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Wang J, Wei Q, Yang Y, Che M, Ma Y, Peng L, Yu H, Shi H, He G, Wu R, Zeng T, Zeng X, Ma W. Small extracellular vesicles derived from four dimensional-culture of mesenchymal stem cells induce alternatively activated macrophages by upregulating IGFBP2/EGFR to attenuate inflammation in the spinal cord injury of rats. Front Bioeng Biotechnol 2023; 11:1146981. [PMID: 37187882 PMCID: PMC10176095 DOI: 10.3389/fbioe.2023.1146981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023] Open
Abstract
Effectively reducing the inflammatory response after spinal cord injury (SCI) is a challenging clinical problem and the subject of active investigation. This study employed a porous scaffold-based three dimensional long-term culture technique to obtain human umbilical cord mesenchymal stem cell (hUC-MSC)-derived Small Extracellular Vesicles (sEVs) (three dimensional culture over time, the "4D-sEVs"). Moreover, the vesicle size, number, and inner protein concentrations of the MSC 4D-sEVs contained altered protein profiles compared with those derived from 2D culture conditions. A proteomics analysis suggested broad changes, especially significant upregulation of Epidermal Growth Factors Receptor (EGFR) and Insulin-like Growth Factor Binding Protein 2 (IGFBP2) in 4D-sEVs compared with 2D-sEVs. The endocytosis of 4D-sEVs allowed for the binding of EGFR and IGFBP2, leading to downstream STAT3 phosphorylation and IL-10 secretion and effective induction of macrophages/microglia polarization from the pro-inflammatory M1 to anti-inflammatory M2 phenotype, both in vitro and in the injured areas of rats with compressive/contusive SCI. The reduction in neuroinflammation after 4D-sEVs delivery to the injury site epicenter led to significant neuroprotection, as evidenced by the number of surviving spinal neurons. Therefore, applying this novel 4D culture-derived Small Extracellular Vesicles could effectively curb the inflammatory response and increase tissue repair after SCI.
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Affiliation(s)
- Junhua Wang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qingshuai Wei
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Yue Yang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Mingtian Che
- Biobank and Pathology Shared Resources, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Yuanhuan Ma
- Guangzhou Institute of Clinical Medicine, Guangzhou First People’s Hospital, South China University of Technology, Guangzhou, China
| | - Lizhi Peng
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Haiyang Yu
- Department of Orthopedics, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Huijuan Shi
- Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Guanheng He
- Department of Acupuncture, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Rongjie Wu
- Department of Orthopedics, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Ting Zeng
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiang Zeng
- Lab of Stem Cell Biology and Innovative Research of Chinese Medicine, National Institute of Stem Cell Clinical Research, Guangdong Provincial Hospital of Chinese Medicine/Guangdong Academy of Chinese Medicine/The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- *Correspondence: Wenbin Ma, ; Xiang Zeng,
| | - Wenbin Ma
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Wenbin Ma, ; Xiang Zeng,
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Wang GY, Cheng ZJ, Yuan PW, Li HP, He XJ. Olfactory ensheathing cell transplantation alters the expression of chondroitin sulfate proteoglycans and promotes axonal regeneration after spinal cord injury. Neural Regen Res 2021; 16:1638-1644. [PMID: 33433495 PMCID: PMC8323695 DOI: 10.4103/1673-5374.301023] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cell transplantation is a potential treatment for spinal cord injury. Olfactory ensheathing cells (OECs) play an active role in the repair of spinal cord injury as a result of the dual characteristics of astrocytes and Schwann cells. However, the specific mechanisms of repair remain poorly understood. In the present study, a rat model of spinal cord injury was established by transection of T10. OECs were injected into the site, 1 mm from the spinal cord stump. To a certain extent, OEC transplantation restored locomotor function in the hindlimbs of rats with spinal cord injury, but had no effect on the formation or volume of glial scars. In addition, OEC transplantation reduced the immunopositivity of chondroitin sulfate proteoglycans (neural/glial antigen 2 and neurocan) and glial fibrillary acidic protein at the injury site, and increased the immunopositivity of growth-associated protein 43 and neurofilament. These findings suggest that OEC transplantation can regulate the expression of chondroitin sulfate proteoglycans in the spinal cord, inhibit scar formation caused by the excessive proliferation of glial cells, and increase the numbers of regenerated nerve fibers, thus promoting axonal regeneration after spinal cord injury. The study was approved by the Animal Ethics Committee of the Medical College of Xi’an Jiaotong University, China (approval No. 2018-2048) on September 9, 2018.
