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Hall BE, Macdonald E, Cassidy M, Yun S, Sapio MR, Ray P, Doty M, Nara P, Burton MD, Shiers S, Ray-Chaudhury A, Mannes AJ, Price TJ, Iadarola MJ, Kulkarni AB. Transcriptomic analysis of human sensory neurons in painful diabetic neuropathy reveals inflammation and neuronal loss. Sci Rep 2022; 12:4729. [PMID: 35304484 PMCID: PMC8933403 DOI: 10.1038/s41598-022-08100-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 02/25/2022] [Indexed: 01/02/2023] Open
Abstract
Pathological sensations caused by peripheral painful neuropathy occurring in Type 2 diabetes mellitus (T2DM) are often described as 'sharp' and 'burning' and are commonly spontaneous in origin. Proposed etiologies implicate dysfunction of nociceptive sensory neurons in dorsal root ganglia (DRG) induced by generation of reactive oxygen species, microvascular defects, and ongoing axonal degeneration and regeneration. To investigate the molecular mechanisms contributing to diabetic pain, DRGs were acquired postmortem from patients who had been experiencing painful diabetic peripheral neuropathy (DPN) and subjected to transcriptome analyses to identify genes contributing to pathological processes and neuropathic pain. DPN occurs in distal extremities resulting in the characteristic "glove and stocking" pattern. Accordingly, the L4 and L5 DRGs, which contain the perikarya of primary afferent neurons innervating the foot, were analyzed from five DPN patients and compared with seven controls. Transcriptome analyses identified 844 differentially expressed genes. We observed increases in levels of inflammation-associated transcripts from macrophages in DPN patients that may contribute to pain hypersensitivity and, conversely, there were frequent decreases in neuronally-related genes. The elevated inflammatory gene profile and the accompanying downregulation of multiple neuronal genes provide new insights into intraganglionic pathology and mechanisms causing neuropathic pain in DPN patients with T2DM.
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Affiliation(s)
- Bradford E Hall
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 130, Bethesda, MD, 20892, USA
| | - Emma Macdonald
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 130, Bethesda, MD, 20892, USA
- Present Affiliation: NIH Graduate Partnerships Program, Brown University, Providence, RI, 02912, USA
| | - Margaret Cassidy
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 130, Bethesda, MD, 20892, USA
| | - Sijung Yun
- Yotta Biomed, LLC, Bethesda, MD, 20814, USA
| | - Matthew R Sapio
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Pradipta Ray
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Megan Doty
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 130, Bethesda, MD, 20892, USA
| | - Pranavi Nara
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Michael D Burton
- Neuroimmunology and Behavior Group, School of Behavior and Brain Sciences, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Stephanie Shiers
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Abhik Ray-Chaudhury
- Surgical Neurology Branch, Disorders and Stroke, National Institute of Neurological, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Andrew J Mannes
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Theodore J Price
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ashok B Kulkarni
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 130, Bethesda, MD, 20892, USA.
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2
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Protective Mechanism and Treatment of Neurogenesis in Cerebral Ischemia. Neurochem Res 2020; 45:2258-2277. [PMID: 32794152 DOI: 10.1007/s11064-020-03092-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/18/2020] [Accepted: 07/08/2020] [Indexed: 12/14/2022]
Abstract
Stroke is the fifth leading cause of death worldwide and is a main cause of disability in adults. Neither currently marketed drugs nor commonly used treatments can promote nerve repair and neurogenesis after stroke, and the repair of neurons damaged by ischemia has become a research focus. This article reviews several possible mechanisms of stroke and neurogenesis and introduces novel neurogenic agents (fibroblast growth factors, brain-derived neurotrophic factor, purine nucleosides, resveratrol, S-nitrosoglutathione, osteopontin, etc.) as well as other treatments that have shown neuroprotective or neurogenesis-promoting effects.
