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Wallis GJ, Bell LA, Wagner JN, Buxton L, Balachandar L, Wilcox KS. Reactive microglia fail to respond to environmental damage signals in a viral-induced mouse model of temporal lobe epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.06.583768. [PMID: 38558969 PMCID: PMC10979929 DOI: 10.1101/2024.03.06.583768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Microglia are highly adaptable innate immune cells that rapidly respond to damage signals in the brain through adoption of a reactive phenotype and production of defensive inflammatory cytokines. Microglia express a distinct transcriptome, encoding receptors that allow them to dynamically respond to pathogens, damage signals, and cellular debris. Expression of one such receptor, the microglia-specific purinergic receptor P2ry12, is known to be downregulated in reactive microglia. Here, we explore the microglial response to purinergic damage signals in reactive microglia in the TMEV mouse model of viral brain infection and temporal lobe epilepsy. Using two-photon calcium imaging in acute hippocampal brain slices, we found that the ability of microglia to detect damage signals, engage calcium signaling pathways, and chemoattract towards laser-induced tissue damage was dramatically reduced during the peak period of seizures, cytokine production, and infection. Using combined RNAscope in situ hybridization and immunohistochemistry, we found that during this same stage of heightened infection and seizures, microglial P2ry12 expression was reduced, while the pro-inflammatory cytokine TNF-a expression was upregulated in microglia, suggesting that the depressed ability of microglia to respond to new damage signals via P2ry12 occurs during the time when local elevated cytokine production contributes to seizure generation following infection. Therefore, changes in microglial purinergic receptors during infection likely limit the ability of reactive microglia to respond to new threats in the CNS and locally contain the scale of the innate immune response in the brain.
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Affiliation(s)
- Glenna J Wallis
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Laura A Bell
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, 80904
| | - John N Wagner
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Lauren Buxton
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Lakshmini Balachandar
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Karen S Wilcox
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, 80904
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2
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Collyer E, Boyle BR, Gomez-Galvez Y, Iacovitti L, Blanco-Suarez E. Absence of chordin-like 1 aids motor recovery in a mouse model of stroke. Exp Neurol 2023; 370:114548. [PMID: 37769794 DOI: 10.1016/j.expneurol.2023.114548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/06/2023] [Accepted: 09/24/2023] [Indexed: 10/03/2023]
Abstract
Chordin-like 1 (Chrdl1) is an astrocyte-secreted protein that regulates synaptic maturation, and limits plasticity via GluA2-containing AMPA receptors (AMPARs). It was demonstrated that Chrdl1 expression is very heterogeneous throughout the brain, and it is enriched in astrocytes in cortical layers 2/3, with peak expression in the visual cortex at postnatal day 14. In response to ischemic stroke, Chrdl1 is upregulated during the acute and sub-acute phases in the peri-infarct region, potentially hindering recovery after stroke. Here, we used photothrombosis to model ischemic stroke in the motor cortex of adult male and female mice. In this study, we demonstrate that elimination of Chrdl1 in a global knock-out mouse reduces apoptotic cell death at early post-stroke stages and prevents ischemia-driven synaptic loss of AMPA receptors at later time points, all contributing to faster motor recovery. This suggests that synapse-regulating astrocyte-secreted proteins such as Chrdl1 have therapeutic potential to aid functional recovery after an ischemic injury.
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Affiliation(s)
- Eileen Collyer
- Department of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Vickie & Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Bridget R Boyle
- Department of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Vickie & Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Yolanda Gomez-Galvez
- Department of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Vickie & Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; The Joseph and Marie Field Cerebrovascular Research Laboratory, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Lorraine Iacovitti
- Department of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Vickie & Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Department of Neurological Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; The Joseph and Marie Field Cerebrovascular Research Laboratory, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Elena Blanco-Suarez
- Department of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Vickie & Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA; Department of Neurological Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
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3
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Kodali M, Madhu LN, Reger RL, Milutinovic B, Upadhya R, Attaluri S, Shuai B, Shankar G, Shetty AK. A single intranasal dose of human mesenchymal stem cell-derived extracellular vesicles after traumatic brain injury eases neurogenesis decline, synapse loss, and BDNF-ERK-CREB signaling. Front Mol Neurosci 2023; 16:1185883. [PMID: 37284464 PMCID: PMC10239975 DOI: 10.3389/fnmol.2023.1185883] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/28/2023] [Indexed: 06/08/2023] Open
Abstract
An optimal intranasal (IN) dose of human mesenchymal stem cell-derived extracellular vesicles (hMSC-EVs), 90 min post-traumatic brain injury (TBI), has been reported to prevent the evolution of acute neuroinflammation into chronic neuroinflammation resulting in the alleviation of long-term cognitive and mood impairments. Since hippocampal neurogenesis decline and synapse loss contribute to TBI-induced long-term cognitive and mood dysfunction, this study investigated whether hMSC-EV treatment after TBI can prevent hippocampal neurogenesis decline and synapse loss in the chronic phase of TBI. C57BL6 mice undergoing unilateral controlled cortical impact injury (CCI) received a single IN administration of different doses of EVs or the vehicle at 90 min post-TBI. Quantifying neurogenesis in the subgranular zone-granule cell layer (SGZ-GCL) through 5'-bromodeoxyuridine and neuron-specific nuclear antigen double labeling at ~2 months post-TBI revealed decreased neurogenesis in TBI mice receiving vehicle. However, in TBI mice receiving EVs (12.8 and 25.6 × 109 EVs), the extent of neurogenesis was matched to naive control levels. A similar trend of decreased neurogenesis was seen when doublecortin-positive newly generated neurons were quantified in the SGZ-GCL at ~3 months post-TBI. The above doses of EVs treatment after TBI also reduced the loss of pre-and post-synaptic marker proteins in the hippocampus and the somatosensory cortex. Moreover, at 48 h post-treatment, brain-derived neurotrophic factor (BDNF), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2), and phosphorylated cyclic AMP response-element binding protein (p-CREB) levels were downregulated in TBI mice receiving the vehicle but were closer to naïve control levels in TBI mice receiving above doses of hMSC-EVs. Notably, improved BDNF concentration observed in TBI mice receiving hMSC-EVs in the acute phase was sustained in the chronic phase of TBI. Thus, a single IN dose of hMSC-EVs at 90 min post-TBI can ease TBI-induced declines in the BDNF-ERK-CREB signaling, hippocampal neurogenesis, and synapses.
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Schwarz K, Schmitz F. Synapse Dysfunctions in Multiple Sclerosis. Int J Mol Sci 2023; 24:ijms24021639. [PMID: 36675155 PMCID: PMC9862173 DOI: 10.3390/ijms24021639] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system (CNS) affecting nearly three million humans worldwide. In MS, cells of an auto-reactive immune system invade the brain and cause neuroinflammation. Neuroinflammation triggers a complex, multi-faceted harmful process not only in the white matter but also in the grey matter of the brain. In the grey matter, neuroinflammation causes synapse dysfunctions. Synapse dysfunctions in MS occur early and independent from white matter demyelination and are likely correlates of cognitive and mental symptoms in MS. Disturbed synapse/glia interactions and elevated neuroinflammatory signals play a central role. Glutamatergic excitotoxic synapse damage emerges as a major mechanism. We review synapse/glia communication under normal conditions and summarize how this communication becomes malfunctional during neuroinflammation in MS. We discuss mechanisms of how disturbed glia/synapse communication can lead to synapse dysfunctions, signaling dysbalance, and neurodegeneration in MS.
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Gonzalez A, Hammock EAD. Oxytocin and microglia in the development of social behaviour. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210059. [PMID: 35858111 PMCID: PMC9272152 DOI: 10.1098/rstb.2021.0059] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/18/2022] [Indexed: 08/31/2023] Open
Abstract
Oxytocin is a well-established regulator of social behaviour. Microglia, the resident immune cells of the central nervous system, regulate brain development and maintenance in health and disease. Oxytocin and microglia interact: microglia appear to regulate the oxytocin system and are, in turn, regulated by oxytocin, which appears to have anti-inflammatory effects. Both microglia and oxytocin are regulated in sex-specific ways. Oxytocin and microglia may work together to promote experience-dependent circuit refinement through multiple developmental-sensitive periods contributing to individual differences in social behaviour. This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.
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Affiliation(s)
- Alicia Gonzalez
- Department of Psychology and Program in Neuroscience, Florida State University, 1107 West Call Street, Tallahassee, FL 32306, USA
| | - Elizabeth A. D. Hammock
- Department of Psychology and Program in Neuroscience, Florida State University, 1107 West Call Street, Tallahassee, FL 32306, USA
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Nicoletti VG, Pajer K, Calcagno D, Pajenda G, Nógrádi A. The Role of Metals in the Neuroregenerative Action of BDNF, GDNF, NGF and Other Neurotrophic Factors. Biomolecules 2022; 12:biom12081015. [PMID: 35892326 PMCID: PMC9330237 DOI: 10.3390/biom12081015] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 12/14/2022] Open
Abstract
Mature neurotrophic factors and their propeptides play key roles ranging from the regulation of neuronal growth and differentiation to prominent participation in neuronal survival and recovery after injury. Their signaling pathways sculpture neuronal circuits during brain development and regulate adaptive neuroplasticity. In addition, neurotrophic factors provide trophic support for damaged neurons, giving them a greater capacity to survive and maintain their potential to regenerate their axons. Therefore, the modulation of these factors can be a valuable target for treating or preventing neurologic disorders and age-dependent cognitive decline. Neuroregenerative medicine can take great advantage by the deepening of our knowledge on the molecular mechanisms underlying the properties of neurotrophic factors. It is indeed an intriguing topic that a significant interplay between neurotrophic factors and various metals can modulate the outcome of neuronal recovery. This review is particularly focused on the roles of GDNF, BDNF and NGF in motoneuron survival and recovery from injuries and evaluates the therapeutic potential of various neurotrophic factors in neuronal regeneration. The key role of metal homeostasis/dyshomeostasis and metal interaction with neurotrophic factors on neuronal pathophysiology is also highlighted as a novel mechanism and potential target for neuronal recovery. The progress in mechanistic studies in the field of neurotrophic factor-mediated neuroprotection and neural regeneration, aiming at a complete understanding of integrated pathways, offers possibilities for the development of novel neuroregenerative therapeutic approaches.
