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Mahmoud W, Hultborn H, Zuluaga J, Zrenner C, Zrenner B, Ziemann U, Ramos-Murguialday A. Testing spasticity mechanisms in chronic stroke before and after intervention with contralesional motor cortex 1 Hz rTMS and physiotherapy. J Neuroeng Rehabil 2023; 20:150. [PMID: 37941036 PMCID: PMC10631065 DOI: 10.1186/s12984-023-01275-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 11/01/2023] [Indexed: 11/10/2023] Open
Abstract
BACKGROUND Previous studies showed that repetitive transcranial magnetic stimulation (rTMS) reduces spasticity after stroke. However, clinical assessments like the modified Ashworth scale, cannot discriminate stretch reflex-mediated stiffness (spasticity) from passive stiffness components of resistance to muscle stretch. The mechanisms through which rTMS might influence spasticity are also not understood. METHODS We measured the effects of contralesional motor cortex 1 Hz rTMS (1200 pulses + 50 min physiotherapy: 3×/week, for 4-6 weeks) on spasticity of the wrist flexor muscles in 54 chronic stroke patients using a hand-held dynamometer for objective quantification of the stretch reflex response. In addition, we measured the excitability of three spinal mechanisms thought to be related to post-stroke spasticity: post-activation depression, presynaptic inhibition and reciprocal inhibition before and after the intervention. Effects on motor impairment and function were also assessed using standardized stroke-specific clinical scales. RESULTS The stretch reflex-mediated torque in the wrist flexors was significantly reduced after the intervention, while no change was detected in the passive stiffness. Additionally, there was a significant improvement in the clinical tests of motor impairment and function. There were no significant changes in the excitability of any of the measured spinal mechanisms. CONCLUSIONS We demonstrated that contralesional motor cortex 1 Hz rTMS and physiotherapy can reduce the stretch reflex-mediated component of resistance to muscle stretch without affecting passive stiffness in chronic stroke. The specific physiological mechanisms driving this spasticity reduction remain unresolved, as no changes were observed in the excitability of the investigated spinal mechanisms.
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Affiliation(s)
- Wala Mahmoud
- Institute for Clinical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany
- Hertie Institute for Clinical Brain Research, University of Tübingen, Eberhard Karls University Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | - Hans Hultborn
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Jagoba Zuluaga
- Institute for Clinical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Christoph Zrenner
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany
- Hertie Institute for Clinical Brain Research, University of Tübingen, Eberhard Karls University Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | - Brigitte Zrenner
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany
- Hertie Institute for Clinical Brain Research, University of Tübingen, Eberhard Karls University Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | - Ulf Ziemann
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany.
- Hertie Institute for Clinical Brain Research, University of Tübingen, Eberhard Karls University Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Ander Ramos-Murguialday
- Institute for Clinical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany
- Tecnalia, Basque Research and Technology Alliance, San Sebastián, Spain
- Athenea Neuroclinics, San Sebastián, Spain
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2
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Gupta S, Dutta S, Hui SP. Regenerative Potential of Injured Spinal Cord in the Light of Epigenetic Regulation and Modulation. Cells 2023; 12:1694. [PMID: 37443728 PMCID: PMC10341208 DOI: 10.3390/cells12131694] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/13/2023] [Accepted: 06/17/2023] [Indexed: 07/15/2023] Open
Abstract
A spinal cord injury is a form of physical harm imposed on the spinal cord that causes disability and, in many cases, leads to permanent mammalian paralysis, which causes a disastrous global issue. Because of its non-regenerative aspect, restoring the spinal cord's role remains one of the most daunting tasks. By comparison, the remarkable regenerative ability of some regeneration-competent species, such as some Urodeles (Axolotl), Xenopus, and some teleost fishes, enables maximum functional recovery, even after complete spinal cord transection. During the last two decades of intensive research, significant progress has been made in understanding both regenerative cells' origins and the molecular signaling mechanisms underlying the regeneration and reconstruction of damaged spinal cords in regenerating organisms and mammals, respectively. Epigenetic control has gradually moved into the center stage of this research field, which has been helped by comprehensive work demonstrating that DNA methylation, histone modifications, and microRNAs are important for the regeneration of the spinal cord. In this review, we concentrate primarily on providing a comparison of the epigenetic mechanisms in spinal cord injuries between non-regenerating and regenerating species. In addition, we further discuss the epigenetic mediators that underlie the development of a regeneration-permissive environment following injury in regeneration-competent animals and how such mediators may be implicated in optimizing treatment outcomes for spinal cord injurie in higher-order mammals. Finally, we briefly discuss the role of extracellular vesicles (EVs) in the context of spinal cord injury and their potential as targets for therapeutic intervention.
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Affiliation(s)
- Samudra Gupta
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India;
| | - Suman Dutta
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK;
| | - Subhra Prakash Hui
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India;
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3
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Kanno H, Matsumoto S, Yoshizumi T, Nakahara K, Shinonaga M, Kubo A, Fujii S, Ishizuka Y, Tanaka M, Ichihashi M, Murata H. SOCS7-Derived BC-Box Motif Peptide Mediated Cholinergic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells. Int J Mol Sci 2023; 24:ijms24032786. [PMID: 36769102 PMCID: PMC9917589 DOI: 10.3390/ijms24032786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/20/2023] [Accepted: 01/21/2023] [Indexed: 02/04/2023] Open
Abstract
Adipose-derived mesenchymal stem cells (ADMSCs) are a type of pluripotent somatic stem cells that differentiate into various cell types such as osteoblast, chondrocyte, and neuronal cells. ADMSCs as donor cells are used to produce regenerative medicines at hospitals and clinics. However, it has not been reported that ADMSCs were differentiated to a specific type of neuron with a peptide. Here, we report that ADMSCs differentiate to the cholinergic phenotype of neurons by the SOCS7-derived BC-box motif peptide. At operations for patients with neurological disorders, a small amount of subcutaneous fat was obtained. Two weeks later, adipose-derived mesenchymal stem cells (ADMSCs) were isolated and cultured for a further 1 to 2 weeks. Flow cytometry analysis for characterization of ADMSCs was performed with CD73, CD90, and CD105 as positive markers, and CD14, CD31, and CD56 as negative markers. The results showed that cultured cells were compatible with ADMSCs. Immunocytochemical studies showed naïve ADMSCs immunopositive for p75NTR, RET, nestin, keratin, neurofilament-M, and smooth muscle actin. ADMSCs were suggested to be pluripotent stem cells. A peptide corresponding to the amino-acid sequence of BC-box motif derived from SOCS7 protein was added to the medium at a concentration of 2 μM. Three days later, immunocytochemistry analysis, Western blot analysis, ubiquitination assay, and electrophysiological analysis with patch cramp were performed. Immunostaining revealed the expression of neurofilament H (NFH), choline acetyltransferase (ChAT), and tyrosine hydroxylase (TH). In addition, Western blot analysis showed an increase in the expression of NFH, ChAT, and TH, and the expression of ChAT was more distinct than TH. Immunoprecipitation with JAK2 showed an increase in the expression of ubiquitin. Electrophysiological analysis showed a large holding potential at the recorded cells through path electrodes. The BC-box motif peptide derived from SOCS7 promoted the cholinergic differentiation of ADMSCs. This novel method will contribute to research as well as regenerative medicine for cholinergic neuron diseases.
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Affiliation(s)
- Hiroshi Kanno
- Department of Neurosurgery, Yokohama City University, Yokohama 236-0004, Japan
- Department of Neurosurgery, Asahi Hospital, Tokyo 121-0078, Japan
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan
- Correspondence: ; Tel.: +81-3-5243-5800; Fax: +81-3-5242-5826
| | - Shutaro Matsumoto
- Department of Neurosurgery, Yokohama City University, Yokohama 236-0004, Japan
- Department of Neurosurgery, Asahi Hospital, Tokyo 121-0078, Japan
| | - Tetsuya Yoshizumi
- Department of Neurosurgery, Yokohama City University, Yokohama 236-0004, Japan
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan
- Department of Neurosurgery, St. Marianna Medical University of Medicine, Kawasaki 216-8511, Japan
| | - Kimihiro Nakahara
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan
| | - Masamichi Shinonaga
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan
| | | | - Satoshi Fujii
- Department of Neurosurgery, Asahi Hospital, Tokyo 121-0078, Japan
| | | | | | | | - Hidetoshi Murata
- Department of Neurosurgery, St. Marianna Medical University of Medicine, Kawasaki 216-8511, Japan
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Hordacre B, Austin D, Brown KE, Graetz L, Parees I, De Trane S, Vallence AM, Koblar S, Kleinig T, McDonnell MN, Greenwood R, Ridding MC, Rothwell JC. Evidence for a Window of Enhanced Plasticity in the Human Motor Cortex Following Ischemic Stroke. Neurorehabil Neural Repair 2021; 35:307-320. [PMID: 33576318 PMCID: PMC7610679 DOI: 10.1177/1545968321992330] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND In preclinical models, behavioral training early after stroke produces larger gains compared with delayed training. The effects are thought to be mediated by increased and widespread reorganization of synaptic connections in the brain. It is viewed as a period of spontaneous biological recovery during which synaptic plasticity is increased. OBJECTIVE To look for evidence of a similar change in synaptic plasticity in the human brain in the weeks and months after ischemic stroke. METHODS We used continuous theta burst stimulation (cTBS) to activate synapses repeatedly in the motor cortex. This initiates early stages of synaptic plasticity that temporarily reduces cortical excitability and motor-evoked potential amplitude. Thus, the greater the effect of cTBS on the motor-evoked potential, the greater the inferred level of synaptic plasticity. Data were collected from separate cohorts (Australia and UK). In each cohort, serial measurements were made in the weeks to months following stroke. Data were obtained for the ipsilesional motor cortex in 31 stroke survivors (Australia, 66.6 ± 17.8 years) over 12 months and the contralesional motor cortex in 29 stroke survivors (UK, 68.2 ± 9.8 years) over 6 months. RESULTS Depression of cortical excitability by cTBS was most prominent shortly after stroke in the contralesional hemisphere and diminished over subsequent sessions (P = .030). cTBS response did not differ across the 12-month follow-up period in the ipsilesional hemisphere (P = .903). CONCLUSIONS Our results provide the first neurophysiological evidence consistent with a period of enhanced synaptic plasticity in the human brain after stroke. Behavioral training given during this period may be especially effective in supporting poststroke recovery.