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3
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Hoek JM, Hepkema WM, Halffman W. The effect of journal guidelines on the reporting of antibody validation. PeerJ 2020; 8:e9300. [PMID: 32547887 PMCID: PMC7275675 DOI: 10.7717/peerj.9300] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/14/2020] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Despite the widespread use of antibodies as a research tool, problems with specificity, lot-to-lot consistency and sensitivity commonly occur and may be important contributing factors to the 'replication crisis' in biomedical research. This makes the validation of antibodies and accurate reporting of this validation in the scientific literature extremely important. Therefore, some journals now require authors to comply with antibody reporting guidelines. METHODS We used a quasi-experimental approach to assess the effectiveness of such journal guidelines in improving antibody reporting in the scientific literature. In a sample of 120 publications, we compared the reporting of antibody validation and identification information in two journals with guidelines (Nature and the Journal of Comparative Neurology) with two journals without guidelines (Science and Neuroscience), before and after the introduction of these guidelines. RESULTS Our results suggest that the implementation of antibody reporting guidelines might have some influence on the reporting of antibody validation information. The percentage of validated antibodies per article slightly increased from 39% to 57% in journals with guidelines, whereas this percentage decreased from 23% to 14% in journals without guidelines. Furthermore, the reporting of validation information of all primary antibodies increased by 23 percentage points in the journals with guidelines (OR = 2.80, 95% CI = 0.96-INF; adjusted p = 1, one-tailed), compared to a decrease of 13 percentage points in journals without guidelines. Fortunately, the guidelines seem to be more effective in improving the reporting of antibody identification information. The reporting of identification information of all primary antibodies used in a study increased by 58 percentage points (OR = 17.8, 95% CI = 4.8-INF; adjusted p = 0.0003, one-tailed) in journals with guidelines. This percentage also slightly increased in journals without guidelines (by 18 percentage points), suggesting an overall increased awareness of the importance of antibody identifiability. Moreover, this suggests that reporting guidelines mostly have an influence on the reporting of information that is relatively easy to provide. A small increase in the reporting of validation by referencing the scientific literature or the manufacturer's data also indicates this. CONCLUSION Combined with the results of previous studies on journal guidelines, our study suggests that the effect of journal antibody guidelines on validation practices by themselves may be limited, since they mostly seem to improve antibody identification instead of actual experimental validation. These guidelines, therefore, may require additional measures to ensure effective implementation. However, due to the explorative nature of our study and our small sample size, we must remain cautious towards other factors that might have played a role in the observed change in antibody reporting behaviour.
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Affiliation(s)
- Joyce M. Hoek
- Department of Psychology, University of Groningen, Groningen, The Netherlands
- Institute for Science in Society, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Wytske M. Hepkema
- Institute for Science in Society, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Willem Halffman
- Institute for Science in Society, Radboud University Nijmegen, Nijmegen, The Netherlands
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4
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Emerging Roles of Ephexins in Physiology and Disease. Cells 2019; 8:cells8020087. [PMID: 30682817 PMCID: PMC6406967 DOI: 10.3390/cells8020087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/20/2019] [Accepted: 01/24/2019] [Indexed: 12/25/2022] Open
Abstract
Dbl (B-cell lymphoma)-related guanine nucleotide exchange factors (GEFs), the largest family of GEFs, are directly responsible for the activation of Rho family GTPases and essential for a number of cellular events such as proliferation, differentiation and movement. The members of the Ephexin (Eph-interacting exchange protein) family, a subgroup of Dbl GEFs, initially were named for their interaction with Eph receptors and sequence homology with Ephexin1. Although the first Ephexin was identified about two decades ago, their functions in physiological and pathological contexts and regulatory mechanisms remained elusive until recently. Ephexins are now considered as GEFs that can activate Rho GTPases such as RhoA, Rac, Cdc42, and RhoG. Moreover, Ephexins have been shown to have pivotal roles in neural development, tumorigenesis, and efferocytosis. In this review, we discuss the known and proposed functions of Ephexins in physiological and pathological contexts, as well as their regulatory mechanisms.
