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Strong TA, Esquivel J, Wang Q, Ledon PJ, Wang H, Gaidosh G, Tse D, Pelaez D. Activation of multiple Eph receptors on neuronal membranes correlates with the onset of optic neuropathy. EYE AND VISION (LONDON, ENGLAND) 2023; 10:42. [PMID: 37779186 PMCID: PMC10544557 DOI: 10.1186/s40662-023-00359-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 09/11/2023] [Indexed: 10/03/2023]
Abstract
BACKGROUND Optic neuropathy is a major cause of irreversible blindness, yet the molecular determinants that contribute to neuronal demise have not been fully elucidated. Several studies have identified 'ephrin signaling' as one of the most dysregulated pathways in the early pathophysiology of optic neuropathy with varied etiologies. Developmentally, gradients in ephrin signaling coordinate retinotopic mapping via repulsive modulation of cytoskeletal dynamics in neuronal membranes. Little is known about the role ephrin signaling plays in the post-natal visual system and its correlation with the onset of optic neuropathy. METHODS Postnatal mouse retinas were collected for mass spectrometry analysis for erythropoietin-producing human hepatocellular (Eph) receptors. Optic nerve crush (ONC) model was employed to induce optic neuropathy, and proteomic changes during the acute phase of neuropathic onset were analyzed. Confocal and super-resolution microscopy determined the cellular localization of activated Eph receptors after ONC injury. Eph receptor inhibitors assessed the neuroprotective effect of ephrin signaling modulation. RESULTS Mass spectrometry revealed expression of seven Eph receptors (EphA2, A4, A5, B1, B2, B3, and B6) in postnatal mouse retinal tissue. Immunoblotting analysis indicated a significant increase in phosphorylation of these Eph receptors 48 h after ONC. Confocal microscopy demonstrated the presence of both subclasses of Eph receptors within the retina. Stochastic optical reconstruction microscopy (STORM) super-resolution imaging combined with optimal transport colocalization analysis revealed a significant co-localization of activated Eph receptors with injured neuronal cells, compared to uninjured neuronal and/or injured glial cells, 48 h post-ONC. Eph receptor inhibitors displayed notable neuroprotective effects for retinal ganglion cells (RGCs) after six days of ONC injury. CONCLUSIONS Our findings demonstrate the functional presence of diverse Eph receptors in the postnatal mammalian retina, capable of modulating multiple biological processes. Pan-Eph receptor activation contributes to the onset of neuropathy in optic neuropathies, with preferential activation of Eph receptors on neuronal processes in the inner retina following optic nerve injury. Notably, Eph receptor activation precedes neuronal loss. We observed a neuroprotective effect on RGCs upon inhibiting Eph receptors. Our study highlights the importance of investigating this repulsive pathway in early optic neuropathies and provides a comprehensive characterization of the receptors present in the developed retina of mice, relevant to both homeostasis and disease processes.
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Affiliation(s)
- Thomas A Strong
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL, 33136, USA
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, USA
| | - Juan Esquivel
- Department of Physics, University of Florida College of Liberal Arts and Sciences, Gainesville, FL, USA
| | - Qikai Wang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL, 33136, USA
| | - Paul J Ledon
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL, 33136, USA
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Hua Wang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL, 33136, USA
| | - Gabriel Gaidosh
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - David Tse
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL, 33136, USA
| | - Daniel Pelaez
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA.
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL, 33136, USA.
- Department of Biomedical Engineering, University of Miami College of Engineering, University of Miami, Coral Gables, FL, USA.
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, USA.
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
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Verma M, Chopra M, Kumar H. Unraveling the Potential of EphA4: A Breakthrough Target and Beacon of Hope for Neurological Diseases. Cell Mol Neurobiol 2023; 43:3375-3391. [PMID: 37477786 DOI: 10.1007/s10571-023-01390-0] [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: 04/22/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023]
Abstract
Erythropoietin-producing hepatocellular carcinoma A4 (EphA4) is a transmembrane receptor protein which is a part of the most prominent family of receptor tyrosine kinases (RTKs). It serves a crucial role in both physiological, biological, and functional states binding with their ligand like Ephrins. Its abundance in the majority of the body's systems has been reported. Moreover, it draws much attention in the CNS since it influences axonal and vascular guidance. Also, it has a widespread role at the pathological state of various CNS disorders. Reports suggest it obstructs axonal regeneration in various neurodegenerative diseases and neurological disorders. Although, neuro-regeneration is still an open challenge to the modern drug discovery community. Hence, in this review, we will provide information about the role of EphA4 in neurological diseases by which it may emerge as a therapeutic target for CNS disease. We will also provide a glance at numerous signaling pathways that activate or inhibit the EphA4-associated biological processes contributing to the course of neurodegenerative diseases. Thus, this work might serve as a basis for futuristic studies that are related to the target-based drug discovery in the field of neuro-regeneration. Pathological and physiological events associated with EphA4 and Ephrin upregulation and interaction.
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Affiliation(s)
- Meenal Verma
- National Institute of Pharmaceutical Education and Research, Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar, Gujarat, 382355, India
| | - Manjeet Chopra
- National Institute of Pharmaceutical Education and Research, Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar, Gujarat, 382355, India
| | - Hemant Kumar
- National Institute of Pharmaceutical Education and Research, Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar, Gujarat, 382355, India.
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3
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Strong TA, Esquivel J, Wang Q, Ledon PJ, Wang H, Gaidosh G, Tse D, Pelaez D. Activation of Multiple Eph Receptors on Neuronal Membranes Correlates with The Onset of Traumatic Optic Neuropathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543735. [PMID: 37333178 PMCID: PMC10274644 DOI: 10.1101/2023.06.05.543735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Optic neuropathy (ON) is a major cause of irreversible blindness, yet the molecular determinants that contribute to neuronal demise have not been fully elucidated. Several studies have identified 'ephrin signaling' as one of the most dysregulated pathways in the early pathophysiology of ON with varied etiologies. Developmentally, gradients in ephrin signaling coordinate retinotopic mapping via repulsive modulation of cytoskeletal dynamics in neuronal membranes. Little is known about the role ephrin signaling played in the post-natal visual system and its correlation with the onset of optic neuropathy. Methods Postnatal mouse retinas were collected for mass spectrometry analysis for Eph receptors. Optic nerve crush (ONC) model was employed to induce optic neuropathy, and proteomic changes during the acute phase of neuropathic onset were analyzed. Confocal and super-resolution microscopy determined the cellular localization of activated Eph receptors after ONC injury. Eph receptor inhibitors assessed the neuroprotective effect of ephrin signaling modulation. Results Mass spectrometry revealed expression of seven Eph receptors (EphA2, A4, A5, B1, B2, B3, and B6) in postnatal mouse retinal tissue. Immunoblotting analysis indicated a significant increase in phosphorylation of these Eph receptors 48 hours after ONC. Confocal microscopy demonstrated the presence of both subclasses of Eph receptors in the inner retinal layers. STORM super-resolution imaging combined with optimal transport colocalization analysis revealed a significant co-localization of activated Eph receptors with injured neuronal processes, compared to uninjured neuronal and/or injured glial cells, 48 hours post-ONC. Eph receptor inhibitors displayed notable neuroprotective effects after 6 days of ONC injury. Conclusions Our findings demonstrate the functional presence of diverse Eph receptors in the postnatal mammalian retina, capable of modulating multiple biological processes. Pan-Eph receptor activation contributes to the onset of neuropathy in ONs, with preferential activation of Eph receptors on neuronal processes in the inner retina following optic nerve injury. Notably, Eph receptor activation precedes neuronal loss. We observed neuroprotective effects upon inhibiting Eph receptors. Our study highlights the importance of investigating this repulsive pathway in early optic neuropathies and provides a comprehensive characterization of the receptors present in the developed retina of mice, relevant to both homeostasis and disease processes.
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Affiliation(s)
- Thomas A. Strong
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Department of Cell Biology, University of Miami Miller School of Medicine
| | - Juan Esquivel
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Qikai Wang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Paul J. Ledon
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Hua Wang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Gabriel Gaidosh
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - David Tse
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Daniel Pelaez
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Dr. Nasser Al-Rashid Orbital Vision Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America
- Department of Biomedical Engineering, University of Miami College of Engineering, University of Miami, Coral Gables, FL, United States of America
- Department of Cell Biology, University of Miami Miller School of Medicine
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, United States of America
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Kowalski EA, Soliman E, Kelly C, Basso EKG, Leonard J, Pridham KJ, Ju J, Cash A, Hazy A, de Jager C, Kaloss AM, Ding H, Hernandez RD, Coleman G, Wang X, Olsen ML, Pickrell AM, Theus MH. Monocyte proinflammatory phenotypic control by ephrin type A receptor 4 mediates neural tissue damage. JCI Insight 2022; 7:e156319. [PMID: 35737458 PMCID: PMC9462496 DOI: 10.1172/jci.insight.156319] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 06/21/2022] [Indexed: 11/29/2022] Open
Abstract
Circulating monocytes have emerged as key regulators of the neuroinflammatory milieu in a number of neuropathological disorders. Ephrin type A receptor 4 (Epha4) receptor tyrosine kinase, a prominent axon guidance molecule, has recently been implicated in the regulation of neuroinflammation. Using a mouse model of brain injury and a GFP BM chimeric approach, we found neuroprotection and a lack of significant motor deficits marked by reduced monocyte/macrophage cortical infiltration and an increased number of arginase-1+ cells in the absence of BM-derived Epha4. This was accompanied by a shift in monocyte gene profile from pro- to antiinflammatory that included increased Tek (Tie2 receptor) expression. Inhibition of Tie2 attenuated enhanced expression of M2-like genes in cultured Epha4-null monocytes/macrophages. In Epha4-BM-deficient mice, cortical-isolated GFP+ monocytes/macrophages displayed a phenotypic shift from a classical to an intermediate subtype, which displayed reduced Ly6chi concomitant with increased Ly6clo- and Tie2-expressing populations. Furthermore, clodronate liposome-mediated monocyte depletion mimicked these effects in WT mice but resulted in attenuation of phenotype in Epha4-BM-deficient mice. This demonstrates that monocyte polarization not overall recruitment dictates neural tissue damage. Thus, coordination of monocyte proinflammatory phenotypic state by Epha4 is a key regulatory step mediating brain injury.
