1
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Planas AM. Role of microglia in stroke. Glia 2024; 72:1016-1053. [PMID: 38173414 DOI: 10.1002/glia.24501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
Microglia play key roles in the post-ischemic inflammatory response and damaged tissue removal reacting rapidly to the disturbances caused by ischemia and working to restore the lost homeostasis. However, the modified environment, encompassing ionic imbalances, disruption of crucial neuron-microglia interactions, spreading depolarization, and generation of danger signals from necrotic neurons, induce morphological and phenotypic shifts in microglia. This leads them to adopt a proinflammatory profile and heighten their phagocytic activity. From day three post-ischemia, macrophages infiltrate the necrotic core while microglia amass at the periphery. Further, inflammation prompts a metabolic shift favoring glycolysis, the pentose-phosphate shunt, and lipid synthesis. These shifts, combined with phagocytic lipid intake, drive lipid droplet biogenesis, fuel anabolism, and enable microglia proliferation. Proliferating microglia release trophic factors contributing to protection and repair. However, some microglia accumulate lipids persistently and transform into dysfunctional and potentially harmful foam cells. Studies also showed microglia that either display impaired apoptotic cell clearance, or eliminate synapses, viable neurons, or endothelial cells. Yet, it will be essential to elucidate the viability of engulfed cells, the features of the local environment, the extent of tissue damage, and the temporal sequence. Ischemia provides a rich variety of region- and injury-dependent stimuli for microglia, evolving with time and generating distinct microglia phenotypes including those exhibiting proinflammatory or dysfunctional traits and others showing pro-repair features. Accurate profiling of microglia phenotypes, alongside with a more precise understanding of the associated post-ischemic tissue conditions, is a necessary step to serve as the potential foundation for focused interventions in human stroke.
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Affiliation(s)
- Anna M Planas
- Cerebrovascular Research Laboratory, Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
- Cerebrovascular Diseases, Area of Clinical and Experimental Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Hospital Clínic, Barcelona, Spain
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2
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Álvarez-Merz I, Fomitcheva IV, Sword J, Hernández-Guijo JM, Solís JM, Kirov SA. Novel mechanism of hypoxic neuronal injury mediated by non-excitatory amino acids and astroglial swelling. Glia 2022; 70:2108-2130. [PMID: 35802030 PMCID: PMC9474671 DOI: 10.1002/glia.24241] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/14/2022] [Accepted: 06/24/2022] [Indexed: 11/08/2022]
Abstract
In ischemic stroke and post-traumatic brain injury (TBI), blood-brain barrier disruption leads to leaking plasma amino acids (AA) into cerebral parenchyma. Bleeding in hemorrhagic stroke and TBI also release plasma AA. Although excitotoxic AA were extensively studied, little is known about non-excitatory AA during hypoxic injury. Hypoxia-induced synaptic depression in hippocampal slices becomes irreversible with non-excitatory AA, alongside their intracellular accumulation and increased tissue electrical resistance. Four non-excitatory AA (l-alanine, glycine, l-glutamine, l-serine: AGQS) at plasmatic concentrations were applied to slices from mice expressing EGFP in pyramidal neurons or astrocytes during normoxia or hypoxia. Two-photon imaging, light transmittance (LT) changes, and electrophysiological field recordings followed by electron microscopy in hippocampal CA1 st. radiatum were used to monitor synaptic function concurrently with cellular swelling and injury. During normoxia, AGQS-induced increase in LT was due to astroglial but not neuronal swelling. LT raise during hypoxia and AGQS manifested astroglial and neuronal swelling accompanied by a permanent loss of synaptic transmission and irreversible dendritic beading, signifying acute damage. Neuronal injury was not triggered by spreading depolarization which did not occur in our experiments. Hypoxia without AGQS did not cause cell swelling, leaving dendrites intact. Inhibition of NMDA receptors prevented neuronal damage and irreversible loss of synaptic function. Deleterious effects of AGQS during hypoxia were prevented by alanine-serine-cysteine transporters (ASCT2) and volume-regulated anion channels (VRAC) blockers. Our findings suggest that astroglial swelling induced by accumulation of non-excitatory AA and release of excitotoxins through antiporters and VRAC may exacerbate the hypoxia-induced neuronal injury.
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Affiliation(s)
- Iris Álvarez-Merz
- Dept. de Farmacología y Terapéutica, ITH, Facultad de Medicina, Universidad Autónoma de Madrid, IRYCIS, 28029 Madrid, Spain
- Servicio de Neurobiología-Investigación, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain
- Dept. of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia 30912, USA
| | - Ioulia V. Fomitcheva
- Dept. of Neurosurgery, Medical College of Georgia at Augusta University, Augusta, Georgia 30912, USA
| | - Jeremy Sword
- Dept. of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia 30912, USA
| | - Jesús M. Hernández-Guijo
- Dept. de Farmacología y Terapéutica, ITH, Facultad de Medicina, Universidad Autónoma de Madrid, IRYCIS, 28029 Madrid, Spain
| | - José M. Solís
- Servicio de Neurobiología-Investigación, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain
| | - Sergei A. Kirov
- Dept. of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia 30912, USA
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3
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Li J, Chen Z, Chen J, Yu Y. The beneficial roles of apelin-13/APJ system in cerebral ischemia: Pathogenesis and therapeutic strategies. Front Pharmacol 2022; 13:903151. [PMID: 36034795 PMCID: PMC9399844 DOI: 10.3389/fphar.2022.903151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 07/18/2022] [Indexed: 12/04/2022] Open
Abstract
The incidence of cerebral ischemia has increased in the past decades, and the high fatality and disability rates seriously affect human health. Apelin is a bioactive peptide and the ligand of the G protein-coupled receptor APJ. Both are ubiquitously expressed in the peripheral and central nervous systems, and regulate various physiological and pathological process in the cardiovascular, nervous and endocrine systems. Apelin-13 is one of the subtypes of apelin, and the apelin-13/APJ signaling pathway protects against cerebral ischemia by promoting angiogenesis, inhibiting excitotoxicity and stabilizing atherosclerotic plaques. In this review, we have discussed the role of apelin-13 in the regulation of cerebral ischemia and the underlying mechanisms, along with the therapeutic potential of the apelin-13/APJ signaling pathway in cerebral ischemia.
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Affiliation(s)
- Jiabin Li
- Department of Pharmacy, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Zhang Chen
- Department of Tuina, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Jingyu Chen
- Department of Critical Care Medicine, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
- *Correspondence: Jingyu Chen, ; Yue Yu,
| | - Yue Yu
- Department of Critical Care Medicine, Zhejiang Provincial People’s Hospital, People’s Hospital of Hangzhou Medical College, Hangzhou, China
- *Correspondence: Jingyu Chen, ; Yue Yu,
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4
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Andrew RD, Farkas E, Hartings JA, Brennan KC, Herreras O, Müller M, Kirov SA, Ayata C, Ollen-Bittle N, Reiffurth C, Revah O, Robertson RM, Dawson-Scully KD, Ullah G, Dreier JP. Questioning Glutamate Excitotoxicity in Acute Brain Damage: The Importance of Spreading Depolarization. Neurocrit Care 2022; 37:11-30. [PMID: 35194729 PMCID: PMC9259542 DOI: 10.1007/s12028-021-01429-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/20/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Within 2 min of severe ischemia, spreading depolarization (SD) propagates like a wave through compromised gray matter of the higher brain. More SDs arise over hours in adjacent tissue, expanding the neuronal damage. This period represents a therapeutic window to inhibit SD and so reduce impending tissue injury. Yet most neuroscientists assume that the course of early brain injury can be explained by glutamate excitotoxicity, the concept that immediate glutamate release promotes early and downstream brain injury. There are many problems with glutamate release being the unseen culprit, the most practical being that the concept has yielded zero therapeutics over the past 30 years. But the basic science is also flawed, arising from dubious foundational observations beginning in the 1950s METHODS: Literature pertaining to excitotoxicity and to SD over the past 60 years is critiqued. RESULTS Excitotoxicity theory centers on the immediate and excessive release of glutamate with resulting neuronal hyperexcitation. This instigates poststroke cascades with subsequent secondary neuronal injury. By contrast, SD theory argues that although SD evokes some brief glutamate release, acute neuronal damage and the subsequent cascade of injury to neurons are elicited by the metabolic stress of SD, not by excessive glutamate release. The challenge we present here is to find new clinical targets based on more informed basic science. This is motivated by the continuing failure by neuroscientists and by industry to develop drugs that can reduce brain injury following ischemic stroke, traumatic brain injury, or sudden cardiac arrest. One important step is to recognize that SD plays a central role in promoting early neuronal damage. We argue that uncovering the molecular biology of SD initiation and propagation is essential because ischemic neurons are usually not acutely injured unless SD propagates through them. The role of glutamate excitotoxicity theory and how it has shaped SD research is then addressed, followed by a critique of its fading relevance to the study of brain injury. CONCLUSIONS Spreading depolarizations better account for the acute neuronal injury arising from brain ischemia than does the early and excessive release of glutamate.
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Affiliation(s)
| | - Eszter Farkas
- Hungarian Centre of Excellence for Molecular Medicine-University of Szeged, Cerebral Blood Flow and Metabolism Research Group, Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | | | | | | | | | | | - Cenk Ayata
- Harvard Medical School, Harvard University, Boston, MA USA
| | | | - Clemens Reiffurth
- Center for Stroke Research Berlin, Berlin, Germany
- Department of Experimental Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Omer Revah
- School of Medicine, Stanford University, Stanford, CA USA
| | | | | | | | - Jens P. Dreier
- Center for Stroke Research Berlin, Berlin, Germany
- Department of Experimental Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany
- Department of Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany
- Department of Neurology, Corporate Member of Freie Universität Berlin, Berlin, Germany
- Department of Neurology, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Berlin Institute of Health, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- Einstein Center for Neurosciences Berlin, Berlin, Germany
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5
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Pan X, Tao S, Tong N. Potential Therapeutic Targeting Neurotransmitter Receptors in Diabetes. Front Endocrinol (Lausanne) 2022; 13:884549. [PMID: 35669692 PMCID: PMC9163348 DOI: 10.3389/fendo.2022.884549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 04/19/2022] [Indexed: 12/04/2022] Open
Abstract
Neurotransmitters are signaling molecules secreted by neurons to coordinate communication and proper function among different sections in the central neural system (CNS) by binding with different receptors. Some neurotransmitters as well as their receptors are found in pancreatic islets and are involved in the regulation of glucose homeostasis. Neurotransmitters can act with their receptors in pancreatic islets to stimulate or inhibit the secretion of insulin (β cell), glucagon (α cell) or somatostatin (δ cell). Neurotransmitter receptors are either G-protein coupled receptors or ligand-gated channels, their effects on blood glucose are mainly decided by the number and location of them in islets. Dysfunction of neurotransmitters receptors in islets is involved in the development of β cell dysfunction and type 2 diabetes (T2D).Therapies targeting different transmitter systems have great potential in the prevention and treatment of T2D and other metabolic diseases.
