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Conti E, Carlini N, Piccardi B, Allegra Mascaro AL, Pavone FS. Photothrombotic Middle Cerebral Artery Occlusion in Mice: A Novel Model of Ischemic Stroke. eNeuro 2023; 10:ENEURO.0244-22.2022. [PMID: 36650068 PMCID: PMC9910575 DOI: 10.1523/eneuro.0244-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/25/2022] [Accepted: 11/06/2022] [Indexed: 01/19/2023] Open
Abstract
Stroke is one of the main causes of death and disability worldwide. Over the past decades, several animal models of focal cerebral ischemia have been developed allowing to investigate pathophysiological mechanisms underlying stroke progression. Despite intense preclinical research efforts, the need for noninvasive mouse models of vascular occlusion targeting the middle cerebral artery yet avoiding mechanical intervention is still pressing. Here, by applying the photothrombotic stroke model to the distal branch of the middle cerebral artery, we developed a novel strategy to induce a targeted occlusion of a large blood vessel in mice. This approach induces unilateral damage encompassing most of the dorsal cortex from the motor up to the visual regions 1 week after stroke. Pronounced limb dystonia one day after the damage is partially recovered after one week. Furthermore, we observe the insurgence of blood vessel leakage and edema formation in the peri-infarct area. Finally, this model elicits a notable inflammatory response revealed as a strong increase in astrocyte density and morphologic complexity in the perilesional region of the cortex compared with both other regions of the ipsilesional and contralesional hemispheres, and in sham-operated mice. To conclude, the stroke model we developed induces in mice the light-mediated occlusion of one of the main targets of human ischemic stroke, the middle cerebral artery, free from the limitations of commonly used preclinical models.
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Affiliation(s)
- Emilia Conti
- Neuroscience Institute, National Research Council, 56124 Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
- Translational Research on Stroke (TREES) Working Group, Florence, Italy
| | - Noemi Carlini
- Neuroscience Institute, National Research Council, 56124 Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
| | - Benedetta Piccardi
- Neurofarba Department, University of Florence, 50139 Florence, Italy
- Translational Research on Stroke (TREES) Working Group, Florence, Italy
| | - Anna Letizia Allegra Mascaro
- Neuroscience Institute, National Research Council, 56124 Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
- Translational Research on Stroke (TREES) Working Group, Florence, Italy
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, 50019 Sesto Fiorentino, Italy
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Singh AA, Kharwar A, Dandekar MP. A Review on Preclinical Models of Ischemic Stroke: Insights Into the Pathomechanisms and New Treatment Strategies. Curr Neuropharmacol 2022; 20:1667-1686. [PMID: 34493185 PMCID: PMC9881062 DOI: 10.2174/1570159x19666210907092928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/21/2021] [Accepted: 08/26/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Stroke is a serious neurovascular problem and the leading cause of disability and death worldwide. The disrupted demand to supply ratio of blood and glucose during cerebral ischemia develops hypoxic shock, and subsequently necrotic neuronal death in the affected regions. Multiple causal factors like age, sex, race, genetics, diet, and lifestyle play an important role in the occurrence as well as progression of post-stroke deleterious events. These biological and environmental factors may be contributed to vasculature variable architecture and abnormal neuronal activity. Since recombinant tissue plasminogen activator is the only clinically effective clot bursting drug, there is a huge unmet medical need for newer therapies for the treatment of stroke. Innumerous therapeutic interventions have shown promise in the experimental models of stroke but failed to translate it into clinical counterparts. METHODS Original publications regarding pathophysiology, preclinical experimental models, new targets and therapies targeting ischemic stroke have been reviewed since the 1970s. RESULTS We highlighted the critical underlying pathophysiological mechanisms of cerebral stroke and preclinical stroke models. We discuss the strengths and caveats of widely used ischemic stroke models, and commented on the potential translational problems. We also describe the new emerging treatment strategies, including stem cell therapy, neurotrophic factors and gut microbiome-based therapy for the management of post-stroke consequences. CONCLUSION There are still many inter-linked pathophysiological alterations with regards to stroke, animal models need not necessarily mimic the same conditions of stroke pathology and newer targets and therapies are the need of the hour in stroke research.
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Affiliation(s)
- Aditya A. Singh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Balanagar, TS 500037, India
| | - Akash Kharwar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Balanagar, TS 500037, India
| | - Manoj P. Dandekar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Balanagar, TS 500037, India,Address correspondence to this author at the Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Balanagar, TS 500037, India; Tel: +91-40-23074750; E-mail:
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Hypoxia Inducible Factor-1α Attenuates Ischemic Brain Damage by Modulating Inflammatory Response and Glial Activity. Cells 2021; 10:cells10061359. [PMID: 34205911 PMCID: PMC8229365 DOI: 10.3390/cells10061359] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 12/12/2022] Open
Abstract
Hypoxia-inducible factor 1 can sufficiently control the progress of neurological symptoms after ischemic stroke owing to their actions associated with its downstream genes. In this study, we evaluated the role of HIF-1α in attenuating brain damage after endothelin-1 injection. Focal cerebral ischemia in mice were induced by endothelin-1 microinjection. Hypoxia-inducible factor 1 activator, dimethyloxalylglycine (DMOG), and HIF-1α inhibitor, acriflavine (ACF), were used to evaluate the hypoxia-inducible factor 1 activity during cerebral ischemia. The expression levels of HIF-1α, glial fibrillary acidic protein (GFAP), interleukin-10 (IL-10), inducible nitric oxide synthase (iNOS), phosphorylated I-kappa-B-alpha/total I-kappa-B-alpha (p-IκBα/IκBα) and nuclear factor kappa B (NF-kB) were assessed. Besides, mRNA levels of IL-10, tumor necrosis factor- alpha (TNF-α), and NF-kB were also analyzed. Results showed a noticeable increase in hypoxia-inducible factor 1 and IL-10 levels in the DMOG group with a decline in iNOS, TNF-α, and NF-kB levels, implying the anti-inflammatory role of hypoxia-inducible factor 1 activator following stroke. These findings were further corroborated by GFAP immunostaining that showed astrocytic activation to be inhibited 12 days post-ischemia, as well as histological and TEM analyses that demonstrated hypoxia-inducible factor 1 induction to alleviate neuronal soma damage and cell death. Based on our study, HIF-1α could be a potential therapeutic target for ischemic stroke.
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Kuts R, Melamed I, Shiyntum HN, Gruenbaum BF, Frank D, Knyazer B, Natanel D, Severynovska O, Vinokur M, Boyko M. Laser-Induced Brain Injury in the Motor Cortex of Rats. J Vis Exp 2020. [PMID: 33044445 DOI: 10.3791/60928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
A common technique for inducing stroke in experimental rodent models involves the transient (often denoted as MCAO-t) or permanent (designated as MCAO-p) occlusion of the middle cerebral artery (MCA) using a catheter. This generally accepted technique, however, has some limitations, thereby limiting its extensive use. Stroke induction by this method is often characterized by high variability in the localization and size of the ischemic area, periodical occurrences of hemorrhage, and high death rates. Also, the successful completion of any of the transient or permanent procedures requires expertise and often lasts for about 30 minutes. In this protocol, a laser irradiation technique is presented that can serve as an alternative method for inducing and studying brain injury in rodent models. When compared to rats in the control and MCAO groups, the brain injury by laser induction showed reduced variability in body temperature, infarct volume, brain edema, intracranial hemorrhage, and mortality. Furthermore, the use of a laser-induced injury caused damage to the brain tissues only in the motor cortex unlike in the MCAO experiments where destruction of both the motor cortex and striatal tissues is observed. Findings from this investigation suggest that laser irradiation could serve as an alternative and effective technique for inducing brain injury in the motor cortex. The method also shortens the time for completing the procedure and does not require expert handlers.
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Affiliation(s)
- Ruslan Kuts
- Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev
| | - Israel Melamed
- Department of Neurosurgery, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev
| | - Honore N Shiyntum
- Department of Biochemistry and Physiology, Faculty of Biology, Ecology, and Medicine, Oles Honchar Dnipro National University
| | | | - Dmitri Frank
- Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev
| | - Boris Knyazer
- Department of Ophthalmology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev
| | - Dmitry Natanel
- Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev
| | - Olena Severynovska
- Department of Biochemistry and Physiology, Faculty of Biology, Ecology, and Medicine, Oles Honchar Dnipro National University
| | - Max Vinokur
- Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev
| | - Matthew Boyko
- Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev;
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Freire MAM, Santana LNS, Bittencourt LO, Nascimento PC, Fernandes RM, Leão LKR, Fernandes LMP, Silva MCF, Amado LL, Gomes-Leal W, Crespo-Lopez ME, Maia CDSF, Lima RR. Methylmercury intoxication and cortical ischemia: Pre-clinical study of their comorbidity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 174:557-565. [PMID: 30865911 DOI: 10.1016/j.ecoenv.2019.03.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/01/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
Stroke is one of the main causes of human disability worldwide. Ischemic stroke is mostly characterized by metabolic collapse and fast tissue damage, followed by secondary damage in adjacent regions not previously affected. Heavy metals intoxication can be associated with stroke incidence, because of their damaging action in the vascular system. Mercury, in particular, possesses a high tropism by metabolically active regions, such as the brain. In the present study we sought to evaluate whether methylmercury (MeHg) intoxication can aggravate the tissue damage caused by an ischemic stroke induced by microinjections of endothelin-1 (ET-1) into the motor cortex of adult rats. Following MeHg intoxication by gavage (0.04 mg/kg/day) during 60 days, the animals were injected with ET-1 (1 μl, 40 pmol/μl) or vehicle (1 μl). After 7 days, all animals were submitted to behavioral tests and then their brains were processed to biochemical and immunohistochemical analyses. We observed that long-term MeHg intoxication promoted a significant Hg deposits in the motor cortex, with concomitant increase of microglial response, followed by reduction of the neuronal population following ischemia and MeHg intoxication, as well as disturbance in the antioxidant defense mechanisms by misbalance of oxidative biochemistry with increase of both lipid peroxidation and nitrite levels, associated to behavioral deficits. MeHg exposure and cortical ischemia demonstrated that both injuries are able of causing significant neurobehavioural impairments in motor coordination and learning accompanied of an exacerbated microglial activation, oxidative stress and neuronal loss in the motor cortex, indicating that MeHg as a source of metabolic disturbance can act as an important increasing factor of ischemic events in the brain.