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Affiliation(s)
- Elizabeth A. Kowalski
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Colin Kelly
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
- School of Neuroscience, and
| | | | - John Leonard
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Kevin J. Pridham
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Jing Ju
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Alison Cash
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Amanda Hazy
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Caroline de Jager
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Hanzhang Ding
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | - Raymundo D. Hernandez
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | | | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | | | | | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
- School of Neuroscience, and
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
- Center for Engineered Health, Virginia Tech, Blacksburg, Virginia, USA
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5
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Li Y, Su P, Chen Y, Nie J, Yuan TF, Wong AH, Liu F. The Eph receptor A4 plays a role in demyelination and depression-related behavior. J Clin Invest 2022; 132:e152187. [PMID: 35271507 PMCID: PMC9012277 DOI: 10.1172/jci152187] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 03/08/2022] [Indexed: 11/22/2022] Open
Abstract
Proper myelination of axons is crucial for normal sensory, motor, and cognitive function. Abnormal myelination is seen in brain disorders such as major depressive disorder (MDD), but the molecular mechanisms connecting demyelination with the pathobiology remain largely unknown. We observed demyelination and synaptic deficits in mice exposed to either chronic, unpredictable mild stress (CUMS) or LPS, 2 paradigms for inducing depression-like states. Pharmacological restoration of myelination normalized both synaptic deficits and depression-related behaviors. Furthermore, we found increased ephrin A4 receptor (EphA4) expression in the excitatory neurons of mice subjected to CUMS, and shRNA knockdown of EphA4 prevented demyelination and depression-like behaviors. These animal data are consistent with the decrease in myelin basic protein and the increase in EphA4 levels we observed in postmortem brain samples from patients with MDD. Our results provide insights into the etiology of depressive symptoms in some patients and suggest that inhibition of EphA4 or the promotion of myelination could be a promising strategy for treating depression.
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Affiliation(s)
- Yuan Li
- Shanghai Mental Health Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
| | - Ping Su
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health
| | - Yuxiang Chen
- Shanghai Mental Health Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
| | - Jing Nie
- Shanghai Mental Health Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
| | - Ti-Fei Yuan
- Shanghai Mental Health Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
| | - Albert H.C. Wong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health
- Departments of Psychiatry
- Institutes of Medical Science
- Pharmacology and Toxicology, and
| | - Fang Liu
- Shanghai Mental Health Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health
- Departments of Psychiatry
- Institutes of Medical Science
- Physiology at the University of Toronto, Toronto, Ontario, Canada
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6
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Rani A, Jakhmola S, Karnati S, Parmar HS, Chandra Jha H. Potential entry receptors for human γ-herpesvirus into epithelial cells: A plausible therapeutic target for viral infections. Tumour Virus Res 2021; 12:200227. [PMID: 34800753 PMCID: PMC8628264 DOI: 10.1016/j.tvr.2021.200227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/28/2021] [Accepted: 11/15/2021] [Indexed: 12/14/2022] Open
Abstract
Herpesviruses are ubiquitous viruses, specifically the Epstein Barr virus (EBV). EBV and Kaposi's sarcoma-associated herpesvirus (KSHV) establish their latency for a long period in B-cells and their reactivation instigates dreadful diseases from cancer to neurological modalities. The envelope glycoprotein of these viruses makes an attachment with several host receptors. For instance; glycoprotein 350/220, gp42, gHgL and gB of EBV establish an attachment with CD21, HLA-DR, Ephs, and other receptor molecules to hijack the B- and epithelial cell machinery. Ephs are reported recently as potent receptors for EBV entry into epithelial cells. Eph receptors play a role in the maintenance and control of various cellular processes including morphology, adhesion, proliferation, survival and differentiation. Alterations in the structure and expression of Eph and ephrin (Eph ligands) molecules is entangled with various pathologies including tumours and neurological complications. Along with Eph, integrins, NRP, NMHC are also key players in viral infections as they are possibly involved in viral transmission, replication and persistence. Contrarily, KSHV gH is known to interact with EphA2 and -A4 molecules, whereas in the case of EBV only EphA2 receptors are being reported to date. The ELEFN region of KSHV gH was involved in the interaction with EphA2, however, the interacting region of EBV gH is elusive. Further, the gHgL of KSHV and EBV form a complex with the EphA2 ligand-binding domain (LBD). Primarily by using gL both KSHV and EBV gHgL bind to the peripheral regions of LBD. In addition to γ-herpesviruses, several other viruses like Nipah virus, Cedar virus, Hepatitis C virus and Rhesus macaque rhadinovirus (RRV) also access the host cells via Eph receptors. Therefore, we summarise the possible roles of Eph and ephrins in virus-mediated infection and these molecules could serve as potential therapeutic targets. Crucial understanding of human γ-herpesviruses entry mechanism. Eph receptors relate to changed biomolecular profile upon EBV infection. EBV association with neurological disorders. Eph receptors could be an elegant drug for human γ-herpesviruses.
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Affiliation(s)
- Annu Rani
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India
| | - Shweta Jakhmola
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India
| | - Srikanth Karnati
- Department of Medical Cell Biology, Julius Maximilians University, Wuerzburg, Germany
| | - Hamendra Singh Parmar
- School of Biotechnology, Devi Ahilya University, Takshashila Campus, Khandwa Road, Indore, 452001, MP, India
| | - Hem Chandra Jha
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India.
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Soliman E, Mills J, Ju J, Kaloss AM, Basso EKG, Groot N, Kelly C, Kowalski EA, Elhassanny M, Chen M, Wang X, Theus MH. Conditional Deletion of EphA4 on Cx3cr1-Expressing Microglia Fails to Influence Histopathological Outcome and Blood Brain Barrier Disruption Following Brain Injury. Front Mol Neurosci 2021; 14:747770. [PMID: 34630039 PMCID: PMC8497746 DOI: 10.3389/fnmol.2021.747770] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
Erythropoietin-producing human hepatocellular receptors play a major role in central nervous system injury. Preclinical and clinical studies revealed the upregulation of erythropoietin-producing human hepatocellular A4 (EphA4) receptors in the brain after acute traumatic brain injury. We have previously reported that Cx3cr1-expressing cells in the peri-lesion show high levels of EphA4 after the induction of controlled cortical impact (CCI) injury in mice. Cx3cr1 is a fractalkine receptor expressed on both resident microglia and peripheral-derived macrophages. The current study aimed to determine the role of microglial-specific EphA4 in CCI-induced damage. We used Cx3cr1 CreER/+ knock-in/knock-out mice, which express EYFP in Cx3cr1-positive cells to establish microglia, EphA4-deficient mice following 1-month tamoxifen injection. Consistent with our previous findings, induction of CCI in wild-type (WT) Cx3cr1 CreER/+ EphA4 +/+ mice increased EphA4 expression on EYFP-positive cells in the peri-lesion. To distinguish between peripheral-derived macrophages and resident microglia, we exploited GFP bone marrow-chimeric mice and found that CCI injury increased EphA4 expression in microglia (TMEM119+GFP-) using immunohistochemistry. Using Cx3cr1 CreER/+ EphA4 f/f (KO) mice, we observed that the EphA4 mRNA transcript was undetected in microglia but remained present in whole blood when compared to WT. Finally, we found no difference in lesion volume or blood-brain barrier (BBB) disruption between WT and KO mice at 3 dpi. Our data demonstrate a nonessential role of microglial EphA4 in the acute histopathological outcome in response to CCI.
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Affiliation(s)
- Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Jatia Mills
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Jing Ju
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Alexandra M Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | | | - Nathalie Groot
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Colin Kelly
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Elizabeth A Kowalski
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Mohamed Elhassanny
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Michael Chen
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States.,School of Neuroscience, Virginia Tech, Blacksburg, VA, United States.,Center for Engineered Health, Virginia Tech, Blacksburg, VA, United States
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8
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Lusardi TA, Sandau US, Sakhanenko NA, Baker SCB, Wiedrick JT, Lapidus JA, Raskind MA, Li G, Peskind ER, Galas DJ, Quinn JF, Saugstad JA. Cerebrospinal Fluid MicroRNA Changes in Cognitively Normal Veterans With a History of Deployment-Associated Mild Traumatic Brain Injury. Front Neurosci 2021; 15:720778. [PMID: 34580583 PMCID: PMC8463659 DOI: 10.3389/fnins.2021.720778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/27/2021] [Indexed: 01/09/2023] Open
Abstract
A history of traumatic brain injury (TBI) increases the odds of developing Alzheimer's disease (AD). The long latent period between injury and dementia makes it difficult to study molecular changes initiated by TBI that may increase the risk of developing AD. MicroRNA (miRNA) levels are altered in TBI at acute times post-injury (<4 weeks), and in AD. We hypothesized that miRNA levels in cerebrospinal fluid (CSF) following TBI in veterans may be indicative of increased risk for developing AD. Our population of interest is cognitively normal veterans with a history of one or more mild TBI (mTBI) at a chronic time following TBI. We measured miRNA levels in CSF from three groups of participants: (1) community controls with no lifetime history of TBI (ComC); (2) deployed Iraq/Afghanistan veterans with no lifetime history of TBI (DepC), and (3) deployed Iraq/Afghanistan veterans with a history of repetitive blast mTBI (DepTBI). CSF samples were collected at the baseline visit in a longitudinal, multimodal assessment of Gulf War veterans, and represent a heterogenous group of male veterans and community controls. The average time since the last blast mTBI experienced was 4.7 ± 2.2 years [1.5 - 11.5]. Statistical analysis of TaqManTM miRNA array data revealed 18 miRNAs with significant differential expression in the group comparisons: 10 between DepTBI and ComC, 7 between DepC and ComC, and 8 between DepTBI and DepC. We also identified 8 miRNAs with significant differential detection in the group comparisons: 5 in DepTBI vs. ComC, 3 in DepC vs. ComC, and 2 in DepTBI vs. DepC. When we applied our previously developed multivariable dependence analysis, we found 13 miRNAs (6 of which are altered in levels or detection) that show dependencies with participant phenotypes, e.g., ApoE. Target prediction and pathway analysis with miRNAs differentially expressed in DepTBI vs. either DepC or ComC identified canonical pathways highly relevant to TBI including senescence and ephrin receptor signaling, respectively. This study shows that both TBI and deployment result in persistent changes in CSF miRNA levels that are relevant to known miRNA-mediated AD pathology, and which may reflect early events in AD.