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Affiliation(s)
- Xiaohui Pan
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Diabetes and Islet Transplantation, Center for Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
| | - Shibing Tao
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Department of Endocrinology, Ziyang First People’s Hospital, Ziyang, China
| | - Nanwei Tong
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Diabetes and Islet Transplantation, Center for Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Nanwei Tong,
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6
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Chen L, Hu J, Mu J, Li C, Wu GY, He C, Xie Y, Ye JN. Specific stimulation of PV + neurons at early stage ameliorates prefrontal ischemia-induced spatial working memory impairment. Behav Brain Res 2021; 414:113511. [PMID: 34358569 DOI: 10.1016/j.bbr.2021.113511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 11/16/2022]
Abstract
Prefrontal ischemia can cause impairments in learning and memory, executive functions and cognitive flexibility. However, the related cellular mechanisms at the early stage are still elusive. The present study used ischemic stroke in medial prefrontal cortex and systemically investigated the electrophysiological changes of the parvalbumin (PV+) interneurons 12 h post ischemia. We found that Ih and the related voltage sags in PV+ interneurons are downregulated post ischemia, which correlates with hyperpolarization of the membrane potentials and increased input resistance in these interneurons. Consistent with the suppression of Ih, postischemic PV+ interneurons exhibited a reduction in excitability and exerted a less inhibitory control over the neighboring pyramidal excitatory neurons. Moreover, we found that specifically chemogenetic activation of PV+ neurons at early stage ameliorated prefrontal ischemia-induced spatial working memory dysfunction in T-maze without effects on the locomotor coordination and balance. In contrast, suppression of PV+ neurons by blockade of Ih leaded to further aggravate the damage of spatial memory. These findings indicate that dysfunctional Ih in the PV+ neuron postischemia induces the imbalance of excitation and inhibition, which might represent a novel mechanism underlying the prefrontal ischemia-induced cognitive impairment.
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Affiliation(s)
- Lin Chen
- Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, PR China
| | - Jun Hu
- Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing 400038, PR China
| | - Jiankun Mu
- The Affiliated Rehabilitation Hospital of Chongqing Medical University, Chongqing 400036, PR China
| | - Chao Li
- Department of Neurology, The General Hospital of Western Theater Command, No.270 Rongdu Avenue, Jinniu District, Chengdu 610083, Sichuan Province, PR China
| | - Guang-Yan Wu
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, PR China
| | - Chao He
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400037, PR China
| | - Youhong Xie
- The Affiliated Rehabilitation Hospital of Chongqing Medical University, Chongqing 400036, PR China
| | - Jian-Ning Ye
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
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7
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Muhire G, Iulita MF, Vallerand D, Youwakim J, Gratuze M, Petry FR, Planel E, Ferland G, Girouard H. Arterial Stiffness Due to Carotid Calcification Disrupts Cerebral Blood Flow Regulation and Leads to Cognitive Deficits. J Am Heart Assoc 2020; 8:e011630. [PMID: 31057061 PMCID: PMC6512142 DOI: 10.1161/jaha.118.011630] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Arterial stiffness is associated with cognitive decline and dementia; however, the precise mechanisms by which it affects the brain remain unclear. Methods and Results Using a mouse model based on carotid calcification this study characterized mechanisms that could contribute to brain degeneration due to arterial stiffness. At 2 weeks postcalcification, carotid stiffness attenuated resting cerebral blood flow in several brain regions including the perirhinal/entorhinal cortex, hippocampus, and thalamus, determined by autoradiography (P<0.05). Carotid calcification impaired cerebral autoregulation and diminished cerebral blood flow responses to neuronal activity and to acetylcholine, examined by laser Doppler flowmetry (P<0.05, P<0.01). Carotid stiffness significantly affected spatial memory at 3 weeks (P<0.05), but not at 2 weeks, suggesting that cerebrovascular impairments precede cognitive dysfunction. In line with the endothelial deficits, carotid stiffness led to increased blood‐brain barrier permeability in the hippocampus (P<0.01). This region also exhibited reductions in vessel number containing collagen IV (P<0.01), as did the somatosensory cortex (P<0.05). No evidence of cerebral microhemorrhages was present. Carotid stiffness did not affect the production of mouse amyloid‐β (Aβ) or tau phosphorylation, although it led to a modest increase in the Aβ40/Aβ42 ratio in frontal cortex (P<0.01). Conclusions These findings suggest that carotid stiffness alters brain microcirculation and increases blood‐brain barrier permeability associated with cognitive impairments. Therefore, arterial stiffness should be considered a relevant target to protect the brain and prevent cognitive dysfunctions.
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Affiliation(s)
- Gervais Muhire
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada
| | - M Florencia Iulita
- 2 Groupe de Recherche sur le Système Nerveux Central Université de Montréal Québec Canada.,3 Département de Neurosciences Université de Montréal Québec Canada
| | - Diane Vallerand
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada
| | - Jessica Youwakim
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada
| | - Maud Gratuze
- 4 Département de Psychiatrie et Neurosciences Université Laval Québec Québec Canada
| | - Franck R Petry
- 4 Département de Psychiatrie et Neurosciences Université Laval Québec Québec Canada
| | - Emmanuel Planel
- 4 Département de Psychiatrie et Neurosciences Université Laval Québec Québec Canada.,5 Centre de Recherche du CHU de Québec Québec Canada
| | - Guylaine Ferland
- 6 Département de Nutrition Université de Montréal Québec Canada.,7 Centre de Recherche de l'Institut de Cardiologie de Montréal Montréal Québec Canada
| | - Hélène Girouard
- 1 Département de Pharmacologie et Physiologie Université de Montréal Québec Canada.,2 Groupe de Recherche sur le Système Nerveux Central Université de Montréal Québec Canada.,8 Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal Montréal Québec Canada
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8
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Buendia I, Tenti G, Michalska P, Méndez-López I, Luengo E, Satriani M, Padín-Nogueira F, López MG, Ramos MT, García AG, Menéndez JC, León R. ITH14001, a CGP37157-Nimodipine Hybrid Designed to Regulate Calcium Homeostasis and Oxidative Stress, Exerts Neuroprotection in Cerebral Ischemia. ACS Chem Neurosci 2017; 8:67-81. [PMID: 27731633 DOI: 10.1021/acschemneuro.6b00181] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
During brain ischemia, oxygen and glucose deprivation induces calcium overload, extensive oxidative stress, neuroinflammation, and, finally, massive neuronal loss. In the search of a neuroprotective compound to mitigate this neuronal loss, we have designed and synthesized a new multitarget hybrid (ITH14001) directed at the reduction of calcium overload by acting on two regulators of calcium homeostasis; the mitochondrial Na+/Ca2+ exchanger (mNCX) and L-type voltage dependent calcium channels (VDCCs). This compound is a hybrid of CGP37157 (mNCX inhibitor) and nimodipine (L-type VDCCs blocker), and its pharmacological evaluation revealed a moderate ability to selectively inhibit both targets. These activities conferred concentration-dependent neuroprotection in two models of Ca2+ overload, such as toxicity induced by high K+ in the SH-SY5Y cell line (60% protection at 30 μM) and veratridine in hippocampal slices (26% protection at 10 μM). It also showed neuroprotective effect against oxidative stress, an activity related to its nitrogen radical scavenger effect and moderate induction of the Nrf2-ARE pathway. Its Nrf2 induction capability was confirmed by the increase of the expression of the antioxidant and anti-inflammatory enzyme heme-oxygenase I (3-fold increase). In addition, the multitarget profile of ITH14001 led to anti-inflammatory properties, shown by the reduction of nitrites production induced by lipopolysaccharide in glial cultures. Finally, it showed protective effect in two acute models of cerebral ischemia in hippocampal slices, excitotoxicity induced by glutamate (31% protection at 10 μM) and oxygen and glucose deprivation (76% protection at 10 μM), reducing oxidative stress and iNOS deleterious induction. In conclusion, our hybrid derivative showed improved neuroprotective properties when compared to its parent compounds CGP37157 and nimodipine.
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Affiliation(s)
- Izaskun Buendia
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
| | - Giammarco Tenti
- Departamento
de Química Orgánica y Farmacéutica, Facultad
de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - Patrycja Michalska
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
| | - Iago Méndez-López
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
| | - Enrique Luengo
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
| | - Michele Satriani
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Departamento
de Química Orgánica y Farmacéutica, Facultad
de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - Fernando Padín-Nogueira
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
| | - Manuela G. López
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
| | - M. Teresa Ramos
- Departamento
de Química Orgánica y Farmacéutica, Facultad
de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - Antonio G. García
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
| | - J. Carlos Menéndez
- Departamento
de Química Orgánica y Farmacéutica, Facultad
de Farmacia, Universidad Complutense, 28040 Madrid, Spain
| | - Rafael León
- Instituto
Teófilo Hernando y Departamento de Farmacología y Terapéutica,
Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
- Instituto
de Investigación Sanitaria, Servicio de Farmacología
Clínica, Hospital Universitario de la Princesa, 28006 Madrid, Spain
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9
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Prochnow N. Relevance of gap junctions and large pore channels in traumatic brain injury. Front Physiol 2014; 5:31. [PMID: 24575046 PMCID: PMC3920098 DOI: 10.3389/fphys.2014.00031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/15/2014] [Indexed: 11/13/2022] Open
Abstract
In case of traumatic brain injury (TBI), occurrence of central nervous tissue damage is frequently aligned with local modulations of neuronal and glial gap junction channel expression levels. The degree of gap junctional protein expression and intercellular coupling efficiency, as well as hemichannel function has substantially impact on the course of trauma recovery and outcome. During TBI, gap junctions are especially involved in the intercellular molecule trafficking on repair of blood vessels and the regulation of vasomotor tone. Furthermore, gliosis and astrocytic swelling due to mechanical strain injury point out the consequences of derailed gap junction communication. This review addresses the outstanding role of gap junction channels in TBI pathophysiology and links the current state of results to applied clinical procedures as well as perspectives in acute and long-term treatment options.