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Affiliation(s)
- Brenton Hordacre
- University of South Australia, IIMPACT in Health, Adelaide,
Australia
| | - Duncan Austin
- UCL Institute of Neurology, Queen Square, London, UK
| | | | - Lynton Graetz
- Lifespan Human Neurophysiology group, Adelaide Medical
School, The University of Adelaide, Australia
| | - Isabel Parees
- Servicio de Neurologia, Hospital Universitario Ramón
y Cajal, Madrid, Spain
- Servicio de Neurología, Hospital Ruber
Internacional, Madrid, Spain
| | - Stefania De Trane
- The Blizard Institute, Barts and The London School of
Medicine & Dentistry, Queen Mary University of London, London, UK
- Clinical Board: Medicine (Neuroscience), The Royal London
Hospital, Barts Health NHS Trust, London, UK
- National Hospital for Neurology and Neurosurgery, Queen
Square, London, UK
| | - Ann-Maree Vallence
- Discipline of Psychology, College of Science, Health,
Engineering and Education, Murdoch University, Western Australia, Australia
| | - Simon Koblar
- Department of Medicine, The University of Adelaide,
Adelaide, Australia
- Department of Neurology, Royal Adelaide Hospital,
Adelaide, Australia
| | - Timothy Kleinig
- Department of Medicine, The University of Adelaide,
Adelaide, Australia
- Department of Neurology, Royal Adelaide Hospital,
Adelaide, Australia
| | | | - Richard Greenwood
- National Hospital for Neurology and Neurosurgery, Queen
Square, London, UK
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Kwon H, Kevala K, Xin H, Patnaik S, Marugan J, Kim HY. Ligand-Induced GPR110 Activation Facilitates Axon Growth after Injury. Int J Mol Sci 2021; 22:ijms22073386. [PMID: 33806166 PMCID: PMC8037074 DOI: 10.3390/ijms22073386] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Recovery from axonal injury is extremely difficult, especially for adult neurons. Here, we demonstrate that the activation of G-protein coupled receptor 110 (GPR110, ADGRF1) is a mechanism to stimulate axon growth after injury. N-docosahexaenoylethanolamine (synaptamide), an endogenous ligand of GPR110 that promotes neurite outgrowth and synaptogenesis in developing neurons, and a synthetic GPR110 ligand stimulated neurite growth in axotomized cortical neurons and in retinal explant cultures. Intravitreal injection of GPR110 ligands following optic nerve crush injury promoted axon extension in adult wild-type, but not in gpr110 knockout, mice. In vitro axotomy or in vivo optic nerve injury rapidly induced the neuronal expression of gpr110. Activating the developmental mechanism of neurite outgrowth by specifically targeting GPR110 that is upregulated upon injury may provide a novel strategy for stimulating axon growth after nerve injury in adults.
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Affiliation(s)
- Heungsun Kwon
- Laboratory of Molecular Signaling, NIAAA, National Institutes of Health, 5625 Fishers Lane Room 3S-02, Rockville, MD 20892, USA; (H.K.); (K.K.)
| | - Karl Kevala
- Laboratory of Molecular Signaling, NIAAA, National Institutes of Health, 5625 Fishers Lane Room 3S-02, Rockville, MD 20892, USA; (H.K.); (K.K.)
| | - Hu Xin
- Division of Pre-Clinical Innovation, NCATS, National Institutes of Health, Rockville, MD 20852, USA; (H.X.); (S.P.); (J.M.)
| | - Samarjit Patnaik
- Division of Pre-Clinical Innovation, NCATS, National Institutes of Health, Rockville, MD 20852, USA; (H.X.); (S.P.); (J.M.)
| | - Juan Marugan
- Division of Pre-Clinical Innovation, NCATS, National Institutes of Health, Rockville, MD 20852, USA; (H.X.); (S.P.); (J.M.)
| | - Hee-Yong Kim
- Laboratory of Molecular Signaling, NIAAA, National Institutes of Health, 5625 Fishers Lane Room 3S-02, Rockville, MD 20892, USA; (H.K.); (K.K.)
- Correspondence: ; Tel.: +1-301-402-8746; Fax: +1-301-594-0035
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6
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Characterizing upper extremity motor behavior in the first week after stroke. PLoS One 2020; 15:e0221668. [PMID: 32776927 PMCID: PMC7416933 DOI: 10.1371/journal.pone.0221668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 06/15/2020] [Indexed: 12/15/2022] Open
Abstract
Background Animal models of brain recovery identify the first days after lesioning as a time of great flux in sensorimotor function and physiology. After rodent motor system lesioning, daily skill training in the less affected forelimb reduces skill acquisition in the more affected forelimb. We asked whether spontaneous human motor behaviors of the less affected upper extremity (UE) early after stroke resemble the animal training model, with the potential to suppress clinical recovery. Methods This prospective observational study used a convenience sample of patients (n = 25, mean 4.5 ±1.8) days after stroke with a wide severity range; Controls were hospitalized for non-neurological conditions (n = 12). Outcome measures were Accelerometry, Upper-Extremity Fugl-Meyer (UEFM), Action Research Arm Test (ARAT), Shoulder Abduction/ Finger Extension Test (SAFE), NIH Stroke Scale (NIHSS). Results Accelerometry indicated total paretic UE movement was reduced compared to controls, primarily due to a 44% reduction of bilateral UE use. Unilateral paretic movement was unchanged. Thus, movement shifted early after stroke; bilateral use was reduced and unilateral use of the non-paretic UE was increased by 77%. Low correlations between movement time and motor performance prompted an exploratory factor analysis (EFA) revealing a 2-component solution; motor performance tests load on one component (motor performance) whereas accelerometry-derived variables load on a second orthogonal component (quantity of movement). Conclusions Early after stroke, spontaneous overall UE movement is reduced, and movement shifts to unilateral use of the non-paretic UE. Two mechanisms that could influence motor recovery may already be in place 4.5 ± 1.8 days post stroke: (1) the overuse of the less affected UE, which could set the stage for learned non-use and (2) skill acquisition in the non-paretic limb that could impede recovery. Accurate UE motor assessment requires two independent constructs: motor performance and quantity of movement. These findings provide opportunities and measurement methods for studies to develop new behaviorally-based stroke recovery treatments that begin early after onset.
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7
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Yoshizumi T, Kubo A, Murata H, Shinonaga M, Kanno H. BC-Box Motif in SOCS6 Induces Differentiation of Epidermal Stem Cells into GABAnergic Neurons. Int J Mol Sci 2020; 21:ijms21144947. [PMID: 32668737 PMCID: PMC7403999 DOI: 10.3390/ijms21144947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/09/2020] [Accepted: 07/11/2020] [Indexed: 12/11/2022] Open
Abstract
The BC-box motif in suppressor of cytokine signaling 6 (SOCS6) promotes the neuronal differentiation of somatic stem cells, including epidermal stem cells. SOCS6 protein belongs to the group of SOCS proteins and inhibits cytokine signaling. Here we showed that epidermal stem cells were induced to differentiate into GABAnergic neurons by the intracellular delivery of a peptide composed of the amino-acid sequences encoded by the BC-box motif in SOCS6 protein. The BC-box motif (SLQYLCRFVI) in SOCS6 corresponded to the binding site of elongin BC. GABAnergic differentiation mediated by the BC-box motif in SOCS6 protein was caused by ubiquitination of JAK2 and inhibition of the JAK2-STAT3 pathway. Furthermore, GABAnergic neuron-like cells generated from epidermal stem cells were transplanted into the brain of a rodent ischemic model. Then, we demonstrated that these transplanted cells were GAD positive and that the cognitive function of the ischemic model rodents with the transplanted cells was improved. This study could contribute to not only elucidating the mechanism of GABAnergic neuronal differentiation but also to neuronal regenerative medicine utilizing GABAnergic neurons.
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Affiliation(s)
- Tetsuya Yoshizumi
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan; (T.Y.); (M.S.)
| | - Atsuhiko Kubo
- Nerve Care Clinic, Yokosuka 238-0012, Japan;
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan;
| | - Hidetoshi Murata
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan;
| | - Masamichi Shinonaga
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan; (T.Y.); (M.S.)
| | - Hiroshi Kanno
- Department of Neurosurgery, International University of Health and Welfare Atami Hospital, Atami 413-0012, Japan; (T.Y.); (M.S.)
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan;
- Correspondence: ; Tel.: +81-557-81-9171; Fax: +81-557-83-6632
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8
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Tabet F, Lee S, Zhu W, Levin MG, Toth CL, Cuesta Torres LF, Vinh A, Kim HA, Chu HX, Evans MA, Kuzmich ME, Drummond GR, Remaley AT, Rye KA, Sobey CG, Vickers KC. microRNA-367-3p regulation of GPRC5A is suppressed in ischemic stroke. J Cereb Blood Flow Metab 2020; 40:1300-1315. [PMID: 31296130 PMCID: PMC7238381 DOI: 10.1177/0271678x19858637] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ischemic stroke is a major cause of mortality and long-term disability with limited treatment options, and a greater understanding of the gene regulatory mechanisms underlying ischemic stroke-associated neuroinflammation is required for new therapies. To study ischemic stroke in vivo, mice were subjected to sustained ischemia by intraluminal filament-induced middle cerebral artery occlusion (MCAo) for 24 h without reperfusion or transient ischemia for 30 min followed by 23.5 h reperfusion, and brain miRNA and mRNA expression changes were quantified by TaqMan OpenArrays and gene (mRNA) expression arrays, respectively. Sustained ischemia resulted in 18 significantly altered miRNAs and 392 altered mRNAs in mouse brains compared to Sham controls; however, the transient ischemic condition was found to impact only 6 miRNAs and 126 mRNAs. miR-367-3p was found to be significantly decreased in brain homogenates with sustained ischemia. G protein-coupled receptor, family C, group 5, member A (Gprc5a), a miR-367-3p target gene, was found to be significantly increased with sustained ischemia. In primary neurons, inhibition of endogenous miR-367-3p resulted in a significant increase in Gprc5a expression. Moreover, miR-367-3p was found to be co-expressed with GPRC5A in human neurons. Results suggest that loss of miR-367-3p suppression of GPRC5A may contribute to neuroinflammation associated with ischemic stroke.