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Affiliation(s)
- Vincenzo Giuseppe Nicoletti
- Department of Biomedical and Biotechnological Sciences (BIOMETEC), Section of Medical Biochemistry, University of Catania, 95124 Catania, Italy; (V.G.N.); (D.C.)
| | - Krisztián Pajer
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, 6720 Szeged, Hungary;
| | - Damiano Calcagno
- Department of Biomedical and Biotechnological Sciences (BIOMETEC), Section of Medical Biochemistry, University of Catania, 95124 Catania, Italy; (V.G.N.); (D.C.)
| | - Gholam Pajenda
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Research Centre for Traumatology of the Austrian Workers, 1200 Vienna, Austria;
- Department for Trauma Surgery, Medical University Vienna, 1090 Vienna, Austria
| | - Antal Nógrádi
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, 6720 Szeged, Hungary;
- Correspondence: ; Tel.: +36-6-234-2855
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7
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Edonerpic maleate regulates glutamate receptors through CRMP2- and Arc-mediated mechanisms in response to brain trauma. Cell Death Dis 2022; 8:95. [PMID: 35246523 PMCID: PMC8897457 DOI: 10.1038/s41420-022-00901-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 11/09/2022]
Abstract
Dysfunction of ionotropic glutamate receptors (iGluRs) is a key molecular mechanism of excitotoxic neuronal injury following traumatic brain injury (TBI). Edonerpic maleate is a low molecular-weight compound that was screened as a candidate neuroprotective agent. In this study, we investigated its effects on TBI and GluRs signaling. Traumatic neuronal injury (TNI) induced by scratch followed by glutamate treatment was performed to mimic TBI in vitro. Edonerpic maleate at 1 and 10 μM exerted protective activity when it was added within 2 h following injury. The protective activities were also confirmed by the reduction of lipid peroxidation and oxidative stress. In addition, edonerpic maleate inhibited the expression of surface NR2B, total GluR1, and surface GluR1, and mitigated the intracellular Ca2+ responses following injury in vitro. Western blot analysis showed that edonerpic maleate reduced the cleavage of collapsing response mediator protein 2 (CRMP2), but increased the expression of postsynaptic protein Arc. By using gene overexpression and silencing technologies, CRMP2 was overexpressed and Arc was knockdown in cortical neurons. The results showed that the effect of edonerpic maleate on NMDA receptor expression was mediated by CRMP2, whereas the edonerpic maleate-induced AMPA receptor regulation was dependent on Arc activation. In in vivo TBI model, 30 mg/kg edonerpic maleate alleviated the TBI-induced brain edema, neuronal loss, and microglial activation, with no effect on locomotor function at 24 h. However, edonerpic maleate improves long-term neurological function after TBI. Furthermore, edonerpic maleate inhibited CRMP2 cleavage but increased Arc activation in vivo. In summary, our results identify edonerpic maleate as a clinically potent small compound with which to attenuate TBI-related brain damage through regulating GluRs signaling.
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8
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Olsen CM, Corrigan JD. Does Traumatic Brain Injury Cause Risky Substance Use or Substance Use Disorder? Biol Psychiatry 2022; 91:421-437. [PMID: 34561027 PMCID: PMC8776913 DOI: 10.1016/j.biopsych.2021.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/07/2021] [Accepted: 07/12/2021] [Indexed: 01/22/2023]
Abstract
There is a high co-occurrence of risky substance use among adults with traumatic brain injury (TBI), although it is unknown if the neurologic sequelae of TBI can promote this behavior. We propose that to conclude that TBI can cause risky substance use, it must be determined that TBI precedes risky substance use, that confounders with the potential to increase the likelihood of both TBI and risky substance use must be ruled out, and that there must be a plausible mechanism of action. In this review, we address these factors by providing an overview of key clinical and preclinical studies and list plausible mechanisms by which TBI could increase risky substance use. Human and animal studies have identified an association between TBI and risky substance use, although the strength of this association varies. Factors that may limit detection of this relationship include differential variability due to substance, sex, age of injury, and confounders that may influence the likelihood of both TBI and risky substance use. We propose possible mechanisms by which TBI could increase substance use that include damage-associated neuroplasticity, chronic changes in neuroimmune signaling, and TBI-associated alterations in brain networks.
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Affiliation(s)
- Christopher M Olsen
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin; Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
| | - John D Corrigan
- Department of Physical Medicine & Rehabilitation, Wexner Medical Center, The Ohio State University, Columbus, Ohio
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Chuang HW, Wang TY, Huang CC, Wei IH. Echinacoside exhibits antidepressant-like effects through AMPAR-Akt/ERK-mTOR pathway stimulation and BDNF expression in mice. Chin Med 2022; 17:9. [PMID: 34983570 PMCID: PMC8728918 DOI: 10.1186/s13020-021-00549-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/06/2021] [Indexed: 12/25/2022] Open
Abstract
Background Several natural products have been demonstrated to be effective in the treatment of depressive disorders. Echinacoside, a naturally occurring phenol extracted from Cistanche tubulosa, Echinacea angustifolia, and Cistanche spp, has a wide range of physiological effects, such as antioxidation, neuroprotection, anti-inflammatory, and immunoregulation, which are closely related to depression. In addition, echinacoside can activate protein kinase B (Akt), extracellular signal–regulated kinase (ERK), and brain-derived neurotrophic factor (BDNF) in the brain. A key downstream event of the Akt, ERK, and BDNF signaling pathways, namely mechanistic target of rapamycin (mTOR) signaling, plays a crucial role in generating an rapid antidepressant effect. Thus, echinacoside is a promising therapeutic agent for depression. However, research regarding the role of echinacoside in antidepressant effect and brain mTOR activation remains lacking. Materials and methods The forced swimming test and Western blot analysis in C57BL/6 mice was used to investigate the antidepressant-like activities of echinacoside and the underlying mechanism involved inα-amino3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)–Akt/ERK–mTOR pathway. Results We confirmed the suggestions by previous reports that echinacoside activates Akt/ERK signaling and further demonstrated that echinacoside could provide antidepressant-like effects in mice via the activation of AMPAR–Akt/ERK–mTOR pathway in the hippocampus. Conclusions To the best of our knowledge, our study is the first to reveal that echinacoside is a potential treatment for depressive disorders. Moreover, the present study suggests a mechanism for the neuroprotective effect of echinacoside. Supplementary Information The online version contains supplementary material available at 10.1186/s13020-021-00549-5.
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Affiliation(s)
- Han-Wen Chuang
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Tse-Yen Wang
- Department of Post-baccalaureate Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Chih-Chia Huang
- Tsaotun Psychiatric Center, Ministry of Health and Welfare, Nantou, Taiwan. .,Department of Psychiatry, China Medical University, Taichung, Taiwan. .,Department of Psychiatry, China Medical University Hospital, Taichung, Taiwan. .,Program in Translational Medicine, National Chung Hsing University, Taichung, Taiwan.
| | - I-Hua Wei
- Department of Anatomy, China Medical University, Taichung, Taiwan.
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Guan PP, Cao LL, Yang Y, Wang P. Calcium Ions Aggravate Alzheimer's Disease Through the Aberrant Activation of Neuronal Networks, Leading to Synaptic and Cognitive Deficits. Front Mol Neurosci 2021; 14:757515. [PMID: 34924952 PMCID: PMC8674839 DOI: 10.3389/fnmol.2021.757515] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/04/2021] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease that is characterized by the production and deposition of β-amyloid protein (Aβ) and hyperphosphorylated tau, leading to the formation of β-amyloid plaques (APs) and neurofibrillary tangles (NFTs). Although calcium ions (Ca2+) promote the formation of APs and NFTs, no systematic review of the mechanisms by which Ca2+ affects the development and progression of AD has been published. Therefore, the current review aimed to fill the gaps between elevated Ca2+ levels and the pathogenesis of AD. Specifically, we mainly focus on the molecular mechanisms by which Ca2+ affects the neuronal networks of neuroinflammation, neuronal injury, neurogenesis, neurotoxicity, neuroprotection, and autophagy. Furthermore, the roles of Ca2+ transporters located in the cell membrane, endoplasmic reticulum (ER), mitochondria and lysosome in mediating the effects of Ca2+ on activating neuronal networks that ultimately contribute to the development and progression of AD are discussed. Finally, the drug candidates derived from herbs used as food or seasoning in Chinese daily life are summarized to provide a theoretical basis for improving the clinical treatment of AD.
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Affiliation(s)
- Pei-Pei Guan
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Long-Long Cao
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yi Yang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Pu Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
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Watanabe J. Teaching Neuroimmunology to Undergraduate Students: Resource for Full Course or Modular Implementation. JOURNAL OF UNDERGRADUATE NEUROSCIENCE EDUCATION : JUNE : A PUBLICATION OF FUN, FACULTY FOR UNDERGRADUATE NEUROSCIENCE 2021; 19:A163-A184. [PMID: 34552435 PMCID: PMC8437358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Indexed: 06/13/2023]
Abstract
This paper describes a course I designed to teach neuroimmunology to undergraduate students. In this course I incorporated many active learning strategies to help make it a student-centered class, where they developed communication skills, while reading and analyzing primary literature articles. As the field of neuroimmunology is relatively new, most textbooks in the field approached the subject from the perspective of neurology and autoimmune diseases. Therefore, I used reading, analysis, and student-led presentation of primary papers in the classroom to not only develop critical thinking and application of the scientific method, but also oral communication skills. Other activities such as writing New York Times-style articles and literature review papers were employed to develop written communications skills. The goal of this article is to provide a reference tool for instructors trained in neuroscience to deploy an entire course on neuroimmunology or select a module or a single paper to incorporate into their existing course to offer students a taste for neuroimmunology.
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GluA2 overexpression in oligodendrocyte progenitors promotes postinjury oligodendrocyte regeneration. Cell Rep 2021; 35:109147. [PMID: 34010640 PMCID: PMC8185898 DOI: 10.1016/j.celrep.2021.109147] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 01/28/2020] [Accepted: 04/27/2021] [Indexed: 01/18/2023] Open
Abstract
Oligodendrocyte precursor cells (OPCs) are essential for developmental myelination and oligodendrocyte regeneration after CNS injury. These progenitors express calcium-permeable AMPA receptors (AMPARs) and form direct synapses with neurons throughout the CNS, but the roles of this signaling are unclear. To enable selective alteration of the properties of AMPARs in oligodendroglia, we generate mice that allow cell-specific overexpression of EGFP-GluA2 in vivo. In healthy conditions, OPC-specific GluA2 overexpression significantly increase their proliferation in an age-dependent manner but did not alter their rate of differentiation into oligodendrocytes. In contrast, after demyelinating brain injury in neonates or adults, higher GluA2 levels promote both OPC proliferation and oligodendrocyte regeneration, but do not prevent injury-induced initial cell loss. These findings indicate that AMPAR GluA2 content regulates the proliferative and regenerative behavior of adult OPCs, serving as a putative target for better myelin repair.
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Abbaszadeh F, Fakhri S, Khan H. Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals. Pharmacol Res 2020; 160:105069. [PMID: 32652198 DOI: 10.1016/j.phrs.2020.105069] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/28/2020] [Accepted: 07/03/2020] [Indexed: 12/11/2022]
Abstract
Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.
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Affiliation(s)
- Fatemeh Abbaszadeh
- Department of Neuroscience, Faculty of Advanced Technologies in Medical Sciences, Iran University of Medical Sciences, Tehran, Iran; Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sajad Fakhri
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6734667149, Iran.
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University Mardan, 23200, Pakistan.