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Affiliation(s)
- Nora Prochnow
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum Bochum, Germany
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10
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Cognitive impairments accompanying rodent mild traumatic brain injury involve p53-dependent neuronal cell death and are ameliorated by the tetrahydrobenzothiazole PFT-α. PLoS One 2013; 8:e79837. [PMID: 24312187 PMCID: PMC3842915 DOI: 10.1371/journal.pone.0079837] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/02/2013] [Indexed: 01/21/2023] Open
Abstract
With parallels to concussive mild traumatic brain injury (mTBI) occurring in humans, anesthetized mice subjected to a single 30 g weight drop mTBI event to the right parietal cortex exhibited significant diffuse neuronal degeneration that was accompanied by delayed impairments in recognition and spatial memory. To elucidate the involvement of reversible p53-dependent apoptosis in this neuronal loss and associated cognitive deficits, mice were subjected to experimental mTBI followed by the systemic administration of the tetrahydrobenzothiazole p53 inactivator, PFT-α, or vehicle. Neuronal loss was quantified immunohistochemically at 72 hr. post-injury by the use of fluoro-Jade B and NeuN within the dentate gyrus on both sides of the brain, and recognition and spatial memory were assessed by novel object recognition and Y-maze paradigms at 7 and 30 days post injury. Systemic administration of a single dose of PFT-α 1 hr. post-injury significantly ameliorated both neuronal cell death and cognitive impairments, which were no different from sham control animals. Cellular studies on human SH-SY5Y cells and rat primary neurons challenged with glutamate excitotoxicity and H2O2 induced oxidative stress, confirmed the ability of PFT-α and a close analog to protect against these TBI associated mechanisms mediating neuronal loss. These studies suggest that p53-dependent apoptotic mechanisms underpin the neuronal and cognitive losses accompanying mTBI, and that these are potentially reversible by p53 inactivation.
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Rachmany L, Tweedie D, Li Y, Rubovitch V, Holloway HW, Miller J, Hoffer BJ, Greig NH, Pick CG. Exendin-4 induced glucagon-like peptide-1 receptor activation reverses behavioral impairments of mild traumatic brain injury in mice. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1621-1636. [PMID: 22892942 PMCID: PMC3776106 DOI: 10.1007/s11357-012-9464-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 07/30/2012] [Indexed: 06/01/2023]
Abstract
Mild traumatic brain injury (mTBI) represents a major and increasing public health concern and is both the most frequent cause of mortality and disability in young adults and a chief cause of morbidity in the elderly. Albeit mTBI patients do not show clear structural brain defects and, generally, do not require hospitalization, they frequently suffer from long-lasting cognitive, behavioral, and emotional problems. No effective pharmaceutical therapy is available, and existing treatment chiefly involves intensive care management after injury. The diffuse neural cell death evident after mTBI is considered mediated by oxidative stress and glutamate-induced excitotoxicity. Prior studies of the long-acting GLP-1 receptor agonist, exendin-4 (Ex-4), an incretin mimetic approved for type 2 diabetes mellitus treatment, demonstrated its neurotrophic/protective activity in cellular and animal models of stroke, Alzheimer's and Parkinson's diseases, and, consequent to commonalities in mechanisms underpinning these disorders, Ex-4 was assessed in a mouse mTBI model. In neuronal cultures in this study, Ex-4 ameliorated H2O2-induced oxidative stress and glutamate toxicity. To evaluate in vivo translation, we administered steady-state Ex-4 (3.5 pM/kg/min) or saline to control and mTBI mice over 7 days starting 48 h prior to or 1 h post-sham or mTBI (30 g weight drop under anesthesia). Ex-4 proved well-tolerated and fully ameliorated mTBI-induced deficits in novel object recognition 7 and 30 days post-trauma. Less mTBI-induced impairment was evident in Y-maze, elevated plus maze, and passive avoidance paradigms, but when impairment was apparent Ex-4 induced amelioration. Together, these results suggest that Ex-4 may act as a neurotrophic/neuroprotective drug to minimize mTBI impairment.
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Affiliation(s)
- Lital Rachmany
- Department of Anatomy and Anthropology, Sackler School of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Li WA, Moore-Langston S, Chakraborty T, Rafols JA, Conti AC, Ding Y. Hyperglycemia in stroke and possible treatments. Neurol Res 2013; 35:479-91. [PMID: 23622737 DOI: 10.1179/1743132813y.0000000209] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hyperglycemia affects approximately one-third of acute ischemic stroke patients and is associated with poor clinical outcomes. In experimental and clinical stroke studies, hyperglycemia has been shown to be detrimental to the penumbral tissue for several reasons. First, hyperglycemia exacerbates both calcium imbalance and the accumulation of reactive oxygen species (ROS) in neurons, leading to increased apoptosis. Second, hyperglycemia fuels anaerobic energy production, causing lactic acidosis, which further stresses neurons in the penumbral regions. Third, hyperglycemia decreases blood perfusion after ischemic stroke by lowering the availability of nitric oxide (NO), which is a crucial mediator of vasodilation. Lastly, hyperglycemia intensifies the inflammatory response after stroke, causing edema, and hemorrhage through disruption of the blood brain barrier and degradation of white matter, which leads to a worsening of functional outcomes. Many neuroprotective treatments addressing hyperglycemia in stroke have been implemented in the past decade. Early clinical use of insulin provided mixed results due to insufficiently controlled glucose levels and heterogeneity of patient population. Recently, however, the latest Stroke Hyperglycemia Insulin Network Effort trial has addressed the shortcomings of insulin therapy. While glucagon-like protein-1 administration, hyperbaric oxygen preconditioning, and ethanol therapy appear promising, these treatments remain in their infancy and more research is needed to better understand the mechanisms underlying hyperglycemia-induced injuries. Elucidation of these mechanistic pathways could lead to the development of rational treatments that reduce hyperglycemia-associated injuries and improve functional outcomes for ischemic stroke patients.
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Affiliation(s)
- William A Li
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA
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Cheng G, Kong RH, Zhang LM, Zhang JN. Mitochondria in traumatic brain injury and mitochondrial-targeted multipotential therapeutic strategies. Br J Pharmacol 2013; 167:699-719. [PMID: 23003569 DOI: 10.1111/j.1476-5381.2012.02025.x] [Citation(s) in RCA: 232] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Traumatic brain injury (TBI) is a major health and socioeconomic problem throughout the world. It is a complicated pathological process that consists of primary insults and a secondary insult characterized by a set of biochemical cascades. The imbalance between a higher energy demand for repair of cell damage and decreased energy production led by mitochondrial dysfunction aggravates cell damage. At the cellular level, the main cause of the secondary deleterious cascades is cell damage that is centred in the mitochondria. Excitotoxicity, Ca(2+) overload, reactive oxygen species (ROS), Bcl-2 family, caspases and apoptosis inducing factor (AIF) are the main participants in mitochondria-centred cell damage following TBI. Some preclinical and clinical results of mitochondria-targeted therapy show promise. Mitochondria- targeted multipotential therapeutic strategies offer new hope for the successful treatment of TBI and other acute brain injuries.
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Affiliation(s)
- Gang Cheng
- Neurosurgical Department, PLA Navy General Hospital, Beijing, China
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14
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Martín A, Gómez-Vallejo V, San Sebastián E, Padró D, Markuerkiaga I, Llarena I, Llop J. In vivo imaging of dopaminergic neurotransmission after transient focal ischemia in rats. J Cereb Blood Flow Metab 2013; 33:244-52. [PMID: 23149560 PMCID: PMC3564194 DOI: 10.1038/jcbfm.2012.162] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The precise biologic mechanisms involved in functional recovery processes in response to stroke such as dopaminergic neurotransmission are still largely unknown. For this purpose, we performed in parallel in vivo magnetic resonance imaging and positron emission tomography (PET) with [(18)F]fluorodeoxyglucose ([(18)F]FDG) and [(11)C]raclopride at 1, 3, 7, 14, 21, and 28 days after middle cerebral artery occlusion in rats. In the ischemic territory, PET [(18)F]FDG showed a initial decrease in cerebral metabolism followed by a time-dependent recovery to quasi-normal values at day 14 after ischemia. The PET with [(11)C]raclopride, a ligand for dopamine D(2) receptor, showed a sustained binding during the first week after ischemia that declined dramatically from day 14 to day 28. Interestingly, a slight increase in [(11)C]raclopride binding was observed at days 1 to 3 followed by the uppermost binding at day 7 in the contralateral territory. Likewise, in vitro autoradiography using [(3)H]raclopride confirmed these in vivo results. Finally, the neurologic test showed major neurologic impairment at day 1 followed by a recovery of the cerebral function at day 28 after cerebral ischemia. Taken together, these results might suggest that dopamine D(2) receptor changes in the contralateral hemisphere could have a key role in functional recovery after cerebral ischemia.
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Affiliation(s)
- Abraham Martín
- Molecular Imaging Unit, CIC biomaGUNE, San Sebastián, Spain.