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Affiliation(s)
| | - Luana Nazaré S Santana
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Priscila Cunha Nascimento
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Rafael Monteiro Fernandes
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Luana Ketlen R Leão
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Luanna Melo P Fernandes
- Laboratory of Pharmacology of Inflammation and Behavior, Institute of Health Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Marcia Cristina F Silva
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Lílian Lund Amado
- Laboratory of Ecotoxicology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Walace Gomes-Leal
- Laboratory of Experimental Neuroprotection and Neuroregeneration, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Maria Elena Crespo-Lopez
- Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Cristiane do Socorro F Maia
- Laboratory of Pharmacology of Inflammation and Behavior, Institute of Health Sciences, Federal University of Pará, Belém, PA, Brazil
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil.
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Boyko M, Kuts R, Gruenbaum BF, Tsenter P, Grinshpun J, Frank D, Zvenigorodsky V, Melamed I, Brotfain E, Zlotnik A. An Alternative Model of Laser-Induced Stroke in the Motor Cortex of Rats. Biol Proced Online 2019; 21:9. [PMID: 31130825 PMCID: PMC6524336 DOI: 10.1186/s12575-019-0097-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/02/2019] [Indexed: 11/10/2022] Open
Abstract
Background A common experimental rodent model for stroke includes induction by a technique in which middle cerebral artery is transiently (MCAO-t) or permanently (MCAO-p) occluded by catheterization. However, this model has prominent disadvantages which consist of the high variability of localization and size of the ischemic area, cases of intracranial hemorrhage and high mortality. Furthermore, the duration of a single MCAO operation takes about thirty minutes and requires highly trained staff. In this article, we propose an alternative method, which is based on laser-induced stroke in the motor cortex. In our research, we compared the original MCAO-p and MCAO-t models and a novel laser model. Results Compared with the impact of original MCAO-p and MCAO-t technique on brain tissue, the minimally invasive laser model demonstrated a decrease in: variability in body temperature, percent of infarcted volume, blood brain barrier breakdown and brain edema, as well as a prominent decrease of mortality and intracranial hemorrhage. Among other findings of this article, it can be noted that damage to the brain tissue in laser groups occurred only in the region of the motor cortex, without involving the striatal area. Conclusions The data presented in this paper show that the model of laser irradiation can serve as an effective method of inducible brain cortical infarction and may lead to a better understanding of the pathophysiology of ischemic stroke and the future development of new drugs and other neuro-protective agents.
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Affiliation(s)
- Matthew Boyko
- 1Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Ruslan Kuts
- 1Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Benjamin F Gruenbaum
- 2Department of Anesthesiology, Yale University School of Medicine, New Haven, CT 06525 USA
| | - Philip Tsenter
- 3Division of Internal Medicine, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Julia Grinshpun
- 1Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Dmitry Frank
- 1Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Vladislav Zvenigorodsky
- 4Department of Radiology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Israel Melamed
- 5Department of Neurosurgery, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Evgeni Brotfain
- 1Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
| | - Alexander Zlotnik
- 1Division of Anesthesiology and Critical Care, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, 84101 Beer-Sheva, Israel
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Nowak TS, Mulligan MK. Impact of C57BL/6 substrain on sex-dependent differences in mouse stroke models. Neurochem Int 2018; 127:12-21. [PMID: 30448566 DOI: 10.1016/j.neuint.2018.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 01/18/2023]
Abstract
We have recently found significant variation in stroke vulnerability among substrains of C57BL/6 mice, observing that commonly used N-lineage substrains exhibit larger infarcts than C57BL/6J and related substrains. Parallel variation was also seen with respect to sex differences in stroke vulnerability, in that C57BL/6 mice of the N-lineage exhibited comparable infarct sizes in males and females, whereas infarcts tended to be smaller in females than in males of J-lineage substrains. This adds to the growing list of recognized phenotypic and genetic differences among C57BL/6 substrains. Although no previous studies have explicitly compared substrains with respect to sex differences in stroke vulnerability, unrecognized background mismatch has occurred in some studies involving control and genetically modified mice. The aims of this review are to: present the evidence for associated substrain- and sex-dependent differences in a mouse permanent occlusion stroke model; examine the extent to which the published literature in other models compares with these recent results; and consider the potential impact of unrecognized heterogeneity in substrain background on the interpretation of studies investigating the impact of genetic modifications on sex differences in stroke outcome. Substrain emerges as a critical variable to be documented in any experimental stroke study in mice.
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Affiliation(s)
- Thaddeus S Nowak
- Department of Neurology and Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - Megan K Mulligan
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, USA
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Neuroprotective Effects of Nasopharyngeal Perfluorochemical Cooling in a Rat Model of Subarachnoid Hemorrhage. World Neurosurg 2018; 121:e481-e492. [PMID: 30267945 DOI: 10.1016/j.wneu.2018.09.142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Subarachnoid hemorrhage (SAH) frequently results in severe morbidity, even mortality. Hypothermia is known to have a neuroprotective effect in ischemic injuries. The aim of this study was to determine whether nasopharyngeal (NP) perfluorochemical (PFC) cooling could be used in a rat model of SAH model for neuroprotection. METHODS SAH was induced in 16 male Sprague-Dawley rats by cisterna magna injection of 0.3 mL autologous blood. Vital signs, temperatures, cerebral blood flow (CBF), and brain histology were assessed. Brain cooling was performed on the treatment group using the NP-PFC method starting from 20 minutes after SAH. RESULTS No SAH-related deaths were observed in either group. SAH caused an immediate decrease in mean arterial pressure (17.0% ± 4.90% below baseline values). SAH induction caused a significant and rapid decrease in CBF from baseline (approximately -65%, ranging from -32% to -85%) in both hemispheres. In the left hemisphere, cooling facilitated the return of CBF to baseline values within 20 minutes of treatment with further increase in CBF that stabilized by the 2 hours after injury time point. Quantitative immunohistochemistry showed that there were significantly more NeuN-positive cells in the cortex and significantly fewer IBA-1-positive microglia and glial fibrillary acidic protein-positive astrocytes cells in both cortex and hippocampus in the animals that received NP-PFC cooling compared with no treatment, reflecting preserved neuronal integrity and reduced inflammation. CONCLUSIONS The data from this study indicate that local hypothermia by NP-PFC cooling supports return of CBF and neuronal integrity and suppresses the inflammatory response in SAH, suggestive of a promising neuroprotective approach in management of SAH.
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Lee S, Son B, Park G, Kim H, Kang H, Jeon J, Youn H, Youn B. Immunogenic Effect of Hyperthermia on Enhancing Radiotherapeutic Efficacy. Int J Mol Sci 2018; 19:E2795. [PMID: 30227629 PMCID: PMC6164993 DOI: 10.3390/ijms19092795] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 09/11/2018] [Accepted: 09/13/2018] [Indexed: 12/15/2022] Open
Abstract
Hyperthermia is a cancer treatment where tumor tissue is heated to around 40 °C. Hyperthermia shows both cancer cell cytotoxicity and immune response stimulation via immune cell activation. Immunogenic responses encompass the innate and adaptive immune systems, involving the activation of macrophages, natural killer cells, dendritic cells, and T cells. Moreover, hyperthermia is commonly used in combination with different treatment modalities, such as radiotherapy and chemotherapy, for better clinical outcomes. In this review, we will focus on hyperthermia-induced immunogenic effects and molecular events to improve radiotherapy efficacy. The beneficial potential of integrating radiotherapy with hyperthermia is also discussed.
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Affiliation(s)
- Sungmin Lee
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
| | - Beomseok Son
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
| | - Gaeul Park
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
| | - Hyunwoo Kim
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
| | - Hyunkoo Kang
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
| | - Jaewan Jeon
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
| | - HyeSook Youn
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul 05006, Korea.
| | - BuHyun Youn
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea.
- Department of Biological Sciences, Pusan National University, Busan 46241, Korea.
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Neurodegeneration and Glial Response after Acute Striatal Stroke: Histological Basis for Neuroprotective Studies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3173564. [PMID: 28090244 PMCID: PMC5165163 DOI: 10.1155/2016/3173564] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/26/2016] [Accepted: 10/12/2016] [Indexed: 11/24/2022]
Abstract
Stroke is a leading cause of death and neurological disability worldwide and striatal ischemic stroke is frequent in humans due to obstruction of middle cerebral artery. Several pathological events underlie damage progression and a comprehensive description of the pathological features following experimental stroke in both acute and chronic survival times is a necessary step for further functional studies. Here, we explored the patterns of microglial activation, astrocytosis, oligodendrocyte damage, myelin impairment, and Nogo-A immunoreactivity between 3 and 30 postlesion days (PLDs) after experimental striatal stroke in adult rats induced by microinjections of endothelin-1 (ET-1). The focal ischemia induced tissue loss concomitant with intense microglia activation between 3 and 14 PLDs (maximum at 7 PLDs), decreasing afterward. Astrocytosis was maximum around 7 PLDs. Oligodendrocyte damage and Nogo-A upregulation were higher at 3 PLDs. Myelin impairment was maximum between 7 and 14 PLDs. Nogo-A expression was higher in the first week in comparison to control. The results add important histopathological features of ET-1 induced stroke in subacute and chronic survival times. In addition, the establishment of the temporal evolution of these neuropathological events is an important step for future studies seeking suitable neuroprotective drugs targeting neuroinflammation and white matter damage.
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Shanbhag NC, Henning RH, Schilling L. Long-term survival in permanent middle cerebral artery occlusion: a model of malignant stroke in rats. Sci Rep 2016; 6:28401. [PMID: 27329690 PMCID: PMC4916503 DOI: 10.1038/srep28401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 06/01/2016] [Indexed: 12/29/2022] Open
Abstract
Occlusion of the middle cerebral artery (MCA) by an intraluminal filament is widely used to study focal brain ischemia in male Sprague-Dawley rats. However, permanent occlusion goes along with a high fatality. To overcome this drawback we designed a new filament carrying a bowling pin-shaped tip (BP-tip) and compared this with three conventionally tipped filaments. Follow-up periods were 24 h (all groups) and 72 and 120 h in BP-tip group. Ischemic damage and swelling were quantified using silver nitrate staining. Collateral flow via the posterior cerebral artery (PCA) was assessed using selective dye perfusion of the internal carotid artery. Despite a comparable decrease of brain perfusion in all groups, ischemic damage was significantly smaller in BP-tips (p < 0.05). Moreover, BP-tip significantly reduced mortality from 60% to 12.5% and widely spared the occipital region and hypothalamus from ischemic damage. Conventional but not BP-tip filaments induced vascular distortion, measured as gross displacement of the MCA origin, which correlated with occipital infarction size. Accordingly, BP-tip occluded rats showed a significantly better collateral filling of the PCA territory. Ischemic volume significantly increased in BP-tip occlusion at 72 h follow-up. BP-tip filaments offer superior survival in permanent MCA occlusion, while mimicking the course of a malignant stroke in patients.
