGICA. SUPPLEMENT 2012; 115:161-5. [PMID: 22890663 DOI: 10.1007/978-3-7091-1192-5_31] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Injury depolarizations akin to spreading depression of Leão are important in the progression of tissue damage in ischemic stroke, intracranial hemorrhage, and trauma. Much of the research on injury depolarizations has been focused on their origins, electrophysiological mechanisms, and metabolic impact. Recent studies showed that injury depolarizations cause vasoconstriction and diminish perfusion, which radically differs from the predominantly hyperemic response to spreading depression in otherwise-normal brain tissue. This adverse hemodynamic effect exacerbates metabolic supply-demand mismatch and worsens the tissue outcome. Although the mechanisms transforming the hemodynamic response from vasodilation into vasoconstriction are unclear, recent data suggest a role for elevated extracellular K(+) and reduced intravascular perfusion pressure, among other factors. Clues from physiological and pharmacological studies in normal or injured brain in different species suggest that the intense pandepolarization evokes multiple opposing vasomotor mechanisms with variable magnitudes and timing, providing a conceptual framework to dissect the complex neurovascular coupling in brain injury.
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Affiliation(s)
- Ulrike Hoffmann
- Klinik für Anaesthesiologie Technische, Universität MünchenKlinikum rechts der Isar, München, Germany
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20
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Depression is improved when low-dose tacrolimus is given to rheumatoid arthritis patients showing an inadequate response to biologic agents. Mod Rheumatol 2012; 23:920-4. [PMID: 22990336 DOI: 10.1007/s10165-012-0765-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/29/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE Depression in rheumatoid arthritis (RA) patients is more severe than in healthy people. Herein, we report improved depression in RA patients using biologic agents. We examined whether depression was improved by tacrolimus combination therapy when biologic agents were ineffective. METHOD The study included 13 RA patients who used biologic agents. The following methods were used before the initiation of tacrolimus combination therapy and at 14 and 30 weeks after treatment initiation: the Zung self-rating depression scale (SDS) to evaluate depression state, disease activity score 28/erythrocyte sedimentation rate (DAS28), tender joint counts, swollen joint counts, a patient global assessment to evaluate RA disease activity, and the modified health assessment questionnaire (mHAQ) to evaluate quality of life. RESULTS The SDS scores before the initiation of tacrolimus combination therapy and at 14 and 30 weeks after treatment initiation were 45.2 ± 10.6, 44.8 ± 12.8, and 41.6 ± 11.2 (p = 0.047), respectively, indicating significant improvement. The DAS28 was 5.0 ± 1.3 prior to treatment, 3.8 ± 1.3 at 14 weeks, and 3.5 ± 0.9 at 30 weeks, demonstrating significant improvement at both 14 and 30 weeks (p < 0.001). The mHAQ score changed from 0.60 ± 0.45 at baseline to 0.54 ± 0.52 and 0.38 ± 0.43 at 14 and 30 weeks, respectively. The mHAQ score was significantly lower at 30 weeks when compared to baseline (p = 0.013). CONCLUSION Tacrolimus combination therapy does not directly improve depression in RA patients, but it is possible that the observed improvement in depression accompanies the improvement in the secondary failure of RA.
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Gill RS, Lee TF, Liu JQ, Chaudhary H, Brocks DR, Bigam DL, Cheung PY. Cyclosporine treatment reduces oxygen free radical generation and oxidative stress in the brain of hypoxia-reoxygenated newborn piglets. PLoS One 2012; 7:e40471. [PMID: 22792343 PMCID: PMC3392221 DOI: 10.1371/journal.pone.0040471] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 06/08/2012] [Indexed: 11/05/2022] Open
Abstract
Oxygen free radicals have been implicated in the pathogenesis of hypoxic-ischemic encephalopathy. It has previously been shown in traumatic brain injury animal models that treatment with cyclosporine reduces brain injury. However, the potential neuroprotective effect of cyclosporine in asphyxiated neonates has yet to be fully studied. Using an acute newborn swine model of hypoxia-reoxygenation, we evaluated the effects of cyclosporine on the brain, focusing on hydrogen peroxide (H(2)O(2)) production and markers of oxidative stress. Piglets (1-4 d, 1.4-2.5 kg) were block-randomized into three hypoxia-reoxygenation experimental groups (2 h hypoxia followed by 4 h reoxygenation) (n = 8/group). At 5 min after reoxygenation, piglets were given either i.v. saline (placebo, controls) or cyclosporine (2.5 or 10 mg/kg i.v. bolus) in a blinded-randomized fashion. An additional sham-operated group (n = 4) underwent no hypoxia-reoxygenation. Systemic hemodynamics, carotid arterial blood flow (transit-time ultrasonic probe), cerebral cortical H(2)O(2) production (electrochemical sensor), cerebral tissue glutathione (ELISA) and cytosolic cytochrome-c (western blot) levels were examined. Hypoxic piglets had cardiogenic shock (cardiac output 40-48% of baseline), hypotension (mean arterial pressure 27-31 mmHg) and acidosis (pH 7.04) at the end of 2 h of hypoxia. Post-resuscitation cyclosporine treatment, particularly the higher dose (10 mg/kg), significantly attenuated the increase in cortical H(2)O(2) concentration during reoxygenation, and was associated with lower cerebral oxidized glutathione levels. Furthermore, cyclosporine treatment significantly attenuated the increase in cortical cytochrome-c and lactate levels. Carotid blood arterial flow was similar among groups during reoxygenation. Conclusively, post-resuscitation administration of cyclosporine significantly attenuates H(2)O(2) production and minimizes oxidative stress in newborn piglets following hypoxia-reoxygenation.
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Affiliation(s)
- Richdeep S. Gill
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Tze-Fun Lee
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Jiang-Qin Liu
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Hetal Chaudhary
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Dion R. Brocks
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - David L. Bigam
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Po-Yin Cheung
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
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