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Affiliation(s)
- Theresa A Lusardi
- Knight Cancer Institute, Cancer Early Detection Advanced Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Ursula S Sandau
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, United States
| | | | - Sarah Catherine B Baker
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, United States
| | - Jack T Wiedrick
- Biostatistics & Design Program, Oregon Health & Science University, Portland, OR, United States
| | - Jodi A Lapidus
- Biostatistics & Design Program, Oregon Health & Science University, Portland, OR, United States
| | - Murray A Raskind
- Northwest Mental Illness, Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, United States
| | - Ge Li
- Northwest Mental Illness, Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, United States.,Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States
| | - Elaine R Peskind
- Northwest Mental Illness, Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, United States
| | - David J Galas
- Pacific Northwest Research Institute, Seattle, WA, United States
| | - Joseph F Quinn
- Department of Neurology, Oregon Health & Science University, Portland, OR, United States.,Parkinson Center and Movement Disorders Program, School of Medicine, Oregon Health & Science University, Portland, OR, United States.,Portland VAMC Parkinson's Disease Research, Education, and Clinical Center, Portland, OR, United States
| | - Julie A Saugstad
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, United States
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9
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Baggio C, Kulinich A, Dennys CN, Rodrigo R, Meyer K, Ethell I, Pellecchia M. NMR-Guided Design of Potent and Selective EphA4 Agonistic Ligands. J Med Chem 2021; 64:11229-11246. [PMID: 34293864 DOI: 10.1021/acs.jmedchem.1c00608] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this paper, we applied an innovative nuclear magnetic resonance (NMR)-guided screening and ligand design approach, named focused high-throughput screening by NMR (fHTS by NMR), to derive potent, low-molecular-weight ligands capable of mimicking interactions elicited by ephrin ligands on the receptor tyrosine kinase EphA4. The agents bind with nanomolar affinity, trigger receptor activation in cellular assays with motor neurons, and provide remarkable motor neuron protection from amyotrophic lateral sclerosis (ALS) patient-derived astrocytes. Structural studies on the complex between EphA4 ligand-binding domain and a most active agent provide insights into the mechanism of the agents at a molecular level. Together with preliminary in vivo pharmacology studies, the data form a strong foundation for the translation of these agents for the treatment of ALS and potentially other human diseases.
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Affiliation(s)
- Carlo Baggio
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Anna Kulinich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Cassandra N Dennys
- Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, United States
| | - Rochelle Rodrigo
- Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, United States
| | - Kathrin Meyer
- Nationwide Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, United States
| | - Iryna Ethell
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Maurizio Pellecchia
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
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10
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Teo L, Boghdadi AG, Homman-Ludiye J, Mundinano IC, Kwan WC, Bourne JA. Replicating infant-specific reactive astrocyte functions in the injured adult brain. Prog Neurobiol 2021; 204:102108. [PMID: 34147584 DOI: 10.1016/j.pneurobio.2021.102108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 06/10/2021] [Accepted: 06/15/2021] [Indexed: 11/29/2022]
Abstract
Infants and adults respond differently to brain injuries. Specifically, improved neuronal sparing along with reduced astrogliosis and glial scarring often observed earlier in life, likely contributes to improved long-term outcomes. Understanding the underlying mechanisms could enable the recapitulation of neuroprotective effects, observed in infants, to benefit adults after brain injuries. We reveal that in primates, Eph/ ephrin signaling contributes to age-dependent reactive astrocyte behavior. Ephrin-A5 expression on astrocytes was more protracted in adults, whereas ephrin-A1 was only expressed on infant astrocytes. Furthermore, ephrin-A5 exacerbated major hallmarks of astrocyte reactivity via EphA2 and EphA4 receptors, which was subsequently alleviated by ephrin-A1. Rather than suppressing reactivity, ephrin-A1 signaling shifted astrocytes towards GAP43+ neuroprotection, accounting for improved neuronal sparing in infants. Reintroducing ephrin-A1 after middle-aged focal ischemic injury significantly attenuated glial scarring, improved neuronal sparing and preserved circuitry. Therefore, beneficial infant mechanisms can be recapitulated in adults to improve outcomes after CNS injuries.
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Affiliation(s)
- Leon Teo
- Australian Regenerative Medicine Institute, 15 Innovation Walk, Monash University, Clayton VIC, 3800, Australia
| | - Anthony G Boghdadi
- Australian Regenerative Medicine Institute, 15 Innovation Walk, Monash University, Clayton VIC, 3800, Australia
| | - Jihane Homman-Ludiye
- Australian Regenerative Medicine Institute, 15 Innovation Walk, Monash University, Clayton VIC, 3800, Australia
| | - Inaki-Carril Mundinano
- Australian Regenerative Medicine Institute, 15 Innovation Walk, Monash University, Clayton VIC, 3800, Australia
| | - William C Kwan
- Australian Regenerative Medicine Institute, 15 Innovation Walk, Monash University, Clayton VIC, 3800, Australia
| | - James A Bourne
- Australian Regenerative Medicine Institute, 15 Innovation Walk, Monash University, Clayton VIC, 3800, Australia.
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11
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EphA4 is highly expressed in the atria of heart and its deletion leads to atrial hypertrophy and electrocardiographic abnormalities in rats. Life Sci 2021; 278:119595. [PMID: 33974931 DOI: 10.1016/j.lfs.2021.119595] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/25/2021] [Accepted: 05/03/2021] [Indexed: 01/12/2023]
Abstract
AIMS EphA4 is a member of the Eph receptor family, and expressed mainly in central nervous system (CNS), which is involved in CNS development and multiple diseases. Due to the variability in EphA4 expression, we wondered if EphA4 is expressed in other tissues, and what role does EphA4 play? MATERIALS AND METHODS We generated an EphA4 knockout (KO) rat line with red fluorescent marker protein encoded by the mCherry cassette inserted downstream of the EphA4 promoter as a reporter. Using this system, we observed high expression of EphA4 in the heart atria and in the brain. KEY FINDINGS EphaA4 KO rats (EphA4-/-) developed obvious atrial hypertrophy with an increased atria-to-heart weight ratio and atrial cardiomyocyte cross-sectional area at six months of age. EphA4-/- rats had reduced atrial end diastolic volume (EDV), atrial ejection fraction (EF) and left ventricular EF. They also exhibited increased amplitude of QRS complexes and QT intervals, with invisible p waves. RNA sequencing revealed that EphA4 KO altered the transcription of multiple genes involved in regulation of transcription and translation, ion binding, metabolism and cell adhesion. Deletion of EphA4 reduced IGF1 mRNA and protein expression, which is involved in cardiac remodeling. SIGNIFICANCE Our data demonstrated that EphA4 was highly expressed in the atria and its deletion caused atrial dysfunction. Our findings also suggested that the EphA4 KO rat could be a potential model for studies on atrial remodeling.
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12
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Xu LJ, Gao F, Cheng S, Zhou ZX, Li F, Miao Y, Niu WR, Yuan F, Sun XH, Wang Z. Activated ephrinA3/EphA4 forward signaling induces retinal ganglion cell apoptosis in experimental glaucoma. Neuropharmacology 2020; 178:108228. [PMID: 32745487 DOI: 10.1016/j.neuropharm.2020.108228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/16/2020] [Accepted: 07/01/2020] [Indexed: 12/12/2022]
Abstract
Previous studies have demonstrated that EphA4 participates in neuronal injury, and there is a strong interaction between ephrinA3 and EphA4. In this study, we showed that in a rat chronic ocular hypertension (COH) experimental glaucoma model, expression of EphA4 and ephrinA3 proteins was increased in retinal cells, including retinal ganglion cells (RGCs) and Müller cells, which may result in ephrinA3/EphA4 forward signaling activation on RGCs, as evidenced by increased p-EphA4/EphA4 ratio. Intravitreal injection of ephrinA3-Fc, an activator of EphA4, mimicked the effect of COH on p-EphA4/EphA4 and induced an increase in TUNEL-positive signals in normal retinas, which was accompanied by dendritic spine retraction and thinner dendrites in RGCs. Furthermore, Intravitreal injection of ephrinA3-Fc increased the levels of phosphorylated src and GluA2 (p-src and p-GluA2). Co-immunoprecipitation assay demonstrated interactions between EphA4, p-src and GluA2. Intravitreal injection of ephrinA3-Fc reduced the expression of GluA2 proteins on the surface of normal retinal cells, which was prevented by intravitreal injection of PP2, an inhibitor of src-family tyrosine kinases. Pre-injection of PP2 or the Ca2+-permeable GluA2-lacking AMPA receptor inhibitor Naspm significantly and partially reduced the number of TUNEL-positive RGCs in the ephrinA3-Fc-injected and COH retinas. Our results suggest that activated ephrinA3/EphA4 forward signaling promoted GluA2 endocytosis, then resulted in dendritic spine retraction of RGCs, thus contributing to RGC apoptosis in COH rats. Attenuation of the strength of ephrinA/EphA signaling in an appropriate manner may be an effective way for preventing the loss of RGCs in glaucoma.