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Affiliation(s)
- Fatiha Tabet
- Mechanisms of Disease and Translational Research, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Seyoung Lee
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia
| | - Wanying Zhu
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael G Levin
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Cynthia L Toth
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Luisa F Cuesta Torres
- Mechanisms of Disease and Translational Research, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Antony Vinh
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia
| | - Hyun Ah Kim
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia
| | - Hannah X Chu
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia
| | - Megan A Evans
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia
| | - Meaghan E Kuzmich
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Grant R Drummond
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia
| | - Alan T Remaley
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kerry-Anne Rye
- Mechanisms of Disease and Translational Research, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Christopher G Sobey
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia
| | - Kasey C Vickers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
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9
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Functions of subventricular zone neural precursor cells in stroke recovery. Behav Brain Res 2019; 376:112209. [PMID: 31493429 DOI: 10.1016/j.bbr.2019.112209] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/11/2019] [Accepted: 09/03/2019] [Indexed: 12/16/2022]
Abstract
The proliferation and ectopic migration of neural precursor cells (NPCs) in response to ischemic brain injury was first reported two decades ago. Since then, studies of brain injury-induced subventricular zone cytogenesis, primarily in rodent models, have provided insight into the cellular and molecular determinants of this phenomenon and its modulation by various factors. However, despite considerable correlational evidence-and some direct evidence-to support contributions of NPCs to behavioral recovery after stroke, the causal mechanisms have not been identified. Here we discuss the subventricular zone cytogenic response and its possible roles in brain injury and disease, focusing on rodent models of stroke. Emerging evidence suggests that NPCs can modulate harmful responses and enhance reparative responses to neurologic diseases. We speculatively identify four broad functions of NPCs in the context of stroke: cell replacement, cytoprotection, remodeling of residual tissue, and immunomodulation. Thus, NPCs may have pleiotropic functions in supporting behavioral recovery after stroke.
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Abstract
Stroke remains a leading cause of disability and death worldwide despite significant scientific and therapeutic advances. Therefore, there is a critical need to improve stroke prevention and treatment. In this review, we describe several examples that leverage nucleic acid therapeutics to improve stroke care through prevention, acute treatment, and recovery. Aptamer systems are under development to increase the safety and efficacy of antithrombotic and thrombolytic treatment, which represent the mainstay of medical stroke therapy. Antisense oligonucleotide therapy has shown some promise in treating stroke causes that are genetically determined and resistant to classic prevention approaches such as elevated lipoprotein (a) and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Targeting microRNAs may be attractive because they regulate factors involved in neuronal cell death and reperfusion-associated injury, as well as neurorestorative pathways. Lastly, microRNAs may aid reliable etiologic classification of stroke subtypes, which is important for effective secondary stroke prevention.
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Affiliation(s)
- Nils Henninger
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
- Department of Psychiatry, University of Massachusetts Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
| | - Yunis Mayasi
- Division of Neurocritical Care, Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, 600 N. Wolfe Street, Baltimore, MD, 21287, USA
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11
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Nagalakshmi B., Sagarkar S, Sakharkar AJ. Epigenetic Mechanisms of Traumatic Brain Injuries. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 157:263-298. [DOI: 10.1016/bs.pmbts.2017.12.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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12
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Sarmah D, Kaur H, Saraf J, Pravalika K, Goswami A, Kalia K, Borah A, Wang X, Dave KR, Yavagal DR, Bhattacharya P. Getting Closer to an Effective Intervention of Ischemic Stroke: The Big Promise of Stem Cell. Transl Stroke Res 2017; 9:356-374. [PMID: 29075984 DOI: 10.1007/s12975-017-0580-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 12/13/2022]
Abstract
Stem cell therapy for ischemic stroke has widely been explored. Results from both preclinical and clinical studies have immensely supported the judicious use of stem cells as therapy. These provide an attractive means for preserving and replacing the damaged brain tissues following an ischemic attack. Since the past few years, researchers have used various types of stem cells to replenish insulted neuronal and glial cells in neurological disorders. In the present review, we discuss different types of stem cells employed for the treatment of ischemic stroke and mechanisms and challenges these cells face once introduced into the living system. Further, we also present different ways to maneuver and overcome challenges to translate the advances made at the preclinical level to clinics.
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Affiliation(s)
- Deepaneeta Sarmah
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Ahmedabad, Gandhinagar, Gujarat, 382355, India
| | - Harpreet Kaur
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Ahmedabad, Gandhinagar, Gujarat, 382355, India
| | - Jackson Saraf
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Ahmedabad, Gandhinagar, Gujarat, 382355, India
| | - Kanta Pravalika
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Ahmedabad, Gandhinagar, Gujarat, 382355, India
| | - Avirag Goswami
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kiran Kalia
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Ahmedabad, Gandhinagar, Gujarat, 382355, India
| | - Anupom Borah
- Cellular and Molecular Neurobiology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, Assam, India
| | - Xin Wang
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Kunjan R Dave
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Dileep R Yavagal
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Pallab Bhattacharya
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Ahmedabad, Gandhinagar, Gujarat, 382355, India.
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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Cianciulli A, Calvello R, Porro C, Trotta T, Panaro MA. Understanding the role of SOCS signaling in neurodegenerative diseases: Current and emerging concepts. Cytokine Growth Factor Rev 2017; 37:67-79. [DOI: 10.1016/j.cytogfr.2017.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/28/2017] [Accepted: 07/29/2017] [Indexed: 12/15/2022]
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Mu XP, Wang HB, Cheng X, Yang L, Sun XY, Qu HL, Zhao SS, Zhou ZK, Liu TT, Xiao T, Song B, Jolkkonen J, Zhao CS. Inhibition of Nkcc1 promotes axonal growth and motor recovery in ischemic rats. Neuroscience 2017; 365:83-93. [PMID: 28964752 DOI: 10.1016/j.neuroscience.2017.09.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 09/03/2017] [Accepted: 09/21/2017] [Indexed: 12/15/2022]
Abstract
Bumetanide is a selective inhibitor of the Na+-K+-Cl--co-transporter 1(NKCC1). We studied whether bumetanide could affect axonal growth and behavioral outcome in stroke rats. Adult male Wistar rats were randomly assigned to four groups: sham-operated rats treated with vehicle or bumetanide, and ischemic rats treated with vehicle or bumetanide. Endothelin-1 was used to induce focal cerebral ischemia. Bumetanide administration (i.c.v.) started on postoperative day 7 and continued for 3 weeks. Biotinylated dextran amine (BDA) was injected into the right imotor cortex on postoperative day 14 to trace corticospinal tract (CST) fibers sprouting into the denervated cervical spinal cord. Nogo-A, NKCC1, KCC2 and BDNF in the perilesional cortex and BDA, PSD-95 and vGlut1 in the denervated spinal cord were measured by immunohistochemistry and/or Western blot. Behavioral outcome of rats was assessed by the beam walking and cylinder tests. The total length of CST fibers sprouting into the denervated cervical spinal cord significantly increased after stroke and bumetanide further increased this sprouting. Bumetanide treatment also decreased the expressions of NKCC1 and Nogo-A, increased the expressions of KCC2 and BDNF in the perilesional cortex and enhanced the synaptic plasticity in the denervated cervical spinal cord after cerebral ischemia. The behavioral performance of ischemic rats was significantly improved by bumetanide. In conclusion, bumetanide promoted post-stroke axonal sprouting together accompanied by an improved behavioral outcome possibly through restoring and maintaining neuronal chloride homeostasis and creating a recovery-promoting microenvironment by overcoming the axonal growth inhibition encountered after cerebral ischemia in rats.
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Affiliation(s)
- X P Mu
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China; Department of Neurology, The Fourth Affiliated Hospital, China Medical University, Shenyang, China
| | - H B Wang
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - X Cheng
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - L Yang
- Department of Cardiology, The Affiliated Center Hospital, Shenyang Medical College, Shenyang, China
| | - X Y Sun
- Department of Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - H L Qu
- Department of Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - S S Zhao
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Z K Zhou
- Department of Geriatrics, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - T T Liu
- Department of Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - T Xiao
- Department of Dermatology, The First Affiliated Hospital, China Medical University, Shenyang, China; Key Laboratory of Immunodermatology, Ministry of Health, Ministry of Education, Shenyang, China
| | - B Song
- Regenerative Medicine, Cardiff Institute of Tissue Engineering and Repair, School of Dentistry, Cardiff University, Cardiff, UK
| | - J Jolkkonen
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, P. O. Box 1627, 70211 Kuopio, Finland
| | - C S Zhao
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China.