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Affiliation(s)
- Nagesh C Shanbhag
- Division of Neurosurgical Research, Medical Faculty Mannheim, Heidelberg University, Mannheim, D-68167, Germany.,Department of Clinical Pharmacy &Pharmacology, University Medical Center Groningen, University of Groningen, 9700 RB, The Netherlands
| | - Robert H Henning
- Department of Clinical Pharmacy &Pharmacology, University Medical Center Groningen, University of Groningen, 9700 RB, The Netherlands
| | - Lothar Schilling
- Division of Neurosurgical Research, Medical Faculty Mannheim, Heidelberg University, Mannheim, D-68167, Germany
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Klahr AC, Nadeau CA, Colbourne F. Temperature Control in Rodent Neuroprotection Studies: Methods and Challenges. Ther Hypothermia Temp Manag 2016; 7:42-49. [PMID: 27327871 DOI: 10.1089/ther.2016.0018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Extensive animal research facilitated the clinical translation of therapeutic hypothermia for cardiac arrest in adults and hypoxic-ischemic injury in infants. Similarly, clinical interest in hypothermia for other brain injuries, such as stroke, has been greatly supported by positive findings in preclinical work. The reliability, validity, and utility of animal models, among many research practices (blinding, randomization, etc.), are key to successful clinical translation. Here, we review methods used to induce and maintain hypothermia in animal models. These include physical and pharmacological methods. We emphasize the advantages and limitations of each approach, and the importance of using clinically relevant cooling protocols and appropriate monitoring and reporting approaches. Moreover, we performed a literature survey of ischemic stroke studies published in 2015 to highlight the continuing risk of temperature confounds in neuroprotection studies. For example, many still do not accurately monitor and report temperature during surgery (23.5%), even though almost half of these studies (46.0%) use pharmaceutical agents that likely influence temperature. We hope this review stimulates awareness and discussion of the importance of temperature in neuroprotective studies.
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Affiliation(s)
- Ana C Klahr
- 1 Neuroscience and Mental Health Institute, University of Alberta , Edmonton, Canada
| | - Colby A Nadeau
- 2 Department of Psychology, University of Alberta , Edmonton, Canada
| | - Frederick Colbourne
- 1 Neuroscience and Mental Health Institute, University of Alberta , Edmonton, Canada .,2 Department of Psychology, University of Alberta , Edmonton, Canada
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Peri-infarct depolarizations during focal ischemia in the awake Spontaneously Hypertensive Rat. Minimizing anesthesia confounds in experimental stroke. Neuroscience 2016; 325:142-52. [PMID: 27026594 DOI: 10.1016/j.neuroscience.2016.03.049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/02/2016] [Accepted: 03/21/2016] [Indexed: 11/22/2022]
Abstract
Anesthesia profoundly impacts peri-infarct depolarizations (PIDs), but only one prior report has described their monitoring during experimental stroke in awake animals. Since temporal patterns of PID occurrence are model specific, the current study examined PID incidence during focal ischemia in the awake Spontaneously Hypertensive Rat (SHR), and documented the impact of both prior and concurrent isoflurane anesthesia. For awake recordings, electrodes were implanted under isoflurane anesthesia 1day to 5weeks prior to occlusion surgery. Rats were then subjected to permanent or transient (2h) tandem occlusion of the middle cerebral and ipsilateral common carotid arteries, followed by PID monitoring for up to 3days. Comparison perfusion imaging studies evaluated PID-associated hyperemic transients during permanent ischemia under anesthesia at varied intervals following prior isoflurane exposure. Prior anesthesia attenuated PID number at intervals up to 1week, establishing 2weeks as a practical recovery duration following surgical preparation to avoid isoflurane preconditioning effects. PIDs in awake SHR were limited to the first 4h after permanent occlusions. Maintaining anesthesia during this interval reduced PID number, and prolonged their occurrence through several hours following anesthesia termination. Although PID number otherwise correlated with infarct size, PID suppression by anesthesia was not protective in the absence of reperfusion. PIDs persisted up to 36h after transient occlusions. These results differ markedly from the one previous report of such monitoring in awake Sprague-Dawley rats, which found an extended biphasic PID time course during 24h after both permanent and transient filament occlusions. PID occurrence closely reflects the time course of infarct progression in the respective models, and may be more useful than absolute PID number as an index of ongoing pathology.
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Jolkkonen J, Kwakkel G. Translational Hurdles in Stroke Recovery Studies. Transl Stroke Res 2016; 7:331-42. [PMID: 27000881 DOI: 10.1007/s12975-016-0461-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 02/11/2016] [Accepted: 03/09/2016] [Indexed: 12/20/2022]
Abstract
Emerging understanding of brain plasticity has opened new avenues for the treatment of stroke. The promising preclinical evidence with neuroprotective drugs has not been confirmed in clinical trials, thus nowadays, researchers, pharmaceutical companies, and funding bodies hesitate to initiate these expensive trials with restorative therapies. Since many of the previous failures can be traced to low study quality, a number of guidelines such as STAIR and STEPS were introduced to rectify these shortcomings. However, these guidelines stem from the study design for neuroprotective drugs and one may question whether they are appropriate for restorative approaches, which rely heavily on behavioral testing. Most of the recovery studies conducted in stroke patients have been small-scale, proof-of-concept trials. Consequently, the overall effect sizes of pooled phase II trials have proved unreliable and unstable in most meta-analyses. Although the methodological quality of trials in humans is improving, most studies still suffer from methodological flaws and do not meet even the minimum of evidence-based standards for reporting randomized controlled trials. The power problem of most phase II trials is mostly attributable to a lack of proper stratification with robust prognostic factors at baseline as well as the incorrect assumption that all patients will exhibit the same proportional amount of spontaneous neurological recovery poststroke. In addition, most trials suffer from insufficient treatment contrasts between the experimental and control arm and the outcomes have not been sufficiently responsive to detect small but clinically relevant changes in neurological impairments and activities. This narrative review describes the main factors that bias recovery studies, both in experimental animals and stroke patients.
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Affiliation(s)
- Jukka Jolkkonen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland. .,Neurocenter, Neurology, University Hospital of Kuopio, Kuopio, Finland.
| | - Gert Kwakkel
- Department of Rehabilitation Medicine, VU University Medical Center, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands.,Neurorehabilitation, Amsterdam Rehabilitation Research Center, Reade, Amsterdam, The Netherlands.,Neuroscience Campus Amsterdam, VU University Amsterdam, Amsterdam, The Netherlands.,Department of Physical Therapy and Human Movement Sciences, Northwestern University, Evanston, IL, USA
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DeBow SB, Clark DL, MacLellan CL, Colbourne F. Incomplete Assessment of Experimental Cytoprotectants in Rodent Ischemia Studies. Can J Neurol Sci 2014; 30:368-74. [PMID: 14672270 DOI: 10.1017/s0317167100003097] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Background:Inadequate preclinical testing (e.g., rodent studies) has been partly blamed for the failure of many cytoprotectants to effectively treat stroke in humans. For example, some drugs went to clinical trial without rigorous functional and histological assessment over long survival times. In this study, we characterized recent experimental practices in rodent cytoprotection experiments to determine whether the limitations of early studies have been rectified.Methods:We identified 138 rodent cytoprotection studies published in several leading journals (Journal of Neuroscience, Stroke, Journal of Cerebral Blood Flow and Metabolism and Experimental Neurology) for 2000 - 2002 and compared these to those published in 1990. From each study we determined the ischemia model, age and sex of the animal, the histological and functional endpoints used, and the methodology used to assess intra- and postischemic temperature.Results:Ninety-eight percent of recent studies used young adult rodents and most used males. Most studies (60%) did not assess functional outcome and survival times were often ≤ 48 hr (66%) for focal ischemia and ≤ 7 days (80%) for global ischemia. Over 60% of the experiments relied solely upon rectal temperature during ischemia and only 32.6% of ischemia studies measured temperature after surgery. The 1990 data were similar.Conclusion:Many investigators ignore the need to assess long-term functional and histological outcome and do not accurately represent clinical conditions of ischemia (e.g., use of aged animals). In addition, intra- and postischemic temperature measurement and control is frequently neglected or inadequately performed. Further clinical failures are likely.
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Affiliation(s)
- Suzanne B DeBow
- Department of Psychology, Center for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
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Nunes RR, Duval Neto GF, Garcia de Alencar JC, Franco SB, de Andrade NQ, Holanda Dumaresq DM, Cavalcante SL. Anesthetics, cerebral protection and preconditioning. Rev Bras Anestesiol 2014; 63:119-28. [PMID: 23438807 DOI: 10.1016/s0034-7094(13)70204-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 06/16/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents. CONTENT Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use. CONCLUSIONS The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.
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Surgery-related thrombosis critically affects the brain infarct volume in mice following transient middle cerebral artery occlusion. PLoS One 2013; 8:e75561. [PMID: 24086572 PMCID: PMC3782513 DOI: 10.1371/journal.pone.0075561] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 08/15/2013] [Indexed: 01/07/2023] Open
Abstract
Transient middle cerebral artery occlusion (tMCAO) model is widely used to mimic human focal ischemic stroke in order to study ischemia/reperfusion brain injury in rodents. In tMCAO model, intraluminal suture technique is widely used to achieve ischemia and reperfusion. However, variation of infarct volume in this model often requires large sample size, which hinders the progress of preclinical research. Our previous study demonstrated that infarct volume was related to the success of reperfusion although the reason remained unclear. The aim of present study is to explore the relationship between focal thrombus formation and model reproducibility with respect to infarct volume. We hypothesize that suture-induced thrombosis causes infarct volume variability due to insufficient reperfusion after suture withdrawal. Seventy-two adult male CD-1 mice underwent 90 minutes of tMCAO with or without intraperitoneal administration of heparin. Dynamic synchrotron radiation microangiography (SRA) and laser speckle contrast imaging (LSCI) were performed before and after tMCAO to observe the cerebral vascular morphology and to measure the cerebral blood flow in vivo. Infarct volume and neurological score were examined to evaluate severity of ischemic brain injury. We found that the rate of successful reperfusion was much higher in heparin-treated mice compared to that in heparin-free mice according to the result of SRA and LSCI at 1 and 3 hours after suture withdrawal (p<0.05). Pathological features and SRA revealed that thrombus formed in the internal carotid artery, middle cerebral artery or anterior cerebral artery, which blocked reperfusion following tMCAO. LSCI showed that cortical collateral circulation could be disturbed by thrombi. Our results demonstrated that suture-induced thrombosis was a critical element, which affects the success of reperfusion. Appropriate heparin management provides a useful approach for improving reproducibility of reperfusion model in mice.