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Affiliation(s)
- Lin-Jie Xu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Feng Gao
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Key Laboratory of Visual Impairment and Restoration, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200031, China
| | - Shuo Cheng
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Zhi-Xin Zhou
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Fang Li
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Yanying Miao
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Wei-Ran Niu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Fei Yuan
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xing-Huai Sun
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Key Laboratory of Visual Impairment and Restoration, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200031, China.
| | - Zhongfeng Wang
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
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13
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Kim MJ, Son JY, Ju JS, Ahn DK. Early Blockade of EphA4 Pathway Reduces Trigeminal Neuropathic Pain. J Pain Res 2020; 13:1173-1183. [PMID: 32547180 PMCID: PMC7250313 DOI: 10.2147/jpr.s249185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/29/2020] [Indexed: 12/31/2022] Open
Abstract
Background Although the Eph receptor plays an important role in the development of neuropathic pain following nerve injury, there has been no evidence of the participation of the ephrin A4 receptor (EphA4) in the development of trigeminal neuropathic pain. The present study investigated the role of EphA4 in central nociceptive processing in rats with inferior alveolar nerve injury. Materials and Methods Male Sprague-Dawley rats were used in all our experiments. A rat model for trigeminal neuropathic pain was produced using malpositioned dental implants. The left mandibular second molar was extracted under anesthesia, followed by the placement of a miniature dental implant to injure the inferior alveolar nerve. Results Our current findings show that nerve injury induced by malpositioned dental implants evokes significant mechanical allodynia and up-regulation of EphA4 expression in the ipsilateral trigeminal subnucleus caudalis. Although daily treatment with EphA4-Fc, an EphA4 antagonist, did not produce prolonged anti-allodynic effects after the chronic neuropathic pain had been already established, an early treatment protocol with repeated EphA4-Fc administration significantly attenuated mechanical allodynia before initiation of chronic neuropathic pain. Finally, we confirmed the participation of the central EphA4 pathway in the development of trigeminal neuropathic pain by reducing EphA4 expression using EphA4 siRNA. This suppression of EphA4 produced significantly prolonged anti-allodynic effects. Conclusion These results suggest that early blockade of central EphA4 signaling provides a new therapeutic target for the treatment of trigeminal neuropathic pain.
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Affiliation(s)
- Min-Ji Kim
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Jo-Young Son
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Jin-Sook Ju
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Dong-Kuk Ahn
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea
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14
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Peripheral loss of EphA4 ameliorates TBI-induced neuroinflammation and tissue damage. J Neuroinflammation 2019; 16:210. [PMID: 31711546 PMCID: PMC6844068 DOI: 10.1186/s12974-019-1605-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/26/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The continuum of pro- and anti-inflammatory response elicited by traumatic brain injury (TBI) is suggested to play a key role in the outcome of TBI; however, the underlying mechanisms remain ill -defined. METHODS Here, we demonstrate that using bone marrow chimeric mice and systemic inhibition of EphA4 receptor shifts the pro-inflammatory milieu to pro-resolving following acute TBI. RESULTS EphA4 expression is increased in the injured cortex as early as 2 h post-TBI and on CX3CR1gfp-positive cells in the peri-lesion. Systemic inhibition or genetic deletion of EphA4 significantly reduced cortical lesion volume and shifted the inflammatory profile of peripheral-derived immune cells to pro-resolving in the damaged cortex. These findings were consistent with in vitro studies showing EphA4 inhibition or deletion altered the inflammatory state of LPS-stimulated monocyte/macrophages towards anti-inflammatory. Phosphoarray analysis revealed that EphA4 may regulate pro-inflammatory gene expression by suppressing the mTOR, Akt, and NF-κB pathways. Our human metadata analysis further demonstrates increased EPHA4 and pro-inflammatory gene expression, which correlates with reduced AKT concurrent with increased brain injury severity in patients. CONCLUSIONS Overall, these findings implicate EphA4 as a novel mediator of cortical tissue damage and neuroinflammation following TBI.
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15
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Fraunberger E, Esser MJ. Neuro-Inflammation in Pediatric Traumatic Brain Injury-from Mechanisms to Inflammatory Networks. Brain Sci 2019; 9:E319. [PMID: 31717597 PMCID: PMC6895990 DOI: 10.3390/brainsci9110319] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 12/12/2022] Open
Abstract
Compared to traumatic brain injury (TBI) in the adult population, pediatric TBI has received less research attention, despite its potential long-term impact on the lives of many children around the world. After numerous clinical trials and preclinical research studies examining various secondary mechanisms of injury, no definitive treatment has been found for pediatric TBIs of any severity. With the advent of high-throughput and high-resolution molecular biology and imaging techniques, inflammation has become an appealing target, due to its mixed effects on outcome, depending on the time point examined. In this review, we outline key mechanisms of inflammation, the contribution and interactions of the peripheral and CNS-based immune cells, and highlight knowledge gaps pertaining to inflammation in pediatric TBI. We also introduce the application of network analysis to leverage growing multivariate and non-linear inflammation data sets with the goal to gain a more comprehensive view of inflammation and develop prognostic and treatment tools in pediatric TBI.
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Affiliation(s)
- Erik Fraunberger
- Alberta Children’s Hospital Research Institute, Calgary, AB T3B 6A8, Canada;
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Michael J. Esser
- Alberta Children’s Hospital Research Institute, Calgary, AB T3B 6A8, Canada;
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Pediatrics, Cumming School Of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
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16
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Bieler L, Vogl M, Kirchinger M, Urmann C, Riepl H, Bandtlow C, Klimaschewski L, Aigner L, Couillard-Despres S. The Prenylflavonoid ENDF1 Overrules Central Nervous System Growth Inhibitors and Facilitates Regeneration of DRG Neurons. Front Cell Neurosci 2019; 13:332. [PMID: 31396054 PMCID: PMC6668039 DOI: 10.3389/fncel.2019.00332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 07/04/2019] [Indexed: 01/04/2023] Open
Abstract
Restoration of neuronal connectivity after lesion of the central nervous system, such as spinal cord injury, is one of the biggest challenges in modern medicine. In particular, the accumulation of axon growth inhibitory factors at the site of injury constitutes a major obstacle to structural and thus functional repair. We previously investigated a group of prenylflavonoids derived from hops for their capacity to promote neuroregeneration. We identified a molecule called ENDF1 that was very potent to enhance regrowth and branching of neurites from dorsal root ganglion neurons in culture on growth promoting substrates. In the present study, we investigated ENDF1’s capacity to promote regeneration of rat dorsal root ganglion neurons in vitro in the presence of three main components of the extracellular matrix acting as axon growth inhibitors: Semaphorin 3A, Ephrin A4 and mixed chondroitin sulfate proteoglycans. We report that ENDF1 application significantly promoted the percentages of sensory neurons able to regrow their neurites regardless of the presence of those inhibitors, and this to an extent similar to the one obtained after NGF treatment. Moreover, ENDF1 strongly enhanced the total neurite length and the complexity of neurites extending from neurons challenged with axon growth inhibitors. Although the impact of NGF and ENDF1 on the regeneration of neurons was similar, the activity of ENDF1 was not mediated by signaling through the TrkA receptor, indicating that each molecule act through different signaling pathways. In addition, ENDF1 did not decrease the phosphorylation of cofilin, a downstream effector of the regeneration-associated RhoA/ROCK signaling pathway. Hence, ENDF1 is a potent pro-neuroregenerative factors that could help in identifying new efficient targets for regenerative therapies of the nervous system.
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Affiliation(s)
- Lara Bieler
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria
| | - Michael Vogl
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria
| | - Michael Kirchinger
- Organic-Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Straubing, Germany.,TUM Campus Straubing, Straubing, Germany
| | - Corinna Urmann
- Organic-Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Straubing, Germany.,TUM Campus Straubing, Straubing, Germany
| | - Herbert Riepl
- Organic-Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Straubing, Germany.,TUM Campus Straubing, Straubing, Germany
| | - Christine Bandtlow
- Division of Neurobiochemistry, Innsbruck Medical University, Innsbruck, Austria
| | - Lars Klimaschewski
- Department of Anatomy, Histology and Embryology, Division of Neuroanatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
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17
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Teng S, Palmieri A, Maita I, Zheng C, Das G, Park J, Zhou R, Alder J, Thakker-Varia S. Inhibition of EphA/Ephrin-A signaling using genetic and pharmacologic approaches improves recovery following traumatic brain injury in mice. Brain Inj 2019; 33:1385-1401. [DOI: 10.1080/02699052.2019.1641622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Shavonne Teng
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Alicia Palmieri
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Isabella Maita
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Cynthia Zheng
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Gitanjali Das
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, USA
| | - Juyeon Park
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Renping Zhou
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, USA
| | - Janet Alder
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Smita Thakker-Varia
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
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18
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Darling TK, Lamb TJ. Emerging Roles for Eph Receptors and Ephrin Ligands in Immunity. Front Immunol 2019; 10:1473. [PMID: 31333644 PMCID: PMC6620610 DOI: 10.3389/fimmu.2019.01473] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 06/13/2019] [Indexed: 12/30/2022] Open
Abstract
Eph receptors are the largest family of receptor tyrosine kinases and mediate a myriad of essential processes in humans from embryonic development to adult tissue homeostasis through interactions with membrane-bound ephrin ligands. The ubiquitous expression of Eph receptors and ephrin ligands among the cellular players of the immune system underscores the importance of these molecules in orchestrating an optimal immune response. This review provides an overview of the various roles of Eph receptors and ephrin ligands in immune cell development, activation, and migration. We also discuss the role of Eph receptors in disease pathogenesis as well as the implications of Eph receptors as future immunotherapy targets. Given the diverse and critical roles of Eph receptors and ephrin ligands throughout the immune system during both resting and activated states, this review aims to highlight the critical yet underappreciated roles of this family of signaling molecules in the immune system.