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Ballinger- C, Anyagaligb O, Bernard J, Bierbower SM, Dupont-Ver EE, Ghoweri A, Greenhalgh A, Harrison D, Istas O, McNabb M, Saelinger C, Stanback A, Stanback M, Thibault O, Cooper RL. Effects of Bacterial Endotoxin (LPS) on Cardiac and Synaptic Function in Various Animal Models: Larval Drosophila, Crayfish, Crab and Rodent. ACTA ACUST UNITED AC 2019. [DOI: 10.3923/ijzr.2020.33.62] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Aurelian L, Balan I. GABA AR α2-activated neuroimmune signal controls binge drinking and impulsivity through regulation of the CCL2/CX3CL1 balance. Psychopharmacology (Berl) 2019; 236:3023-3043. [PMID: 31030249 DOI: 10.1007/s00213-019-05220-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/04/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Toll-like receptors (TLRs) are a family of innate immune system receptors that respond to pathogen-derived and tissue damage-related ligands and are increasingly recognized for their impact on homeostasis and its dysregulation in the nervous system. TLR signaling participates in brain injury and addiction, but its role in the alcohol-seeking behavior, which initiates alcohol drinking, is still poorly understood. In this review, we discuss our findings designed to elucidate the potential contribution of the activated TLR4 signal located in neurons, on impulsivity and the predisposition to initiate alcohol drinking (binge drinking). RESULTS Our findings indicate that the TLR4 signal is innately activated in neurons from alcohol-preferring subjects, identifying a genetic contribution to the regulation of impulsivity and the alcohol-seeking propensity. Signal activation is through the non-canonical, previously unknown, binding of TLR4 to the α2 subunit of the γ-aminobutyric 2 acid A receptor (GABAAR α2). Activation is sustained by the stress hormone corticotrophin-releasing factor (CRF) and additional still poorly recognized ligand/scaffold proteins. Focus is on the effect of TLR4 signal activation on the balance between pro- and anti-inflammatory chemokines [chemokine (C-C motif) ligand 2 (CCL2)/chemokine (C-X3-C motif) ligand 1 (CX3CL1)] and its effect on binge drinking. CONCLUSION The results are discussed within the context of current findings on the distinct activation and functions of TLR signals located in neurons, as opposed to immune cells. They indicate that the balance between pro- and anti-inflammatory TLR4 signaling plays a major role in binge drinking. These findings have major impact on future basic and translational research, including the development of potential therapeutic and preventative strategies.
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Affiliation(s)
- Laure Aurelian
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Stanford University School of Medicine OFDD, Stanford, CA, 94305, USA.
| | - Irina Balan
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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16
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Wang J, Zhang M, Guo Y, Hu H, Chen K. Quantification of surviving neurons after contusion, dislocation, and distraction spinal cord injuries using automated methods. J Exp Neurosci 2019; 13:1179069519869617. [PMID: 31456647 PMCID: PMC6702772 DOI: 10.1177/1179069519869617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 07/22/2019] [Indexed: 01/03/2023] Open
Abstract
This study proposes and validates an automated method for counting neurons in spinal cord injury (SCI) and then uses it to examine and compare the surviving cells in common types of SCI mechanisms. Moderate contusion, dislocation, and distraction SCIs were surgically induced in Sprague Dawley male rats (n = 6 for each type of injury). Their spinal cords were harvested 8 weeks post injury with 5 normal weight-matched rats. The spinal cords were cut, stained with anti-NeuN antibody and fluorescent Nissl, and imaged in the dorsal and ventral horns at various distances to the epicenter. Neurons in the images were automatically counted using an algorithm that was designed to filter non-soma-like objects based on morphological characteristics (size, solidity, circular pattern) and check the remaining objects for the double-stained nucleus/cell body features (brightness variation, brightness distribution, color). To validate the automated method, some of the images were randomly selected for manual counting. The number of surviving cells that were automatically measured by the algorithm was found to be correlated with the values that were manually measured by 2 observers (P < .001) with similar differences (P > .05). Neurons in the dorsal and ventral horns were reduced after the SCIs (P < .05). Dislocation and distraction, respectively, caused the most severe damage to the ventral horn neurons especially near the epicenter and the most extensive and uniform damage to the dorsal horn neurons (P < .05). Our method was proved to be reliable, which is suitable for studying different types of SCI.
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Affiliation(s)
- Jingchao Wang
- School of Biological Science and Medical Engineering, Beihang University (BUAA)-Yifu Science Hall, Beijing, China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University (BUAA), Beijing, China
| | - Meiyan Zhang
- School of Biological Science and Medical Engineering, Beihang University (BUAA)-Yifu Science Hall, Beijing, China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University (BUAA), Beijing, China
| | - Yue Guo
- School of Biological Science and Medical Engineering, Beihang University (BUAA)-Yifu Science Hall, Beijing, China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University (BUAA), Beijing, China
| | - Hai Hu
- School of Biological Science and Medical Engineering, Beihang University (BUAA)-Yifu Science Hall, Beijing, China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University (BUAA), Beijing, China
| | - Kinon Chen
- School of Biological Science and Medical Engineering, Beihang University (BUAA)-Yifu Science Hall, Beijing, China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University (BUAA), Beijing, China.,International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, BC, Canada
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17
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Farrell K, Houle JD. Systemic Inhibition of Soluble Tumor Necrosis Factor with XPro1595 Exacerbates a Post-Spinal Cord Injury Depressive Phenotype in Female Rats. J Neurotrauma 2019; 36:2964-2976. [PMID: 31064292 DOI: 10.1089/neu.2019.6438] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Spinal cord injury (SCI) is associated with a three-fold risk of major depressive disorder compared with the general population. Current antidepressant therapy is often not as effective in this patient population, suggesting the need for a more efficacious therapeutic target. The goal of this study was to elucidate the role of inflammatory cytokine tumor necrosis factor (TNF) in the dorsal raphe nucleus (DRN, the principle source of serotonin to the brain) in the development and possible treatment of depression after SCI. A depressive phenotype following moderate T9 contusion was identified in adult female rats using a battery of behavioral tests (forced swim test, sucrose preference test, novel object recognition test, open field locomotion, and social exploration). Data revealed two clusters of injured rats (58%) that exhibit increased immobility in the forced swim test, indicating depressive phenotype or a melancholic-depressive phenotype with concomitant decrease in sucrose preference. ElevatedTNF levels in the DRN of these two clusters correlated with increased immobility in the forced swim test. We then tested the efficacy of soluble TNF inhibition with XPro1595 treatment to prevent the depressive phenotype after SCI. Subcutaneous (s.c.) delivery of XPro1595 caused an exacerbation of depressive phenotype, with all treated clusters exhibiting increased forced swim immobility compared with saline-treated non-depressed rats. Intracerebroventricular (i.c.v.) administration of the drug did not prevent or enhance the development of depression after injury. These results suggest a complex role for TNF-based neuroinflammation in SCI-induced depression that needs to be further explored, perhaps in conjunction with a broader targeting of additional post-SCI inflammatory cytokines.
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Affiliation(s)
- Kaitlin Farrell
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - John D Houle
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, Pennsylvania
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18
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Wang W, Zhang LS, Zinsmaier AK, Patterson G, Leptich EJ, Shoemaker SL, Yatskievych TA, Gibboni R, Pace E, Luo H, Zhang J, Yang S, Bao S. Neuroinflammation mediates noise-induced synaptic imbalance and tinnitus in rodent models. PLoS Biol 2019; 17:e3000307. [PMID: 31211773 PMCID: PMC6581239 DOI: 10.1371/journal.pbio.3000307] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 05/16/2019] [Indexed: 12/20/2022] Open
Abstract
Hearing loss is a major risk factor for tinnitus, hyperacusis, and central auditory processing disorder. Although recent studies indicate that hearing loss causes neuroinflammation in the auditory pathway, the mechanisms underlying hearing loss–related pathologies are still poorly understood. We examined neuroinflammation in the auditory cortex following noise-induced hearing loss (NIHL) and its role in tinnitus in rodent models. Our results indicate that NIHL is associated with elevated expression of proinflammatory cytokines and microglial activation—two defining features of neuroinflammatory responses—in the primary auditory cortex (AI). Genetic knockout of tumor necrosis factor alpha (TNF-α) or pharmacologically blocking TNF-α expression prevented neuroinflammation and ameliorated the behavioral phenotype associated with tinnitus in mice with NIHL. Conversely, infusion of TNF-α into AI resulted in behavioral signs of tinnitus in both wild-type and TNF-α knockout mice with normal hearing. Pharmacological depletion of microglia also prevented tinnitus in mice with NIHL. At the synaptic level, the frequency of miniature excitatory synaptic currents (mEPSCs) increased and that of miniature inhibitory synaptic currents (mIPSCs) decreased in AI pyramidal neurons in animals with NIHL. This excitatory-to-inhibitory synaptic imbalance was completely prevented by pharmacological blockade of TNF-α expression. These results implicate neuroinflammation as a therapeutic target for treating tinnitus and other hearing loss–related disorders. Prolonged exposure to loud noises causes neuronal hyperexcitability and increases the risk of tinnitus. This study reveals that this type of tinnitus is mediated by noise-induced neuroinflammation; blockade of neuroinflammatory responses prevents noise-induced neuronal excitation/inhibition imbalance and tinnitus.
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Affiliation(s)
- Weihua Wang
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Li. S. Zhang
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Alexander K. Zinsmaier
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Genevieve Patterson
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Emily Jean Leptich
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Savannah L. Shoemaker
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Tatiana A. Yatskievych
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Robert Gibboni
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Edward Pace
- Department of Otolaryngology, Wayne State University, Detroit, Michigan, United States of America
| | - Hao Luo
- Department of Otolaryngology, Wayne State University, Detroit, Michigan, United States of America
| | - Jinsheng Zhang
- Department of Otolaryngology, Wayne State University, Detroit, Michigan, United States of America
- Department of Communication Sciences and Disorders, Wayne State University, Detroit, Michigan, United States of America
| | - Sungchil Yang
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
- Department of Biomedical Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Shaowen Bao
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
- * E-mail:
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19
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Lima-Silveira L, Accorsi-Mendonça D, Bonagamba LGH, Almado CEL, da Silva MP, Nedoboy PE, Pilowsky PM, Machado BH. Enhancement of excitatory transmission in NTS neurons projecting to ventral medulla of rats exposed to sustained hypoxia is blunted by minocycline. J Physiol 2019; 597:2903-2923. [PMID: 30993693 DOI: 10.1113/jp277532] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/16/2019] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Rats subjected to sustained hypoxia (SH) present increases in arterial pressure (AP) and in glutamatergic transmission in the nucleus tractus solitarius (NTS) neurons sending projections to ventrolateral medulla (VLM). Treatment with minocycline, a microglial inhibitor, attenuated the increase in AP in response to SH. The increase in the amplitude of glutamatergic postsynaptic currents in the NTS-VLM neurons, induced by postsynaptic mechanisms, was blunted by minocycline treatment. The number of microglial cells was increased in the NTS of vehicle-treated SH rats but not in the NTS of minocycline-treated rats. The data show that microglial recruitment/proliferation induced by SH is associated with the enhancement of excitatory neurotransmission in NTS-VLM neurons, which may contribute to the observed increase in AP. ABSTRACT Short-term sustained hypoxia (SH) produces significant autonomic and respiratory adjustments and triggers activation of microglia, the resident immune cells in the brain. SH also enhances glutamatergic neurotransmission in the NTS. Here we evaluated the role of microglial activation induced by SH on the cardiovascular changes and mainly on glutamatergic neurotransmission in NTS neurons sending projections to the ventrolateral medulla (NTS-VLM), using a microglia inhibitor (minocycline). Direct measurement of arterial pressure (AP) in freely moving rats showed that SH (24 h, fraction of inspired oxygen ( F I , O 2 ) 0.1) in vehicle and minocycline (30 mg/kg i.p. for 3 days)-treated groups produced a significant increase in AP in relation to control groups under normoxic conditions, but this increase was significantly lower in minocycline-treated rats. Whole-cell patch-clamp recordings revealed that the active properties of the membrane were comparable among the groups. Nevertheless, the amplitudes of glutamatergic postsynaptic currents, evoked by tractus solitarius stimulation, were increased in NTS-VLM neurons of SH rats. Changes in asynchronous glutamatergic currents indicated that the observed increase in amplitude was due to postsynaptic mechanisms. These changes were blunted in the SH group previously treated with minocycline. Using immunofluorescence, we found that the number of microglial cells was increased in the NTS of vehicle-treated SH rats but not in the NTS neurons of minocycline-treated rats. Our data support the concept that microglial activation induced by SH is associated with the enhancement of excitatory neurotransmission in NTS-VLM neurons, which may contribute to the increase in AP observed in this experimental model.