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Colón JM, González PA, Cajigas Á, Maldonado WI, Torrado AI, Santiago JM, Salgado IK, Miranda JD. Continuous tamoxifen delivery improves locomotor recovery 6h after spinal cord injury by neuronal and glial mechanisms in male rats. Exp Neurol 2018; 299:109-121. [PMID: 29037533 PMCID: PMC5723542 DOI: 10.1016/j.expneurol.2017.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/03/2017] [Accepted: 10/05/2017] [Indexed: 12/13/2022]
Abstract
No treatment is available for patients with spinal cord injury (SCI). Patients often arrive to the hospital hours after SCI suggesting the need of a therapy that can be used on a clinically relevant window. Previous studies showed that Tamoxifen (TAM) treatment 24h after SCI benefits locomotor recovery in female rats. Tamoxifen exerts beneficial effects in male and female rodents but a gap of knowledge exists on: the therapeutic window of TAM, the spatio-temporal mechanisms activated and if this response is sexually dimorphic. We hypothesized that TAM will favor locomotor recovery when administered up-to 24h after SCI in male Sprague-Dawley rats. Rats received a thoracic (T10) contusion using the MACSIS impactor followed by placebo or TAM (15mg/21days) pellets in a therapeutic window of 0, 6, 12, or 24h. Animals were sacrificed at 2, 7, 14, 28 or 35days post injury (DPI) to study the molecular and cellular changes in the acute and chronic stages. Immediate or delayed therapy (t=6h) improved locomotor function, increased white matter spared tissue, and neuronal survival. TAM reduced reactive gliosis during chronic stages and increased the expression of Olig-2. A significant difference was observed in estrogen receptor alpha between male and female rodents from 2 to 28 DPI suggesting a sexually dimorphic characteristic that could be related to the behavioral differences observed in the therapeutic window of TAM. This study supports the use of TAM in the SCI setting due to its neuroprotective effects but with a significant sexually dimorphic therapeutic window.
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Affiliation(s)
- Jennifer M Colón
- University of Puerto Rico Medical Sciences Campus, Department of Physiology, San Juan, PR 00936, USA.
| | - Pablo A González
- University of Puerto Rico Medical Sciences Campus, Department of Physiology, San Juan, PR 00936, USA.
| | - Ámbar Cajigas
- University of Puerto Rico Medical Sciences Campus, Department of Physiology, San Juan, PR 00936, USA.
| | - Wanda I Maldonado
- University of Puerto Rico Carolina Campus, Neuroregeneration Division, Neuroscience Research Laboratory, Natural Sciences Department, Carolina, PR 00984, USA.
| | - Aranza I Torrado
- University of Puerto Rico Medical Sciences Campus, Department of Physiology, San Juan, PR 00936, USA.
| | - José M Santiago
- University of Puerto Rico Carolina Campus, Neuroregeneration Division, Neuroscience Research Laboratory, Natural Sciences Department, Carolina, PR 00984, USA.
| | - Iris K Salgado
- University of Puerto Rico Medical Sciences Campus, Department of Physiology, San Juan, PR 00936, USA.
| | - Jorge D Miranda
- University of Puerto Rico Medical Sciences Campus, Department of Physiology, San Juan, PR 00936, USA.
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Fan R, Enkhjargal B, Camara R, Yan F, Gong L, ShengtaoYao, Tang J, Chen Y, Zhang JH. Critical role of EphA4 in early brain injury after subarachnoid hemorrhage in rat. Exp Neurol 2017; 296:41-48. [PMID: 28698029 DOI: 10.1016/j.expneurol.2017.07.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/07/2017] [Accepted: 07/07/2017] [Indexed: 01/31/2023]
Abstract
Early brain injury (EBI) is reported as a primary cause of mortality in subarachnoid hemorrhage (SAH) patients. Eph receptor A4 (EphA4) has been associated with blood-brain barrier integrity and pro-apoptosis. We aimed to investigate a role of EphA4 in EBI after SAH. One hundred and seventy-nine male adult Sprague-Dawley rats were randomly divided into sham versus endovascular perforation model of SAH groups. SAH grade, neurological score, Evans blue dye extravasation, brain water content, mortality, Fluoro-Jade staining, immunofluorescence staining, and western blot experiments were performed after SAH. Small interfering RNA (siRNA) for EphA4, recombinant Ephexin-1 (rEphx-1), and Fasudil, a potent ROCK2 inhibitor, were used for intervention to study a role of EphA4 on EBI after SAH. The expression of EphA4, Ephexin-1, RhoA, and ROCK2 significantly increased after SAH. Knockdown of EphA4 using EphA4 siRNA injection intracerebroventricularly (i.c.v) reduced Evans blue extravasation, decreased brain water content, and alleviated neurobehavioral dysfunction after SAH. Additionally, the expression of Ephexin-1, RhoA, ROCK2 and cleaved caspase-3 were decreased. Tight junction proteins increased, and apoptotic neuron death decreased. The effects of EphA4 siRNA were abolished by rEphx-1. In contrast, Fasudil abolished the effects of rEphx-1. These results suggest that EphA4, a novel and promising target for treatment, exacerbates EBI through an Ephexin-1/ROCK2 pathway after SAH.