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Affiliation(s)
- Thayer K Darling
- Immunology and Molecular Pathogenesis Program, Emory University Laney Graduate School, Atlanta, GA, United States.,Department of Pathology, University of Utah, Salt Lake City, UT, United States
| | - Tracey J Lamb
- Department of Pathology, University of Utah, Salt Lake City, UT, United States
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19
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STING-mediated type-I interferons contribute to the neuroinflammatory process and detrimental effects following traumatic brain injury. J Neuroinflammation 2018; 15:323. [PMID: 30463579 PMCID: PMC6247615 DOI: 10.1186/s12974-018-1354-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/30/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) represents a major cause of disability and death worldwide with sustained neuroinflammation and autophagy dysfunction contributing to the cellular damage. Stimulator of interferon genes (STING)-induced type-I interferon (IFN) signalling is known to be essential in mounting the innate immune response against infections and cell injury in the periphery, but its role in the CNS remains unclear. We previously identified the type-I IFN pathway as a key mediator of neuroinflammation and neuronal cell death in TBI. However, the modulation of the type-I IFN and neuroinflammatory responses by STING and its contribution to autophagy and neuronal cell death after TBI has not been explored. METHODS C57BL/6J wild-type (WT) and STING-/- mice (8-10-week-old males) were subjected to controlled cortical impact (CCI) surgery and brains analysed by QPCR, Western blot and immunohistochemical analyses at 2 h or 24 h. STING expression was also analysed by QPCR in post-mortem human brain samples. RESULTS A significant upregulation in STING expression was identified in late trauma human brain samples that was confirmed in wild-type mice at 2 h and 24 h after CCI. This correlated with an elevated pro-inflammatory cytokine profile with increased TNF-α, IL-6, IL-1β and type-I IFN (IFN-α and IFN-β) levels. This expression was suppressed in the STING-/- mice with a smaller lesion volume in the knockout animals at 24 h post CCI. Wild-type mice also displayed increased levels of autophagy markers, LC3-II, p62 and LAMP2 after TBI; however, STING-/- mice showed reduced LAMP2 expression suggesting a role for STING in driving dysfunctional autophagy after TBI. CONCLUSION Our data implicates a detrimental role for STING in mediating the TBI-induced neuroinflammatory response and autophagy dysfunction, potentially identifying a new therapeutic target for reducing cellular damage in TBI.
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20
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Sharma P, Debinski W. Receptor-Targeted Glial Brain Tumor Therapies. Int J Mol Sci 2018; 19:E3326. [PMID: 30366424 PMCID: PMC6274942 DOI: 10.3390/ijms19113326] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/16/2018] [Accepted: 10/19/2018] [Indexed: 12/24/2022] Open
Abstract
Among primary brain tumors, malignant gliomas are notably difficult to manage. The higher-grade tumors represent an unmet need in medicine. There have been extensive efforts to implement receptor-targeted therapeutic approaches directed against gliomas. These approaches include immunotherapies, such as vaccines, adoptive immunotherapy, and passive immunotherapy. Targeted cytotoxic radio energy and pro-drug activation have been designed specifically for brain tumors. The field of targeting through receptors progressed significantly with the discovery of an interleukin 13 receptor alpha 2 (IL-13RA2) as a tumor-associated receptor over-expressed in most patients with glioblastoma (GBM) but not in normal brain. IL-13RA2 has been exploited in novel experimental therapies with very encouraging clinical responses. Other receptors are specifically over-expressed in many patients with GBM, such as EphA2 and EphA3 receptors, among others. These findings are important in view of the heterogeneity of GBM tumors and multiple tumor compartments responsible for tumor progression and resistance to therapies. The combined targeting of multiple receptors in different tumor compartments should be a preferred way to design novel receptor-targeted therapeutic approaches in gliomas.
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Affiliation(s)
- Puja Sharma
- Brain Tumor Center of Excellence, Department of Cancer Biology, Wake Forest University School of Medicine, Comprehensive Cancer Center of Wake Forest Baptist Medical Center, 1 Medical Center Boulevard, Winston-Salem, NC 27157, USA.
| | - Waldemar Debinski
- Brain Tumor Center of Excellence, Department of Cancer Biology, Wake Forest University School of Medicine, Comprehensive Cancer Center of Wake Forest Baptist Medical Center, 1 Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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21
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Ling KK, Jackson M, Alkam D, Liu D, Allaire N, Sun C, Kiaei M, McCampbell A, Rigo F. Antisense-mediated reduction of EphA4 in the adult CNS does not improve the function of mice with amyotrophic lateral sclerosis. Neurobiol Dis 2018. [PMID: 29518482 DOI: 10.1016/j.nbd.2018.03.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal adult onset motor neuron disease characterized by progressive denervation and subsequent motor impairment. EphA4, a negative regulator of axonal growth, was recently identified as a genetic modifier in fish and rodent models of ALS. To evaluate the therapeutic potential of EphA4 for ALS, we examined the effect of CNS-directed EphA4 reduction in preclinical mouse models of ALS, and assessed if the levels of EPHA4 mRNA in blood correlate with disease onset and progression in human ALS patients. We developed antisense oligonucleotides (ASOs) to specifically reduce the expression of EphA4 in the central nervous system (CNS) of adult mice. Intracerebroventricular administration of an Epha4-ASO in wild-type mice inhibited Epha4 mRNA and protein in the brain and spinal cord, and promoted re-innervation and functional recovery after sciatic nerve crush. In contrast, lowering of EphA4 in the CNS of two mouse models of ALS (SOD1G93A and PFN1G118V) did not improve their motor function or survival. Furthermore, the level of EPHA4 mRNA in human blood correlated weakly with age of disease onset, and it was not a significant predictor of disease progression as measured by ALS Functional Rating Scores (ALSFRS). Our data demonstrates that lowering EphA4 in the adult CNS may not be a stand-alone viable strategy for treating ALS.
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Affiliation(s)
| | | | - Duah Alkam
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | | | | | - Mahmoud Kiaei
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA, USA.
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22
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Hillen AEJ, Burbach JPH, Hol EM. Cell adhesion and matricellular support by astrocytes of the tripartite synapse. Prog Neurobiol 2018; 165-167:66-86. [PMID: 29444459 DOI: 10.1016/j.pneurobio.2018.02.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/25/2017] [Accepted: 02/07/2018] [Indexed: 12/18/2022]
Abstract
Astrocytes contribute to the formation, function, and plasticity of synapses. Their processes enwrap the neuronal components of the tripartite synapse, and due to this close interaction they are perfectly positioned to modulate neuronal communication. The interaction between astrocytes and synapses is facilitated by cell adhesion molecules and matricellular proteins, which have been implicated in the formation and functioning of tripartite synapses. The importance of such neuron-astrocyte integration at the synapse is underscored by the emerging role of astrocyte dysfunction in synaptic pathologies such as autism and schizophrenia. Here we review astrocyte-expressed cell adhesion molecules and matricellular molecules that play a role in integration of neurons and astrocytes within the tripartite synapse.
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Affiliation(s)
- Anne E J Hillen
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Department of Pediatrics/Child Neurology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - J Peter H Burbach
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1098 XH Amsterdam, The Netherlands; Department of Neuroimmunology, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands.
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23
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Schoonaert L, Rué L, Roucourt B, Timmers M, Little S, Chávez-Gutiérrez L, Dewilde M, Joyce P, Curnock A, Weber P, Haustraete J, Hassanzadeh-Ghassabeh G, De Strooper B, Van Den Bosch L, Van Damme P, Lemmens R, Robberecht W. Identification and characterization of Nanobodies targeting the EphA4 receptor. J Biol Chem 2017; 292:11452-11465. [PMID: 28526745 PMCID: PMC5500810 DOI: 10.1074/jbc.m116.774141] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/16/2017] [Indexed: 12/14/2022] Open
Abstract
The ephrin receptor A4 (EphA4) is one of the receptors in the ephrin system that plays a pivotal role in a variety of cell-cell interactions, mostly studied during development. In addition, EphA4 has been found to play a role in cancer biology as well as in the pathogenesis of several neurological disorders such as stroke, spinal cord injury, multiple sclerosis, amyotrophic lateral sclerosis (ALS), and Alzheimer's disease. Pharmacological blocking of EphA4 has been suggested to be a therapeutic strategy for these disorders. Therefore, the aim of our study was to generate potent and selective Nanobodies against the ligand-binding domain of the human EphA4 receptor. We identified two Nanobodies, Nb 39 and Nb 53, that bind EphA4 with affinities in the nanomolar range. These Nanobodies were most selective for EphA4, with residual binding to EphA7 only. Using Alphascreen technology, we found that both Nanobodies displaced all known EphA4-binding ephrins from the receptor. Furthermore, Nb 39 and Nb 53 inhibited ephrin-induced phosphorylation of the EphA4 protein in a cell-based assay. Finally, in a cortical neuron primary culture, both Nanobodies were able to inhibit endogenous EphA4-mediated growth-cone collapse induced by ephrin-B3. Our results demonstrate the potential of Nanobodies to target the ligand-binding domain of EphA4. These Nanobodies may deserve further evaluation as potential therapeutics in disorders in which EphA4-mediated signaling plays a role.