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15
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Keddy PGW, Dunlop K, Warford J, Samson ML, Jones QRD, Rupasinghe HPV, Robertson GS. Neuroprotective and anti-inflammatory effects of the flavonoid-enriched fraction AF4 in a mouse model of hypoxic-ischemic brain injury. PLoS One 2012; 7:e51324. [PMID: 23251498 PMCID: PMC3520852 DOI: 10.1371/journal.pone.0051324] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/31/2012] [Indexed: 11/23/2022] Open
Abstract
We report here neuroprotective and anti-inflammatory effects of a flavonoid-enriched fraction isolated from the peel of Northern Spy apples (AF4) in a mouse of model of hypoxic-ischemic (HI) brain damage. Oral administration of AF4 (50 mg/kg, once daily for 3 days) prior to 50 min of HI completely prevented motor performance deficits assessed 14 days later that were associated with marked reductions in neuronal cell loss in the dorsal hippocampus and striatum. Pre-treatment with AF4 (5, 10, 25 or 50 mg/kg, p.o.; once daily for 3 days) produced a dose-dependent reduction in HI-induced hippocampal and striatal neuron cell loss, with 25 mg/kg being the lowest dose that achieved maximal neuroprotection. Comparison of the effects of 1, 3 or 7 doses of AF4 (25 mg/kg; p.o.) prior to HI revealed that at least 3 doses of AF4 were required before HI to reduce neuronal cell loss in both the dorsal hippocampus and striatum. Quantitative RT-PCR measurements revealed that the neuroprotective effects of AF4 (25 mg/kg; p.o.; once daily for 3 days) in the dorsal hippocampus were associated with a suppression of HI-induced increases in the expression of IL-1β, TNF-α and IL-6. AF4 pre-treatment enhanced mRNA levels for pro-survival proteins such as X-linked inhibitor of apoptosis and erythropoietin following HI in the dorsal hippocampus and striatum, respectively. Primary cultures of mouse cortical neurons incubated with AF4 (1 µg/ml), but not the same concentrations of either quercetin or quercetin-3-O-glucose or its metabolites, were resistant to cell death induced by oxygen glucose deprivation. These findings suggest that the inhibition of HI-induced brain injury produced by AF4 likely involves a transcriptional mechanism resulting from the co-operative actions of various phenolics in this fraction which not only reduce the expression of pro-inflammatory mediators but also enhance pro-survival gene signalling.
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Affiliation(s)
- Paul G. W. Keddy
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kate Dunlop
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jordan Warford
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michel L. Samson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Quinton R. D. Jones
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - H. P. Vasantha Rupasinghe
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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16
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Susín C, Morales-Garcia JA, Aguilar-Morante D, Palomo V, Sanz-Sancristobal M, Alonso-Gil S, Gil C, Santos A, Martinez A, Perez-Castillo A. The new iminothiadiazole derivative VP1.14 ameliorates hippocampal damage after an excitotoxic injury. J Neurochem 2012; 122:1193-202. [DOI: 10.1111/j.1471-4159.2012.07866.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Anticonvulsant and neuroprotective effects of Pimpinella anisum in rat brain. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 12:76. [PMID: 22709243 PMCID: PMC3416669 DOI: 10.1186/1472-6882-12-76] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 06/18/2012] [Indexed: 12/04/2022]
Abstract
Background Essential oil of Pimpinella anisum L. Apiaceae (anise oil) has been widely used in traditional Persian medicine to treat a variety of diseases, including some neurological disorders. This study was aimed to test the possible anti-seizure and anti-hypoxia effects of anise oil. Methods The effects of different concentrations of anise oil were tested on seizure attacks induced by pentylenetetrazol (PTZ) injection and neuronal hypoxia induced by oxygen withdrawal as well as on production of dark neurons and induction of long-term potentiation (LTP) in in vivo and in vitro experimental models of rat brain. Results Anise oil significantly prolonged the latency of seizure attacks and reduced the amplitude and duration of epileptiform burst discharges induced by injection of intraperitoneal PTZ. In addition, anise oil significantly inhibited production of dark neurons in different regions of the brain in epileptic rats. Anise oil also significantly enhanced the duration of the appearance of anoxic terminal negativity induced by oxygen withdrawal and inhibited induction of LTP in hippocampal slices. Conclusions Our data indicate the anticonvulsant and neuroprotective effects of anise oil, likely via inhibition of synaptic plasticity. Further evaluation of anise oil to use in the treatment of neurological disorders is suggested.
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18
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Kritis A, Pourzitaki C, Klagas I, Chourdakis M, Albani M. Proteases inhibition assessment on PC12 and NGF treated cells after oxygen and glucose deprivation reveals a distinct role for aspartyl proteases. PLoS One 2011; 6:e25950. [PMID: 22028798 PMCID: PMC3196512 DOI: 10.1371/journal.pone.0025950] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 09/14/2011] [Indexed: 11/24/2022] Open
Abstract
Hypoxia is a severe stressful condition and induces cell death leading to neuronal loss both to the developing and adult nervous system. Central theme to cellular death is the activation of different classes of proteases such as caspases calpains and cathepsins. In the present study we investigated the involvement of these proteases, in the hypoxia-induced PC12 cell death. Rat PC12 is a model cell line for experimentation relevant to the nervous system and several protocols have been developed for either lethal hypoxia (oxygen and glucose deprivation OGD) or ischemic preconditioning (IPS). Nerve Growth Factor (NGF) treated PC12 differentiate to a sympathetic phenotype, expressing neurites and excitability. Lethal hypoxia was established by exposing undifferentiated and NGF-treated PC12 cells to a mixture of N2/CO2 (93:5%) in DMEM depleted of glucose and sodium pyruvate for 16 h. The involvement of caspases, calpains and lysosomal cathepsins D and E to the cell death induced by lethal OGD was investigated employing protease specific inhibitors such as z-VAD-fmk for the caspases, MDL28170 for the calpains and pepstatin A for the cathepsins D and E. Our findings show that pepstatin A provides statistically significant protection from cell death of both naive and NGF treated PC12 cells exposed to lethal OGD. We propose that apart from the established processes of apoptosis and necrosis that are integral components of lethal OGD, the activation of cathepsins D and E launches additional cell death pathways in which these proteases are key partners.
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Affiliation(s)
- Aristidis Kritis
- Laboratory of Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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19
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Hermann DM. Future Perspectives for Brain Pharmacotherapies: Implications of Drug Transport Processes at the Blood-brain Barrier. Ther Adv Neurol Disord 2011; 1:167-79. [PMID: 21180575 DOI: 10.1177/1756285608097775] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Years ago, ischemic stroke was regarded as a model disease for the development of neuroprotective therapies by the pharmacological industry. Results were disappointing. There are still no treatments available allowing the rescue of brain tissue once a stroke has occurred. Study failure is not only a problem in the stroke field. In other neurodegenerative conditions and in non-degenerative brain disorders, progress in drug development was also rather scarce until recently. An important factor in drug failure is the blood-brain barrier, which expresses active transporters that eliminate drugs from the brain. These transporters exhibit strong variations between different animals, which make it difficult to predict brain concentrations of drugs over species barriers. This paper claims that more detailed knowledge about: (1) the biology of blood-brain barrier transporters; (2) their regulation in brain disease, (3) the affinity of transporters to candidate drugs; and (4) the accumulation of drugs in brain tissue is needed for the overall success of clinical trials to be improved. An alternative strategy could be the use of disease-modifying treatments that do not have to enter the brain to exert their function. As such, restorative and anti-inflammatory strategies acting at the blood-brain interface might gain therapeutic potential in the future.
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Affiliation(s)
- Dirk M Hermann
- Chair of Vascular Neurology and Dementia, Department of Neurology, University Hospital Essen, Essen, Germany
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20
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Seo DW, Lopez-Meraz ML, Allen S, Wasterlain CG, Niquet J. Contribution of a mitochondrial pathway to excitotoxic neuronal necrosis. J Neurosci Res 2009; 87:2087-94. [PMID: 19235896 DOI: 10.1002/jnr.22035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
It is traditionally thought that excitotoxic necrosis is a passive mechanism that does not require the activation of a cell death program. In this study, we examined the contribution of the cytochrome c-dependent mitochondrial death pathway to excitotoxic neuronal necrosis, induced by exposing cultured cortical neurons to 1 mM glutamate for 6 hr and blocked by the NMDA antagonist, dizocilpine. Glutamate treatment induced early cytochrome c release, followed by activation of caspase-9 and caspase-3. Preincubation with the caspase-9 inhibitor z-LEHD-fmk, the caspase-3 inhibitor z-DEVD-fmk, or the specific pan-caspase inhibitor Q-VD-oph decreased the percentage of propidium iodide-positive neurons (52.5% +/- 3.1%, 39.4% +/- 3.5%, 44.6% +/- 3%, respectively, vs. 65% +/- 3% in glutamate + vehicle). EM studies showed mitochondrial release of cytochrome c in neurons in the early stages of necrosis and cleaved caspase-3 immunoreactivity in morphologically necrotic neurons. These results suggest that an active mechanism contributes to the demise of a subpopulation of excitotoxic necrotic neurons.
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Affiliation(s)
- Dae-Won Seo
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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21
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Ischemia independent lesion evolution during focal stroke in rats. Exp Neurol 2009; 218:41-6. [PMID: 19348795 DOI: 10.1016/j.expneurol.2009.03.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2008] [Revised: 02/25/2009] [Accepted: 03/26/2009] [Indexed: 11/20/2022]
Abstract
Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia. Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[14C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections. Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g(-1) min(-1) existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 +/- 21 mm3 (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct. Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.
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Cortes-Canteli M, Luna-Medina R, Sanz-Sancristobal M, Alvarez-Barrientos A, Santos A, Perez-Castillo A. CCAAT/enhancer binding protein beta deficiency provides cerebral protection following excitotoxic injury. J Cell Sci 2008; 121:1224-34. [PMID: 18388310 DOI: 10.1242/jcs.025031] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The CCAAT/enhancer-binding protein beta (C/EBPbeta, also known as CEBPB) was first identified as a regulator of differentiation and inflammatory processes in adipose tissue and liver. Although C/EBPbeta was initially implicated in synaptic plasticity, its function in the brain remains largely unknown. We have previously shown that C/EBPbeta regulates the expression of genes involved in inflammatory processes and brain injury. Here, we have demonstrated that the expression of C/EBPbeta is notably increased in the hippocampus in a murine model of excitotoxicity. Mice lacking C/EBPbeta showed a reduced inflammatory response after kainic acid injection, and exhibited a dramatic reduction in pyramidal cell loss in the CA1 and CA3 subfields of the hippocampus. These data reveal an essential function for C/EBPbeta in the pathways leading to excitotoxicity-mediated damage and suggest that inhibitors of this transcription factor should be evaluated as possible neuroprotective therapeutic agents.