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Affiliation(s)
- Ruiming Fan
- Department of Neurology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China; Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States
| | - Budbazar Enkhjargal
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States
| | - Richard Camara
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States
| | - Feng Yan
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States
| | - Lei Gong
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States
| | - ShengtaoYao
- Department of cerebrovascular, the Affiliated Hospital, Zunyi Medical University, Guizhou 563000, China
| | - Jiping Tang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States
| | - Yangmei Chen
- Department of Neurology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China.
| | - John H Zhang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States; Department of Anesthesiology, School of Medicine, Loma Linda University, Loma Linda, CA, 92354, United States; Department of Neurosurgery, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
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Vibulyaseck S, Fujita H, Luo Y, Tran AK, Oh-Nishi A, Ono Y, Hirano S, Sugihara I. Spatial rearrangement of Purkinje cell subsets forms the transverse and longitudinal compartmentalization in the mouse embryonic cerebellum. J Comp Neurol 2017; 525:2971-2990. [PMID: 28542916 DOI: 10.1002/cne.24250] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 11/08/2022]
Abstract
Transversely oriented lobules and longitudinally arrayed stripes of Purkinje cell subsets subdivide the cerebellar cortex into multiple compartments that are involved in diverse functions. In the mammalian cerebellum, anterior, and posterior lobules, which are involved in somatosensorimotor function, show an alternation of aldolase C (zebrin II) -positive and -negative stripes, whereas the central lobules (lobules VIb-VII and crus I), which are implicated in nonmotor functions, show a laterally expanded arrangement solely of aldolase C-positive stripes. To understand the developmental process of this compartmental pattern, we identified groups of Purkinje cell subsets in the entire mouse cerebellum at embryonic day (E) 14.5 by staining Purkinje cell subset markers. We then tracked four major domains of Protocadherin 10 (Pcdh10)-positive Purkinje cell subsets (medial, dorsal, central, and mid-lateral subsets), which were clearly demarcated during E14.5-17.5. These domains of Purkinje cell subsets shifted predominantly in the longitudinal direction to be positioned in the anterior and posterior lobules. However, a particular portion of the medial and mid-lateral domains, and the whole of the central domain shift in the lateral direction to be positioned in the central lobules. The results indicate that while the longitudinal shift of domains of Purkinje cell subsets forms the longitudinally striped compartments in the anterior and posterior cerebellum, the lateral shift of particular domains of Purkinje cell subsets underlies the laterally expanded arrangement of stripes in central lobules. Thus, the rearrangement of Purkinje cell subsets in the embryonic cerebellum is critically related to the compartmental organization in the mammalian cerebellum.