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Affiliation(s)
- Lies Schoonaert
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Laura Rué
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Bart Roucourt
- KU Leuven-University of Leuven, Laboratory for Signal Integration in Cell Fate Decision, 3000 Leuven, Belgium
| | - Mieke Timmers
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Susan Little
- Vertex Pharmaceuticals (Europe) Ltd., Biology Department, OX14 4RW Abingdon, United Kingdom
| | - Lucía Chávez-Gutiérrez
- VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium.,KU Leuven, Department of Neurosciences and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium
| | - Maarten Dewilde
- VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium.,KU Leuven, Department of Neurosciences and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium
| | - Peter Joyce
- Vertex Pharmaceuticals (Europe) Ltd., Biology Department, OX14 4RW Abingdon, United Kingdom
| | - Adam Curnock
- Vertex Pharmaceuticals (Europe) Ltd., Biology Department, OX14 4RW Abingdon, United Kingdom
| | - Peter Weber
- Vertex Pharmaceuticals (Europe) Ltd., Biology Department, OX14 4RW Abingdon, United Kingdom
| | - Jurgen Haustraete
- Protein Service Facility, Inflammation Research Center, VIB, Ghent University, 9052 Ghent, Belgium
| | | | - Bart De Strooper
- VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium.,KU Leuven, Department of Neurosciences and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,Institute of Neurology, University College London, WC1E 6BT London, United Kingdom, and
| | - Ludo Van Den Bosch
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Philip Van Damme
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium.,University Hospitals Leuven, Department of Neurology, 3000 Leuven, Belgium
| | - Robin Lemmens
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium.,VIB, Center for Brain and Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium.,University Hospitals Leuven, Department of Neurology, 3000 Leuven, Belgium
| | - Wim Robberecht
- From the KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Research Institute for Neuroscience and Disease (LIND), 3000 Leuven, Belgium, .,University Hospitals Leuven, Department of Neurology, 3000 Leuven, Belgium
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24
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Wu B, De SK, Kulinich A, Salem AF, Koeppen J, Wang R, Barile E, Wang S, Zhang D, Ethell I, Pellecchia M. Potent and Selective EphA4 Agonists for the Treatment of ALS. Cell Chem Biol 2017; 24:293-305. [PMID: 28196613 DOI: 10.1016/j.chembiol.2017.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/16/2016] [Accepted: 01/19/2017] [Indexed: 12/16/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease that affects motor neurons. Recent studies identified the receptor tyrosine kinase EphA4 as a disease-modifying gene that is critical for the progression of motor neuron degeneration. We report on the design and characterization of a family of EphA4 targeting agents that bind to its ligand binding domain with nanomolar affinity. The molecules exhibit excellent selectivity and display efficacy in a SOD1 mutant mouse model of ALS. Interestingly, the molecules appear to act as agonists for the receptor in certain surrogate cellular assays. While the exact mechanisms responsible for the therapeutic effect of the new agonists remain to be elucidated, we believe that the described agent represents both an invaluable pharmacological tool to further decipher the role of the EphA4 in ALS and potentially other human diseases, and a significant stepping stone for the development of novel treatments.
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Affiliation(s)
- Bainan Wu
- Sanford-Burnham-Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Surya K De
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Anna Kulinich
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Ahmed F Salem
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Jordan Koeppen
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Rengang Wang
- Sanford-Burnham-Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA; Brain Development, University of California San Diego, San Diego, CA 92090, USA
| | - Elisa Barile
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Si Wang
- Sanford-Burnham-Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Dongxiang Zhang
- Sanford-Burnham-Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Iryna Ethell
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Maurizio Pellecchia
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, 900 University Avenue, Riverside, CA 92521, USA.
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25
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Pleiss MM, Sompol P, Kraner SD, Abdul HM, Furman JL, Guttmann RP, Wilcock DM, Nelson PT, Norris CM. Calcineurin proteolysis in astrocytes: Implications for impaired synaptic function. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1521-32. [PMID: 27212416 DOI: 10.1016/j.bbadis.2016.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 05/14/2016] [Accepted: 05/16/2016] [Indexed: 01/01/2023]
Abstract
Mounting evidence suggests that astrocyte activation, found in most forms of neural injury and disease, is linked to the hyperactivation of the protein phosphatase calcineurin. In many tissues and cell types, calcineurin hyperactivity is the direct result of limited proteolysis. However, little is known about the proteolytic status of calcineurin in activated astrocytes. Here, we developed a polyclonal antibody to a high activity calcineurin proteolytic fragment in the 45-48kDa range (ΔCN) for use in immunohistochemical applications. When applied to postmortem human brain sections, the ΔCN antibody intensely labeled cell clusters in close juxtaposition to amyloid deposits and microinfarcts. Many of these cells exhibited clear activated astrocyte morphology. The expression of ΔCN in astrocytes near areas of pathology was further confirmed using confocal microscopy. Multiple NeuN-positive cells, particularly those within microinfarct core regions, also labeled positively for ΔCN. This observation suggests that calcineurin proteolysis can also occur within damaged or dying neurons, as reported in other studies. When a similar ΔCN fragment was selectively expressed in hippocampal astrocytes of intact rats (using adeno-associated virus), we observed a significant reduction in the strength of CA3-CA1 excitatory synapses, indicating that the hyperactivation of astrocytic calcineurin is sufficient for disrupting synaptic function. Together, these results suggest that proteolytic activation of calcineurin in activated astrocytes may be a central mechanism for driving and/or exacerbating neural dysfunction during neurodegenerative disease and injury.
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Affiliation(s)
- Melanie M Pleiss
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Pradoldej Sompol
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Susan D Kraner
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Hafiz Mohmmad Abdul
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Jennifer L Furman
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Rodney P Guttmann
- Department of Psychology, University of West Florida, Pensacola, FL, USA.
| | - Donna M Wilcock
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Peter T Nelson
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Pathology and Laboratory Medicine, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Christopher M Norris
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA; Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
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26
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Ablation of Type-1 IFN Signaling in Hematopoietic Cells Confers Protection Following Traumatic Brain Injury. eNeuro 2016; 3:eN-NWR-0128-15. [PMID: 27022620 PMCID: PMC4757777 DOI: 10.1523/eneuro.0128-15.2016] [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: 10/28/2015] [Revised: 12/21/2015] [Accepted: 01/14/2016] [Indexed: 12/31/2022] Open
Abstract
Type-1 interferons (IFNs) are pleiotropic cytokines that signal through the type-1 IFN receptor (IFNAR1). Recent literature has implicated the type-1 IFNs in disorders of the CNS. In this study, we have investigated the role of type-1 IFNs in neuroinflammation following traumatic brain injury (TBI). Using a controlled cortical impact model, TBI was induced in 8- to 10-week-old male C57BL/6J WT and IFNAR1−/− mice and brains were excised to study infarct volume, inflammatory mediator release via quantitative PCR analysis and immune cell profile via immunohistochemistry. IFNAR1−/− mice displayed smaller infarcts compared with WT mice after TBI. IFNAR1−/− mice exhibited an altered anti-inflammatory environment compared with WT mice, with significantly reduced levels of the proinflammatory mediators TNFα, IL-1β and IL-6, an up-regulation of the anti-inflammatory mediator IL-10 and an increased activation of resident and peripheral immune cells after TBI. WT mice injected intravenously with an anti-IFNAR1 blocking monoclonal antibody (MAR1) 1 h before, 30 min after or 30 min and 2 d after TBI displayed significantly improved histological and behavioral outcome. Bone marrow chimeras demonstrated that the hematopoietic cells are a peripheral source of type-1 IFNs that drives neuroinflammation and a worsened TBI outcome. Type-1 IFN mRNA levels were confirmed to be significantly altered in human postmortem TBI brains. Together, these data demonstrate that type-1 IFN signaling is a critical pathway in the progression of neuroinflammation and presents a viable therapeutic target for the treatment of TBI.
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27
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Yan EB, Frugier T, Lim CK, Heng B, Sundaram G, Tan M, Rosenfeld JV, Walker DW, Guillemin GJ, Morganti-Kossmann MC. Activation of the kynurenine pathway and increased production of the excitotoxin quinolinic acid following traumatic brain injury in humans. J Neuroinflammation 2015; 12:110. [PMID: 26025142 PMCID: PMC4457980 DOI: 10.1186/s12974-015-0328-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 05/20/2015] [Indexed: 12/14/2022] Open
Abstract
Abstract During inflammation, the kynurenine pathway (KP) metabolises the essential amino acid tryptophan (TRP) potentially contributing to excitotoxicity via the release of quinolinic acid (QUIN) and 3-hydroxykynurenine (3HK). Despite the importance of excitotoxicity in the development of secondary brain damage, investigations on the KP in TBI are scarce. In this study, we comprehensively characterised changes in KP activation by measuring numerous metabolites in cerebrospinal fluid (CSF) from TBI patients and assessing the expression of key KP enzymes in brain tissue from TBI victims. Acute QUIN levels were further correlated with outcome scores to explore its prognostic value in TBI recovery. Methods Twenty-eight patients with severe TBI (GCS ≤ 8, three patients had initial GCS = 9–10, but rapidly deteriorated to ≤8) were recruited. CSF was collected from admission to day 5 post-injury. TRP, kynurenine (KYN), kynurenic acid (KYNA), QUIN, anthranilic acid (AA) and 3-hydroxyanthranilic acid (3HAA) were measured in CSF. The Glasgow Outcome Scale Extended (GOSE) score was assessed at 6 months post-TBI. Post-mortem brains were obtained from the Australian Neurotrauma Tissue and Fluid Bank and used in qPCR for quantitating expression of KP enzymes (indoleamine 2,3-dioxygenase-1 (IDO1), kynurenase (KYNase), kynurenine amino transferase-II (KAT-II), kynurenine 3-monooxygenase (KMO), 3-hydroxyanthranilic acid oxygenase (3HAO) and quinolinic acid phosphoribosyl transferase (QPRTase) and IDO1 immunohistochemistry. Results In CSF, KYN, KYNA and QUIN were elevated whereas TRP, AA and 3HAA remained unchanged. The ratios of QUIN:KYN, QUIN:KYNA, KYNA:KYN and 3HAA:AA revealed that QUIN levels were significantly higher than KYN and KYNA, supporting increased neurotoxicity. Amplified IDO1 and KYNase mRNA expression was demonstrated on post-mortem brains, and enhanced IDO1 protein coincided with overt tissue damage. QUIN levels in CSF were significantly higher in patients with unfavourable outcome and inversely correlated with GOSE scores. Conclusion TBI induced a striking activation of the KP pathway with sustained increase of QUIN. The exceeding production of QUIN together with increased IDO1 activation and mRNA expression in brain-injured areas suggests that TBI selectively induces a robust stimulation of the neurotoxic branch of the KP pathway. QUIN’s detrimental roles are supported by its association to adverse outcome potentially becoming an early prognostic factor post-TBI.