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Pena-Philippides JC, Caballero-Garrido E, Lordkipanidze T, Roitbak T. In vivo inhibition of miR-155 significantly alters post-stroke inflammatory response. J Neuroinflammation 2016; 13:287. [PMID: 27829437 PMCID: PMC5103429 DOI: 10.1186/s12974-016-0753-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 10/27/2016] [Indexed: 12/12/2022] Open
Abstract
Background MicroRNA miR-155 is implicated in modulation of the inflammatory processes in various pathological conditions. In our previous studies, we demonstrated that in vivo inhibition of miR-155 promotes functional recovery after mouse experimental stroke. In the present study, we explored if this beneficial effect is associated with miR-155 inhibition-induced alterations in post-stroke inflammatory response. Methods Intravenous injections of a specific miR-155 inhibitor were initiated at 48 h after mouse distal middle cerebral artery occlusion (dMCAO). Temporal changes in the expression of cytokines and key molecules associated with cytokine signaling were assessed at 7, 14, and 21 days after dMCAO, using mouse cytokine gene and protein arrays and Western blot analyses. Electron and immunofluorescence confocal microscopy techniques were used to evaluate the ultrastructural changes, as well as altered expression of specific phenotypic markers, at different time points after dMCAO. Results In the inhibitor-injected mice (inhibitor group), there was a significant decrease in CCL12 and CXCL3 cytokine expression at 7 days and significantly increased levels of major cytokines IL-10, IL-4, IL-6, MIP-1α, IL-5, and IL-17 at 14 days after dMCAO. These temporal changes correlated with altered expression of miR-155 target proteins SOCS-1, SHIP-1, and C/EBP-β and phosphorylation levels of cytokine signaling regulator STAT-3. Electron microscopy showed decreased number of phagocytically active peri-vascular microglia/macrophages in the inhibitor samples. Immunofluorescence and Western blot of these samples demonstrated that expression of leukocyte/ macrophage marker CD45 and phagocytosis marker CD68 was reduced at 7 days, and in contrast, significantly increased at 14 days after dMCAO, as compared to controls. Conclusions Based on our findings, we propose that in vivo miR-155 inhibition following mouse stroke significantly alters the time course of the expression of major cytokines and inflammation-associated molecules, which could influence inflammation process and tissue repair after experimental cerebral ischemia. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0753-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan Carlos Pena-Philippides
- Department of Neurosurgery, University of New Mexico Health Sciences Center, 1101 Yale Blvd, Albuquerque, NM, 87106-3834, USA
| | - Ernesto Caballero-Garrido
- Department of Neurosurgery, University of New Mexico Health Sciences Center, 1101 Yale Blvd, Albuquerque, NM, 87106-3834, USA
| | | | - Tamara Roitbak
- Department of Neurosurgery, University of New Mexico Health Sciences Center, 1101 Yale Blvd, Albuquerque, NM, 87106-3834, USA.
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Feeding the brain and nurturing the mind: Linking nutrition and the gut microbiota to brain development. Proc Natl Acad Sci U S A 2016; 112:14105-12. [PMID: 26578751 DOI: 10.1073/pnas.1511465112] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The human gut contains a microbial community composed of tens of trillions of organisms that normally assemble during the first 2-3 y of postnatal life. We propose that brain development needs to be viewed in the context of the developmental biology of this "microbial organ" and its capacity to metabolize the various diets we consume. We hypothesize that the persistent cognitive abnormalities seen in children with undernutrition are related in part to their persistent gut microbiota immaturity and that specific regions of the brain that normally exhibit persistent juvenile (neotenous) patterns of gene expression, including those critically involved in various higher cognitive functions such as the brain's default mode network, may be particularly vulnerable to the effects of microbiota immaturity in undernourished children. Furthermore, we postulate that understanding the interrelationships between microbiota and brain metabolism in childhood undernutrition could provide insights about responses to injury seen in adults. We discuss approaches that can be used to test these hypotheses, their ramifications for optimizing nutritional recommendations that promote healthy brain development and function, and the potential societal implications of this area of investigation.
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Eckert A, Huang L, Gonzalez R, Kim HS, Hamblin MH, Lee JP. Bystander Effect Fuels Human Induced Pluripotent Stem Cell-Derived Neural Stem Cells to Quickly Attenuate Early Stage Neurological Deficits After Stroke. Stem Cells Transl Med 2015; 4:841-51. [PMID: 26025980 DOI: 10.5966/sctm.2014-0184] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 04/06/2015] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED : Present therapies for stroke rest with tissue plasminogen activator (tPA), the sole licensed antithrombotic on the market; however, tPA's effectiveness is limited in that the drug not only must be administered less than 3-5 hours after stroke but often exacerbates blood-brain barrier (BBB) leakage and increases hemorrhagic incidence. A potentially promising therapy for stroke is transplantation of human induced pluripotent stem cell-derived neural stem cells (hiPSC-NSCs). To date, the effects of iPSCs on injuries that take place during early stage ischemic stroke have not been well studied. Consequently, we engrafted iPSC-NSCs into the ipsilesional hippocampus, a natural niche of NSCs, at 24 hours after stroke (prior to secondary BBB opening and when inflammatory signature is abundant). At 48 hours after stroke (24 hours after transplant), hiPSC-NSCs had migrated to the stroke lesion and quickly improved neurological function. Transplanted mice showed reduced expression of proinflammatory factors (tumor necrosis factor-α, interleukin 6 [IL-6], IL-1β, monocyte chemotactic protein 1, macrophage inflammatory protein 1α), microglial activation, and adhesion molecules (intercellular adhesion molecule 1, vascular cell adhesion molecule 1) and attenuated BBB damage. We are the first to report that engrafted hiPSC-NSCs rapidly improved neurological function (less than 24 hours after transplant). Rapid hiPSC-NSC therapeutic activity is mainly due to a bystander effect that elicits reduced inflammation and BBB damage. SIGNIFICANCE Clinically, cerebral vessel occlusion is rarely permanent because of spontaneous or thrombolytic therapy-mediated reperfusion. These results have clinical implications indicating a much extended therapeutic window for transplantation of human induced pluripotent stem cell-derived neural stem cells (hiPSC-NSCs; 24 hours after stroke as opposed to the 5-hour window with tissue plasminogen activator [tPA]). In addition, there is potential for a synergistic effect by combining hiPSC-NSC transplantation with tPA to attenuate stroke's adverse effects.
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Affiliation(s)
- Auston Eckert
- Center for Stem Cell Research and Regenerative Medicine, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Sanford-Burnham Institute for Medical Research, Neuroscience, Aging and Stem Cell Research, La Jolla, California, USA; Seoul National University, College of Medicine, Department of Pharmacology, Seoul, Republic of Korea
| | - Lei Huang
- Center for Stem Cell Research and Regenerative Medicine, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Sanford-Burnham Institute for Medical Research, Neuroscience, Aging and Stem Cell Research, La Jolla, California, USA; Seoul National University, College of Medicine, Department of Pharmacology, Seoul, Republic of Korea
| | - Rodolfo Gonzalez
- Center for Stem Cell Research and Regenerative Medicine, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Sanford-Burnham Institute for Medical Research, Neuroscience, Aging and Stem Cell Research, La Jolla, California, USA; Seoul National University, College of Medicine, Department of Pharmacology, Seoul, Republic of Korea
| | - Hye-Sun Kim
- Center for Stem Cell Research and Regenerative Medicine, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Sanford-Burnham Institute for Medical Research, Neuroscience, Aging and Stem Cell Research, La Jolla, California, USA; Seoul National University, College of Medicine, Department of Pharmacology, Seoul, Republic of Korea
| | - Milton H Hamblin
- Center for Stem Cell Research and Regenerative Medicine, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Sanford-Burnham Institute for Medical Research, Neuroscience, Aging and Stem Cell Research, La Jolla, California, USA; Seoul National University, College of Medicine, Department of Pharmacology, Seoul, Republic of Korea
| | - Jean-Pyo Lee
- Center for Stem Cell Research and Regenerative Medicine, Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Sanford-Burnham Institute for Medical Research, Neuroscience, Aging and Stem Cell Research, La Jolla, California, USA; Seoul National University, College of Medicine, Department of Pharmacology, Seoul, Republic of Korea
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Silasi G, Murphy TH. Stroke and the connectome: how connectivity guides therapeutic intervention. Neuron 2015; 83:1354-68. [PMID: 25233317 DOI: 10.1016/j.neuron.2014.08.052] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2014] [Indexed: 11/30/2022]
Abstract
Connections between neurons are affected within 3 min of stroke onset by massive ischemic depolarization and then delayed cell death. Some connections can recover with prompt reperfusion; others associated with the dying infarct do not. Disruption in functional connectivity is due to direct tissue loss and indirect disconnections of remote areas known as diaschisis. Stroke is devastating, yet given the brain's redundant design, collateral surviving networks and their connections are well-positioned to compensate. Our perspective is that new treatments for stroke may involve a rational functional and structural connections-based approach. Surviving, affected, and at-risk networks can be identified and targeted with scenario-specific treatments. Strategies for recovery may include functional inhibition of the intact hemisphere, rerouting of connections, or setpoint-mediated network plasticity. These approaches may be guided by brain imaging and enabled by patient- and injury-specific brain stimulation, rehabilitation, and potential molecule-based strategies to enable new connections.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Brain Research Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Brain Research Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Huang L, Wong S, Snyder EY, Hamblin MH, Lee JP. Human neural stem cells rapidly ameliorate symptomatic inflammation in early-stage ischemic-reperfusion cerebral injury. Stem Cell Res Ther 2014; 5:129. [PMID: 25418536 PMCID: PMC4445985 DOI: 10.1186/scrt519] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 11/04/2014] [Indexed: 01/03/2023] Open
Abstract
Introduction Clinically, a good deal of injury from stroke results from ischemic-reperfusion. There is a loss of cerebral parenchyma and its associated cells, disruption of neuronal connections, compromise of the blood-brain barrier, and inflammation. We tested whether exogenously engrafted human neural stem cells could migrate rapidly and extensively to damaged regions, following transplantation into a neurogenic site where migration cues are already underway during stroke onset, then counteract a number of these pathological processes. Methods One day post-injury, we injected human neural stem cells (hNSCs) into the ipsilesional hippocampus of a mouse model of stroke with middle cerebral artery occlusion to induce focal ischemia followed by reperfusion (MCAO/R). The time frame for hNSC transplantation corresponded to upregulation of endogenous proinflammatory cytokines. We examined the effect of hNSC transplantation on pathological processes and behavioral dysfunction 48 hours post-injury. Results Twenty-four hours after transplantation, engrafted hNSCs had migrated extensively to the lesion, and infarct volume was reduced relative to MCAO/R controls. The behavioral deficits seen in MCAO/R controls were also significantly improved. Given this rapid response, we hypothesized that the mechanisms underlying therapeutic activity were anti-inflammatory rather than due to cell replacement. In support of this idea, in hNSC-transplanted mice we observed reduced microglial activation, decreased expression of proinflammatory factors (tumor necrosis factor-α, interleukin (IL)-6, IL-1β, monocyte chemotactic protein-1, macrophage inflammatory protein-1α) and adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1), and amelioration of blood-brain barrier damage. Conclusions While long-term effects of engrafted hNSCs on the amelioration of ischemic stroke-induced behavioral dysfunction in a rodent model have been reported, our study is the first to show rapid, beneficial impacts on behavioral function (within 24 hours) upon early delivery of hNSCs into the hippocampus. Electronic supplementary material The online version of this article (doi:10.1186/scrt519) contains supplementary material, which is available to authorized users.