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Affiliation(s)
- Marta Cortes-Canteli
- Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Arturo Duperier, 4, Madrid, Spain
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23
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Moisse K, Welch I, Hill T, Volkening K, Strong MJ. Transient middle cerebral artery occlusion induces microglial priming in the lumbar spinal cord: a novel model of neuroinflammation. J Neuroinflammation 2008; 5:29. [PMID: 18606006 PMCID: PMC2474603 DOI: 10.1186/1742-2094-5-29] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Accepted: 07/07/2008] [Indexed: 11/10/2022] Open
Abstract
Background Middle cerebral artery occlusion (MCAo) in mice results in a brain infarct, the volume of which depends on the length of occlusion. Following permanent occlusion, neuropathological changes – including a robust glial inflammatory response – also occur downstream of the infarct in the spinal cord. Methods We have performed short, transient MCAo in mice to induce penumbral damage spanning the motor cortex. A 30 minute MCAo using a poly-L-lysine-coated intraluminal suture introduced through a common carotid artery incision was performed in 17 female C57BL/6 mice. Five sham-operated mice received common carotid artery ligation without insertion of the suture. Neurobehavioural assessments were performed during occlusion, immediately following reperfusion, and at 24 and 72 hours post-reperfusion. Routine histological and immunohistochemical studies were performed at 24 and 72 hours. Results In 11 of the surviving 16 mice subjected to MCAo, we observed a focal, subcortical necrotic lesion and a reproducible, diffuse cortical lesion with accompanying upper motor neuron involvement. This was associated with contralateral ventral spinal cord microglial priming without significant reactive astrocytosis or lower motor neuron degeneration. Conclusion The advantages to this method are that it yields a reproducible cortical lesion, the extent of which is predictable using behavioural testing during the period of ischemia, with upper motor neuron involvement and downstream priming, but not full activation, of microglia in the lumbar spinal cord. In addition, survival is excellent following the 30 minutes of occlusion, rendering this a novel and useful model for examining the effects of microglial priming in the spinal motor neuron pool.
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Affiliation(s)
- Katie Moisse
- Cell Biology Research Group, Robarts Research Institute, London, Ontario, Canada.
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Ginsberg MD. Neuroprotection for ischemic stroke: past, present and future. Neuropharmacology 2008; 55:363-89. [PMID: 18308347 DOI: 10.1016/j.neuropharm.2007.12.007] [Citation(s) in RCA: 535] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 12/03/2007] [Accepted: 12/06/2007] [Indexed: 12/30/2022]
Abstract
Neuroprotection for ischemic stroke refers to strategies, applied singly or in combination, that antagonize the injurious biochemical and molecular events that eventuate in irreversible ischemic injury. There has been a recent explosion of interest in this field, with over 1000 experimental papers and over 400 clinical articles appearing within the past 6 years. These studies, in turn, are the outgrowth of three decades of investigative work to define the multiple mechanisms and mediators of ischemic brain injury, which constitute potential targets of neuroprotection. Rigorously conducted experimental studies in animal models of brain ischemia provide incontrovertible proof-of-principle that high-grade protection of the ischemic brain is an achievable goal. Nonetheless, many agents have been brought to clinical trial without a sufficiently compelling evidence-based pre-clinical foundation. At this writing, around 160 clinical trials of neuroprotection for ischemic stroke have been initiated. Of the approximately 120 completed trials, two-thirds were smaller early-phase safety-feasibility studies. The remaining one-third were typically larger (>200 subjects) phase II or III trials, but, disappointingly, only fewer than one-half of these administered neuroprotective therapy within the 4-6h therapeutic window within which efficacious neuroprotection is considered to be achievable. This fact alone helps to account for the abundance of "failed" trials. This review presents a close survey of the most extensively evaluated neuroprotective agents and classes and considers both the strengths and weakness of the pre-clinical evidence as well as the results and shortcomings of the clinical trials themselves. Among the agent-classes considered are calcium channel blockers; glutamate antagonists; GABA agonists; antioxidants/radical scavengers; phospholipid precursor; nitric oxide signal-transduction down-regulator; leukocyte inhibitors; hemodilution; and a miscellany of other agents. Among promising ongoing efforts, therapeutic hypothermia, high-dose human albumin therapy, and hyperacute magnesium therapy are considered in detail. The potential of combination therapies is highlighted. Issues of clinical-trial funding, the need for improved translational strategies and clinical-trial design, and "thinking outside the box" are emphasized.
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Affiliation(s)
- Myron D Ginsberg
- Department of Neurology (D4-5), University of Miami Miller School of Medicine, Miami, FL 33101, USA.
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25
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Leistner S, Sander T, Burghoff M, Curio G, Trahms L, Mackert BM. Combined MEG and EEG methodology for non-invasive recording of infraslow activity in the human cortex. Clin Neurophysiol 2007; 118:2774-80. [PMID: 17905653 DOI: 10.1016/j.clinph.2007.08.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Revised: 07/17/2007] [Accepted: 08/04/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Periinfarct depolarisation and spreading depression represent key mechanisms of neuronal injury after stroke. Changes in cortical electrical potentials and magnetic fields in the very low frequency range are relevant parameters to characterize these events, which up to now have only been recorded invasively. In this study, we proved whether a non-invasive combined MEG/EEG recording technique is able to quantitatively monitor cortical infraslow activity in humans. METHODS We used repetitive very slow and slow right finger movements as a physiological motor activation paradigm to induce cortical infraslow activity. Infraslow fields were recorded over the left hemisphere using a modulation-based MEG technique. EEG was performed using 16 standard Ag-Cl electrodes that covered the left motor cortex. RESULTS We recorded stable focal motor-related infraslow magnetic field changes in seven out of seven subjects. We also found correlating infraslow electrical potential changes in three out of seven subjects. Slow finger movements generated significantly stronger field and potential changes than very slow movements. CONCLUSIONS This study demonstrates the technical feasibility of combined non-invasive electrical potential and magnetic field measurements to localize and quantitatively monitor physiological, low amplitude, infraslow cortical activity in humans. This specific combination of simultaneous recording techniques allows to benefit from the specific physical advantages of each method. SIGNIFICANCE This combined non-invasive MEG-EEG methodology is able to provide important information on infraslow neuronal activity originating from tangentially and radially oriented sources. Moreover, this dual approach has the potential to separate neuronal from non-neuronal DC-sources, e.g., radially to the head orientated DC-currents across the skin/scalp/skull/dura occurring during cerebral hypercapnia or hypoxia.
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Affiliation(s)
- Stefanie Leistner
- Department of Neurology, Campus Benjamin Franklin, Charite-Universitätsmedizin Berlin, Hindenburgdamm 30, D-12200, Berlin, Germany.
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26
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Talhouk RS, Zeinieh MP, Mikati MA, El-Sabban ME. Gap junctional intercellular communication in hypoxia-ischemia-induced neuronal injury. Prog Neurobiol 2007; 84:57-76. [PMID: 18006137 DOI: 10.1016/j.pneurobio.2007.10.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 08/29/2007] [Accepted: 10/04/2007] [Indexed: 01/07/2023]
Abstract
Brain hypoxia-ischemia is a relatively common and serious problem in neonates and in adults. Its consequences include long-term histological and behavioral changes and reduction in seizure threshold. Gap junction intercellular communication is pivotal in the spread of hypoxia-ischemia related injury and in mediating its long-term effects. This review provides a comprehensive and critical review of hypoxia-ischemia and hypoxia in the brain and the potential role of gap junctions in the spread of the neuronal injury induced by these insults. It also presents the effects of hypoxia-ischemia and of hypoxia on the state of gap junctions in vitro and in vivo. Understanding the mechanisms involved in gap junction-mediated neuronal injury due to hypoxia will lead to the development of novel therapeutic strategies.
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Affiliation(s)
- Rabih S Talhouk
- Department of Biology, American University of Beirut, Beirut, Lebanon
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27
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Abstract
✓Cerebral edema is caused by a variety of pathological conditions that affect the brain. It is associated with two separate pathophysiological processes with distinct molecular and physiological antecedents: those related to cytotoxic (cellular) edema of neurons and astrocytes, and those related to transcapillary flux of Na+and other ions, water, and serum macromolecules. In this review, the authors focus exclusively on the first of these two processes. Cytotoxic edema results from unchecked or uncompensated influx of cations, mainly Na+, through cation channels. The authors review the different cation channels that have been implicated in the formation of cytotoxic edema of astrocytes and neurons in different pathological states. A better understanding of these molecular mechanisms holds the promise of improved treatments of cerebral edema and of the secondary injury produced by this pathological process.
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Affiliation(s)
- Danny Liang
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland 21201-1595, USA
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28
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Choi JK, Dedeoglu A, Jenkins BG. Application of MRS to mouse models of neurodegenerative illness. NMR IN BIOMEDICINE 2007; 20:216-37. [PMID: 17451183 DOI: 10.1002/nbm.1145] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The rapid development of transgenic mouse models of neurodegenerative diseases, in parallel with the rapidly expanding growth of MR techniques for assessing in vivo, non-invasive, neurochemistry, offers the potential to develop novel markers of disease progression and therapy. In this review we discuss the interpretation and utility of MRS for the study of these transgenic mouse and rodent models of neurodegenerative diseases such as Alzheimer's (AD), Huntington's (HD) and Parkinson's disease (PD). MRS studies can provide a wealth of information on various facets of in vivo neurochemistry, including neuronal health, gliosis, osmoregulation, energy metabolism, neuronal-glial cycling, and molecular synthesis rates. These data provide information on the etiology, natural history and therapy of these diseases. Mouse models enable longitudinal studies with useful time frames for evaluation of neuroprotection and therapeutic interventions using many of the potential MRS markers. In addition, the ability to manipulate the genome in these models allows better mechanistic understanding of the roles of the observable neurochemicals, such as N-acetylaspartate, in the brain. The argument is made that use of MRS, combined with correlative histology and other MRI techniques, will enable objective markers with which potential therapies can be followed in a quantitative fashion.
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Affiliation(s)
- Ji-Kyung Choi
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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29
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Kreisel SH, Hennerici MG, Bäzner H. Pathophysiology of stroke rehabilitation: the natural course of clinical recovery, use-dependent plasticity and rehabilitative outcome. Cerebrovasc Dis 2006; 23:243-55. [PMID: 17192704 DOI: 10.1159/000098323] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Accepted: 07/07/2006] [Indexed: 11/19/2022] Open
Abstract
Even though the disruption of motor activity and function caused by stroke is at times severe, recovery is often highly dynamic. Recuperation reflects the ability of the neuronal network to adapt. Next to an unmasking of latent network representations, other adaptive processes, such as excitatory metabolic stress, an imbalance in activating and inhibiting transmission, leading to salient hyperexcitability, or the consolidation of novel connections, prime the plastic capabilities of the system. Rehabilitative interventions may modulate mechanisms of neurofunctional plasticity and influence the natural course after stroke, both positively, but potentially also acting detrimentally. Though routine rehabilitative procedures are an integral part of stroke care, evidence as to their effectiveness remains equivocal. The present review describes the natural course of motor recovery, focusing on ischemic stroke, and discusses use- and training-dependent adaptive effects. It complements a prior article which highlighted the pathophysiology of plasticity. Though the interaction between rehabilitation and plasticity remains elusive, an attempt is made to clarify how and to what extent rehabilitative therapy shapes motor recovery.