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Zhu S, Li Y, Lu H, Li H, Tong S. Imaging the early cerebral blood flow changes in rat middle cerebral artery occlusion stroke model. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2012:2655-8. [PMID: 23366471 DOI: 10.1109/embc.2012.6346510] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Intraluminal middle cerebral artery occlusion (MCAO) model in rats has been widely used to mimic human ischemic stroke and serves as an indispensable tool in the stroke research field. One limitation of this model is its high variability in infarct volume. The cerebral blood flow (CBF) information after cerebrovascular occlusion may reflect the availability of collateral circulation, which serves as a key factor for brain infarct volume. Laser speckle contrast imaging (LSCI) is a valuable tool for full-field imaging of CBF with high spatial and temporal resolution. In this paper, we investigated the spatio-temporal changes of CBF in rat MCAO stroke model using our self-developed real-time LSCI system. CBF images of adult male Sprague Dawley rats (n=13) were recorded before surgery, during first 1.5 hours after surgery, and 24 hours after stroke. We compared the CBF changes of different functional vessels during this period. In the ipsilateral hemisphere, CBF of veins and arteries both decreased as expected, while CBF of veins increased after occlusion in the contralateral hemisphere. Moreover, we found a linear correlation between early-stage CBF after occlusion and brain infarct volume, which can be utilized for surgery guidance to improve the uniformity of rat MCAO stroke models.
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Affiliation(s)
- Shuping Zhu
- School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, Shanghai 200030, PR China
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19
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Nunes RR, Duval Neto GF, de Alencar JCG, Franco SB, de Andrade NQ, Dumaresq DMH, Cavalcante SL. Anesthetics, cerebral protection and preconditioning. Braz J Anesthesiol 2013; 63:119-28. [PMID: 24565096 DOI: 10.1016/j.bjane.2012.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 06/16/2012] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents. CONTENT Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use. CONCLUSIONS The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.
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Affiliation(s)
- Rogean Rodrigues Nunes
- TSA; MSc and PhD in Anesthetics; Postgraduate in Cardiology, Universidade Federal do Ceará (UFC); Jointly Responsible for the Center for Teaching and Training (CET) of Hospital Geral de Fortaleza (HGF); Medicine Professor of Fachristus; Postgraduate in Clinical Engineering, Universidade de Fortaleza (Unifor); Vice-Chair of the Research Ethics Committee, Hospital São Carlos, Fortaleza, Ceará.
| | | | | | | | | | - Danielle Maia Holanda Dumaresq
- TSA; MSc, UFC; Responsible for CET-IJF; Chairman of the Pediatric Anesthesia Committee, Sociedade Brasileira de Anestesiologia (SBA) - 2011; Medicine Professor of Fachristus, Fortaleza, Ceará
| | - Sara Lúcia Cavalcante
- PhD; Professor, Faculdade de Medicina, UFC; Corresponsible for the CET of the HGF from Hospital São Carlos, Fortaleza Ceara, Brazil
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PI3K/Akt Pathway Contributes to Neurovascular Unit Protection of Xiao-Xu-Ming Decoction against Focal Cerebral Ischemia and Reperfusion Injury in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:459467. [PMID: 23781261 PMCID: PMC3678438 DOI: 10.1155/2013/459467] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/31/2013] [Accepted: 04/09/2013] [Indexed: 11/18/2022]
Abstract
In the present study, we used a focal cerebral ischemia and reperfusion rat model to investigate the protective effects of Xiao-Xu-Ming decoction (XXMD) on neurovascular unit and to examine the role of PI3K (phosphatidylinositol 3-kinase)/Akt pathway in this protection. The cerebral ischemia was induced by 90 min of middle cerebral artery occlusion. Cerebral infarct area was measured by tetrazolium staining, and neurological function was observed at 24 h after reperfusion. DNA fragmentation assay, combined with immunofluorescence, was performed to evaluate apoptosis of neuron, astrocyte, and vascular endothelial cell which constitute neurovascular unit. The expression levels of proteins involved in PI3K/Akt pathway were detected by Western blot. The results showed that XXMD improved neurological function, decreased cerebral infarct area and neuronal damage, and attenuated cellular apoptosis in neurovascular unit, while these effects were abolished by inhibition of PI3K/Akt with LY294002. We also found that XXMD upregulated p-PDKl, p-Akt, and p-GSK3 β expression levels, which were partly reversed by LY294002. In addition, the increases of p-PTEN and p-c-Raf expression levels on which LY294002 had no effect were also observed in response to XXMD treatment. The data indicated the protective effects of XXMD on neurovascular unit partly through the activation of PI3K/Akt pathway.
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Malek M, Duszczyk M, Zyszkowski M, Ziembowicz A, Salinska E. Hyperbaric oxygen and hyperbaric air treatment result in comparable neuronal death reduction and improved behavioral outcome after transient forebrain ischemia in the gerbil. Exp Brain Res 2012; 224:1-14. [PMID: 23283415 PMCID: PMC3535395 DOI: 10.1007/s00221-012-3283-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 09/19/2012] [Indexed: 12/20/2022]
Abstract
Anoxic brain injury resulting from cardiac arrest is responsible for approximately two-thirds of deaths. Recent evidence suggests that increased oxygen delivered to the brain after cardiac arrest may be an important factor in preventing neuronal damage, resulting in an interest in hyperbaric oxygen (HBO) therapy. Interestingly, increased oxygen supply may be also reached by application of normobaric oxygen (NBO) or hyperbaric air (HBA). However, previous research also showed that the beneficial effect of hyperbaric treatment may not directly result from increased oxygen supply, leading to the conclusion that the mechanism of hyperbaric prevention of brain damage is not well understood. The aim of our study was to compare the effects of HBO, HBA and NBO treatment on gerbil brain condition after transient forebrain ischemia, serving as a model of cardiac arrest. Thereby, we investigated the effects of repetitive HBO, HBA and NBO treatment on hippocampal CA1 neuronal survival, brain temperature and gerbils behavior (the nest building), depending on the time of initiation of the therapy (1, 3 and 6 h after ischemia). HBO and HBA applied 1, 3 and 6 h after ischemia significantly increased neuronal survival and behavioral performance and abolished the ischemia-evoked brain temperature increase. NBO treatment was most effective when applied 1 h after ischemia; later application had a weak or no protective effect. The results show that HBO and HBA applied between 1 and 6 h after ischemia prevent ischemia-evoked neuronal damage, which may be due to the inhibition of brain temperature increase, as a result of the applied rise in ambient pressure, and just not due to the oxygen per se. This perspective is supported by the finding that NBO treatment was less effective than HBO or HBA therapy. The results presented in this paper may pave the way for future experimental studies dealing with pressure and temperature regulation.
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Affiliation(s)
- Michal Malek
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106 Warsaw, Poland
| | - Malgorzata Duszczyk
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106 Warsaw, Poland
| | - Marcin Zyszkowski
- Department of Anesthesiology and Intensive Care, Military Institute of Medicine, Warsaw, Poland
| | - Apolonia Ziembowicz
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106 Warsaw, Poland
| | - Elzbieta Salinska
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106 Warsaw, Poland
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Ectopic ependymal cells in striatum accompany neurogenesis in a rat model of stroke. Neuroscience 2012; 214:159-70. [DOI: 10.1016/j.neuroscience.2012.03.062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/29/2012] [Accepted: 03/20/2012] [Indexed: 11/17/2022]
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Crumrine RC, Marder VJ, Taylor GM, LaManna JC, Tsipis CP, Novokhatny V, Scuderi P, Petteway SR, Arora V. Safety evaluation of a recombinant plasmin derivative lacking kringles 2-5 and rt-PA in a rat model of transient ischemic stroke. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2012; 4:10. [PMID: 22591588 PMCID: PMC3464715 DOI: 10.1186/2040-7378-4-10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 04/28/2012] [Indexed: 05/31/2023]
Abstract
BACKGROUND Tissue type plasminogen activator is the only approved thrombolytic agent for the treatment of ischemic stroke. However, it carries the disadvantage of a 10-fold increase in symptomatic and asymptomatic intracranial hemorrhage. A safer thrombolytic agent may improve patient prognosis and increase patient participation in thrombolytic treatment. A novel direct-acting thrombolytic agent, Δ(K2-K5) plasmin, promising an improved safety profile was examined for safety in the snare ligature model of stroke in the rat. METHODS Male spontaneously hypertensive rats were subjected to 6 hours middle cerebral artery occlusion followed by 18 hours reflow. Beginning 1 minute before reflow, they were dosed with saline, vehicle, Δ(K2-K5) plasmin (0.15, 0.5, 1.5, and 5 mg/kg) or recombinant tissue-type plasminogen activator (10 and 30 mg/kg) by local intra-arterial infusion lasting 10 to 60 minutes. The rats were assessed for bleeding score, infarct volume, modified Bederson score and general behavioral score. In a parallel study, temporal progression of infarct volume was determined. In an in vitro study, whole blood clots from humans, canines and rats were exposed to Δ(K2-K5). Clot lysis was monitored by absorbance at 280 nm. RESULTS The main focus of this study was intracranial hemorrhage safety. Δ(K2-K5) plasmin treatment at the highest dose caused no more intracranial hemorrhage than the lowest dose of recombinant tissue type plasminogen activator, but showed at least a 5-fold superior safety margin. Secondary results include: temporal infarct volume progression shows that the greatest expansion of infarct volume occurs within 2-3 hours of middle cerebral artery occlusion in the spontaneously hypertensive rat. A spike in infarct volume was observed at 6 hours ischemia with reflow. Δ(K2-K5) plasmin tended to reduce infarct volume and improve behavior compared to controls. In vitro data suggests that Δ(K2-K5) plasmin is equally effective at lysing clots from humans, canines and rats. CONCLUSIONS The superior intracranial hemorrhage safety profile of the direct-acting thrombolytic Δ(K2-K5) plasmin compared with recombinant tissue type plasminogen activator makes this agent a good candidate for clinical evaluation in the treatment of acute ischemic stroke.