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Li JZ. Circadian rhythms and mood: opportunities for multi-level analyses in genomics and neuroscience: circadian rhythm dysregulation in mood disorders provides clues to the brain's organizing principles, and a touchstone for genomics and neuroscience. Bioessays 2013; 36:305-15. [PMID: 24853393 PMCID: PMC4033528 DOI: 10.1002/bies.201300141] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the healthy state, both circadian rhythm and mood are stable against perturbations, yet they are capable of adjusting to altered internal cues or ongoing changes in external conditions. The dual demands of stability and flexibility are met by the collective properties of complex neural networks. Disruption of this balance underlies both circadian rhythm abnormality and mood disorders. However, we do not fully understand the network properties that govern the crosstalk between the circadian system and mood regulation. This puzzle reflects a challenge at the center of neurobiology, and its solution requires the successful integration of existing data across all levels of neural organization, from molecules, cells, circuits, network dynamics, to integrated mental function. This essay discusses several open questions confronting the cross-level synthesis, and proposes that circadian regulation, and its role in mood, stands as a uniquely tractable system to study the causal mechanisms of neural adaptation.
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Affiliation(s)
- Jun Z Li
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
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21
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Vemuganti R. All's well that transcribes well: non-coding RNAs and post-stroke brain damage. Neurochem Int 2013; 63:438-49. [PMID: 23954844 PMCID: PMC3805745 DOI: 10.1016/j.neuint.2013.07.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/26/2013] [Accepted: 07/28/2013] [Indexed: 12/13/2022]
Abstract
The mammalian genome is replete with various classes of non-coding (nc) RNA genes. Many of them actively transcribe, and their relevance to CNS diseases is just beginning to be understood. CNS is one of the organs in the body that shows very high ncRNAs activity. Recent studies demonstrated that cerebral ischemia rapidly changes the expression profiles of different classes of ncRNAs: including microRNA, long noncoding RNA and piwi-interacting RNA. Several studies further showed that post-ischemic neuronal death and/or plasticity/regeneration can be altered by modulating specific microRNAs. These studies are of interest for therapeutic development as they may contribute to identifying new ncRNA targets that can be modulated to prevent secondary brain damage after stroke.
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Affiliation(s)
- Raghu Vemuganti
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA.
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Abstract
Spinal cord injury results from an insult inflicted on the spinal cord that usually encompasses its 4 major functions (motor, sensory, autonomic, and reflex). The type of deficits resulting from spinal cord injury arise from primary insult, but their long-term severity is due to a multitude of pathophysiological processes during the secondary phase of injury. The failure of the mammalian spinal cord to regenerate and repair is often attributed to the very feature that makes the central nervous system special-it becomes so highly specialized to perform higher functions that it cannot effectively reactivate developmental programs to re-build novel circuitry to restore function after injury. Added to this is an extensive gliotic and immune response that is essential for clearance of cellular debris, but also lays down many obstacles that are detrimental to regeneration. Here, we discuss how the mature chromatin state of different central nervous system cells (neural, glial, and immune) may contribute to secondary pathophysiology, and how restoring silenced developmental gene expression by altering histone acetylation could stall secondary damage and contribute to novel approaches to stimulate endogenous repair.
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Affiliation(s)
- Elisa M. York
- Department of Zoology (Life Sciences Institute), Brain Research Institute and International Collaboration on Repair Discoveries (iCORD), University of British Columbia, 2350 Health Sciences Blvd, V6T 1Z3 Vancouver, Canada
| | - Audrey Petit
- Department of Zoology (Life Sciences Institute), Brain Research Institute and International Collaboration on Repair Discoveries (iCORD), University of British Columbia, 2350 Health Sciences Blvd, V6T 1Z3 Vancouver, Canada
| | - A. Jane Roskams
- Department of Zoology (Life Sciences Institute), Brain Research Institute and International Collaboration on Repair Discoveries (iCORD), University of British Columbia, 2350 Health Sciences Blvd, V6T 1Z3 Vancouver, Canada
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Age-dependent modulation of cortical transcriptomes in spinal cord injury and repair. PLoS One 2012; 7:e49812. [PMID: 23236355 PMCID: PMC3517588 DOI: 10.1371/journal.pone.0049812] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/16/2012] [Indexed: 11/19/2022] Open
Abstract
Both injury and aging of the central nervous system reportedly produce profound changes in gene expression. Therefore, aging may interfere with the success of therapeutic interventions which were tailored for young patients. Using genome-scale transcriptional profiling, we identified distinct age-dependent expression profiles in rat sensorimotor cortex during acute, subacute and chronic phases of spinal cord injury (SCI). Aging affects the cortical transcriptomes triggered by transection of the corticospinal tract as there was only a small overlap between the significantly lesion-regulated genes in both age groups. Over-representation analysis of the lesion-regulated genes revealed that, in addition to biological processes in common, such as lipid metabolism, others, such as activation of complement cascade, were specific for aged animals. When a recently developed treatment to suppress fibrotic scarring (anti-scarring treatment AST) was applied to the injured spinal cord of aged (22 months) and young (2 months) rats, we found that the cortical gene expression in old rats was modulated to resemble regeneration-associated profiles of young animals including the up-regulation of known repair promoting growth and transcription factors at 35 dpo. In combination with recent immunohistochemical findings demonstrating regenerative axon growth upon AST in aged animals, the present investigation on the level of gene expression strongly supports the feasibility of a successful AST therapy in elderly patients.
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Coulthard MG, Morgan M, Woodruff TM, Arumugam TV, Taylor SM, Carpenter TC, Lackmann M, Boyd AW. Eph/Ephrin signaling in injury and inflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1493-503. [PMID: 23021982 DOI: 10.1016/j.ajpath.2012.06.043] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 06/28/2012] [Indexed: 12/20/2022]
Abstract
The Eph/ephrin receptor-ligand system plays an important role in embryogenesis and adult life, principally by influencing cell behavior through signaling pathways, resulting in modification of the cell cytoskeleton and cell adhesion. There are 10 EphA receptors, and six EphB receptors, distinguished on sequence difference and binding preferences, that interact with the six glycosylphosphatidylinositol-linked ephrin-A ligands and the three transmembrane ephrin-B ligands, respectively. The Eph/ephrin proteins, originally described as developmental regulators that are expressed at low levels postembryonically, are re-expressed after injury to the optic nerve, spinal cord, and brain in fish, amphibians, rodents, and humans. In rodent spinal cord injury, the up-regulation of EphA4 prevents recovery by inhibiting axons from crossing the injury site. Eph/ephrin proteins may be partly responsible for the phenotypic changes to the vascular endothelium in inflammation, which allows fluid and inflammatory cells to pass from the vascular space into the interstitial tissues. Specifically, EphA2/ephrin-A1 signaling in the lung may be responsible for pulmonary inflammation in acute lung injury. A role in T-cell maturation and chronic inflammation (heart failure, inflammatory bowel disease, and rheumatoid arthritis) is also reported. Although there remains much to learn about Eph/ephrin signaling in human disease, and specifically in injury and inflammation, this area of research raises the exciting prospect that novel therapies will be developed that precisely target these pathways.
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Affiliation(s)
- Mark G Coulthard
- Academic Discipline of Paediatrics and Child Health, University of Queensland, Royal Children's Hospital, Herston, Australia.
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Kubota K, Saiwai H, Kumamaru H, Kobayakawa K, Maeda T, Matsumoto Y, Harimaya K, Iwamoto Y, Okada S. Neurological recovery is impaired by concurrent but not by asymptomatic pre-existing spinal cord compression after traumatic spinal cord injury. Spine (Phila Pa 1976) 2012; 37:1448-55. [PMID: 22414995 DOI: 10.1097/brs.0b013e31824ffda5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An in vivo animal study to examine the influence of pre-existing or concurrent spinal canal stenosis (SCS) on the functional recovery after spinal cord injury (SCI). OBJECTIVES To clarify whether spinal cord compression before or after SCI results in less favorable neurological recovery. SUMMARY OF BACKGROUND DATA The influence of spinal cord compression on the neurological recovery after SCI remains unclear. METHODS We created mice with SCS using an extradural spacer before or after producing SCI and statistically analyzed the correlation between the extent of SCS and neurological outcomes. The extent of SCS was calculated by micro-computed tomography, and the spinal cord blood flow (SCBF) was measured serially with laser Doppler flowmetry. Molecular and immunohistochemical examinations were performed to evaluate the neovascularization at the site of cord compression. RESULTS Spacer placement (<300 μm) alone in the control mouse resulted in no neurological deficits. Even with spacer placement that caused asymptomatic SCS, the functional recovery after SCI was progressively impaired as spacer sizes increased in the mice with SCS co-occurring with SCI, whereas no significant impact was observed in the mice with pre-existing SCS, irrespective of the spacer sizes. The SCBF progressively decreased immediately after SCS was produced, but it fully recovered at the later time points. Angiogenesis-related genes were upregulated, and neovascular vessels were observed after producing the SCS. We found that concurrent SCS resulted in a significant reduction and impaired the subsequent recovery of the SCBF, whereas pre-existing SCS did not affect the hemodynamics of the spinal cord after SCI. CONCLUSION The dynamic reduction of the SCBF occurring immediately after spinal cord compression is a significant factor that impairs the neurological recovery after SCI, whereas pre-existing SCS is not always an impediment due to the potentially restructured SCBF.