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Affiliation(s)
- Ludmila Lima-Silveira
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Daniela Accorsi-Mendonça
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Leni G H Bonagamba
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Carlos Eduardo L Almado
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Melina P da Silva
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Polina E Nedoboy
- The Heart Research Institute, Sydney, New South Wales, 2042, Australia
| | - Paul M Pilowsky
- The Heart Research Institute, Sydney, New South Wales, 2042, Australia
| | - Benedito H Machado
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
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20
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MR Imaging for Assessing Injury Severity and Prognosis in Acute Traumatic Spinal Cord Injury. Radiol Clin North Am 2019; 57:319-339. [DOI: 10.1016/j.rcl.2018.09.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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21
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Martin KK, Parvin S, Garraway SM. Peripheral Inflammation Accelerates the Onset of Mechanical Hypersensitivity after Spinal Cord Injury and Engages Tumor Necrosis Factor α Signaling Mechanisms. J Neurotrauma 2019; 36:2000-2010. [PMID: 30520675 DOI: 10.1089/neu.2018.5953] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Previously, we showed that noxious stimulation of the tail produces numerous detrimental effects after spinal cord injury (SCI), including an earlier onset and increased magnitude of mechanical hypersensitivity. Expanding on these observations, this study sought to determine whether localized peripheral inflammation similarly impacts the expression of mechanical hypersensitivity after SCI. Adult rats received a moderate contusion injury at the thoracic level (Tl0) or sham surgery, and were administered complete Freund's adjuvant (CFA) or vehicle in one hindpaw 24 hours later. Examination of locomotor recovery (Basso, Beattie, and Bresnahan [BBB] score) showed no adverse effect of CFA. Mechanical testing with von Frey hairs was done at time-points ranging from 1 h to 28 days after CFA or vehicle treatment, and rats were sacrificed at 1, 7, or 28 days for cellular assessment. Unlike vehicle-treated SCI rats where mechanical hypersensitivity emerged at 14 days, CFA-treated SCI rats showed mechanical hypersensitivity as early as 1 h after CFA administration, which lasted at least 28 days. CFA-treated sham subjects also showed an early onset of mechanical hypersensitivity, but this was maintained up to 7 days after treatment. Cellular assessments revealed congruent findings. Expression levels of c-fos, tumor necrosis factor α (TNFα), TNF receptors, and members of the TNFα signaling pathway such as caspase 8 and phosphorylated extracellular related kinase (pERK) were preferentially upregulated in the lumbar spinal cord of SCI-CFA rats. Meanwhile, c-jun was significantly increased in both CFA-treated groups. Overall, these results together with our previous reports, suggest that peripheral noxious input after SCI facilitates the development of pain by mechanisms that may require TNFα signaling.
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Affiliation(s)
- Karmarcha K Martin
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Shangrila Parvin
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Sandra M Garraway
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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22
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Jeanneret V, Ospina JP, Diaz A, Manrique LG, Merino P, Gutierrez L, Torre E, Wu F, Cheng L, Yepes M. Tissue-type plasminogen activator protects the postsynaptic density in the ischemic brain. J Cereb Blood Flow Metab 2018; 38:1896-1910. [PMID: 29547062 PMCID: PMC6259311 DOI: 10.1177/0271678x18764495] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cerebral ischemia causes the presynaptic release of tissue-type plasminogen activator (tPA). The postsynaptic density (PSD) is a postsynaptic structure that provides a matrix where signaling transduction of excitatory synapses takes place. The postsynaptic density protein-95 (PSD-95) is the most abundant scaffolding protein in the postsynaptic density (PSD), where it modulates the postsynaptic response to the presynaptic release of glutamate by regulating the anchoring of glutamate receptors to the PSD. We found that tPA induces the local translation of PSD-95 mRNA and the subsequent recruitment of PSD-95 protein to the PSD, via plasminogen-independent activation of TrkB receptors. Our data show that PSD-95 is removed from the PSD during the early stages of cerebral ischemia, and that this effect is abrogated by either the release of neuronal tPA, or intravenous administration of recombinant tPA (rtPA). We report that the effect of tPA on PSD-95 is associated with inhibition of the phosphorylation and recruitment of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors to the PSD, known to amplify the effect of the excitotoxic injury, and that this is followed by TrkB-mediated protection of dendritic spines from the harmful effects of the hypoxic insult. These data reveal that tPA is a synaptic protector in the ischemic brain.
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Affiliation(s)
- Valerie Jeanneret
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA
| | - Juan P Ospina
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA
| | - Ariel Diaz
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Luis G Manrique
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Paola Merino
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Laura Gutierrez
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA
| | - Enrique Torre
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Fang Wu
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Lihong Cheng
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Manuel Yepes
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA.,3 Department of Neurology, Veterans Affairs Medical Center, Atlanta, GA, USA
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23
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The Effects of a Combination of Ion Channel Inhibitors in Female Rats Following Repeated Mild Traumatic Brain Injury. Int J Mol Sci 2018; 19:ijms19113408. [PMID: 30384417 PMCID: PMC6274967 DOI: 10.3390/ijms19113408] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/26/2018] [Accepted: 10/27/2018] [Indexed: 01/26/2023] Open
Abstract
Following mild traumatic brain injury (mTBI), the ionic homeostasis of the central nervous system (CNS) becomes imbalanced. Excess Ca2+ influx into cells triggers molecular cascades, which result in detrimental effects. The authors assessed the effects of a combination of ion channel inhibitors (ICI) following repeated mTBI (rmTBI). Adult female rats were subjected to two rmTBI weight-drop injuries 24 h apart, sham procedures (sham), or no procedures (normal). Lomerizine, which inhibits voltage-gated calcium channels, was administered orally twice daily, whereas YM872 and Brilliant Blue G, inhibiting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and P2X₇ receptors, respectively, were delivered intraperitoneally every 48 h post-injury. Vehicle treatment controls were included for rmTBI, sham, and normal groups. At 11 days following rmTBI, there was a significant increase in the time taken to cross the 3 cm beam, as a sub-analysis of neurological severity score (NSS) assessments, compared with the normal control (p < 0.05), and a significant decrease in learning-associated improvement in rmTBI in Morris water maze (MWM) trials relative to the sham (p < 0.05). ICI-treated rmTBI animals were not different to sham, normal controls, or rmTBI treated with vehicle in all neurological severity score and Morris water maze assessments (p > 0.05). rmTBI resulted in increases in microglial cell density, antioxidant responses (manganese-dependent superoxide dismutase (MnSOD) immunoreactivity), and alterations to node of Ranvier structure. ICI treatment decreased microglial density, MnSOD immunoreactivity, and abnormalities of the node of Ranvier compared with vehicle controls (p < 0.01). The authors' findings demonstrate the beneficial effects of the combinatorial ICI treatment on day 11 post-rmTBI, suggesting an attractive therapeutic strategy against the damage induced by excess Ca2+ following rmTBI.
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24
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Wang W, Zinsmaier AK, Firestone E, Lin R, Yatskievych TA, Yang S, Zhang J, Bao S. Blocking Tumor Necrosis Factor-Alpha Expression Prevents Blast-Induced Excitatory/Inhibitory Synaptic Imbalance and Parvalbumin-Positive Interneuron Loss in the Hippocampus. J Neurotrauma 2018; 35:2306-2316. [PMID: 29649942 DOI: 10.1089/neu.2018.5688] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) is a major cause of neurological disorder and death in civilian and military populations. It comprises two components-direct injury from the traumatic impact and secondary injury from ensuing neural inflammatory responses. Blocking tumor necrosis factor-alpha (TNF-α), a central regulator of neural inflammation, has been shown to improve functional recovery after TBI. However, the mechanisms underlying those therapeutic effects are still poorly understood. Here, we examined effects of 3,6'-dithiothalidomide (dTT), a potentially therapeutic TNF-α inhibitor, in mice with blast-induced TBI. We found that blast exposure resulted in elevated expression of TNF-α, activation of microglial cells, enhanced excitatory synaptic transmission, reduced inhibitory synaptic transmission, and a loss of parvalbumin-positive (PV+) inhibitory interneurons. Administration of dTT for 5 days after the blast exposure completely suppressed blast-induced increases in TNF-α transcription, largely reversed blasted-induced synaptic changes, and prevented PV+ neuron loss. However, blocking TNF-α expression by dTT failed to mitigate blast-induced microglial activation in the hippocampus, as evidenced by their non-ramified morphology. These results indicate that TNF-α plays a major role in modulating neuronal functions in blast-induced TBI and that it is a potential target for treatment of TBI-related brain disorders.