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Affiliation(s)
- Edwin B Yan
- Department of Physiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Tony Frugier
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia
| | - Chai K Lim
- Neuroinflammation group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Benjamin Heng
- Neuroinflammation group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Gayathri Sundaram
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia
| | - May Tan
- Hospital Queen Elizabeth, Karung Berkunci No. 2029, 88586, Kota Kinabalu, Sabah, Malaysia
| | - Jeffrey V Rosenfeld
- Department of Neurosurgery, The Alfred Hospital, Melbourne, Australia.,Department of Surgery, Central Clinical School and Monash Institute of Medical Engineering, Monash University, Melbourne, Australia
| | - David W Walker
- The Ritchie Centre, Hudson Institute of Medical Research, Monash Medical Centre, Melbourne, Australia
| | - Gilles J Guillemin
- Neuroinflammation group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Maria Cristina Morganti-Kossmann
- Australian New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.,Department of Child Health, Barrow Neurological Institute, University of Arizona, Phoenix, AZ, USA
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28
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Abstract
Eph receptor tyrosine kinases and the corresponding ephrin ligands play a pivotal role in the glioma development and progression. Aberrant protein expression levels of the Eph receptors and ephrins are often associated with higher tumor grade and poor prognosis. Their function in tumorigenesis is complex due to the intricate network of possible co-occurring interactions between neighboring tumor cells and tumor microenvironment. Both Ephs and ephrins localize on the surface of tumor cells, tumor vasculature, glioma stem cells, tumor cells infiltrating brain, and immune cells infiltrating tumors. They can both promote and inhibit tumorigenicity depending on the downstream forward and reverse signalling generated. All the above-mentioned features make the Ephs/ephrins system an intriguing candidate for the development of new therapeutic strategies in glioma treatment. This review will give a general overview on the structure and the function of Ephs and ephrins, with a particular emphasis on the state of the knowledge of their role in malignant gliomas.
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Affiliation(s)
- Sara Ferluga
- Department of Neurosurgery, Brain Tumor Center of Excellence, Comprehensive Cancer Center of Wake Forest University, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Waldemar Debinski
- Department of Neurosurgery, Brain Tumor Center of Excellence, Comprehensive Cancer Center of Wake Forest University, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
- To whom correspondence should be addressed: Waldemar Debinski, M.D., Ph.D., Director of Brain Tumor Center of Excellence, Thomas K. Hearn Jr. Brain Tumor Research Center, Professor of Neurosurgery, Radiation Oncology, and Cancer Biology, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC 27157, Phone: (336) 716-9712, Fax: (336) 713-7639,
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29
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Identification of serum microRNA signatures for diagnosis of mild traumatic brain injury in a closed head injury model. PLoS One 2014; 9:e112019. [PMID: 25379886 PMCID: PMC4224512 DOI: 10.1371/journal.pone.0112019] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/27/2014] [Indexed: 01/15/2023] Open
Abstract
Wars in Iraq and Afghanistan have highlighted the problems of diagnosis and treatment of mild traumatic brain injury (mTBI). MTBI is a heterogeneous injury that may lead to the development of neurological and behavioral disorders. In the absence of specific diagnostic markers, mTBI is often unnoticed or misdiagnosed. In this study, mice were induced with increasing levels of mTBI and microRNA (miRNA) changes in the serum were determined. MTBI was induced by varying weight and fall height of the impactor rod resulting in four different severity grades of the mTBI. Injuries were characterized as mild by assessing with the neurobehavioral severity scale-revised (NSS-R) at day 1 post injury. Open field locomotion and acoustic startle response showed behavioral and sensory motor deficits in 3 of the 4 injury groups at day 1 post injury. All of the animals recovered after day 1 with no significant neurobehavioral alteration by day 30 post injury. Serum microRNA (miRNA) profiles clearly differentiated injured from uninjured animals. Overall, the number of miRNAs that were significantly modulated in injured animals over the sham controls increased with the severity of the injury. Thirteen miRNAs were found to identify mTBI regardless of its severity within the mild spectrum of injury. Bioinformatics analyses revealed that the more severe brain injuries were associated with a greater number of miRNAs involved in brain related functions. The evaluation of serum miRNA may help to identify the severity of brain injury and the risk of developing adverse effects after TBI.
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30
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Heinzelmann M, Reddy SY, French LM, Wang D, Lee H, Barr T, Baxter T, Mysliwiec V, Gill J. Military personnel with chronic symptoms following blast traumatic brain injury have differential expression of neuronal recovery and epidermal growth factor receptor genes. Front Neurol 2014; 5:198. [PMID: 25346719 PMCID: PMC4191187 DOI: 10.3389/fneur.2014.00198] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/18/2014] [Indexed: 01/23/2023] Open
Abstract
Objective: Approximately one-quarter of military personnel who deployed to combat stations sustained one or more blast-related, closed-head injuries. Blast injuries result from the detonation of an explosive device. The mechanisms associated with blast exposure that give rise to traumatic brain injury (TBI), and place military personnel at high risk for chronic symptoms of post-concussive disorder (PCD), post-traumatic stress disorder (PTSD), and depression are not elucidated. Methods: To investigate the mechanisms of persistent blast-related symptoms, we examined expression profiles of transcripts across the genome to determine the role of gene activity in chronic symptoms following blast-TBI. Active duty military personnel with (1) a medical record of a blast-TBI that occurred during deployment (n = 19) were compared to control participants without TBI (n = 17). Controls were matched to cases on demographic factors including age, gender, and race, and also in diagnoses of sleep disturbance, and symptoms of PTSD and depression. Due to the high number of PCD symptoms in the TBI+ group, we did not match on this variable. Using expression profiles of transcripts in microarray platform in peripheral samples of whole blood, significantly differentially expressed gene lists were generated. Statistical threshold is based on criteria of 1.5 magnitude fold-change (up or down) and p-values with multiple test correction (false discovery rate <0.05). Results: There were 34 transcripts in 29 genes that were differentially regulated in blast-TBI participants compared to controls. Up-regulated genes included epithelial cell transforming sequence and zinc finger proteins, which are necessary for astrocyte differentiation following injury. Tensin-1, which has been implicated in neuronal recovery in pre-clinical TBI models, was down-regulated in blast-TBI participants. Protein ubiquitination genes, such as epidermal growth factor receptor, were also down-regulated and identified as the central regulators in the gene network determined by interaction pathway analysis. Conclusion: In this study, we identified a gene-expression pathway of delayed neuronal recovery in military personnel a blast-TBI and chronic symptoms. Future work is needed to determine if therapeutic agents that regulate these pathways may provide novel treatments for chronic blast-TBI-related symptoms.
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Affiliation(s)
- Morgan Heinzelmann
- National Institute of Nursing Research, National Institutes of Health , Bethesda, MD , USA
| | - Swarnalatha Y Reddy
- National Institute of Nursing Research, National Institutes of Health , Bethesda, MD , USA
| | - Louis M French
- Center for Neuroscience and Regenerative Medicine , Bethesda, MD , USA ; Defense and Veterans Brain Injury Center, Walter Reed National Military Medical Center , Bethesda, MD , USA
| | - Dan Wang
- National Institute of Nursing Research, National Institutes of Health , Bethesda, MD , USA
| | - Hyunhwa Lee
- National Institute of Nursing Research, National Institutes of Health , Bethesda, MD , USA
| | - Taura Barr
- West Virginia University Health Sciences Center , Morgantown, WV , USA
| | - Tristin Baxter
- Sleep Medicine Clinic, Madigan Army Medical Center , Tacoma, WA , USA
| | - Vincent Mysliwiec
- Sleep Medicine Clinic, Madigan Army Medical Center , Tacoma, WA , USA
| | - Jessica Gill
- National Institute of Nursing Research, National Institutes of Health , Bethesda, MD , USA
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Ayton S, Zhang M, Roberts BR, Lam LQ, Lind M, McLean C, Bush AI, Frugier T, Crack PJ, Duce JA. Ceruloplasmin and β-amyloid precursor protein confer neuroprotection in traumatic brain injury and lower neuronal iron. Free Radic Biol Med 2014; 69:331-7. [PMID: 24509156 DOI: 10.1016/j.freeradbiomed.2014.01.041] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/10/2014] [Accepted: 01/31/2014] [Indexed: 10/25/2022]
Abstract
Traumatic brain injury (TBI) is in part complicated by pro-oxidant iron elevation independent of brain hemorrhage. Ceruloplasmin (CP) and β-amyloid protein precursor (APP) are known neuroprotective proteins that reduce oxidative damage through iron regulation. We surveyed iron, CP, and APP in brain tissue from control and TBI-affected patients who were stratified according to time of death following injury. We observed CP and APP induction after TBI accompanying iron accumulation. Elevated APP and CP expression was also observed in a mouse model of focal cortical contusion injury concomitant with iron elevation. To determine if changes in APP or CP were neuroprotective we employed the same TBI model on APP(-/-) and CP(-/-) mice and found that both exhibited exaggerated infarct volume and iron accumulation postinjury. Evidence supports a regulatory role of both proteins in defence against iron-induced oxidative damage after TBI, which presents as a tractable therapeutic target.