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Affiliation(s)
- R Christian Crumrine
- Research and Pre-clinical Development, Grifols Therapeutics, Inc., Research Triangle Park, North Carolina, USA
| | - Victor J Marder
- Division of Hematology/Medical Oncology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - G McLeod Taylor
- Research and Pre-clinical Development, Grifols Therapeutics, Inc., Research Triangle Park, North Carolina, USA
| | - Joseph C LaManna
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - Constantinos P Tsipis
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - Valery Novokhatny
- Research and Pre-clinical Development, Grifols Therapeutics, Inc., Research Triangle Park, North Carolina, USA
| | - Philip Scuderi
- Research and Pre-clinical Development, Grifols Therapeutics, Inc., Research Triangle Park, North Carolina, USA
| | - Stephen R Petteway
- Research and Pre-clinical Development, Grifols Therapeutics, Inc., Research Triangle Park, North Carolina, USA
| | - Vikram Arora
- Research and Pre-clinical Development, Grifols Therapeutics, Inc., Research Triangle Park, North Carolina, USA
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Campos F, Blanco M, Barral D, Agulla J, Ramos-Cabrer P, Castillo J. Influence of temperature on ischemic brain: Basic and clinical principles. Neurochem Int 2012; 60:495-505. [DOI: 10.1016/j.neuint.2012.02.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 01/31/2012] [Accepted: 02/04/2012] [Indexed: 12/24/2022]
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Crumrine RC, Marder VJ, Taylor GM, Lamanna JC, Tsipis CP, Scuderi P, Petteway SR, Arora V. Intra-arterial administration of recombinant tissue-type plasminogen activator (rt-PA) causes more intracranial bleeding than does intravenous rt-PA in a transient rat middle cerebral artery occlusion model. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2011; 3:10. [PMID: 21933438 PMCID: PMC3184064 DOI: 10.1186/2040-7378-3-10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 09/20/2011] [Indexed: 11/20/2023]
Abstract
Background Intra-arterial (IA) administration of rt-PA for ischemic stroke has the potential for greater thrombolytic efficacy, especially for a large thrombus in the M1 or M2 segment of the middle cerebral artery (MCA). Intracranial hemorrhage (ICH) is a concern with IA or intravenous (IV) administration especially as the therapeutic window is extended. However, because IA administration delivers a higher local concentration of agent, the incidence and severity of ICH may be greater than with similar doses IV. We investigated the safety of rt-PA administration by IA compared to IV infusion following 6 hours of MCA occlusion (MCAo) with reflow in the spontaneously hypertensive rat (SHR). Methods Male SHRs were subjected to 6 hours MCAo with 18 hours reflow using a snare ligature model. They were treated with IA saline, IA rt-PA (1, 5, 10, 30 mg/kg), or IV rt-PA (10 and 30 mg/kg) by a 10 to 60 minute infusion beginning approximately 1 minute before reflow. The rats were recovered for 24 hours after MCAo onset at which time Bleeding Score, infarct volume, and Modified Bederson Score were measured. Results Greater hemorrhagic transformation occurred with 10 and 30 mg/kg rt-PA administered IA than IV. The IV 10 mg/kg rt-PA dosage induced significantly less bleeding than did the 1 or 5 mg/kg IA groups. No significant increase in infarct volume was observed after IA or IV treatment. Rats treated with 30 mg/kg rt-PA by either the IA or IV route had greater neurological dysfunction compared to all other groups. Conclusions Administration of rt-PA by the IA route following 6 hours of MCAo results in greater ICH and worse functional recovery than comparable dosages IV. Significantly greater bleeding was observed when the IA dose was a tenth of the IV dose. The increased bleeding did not translate in larger infarct volumes.
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Affiliation(s)
- R Christian Crumrine
- Research and Pre-clinical Development, Grifols Therapeutics, Inc,, Research Triangle Park, North Carolina, USA.
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Lipsanen A, Jolkkonen J. Experimental approaches to study functional recovery following cerebral ischemia. Cell Mol Life Sci 2011; 68:3007-17. [PMID: 21626271 PMCID: PMC11114796 DOI: 10.1007/s00018-011-0733-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 05/10/2011] [Accepted: 05/12/2011] [Indexed: 01/10/2023]
Abstract
Valid experimental models and behavioral tests are indispensable for the development of therapies for stroke. The translational failure with neuroprotective drugs has forced us to look for alternative approaches. Restorative therapies aiming to facilitate the recovery process by pharmacotherapy or cell-based therapy have emerged as promising options. Here we describe the most common stroke models used in cell-based therapy studies with particular emphasis on their inherent complications, which may affect behavioral outcome. Loss of body weight, stress, hyperthermia, immunodepression, and infections particularly after severe transient middle cerebral artery occlusion (filament model) are recognized as possible confounders to impair performance in certain behavioral tasks and bias the treatment effects. Inherent limitations of stroke models should be carefully considered when planning experiments to ensure translation of behavioral data to the clinic.
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Affiliation(s)
- Anu Lipsanen
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, Yliopistonranta 1C, FI-70210 Kuopio, Finland
- Brain Research and Rehabilitation Center Neuron, Kortejoki, FI-71130 Kuopio, Finland
| | - Jukka Jolkkonen
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, Yliopistonranta 1C, FI-70210 Kuopio, Finland
- Brain Research and Rehabilitation Center Neuron, Kortejoki, FI-71130 Kuopio, Finland
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Heldmann U, Mine Y, Kokaia Z, Ekdahl CT, Lindvall O. Selective depletion of Mac-1-expressing microglia in rat subventricular zone does not alter neurogenic response early after stroke. Exp Neurol 2011; 229:391-8. [DOI: 10.1016/j.expneurol.2011.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 03/02/2011] [Accepted: 03/07/2011] [Indexed: 12/11/2022]
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Affiliation(s)
- Dae-Yul Kim
- Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College Medicine, Korea
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Zhang H, Xu G, Zhang J, Murong S, Mei Y, Tong E. Mild hypothermia reduces ischemic neuron death via altering the expression of p53 and bcl-2. Neurol Res 2010; 32:384-9. [PMID: 20483005 DOI: 10.1179/016164110x12670144526228] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Studies exploring roles of p53 and bcl-2 in neuroprotection by hypothermia in focal cerebral ischemia have not provided consistent results. In the present study, we determined whether p53 and bcl-2 are involved in the hypothermia-induced neuroprotection. METHODS Male Sprague-Dawley rats were divided into four groups: normothermic (37-38 degrees C) ischemia, hypothermic (31-32 degrees C) ischemia, hyperthermic (41-42 degrees C) ischemia and sham-operated group. Global cerebral ischemia was established for 20 minutes using the Pulsinelli four-vessel occlusion model and the brain temperature was maintained at defined levels for 60 minutes following the 20 min ischemia. The mortality in rats was evaluated at 72 hour and 168 hour reperfusion. The expression of p53 and bcl-2 proteins was detected at 24, 48 and 72 hours after reperfusion. At the same intervals, neuron necrosis and apoptosis in brain regions was also detected using hematoxylin and eosin (HE) staining and terminal deoxynucleotldyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL). RESULTS The mortalities of rats in normothemia, hypothermia and hyperthermia groups was 33.3, 16.7 and 50% at 72 hour reperfusion. At 168 hours of reperfusion, the mortality in the three groups was 58.3, 25 and 100%, respectively. In light microscopy studies, necrotic neurons and apoptotic neurons were found in the hippocampus after global cerebral ischemia. Surviving neurons in hippocampus was increased in mild hypothermic ischemia group (p<0.05) and decreased in hyperthermia ischemia group (p<0.01) at 24, 48 and 72 hour reperfusion. TUNEL-positive neurons in hippocampus decreased in hypothermic ischemia group (p<0.05 or p<0.01) and increased in hyperthermic ischemia group (p<0.01) at 24, 48 and 72 hour reperfusion. The expression of p53 and bcl-2 proteins was found in the neurons of cerebral cortex after global cerebral ischemia. P53 decreased and bcl-2 increased in hypothermia group. CONCLUSION Hypothermia reduces ischemic neuronal necrosis and apoptosis by reducing p53 and increasing bcl-2 expression. Hyperthermia accelerated ischemic neuronal injury by increasing p53 and reducing bcl-2 expression.
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Affiliation(s)
- Hong Zhang
- Department of Neurology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China.
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Kelsen J, Larsen MH, Sørensen JC, Møller A, Frøkiaer J, Nielsen S, Nyengaard JR, Mikkelsen JD, Rønn LCB. Neuronal precursor cell proliferation in the hippocampus after transient cerebral ischemia: a comparative study of two rat strains using stereological tools. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2010; 2:8. [PMID: 20370927 PMCID: PMC2868803 DOI: 10.1186/2040-7378-2-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2009] [Accepted: 04/06/2010] [Indexed: 01/19/2023]
Abstract
Background We are currently investigating microglial activation and neuronal precursor cell (NPC) proliferation after transient middle cerebral artery occlusion (tMCAo) in rats. This study aimed: (1) to investigate differences in hippocampal NPC proliferation in outbred male spontaneously hypertensive rats (SHRs) and Sprague-Dawley rats (SDs) one week after tMCAo; (2) to present the practical use of the optical fractionator and 2D nucleator in stereological brain tissue analyses; and (3) to report our experiences with an intraluminal tMCAo model where the occluding filament is advanced 22 mm beyond the carotid bifurcation and the common carotid artery is clamped during tMCAo. Methods Twenty-three SDs and twenty SHRs were randomized into four groups subjected to 90 minutes tMCAo or sham. BrdU (50 mg/kg) was administered intraperitoneally twice daily on Day 4 to 7 after surgery. On Day 8 all animals were euthanized. NeuN-stained tissue sections were used for brain and infarct volume estimation with the 2D nucleator and Cavalieri principle. Brains were studied for the presence of activated microglia (ED-1) and hippocampal BrdU incorporation using the optical fractionator. Results We found no significant difference or increase in post-ischemic NPC proliferation between the two strains. However, the response to remote ischemia may differ between SDs and SHRs. In three animals increased post-stroke NPC proliferation was associated with hippocampal ischemic injury. The mean infarct volume was 89.2 ± 76.1 mm3 in SHRs and 16.9 ± 22.7 mm3 in SDs (p < 0.005). Eight out of eleven SHRs had ischemic neocortical damage in contrast to only one out of 12 SDs. We observed involvement of the anterior choroidal and hypothalamic arteries in several animals from both strains and the anterior cerebral artery in two SHRs. Conclusions We found no evidence of an early hippocampal NPC proliferation one week after tMCAo in both strains. Infarction within the anterior choroidal artery could induce hippocampal ischemia and increase NPC proliferation profoundly. NPC proliferation was not aggravated by the presence of activated microglia. Intraluminal tMCAo in SHRs gave a more reliable infarct with neocortical involvement, but affected territories supplied by the anterior cerebral, anterior choroidal and hypothalamic arteries.