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Affiliation(s)
- Weihua Wang
- 1 Department of Physiology, College of Medicine, University of Arizona , Tucson, Arizona
| | - Alexander K Zinsmaier
- 1 Department of Physiology, College of Medicine, University of Arizona , Tucson, Arizona
| | - Ethan Firestone
- 2 Department of Otolaryngology-Head and Neck Surgery and Department of Communication Sciences and Disorders, School of Medicine, Wayne State University , Detroit, Michigan
| | - Ruizhu Lin
- 1 Department of Physiology, College of Medicine, University of Arizona , Tucson, Arizona.,3 Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University , Guangzhou, China
| | - Tatiana A Yatskievych
- 1 Department of Physiology, College of Medicine, University of Arizona , Tucson, Arizona
| | - Sungchil Yang
- 4 Department of Biomedical Sciences, City University of Hong Kong , Kowloon, Hong Kong, China
| | - Jinsheng Zhang
- 2 Department of Otolaryngology-Head and Neck Surgery and Department of Communication Sciences and Disorders, School of Medicine, Wayne State University , Detroit, Michigan
| | - Shaowen Bao
- 1 Department of Physiology, College of Medicine, University of Arizona , Tucson, Arizona
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25
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Neuronal death/apoptosis induced by intracellular zinc deficiency associated with changes in amino-acid neurotransmitters and glutamate receptor subtypes. J Inorg Biochem 2017; 179:54-59. [PMID: 29175628 DOI: 10.1016/j.jinorgbio.2017.11.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/07/2017] [Accepted: 11/17/2017] [Indexed: 12/13/2022]
Abstract
In the present study, a model of zinc deficiency was developed by exposing primary neurons to an N,N,N',N'-Tetrakis (2-pyridylmethyl) ethylenediamine (TPEN)-containing medium. The cell survival rate, apoptosis rate, intracellular and extracellular concentrations of 4 amino acids, and the expression of 2 glutamate receptor subtypes α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (GluR2)and N-methyl-d-aspartate receptor subtype 2B (NR2B) were evaluated in zinc-deficient cells. The results revealed that zinc deficiency led to a decrease in cell viability and an increase in the apoptosis rate. Additionally, in cultured neurons, zinc deficiency led to an increase in the concentration of aspartic acid (Asp) and a decrease in the concentrations of glutamate (Glu), glycine (Gly), and gamma-aminobutyric acid (GABA). These changes were reversed by concurrent zinc supplementation. Furthermore, zinc deficiency led to an increase in the secreted amounts of Glu, Gly, and Asp but a decrease in secreted amounts of GABA, as measured using the concentrations of these amino acids in the cell-culture medium. These changes were partially reversed by zinc supplementation. Finally, zinc deficiency led to a significant decrease in GluR2 expression and an increase in NR2B expression in cultured neurons, whereas simultaneous treatment with zinc sulfate (ZnSO4) prevented these changes. These results suggest that zinc deficiency-induced neuronal death/apoptosis involves changes in the concentrations of 4 amino acid neurotransmitters and the expression of 2 glutamate receptor subtypes.
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Effect of Progesterone on Cerebral Vasospasm and Neurobehavioral Outcomes in a Rodent Model of Subarachnoid Hemorrhage. World Neurosurg 2017; 110:e150-e159. [PMID: 29097330 DOI: 10.1016/j.wneu.2017.10.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 10/19/2017] [Accepted: 10/21/2017] [Indexed: 11/20/2022]
Abstract
BACKGROUND Subarachnoid hemorrhage (SAH) induces widespread inflammation leading to cellular injury, vasospasm, and ischemia. Evidence suggests that progesterone (PROG) can improve functional recovery in acute brain injury owing to its anti-inflammatory and neuroprotective properties, which could also be beneficial in SAH. We hypothesized that PROG treatment attenuates inflammation-mediated cerebral vasospasm and microglial activation, improves synaptic connectivity, and ameliorates functional recovery after SAH. METHODS We investigated the effect of PROG in a cisternal SAH model in adult male C57BL/6 mice. Neurobehavioral outcomes were evaluated using rotarod latency and grip strength tests. Basilar artery perimeter, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptor 1 (GluR1)/synaptophysin colocalization, and Iba-1 immunoreactivity were quantified histologically. RESULTS PROG (8 mg/kg) significantly improved rotarod latency at day 6 and grip strength at day 9. PROG-treated mice had significantly reduced basilar artery vasospasm at 24 hours. GluR1/synaptophysin colocalization, indicative of synaptic GluR1, was significantly reduced in the SAH+Vehicle group at 24 hours, and PROG treatment significantly attenuated this reduction. PROG treatment significantly reduced microglial cell activation and proliferation in cerebellum and cortex but not in the brainstem at 10 days. CONCLUSIONS PROG treatment ameliorated cerebral vasospasm, reduced microglial activation, restored synaptic GluR1 localization, and improved neurobehavioral performance in a murine model of SAH. These results provide a rationale for further translational testing of PROG therapy in SAH.
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Hippocampal TNFα Signaling Contributes to Seizure Generation in an Infection-Induced Mouse Model of Limbic Epilepsy. eNeuro 2017; 4:eN-NWR-0105-17. [PMID: 28497109 PMCID: PMC5422919 DOI: 10.1523/eneuro.0105-17.2017] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 01/02/2023] Open
Abstract
Central nervous system infection can induce epilepsy that is often refractory to established antiseizure drugs. Previous studies in the Theiler's murine encephalomyelitis virus (TMEV)-induced mouse model of limbic epilepsy have demonstrated the importance of inflammation, especially that mediated by tumor necrosis factor-α (TNFα), in the development of acute seizures. TNFα modulates glutamate receptor trafficking via TNF receptor 1 (TNFR1) to cause increased excitatory synaptic transmission. Therefore, we hypothesized that an increase in TNFα signaling after TMEV infection might contribute to acute seizures. We found a significant increase in both mRNA and protein levels of TNFα and the protein expression ratio of TNF receptors (TNFR1:TNFR2) in the hippocampus, a brain region most likely involved in seizure initiation, after TMEV infection, which suggests that TNFα signaling, predominantly through TNFR1, may contribute to limbic hyperexcitability. An increase in hippocampal cell-surface glutamate receptor expression was also observed during acute seizures. Although pharmacological inhibition of TNFR1-mediated signaling had no effect on acute seizures, several lines of genetically modified animals deficient in either TNFα or TNFRs had robust changes in seizure incidence and severity after TMEV infection. TNFR2-/- mice were highly susceptible to developing acute seizures, suggesting that TNFR2-mediated signaling may provide beneficial effects during the acute seizure period. Taken together, the present results suggest that inflammation in the hippocampus, caused predominantly by TNFα signaling, contributes to hyperexcitability and acute seizures after TMEV infection. Pharmacotherapies designed to suppress TNFR1-mediated or augment TNFR2-mediated effects of TNFα may provide antiseizure and disease-modifying effects after central nervous system infection.
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Blaylock RL. Parkinson's disease: Microglial/macrophage-induced immunoexcitotoxicity as a central mechanism of neurodegeneration. Surg Neurol Int 2017; 8:65. [PMID: 28540131 PMCID: PMC5421223 DOI: 10.4103/sni.sni_441_16] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/01/2017] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease is one of the several neurodegenerative disorders that affects aging individuals, with approximately 1% of those over the age of 60 years developing the disorder in their lifetime. The disease has the characteristics of a progressive disorder in most people, with a common pattern of pathological change occurring in the nervous system that extends beyond the classical striatal degeneration of dopaminergic neurons. Earlier studies concluded that the disease was a disorder of alpha-synuclein, with the formation of aggregates of abnormal alpha-synuclein being characteristic. More recent studies have concluded that inflammation plays a central role in the disorder and that the characteristic findings can be accounted for by either mutation or oxidative damage to alpha-synuclein, with resulting immune reactions from surrounding microglia, astrocytes, and macrophages. What has been all but ignored in most of these studies is the role played by excitotoxicity and that the two processes are intimately linked, with inflammation triggered cell signaling enhancing the excitotoxic cascade. Further, there is growing evidence that it is the excitotoxic reactions that actually cause the neurodegeneration. I have coined the name immunoexcitotoxicity to describe this link between inflammation and excitotoxicity. It appears that the two processes are rarely, if ever, separated in neurodegenerative diseases.
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A meta-analysis of the effect of different neuroprotective drugs in management of patients with traumatic brain injury. Neurosurg Rev 2016; 41:427-438. [PMID: 27539610 DOI: 10.1007/s10143-016-0775-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/07/2016] [Accepted: 08/04/2016] [Indexed: 01/08/2023]
Abstract
Traumatic brain injury is a major problem worldwide. Our objective is to synthesize available evidence in the literature concerning the effectiveness of neuroprotective drugs (cerebrolysin, citicoline, and piracetam) on Glasgow outcome score (GOS), cognitive performance, and survival in traumatic brain injury patients. Comprehensive search of electronic databases, search engines, and conferences proceedings; hand search journals; searching reference lists of relevant articles, theses, and local publications; and contact of authors for incomplete data were performed. Studies included patients in all age groups regardless of severity of trauma. There was no publication date restriction. Two reviewers independently extracted data from each study. Fixed effect or random effects model selection depends on results of statistical tests for heterogeneity. The literature search yielded 13 studies. Patients treated with cerebrolysin (n = 112) had favorable GOS three times more than controls (OR 3.019; 95 % CI 1.76 to 5.16; p = 0.003*). The odds of cognition improvement in the treatment group was 3.4 times more than controls (OR 3.4; 95 % CI 1.82 to 5.21; p < 0.001*). Survival of cerebrolysin-treated patients did not differ from controls (103 patients; OR = 2.81; 95 % CI 0.905 to 8.76). Citicoline did not improve GOS (1355 patients; OR 0.96; 95 % CI 0.830 to 1.129; p = 0.676), cognitive performance (4 studies; 1291 patients; OR 1.35; 95 % CI 0.58 to 3.16; p = 0.478), and survival (1037 patients; OR = 1.38; 95 % CI 0.855 to 2.239). One study showed a positive effect of piracetam on cognition. Further research with high validity is needed to reach a solid conclusion about the use of neuroprotective drugs in cases of brain injury.
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Braegelmann KM, Streeter KA, Fields DP, Baker TL. Plasticity in respiratory motor neurons in response to reduced synaptic inputs: A form of homeostatic plasticity in respiratory control? Exp Neurol 2016; 287:225-234. [PMID: 27456270 DOI: 10.1016/j.expneurol.2016.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 06/16/2016] [Accepted: 07/20/2016] [Indexed: 12/31/2022]
Abstract
For most individuals, the respiratory control system produces a remarkably stable and coordinated motor output-recognizable as a breath-from birth until death. Very little is understood regarding the processes by which the respiratory control system maintains network stability in the presence of changing physiological demands and network properties that occur throughout life. An emerging principle of neuroscience is that neural activity is sensed and adjusted locally to assure that neurons continue to operate in an optimal range, yet to date, it is unknown whether such homeostatic plasticity is a feature of the neurons controlling breathing. Here, we review the evidence that local mechanisms sense and respond to perturbations in respiratory neural activity, with a focus on plasticity in respiratory motor neurons. We discuss whether these forms of plasticity represent homeostatic plasticity in respiratory control. We present new analyses demonstrating that reductions in synaptic inputs to phrenic motor neurons elicit a compensatory enhancement of phrenic inspiratory motor output, a form of plasticity termed inactivity-induced phrenic motor facilitation (iPMF), that is proportional to the magnitude of activity deprivation. Although the physiological role of iPMF is not understood, we hypothesize that it has an important role in protecting the drive to breathe during conditions of prolonged or intermittent reductions in respiratory neural activity, such as following spinal cord injury or during central sleep apnea.
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Affiliation(s)
- K M Braegelmann
- Department of Comparative Biosciences, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, United States
| | - K A Streeter
- Department of Comparative Biosciences, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, United States
| | - D P Fields
- Department of Comparative Biosciences, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, United States
| | - T L Baker
- Department of Comparative Biosciences, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, United States.