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Affiliation(s)
- Stefan H Kreisel
- Department of Neurology, Universitätsklinikum Mannheim, University of Heidelberg, Heidelberg, Germany.
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30
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Linke S, Goertz P, Baader SL, Gieselmann V, Siebler M, Junghans U, Kappler J. Aldolase C/Zebrin II is Released to the Extracellular Space after Stroke and Inhibits the Network Activity of Cortical Neurons. Neurochem Res 2006; 31:1297-303. [PMID: 17053973 DOI: 10.1007/s11064-006-9169-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 09/13/2006] [Indexed: 01/01/2023]
Abstract
Cell death after stroke involves apoptotic, autophagocytic and necrotic mechanisms which may cause the release of cytosolic proteins to the extracellular space. Aldolase C (AldC) is the brain specific isoform of the glycolytic enzyme fructose-1,6-bisphosphate aldolase. According to its characteristic striped expression pattern in the adult cerebellum AldC is also termed zebrin II. Here, we demonstrate release of AldC into the cerebrospinal fluid (CSF) after stroke in vivo. Studies with cell cultures confirmed that AldC is released to the extracellular space after hypoxia. Moreover, addition of purified recombinant AldC to networks of cortical neurons plated on multielectrode arrays reversibly inhibited the spontaneous generation of action potentials at AldC concentrations which can be expected to occur after lesions of the human cerebral cortex. This mechanism could be relevant in the pathogenesis of the electrophysiological changes in the penumbra region after stroke.
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Affiliation(s)
- Stephanie Linke
- Institut für Physiologische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 11, D-53115, Bonn, Germany
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31
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Hossmann KA. Pathophysiology and Therapy of Experimental Stroke. Cell Mol Neurobiol 2006; 26:1057-83. [PMID: 16710759 DOI: 10.1007/s10571-006-9008-1] [Citation(s) in RCA: 308] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Accepted: 01/23/2006] [Indexed: 12/28/2022]
Abstract
1. Stroke is the neurological evidence of a critical reduction of cerebral blood flow in a circumscribed part of the brain, resulting from the sudden or gradually progressing obstruction of a large brain artery. Treatment of stroke requires the solid understanding of stroke pathophysiology and involves a broad range of hemodynamic and molecular interventions. This review summarizes research that has been carried out in many laboratories over a long period of time, but the main focus will be on own experimental research. 2. The first chapter deals with the hemodynamics of focal ischemia with particular emphasis on the collateral circulation of the brain, the regulation of blood flow and the microcirculation. In the second chapter the penumbra concept of ischemia is discussed, providing a detailed list of the physiological, biochemical and structural viability thresholds of ischemia and examples of how these thresholds can be applied for imaging the penumbra. The third chapter summarizes the pathophysiology of infarct progression, focusing on the role of peri-infarct depolarisation, the multitude of putative molecular injury pathways, brain edema and inflammation. Finally, the fourth chapter provides an overview of currently discussed therapeutic approaches, notably the effect of mechanical or thrombolytic reperfusion, arteriogenesis, pharmacological neuroprotection, ischemic preconditioning and regeneration. 3. The main emphasis of the review is placed on the balanced differentiation between hemodynamic and molecular factors contributing to the manifestation of ischemic injury in order to provide a rational basis for future therapeutic interventions.
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32
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Beresewicz M, Kowalczyk JE, Zabłocka B. Cytochrome c binds to inositol (1,4,5) trisphosphate and ryanodine receptors in vivo after transient brain ischemia in gerbils. Neurochem Int 2006; 48:568-71. [PMID: 16513219 DOI: 10.1016/j.neuint.2005.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Revised: 11/23/2005] [Accepted: 11/29/2005] [Indexed: 11/30/2022]
Abstract
Previously we have shown that the biphasic efflux of mitochondrial protein cytochrome c to cytoplasm is one of the important events of the delayed postichemic neuronal death. We concluded that early and transient appearance of cytochrome c in cytoplasm of cells recovering after ischemia was decisive for initiation of the pathological signaling cascade leading to neuronal death, but the precise mechanism remained unknown. In vitro cytochrome c was identified as a messenger that coordinates mitochondrial-endoplasmatic reticulum interactions that drive apoptosis. Here we show that in vivo cytochrome c interacts with inositol (1,4,5) trisphosphate receptor type 1 in gerbil hippocampus subjected to transient brain ischemia and short reperfusion. Moreover, cytochrome c binds also to ryanodine receptor type 2, the role of which in postischemic neuronal death is suggested. The complexes could be coimmunoprecipitated by antibodies against any of the two proteins. Our data verified that the mechanism observed in vitro applies to the pathological in vivo situation.
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Affiliation(s)
- Małgorzata Beresewicz
- Molecular Biology Unit, Mossakowski Medical Research Centre, PAS, 5 Pawińskiego, 02-106 Warsaw, Poland
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33
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Wang R, Yan H, Tang XC. Progress in studies of huperzine A, a natural cholinesterase inhibitor from Chinese herbal medicine. Acta Pharmacol Sin 2006; 27:1-26. [PMID: 16364207 DOI: 10.1111/j.1745-7254.2006.00255.x] [Citation(s) in RCA: 257] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Huperzine A (HupA), a novel alkaloid isolated from the Chinese herb Huperzia serrata, is a potent, highly specific and reversible inhibitor of acetylcholinesterase(AChE). Compared with tacrine, donepezil, and rivastigmine, HupA has better penetration through the blood-brain barrier, higher oral bioavailability, and longer duration of AChE inhibitory action. HupA has been found to improve cognitive deficits in a broad range of animal models. HupA possesses the ability to protect cells against hydrogen peroxide, beta-amyloid protein (or peptide), glutamate, ischemia and staurosporine-induced cytotoxicity and apoptosis. These protective effects are related to its ability to attenuate oxidative stress, regulate the expression of apoptotic proteins Bcl-2, Bax, P53, and caspase-3, protect mitochondria, upregulate nerve growth factor and its receptors, and interfere with amyloid precursor protein metabolism. Antagonizing effects of HupA on N-methyl-D-aspartate receptors and potassium currents may also contribute to its neuroprotection as well. Pharmacokinetic studies in rodents, canines, and healthy human volunteers indicated that HupA was absorbed rapidly, distributed widely in the body, and eliminated at a moderate rate with the property of slow and prolonged release after oral administration. Animal and clinical safety tests showed that HupA had no unexpected toxicity, particularly the dose-limiting hepatotoxicity induced by tacrine. The phase IV clinical trials in China have demonstrated that HupA significantly improved memory deficits in elderly people with benign senescent forgetfulness, and patients with Alzheimer disease and vascular dementia, with minimal peripheral cholinergic side effects and no unexpected toxicity. HupA can also be used as a protective agent against organophosphate intoxication.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China
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34
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Stumm R, Rüthrich H, Schulz S, Zhou C, Hollt V. Expression of the mu-opioid receptor is induced in dentate gyrus granule cells after focal cerebrocortical ischaemia and stimulation of entorhinal afferents. Eur J Neurosci 2005; 22:1032-44. [PMID: 16176345 DOI: 10.1111/j.1460-9568.2005.04296.x] [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: 02/04/2023]
Abstract
Focal ischaemia in the cerebral cortex affects the inducibility of long-term potentiation (LTP) in the hippocampus. This impairment of hippocampal function may result from excessive activation of cortico-hippocampal afferents and subsequent perturbation of hippocampal LTP-relevant transmitter systems, which include opioids. Here, we tested if permanent focal ischaemia and electrical afferent stimulation influence the expression of the mu-opioid receptor (MOR) in the rat hippocampus. In the applied ischaemia model, the entire ipsilateral cortical hemisphere and hippocampus experienced sustained excitation as indicated by a long-lasting increase in the expression of arg 3.1/arc (ARG) mRNA, a marker for neuronal activity. Expression of MOR mRNA and protein was strongly increased in granule cells, which contain very low MOR levels under normal conditions, but not in gamma-aminobutyric acid (GABA)ergic neurons, which express the MOR constitutively. In the molecular layer, which contains the dendrites of granule cells, focal ischaemia caused a redistribution of MOR-like immunoreactivity. In contrast to the dentate gyrus, MOR expression was unaltered in the hippocampus proper and in non-infarcted cortical areas. Repetitive high-frequency stimulation of cortico-hippocampal perforant path afferents induced strong MOR mRNA expression throughout the granular layer. However, weak tetanization sufficient to induce LTP and ARG expression did not influence MOR mRNA levels. Taken together, we provide direct evidence for the induction of MOR expression in granule cells experiencing sustained excitation by cortical afferents. In activated, MOR-expressing granule cells, inhibitory opioids may counter-regulate glutamatergic excitation by the perforant path.
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Affiliation(s)
- Ralf Stumm
- Department of Pharmacology and Toxicology, Otto-von-Guericke University, 39120 Magdeburg, Germany.