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Affiliation(s)
- Jesper Kelsen
- The Water and Salt Research Centre, University of Aarhus, DK-8000 Aarhus C, Denmark.
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Braeuninger S, Kleinschnitz C. Rodent models of focal cerebral ischemia: procedural pitfalls and translational problems. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2009; 1:8. [PMID: 20150986 PMCID: PMC2820446 DOI: 10.1186/2040-7378-1-8] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 11/25/2009] [Indexed: 11/10/2022]
Abstract
Rodent models of focal cerebral ischemia are essential tools in experimental stroke research. They have added tremendously to our understanding of injury mechanisms in stroke and have helped to identify potential therapeutic targets. A plethora of substances, however, in particular an overwhelming number of putative neuroprotective agents, have been shown to be effective in preclinical stroke research, but have failed in clinical trials. A lot of factors may have contributed to this failure of translation from bench to bedside. Often, deficits in the quality of experimental stroke research seem to be involved. In this article, we review the commonest rodent models of focal cerebral ischemia - middle cerebral artery occlusion, photothrombosis, and embolic stroke models - with their respective advantages and problems, and we address the issue of quality in preclinical stroke modeling as well as potential reasons for translational failure.
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Affiliation(s)
- Stefan Braeuninger
- Department of Neurology, Julius-Maximilians-Universitaet Wuerzburg, Josef-Schneider-Str. 11, 97080 Wuerzburg, Germany.
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32
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Sicard KM, Fisher M. Animal models of focal brain ischemia. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2009; 1:7. [PMID: 20150985 PMCID: PMC2820445 DOI: 10.1186/2040-7378-1-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Accepted: 11/13/2009] [Indexed: 11/25/2022]
Abstract
Stroke is a leading cause of disability and death in many countries. Understanding the pathophysiology of ischemic injury and developing therapies is an important endeavor that requires much additional research. Animal stroke models provide an important mechanism for these activities. A large number of stroke models have been developed and are currently used in laboratories around the world. These models are overviewed as are approaches for measuring infarct size and functional outcome.
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Affiliation(s)
- Kenneth M Sicard
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01453, USA
| | - Marc Fisher
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01453, USA
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Abstract
Hyperthermia frequently occurs in stroke patients. Hyperthermia negatively correlates with clinical outcome and adversely effects treatment regiments otherwise successful under normothermic conditions. Preclinical studies also demonstrate that hyperthermia converts salvageable penumbra to ischaemic infarct. The present article reviews the knowledge accumulated from both clinical and preclinical studies about hyperthermia and ischaemic brain injury, examines current treatment strategies and discusses future research directions.
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Affiliation(s)
- C. X. Wang
- The Central Illinois Neuroscience Foundation, Bloomington, IL, USA
| | - A. Stroink
- The Central Illinois Neuroscience Foundation, Bloomington, IL, USA
| | - J. M. Casto
- Department of Biological Science, Illinois State University, Normal, IL, USA
| | - K. Kattner
- The Central Illinois Neuroscience Foundation, Bloomington, IL, USA
- Department of Biological Science, Illinois State University, Normal, IL, USA
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Thored P, Heldmann U, Gomes-Leal W, Gisler R, Darsalia V, Taneera J, Nygren JM, Jacobsen SEW, Ekdahl CT, Kokaia Z, Lindvall O. Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke. Glia 2009; 57:835-49. [PMID: 19053043 DOI: 10.1002/glia.20810] [Citation(s) in RCA: 269] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Neural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increased numbers of activated microglia in ipsilateral SVZ concomitant with neuroblast migration into the striatum at 2, 6, and 16 weeks, with maximum at 6 weeks, following 2 h middle cerebral artery occlusion in rats. In the peri-infarct striatum, numbers of activated microglia peaked already at 2 weeks and declined thereafter. Microglia in SVZ were resident or originated from bone marrow, with maximum proliferation during the first 2 weeks postinsult. In SVZ, microglia exhibited ramified or intermediate morphology, signifying a downregulated inflammatory profile, whereas amoeboid or round phagocytic microglia were frequent in the peri-infarct striatum. Numbers of microglia expressing markers of antigen-presenting cells (MHC-II, CD86) increased in SVZ but very few lymphocytes were detected. Using quantitative PCR, strong short- and long-term increase (at 1 and 6 weeks postinfarct) of insulin-like growth factor-1 (IGF-1) gene expression was detected in SVZ tissue. Elevated numbers of IGF-1-expressing microglia were found in SVZ at 2, 6, and 16 weeks after stroke. At 16 weeks, 5% of microglia but no other cells in SVZ expressed the IGF-1 protein, which mitigates apoptosis and promotes proliferation and differentiation of NSCs. The long-term accumulation of microglia with proneurogenic phenotype in the SVZ implies a supportive role of these cells for the continuous neurogenesis after stroke.
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Affiliation(s)
- Pär Thored
- Laboratory of Neurogenesis and Cell Therapy, Section of Restorative Neurology, Wallenberg Neuroscience Center A11, University Hospital, Lund, Sweden
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Effects of progesterone administration on infarct volume and functional deficits following permanent focal cerebral ischemia in rats. Brain Res 2008; 1257:94-101. [PMID: 19135987 DOI: 10.1016/j.brainres.2008.12.048] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 12/10/2008] [Accepted: 12/12/2008] [Indexed: 11/21/2022]
Abstract
Recent experimental evidence indicates that progesterone (PROG) protects against various models of brain injury, including ischemic stroke. Most human studies of pharmacologic treatments for acute cerebral stroke have failed despite initial success in animal models. To simulate better the typical human stroke without reperfusion, the present study was conducted to examine the efficacy of PROG on infarct volume and functional outcome in a permanent model of stroke, using direct cauterization of the middle cerebral artery (MCA). Twenty-four male adult Sprague-Dawley rats underwent pMCAO by electro-coagulation and sham operation. After induction of permanent MCA occlusion (pMCAO), the rats received an initial intraperitoneal injection of PROG (8 mg/kg) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 24 and 48 h. Functional deficits were tested on the rotarod and grip-strength meter at 24, 48 and 72 h after pMCAO. The rats were killed 72 h after surgery and isolated brain was sectioned into coronal slices and stained with 2, 3, 5-triphenyltetrazolium chloride (TTC). PROG-treated rats showed a substantial reduction (54.05%) in the volume of the infarct (% contralateral hemisphere) compared to vehicle controls. In addition there was a significant improvement in ability to remain on an accelerating rotarod and increased grip strength observed in the pMCAO rats treated with PROG compared to vehicle. Taken together, these data indicate that PROG is beneficial in one of the best-characterized models of stroke, and may warrant further testing in future clinical trials for human stroke.
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Nagel S, Papadakis M, Hoyte L, Buchan AM. Therapeutic hypothermia in experimental models of focal and global cerebral ischemia and intracerebral hemorrhage. Expert Rev Neurother 2008; 8:1255-68. [PMID: 18671669 DOI: 10.1586/14737175.8.8.1255] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Experimental evidence shows that therapeutic hypothermia (TH) protects the brain from cerebral injury in multiple ways. In different models of focal and global cerebral ischemia, mild-to-moderate hypothermia reduces mortality and neuronal injury and improves neurological outcome. In models of experimental intracerebral hemorrhage (ICH), TH reduces edema formation but does not show consistent benefi cial effects on functional outcome parameters. However, the number of studies of hypothermia on ICH is still limited. TH is most effective when applied before or during the ischemic event, and its neuroprotective properties vary according to species, strains and the model of ischemia used. Intrinsic changes in body and brain temperature frequently occur in experimental models of focal and global cerebral ischemia, and may have infl uenced studies on other neuroprotectants. This might be one explanation for the failure of a large amount of translational clinical neuroprotective trials. Hypothermia is the only neuroprotective therapeutic agent for cerebral ischemia that has successfully managed the transfer from bench to bedside, and it is an approved therapy for patients after cardiac arrest and children with hypoxic-ischemic encephalopathy. However, the implementation of hypothermia in the treatment of stroke patients is still far from routine clinical practice. In this article, the authors describe the development of TH in different models of focal and global cerebral ischemia, point out why hypothermia is so efficient in experimental cerebral ischemia, explain why temperature regulation is essential for further neuroprotective studies and discuss why TH for acute ischemic stroke still remains a promising but controversial therapeutic option.
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Affiliation(s)
- Simon Nagel
- Acute Stroke Programme, Nuffield Department of Clinical Medicine, John Radcliffe Hospital, Oxford, OX3 9DU, UK.