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Affiliation(s)
- Kensuke Kubota
- Departments of Orthopaedic Surgery and Advanced Medical Initiatives, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Prokineticin 2 is an endangering mediator of cerebral ischemic injury. Proc Natl Acad Sci U S A 2012; 109:5475-80. [PMID: 22431614 DOI: 10.1073/pnas.1113363109] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stroke causes brain dysfunction and neuron death, and the lack of effective therapies heightens the need for new therapeutic targets. Here we identify prokineticin 2 (PK2) as a mediator for cerebral ischemic injury. PK2 is a bioactive peptide initially discovered as a regulator of gastrointestinal motility. Multiple biological roles for PK2 have been discovered, including circadian rhythms, angiogenesis, and neurogenesis. However, the role of PK2 in neuropathology is unknown. Using primary cortical cultures, we found that PK2 mRNA is up-regulated by several pathological stressors, including hypoxia, reactive oxygen species, and excitotoxic glutamate. Glutamate-induced PK2 expression is dependent on NMDA receptor activation and extracellular calcium. Enriched neuronal culture studies revealed that neurons are the principal source of glutamate-induced PK2. Using in vivo models of stroke, we found that PK2 mRNA is induced in the ischemic cortex and striatum. Central delivery of PK2 worsens infarct volume, whereas PK2 receptor antagonist decreases infarct volume and central inflammation while improving functional outcome. Direct central inhibition of PK2 using RNAi also reduces infarct volume. These findings indicate that PK2 can be activated by pathological stimuli such as hypoxia-ischemia and excitotoxic glutamate and identify PK2 as a deleterious mediator for cerebral ischemia.
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SC1/hevin and reactive gliosis after transient ischemic stroke in young and aged rats. J Neuropathol Exp Neurol 2011; 70:913-29. [PMID: 21937915 DOI: 10.1097/nen.0b013e318231151e] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SC1 is a member of the SPARC family of glycoproteins that regulate cell-matrix interactions in the developing brain. SC1 is expressed in astrocytes, but nothing is known about the expression in the aged or after stroke. We found that after focal striatal ischemic infarction in adult rats, SC1 increased in astrocytes surrounding the infarct and in the glial scar, but in aged rats, SC1 was lower at the lesion edge. Glial fibrillary acidic protein (GFAP) also increased, but it was less prominent in reactive astrocytes further from the lesion in the aged rats. On the basis of their differential expression of several molecules, 2 types of reactive astrocytes with differing spatiotemporal distributions were identified. On Days 3 and 7, SC1 was prevalent in cells expressing markers of classic reactive astrocytes (GFAP, vimentin, nestin, S100β), as well as apoliprotein E (ApoE), interleukin 1β, aggrecanase 1 (ADAMTS4), and heat shock protein 25 (Hsp25). Adjacent to the lesion on Days 1 and 3, astrocytes with low GFAP levels and a "starburst" SC1 pattern expressed S100β, ApoE, and Hsp32 but not vimentin, nestin, interleukin 1β, ADAMTS4, or Hsp25. Neither cell type was immunoreactive for NG2,CC-1, CD11b, or ionized calcium-binding adapter-1. Their differing expression of inflammation-related and putatively protective molecules suggests different roles for starburst and classic reactive astrocytes in the early glial responses to ischemia.
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Abstract
Whole genome expression microarrays can be used to study gene expression in blood, which comes in part from leukocytes, immature platelets, and red blood cells. Since these cells are important in the pathogenesis of stroke, RNA provides an index of these cellular responses to stroke. Our studies in rats have shown specific gene expression changes 24 hours after ischemic stroke, hemorrhage, status epilepticus, hypoxia, hypoglycemia, global ischemia, and following brief focal ischemia that simulated transient ischemic attacks in humans. Human studies show gene expression changes following ischemic stroke. These gene profiles predict a second cohort with >90% sensitivity and specificity. Gene profiles for ischemic stroke caused by large-vessel atherosclerosis and cardioembolism have been described that predict a second cohort with >85% sensitivity and specificity. Atherosclerotic genes were associated with clotting, platelets, and monocytes, and cardioembolic genes were associated with inflammation, infection, and neutrophils. These gene profiles predicted the cause of stroke in 58% of cryptogenic patients. These studies will provide diagnostic, prognostic, and therapeutic markers, and will advance our understanding of stroke in humans. New techniques to measure all coding and noncoding RNAs along with alternatively spliced transcripts will markedly advance molecular studies of human stroke.
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Abstract
Approximately one-third of patients with stroke exhibit persistent disability after the initial cerebrovascular episode, with motor impairments accounting for most poststroke disability. Exercise and training have long been used to restore motor function after stroke. Better training strategies and therapies to enhance the effects of these rehabilitative protocols are currently being developed for poststroke disability. The advancement of our understanding of the neuroplastic changes associated with poststroke motor impairment and the innate mechanisms of repair is crucial to this endeavor. Pharmaceutical, biological and electrophysiological treatments that augment neuroplasticity are being explored to further extend the boundaries of poststroke rehabilitation. Potential motor rehabilitation therapies, such as stem cell therapy, exogenous tissue engineering and brain-computer interface technologies, could be integral in helping patients with stroke regain motor control. As the methods for providing motor rehabilitation change, the primary goals of poststroke rehabilitation will be driven by the activity and quality of life needs of individual patients. This Review aims to provide a focused overview of neuroplasticity associated with poststroke motor impairment, and the latest experimental interventions being developed to manipulate neuroplasticity to enhance motor rehabilitation.
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Affiliation(s)
- Michael A Dimyan
- Human Cortical Physiology and Stroke Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892-1428, USA
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Freedman JE, Vitseva O, Tanriverdi K. The role of the blood transcriptome in innate inflammation and stroke. Ann N Y Acad Sci 2010; 1207:41-5. [PMID: 20955424 DOI: 10.1111/j.1749-6632.2010.05731.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cerebrovascular disease is a major cause of death and disability, with a poorer outcome in patients having select risk factors including diabetes and hypertension. Risk factors and the state of cerebral ischemia-reperfusion associated with cerebrovascular occlusion are known to cause inflammatory changes. These events and the inflammatory state are reflected by transcript changes in various components of the blood and can be specifically measured. By defining these changes, new insight into cerebrovascular disease and its therapeutics is being achieved.
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Affiliation(s)
- Jane E Freedman
- Whitaker Cardiovascular Institute and Evans Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA.
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Iaci JF, Ganguly A, Finklestein SP, Parry TJ, Ren J, Saha S, Sietsma DK, Srinivas M, Vecchione AM, Caggiano AO. Glial growth factor 2 promotes functional recovery with treatment initiated up to 7 days after permanent focal ischemic stroke. Neuropharmacology 2010; 59:640-9. [PMID: 20691195 DOI: 10.1016/j.neuropharm.2010.07.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 07/07/2010] [Accepted: 07/22/2010] [Indexed: 12/15/2022]
Abstract
Neuregulins are a family of growth factors essential for normal cardiac and nervous system development. The EGF-like domain of neuregulins contains the active site which binds and activates signaling cascades through ErbB receptors. A neuregulin-1 gene EGF-like fragment demonstrated neuroprotection in the transient middle cerebral artery occlusion (MCAO) stroke model and drastically reduced infarct volume (Xu et al., 2004). Here we use a permanent MCAO rat model to initially compare two products of the neuregulin-1 gene and also assess levels of recovery with acute versus delayed time to treatment. In the initial study full-length glial growth factor 2 (GGF2) and an EGF-like domain fragment were compared with acute intravenous delivery. In a second study GGF2 only was delivered starting at 24h, 3 days or 7 days after permanent ischemia was induced. In both studies daily intravenous administration continued for 10 days. Recovery of neurological function was assessed using limb placing and body swing tests. GGF2 had similar functional improvements compared to the EGF-like domain fragment at equimolar doses, and a higher dose of GGF2 demonstrated more robust functional improvements compared to a lower dose. GGF2 improved sensorimotor recovery with all treatment paradigms, even enhancing recovery of function with a delay of 7 days to treatment. Histological assessments did not show any associated reduction in infarct volume at either 48 h or 21 days post-ischemic event. Neurorestorative effects of this kind are of great potential clinical importance, given the difficulty of delivering neuroprotective therapies within a short time after an ischemic event in human patients. If confirmed by additional work including additional data on mechanism(s) of improved outcome with verification in other stroke models, one can make a compelling case to bring GGF2 to clinical trials as a neurorestorative approach to improving outcome following stroke injury.
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Affiliation(s)
- Jennifer F Iaci
- Acorda Therapeutics Inc., 15 Skyline Drive, Hawthorne, NY 10532, USA.
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Csiba L, Farkas S, Kollár J, Berényi E, Nagy K, Bereczki D. Visualization of the ischemic core on native human brain slices by potassium staining method. J Neurosci Methods 2010; 192:17-21. [PMID: 20624426 DOI: 10.1016/j.jneumeth.2010.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/01/2010] [Accepted: 07/02/2010] [Indexed: 10/19/2022]
Abstract
The potassium staining method is based on the formation of potassium cobaltnitrite crystals after the treatment by sodium cobaltnitrite of brain tissue. The degree of staining correlates with the distinct potassium content of infracted and non-infarcted brain areas. The aim of the present study was to prove that potassium staining technique is a reliable method for localization of ischemic core on native whole hemisphere cryosections of stroke patients. Furthermore, potassium stained sections have been compared with appropriate postmortem MRI images of respective brains. Brains of stroke patients were removed within 24h after death and postmortem MRI scanning was performed. Horizontal cryosections of frozen brains were taken and potassium staining was performed. Using the stained whole hemisphere sections as "map" tissue sampling has been made in order to determine water and potassium content. Potassium content of infarcted samples was significantly decreased in comparison with intact regions (0.7346+/-0.2142 mg/L and 1.928+/-0.447 mg/L, respectively, p<0.01) (mean values+/-SD). Water content of affected areas (expressed in percents) has been found to be above non-infarcted regions (81.657%+/-4.07 and 72.96%+/-6.37, respectively, p<0.01). According to our results the potassium staining method of human whole hemisphere brain sections reliably differentiates focal ischemic areas from intact brain regions. In conclusion, the postmortem examination of ischemic brain could be started with making the potassium map of infarcted whole hemisphere cryosections providing guidance for targeted tissue sampling and base of comparison for further examinations.
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Affiliation(s)
- László Csiba
- Department of Neurology, University of Debrecen Medical and Health Science Center, Móricz Zsigmond Street 22, Debrecen, H-4032, Hungary.