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Affiliation(s)
- Suteera Vibulyaseck
- Department of Systems Neurophysiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hirofumi Fujita
- Department of Systems Neurophysiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.,Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | - Yuanjun Luo
- Department of Systems Neurophysiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Anh Khoa Tran
- Department of Systems Neurophysiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Arata Oh-Nishi
- Department of Physics, Kitasato University, Sagamihara, Kanagawa, Japan.,RESVO Inc, Tokyo, Japan
| | - Yuichi Ono
- Department of Developmental Neurobiology, KAN Research Institute Inc, Kobe, Hyogo, Japan
| | - Shinji Hirano
- Department of Biology, Kansai Medical University, Hirakata-shi, Osaka-fu, Japan
| | - Izumi Sugihara
- Department of Systems Neurophysiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
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8
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Colón JM, Torrado AI, Cajigas Á, Santiago JM, Salgado IK, Arroyo Y, Miranda JD. Tamoxifen Administration Immediately or 24 Hours after Spinal Cord Injury Improves Locomotor Recovery and Reduces Secondary Damage in Female Rats. J Neurotrauma 2016; 33:1696-708. [PMID: 26896212 PMCID: PMC5035917 DOI: 10.1089/neu.2015.4111] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Spinal cord injury (SCI) is a condition with no available cure. The initial physical impact triggers a cascade of molecular and cellular events that generate a nonpermissive environment for cell survival and axonal regeneration. Spinal cord injured patients often arrive at the clinic hours after the initial insult. This indicates the need to study and develop treatments with a long therapeutic window of action and multiactive properties, which target the complex set of events that arise after the initial trauma. We provide evidence that tamoxifen (TAM), a drug approved by the Food and Drug Administration, exerts neuroprotective effects in an animal model when applied up-to 24 h after SCI. We hypothesized that continuous TAM administration will improve functional locomotor recovery by favoring myelin preservation and reducing secondary damage after SCI. Adult female Sprague-Dawley rats (∼230 g) received a moderate contusion to the thoracic (T9-T10) spinal cord, using the MASCIS impactor device. To determine the therapeutic window available for TAM treatment, rats were implanted with TAM pellets (15 mg) immediately or 24 h after SCI. Locomotor function (Basso, Beattie, Bresnahan open field test, grid walk, and beam crossing tests) was assessed weekly for 35 days post-injury. TAM-treated rats showed significant functional locomotor recovery and improved fine movements when treated immediately or 24 h after SCI. Further, TAM increased white matter preservation and reduced secondary damage caused by astrogliosis, axonal degeneration, and cell death after trauma. These results provide evidence for TAM as a potential therapeutic agent to treat SCI up to 24 h after the trauma.
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Affiliation(s)
- Jennifer M. Colón
- Department of Physiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Aranza I. Torrado
- Department of Physiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Ámbar Cajigas
- Department of Biology, University of Puerto Rico Rio Piedras Campus, San Juan, Puerto Rico
| | - José M. Santiago
- Department of Natural Sciences, University of Puerto Rico Carolina Campus, Carolina, Puerto Rico
| | - Iris K. Salgado
- Department of Physiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Yaría Arroyo
- Department of Natural Sciences, University of Puerto Rico Carolina Campus, Carolina, Puerto Rico
| | - Jorge D. Miranda
- Department of Physiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
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9
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Rosas OR, Torrado AI, Santiago JM, Rodriguez AE, Salgado IK, Miranda JD. Long-term treatment with PP2 after spinal cord injury resulted in functional locomotor recovery and increased spared tissue. Neural Regen Res 2015; 9:2164-73. [PMID: 25657738 PMCID: PMC4316450 DOI: 10.4103/1673-5374.147949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2014] [Indexed: 02/06/2023] Open
Abstract
The spinal cord has the ability to regenerate but the microenvironment generated after trauma reduces that capacity. An increase in Src family kinase (SFK) activity has been implicated in neuropathological conditions associated with central nervous system trauma. Therefore, we hypothesized that a decrease in SFK activation by a long-term treatment with 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyramidine (PP2), a selective SFK inhibitor, after spinal cord contusion with the New York University (NYU) impactor device would generate a permissive environment that improves axonal sprouting and/or behavioral activity. Results demonstrated that long-term blockade of SFK activation with PP2 increases locomotor activity at 7, 14, 21 and 28 days post-injury in the Basso, Beattie, and Bresnahan open field test, round and square beam crossing tests. In addition, an increase in white matter spared tissue and serotonin fiber density was observed in animals treated with PP2. However, blockade of SFK activity did not change the astrocytic response or infiltration of cells from the immune system at 28 days post-injury. Moreover, a reduced SFK activity with PP2 diminished Ephexin (a guanine nucleotide exchange factor) phosphorylation in the acute phase (4 days post-injury) after trauma. Together, these findings suggest a potential role of SFK in the regulation of spared tissue and/or axonal outgrowth that may result in functional locomotor recovery during the pathophysiology generated after spinal cord injury. Our study also points out that ephexin1 phosphorylation (activation) by SFK action may be involved in the repulsive microenvironment generated after spinal cord injury.