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Lee S, Mattingly A, Lin A, Sacramento J, Mannent L, Castel MN, Canolle B, Delbary-Gossart S, Ferzaz B, Morganti JM, Rosi S, Ferguson AR, Manley GT, Bresnahan JC, Beattie MS. A novel antagonist of p75NTR reduces peripheral expansion and CNS trafficking of pro-inflammatory monocytes and spares function after traumatic brain injury. J Neuroinflammation 2016; 13:88. [PMID: 27102880 PMCID: PMC4840857 DOI: 10.1186/s12974-016-0544-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/10/2016] [Indexed: 12/17/2022] Open
Abstract
Background Traumatic brain injury (TBI) results in long-term neurological deficits, which may be mediated in part by pro-inflammatory responses in both the injured brain and the circulation. Inflammation may be involved in the subsequent development of neurodegenerative diseases and post-injury seizures. The p75 neurotrophin receptor (p75NTR) has multiple biological functions, affecting cell survival, apoptotic cell death, axonal growth, and degeneration in pathological conditions. We recently found that EVT901, a novel piperazine derivative that inhibits p75NTR oligomerization, is neuroprotective, reduces microglial activation, and improves outcomes in two models of TBI in rats. Since TBI elicits both CNS and peripheral inflammation, we used a mouse model of TBI to examine whether EVT901 would affect peripheral immune responses and trafficking to the injured brain. Methods Cortical contusion injury (CCI)-TBI of the sensory/motor cortex was induced in C57Bl/6 wild-type mice and CCR2+/RFP heterozygote transgenic mice, followed by treatment with EVT901, a selective antagonist of p75NTR, or vehicle by i.p. injection at 4 h after injury and then daily for 7 days. Brain and blood were collected at 1 and 6 weeks after injury. Flow cytometry and histological analysis were used to determine peripheral immune responses and trafficking of peripheral immune cells into the lesion site at 1 and 6 weeks after TBI. A battery of behavioral tests administered over 6 weeks was used to evaluate neurological outcome, and stereological estimation of brain tissue volume at 6 weeks was used to assess tissue damage. Finally, multivariate principal components analysis (PCA) was used to evaluate the relationships between inflammatory events, EVT901 treatment, and neurological outcomes. Results EVT901 is neuroprotective in mouse CCI-TBI and dramatically reduced the early trafficking of CCR2+ and pro-inflammatory monocytes into the lesion site. EVT901 reduced the number of CD45highCD11b+ and CD45highF4/80+ cells in the injured brain at 6 weeks. TBI produced a significant increase in peripheral pro-inflammatory monocytes (Ly6Cint-high pro-inflammatory monocytes), and this peripheral effect was also blocked by EVT901 treatment. Further, we found that blocking p75NTR with EVT901 reduces the expansion of pro-inflammatory monocytes, and their response to LPS in vitro, supporting the idea that there is a peripheral EVT901 effect that blunts inflammation. Further, 1 week of EVT901 blocks the expansion of pro-inflammatory monocytes in the circulation after TBI, reduces the number of multiple subsets of pro-inflammatory monocytes that enter the injury site at 1 and 6 weeks post-injury, and is neuroprotective, as it was in the rat. Conclusions Together, these findings suggest that p75NTR signaling participates in the production of the peripheral pro-inflammatory response to CNS injury and implicates p75NTR as a part of the pro-inflammatory cascade. Thus, the neuroprotective effects of p75NTR antagonists might be due to a combination of central and peripheral effects, and p75NTR may play a role in the production of peripheral inflammation in addition to its many other biological roles. Thus, p75NTR may be a therapeutic target in human TBI. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0544-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sangmi Lee
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA
| | - Aaron Mattingly
- Biomedical Science Graduate Program, University of California at San Francisco, San Francisco, CA, 94143-0899, USA
| | - Amity Lin
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA
| | - Jeffrey Sacramento
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA
| | - Leda Mannent
- Early to Candidate, Sanofi Research, 195 route d'Espagne, Chilly-Mazarin, France
| | - Marie-Noelle Castel
- Early to Candidate, Sanofi Research, 195 route d'Espagne, Chilly-Mazarin, France
| | - Benoit Canolle
- Early to Candidate, Sanofi Research, 195 route d'Espagne, Chilly-Mazarin, France
| | | | - Badia Ferzaz
- Early to Candidate, Sanofi Research, 195 route d'Espagne, Chilly-Mazarin, France
| | - Josh M Morganti
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA
| | - Susanna Rosi
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA.,Biomedical Science Graduate Program, University of California at San Francisco, San Francisco, CA, 94143-0899, USA
| | - Adam R Ferguson
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA.,Biomedical Science Graduate Program, University of California at San Francisco, San Francisco, CA, 94143-0899, USA
| | - Geoffrey T Manley
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA
| | - Jacqueline C Bresnahan
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA
| | - Michael S Beattie
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California at San Francisco, Box 0899, 1001 Potrero Ave, Bldg 1, Rm 101, San Francisco, CA, 94143-0899, USA. .,Biomedical Science Graduate Program, University of California at San Francisco, San Francisco, CA, 94143-0899, USA.
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Uzunova G, Pallanti S, Hollander E. Excitatory/inhibitory imbalance in autism spectrum disorders: Implications for interventions and therapeutics. World J Biol Psychiatry 2016; 17:174-86. [PMID: 26469219 DOI: 10.3109/15622975.2015.1085597] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Imbalance between excitation and inhibition and increased excitatory-inhibitory (E-I) ratio is a common mechanism in autism spectrum disorders (ASD) that is responsible for the learning and memory, cognitive, sensory, motor deficits, and seizures occurring in these disorders. ASD are very heterogeneous and better understanding of E-I imbalance in brain will lead to better diagnosis and treatments. METHODS We perform a critical literature review of the causes and presentations of E-I imbalance in ASD. RESULTS E-I imbalance in ASD is due primarily to abnormal glutamatergic and GABAergic neurotransmission in key brain regions such as neocortex, hippocampus, amygdala, and cerebellum. Other causes are due to dysfunction of neuropeptides (oxytocin), synaptic proteins (neuroligins), and immune system molecules (cytokines). At the neuropathological level E-I imbalance in ASD is presented as a "minicolumnopathy". E-I imbalance alters the manner by which the brain processes information and regulates behaviour. New developments for investigating E-I imbalance such as optogenetics and transcranial magnetic stimulation (TMS) are presented. Non-invasive brain stimulation methods such as TMS for treatment of the core symptoms of ASD are discussed. CONCLUSIONS Understanding E-I imbalance has important implications for developing better pharmacological and behavioural treatments for ASD, including TMS, new drugs, biomarkers and patient stratification.
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Affiliation(s)
- Genoveva Uzunova
- a Albert Einstein College of Medicine and Montefiore Medical Center , Bronx , NY , USA
| | - Stefano Pallanti
- a Albert Einstein College of Medicine and Montefiore Medical Center , Bronx , NY , USA.,b Psychiatry and Behavioural Sciences, UC Davis Health System , CA , USA.,c Department Psychiatry , University of Florence , Florence , Italy.,d Icahn School of Medicine at Mount Sinai , New York , NY , USA
| | - Eric Hollander
- a Albert Einstein College of Medicine and Montefiore Medical Center , Bronx , NY , USA
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Klein RC, Acheson SK, Qadri LH, Dawson AA, Rodriguiz RM, Wetsel WC, Moore SD, Laskowitz DT, Dawson HN. Opposing effects of traumatic brain injury on excitatory synaptic function in the lateral amygdala in the absence and presence of preinjury stress. J Neurosci Res 2015; 94:579-89. [DOI: 10.1002/jnr.23702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/23/2015] [Accepted: 11/25/2015] [Indexed: 01/18/2023]
Affiliation(s)
- Rebecca C. Klein
- Department of Psychiatry and Behavioral Sciences; Duke University Medical Center; Durham North Carolina
- VISN 6 MIRECC, Durham Veterans Affairs Medical Center; Durham North Carolina
| | - Shawn K. Acheson
- Department of Psychiatry and Behavioral Sciences; Duke University Medical Center; Durham North Carolina
- Neurobiology Research Laboratory, Durham Veterans Affairs Medical Center; Durham North Carolina
| | - Laura H. Qadri
- Department of Psychiatry and Behavioral Sciences; Duke University Medical Center; Durham North Carolina
| | - Alina A. Dawson
- Department of Neurology; Duke University Medical Center; Durham North Carolina
| | - Ramona M. Rodriguiz
- Department of Psychiatry and Behavioral Sciences; Duke University Medical Center; Durham North Carolina
- Mouse Behavioral and Neuroendocrine Analysis Core Facility; Duke University Medical Center; Durham North Carolina
| | - William C. Wetsel
- Department of Psychiatry and Behavioral Sciences; Duke University Medical Center; Durham North Carolina
- Mouse Behavioral and Neuroendocrine Analysis Core Facility; Duke University Medical Center; Durham North Carolina
- Departments of Neurobiology and Cell Biology; Duke University Medical Center; Durham North Carolina
| | - Scott D. Moore
- Department of Psychiatry and Behavioral Sciences; Duke University Medical Center; Durham North Carolina
- VISN 6 MIRECC, Durham Veterans Affairs Medical Center; Durham North Carolina
| | - Daniel T. Laskowitz
- Department of Neurology; Duke University Medical Center; Durham North Carolina
| | - Hana N. Dawson
- Department of Neurology; Duke University Medical Center; Durham North Carolina
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Xavier AL, Menezes JRL, Goldman SA, Nedergaard M. Fine-tuning the central nervous system: microglial modelling of cells and synapses. Philos Trans R Soc Lond B Biol Sci 2015; 369:20130593. [PMID: 25225087 DOI: 10.1098/rstb.2013.0593] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Microglia constitute as much as 10-15% of all cells in the mammalian central nervous system (CNS) and are the only glial cells that do not arise from the neuroectoderm. As the principal CNS immune cells, microglial cells represent the first line of defence in response to exogenous threats. Past studies have largely been dedicated to defining the complex immune functions of microglial cells. However, our understanding of the roles of microglia has expanded radically over the past years. It is now clear that microglia are critically involved in shaping neural circuits in both the developing and adult CNS, and in modulating synaptic transmission in the adult brain. Intriguingly, microglial cells appear to use the same sets of tools, including cytokine and chemokine release as well as phagocytosis, whether modulating neural function or mediating the brain's innate immune responses. This review will discuss recent developments that have broadened our views of neuro-glial signalling to include the contribution of microglial cells.
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Affiliation(s)
- Anna L Xavier
- Laboratório de Neuroanatomia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-902, Brazil Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY 14642, USA
| | - João R L Menezes
- Laboratório de Neuroanatomia Celular, Instituto de Ciências Biomédicas, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Steven A Goldman
- Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY 14642, USA
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Wang S, Zhang J, Sheng T, Lu W, Miao D. Hippocampal ischemia causes deficits in local field potential and synaptic plasticity. J Biomed Res 2015; 29:370-9. [PMID: 26445570 PMCID: PMC4585431 DOI: 10.7555/jbr.29.20150010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/16/2015] [Accepted: 05/10/2015] [Indexed: 11/16/2022] Open
Abstract
The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-1-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory postsynaptic potentials (fEPSPs) on CA1 hippocampal neurons in peri-infarct regions of the endothelin-1-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dampened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synaptic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.