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Nagamoto-Combs K, Morecraft RJ, Darling WG, Combs CK. Long-term gliosis and molecular changes in the cervical spinal cord of the rhesus monkey after traumatic brain injury. J Neurotrauma 2010; 27:565-85. [PMID: 20030560 DOI: 10.1089/neu.2009.0966] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recovery of fine motor skills after traumatic brain injury (TBI) is variable, with some patients showing progressive improvements over time while others show poor recovery. We therefore studied possible cellular mechanisms accompanying the recovery process in a non-human primate model system, in which the lateral frontal motor cortex areas controlling the preferred upper limb were unilaterally lesioned, and the animals eventually regained fine hand motor function. Immunohistochemical staining of the cervical spinal cord, the site of compensatory sprouting and degeneration of corticospinal axons, showed profound increases in immunoreactivities for major histocompatibility complex class II molecule (MHC-II) and extracellular signal-regulated kinases (ERK1/2) up to 12 months post lesion, particularly within the lateral corticospinal tract (LCST). Double immunostaining demonstrated that phosphorylated ERK1/2 colocalized within the MCH-II + microglia, suggesting a trophic role of long-term microglia activation after TBI at the site of compensatory sprouting. Active sprouting was observed in the LCST as well as in the spinal gray matter of the lesioned animals, as illustrated by increases in growth associated protein 43. Upregulation of Nogo receptor and glutamate transporter expression was also observed in this region after TBI, suggesting possible mechanisms for controlling aberrant sprouting and/or synaptic formation en route and interstitial glutamate concentration changes at the site of axon degeneration, respectively. Taken together, these changes in the non-human primate spinal cord support a long-term trophic/tropic role for reactive microglia, in particular, during functional and structural recovery after TBI.
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Affiliation(s)
- Kumi Nagamoto-Combs
- Department of Anatomy and Cell Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58202, USA
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Cramer SC, Fitzpatrick C, Warren M, Hill MD, Brown D, Whitaker L, Ryckborst KJ, Plon L. The beta-hCG+erythropoietin in acute stroke (BETAS) study: a 3-center, single-dose, open-label, noncontrolled, phase IIa safety trial. Stroke 2010; 41:927-31. [PMID: 20203320 DOI: 10.1161/strokeaha.109.574343] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Animal data suggest the use of beta-human chorionic gonadotropin followed by erythropoietin to promote brain repair after stroke. The current study directly translated these results by evaluating safety of this sequential growth factor therapy through a 3-center, single-dose, open-label, noncontrolled, Phase IIa trial. METHODS Patients with ischemic stroke 24 to 48 hours old and National Institutes of Health Stroke Scale score of 6 to 24 started a 9-day course of beta-human chorionic gonadotropin (once daily on Days 1, 3, and 5 of study participation) followed by erythropoietin (once daily on Days 7, 8, and 9 of study participation). This study also evaluated performance of serially measured domain-specific end points. RESULTS A total of 15 patients were enrolled. Two deaths occurred, neither related to study medications. No safety concerns were noted among clinical or laboratory measures, including screening for deep vein thrombosis and serial measures of serum hemoglobin. In several instances, domain-specific end points provided greater insight into impairments as compared with global outcome measures. CONCLUSIONS Results support the safety of this sequential, 2-growth factor therapy initiated 24 to 48 hours after stroke onset.
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Affiliation(s)
- Steven C Cramer
- University of California, Irvine Medical Center, 101 The City Drive South, Building 53, Room 203, Orange, CA 92868-4280, USA.
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Abstract
Brain plasticity describes the potential of the organ for adaptive changes involved in various phenomena in health and disease. A substantial amount of experimental evidence, received in animal and cell models, shows that a cascade of plastic changes at the molecular, cellular, and tissue levels, is initiated in different regions of the postischemic brain. Underlying mechanisms include neurochemical alterations, functional changes in excitatory and inhibitory synapses, axonal and dendritic sprouting, and reorganization of sensory and motor central maps. Multiple lines of evidence indicate numerous points in which the process of postischemic recovery may be influenced with the aim to restore the full capacity of the brain tissue injured by an ischemic episode.
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Affiliation(s)
- Galyna G Skibo
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine
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Mingmalairak S, Tohda M, Murakami Y, Matsumoto K. Possible Involvement of Signal Transducers and Activators of Transcription 3 System on Depression in the Model Mice Brain. Biol Pharm Bull 2010; 33:636-40. [DOI: 10.1248/bpb.33.636] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Salin Mingmalairak
- Division of Medicinal Pharmacology, Institute of Natural Medicine, University of Toyama
| | - Michihisa Tohda
- Division of Medicinal Pharmacology, Institute of Natural Medicine, University of Toyama
| | - Yukihisa Murakami
- Division of Medicinal Pharmacology, Institute of Natural Medicine, University of Toyama
| | - Kinzo Matsumoto
- Division of Medicinal Pharmacology, Institute of Natural Medicine, University of Toyama
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Ende-Henningsen B, Henningsen H. Neurobiologische Grundlagen der Plastizität des Nervensystems. NeuroRehabilitation 2010. [DOI: 10.1007/978-3-642-12915-5_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Blizzard CA, King AE, Haas MA, O'Toole DA, Vickers JC, Dickson TC. Axonal shearing in mature cortical neurons induces attempted regeneration and the reestablishment of neurite polarity. Brain Res 2009; 1300:24-36. [PMID: 19715682 DOI: 10.1016/j.brainres.2009.08.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 08/17/2009] [Accepted: 08/18/2009] [Indexed: 12/17/2022]
Abstract
While functional recovery after injury is limited, it has become evident that the mature central nervous system does retain some ability to regenerate. This study investigated the intrinsic capacity of relatively mature cortical neurons (21 days in vitro) to respond to axonal loss. Neurons, growing as clusters on poly-L-lysine, were completely sheared of axons through chemical and mechanical disruption and transferred to either an intact astrocyte monolayer or a substrate of poly-L-lysine. Injured neurons exhibited a regenerative sprouting response that was independent of neuronal cell division or neural progenitors, as demonstrated by negative bromodeoxyuridine (BrdU) and the neuronal precursor intermediate filament nestin, labeling. At 24 h after injury, neurons had extended appropriately polarized neurites, demonstrated by compartmentalized microtubule-associated proteins MAP2 and tau immunolabeling. Newly sprouting axons were tipped by growth cones; however, growth cones on the tips of sprouting axons (mean area, 26.32 +/- 2.20 microm) were significantly (p<0.05) smaller than their developmental counterparts (mean area, 48.64 +/- 5.9 microm), independent of substrate. Furthermore, live imaging indicated that regenerating neurons exhibited distinct axonal dynamics, with a significant (p<0.05) reduction (70%) in pausing, considered vital for interstitial branching and pathfinding, relative to developmental growth cones. This study indicates that mature cultured cortical pyramidal and interneurons have the intrinsic potential to survive, extend processes, and reestablish neurite polarity following significant physical damage. These results may aid in defining the cellular basis of neuronal structural plasticity and defining the role of astrocyte reactivity in the response to trauma.
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Affiliation(s)
- Catherine A Blizzard
- Wicking Dementia Research and Education Centre and NeuroRepair Group, Menzies Research Institute, University of Tasmania, Private Bag 29, Hobart, Tasmania, Australia 7000
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Murphy TH, Corbett D. Plasticity during stroke recovery: from synapse to behaviour. Nat Rev Neurosci 2009; 10:861-72. [PMID: 19888284 DOI: 10.1038/nrn2735] [Citation(s) in RCA: 1246] [Impact Index Per Article: 83.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Reductions in blood flow to the brain of sufficient duration and extent lead to stroke, which results in damage to neuronal networks and the impairment of sensation, movement or cognition. Evidence from animal models suggests that a time-limited window of neuroplasticity opens following a stroke, during which the greatest gains in recovery occur. Plasticity mechanisms include activity-dependent rewiring and synapse strengthening. The challenge for improving stroke recovery is to understand how to optimally engage and modify surviving neuronal networks, to provide new response strategies that compensate for tissue lost to injury.
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Affiliation(s)
- Timothy H Murphy
- Kinsmen Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada.
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Madhavan L, Collier TJ. A synergistic approach for neural repair: cell transplantation and induction of endogenous precursor cell activity. Neuropharmacology 2009; 58:835-44. [PMID: 19853620 DOI: 10.1016/j.neuropharm.2009.10.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 10/12/2009] [Accepted: 10/15/2009] [Indexed: 12/11/2022]
Abstract
Stem cell research offers enormous potential for treating many diseases of the nervous system. At present, therapeutic strategies in stem cell research segregate into two approaches: cell transplantation or endogenous cell stimulation. Realistically, future cell therapies will most likely involve a combination of these two approaches, a theme of our current research. Here, we propose that there exists a 'synergy' between exogenous (transplanted) and endogenous stem cell actions that can be utilized to achieve therapeutic ends. Elucidating mechanisms underlying this exogenous-endogenous stem cell synergism may lead to the development of optimal cell therapies for neural disorders.
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Affiliation(s)
- Lalitha Madhavan
- Department of Neurology, University of Cincinnati, Cincinnati, OH 45267, USA.
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Eiden LE, Samal B, Gerdin MJ, Mustafa T, Vaudry D, Stroth N. Discovery of pituitary adenylate cyclase-activating polypeptide-regulated genes through microarray analyses in cell culture and in vivo. Ann N Y Acad Sci 2009; 1144:6-20. [PMID: 19076358 DOI: 10.1196/annals.1418.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an evolutionarily well conserved neuropeptide with multiple functions in the nervous, endocrine, and immune systems. PACAP provides neuroprotection from ischemia and toxin exposure, is anti-inflammatory in gastric inflammatory disease and sepsis, controls proliferative signaling pathways involved in neural cell transformation, and modulates glucohomeostasis. PACAP-based, disease-targeted therapeutics might thus be both effective and benign, enhancing homeostatic responses to behavioral, metabolic, oncogenic, and inflammatory stressors. PACAP signal transduction employs synergistic regulation of calcium and cyclic adenosine monophosphate (cAMP), and noncanonical activation of both calcium- and cAMP-dependent processes. Pharmacological activation of PACAP signaling should consequently have highly specific effects even in vivo. Here, a combined cellular biochemical, pharmacologic, transcriptomic, and bioinformatic approach to understanding PACAP signal transduction by identifying PACAP target genes with oligonucleotide- and cDNA-based microarray is described. Calcium- and cAMP-dependent PACAP signaling pathways for regulation of genes encoding proteins required for neuritogenesis, changes in cell morphology, and cell survival have been traced in PC12 cells. Pharmacological experiments have linked gene expression to cell physiological responses in this system, in which gene silencing can also be employed to confirm the functional significance of induction of specific transcripts. Differential transcriptional responses to metabolic, ischemic, and other stressors in wild type compared to PACAP-deficient mice establish in principle which PACAP-responsive transcripts in culture are PACAP-dependent in vivo. Bioinformatic approaches aid in creating a pipeline for identifying neuropeptide-regulated genes, validating their cellular functions, and defining their expression in the context of neuropeptide signaling physiology, required for discovery of new targets for drug action.