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Affiliation(s)
- Odrick R Rosas
- Department of Physiology, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA
| | - Aranza I Torrado
- Department of Physiology, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA
| | - Jose M Santiago
- Department of Natural Sciences, University of Puerto Rico Carolina Campus, Carolina, PR, USA
| | - Ana E Rodriguez
- Department of Physiology, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA
| | - Iris K Salgado
- Department of Physiology, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA
| | - Jorge D Miranda
- Department of Physiology, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA
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10
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Figueroa JD, Cordero K, Llán MS, De Leon M. Dietary omega-3 polyunsaturated fatty acids improve the neurolipidome and restore the DHA status while promoting functional recovery after experimental spinal cord injury. J Neurotrauma 2013; 30:853-68. [PMID: 23294084 DOI: 10.1089/neu.2012.2718] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) confer multiple health benefits and decrease the risk of neurological disorders. Studies are needed, however, to identify promising cellular targets and to assess their prophylactic value against neurodegeneration. The present study (1) examined the efficacy of a preventive diet enriched with ω-3 PUFAs to reduce dysfunction in a well-established spinal cord injury (SCI) animal model and (2) used a novel metabolomics data analysis to identify potential neurolipidomic targets. Rats were fed with either control chow or chow enriched with ω-3 PUFAs (750 mg/kg/day) for 8 weeks before being subjected to a sham or a contusion SCI operation. We report new evidence showing that rats subjected to SCI after being pre-treated with a diet enriched with ω-3 PUFAs exhibit significantly better functional outcomes. Pre-treated animals exhibited lower sensory deficits, autonomic bladder recovery, and early improvements in locomotion that persisted for at least 8 weeks after trauma. We found that SCI triggers a robust alteration in the cord PUFA neurolipidome, which was characterized by a marked docosahexaenoic acid (DHA) deficiency. This DHA deficiency was associated with dysfunction and corrected with the ω-3 PUFA-enriched diet. Multivariate data analyses revealed that the spinal cord of animals consuming the ω-3 PUFA-enriched diet had a fundamentally distinct neurolipidome, particularly increasing the levels of essential and long chain ω-3 fatty acids and lysolipids at the expense of ω-6 fatty acids and its metabolites. Altogether, dietary ω-3 PUFAs prophylaxis confers resiliency to SCI mediated, at least in part, by generating a neuroprotective and restorative neurolipidome.
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Affiliation(s)
- Johnny D Figueroa
- Center for Health Disparities and Molecular Medicine and Departments of Basic Sciences and Pathology and Human Anatomy, Loma Linda University, Loma Linda, California, USA
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11
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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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Hashimoto M, Ito R, Kitamura N, Namba K, Hisano Y. Epha4 controls the midline crossing and contralateral axonal projections of inferior olive neurons. J Comp Neurol 2012; 520:1702-20. [PMID: 22121026 DOI: 10.1002/cne.23008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The guidance of axonal projections to ipsilateral and contralateral regions is essential for integration of bilateral sensory information and coordination of movement. In the development of olivocerebellar projections, newborn neurons of inferior olivary (IO) nuclei ventrally migrate from the hindbrain rhombic lip to the floor plate (FP). The cell bodies of IO neurons cannot cross the FP but their axons can, and thus IO neurons project their axons only to the contralateral cerebellar cortex. The molecular mechanisms determining the contralateral axonal projections of IO neurons, however, are obscure. The IO neurons and their axons express EphA4, whereas the FP expresses an EphA4 ligand, EphrinB3, from embryonic day 12.5. Therefore, we tested whether EphA4-deficient mice (EphA4(-/-) ) would show impairment in the development of olivocerebellar projections. We found that, in EphA4(-/-) embryos, some of the IO neurons projected their axons to the ipsilateral cerebellar cortex because the cell bodies of the IO neurons abnormally crossed the FP. Furthermore, even in adults, EphA4(-/-) cerebella were bilaterally innervated by unilateral IO subnuclei. These observations indicate that EphA4 is involved in the contralateral axonal projections of IO neurons by preventing their cell bodies from crossing the midline FP.