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35
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Lu XCM, Williams AJ, Wagstaff JD, Tortella FC, Hartings JA. Effects of delayed intrathecal infusion of an NMDA receptor antagonist on ischemic injury and peri-infarct depolarizations. Brain Res 2005; 1056:200-8. [PMID: 16112094 DOI: 10.1016/j.brainres.2005.07.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Revised: 07/18/2005] [Accepted: 07/21/2005] [Indexed: 11/28/2022]
Abstract
The potent NMDA receptor antagonist, Conantokin-G (CGX-1007), a snail peptide, has an 8-h therapeutic window in rat focal cerebral ischemia. We hypothesized that the mechanism of neuroprotection is the inhibition of 'secondary phase' peri-infarct depolarizations (PIDs), recently shown to recur 6--24 h post-reperfusion. Rats were implanted with intrathecal (i.t.) catheters for drug delivery and DC-compatible electrodes for continuous PID monitoring and subjected to transient (2 h) middle cerebral artery occlusion. Four groups were studied. In two groups (C(40)C and C(20)C), continuous infusion of CGX--1007 was administered over 8--24 h post-occlusion at 0.1 microg/h (0.04 nmol/h) following either a 40- or 20-nmol bolus dose at 8 h. Another group (C(40)S) received the 40-nmol bolus followed by saline infusion, and a control group received saline. Intrathecal drug treatment reduced infarct volumes relative to controls by 61%, 31%, and 10% in C(40)C, C(40)S, and C(20)C groups, respectively, but also induced dose-dependent paralysis and elevated mortality. All rats had PID rates similar to the control group prior to treatment, but following treatment secondary phase PIDs were reduced by 47--57% in each drug group compared to controls. Because several animals exhibited PID inhibition but no neuroprotection, there was no significant correlation between these endpoints across groups. However, drug-treated animals that did not exhibit secondary phase PIDs prior to treatment had significantly smaller infarcts and reduced subsequent PID activity than corresponding control rats. Results suggest that post-reperfusion PIDs play a substantial, though still undefined pathogenic role in delayed maturation of cerebral infarction and NMDA receptor-targeted neuroprotection.
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Affiliation(s)
- X-C May Lu
- Division of Psychiatry and Neurosciences, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910, USA
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36
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Wang R, Tang XC. Neuroprotective effects of huperzine A. A natural cholinesterase inhibitor for the treatment of Alzheimer's disease. Neurosignals 2005; 14:71-82. [PMID: 15956816 DOI: 10.1159/000085387] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Accepted: 11/08/2004] [Indexed: 12/24/2022] Open
Abstract
Huperzine A (HupA), isolated from Chinese herb Huperzia serrata, is a potent, highly specific and reversible inhibitor of acetylcholinesterase. It has been found to reverse or attenuate cognitive deficits in a broad range of animal models. Clinical trials in China have demonstrated that HupA significantly relieves memory deficits in aged subjects, patients with benign senescent forgetfulness, Alzheimer's disease (AD) and vascular dementia (VD), with minimal peripheral cholinergic side effects compared with other AChEIs in use. HupA possesses the ability to protect cells against hydrogen peroxide, beta-amyloid protein (or peptide), glutamate, ischemia and staurosporine-induced cytotoxicity and apoptosis. These protective effects are related to its ability to attenuate oxidative stress, regulate the expression of apoptotic proteins Bcl-2, Bax, P53 and caspase-3, protect mitochondria, and interfere with APP metabolism. Antagonizing effects on NMDA receptors and potassium currents may contribute to the neuroprotection as well. It is also possible that the non-catalytic function of AChE is involved in neuroprotective effects of HupA. The therapeutic effects of HupA on AD or VD are probably exerted via a multi-target mechanism.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Zhangjiang Hi-Tech Park, Shanghai, China
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37
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Mokrushin AA, Pavlinova LI, Plekhanov AY. Heat Shock Protein HSP70 Increases the Resistance of Cortical Cells to Glutamate Excitotoxicity. Bull Exp Biol Med 2005; 140:1-5. [PMID: 16254606 DOI: 10.1007/s10517-005-0396-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Preincubation of cultured slices of the olfactory cortex of rat brain with heat shock protein in a concentration of 1 microg/ml protected the pre- and postsynaptic mechanisms of glutamatergic synaptic transmission from glutamate excitotoxicity (50 mM) inducing blockade of excitatory postsynaptic function and reducing presynaptic processes. It was hypothesized that heat shock protein protects AMPA and NMDA receptor-mediated processes.
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Affiliation(s)
- A A Mokrushin
- I. P. Pavlov Institute of Physiology, Russian Academy of Sciences; B. P. Konstantinov St. Petersburg Institute of Nuclear Researches, Russian Academy of Sciences, Gatchina.
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38
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Magnetic resonance spectroscopy of neurodegenerative illness. NEURODEGENER DIS 2005. [DOI: 10.1017/cbo9780511544873.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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39
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Vidwans AS, Hewett SJ. Enhanced release of synaptic glutamate underlies the potentiation of oxygen-glucose deprivation-induced neuronal injury after induction of NOS-2. Exp Neurol 2005; 190:91-101. [PMID: 15473983 DOI: 10.1016/j.expneurol.2004.06.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2004] [Revised: 06/05/2004] [Accepted: 06/10/2004] [Indexed: 10/26/2022]
Abstract
Reactive nitrogen oxide species (RNOS) may contribute to the progression/enhancement of ischemic injury by augmentation of glutamate release, reduction of glutamate uptake, or a combination of both. Consistent with this, induction of nitric oxide synthase (NOS-2) in murine neocortical cell cultures potentiated neuronal cell death caused by combined oxygen-glucose deprivation in association with a net increase in extracellular glutamate accumulation. However, uptake of glutamate via high affinity, sodium-dependent glutamate transporters was unimpaired by induction of NOS-2 under either aerobic or anaerobic conditions. Further, blocking possible routes of extra-synaptic glutamate release with NPPB [5-nitro-2-(3-phenylpropylamino)-benzoic acid], a volume-sensitive organic anion channel blocker, or TBOA (d,l-threo-beta-benzyloxyaspartate), an inhibitor of glutamate transport, exacerbated rather than ameliorated injury. Finally, treatment with riluzole or tetanus toxin attenuated the enhancement in both glutamate accumulation and oxygen-glucose deprivation-induced neuronal injury supporting the idea that increased synaptic release of glutamate underlies, at least in part, the potentiation of neuronal injury by RNOS after NOS-2 induction.
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Affiliation(s)
- Aniruddha S Vidwans
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
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40
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Hachimi-Idrissi S, Van Hemelrijck A, Michotte A, Smolders I, Sarre S, Ebinger G, Huyghens L, Michotte Y. Postischemic mild hypothermia reduces neurotransmitter release and astroglial cell proliferation during reperfusion after asphyxial cardiac arrest in rats. Brain Res 2004; 1019:217-25. [PMID: 15306256 DOI: 10.1016/j.brainres.2004.06.013] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2004] [Indexed: 12/15/2022]
Abstract
The present study investigated whether postischemic mild hypothermia attenuates the ischemia-induced striatal glutamate (GLU) and dopamine (DA) release, as well as astroglial cell proliferation in the brain. Anesthetized rats were exposed to 8 min of asphyxiation, including 5 min of cardiac arrest. The cardiac arrest was reversed to restoration of spontaneous circulation (ROSC), by brief external heart massage and ventilation within a period of 2 min. After the insult and during reperfusion, the extracellular glutamate and dopamine overflow increased to, respectively, 3000% and 5000% compared with the baseline values in the normothermic group and resulted in brain damage, ischemic neurons and gliosis. However, when hypothermia was induced for a period of 60 min after the insult and restoration of spontaneous circulation, the glutamate and dopamine overflows were not significantly different from that in the sham group. Histological analysis of the brain showed that postischemic mild hypothermia reduced brain damage, ischemic neurons, as well as astroglial cell proliferation. Thus, postischemic mild hypothermia reduces the excitotoxic process, brain damage, as well as astroglial cell proliferation during reperfusion. Moreover, these results emphasize the trigger effect of dopamine on the excitotoxic pathway.
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Affiliation(s)
- S Hachimi-Idrissi
- Department of Critical Care Medicine and Cerebral Resuscitation Research Group, van de Vrije Universiteit Brussel, Laarbeeklaan 101, Brussels B-1090, Belgium.
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41
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Abstract
Stroke is the third leading cause of death and the leading cause of long-term disability in the United States. Approximately 80% of all strokes are ischemic and there are limited therapies approved for the treatment of acute ischemic stroke. Understanding the mechanisms of ischemic brain damage is necessary for the development of innovative treatment strategies. In this review, we discuss the hemodynamic and molecular mechanisms of ischemic brain damage and the potential therapeutic strategies, including reperfusion and primary and secondary neuroprotection, and strategies for recovery of function, such as neural plasticity and stem cell transplantation. The effective treatment of ischemic stroke is likely to result from a combination of therapeutic modalities aimed at different mechanisms of ischemic brain damage and delivered at specific times after acute cerebral ischemia.
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Affiliation(s)
- Vallabh Janardhan
- Cerebrovascular Program, Department of Neurology and Neurosciences, University of Medicine and Dentistry of New Jersey, H 506, 185 South Orange Avenue, Newark, NJ 07103, USA
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42
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Maetzler W, Nitsch C, Bendfeldt K, Racay P, Vollenweider F, Schwaller B. Ectopic parvalbumin expression in mouse forebrain neurons increases excitotoxic injury provoked by ibotenic acid injection into the striatum. Exp Neurol 2004; 186:78-88. [PMID: 14980812 DOI: 10.1016/j.expneurol.2003.10.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Revised: 09/11/2003] [Accepted: 09/25/2003] [Indexed: 11/26/2022]
Abstract
A neuroprotective role for Ca(2+)-binding proteins in neurodegenerative conditions ranging from ischemia to Alzheimer's disease has been suggested in several studies. A key phenomenon in neurodegeneration is the Ca(2+)-mediated excitotoxicity brought about by the neurotransmitter glutamate. To evaluate the relative ability to resist excitotoxicity of neurons containing the slow-onset Ca(2+)-binding protein parvalbumin (PV), we injected the glutamate agonist ibotenic acid (IBO) into the striatum of adult mice ectopically expressing PV in neurons. Striatal ibotenic acid injection results in local nerve cell loss and reactive astrogliosis. Light microscopic evaluation, carried out after a delay of 2 and 4 weeks, reveals an enlarged and accelerated neurodegenerative process in mice ectopically expressing neuronal PV. Thus, PV is not neuroprotective, it rather enhances nerve cell death. This result implicates that the increase in cytosolic Ca(2+)-buffering capacity in the transgenic mice impairs other systems involved in Ca2+ sequestration. In addition, ultrastructural morphometric analysis shows that in neurons the mitochondrial volume is reduced in mice ectopically expressing neuronal PV. This is paralleled by a reduction in the amount of the mitochondrial marker enzyme cytochrome c oxidase subunit I (COXI). We conclude that alterations in the Ca(2+) homeostasis present in mice ectopically expressing neuronal PV are more deleterious under excitotoxic stress and largely outweigh the potential benefits of an increased Ca(2+)-buffering capacity resulting from PV.