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Maddahi A, Edvinsson L. Enhanced expressions of microvascular smooth muscle receptors after focal cerebral ischemia occur via the MAPK MEK/ERK pathway. BMC Neurosci 2008; 9:85. [PMID: 18793415 PMCID: PMC2553085 DOI: 10.1186/1471-2202-9-85] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 09/15/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND MEK1/2 is a serine/threonine protein that phosphorylates extracellular signal-regulated kinase (ERK1/2). Cerebral ischemia results in enhanced expression of cerebrovascular contractile receptors in the middle cerebral artery (MCA) leading to the ischemic region. Here we explored the role of the MEK/ERK pathway in receptor expression following ischemic brain injury using the specific MEK1 inhibitor U0126. METHODS AND RESULT Rats were subjected to a 2-h middle cerebral artery occlusion (MCAO) followed by reperfusion for 48-h and the ischemic area was calculated. The expression of phosphorylated ERK1/2 and Elk-1, and of endothelin ETA and ETB, angiotensin AT1, and 5-hydroxytryptamine 5-HT1B receptors were analyzed with immunohistochemistry using confocal microscopy in cerebral arteries, microvessels and in brain tissue. The expression of endothelin ETB receptor was analyzed by quantitative Western blot. We demonstrate that there is an increase in the number of contractile smooth muscle receptors in the MCA and in micro- vessels within the ischemic region. The enhanced expression occurs in the smooth muscle cells as verified by co-localization studies. This receptor upregulation is furthermore associated with enhanced expression of pERK1/2 and of transcription factor pElk-1 in the vascular smooth muscle cells. Blockade of transcription with the MEK1 inhibitor U0126, given at the onset of reperfusion or as late as 6 hours after the insult, reduced transcription (pERK1/2 and pElk-1), the enhanced vascular receptor expression, and attenuated the cerebral infarct and improved neurology score. CONCLUSION Our results show that MCAO results in upregulation of cerebrovascular ETB, AT1 and 5-HT1B receptors. Blockade of this event with a MEK1 inhibitor as late as 6 h after the insult reduced the enhanced vascular receptor expression and the associated cerebral infarction.
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Affiliation(s)
- Aida Maddahi
- Division of Experimental Vascular Research, BMC A13, Lund University, 221 84 Lund, Sweden.
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38
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Hossmann KA. Cerebral ischemia: Models, methods and outcomes. Neuropharmacology 2008; 55:257-70. [DOI: 10.1016/j.neuropharm.2007.12.004] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 12/06/2007] [Accepted: 12/10/2007] [Indexed: 01/31/2023]
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Braithwaite SP, Xu J, Leung J, Urfer R, Nikolich K, Oksenberg D, Lombroso PJ, Shamloo M. Expression and function of striatal enriched protein tyrosine phosphatase is profoundly altered in cerebral ischemia. Eur J Neurosci 2008; 27:2444-52. [PMID: 18445231 DOI: 10.1111/j.1460-9568.2008.06209.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Striatal enriched protein tyrosine phosphatase (STEP) acts in the central nervous system to dephosphorylate a number of important proteins involved in synaptic function including ERK and NMDA receptor subunits. These proteins are also linked to stroke, in which cerebral ischemia triggers a complex cascade of events. Here we demonstrate that STEP is regulated at both the transcriptional and the post-transcriptional levels in rat models of cerebral ischemia and that its regulation may play a role in the outcome of ischemic insults. After transient middle cerebral artery occlusion, there are profound decreases in the levels of STEP mRNA, whilst in global ischemia STEP mRNA is selectively down-regulated in areas susceptible to ischemic damage. In a neuroprotective preconditioning paradigm, and in regions of the brain that are relatively resistant to ischemic damage, STEP mRNA levels are increased. Furthermore, there is a significant processing of STEP after ischemia to generate a novel species, STEP(33), resulting in a redistribution of STEP from membrane-bound to soluble compartments. Concomitant with the cleavage of mature forms of STEP, there are changes in the phosphorylation state of ERK. We show that the cleavage of STEP leads to a catalytically active form, but this cleaved form no longer binds to and dephosphorylates its substrate pERK. Therefore, in response to ischemic insults, there are profound reductions in both the amount and the activity of STEP, its localization, as well as the activity of one of its key substrates, pERK. These changes in STEP may reflect a critical role in the outcomes of ischemic brain injury.
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Souza-Rodrigues R, Costa A, Lima R, Dos Santos C, Picanço-Diniz C, Gomes-Leal W. Inflammatory response and white matter damage after microinjections of endothelin-1 into the rat striatum. Brain Res 2008; 1200:78-88. [DOI: 10.1016/j.brainres.2007.11.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2007] [Revised: 11/07/2007] [Accepted: 11/08/2007] [Indexed: 01/23/2023]
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Thored P, Wood J, Arvidsson A, Cammenga J, Kokaia Z, Lindvall O. Long-term neuroblast migration along blood vessels in an area with transient angiogenesis and increased vascularization after stroke. Stroke 2007; 38:3032-9. [PMID: 17901386 DOI: 10.1161/strokeaha.107.488445] [Citation(s) in RCA: 296] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Stroke induced by middle cerebral artery occlusion (MCAO) causes long-term formation of new striatal neurons from stem/progenitor cells in the subventricular zone (SVZ). We explored whether MCAO leads to hypoxia, changes in vessel density, and angiogenesis in the ipsilateral SVZ and adjacent striatum, and determined the relation between the migrating neuroblasts and the vasculature. METHODS Adult rats were subjected to 2 hours of MCAO. Hypoxia was studied by injecting Hypoxyprobe-1 during MCAO or 6 weeks later. Vessel density and length was estimated using stereology. New cells were labeled with 5'-bromo-2'deoxyuridine (BrdU) during weeks 1 and 2 or 7 and 8 after MCAO, and angiogenesis was assessed immunohistochemically with antibodies against BrdU and endothelial cell markers. Distance from neuroblasts to nearest vessel was measured using confocal microscopy. RESULTS The ischemic insult caused transient hypoxia and early, low-grade angiogenesis, but no damage or increase of vascular density in the SVZ. Angiogenesis was detected during the first 2 weeks in the dorsomedial striatum adjacent to the SVZ, which also showed long-lasting increase of vascularization. At 2, 6, and 16 weeks after MCAO, the majority of neuroblasts migrated through this area toward the damage, closely associated with blood vessels. CONCLUSIONS The vasculature plays an important role for long-term striatal neurogenesis after stroke. During several months, neuroblasts migrate close to blood vessels through an area exhibiting early vascular remodeling and persistently increased vessel density. Optimizing vascularization should be an important strategy to promote neurogenesis and repair after stroke.
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Affiliation(s)
- Pär Thored
- Laboratory of Neurogenesis and Cell Therapy, Section of Restorative Neurology, Wallenberg Neuroscience Center, University Hospital, SE-221 84 Lund, Sweden
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Hiraga N, Adachi N, Liu K, Nagaro T, Arai T. Suppression of inflammatory cell recruitment by histamine receptor stimulation in ischemic rat brains. Eur J Pharmacol 2007; 557:236-44. [PMID: 17169356 DOI: 10.1016/j.ejphar.2006.11.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2006] [Revised: 11/06/2006] [Accepted: 11/08/2006] [Indexed: 10/23/2022]
Abstract
Inflammation is a crucial factor in the development of ischemia-induced brain injury. Since facilitation of central histaminergic activity ameliorates reperfusion injury, effects of postischemic administration of L-histidine, a precursor of histamine, and thioperamide, a histamine H3 receptor antagonist, on inflammatory cell infiltration were evaluated in a rat model of transient occlusion of the middle cerebral artery. After reperfusion for 12, 24, or 72 h following 2 h of occlusion, brain slices were immunohistochemically stained with antibodies against myeloperoxidase and CD68, which were markers of polymorphonuclear leukocytes and macrophages/microglia, respectively. After reperfusion for 12-24 h, the number of neutrophils on the ischemic side increased markedly, whereas the increase was not observed on the contralateral side. Administration of L-histidine (1000 mg/kg x 2, i.p.), immediately and 6 h after reperfusion, reduced the number of neutrophils to 52%. Simultaneous administration of thioperamide (5 mg/kg, s.c.) further decreased the number of neutrophils to 32%. Likewise, the ischemia induced increase in the number of CD68-positive cells after 24 h was suppressed by L-histidine injections. The L-histidine administration decreased the number of CD4+ T lymphocytes on both ischemic and contralateral sides after 12 h, and concurrent administration of thioperamide prolonged the effect. Although administration of mepyramine (3 nmol, i.c.v.) did not affect suppression of leukocyte infiltration, ranitidine tended to reverse the effect of L-histidine. These data suggest that enhancement of central histaminergic activity suppresses inflammatory cell recruitment after ischemic events through histamine H2 receptors, which may be a mechanism underlying the protective effect of L-histidine.
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Affiliation(s)
- Norihito Hiraga
- Department of Anesthesiology and Resuscitology, Ehime University Graduate School of Medicine, Shitsukawa, Touon-shi, Ehime 791-0295, Japan.
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Whitehead SN, Bayona NA, Cheng G, Allen GV, Hachinski VC, Cechetto DF. Effects of Triflusal and Aspirin in a Rat Model of Cerebral Ischemia. Stroke 2007; 38:381-7. [PMID: 17194886 DOI: 10.1161/01.str.0000254464.05561.72] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background and Purpose—
Neuroinflammation plays a critical role in the pathogenesis of cerebral ischemia. Triflusal, a selective cyclooxygenase-2, and its active metabolite 3-hydroxy-4-trifluoromethylbenzoic acid may inhibit apoptosis and inflammation after cerebral ischemia. An in vivo model of cerebral ischemia was used to investigate the effects of triflusal and aspirin treatment on infarct volume, and inflammation after cerebral ischemia in the rat.
Methods—
Male Wistar rats were subjected to a permanent right-sided middle cerebral artery occlusion. Rats received oral administration of either triflusal or aspirin. After 3 days after surgery, immunostaining was used to detect neuroinflammatory cells and molecules, and infarct volumes were measured.
Results—
Both triflusal and aspirin at a dose of 30 mg/kg but not 10 mg/kg significantly reduced infarct volume compared with vehicle treatment. Middle cerebral artery occlusion resulted in increased astrocyte and heat shock protein-27 (Hsp27) immunostaining in the ipsilateral cortex. Triflusal (30 mg/kg) or aspirin treatment (30 mg/kg) did not reduce the levels of GFAP or Hsp27 immunostaining. Triflusal (30 mg/kg) also significantly decreased the protein levels of IL-Iβ but not nuclear factor kappa B or tumor necrosis factor-α in the cortex ipsilateral to the middle cerebral artery occlusion.
Conclusions—
The results suggest that triflusal and aspirin appear to be equally neuroprotective against middle cerebral artery occlusion-induced cerebral ischemia. Therefore, strong rationale exists to continue the neuroprotective examination of triflusal in brain injury.