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13
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Eph/ephrin signaling in epidermal differentiation and disease. Semin Cell Dev Biol 2011; 23:92-101. [PMID: 22040910 DOI: 10.1016/j.semcdb.2011.10.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 10/17/2011] [Indexed: 01/09/2023]
Abstract
Eph receptor tyrosine kinases mediate cell-cell communication by interacting with ephrin ligands residing on adjacent cell surfaces. In doing so, these juxtamembrane signaling complexes provide important contextual information about the cellular microenvironment that helps orchestrate tissue morphogenesis and maintain homeostasis. Eph/ephrin signaling has been implicated in various aspects of mammalian skin physiology, with several members of this large family of receptor tyrosine kinases and their ligands present in the epidermis, hair follicles, sebaceous glands, and underlying dermis. This review focuses on the emerging role of Eph receptors and ephrins in epidermal keratinocytes where they can modulate proliferation, migration, differentiation, and death. The activation of Eph receptors by ephrins at sites of cell-cell contact also appears to play a key role in the maturation of intercellular junctional complexes as keratinocytes move out of the basal layer and differentiate in the suprabasal layers of this stratified, squamous epithelium. Furthermore, alterations in the epidermal Eph/ephrin axis have been associated with cutaneous malignancy, wound healing defects and inflammatory skin conditions. These collective observations suggest that the Eph/ephrin cell-cell communication pathway may be amenable to therapeutic intervention for the purpose of restoring epidermal tissue homeostasis and integrity in dermatological disorders.
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Arocho LC, Figueroa JD, Torrado AI, Santiago JM, Vera AE, Miranda JD. Expression profile and role of EphrinA1 ligand after spinal cord injury. Cell Mol Neurobiol 2011; 31:1057-69. [PMID: 21603973 DOI: 10.1007/s10571-011-9705-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 04/30/2011] [Indexed: 10/18/2022]
Abstract
Spinal cord injury (SCI) triggers the re-expression of inhibitory molecules present in early stages of development, contributing to prevention of axonal regeneration. Upregulation of EphA receptor tyrosine kinases after injury suggest their involvement in the nervous system's response to damage. However, the expression profile of their ephrinA ligands after SCI is unclear. In this study, we determined the expression of ephrinA ligands after contusive SCI. Adult Sprague-Dawley female rats were injured using the MASCIS impactor device at the T10 vertebrae, and levels of ephrinA mRNA and protein determined at different time points. Identification of the cell phenotype expressing the ephrin ligand and colocalization with Eph receptors was performed with immunohistochemistry and confocal microscopy. Behavioral studies were made, after blocking ephrinA1 expression with antisense (AS) oligonucleotides, to assess hindlimb locomotor activity. Real-time PCR demonstrated basal mRNA levels of ephrin (A1, A2, A3, and A5) in the adult spinal cord. Interestingly, ephrinA1 was the only ligand whose mRNA levels were significantly altered after SCI. Although ephrinA1 mRNA levels increased after 2 weeks and remain elevated, we did not observe this pattern at the protein level as revealed by western blot analysis. Immunohistochemical studies showed ephrinA1 expression in reactive astrocytes, axons, and neurons and also their colocalization with EphA4 and A7 receptors. Behavioral studies revealed worsening of locomotor activity when ephrinA1 expression was reduced. This study suggests that ephrinA1 ligands play a role in the pathophysiology of SCI.
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Affiliation(s)
- Luz C Arocho
- Physiology Department, University of Puerto Rico School of Medicine, P.O. Box 365067, San Juan, PR 00936-5067, USA
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