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Affiliation(s)
- Walter Maetzler
- Section of Neuroanatomy, Institute of Anatomy, University of Basel, Switzerland
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43
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Delayed secondary phase of peri-infarct depolarizations after focal cerebral ischemia: relation to infarct growth and neuroprotection. J Neurosci 2004. [PMID: 14684862 DOI: 10.1523/jneurosci.23-37-11602.2003] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In focal cerebral ischemia, peri-infarct depolarizations (PIDs) cause an expansion of core-infarcted tissue into adjacent penumbral regions of reversible injury and have been shown to occur through 6 hr after injury. However, infarct maturation proceeds through 24 hr. Therefore, we studied PID occurrence through 72 hr after both transient and permanent middle cerebral artery occlusion (MCAo) via continuous DC recordings in nonanesthetized rats. PIDs occurred an average 13 times before reperfusion at 2 hr and then ceased for an average approximately 8 hr. After this quiescent period, PID activity re-emerged in a secondary phase, which reached peak incidence at 13 hr and consisted of a mean 52 PIDs over 2-24 hr. This phase corresponded to the period of infarct maturation; rates of infarct growth through 24 hr coincided with changes in PID frequency and peaked at 13 hr. In permanent MCAo, PIDs also occurred in a biphasic pattern with a mean of 78 events over 2-24 hr. Parameters of secondary phase PID incidence correlated with infarct volumes in transient and permanent ischemia models. The role of secondary phase PIDs in infarct development was further investigated in transient MCAo by treating rats with a high-affinity NMDA receptor antagonist at 8 hr after injury, which reduced post-treatment PID incidence by 57% and provided 37% neuroprotection. Topographic mapping with multielectrode recordings revealed multiple sources of PID initiation and patterns of propagation. These results suggest that PIDs contribute to the recruitment of penumbral tissue into the infarct core even after the restoration of blood flow and throughout the period of infarct maturation.
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44
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Paschen W. Mechanisms of neuronal cell death: diverse roles of calcium in the various subcellular compartments. Cell Calcium 2003; 34:305-10. [PMID: 12909077 DOI: 10.1016/s0143-4160(03)00138-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Wulf Paschen
- Department of Experimental Neurology, Max-Planck-Institute for Neurological Research, Cologne, Germany.
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45
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Borsello T, Clarke PGH, Hirt L, Vercelli A, Repici M, Schorderet DF, Bogousslavsky J, Bonny C. A peptide inhibitor of c-Jun N-terminal kinase protects against excitotoxicity and cerebral ischemia. Nat Med 2003; 9:1180-6. [PMID: 12937412 DOI: 10.1038/nm911] [Citation(s) in RCA: 549] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2003] [Accepted: 07/22/2003] [Indexed: 12/26/2022]
Abstract
Neuronal death in cerebral ischemia is largely due to excitotoxic mechanisms, which are known to activate the c-Jun N-terminal kinase (JNK) pathway. We have evaluated the neuroprotective power of a cell-penetrating, protease-resistant peptide that blocks the access of JNK to many of its targets. We obtained strong protection in two models of middle cerebral artery occlusion (MCAO): transient occlusion in adult mice and permanent occlusion in 14-d-old rat pups. In the first model, intraventricular administration as late as 6 h after occlusion reduced the lesion volume by more than 90% for at least 14 d and prevented behavioral consequences. In the second model, systemic delivery reduced the lesion by 78% and 49% at 6 and 12 h after ischemia, respectively. Protection correlated with prevention of an increase in c-Jun activation and c-Fos transcription. In view of its potency and long therapeutic window, this protease-resistant peptide is a promising neuroprotective agent for stroke.
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Affiliation(s)
- Tiziana Borsello
- Institut de Biologie Cellulaire et de Morphologie, Université de Lausanne, Rue du Bugnon 9, CH-1005, Switzerland.
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Leker RR, Constantini S. Experimental models in focal cerebral ischemia: are we there yet? ACTA NEUROCHIRURGICA. SUPPLEMENT 2003; 83:55-9. [PMID: 12442622 DOI: 10.1007/978-3-7091-6743-4_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Therapeutic options available for acute stroke management are sparse and inadequate. Therefore, new insights into stroke pathophysiology leading to new therapeutic targets are needed. In order to attain these goals, adequate animal models for cerebral ischemia are needed. In the following paper the authors will review the various animal models for stroke and emphasize their potential strengths and weaknesses.
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Affiliation(s)
- R R Leker
- Department of Neurology, Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital, Jerusalem, Israel
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Macaluso C, Frishman LJ, Frueh B, Kaelin-Lang A, Onoe S, Niemeyer G. Multiple effects of adenosine in the arterially perfused mammalian eye. Possible mechanisms for the neuroprotective function of adenosine in the retina. Doc Ophthalmol 2003; 106:51-9. [PMID: 12675486 DOI: 10.1023/a:1022456615715] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
It has been postulated that the major physiological role of adenosine is protection of the central nervous system in conditions such as ischemia, hypoxia, or prolonged neuronal excitation. Under these conditions adenosine is released, and exerts multiple effects, including vasodilation, inhibition of neuronal activity, and enhancement of glycogenolysis, resulting in neuroprotection. In this article, published as well as unpublished data on the multiple effects of exogenous adenosine and application of adenosine-related agents, performed using the arterially perfused cat eye, will be reviewed and discussed within the framework of the neuroprotective role of adenosine. The isolated, arterially perfused eye preparation has the advantage of combining integrity of the eye structure, exact control of arterial concentration and timing of applied pharmacological agents, and access to electrophysiological parameters of both retina and optic nerve, as well as the ability to control and monitor perfusate flow. The absence of red blood cells in the perfusate prevents adenosine from being metabolized prior to reaching the eye.
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Kilic E, Dietz GPH, Hermann DM, Bähr M. Intravenous TAT-Bcl-Xl is protective after middle cerebral artery occlusion in mice. Ann Neurol 2002; 52:617-22. [PMID: 12402259 DOI: 10.1002/ana.10356] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The delivery of proteins across the blood-brain barrier is severely limited by the proteins' size and biochemical properties. Eleven-amino acid human immunodeficiency virus TAT protein is able to cross cell membranes even when coupled with larger peptides. We evaluated whether TAT-Bcl-X(L) fusion protein is protective in focal ischemia. Mice underwent 30 or 90 minutes of intraluminal middle cerebral artery thread occlusion. TAT-Bcl-X(L), TAT-beta-galactosidase, or TAT-GFP (0.6 nmol each) were applied intravenously over 10 minutes either 1 hour before or immediately after ischemia. Additional animals received no TAT protein infusions. We show that the brain tissue is progressively transduced with TAT proteins within 3 to 4 hours after intravenous delivery. We provide evidence that TAT-Bcl-X(L) treatment reduces infarct volume and neurological deficits after long ischemic insults lasting 90 minutes, when applied both before and after ischemia. After short insults, lasting only 30 minutes, TAT-Bcl-X(L) further diminishes the number of caspase-3-reactive and DNA fragmented cells and increases the number of viable neurons in the striatum. Our results indicate that TAT fusion proteins are elegant and powerful tools that might be of clinical interest for stroke treatment, because factors may be intravenously applied. Thus, fusion proteins may open fascinating perspectives for future research.
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Affiliation(s)
- Ertugrul Kilic
- Department of Neurology, University of Göttingen, Robert-Koch-Strasse 40, D-37075 Göttingen, Germany.
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Kitagawa K, Matsumoto M, Hori M, Yanagihara T. Neuroprotective effect of apolipoprotein E against ischemia. Ann N Y Acad Sci 2002; 977:468-75. [PMID: 12480787 DOI: 10.1111/j.1749-6632.2002.tb04852.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Apolipoprotein E (APOE) deficiency has been shown to worsen neuronal injuries after cerebral ischemia. However, the molecular mechanism underlying the protective effect of APOE remains uncertain, even though several mechanisms including excitotoxicity, free radicals, and apoptosis have been cited as causes of selective neuronal vulnerability in cerebral ischemia. In the present study, we compared the vulnerability of cultured neurons prepared from APOE-knockout mice upon exposure to glutamate, hydrogen peroxide, and staurosporine. No significant difference in cell viability was observed after exposure to glutamate or staurosporine between APOE-deficient and wild-type mice. However, exposure to hydrogen peroxide significantly increased the level of cell death in APOE-deficient mice compared with that in wild-type mice. In the adult mice, after transient forebrain ischemia for 12 min, APOE-deficient mice showed more neuronal death than wild-type mice. Pretreatment of APOE-deficient mice with vitamin E for 2 months markedly reduced neuronal death caused by ischemia. The results suggested that APOE exerted the neuroprotective effect against ischemia through its antioxidant action, but not through mitigation of glutamate toxicity or blocking of apoptosis.
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Affiliation(s)
- Kazuo Kitagawa
- Division of Strokology, Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine (A8), 2-2 Yamadaoka, Suita-city, Osaka 565-0871, Japan.
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Sopala M, Danysz W, Quack G. Neuroprotective effects of NS-7, voltage-gated Na+/Ca2+ channel blocker in a rodent model of transient focal ischaemia. Neurotox Res 2002; 4:655-661. [PMID: 12709303 DOI: 10.1080/1029842021000045462] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of the present study was to characterize neuroprotective activity of NS- 7, a mixed voltage-gated sodium and calcium channel blocker in a model of transient focal ischaemia in rats. Ischaemia was induced by a 75 min reversible occlusion of middle cerebral artery (MCAo) using a nylon filament. NS-7 (0.5 mg/kg i.v.) or 0.9% NaCl (1 ml/kg i.v.) were infused over 3 min. starting 30 min after the MCAo. Infarct analysis was performed 72 h after ischaemia. Application of NS- 7 produced significant protection seen in neurological tests and diminished brain damage by 37% in total infarct (17.7+/- 3.0% vs. 27.9 +/- 3.2% control; [p < 0.01]; t-test), 47.8% in cortical infarct size by (8.5 +/- 2.4% vs. 16.2 +/- 2.4% control; [p < 0.01]), and by 21.5% in striatal infarction (9.2 +/- 0.8% vs. 11.7 +/- 0.9% control; [p < 0.05]). The results indicate that NS- 7 has potential for neuroprotection against transient ischaemic insult.
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Affiliation(s)
- Monika Sopala
- Merz Pharmaceuticals GmbH, Preclinical Research and Development, Eckenheimer Landstrasse 100, 60318 Frankfurt/Main, Germany
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