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Affiliation(s)
- Shaoli Wang
- The Research Center for Bone and Stem Cells, Department of Human Anatomy
| | - Jingyun Zhang
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University , Nanjing, Jiangsu 210096 , China
| | - Tao Sheng
- The Center of Metabolic Disease Research, Nanjing Medical University , Nanjing, Jiangsu 210029 , China
| | - Wei Lu
- Department of Neurobiology ; The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University , Nanjing, Jiangsu 210096 , China
| | - Dengshun Miao
- The Research Center for Bone and Stem Cells, Department of Human Anatomy
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Cheng N, Hu X, Tian T, Lu W. PKMζ knockdown disrupts post-ischemic long-term potentiation via inhibiting postsynaptic expression of aminomethyl phosphonic acid receptors. J Biomed Res 2015; 29:241-9. [PMID: 26060448 PMCID: PMC4449492 DOI: 10.7555/jbr.28.20140033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 03/11/2014] [Accepted: 05/07/2014] [Indexed: 11/12/2022] Open
Abstract
Post-ischemic long-term potentiation (i-LTP) is a pathological form of plasticity that was observed in glutamate receptor-mediated neurotransmission after stroke and may exert a detrimental effect via facilitating excitotoxic damage. The mechanism underlying i-LTP, however, remains less understood. By employing electrophysiological recording and immunofluorescence assay on hippocampal slices and cultured neurons, we found that protein kinase Mζ (PKMζ), an atypical protein kinase C isoform, was involved in enhancing aminomethyl phosphonic acid (AMPA) receptor (AMPAR) expression after i-LTP induction. PKMζ knockdown attenuated postsynaptic expression of AMPA receptors and disrupted i-LTP. Consistently, we observed less neuronal death of cultured hippocampal cells with PKMζ knockdown. Meanwhile, these findings indicate that PKMζ plays an important role in i-LTP by regulating postsynaptic expression of AMPA receptors. This work adds new knowledge to the mechanism of i-LTP, and thus is helpful to find the potential target for clinical therapy of ischemic stroke.
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Affiliation(s)
- Nan Cheng
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xiaoqiao Hu
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Tian Tian
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Wei Lu
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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Involvement of GluR2 up-regulation in neuroprotection by electroacupuncture pretreatment via cannabinoid CB1 receptor in mice. Sci Rep 2015; 5:9490. [PMID: 25830356 PMCID: PMC4381620 DOI: 10.1038/srep09490] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/19/2015] [Indexed: 01/05/2023] Open
Abstract
We investigated whether glutamate receptor subunit 2 (GluR2) is involved in EA pretreatment-induced neuroprotection via cannabinoid CB1 receptors (CB1R) after global cerebral ischemia in mice. Two hours after electric acupuncture (EA) pretreatment, global cerebral ischemia (GCI) was induced by bilateral common carotid artery occlusion (BCCAO) for 20 min. The GluR2 expression was examined in the hippocampus after reperfusion. Cell survival, neuronal apoptosis, the Bax/Bcl-2 ratio and neurological scores were evaluated at 24 h after BCCAO in the presence or absence of the GluR2 inhibitor. Furthermore, the GluR2 was determined in the presence and absence of CB1R inhibitor. Our results showed EA pretreatment enhanced expression of GluR2 in the hippocampus 2 h after reperfusion. Moreover, EA pretreatment improved neurological outcome, promoted cell survival, inhibited neuronal apoptosis, and decreased the Bax/Bcl-2 ratio after reperfusion. GluR2 knockdown by GluR2 siRNA effectively reversed the beneficial effects of EA pretreatment. Furthermore, CB1R siRNA and two CB1R antagonists blocked the elevation of GluR2 expression by EA pretreatment, whereas the two CB1R agonists up-regulated GluR2 expression as EA pretreatment. In conclusion, GluR2 up-regulation is involved in neuroprotection of EA pretreatment against GCI through CB1R, suggesting that GluR2 may be a novel target for stroke intervention.
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Garraway SM, Woller SA, Huie JR, Hartman JJ, Hook MA, Miranda RC, Huang YJ, Ferguson AR, Grau JW. Peripheral noxious stimulation reduces withdrawal threshold to mechanical stimuli after spinal cord injury: role of tumor necrosis factor alpha and apoptosis. Pain 2014; 155:2344-59. [PMID: 25180012 DOI: 10.1016/j.pain.2014.08.034] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 08/12/2014] [Accepted: 08/26/2014] [Indexed: 01/23/2023]
Abstract
We previously showed that peripheral noxious input after spinal cord injury (SCI) inhibits beneficial spinal plasticity and impairs recovery of locomotor and bladder functions. These observations suggest that noxious input may similarly affect the development and maintenance of chronic neuropathic pain, an important consequence of SCI. In adult rats with a moderate contusion SCI, we investigated the effect of noxious tail stimulation, administered 1 day after SCI on mechanical withdrawal responses to von Frey stimuli from 1 to 28 days after treatment. In addition, because the proinflammatory cytokine tumor necrosis factor alpha (TNFα) is implicated in numerous injury-induced processes including pain hypersensitivity, we assessed the temporal and spatial expression of TNFα, TNF receptors, and several downstream signaling targets after stimulation. Our results showed that unlike sham surgery or SCI only, nociceptive stimulation after SCI induced mechanical sensitivity by 24h. These behavioral changes were accompanied by increased expression of TNFα. Cellular assessments of downstream targets of TNFα revealed that nociceptive stimulation increased the expression of caspase 8 and the active subunit (12 kDa) of caspase 3, indicative of active apoptosis at a time point consistent with the onset of mechanical allodynia. In addition, immunohistochemical analysis revealed distinct morphological signs of apoptosis in neurons and microglia at 24h after stimulation. Interestingly, expression of the inflammatory mediator NFκB was unaltered by nociceptive stimulation. These results suggest that noxious input caudal to the level of SCI can increase the onset and expression of behavioral responses indicative of pain, potentially involving TNFα signaling.
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Affiliation(s)
- Sandra M Garraway
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA.
| | - Sarah A Woller
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - J Russell Huie
- Department of Neurological Surgery, Brain and Spinal Injury Center (BASIC), University of California, San Francisco, 1001 Potrero Ave, Bldg 1, Room 101, San Francisco, CA 94110, USA
| | - John J Hartman
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - Michelle A Hook
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - Rajesh C Miranda
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, College of Medicine, Medical Research and Education Bldg, 8447 State Highway 47, Bryan, TX 77807-3260, USA
| | - Yung-Jen Huang
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - Adam R Ferguson
- Department of Neurological Surgery, Brain and Spinal Injury Center (BASIC), University of California, San Francisco, 1001 Potrero Ave, Bldg 1, Room 101, San Francisco, CA 94110, USA
| | - James W Grau
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
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Tumor necrosis factor alpha: a link between neuroinflammation and excitotoxicity. Mediators Inflamm 2014; 2014:861231. [PMID: 24966471 PMCID: PMC4055424 DOI: 10.1155/2014/861231] [Citation(s) in RCA: 439] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 05/07/2014] [Indexed: 02/08/2023] Open
Abstract
Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine that exerts both homeostatic and pathophysiological roles in the central nervous system. In pathological conditions, microglia release large amounts of TNF-α; this de novo production of TNF-α is an important component of the so-called neuroinflammatory response that is associated with several neurological disorders. In addition, TNF-α can potentiate glutamate-mediated cytotoxicity by two complementary mechanisms: indirectly, by inhibiting glutamate transport on astrocytes, and directly, by rapidly triggering the surface expression of Ca+2 permeable-AMPA receptors and NMDA receptors, while decreasing inhibitory GABAA receptors on neurons. Thus, the net effect of TNF-α is to alter the balance of excitation and inhibition resulting in a higher synaptic excitatory/inhibitory ratio. This review summarizes the current knowledge of the cellular and molecular mechanisms by which TNF-α links the neuroinflammatory and excitotoxic processes that occur in several neurodegenerative diseases, but with a special emphasis on amyotrophic lateral sclerosis (ALS). As microglial activation and upregulation of TNF-α expression is a common feature of several CNS diseases, as well as chronic opioid exposure and neuropathic pain, modulating TNF-α signaling may represent a valuable target for intervention.
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Roet KCD, Verhaagen J. Understanding the neural repair-promoting properties of olfactory ensheathing cells. Exp Neurol 2014; 261:594-609. [PMID: 24842489 DOI: 10.1016/j.expneurol.2014.05.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 12/13/2022]
Abstract
Olfactory ensheathing glial cells (OECs) are a specialized type of glia that form a continuously aligned cellular pathway that actively supports unprecedented regeneration of primary olfactory axons from the periphery into the central nervous system. Implantation of OECs stimulates neural repair in experimental models of spinal cord, brain and peripheral nerve injury and delays disease progression in animal models for neurodegenerative diseases like amyotrophic lateral sclerosis. OECs implanted in the injured spinal cord display a plethora of pro-regenerative effects; they promote axonal regeneration, reorganize the glial scar, remyelinate axons, stimulate blood vessel formation, have phagocytic properties and modulate the immune response. Recently genome wide transcriptional profiling and proteomics analysis combined with classical or larger scale "medium-throughput" bioassays have provided novel insights into the molecular mechanism that endow OECs with their pro-regenerative properties. Here we review these studies and show that the gaps that existed in our understanding of the molecular basis of the reparative properties of OECs are narrowing. OECs express functionally connected sets of genes that can be linked to at least 10 distinct processes directly relevant to neural repair. The data indicate that OECs exhibit a range of synergistic cellular activities, including active and passive stimulation of axon regeneration (by secretion of growth factors, axon guidance molecules and basement membrane components) and critical aspects of tissue repair (by structural remodeling and support, modulation of the immune system, enhancement of neurotrophic and antigenic stimuli and by metabolizing toxic macromolecules). Future experimentation will have to further explore the newly acquired knowledge to enhance the therapeutic potential of OECs.
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Affiliation(s)
- Kasper C D Roet
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands.
| | - Joost Verhaagen
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands; Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Boelelaan 1085, Amsterdam 1081HV, The Netherlands.
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Abstract
There is increasing recognition of the involvement of the immune signaling molecule, tumor necrosis factor (TNF), in the pathophysiology of stroke and chronic brain dysfunction. TNF plays an important role both in modulating synaptic function and in the pathogenesis of neuropathic pain. Etanercept is a recombinant therapeutic that neutralizes pathologic levels of TNF. Brain imaging has demonstrated chronic intracerebral microglial activation and neuroinflammation following stroke and other forms of acute brain injury. Activated microglia release TNF, which mediates neurotoxicity in the stroke penumbra. Recent observational studies have reported rapid and sustained improvement in chronic post-stroke neurological and cognitive dysfunction following perispinal administration of etanercept. The biological plausibility of these results is supported by independent evidence demonstrating reduction in cognitive dysfunction, neuropathic pain, and microglial activation following the use of etanercept, as well as multiple studies reporting improvement in stroke outcome and cognitive impairment following therapeutic strategies designed to inhibit TNF. The causal association between etanercept treatment and reduction in post-stroke disability satisfy all of the Bradford Hill Criteria: strength of the association; consistency; specificity; temporality; biological gradient; biological plausibility; coherence; experimental evidence; and analogy. Recognition that chronic microglial activation and pathologic TNF concentration are targets that may be therapeutically addressed for years following stroke and other forms of acute brain injury provides an exciting new direction for research and treatment.