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Affiliation(s)
- Scott Ayton
- Oxidation Biology Unit, The Florey Institute of Neuroscience and Mental Health
| | - Moses Zhang
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Blaine R Roberts
- Oxidation Biology Unit, The Florey Institute of Neuroscience and Mental Health
| | - Linh Q Lam
- Oxidation Biology Unit, The Florey Institute of Neuroscience and Mental Health
| | - Monica Lind
- Oxidation Biology Unit, The Florey Institute of Neuroscience and Mental Health
| | - Catriona McLean
- Department of Pathology, and The University of Melbourne, Parkville, VIC 3010, Australia
| | - Ashley I Bush
- Oxidation Biology Unit, The Florey Institute of Neuroscience and Mental Health; Department of Pathology, and The University of Melbourne, Parkville, VIC 3010, Australia
| | - Tony Frugier
- Department of Anatomy and Cell Biology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Peter J Crack
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC 3010, Australia
| | - James A Duce
- Oxidation Biology Unit, The Florey Institute of Neuroscience and Mental Health; School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, North Yorkshire, UK.
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Goldshmit Y, Homman-Ludiye J, Bourne JA. EphA4 is associated with multiple cell types in the marmoset primary visual cortex throughout the lifespan. Eur J Neurosci 2014; 39:1419-28. [DOI: 10.1111/ejn.12514] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/01/2014] [Accepted: 01/14/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Yona Goldshmit
- Australian Regenerative Medicine Institute; Monash University; Building 75 Clayton Vic. 3800 Australia
| | - Jihane Homman-Ludiye
- Australian Regenerative Medicine Institute; Monash University; Building 75 Clayton Vic. 3800 Australia
| | - James A. Bourne
- Australian Regenerative Medicine Institute; Monash University; Building 75 Clayton Vic. 3800 Australia
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Park K, Biederer T. Neuronal adhesion and synapse organization in recovery after brain injury. FUTURE NEUROLOGY 2013; 8:555-567. [PMID: 24489481 DOI: 10.2217/fnl.13.35] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Few specific therapeutic targets exist to manage brain injury, despite the prevalence of stroke or traumatic brain injury. With traumatic brain injury, characteristic neuronal changes include axonal swelling and degeneration, and the loss of synapses, the sites of communication between neurons. This is followed by axonal sprouting and alterations in synaptic markers in recovery. The resulting changes in neuronal connectivity are likely to contribute to the effects of traumatic brain injury on cognitive functions and the underlying mechanisms may represent points of therapeutic intervention. In agreement, animal studies implicate adhesion and signaling molecules that organize synapses as molecular players in neuronal recovery. In this article, the authors focus on the role of cell surface interactions in the recovery after brain injury in humans and animals. The authors review cellular and synaptic alterations that occur with injury and how changes in cell adhesion, protein expression and modification may be involved in recovery. The changes in neuronal surface interactions as potential targets and their possible value for the development of therapeutics are also discussed.
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Affiliation(s)
- Kellie Park
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA
| | - Thomas Biederer
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, CT, USA ; Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT, USA
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Tadesse T, Cheng Q, Xu M, Baro DJ, Young LJ, Pallas SL. Regulation of ephrin-A expression in compressed retinocollicular maps. Dev Neurobiol 2012; 73:274-96. [PMID: 23008269 DOI: 10.1002/dneu.22059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 09/14/2012] [Accepted: 09/18/2012] [Indexed: 11/11/2022]
Abstract
Retinotopic maps can undergo compression and expansion in response to changes in target size, but the mechanism underlying this compensatory process has remained a mystery. The discovery of ephrins as molecular mediators of Sperry's chemoaffinity process allows a mechanistic approach to this important issue. In Syrian hamsters, neonatal, partial (PT) ablation of posterior superior colliculus (SC) leads to compression of the retinotopic map, independent of neural activity. Graded, repulsive EphA receptor/ephrin-A ligand interactions direct the formation of the retinocollicular map, but whether ephrins might also be involved in map compression is unknown. To examine whether map compression might be directed by changes in the ephrin expression pattern, we compared ephrin-A2 and ephrin-A5 mRNA expression between normal SC and PT SC using in situ hybridization and quantitative real-time PCR. We found that ephrin-A ligand expression in the compressed maps was low anteriorly and high posteriorly, as in normal animals. Consistent with our hypothesis, the steepness of the ephrin gradient increased in the lesioned colliculi. Interestingly, overall levels of ephrin-A2 and -A5 expression declined immediately after neonatal target damage, perhaps promoting axon outgrowth. These data establish a correlation between changes in ephrin-A gradients and map compression, and suggest that ephrin-A expression gradients may be regulated by target size. This in turn could lead to compression of the retinocollicular map onto the reduced target. These findings have important implications for mechanisms of recovery from traumatic brain injury.
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Affiliation(s)
- Tizeta Tadesse
- Neuroscience Institute, Department of Biology, Graduate Program in Neurobiology & Behavior, Georgia State University, Atlanta, Georgia, USA
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Hånell A, Clausen F, Djupsjö A, Vallstedt A, Patra K, Israelsson C, Larhammar M, Björk M, Paixão S, Kullander K, Marklund N. Functional and Histological Outcome after Focal Traumatic Brain Injury Is Not Improved in Conditional EphA4 Knockout Mice. J Neurotrauma 2012; 29:2660-71. [DOI: 10.1089/neu.2012.2376] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Anders Hånell
- Section for Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Fredrik Clausen
- Section for Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Anders Djupsjö
- Section for Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Anna Vallstedt
- Section for Developmental Genetics, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Kalicharan Patra
- Section for Developmental Genetics, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Charlotte Israelsson
- Section for Developmental Neuroscience, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Martin Larhammar
- Section for Developmental Genetics, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Maria Björk
- Section for Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Sónia Paixão
- Department of Molecular Neurobiology, Max-Planck Institute of Neurobiology, Martinsried, Germany
| | - Klas Kullander
- Section for Developmental Genetics, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- Section for Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden
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Coulthard MG, Morgan M, Woodruff TM, Arumugam TV, Taylor SM, Carpenter TC, Lackmann M, Boyd AW. Eph/Ephrin signaling in injury and inflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1493-503. [PMID: 23021982 DOI: 10.1016/j.ajpath.2012.06.043] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 06/28/2012] [Indexed: 12/20/2022]
Abstract
The Eph/ephrin receptor-ligand system plays an important role in embryogenesis and adult life, principally by influencing cell behavior through signaling pathways, resulting in modification of the cell cytoskeleton and cell adhesion. There are 10 EphA receptors, and six EphB receptors, distinguished on sequence difference and binding preferences, that interact with the six glycosylphosphatidylinositol-linked ephrin-A ligands and the three transmembrane ephrin-B ligands, respectively. The Eph/ephrin proteins, originally described as developmental regulators that are expressed at low levels postembryonically, are re-expressed after injury to the optic nerve, spinal cord, and brain in fish, amphibians, rodents, and humans. In rodent spinal cord injury, the up-regulation of EphA4 prevents recovery by inhibiting axons from crossing the injury site. Eph/ephrin proteins may be partly responsible for the phenotypic changes to the vascular endothelium in inflammation, which allows fluid and inflammatory cells to pass from the vascular space into the interstitial tissues. Specifically, EphA2/ephrin-A1 signaling in the lung may be responsible for pulmonary inflammation in acute lung injury. A role in T-cell maturation and chronic inflammation (heart failure, inflammatory bowel disease, and rheumatoid arthritis) is also reported. Although there remains much to learn about Eph/ephrin signaling in human disease, and specifically in injury and inflammation, this area of research raises the exciting prospect that novel therapies will be developed that precisely target these pathways.
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Affiliation(s)
- Mark G Coulthard
- Academic Discipline of Paediatrics and Child Health, University of Queensland, Royal Children's Hospital, Herston, Australia.
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Albert-Weissenberger C, Stetter C, Meuth SG, Göbel K, Bader M, Sirén AL, Kleinschnitz C. Blocking of bradykinin receptor B1 protects from focal closed head injury in mice by reducing axonal damage and astroglia activation. J Cereb Blood Flow Metab 2012; 32:1747-56. [PMID: 22569191 PMCID: PMC3434625 DOI: 10.1038/jcbfm.2012.62] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The two bradykinin receptors B1R and B2R are central components of the kallikrein-kinin system with different expression kinetics and binding characteristics. Activation of these receptors by kinins triggers inflammatory responses in the target organ and in most situations enhances tissue damage. We could recently show that blocking of B1R, but not B2R, protects from cortical cryolesion by reducing inflammation and edema formation. In the present study, we investigated the role of B1R and B2R in a closed head model of focal traumatic brain injury (TBI; weight drop). Increased expression of B1R in the injured hemispheres of wild-type mice was restricted to the later stages after brain trauma, i.e. day 7 (P<0.05), whereas no significant induction could be observed for the B2R (P>0.05). Mice lacking the B1R, but not the B2R, showed less functional deficits on day 3 (P<0.001) and day 7 (P<0.001) compared with controls. Pharmacological blocking of B1R in wild-type mice had similar effects. Reduced axonal injury and astroglia activation could be identified as underlying mechanisms, while inhibition of B1R had only little influence on the local inflammatory response in this model. Inhibition of B1R may become a novel strategy to counteract trauma-induced neurodegeneration.
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