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Affiliation(s)
- Guo-Yu Wang
- Second Department of Orthopedics, the Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Zhi-Jian Cheng
- Second Department of Orthopedics, the Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Pu-Wei Yuan
- Second Department of Orthopedics, the Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Hao-Peng Li
- Second Department of Orthopedics, the Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Xi-Jing He
- Second Department of Orthopedics, the Second Hospital of Xi'an Jiaotong University; Xi'an International Medical Center Orthopedic Hospital, Xi'an, Shaanxi Province, China
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Kirazlı Ö, Solmaz B, Çavdar S. The contributions to the human dorsal column tracts from the spinal cord laminae. J Integr Neurosci 2016; 15:337-345. [PMID: 27774835 DOI: 10.1142/s0219635216500217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dorsal column tracts (fasciculus gracilis and fasciculus cuneatus) are concerned with discriminative qualities of sensation. There are controversial descriptions related to the relations of dorsal column tracts with the dorsal horn laminae in text-books. The present study aims to define the laminae of the dorsal horn of the spinal cord that contribute fibers to the dorsal column tracts in the cervical, thoracic and lumbar spinal level. Series paraffin spinal cords sections of six formalin-embalmed adult human cadavers were evaluated. The present study shows that dorsal column tracts receive fiber contributions from laminae III and V and from Clarke's dorsal nucleus at varying spinal levels. At upper cervical levels (C1-C4) fiber contributions were from lamina V and few from lamina III, and at lower cervical levels (C5-C8) there were, in addition to these laminae, also contributions from the Clarke's dorsal nucleus. At upper thoracic levels (T1-T4) fiber contributions were from lamina V and few from Clarke's dorsal nucleus. At lower thoracic (T5-T12) and lumbar levels (L1-L5), in contrast, fiber contributions were only from Clarke's dorsal nucleus. The detailed knowledge of organization of the dorsal column tracts of the spinal cord may pave the way for future treatments of the spinal cord injuries.
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Affiliation(s)
- Özlem Kirazlı
- * Department of Anatomy, School of Medicine, Marmara University, Istanbul, Turkey
| | - Bilgehan Solmaz
- † Department of Neurosurgery, Istanbul Education and Research Hospital, Istanbul, Turkey
| | - Safiye Çavdar
- ‡ Department of Anatomy, School of Medicine, Koç University, 34450 Sarıyer, Istanbul, Turkey
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Kraus KS, Ding D, Jiang H, Kermany MH, Mitra S, Salvi RJ. Up-regulation of GAP-43 in the chinchilla ventral cochlear nucleus after carboplatin-induced hearing loss: correlations with inner hair cell loss and outer hair cell loss. Hear Res 2013; 302:74-82. [PMID: 23707995 DOI: 10.1016/j.heares.2013.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 04/18/2013] [Accepted: 05/06/2013] [Indexed: 12/11/2022]
Abstract
Inner ear damage leads to nerve fiber growth and synaptogenesis in the ventral cochlear nucleus (VCN). In this study, we documented the relationship between hair cell loss patterns and synaptic plasticity in the chinchilla VCN using immunolabeling of the growth associated protein-43 (GAP-43), a protein associated with axon outgrowth and modification of presynaptic endings. Unilateral round window application of carboplatin caused hair cell degeneration in which inner hair cells (IHC) were more vulnerable than outer hair cells (OHC). One month after carboplatin treatment (0.5-5 mg/ml), we observed varying patterns of cochlear hair cell loss and GAP-43 expression in VCN. Both IHC loss and OHC loss were strongly correlated with increased GAP-43 immunolabeling in the ipsilateral VCN. We speculate that two factors might promote the expression of GAP-43 in the VCN; one is the loss of afferent input through IHC or the associated type I auditory nerve fibers. The other occurs when the medial olivocochlear efferent neurons lose their cochlear targets, the OHC, and may as compensation increase their synapse numbers in the VCN.
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Affiliation(s)
- K S Kraus
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
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Murray M, Santi L, Monaghan R, Houle JD, Barr GA. Peripheral nerve graft with immunosuppression modifies gene expression in axotomized CNS neurons. J Comp Neurol 2012; 519:3433-55. [PMID: 21800297 DOI: 10.1002/cne.22714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Adult central nervous system (CNS) neurons do not regenerate severed axons unaided but may regenerate axons into apposed predegenerated peripheral nerve grafts (PNGs). We examined gene expression by using microarray technology in laser-dissected lateral vestibular (LV) neurons whose axons were severed by a lateral hemisection at C3 (HX) and in lateral vestibular nucleus (LVN) neurons that were hemisected at C3 and that received immunosuppression with cyclosporine A (CsA) and a predegenerated PNG (termed I-PNG) into the lesion site. The results provide an expression analysis of temporal changes that occur in LVN neurons in nonregenerative and potentially regenerative states and over a period of 42 days. Axotomy alone resulted in a prolonged change in regulation of probe sets, with more being upregulated than downregulated. Apposition of a PNG with immunosuppression muted gene expression overall. Axotomized neurons (HX) upregulated genes commonly associated with axonal growth, whereas axotomized neurons whose axons were apposed to the PNG showed diminished expression of many of these genes but greater expression of genes related to energy production. The results suggest that axotomized LVN neurons express many genes thought to be associated with regeneration to a greater extent than LVN neurons that are apposed to a PNG. Thus the LVN neurons remain in a regenerative state following axotomy but the conditions provided by the I-PNG appear to be neuroprotective, preserving or enhancing mitochondrial activity, which may provide required energy for regeneration. We speculate that the graft also enables sufficient axonal synthesis of cytoskeletal components to allow axonal growth without marked increase in expression of genes normally associated with regeneration.