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Affiliation(s)
- Lee E Eiden
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, NIMH-IRP, NIH, Bethesda, MD 20892, USA.
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Ruff RL, McKerracher L, Selzer ME. Repair and Neurorehabilitation Strategies for Spinal Cord Injury. Ann N Y Acad Sci 2008; 1142:1-20. [DOI: 10.1196/annals.1444.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Qin H, Niyongere SA, Lee SJ, Baker BJ, Benveniste EN. Expression and functional significance of SOCS-1 and SOCS-3 in astrocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:3167-76. [PMID: 18713987 PMCID: PMC2836124 DOI: 10.4049/jimmunol.181.5.3167] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Astrocytes play a number of important physiological roles in CNS homeostasis. Inflammation stimulates astrocytes to secrete cytokines and chemokines that guide macrophages/microglia and T cells to sites of injury/inflammation. Herein, we describe how these processes are controlled by the suppressor of cytokine signaling (SOCS) proteins, a family of proteins that negatively regulate adaptive and innate immune responses. In this study, we describe that the immunomodulatory cytokine IFN-beta induces SOCS-1 and SOCS-3 expression in primary astrocytes at the transcriptional level. SOCS-1 and SOCS-3 transcriptional activity is induced by IFN-beta through IFN-gamma activation site (GAS) elements within their promoters. Studies in STAT-1alpha-deficient astrocytes indicate that STAT-1alpha is required for IFN-beta-induced SOCS-1 expression, while STAT-3 small interfering RNA studies demonstrate that IFN-beta-induced SOCS-3 expression relies on STAT-3 activation. Specific small interfering RNA inhibition of IFN-beta-inducible SOCS-1 and SOCS-3 in astrocytes enhances their proinflammatory responses to IFN-beta stimulation, such as heightened expression of the chemokines CCL2 (MCP-1), CCL3 (MIP-1alpha), CCL4 (MIP-1beta), CCL5 (RANTES), and CXCL10 (IP-10), and promoting chemotaxis of macrophages and CD4(+) T cells. These results indicate that IFN-beta induces SOCS-1 and SOCS-3 in primary astrocytes to attenuate its own chemokine-related inflammation in the CNS.
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Affiliation(s)
- Hongwei Qin
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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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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45
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Cramer SC. Repairing the human brain after stroke: I. Mechanisms of spontaneous recovery. Ann Neurol 2008; 63:272-87. [PMID: 18383072 DOI: 10.1002/ana.21393] [Citation(s) in RCA: 538] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Stroke remains a leading cause of adult disability. Some degree of spontaneous behavioral recovery is usually seen in the weeks after stroke onset. Variability in recovery is substantial across human patients. Some principles have emerged; for example, recovery occurs slowest in those destined to have less successful outcomes. Animal studies have extended these observations, providing insight into a broad range of underlying molecular and physiological events. Brain mapping studies in human patients have provided observations at the systems level that often parallel findings in animals. In general, the best outcomes are associated with the greatest return toward the normal state of brain functional organization. Reorganization of surviving central nervous system elements supports behavioral recovery, for example, through changes in interhemispheric lateralization, activity of association cortices linked to injured zones, and organization of cortical representational maps. A number of factors influence events supporting stroke recovery, such as demographics, behavioral experience, and perhaps genetics. Such measures gain importance when viewed as covariates in therapeutic trials of restorative agents that target stroke recovery.
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Affiliation(s)
- Steven C Cramer
- Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, Irvine, CA 92868-4280, USA.
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Hossmann KA, Traystman RJ. Cerebral blood flow and the ischemic penumbra. HANDBOOK OF CLINICAL NEUROLOGY 2008; 92:67-92. [PMID: 18790270 DOI: 10.1016/s0072-9752(08)01904-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Shenkar R, Shi C, Check IJ, Lipton HL, Awad IA. Concepts and hypotheses: inflammatory hypothesis in the pathogenesis of cerebral cavernous malformations. Neurosurgery 2007; 61:693-702; discussion 702-3. [PMID: 17986930 DOI: 10.1227/01.neu.0000298897.38979.07] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Cerebral cavernous malformations (CCMs) affect more than one million Americans, predisposing them to a lifetime risk of hemorrhagic stroke and epilepsy. A potential role of the immune response in this disease has not been postulated previously but is compelling given the unique antigenic milieu of CCM lesions with sequestered thrombi and a leaky blood-brain barrier and the numerous examples of immune modulation of angiogenesis in other disease states. The objective of this article is to reveal novel observations about apparent immune responses in CCM lesions excised from human patients and to outline the potential pathobiological significance of these observations, specific hypotheses for future research, and potential clinical implications. METHODS We reviewed data from differential gene expression revealing several immunoglobulin and other related genes markedly upregulated within human CCM lesions. Other observations are presented revealing infiltration of antibody-producing B lymphocytes and plasma cells in CCM lesions. We also present recent data demonstrating fivefold enrichment of gamma globulin to albumin ratio in a human lesion compared with serum from the same patient and oligoclonality of IgG in four of five CCM lesions, but not in paired sera from the same patients or in control specimens. RESULTS We describe ongoing research aiming to characterize cellular and humoral components of the immune response in CCMs and initiating investigation into its clonality by isoelectric focusing on the predominant immunoglobulin isotypes isolated from the lesion, in comparison to the patient's serum, and by the distribution of lengths of complementary-determining region 3 of the immunoglobulin heavy chain genes in messenger ribonucleic acid isolated from lesions and from pooled plasma cells and B cells laser captured from CCMs in comparison to peripheral lymphocytes from the blood of the same patients. CONCLUSION Immune response could play a role in or represent a potential marker of CCM lesion proliferation and hemorrhage or could otherwise contribute to lesion phenotype. The ongoing studies will generate preliminary data for future research aimed at comparing the immune response in quiescent versus clinically aggressive CCM lesions. An oligoclonal immune response shown in this research would stimulate future experiments to identify autoimmune or extrinsic antigenic triggers involved in CCM disease.
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Affiliation(s)
- Robert Shenkar
- Department of Neurological Surgery, Evanston Northwestern Healthcare, Evanston, IL 60201, USA.
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Zhang ZY, Zhang Z, Fauser U, Schluesener HJ. Global hypomethylation defines a sub-population of reactive microglia/macrophages in experimental traumatic brain injury. Neurosci Lett 2007; 429:1-6. [DOI: 10.1016/j.neulet.2007.09.061] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 09/11/2007] [Accepted: 09/21/2007] [Indexed: 01/05/2023]
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Blizzard CA, Haas MA, Vickers JC, Dickson TC. Cellular dynamics underlying regeneration of damaged axons differs from initial axon development. Eur J Neurosci 2007; 26:1100-8. [PMID: 17767489 DOI: 10.1111/j.1460-9568.2007.05750.x] [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: 01/23/2023]
Abstract
While long-distance regeneration may be limited in mammalian species, it is becoming apparent that damaged mature neurons retain some capacity for attempted regeneration and that the adult CNS is not entirely inhibitory to axon growth. Our investigations show that there are critical intrinsic features of postinjury axonal regeneration that differ from initial axon development, and that these distinct differences may account for the limited and inappropriate regenerative response that currently characterizes the mature CNS. We compared the neurochemical and dynamic characteristics of developing axons to relatively mature regenerating axons, utilizing an in vitro model of axonal transection to long-term cultured rat cortical neurons. Immunolabelling studies revealed that regenerating and developing axons have a similar localization of cytoskeletal proteins, but the tips of regenerating axons, although morphologically similar, were smaller with reduced fillopodial extension, relative to developmental growth cones. Live imaging demonstrated that regenerating axons exhibited significantly less outgrowth than developmental neurites. Furthermore, growth cones of regenerating axons had a significant reduction in pausing, considered vital for interstitial branching and pathfinding, than did developmental growth cones. In addition, unlike developing axons, the regenerating axons were unresponsive to the growth factors BDNF and GDNF. Thus, although similar in their cytoskeletal composition, the growth cones of regenerative sprouts differed from their developmental counterparts in their size, their dynamic behaviour and their ability to respond to critical growth factors. These intrinsic differences may account for the inability of post-traumatic locally sprouting axons to make accurate pathway decisions and successfully respond to trauma.
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Affiliation(s)
- C A Blizzard
- NeuroRepair Group, Menzies Research Institute, University of Tasmania, Private Bag 29, Hobart, Tasmania, Australia 7000
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Rodríguez-González R, Hurtado O, Sobrino T, Castillo J. Neuroplasticity and cellular therapy in cerebral infarction. Cerebrovasc Dis 2007; 24 Suppl 1:167-80. [PMID: 17971653 DOI: 10.1159/000107393] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Stroke is the second to third most common cause of death in adults, and more than a third of people who survive a stroke will have severe disability. Therapeutic options currently centre on fibrinolytic treatment, but its limitations restrict use to a small proportion of patients. Although a wide range of neuroprotective substances has been effective in experimental models, they have repeatedly failed in clinical trials because of toxicity or loss of effectiveness. Recent strategies based on neuroplasticity and cellular therapy have shown significant efficacy in improving functional recovery in experimental models, although further study is still necessary to clarify how the brain responds to ischaemic damage and is able to reorganize itself in the long term. Although steps must still be taken to ensure the safety and feasibility of treatments based on neuroplasticity and cellular therapy, neurorepair strategies provide promising future therapeutic options for stroke.
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Affiliation(s)
- Raquel Rodríguez-González
- Clinical Neuroscience Research Laboratory, Division of Vascular Neurology, Department of Neurology, Hospital Clínico Universitario, University of Santiago de Compostela, Santiago de Compostela, Spain
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