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Synaptic dysfunction in prion diseases: a trafficking problem? Int J Cell Biol 2013; 2013:543803. [PMID: 24369467 PMCID: PMC3863542 DOI: 10.1155/2013/543803] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 10/08/2013] [Indexed: 11/26/2022] Open
Abstract
Synaptic dysfunction is an important cause of neurological symptoms in prion diseases, a class of clinically heterogeneous neurodegenerative disorders caused by misfolding of the cellular prion protein (PrPC). Experimental data suggest that accumulation of misfolded PrPC in the endoplasmic reticulum (ER) may be crucial in synaptic failure, possibly because of the activation of the translational repression pathway of the unfolded protein response. Here, we report that this pathway is not operative in mouse models of genetic prion disease, consistent with our previous observation that ER stress is not involved. Building on our recent finding that ER retention of mutant PrPC impairs the secretory trafficking of calcium channels essential for synaptic function, we propose a model of pathogenicity in which intracellular retention of misfolded PrPC results in loss of function or gain of toxicity of PrPC-interacting proteins. This neurotoxic modality may also explain the phenotypic heterogeneity of prion diseases.
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Differential control of thrombospondin over synaptic glycine and AMPA receptors in spinal cord neurons. J Neurosci 2013; 33:11432-9. [PMID: 23843515 DOI: 10.1523/jneurosci.5247-12.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Thrombospondin-1 (TSP-1) is a large extracellular matrix protein secreted by astrocytes during development and inflammation. In the developing CNS, TSP-1 is involved in neuronal migration and adhesion, neurite outgrowth, and synaptogenesis. We investigated the effects of TSP-1 on neurons with mature synapses using immunocytochemistry, single-particle tracking, surface biotinylation, and calcium imaging. We show that in cultured rat spinal cord neurons TSP-1 decreased neuronal excitability by reducing the accumulation of excitatory AMPA receptors (AMPARs) and increasing that of inhibitory glycine receptors (GlyRs) in synapses. The effects of TSP-1 on GlyRs were dependent on the activation of excitatory receptors. These changes were abolished by blocking β1-integrins and mimicked by blocking β3-integrins. In the presence of TSP-1, AMPARs were less stabilized at synapses, increasing their lateral diffusion and endocytosis. Interestingly, TSP-1 counteracted the increased neuronal excitability and neuronal death induced by TNFα. These results suggest a role of TSP-1 in controlling the balance between excitation and inhibition which could help the recovery of normal synaptic activity after injury responses.
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Larsson M, Agalave N, Watanabe M, Svensson C. Distribution of transmembrane AMPA receptor regulatory protein (TARP) isoforms in the rat spinal cord. Neuroscience 2013; 248:180-93. [DOI: 10.1016/j.neuroscience.2013.05.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 05/13/2013] [Accepted: 05/31/2013] [Indexed: 02/08/2023]
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Barateiro A, Domingues HS, Fernandes A, Relvas JB, Brites D. Rat Cerebellar Slice Cultures Exposed to Bilirubin Evidence Reactive Gliosis, Excitotoxicity and Impaired Myelinogenesis that Is Prevented by AMPA and TNF-α Inhibitors. Mol Neurobiol 2013; 49:424-39. [DOI: 10.1007/s12035-013-8530-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/05/2013] [Indexed: 12/11/2022]
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Ferguson AR, Irvine KA, Gensel JC, Nielson JL, Lin A, Ly J, Segal MR, Ratan RR, Bresnahan JC, Beattie MS. Derivation of multivariate syndromic outcome metrics for consistent testing across multiple models of cervical spinal cord injury in rats. PLoS One 2013; 8:e59712. [PMID: 23544088 PMCID: PMC3609747 DOI: 10.1371/journal.pone.0059712] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/17/2013] [Indexed: 12/13/2022] Open
Abstract
Spinal cord injury (SCI) and other neurological disorders involve complex biological and functional changes. Well-characterized preclinical models provide a powerful tool for understanding mechanisms of disease; however managing information produced by experimental models represents a significant challenge for translating findings across research projects and presents a substantial hurdle for translation of novel therapies to humans. In the present work we demonstrate a novel ‘syndromic’ information-processing approach for capitalizing on heterogeneous data from diverse preclinical models of SCI to discover translational outcomes for therapeutic testing. We first built a large, detailed repository of preclinical outcome data from 10 years of basic research on cervical SCI in rats, and then applied multivariate pattern detection techniques to extract features that are conserved across different injury models. We then applied this translational knowledge to derive a data-driven multivariate metric that provides a common ‘ruler’ for comparisons of outcomes across different types of injury (NYU/MASCIS weight drop injuries, Infinite Horizons (IH) injuries, and hemisection injuries). The findings revealed that each individual endpoint provides a different view of the SCI syndrome, and that considering any single outcome measure in isolation provides a misleading, incomplete view of the SCI syndrome. This limitation was overcome by taking a novel multivariate integrative approach for leveraging complex data from preclinical models of neurological disease to identify therapies that target multiple outcomes. We suggest that applying this syndromic approach provides a roadmap for translating therapies for SCI and other complex neurological diseases.
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Affiliation(s)
- Adam R. Ferguson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (ARF); (MSB)
| | - Karen-Amanda Irvine
- Department of Comparative Medicine, Stanford University, Palo Alto, California, United States of America
| | - John C. Gensel
- Department of Physiology, Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, Kentucky, United States of America
| | - Jessica L. Nielson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Amity Lin
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Johnathan Ly
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Mark R. Segal
- Center for Bioinformatics and Molecular Biostatistics, Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, United States of America
| | - Rajiv R. Ratan
- Burke-Cornell Medical Research Institute, Department of Neurology and Neuroscience, Weill Medical College of Cornell University, White Plains, New York, United States of America
| | - Jacqueline C. Bresnahan
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Michael S. Beattie
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (ARF); (MSB)
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Álvarez XA, Figueroa J, Muresanu D. Peptidergic drugs for the treatment of traumatic brain injury. FUTURE NEUROLOGY 2013. [DOI: 10.2217/fnl.12.95] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Traumatic brain injury (TBI) is a devastating medical condition that has an enormous socioeconomic impact because it affects more than 10 million people annually worldwide and is associated with high rates of hospitalization, mortality and disability. Although TBI survival has improved continuously for decades, particularly in developing countries, implementation of an effective drug therapy for TBI represents an unmet clinical need. All confirmatory trials conducted to date with drugs targeting a single TBI pathological pathway failed to show clinical efficacy, probably because TBI pathophysiology involves multiple cellular and molecular mechanisms of secondary brain damage. According to current scientific evidence of the participation of peptide-mediated mechanisms in the processes of brain injury and repair after TBI, peptidergic drugs represent a multimodal therapy alternative to improve acute outcome and long-term recovery in TBI patients. Preliminary randomized-controlled clinical trials and open-label studies conducted to date with the peptidergic drug Cerebrolysin® (Ever Neuro Pharma GmbH, Unterach, Austria) and with the endogenous neuropeptides progesterone and erythropoietin, showed positive clinical results. Cerebrolysin-treated patients had a faster clinical recovery, a shorter hospitalization time and a better long-term outcome. Treatment with progesterone showed advantages over placebo regarding TBI mortality and clinical outcome, whereas erythropoietin only reduced mortality. Further validation of these promising findings in confirmatory randomized-controlled clinical trials is warranted. This article reviews the scientific basis and clinical evidence on the development of multimodal peptidergic drugs as a therapeutic option for the effective treatment of TBI patients.
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Affiliation(s)
| | - Jesús Figueroa
- Rehabilitation Department, Santiago University Hospital, Santiago de Compostela, Spain
| | - Dafin Muresanu
- Department of Neurology, University of Medicine & Pharmacy ‘Iuliu Hatieganu’, Cluj-Napoca, Romania
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A noncanonical postsynaptic transport route for a GPCR belonging to the serotonin receptor family. J Neurosci 2013; 32:17998-8008. [PMID: 23238716 DOI: 10.1523/jneurosci.1804-12.2012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Postsynaptic receptor trafficking plays an essential role in tuning neurotransmission and signal plasticity and has emerged as a potential therapeutic target in neuropsychiatric disease. Using a novel application of fluorescence recovery after photobleaching in rat hippocampal neurons, we examined transport from the soma to dendrites of seven G-protein-coupled receptors (GPCRs) implicated in mood disorders. Most GPCRs were delivered to dendrites via lateral diffusion, but one GPCR, the serotonin 1B receptor (5-HT(1B)), was delivered to the dendrites in secretory vesicles. Within the dendrites, 5-HT(1B) were stored in a reservoir of accessible vesicles that were recruited to preferential sites in plasma membrane, as observed with superecliptic pHluorin labeling. After membrane recruitment, 5-HT(1B) transport via lateral diffusion and temporal confinement to inhibitory and excitatory synapses was monitored by single particle tracking. These results suggest an alternative mechanism for control of neuronal activity via a GPCR that has been implicated in mood regulation.
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Poulsen MH, Lucas S, Bach TB, Barslund AF, Wenzler C, Jensen CB, Kristensen AS, Strømgaard K. Structure-activity relationship studies of argiotoxins: selective and potent inhibitors of ionotropic glutamate receptors. J Med Chem 2013; 56:1171-81. [PMID: 23320429 DOI: 10.1021/jm301602d] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Argiotoxin-636 (ArgTX-636), a natural product from the spider Argiope lobata, is a potent but nonselective open-channel blocker of ionotropic glutamate (iGlu) receptors. Here, three series of analogues were designed to exploit selectivity among iGlu receptors, taking advantage of a recently developed solid-phase synthetic methodology for the synthesis of ArgTX-636 and analogues. Initially, the importance of secondary amino groups in the polyamine chain was studied by the synthesis of systematically modified ArgTX-636 analogues, which were evaluated for pharmacological activity at NMDA and AMPA receptors. This led to the identification of two compounds with preference for NMDA and AMPA receptors, respectively. These were further elaborated by systematically changing the aromatic headgroup and linker amino acid leading to compounds with increased potency and selectivity for NMDA and AMPA receptors, respectively. Thus, the first structure-activity relationship study of ArgTX-636 has been carried out and has provided lead compounds for probing the ion channel region of iGlu receptors.
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Affiliation(s)
- Mette H Poulsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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50
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Santello M, Volterra A. TNFα in synaptic function: switching gears. Trends Neurosci 2012; 35:638-47. [DOI: 10.1016/j.tins.2012.06.001] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/18/2012] [Accepted: 06/04/2012] [Indexed: 01/17/2023]
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