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Affiliation(s)
- Marion Murray
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA.
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Kraus KS, Ding D, Jiang H, Lobarinas E, Sun W, Salvi RJ. Relationship between noise-induced hearing-loss, persistent tinnitus and growth-associated protein-43 expression in the rat cochlear nucleus: does synaptic plasticity in ventral cochlear nucleus suppress tinnitus? Neuroscience 2011; 194:309-25. [PMID: 21821100 PMCID: PMC3390756 DOI: 10.1016/j.neuroscience.2011.07.056] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/22/2011] [Accepted: 07/23/2011] [Indexed: 10/17/2022]
Abstract
Aberrant, lesion-induced neuroplastic changes in the auditory pathway are believed to give rise to the phantom sound of tinnitus. Noise-induced cochlear damage can induce extensive fiber growth and synaptogenesis in the cochlear nucleus, but it is currently unclear if these changes are linked to tinnitus. To address this issue, we unilaterally exposed nine rats to narrow-band noise centered at 12 kHz at 126 dB sound pressure level (SPL) for 2 h and sacrificed them 10 weeks later for evaluation of synaptic plasticity (growth-associated protein 43 [GAP-43] expression) in the cochlear nucleus. Noise-exposed rats along with three age-matched controls were screened for tinnitus-like behavior with gap prepulse inhibition of the acoustic startle (GPIAS) before, 1-10 days after, and 8-10 weeks after the noise exposure. All nine noise-exposed rats showed similar patterns of severe hair cell loss at high- and mid-frequency regions in the exposed ear. Eight of the nine showed strong up-regulation of GAP-43 in auditory nerve fibers and pronounced shrinkage of the ventral cochlear nucleus (VCN) on the noise-exposed side, and strong up-regulation of GAP-43 in the medial ventral VCN, but not in the lateral VCN or the dorsal cochlear nucleus. GAP-43 up-regulation in VCN was significantly greater in Noise-No-Tinnitus rats than in Noise-Tinnitus rats. One Noise-No-Tinnitus rat showed no up-regulation of GAP-43 in auditory nerve fibers and only little VCN shrinkage, suggesting that auditory nerve degeneration plays a role in tinnitus generation. Our results suggest that noise-induced tinnitus is suppressed by strong up-regulation of GAP-43 in the medial VCN. GAP-43 up-regulation most likely originates from medial olivocochlear neurons. Their increased excitatory input on inhibitory neurons in VCN may possibly reduce central hyperactivity and tinnitus.
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Affiliation(s)
- Kari Suzanne Kraus
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States
| | - Dalian Ding
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States
| | - Haiyan Jiang
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States
| | - Ed Lobarinas
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States
| | - Wei Sun
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States
| | - Richard J Salvi
- Center for Hearing and Deafness, SUNY at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States
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Inhibiting epidermal growth factor receptor attenuates reactive astrogliosis and improves functional outcome after spinal cord injury in rats. Neurochem Int 2011; 58:812-9. [PMID: 21402118 DOI: 10.1016/j.neuint.2011.03.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Revised: 02/06/2011] [Accepted: 03/06/2011] [Indexed: 11/20/2022]
Abstract
As a physical barrier to regenerating axons, reactive astrogliosis is also a biochemical barrier which can secrete inhibitory molecules, including chondroitin sulfate proteoglycans (CSPGs) in the pathological mechanism of spinal cord injury (SCI). Thus, inhibition of astroglial proliferation and CSPG production might facilitate axonal regeneration after SCI. Recent studies have demonstrated that epidermal growth factor receptor (EGFR) activation triggers quiescent astrocytes into becoming reactive astrocytes and forming glial scar after CNS injury. In the present study, we investigated whether a specific EGFR inhibitor (AG1478) could attenuate the reactive astrogliosis and production of CSPGs, alleviate demyelination, and eventually enhance the functional recovery after SCI in rats. Our results showed that pEGFR immunoreactivity was up-regulated significantly post injury, mainly confined to astrocytes. Meanwhile, astrocytes near the injury site after SCI became activated obviously characterized by hypertrophic morphology and enhanced GFAP expression. However, administration of AG1478 remarkably reduced trauma induced-reactive astrogliosis and accumulation of CSPGs. Furthermore, the treatment with AG1478 also alleviated demyelination, increased expression of growth-associated proteins-43 (GAP-43) and improved hindlimb function after SCI. Therefore, the local blockade of EGFR in an injured area is beneficial to functional outcome by facilitating a more favorable environment for axonal regeneration in SCI rats.