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Affiliation(s)
- Shawn N Whitehead
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Canada
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Shamloo M, Soriano L, von Schack D, Rickhag M, Chin DJ, Gonzalez-Zulueta M, Gido G, Urfer R, Wieloch T, Nikolich K. Npas4, a novel helix-loop-helix PAS domain protein, is regulated in response to cerebral ischemia. Eur J Neurosci 2007; 24:2705-20. [PMID: 17156197 DOI: 10.1111/j.1460-9568.2006.05172.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Basic helix-loop-helix PAS domain proteins form a growing family of transcription factors. These proteins are involved in the process of adaptation to cellular stresses and environmental factors such as a change in oxygen concentration. We describe the identification and characterization of a recently cloned PAS domain protein termed Npas4 in ischemic rat brain. Using gene expression profiling following middle cerebral artery occlusion, we showed that the Npas4 mRNA is differentially expressed in ischemic tissue. The full-length gene was cloned from rat brain and its spatial and temporal expression characterized with in situ hybridization and Northern blotting. The Npas4 mRNA is specifically expressed in the brain and is highly up-regulated in ischemic tissues following both focal and global cerebral ischemic insults. Immunohistochemistry revealed a strong expression in the limbic system and thalamus, as well as in layers 3 and 5 in the cortex of the unchallenged brain. When overexpressed in HEK 293 cells, Npas4 appears as a protein of approximately 100 kDa. In brain samples, however, in addition to the 100 kDa band a specific 200 kDa immunoreactive band was also detected. Ischemic challenge lead to a decrease in the 200 kDa form and a simultaneous increase in the 100 kDa immunoreactivity. This could indicate a novel regulatory mechanism for activation and/or deactivation of this protein in response to ischemic brain injury.
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Affiliation(s)
- Mehrdad Shamloo
- AGY Therapeutics, South San Francisco, California 94080, USA.
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Abstract
Hypothermia reduces cell death and promotes recovery in models of cerebral ischemia, intracerebral hemorrhage and trauma. Clinical studies report significant benefit for treating cardiac arrest and studies are investigating hypothermia for stroke and related conditions. Both local (head) and generalized hypothermia have been used. However, selective brain cooling has fewer side effects than systemic cooling. In this study, we developed a method to induce local (hemispheric) brain hypothermia in rats. The method involves using a small metal coil implanted between the Temporalis muscle and adjacent skull. This coil is then cooled by flushing it with cold water. In our first experiment, we tested whether this method induces focal brain hypothermia in anesthetized rats. Brain temperature was assessed in the ipsilateral cortex and striatum, and contralateral striatum, while body temperature was kept normothermic. Focal, ipsilateral cooling was successfully produced, while the other locations remained normothermic. In the second experiment, we implanted the coil, and brain and body temperature telemetry probes. The coil was connected via overhead swivel to a cold-water source. Brain hypothermia was produced for 24 h, while body temperature remained normothermic. A third experiment measured brain and body temperature along with heart rate and blood pressure. Brain cooling was produced for 24 h without significant alterations in pressure, heart rate or body temperature. In summary, our simple method allows for focal brain hypothermia to be safely induced in anesthetized or conscious rats, and is, therefore, ideally suited to stroke and trauma studies.
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Affiliation(s)
- Darren L Clark
- Center for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
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Vanhoutte G, Verhoye M, Van der Linden A. Changing body temperature affects the T2* signal in the rat brain and reveals hypothalamic activity. Magn Reson Med 2006; 55:1006-12. [PMID: 16598718 DOI: 10.1002/mrm.20861] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This study was designed to determine brain activity in the hypothalamus-in particular the thermoregulatory function of the hypothalamic preoptic area (PO). We experimentally changed the body temperature in rats within the physiological range (37-39 degrees C) and monitored changes in blood oxygenation level-dependent (BOLD) MR signal. To explore PO activity we had to deal with general signal changes caused by temperature-dependent alterations in the affinity of oxygen for hemoglobin, which contributes to BOLD contrast because it is partly sensitive to the amount of paramagnetic deoxyhemoglobin in the voxel. To reduce these overall temperature-induced effects, we corrected the BOLD data using brain-specific correction algorithms. The results showed activity of the PO during body warming from 38 degrees C to 39 degrees C, supported by an increased BOLD signal after correction. This is the first fMRI study on the autonomous nervous system in which hypothalamic activity elicited by changes in the internal environment (body temperature) was monitored. In this study we also demonstrate 1) that any fMRI study of anesthetized small animals should guard against background BOLD signal drift, since animals are vulnerable to body temperature fluctuations; and 2) the existence of a link between PO activity and the sympathetically-mediated opening of the arteriovenous anastomoses in a parallel study on the rat tail, a peripheral thermoregulatory organ.
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Affiliation(s)
- G Vanhoutte
- Bio-Imaging Laboratory, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
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Ma J, Zhao L, Nowak TS. Selective, reversible occlusion of the middle cerebral artery in rats by an intraluminal approach. J Neurosci Methods 2006; 156:76-83. [PMID: 16581135 DOI: 10.1016/j.jneumeth.2006.02.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 02/09/2006] [Accepted: 02/09/2006] [Indexed: 11/21/2022]
Abstract
These studies optimized design and application of an intraluminal filament method to achieve selective middle cerebral artery (MCA) occlusion in rats. Silicone plugs of 300 microm diameter and 700-800 microm length were molded onto 6-0 suture. These were introduced into Wistar rats previously fitted with telemetric probes, using established placement procedures, with and without heparinization. Temperature and activity were monitored for 3 days, after which lesion volumes were assessed by triphenyltetrazolium chloride staining. Optimized filaments entered the MCA in 85% of Wistar rats, failures being attributable to anatomical variation at its origin from the internal carotid artery. Infarcts restricted to the MCA territory were apparent after 90 min occlusion, and maximal after 3 h occlusion. Intraischemic hyperthermia was noted in a third of occlusions performed without heparin, but never with anticoagulant treatment. Permanent occlusions were also evaluated in Fisher, Lewis, Long-Evans, Spontaneously Hypertensive and Sprague-Dawley rats, and Wistar rats from a second supplier, and compared with data for surgical MCA occlusions. Success rates varied among strains, but infarct volumes correlated with those obtained after surgical occlusions in respective populations. These studies demonstrate the feasibility and limitations of reversible and selective intraluminal filament occlusion of the MCA in rats.
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Affiliation(s)
- Jianya Ma
- Department of Neurology, University of Tennessee, Memphis, TN 38163, USA
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Thoren AE, Helps SC, Nilsson M, Sims NR. The metabolism of C-glucose by neurons and astrocytes in brain subregions following focal cerebral ischemia in rats. J Neurochem 2006; 97:968-78. [PMID: 16606370 DOI: 10.1111/j.1471-4159.2006.03778.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To provide insights into the effects of temporary focal ischemia on the function of neurons and astrocytes in vivo, we measured the incorporation of radiolabel from [U-14C]glucose into both glutamate and glutamine in brain subregions at 1 h of reperfusion following occlusion of the middle cerebral artery for 2 or 3 h. Under the experimental conditions used, 14C-glutamate is mainly produced in neurons whereas 14C-glutamine is generated in astrocytes from 14C-glutamate of both neuronal and astrocytic origin. Radiolabel incorporation into both amino acids was greatly decreased. The change in 14C-glutamate accumulation provides strong evidence for substantial reductions in neuronal glucose metabolism. The resulting decrease in delivery of 14C-glutamate from the neurons to astrocytes was probably also the major contributor to the change in 14C-glutamine content. These alterations probably result in part from a marked depression of glycolytic activity in the neurons, as suggested by previous studies assessing deoxyglucose utilization. Alterations in 14C-glucose metabolism were not restricted to tissue that would subsequently become infarcted. Thus, these changes did not inevitably lead to death of the affected cells. The ATP : ADP ratio and phosphocreatine content were essentially preserved during recirculation following 2 h of ischemia and showed at most only moderate losses in some subregions following 3 h of ischemia. This retention of energy reserves despite the decreases in 14C-glucose metabolism in neurons suggests that energy needs were substantially reduced in the post-ischemic brain. Marked increases in tissue lactate accumulation during recirculation, particularly following 3 h of ischemia, provided evidence that impaired pyruvate oxidation probably also contributed to the altered 14C-glucose metabolism. These findings indicate the presence of complex changes in energy metabolism that are likely to greatly influence the responses of neurons and astrocytes to temporary focal ischemia.
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Affiliation(s)
- Anna E Thoren
- Centre for Neuroscience and Department of Medical Biochemistry, School of Medicine, Flinders University, Adelaide, Australia
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Karhunen H, Jolkkonen J, Sivenius J, Pitkänen A. Epileptogenesis after experimental focal cerebral ischemia. Neurochem Res 2006; 30:1529-42. [PMID: 16362772 DOI: 10.1007/s11064-005-8831-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2005] [Indexed: 12/01/2022]
Abstract
Cerebrovascular diseases are one of the most common causes of epilepsy in adults, and the incidence of stroke-induced epileptogenesis is increasing as the population ages. The mechanisms that lead to stroke-induced epileptogenesis in a subpopulation of patients, however, are still poorly understood. Recent advances in inducing epileptogenesis in rodent focal ischemia models have provided tools that can be used to identify the risk factors and neurobiologic changes leading to development of epilepsy after stroke. Here we summarize data from models in which epileptogenesis has been studied after focal ischemia; photothrombosis, middle cerebral artery (MCA) occlusion with filament, and endothelin-1-induced MCA occlusion. Analysis of the data indicates that neurobiologic changes occurring during stroke-induced epileptogenesis share some similarities to those induced by status epilepticus or traumatic brain injury.
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Affiliation(s)
- Heli Karhunen
- Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211, Kuopio, Finland
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Abstract
Cerebral ischemia results in a rapid depletion of energy stores that triggers a complex cascade of cellular events such as cellular depolarization and Ca2+ influx, resulting in excitotoxic cell death. The critical determinant of severity of brain injury is the duration and severity of the ischemic insult and early restoration of CBF. Induced therapeutic hypothermia following CA is the only strategy that has demonstrated improvement in outcomes in prospective, randomized clinical trials. Although pharmacologic neuro-protection has been disappointing thus far in a variety of experimental animal models, further research efforts are directed at using some agents that demonstrate marginal or moderate efficacy in combination with hypothermia. Although the signal transduction pathways and intracellular molecular events during cerebral ischemia and reperfusion are complex, potential therapeutic neuroprotective strategies hold promise for the future.
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Affiliation(s)
- Izumi Harukuni
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Division of Cardiac Anesthesiology, Tower 711, Johns Hopkins Hospital, 600 N. Wolfe Street, Baltimore, MD 21287, USA
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