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Fleisch VC, Fraser B, Allison WT. Investigating regeneration and functional integration of CNS neurons: lessons from zebrafish genetics and other fish species. Biochim Biophys Acta Mol Basis Dis 2010; 1812:364-80. [PMID: 21044883 DOI: 10.1016/j.bbadis.2010.10.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 10/05/2010] [Accepted: 10/21/2010] [Indexed: 12/21/2022]
Abstract
Zebrafish possess a robust, innate CNS regenerative ability. Combined with their genetic tractability and vertebrate CNS architecture, this ability makes zebrafish an attractive model to gain requisite knowledge for clinical CNS regeneration. In treatment of neurological disorders, one can envisage replacing lost neurons through stem cell therapy or through activation of latent stem cells in the CNS. Here we review the evidence that radial glia are a major source of CNS stem cells in zebrafish and thus activation of radial glia is an attractive therapeutic target. We discuss the regenerative potential and the molecular mechanisms thereof, in the zebrafish spinal cord, retina, optic nerve and higher brain centres. We evaluate various cell ablation paradigms developed to induce regeneration, with particular emphasis on the need for (high throughput) indicators that neuronal regeneration has restored sensory or motor function. We also examine the potential confound that regeneration imposes as the community develops zebrafish models of neurodegeneration. We conclude that zebrafish combine several characters that make them a potent resource for testing hypotheses and discovering therapeutic targets in functional CNS regeneration. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases.
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Affiliation(s)
- Valerie C Fleisch
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, Alberta, Canada.
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Huang X, Kim JM, Kong TH, Park SR, Ha Y, Kim MH, Park H, Yoon SH, Park HC, Park JO, Min BH, Choi BH. GM-CSF inhibits glial scar formation and shows long-term protective effect after spinal cord injury. J Neurol Sci 2008; 277:87-97. [PMID: 19033079 DOI: 10.1016/j.jns.2008.10.022] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 10/13/2008] [Accepted: 10/17/2008] [Indexed: 11/19/2022]
Abstract
OBJECT This study investigated the effects of granulocyte macrophage-colony stimulating factor (GM-CSF) on the scar formation and repair of spinal cord tissues in rat spinal cord injury (SCI) model. METHODS Sprague-Dawley male rats (8 weeks old) were randomly divided into the sham-operated group, spinal cord injury group, and injury with GM-CSF treated group. A spinal cord injury was induced at T9/10 levels of rat spinal cord using a vascular clip. GM-CSF was administrated via intraperitoneal (IP) injection or on the dural surface using Gelfoam at the time of SCI. The morphological changes, tissue integrity, and scar formation were evaluated until 4 weeks after SCI using histological and immunohistochemical analyses. RESULTS The administration of GM-CSF either via IP injection or local treatment significantly reduced the cavity size and glial scar formation at 3-4 weeks after SCI. GM-CSF also reduced the expression of core proteins of chondroitin sulfate proteoglycans (CSPGs) such as neurocan and NG2 but not phosphacan. In particular, an intensive expression of glial fibriallary acidic protein (GFAP) and neurocan found around the cavity at 4 weeks was obviously suppressed by GM-CSF. Immunostaining for neurofilament (NF) and Luxol fast blue (LFB) showed that GM-CSF preserved well the axonal arrangement and myelin structure after SCI. The expression of GAP-43, a marker of regenerating axons, also apparently increased in the rostral grey matter by GM-CSF. CONCLUSION These results suggest that GM-CSF could enhance long-term recovery from SCI by suppressing the glial scar formation and enhancing the integrity of axonal structure.
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Affiliation(s)
- Xian Huang
- Department of Neurosurgery, Inha University College of Medicine, Incheon, Republic of Korea
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Geranmayeh F, Scheithauer BW, Spitzer C, Meyer FB, Svensson-Engwall AC, Graeber MB. MICROGLIA IN GEMISTOCYTIC ASTROCYTOMAS. Neurosurgery 2007; 60:159-66; discussion 166. [PMID: 17228265 DOI: 10.1227/01.neu.0000249192.30786.67] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Although gemistocytic astrocytomas are graded as World Health Organization II astrocytomas, they behave more aggressively than other astrocytomas. Their proliferative potential is low, and it remains an intriguing question why these tumors are so biologically "successful." They show a high mutation rate of the P53 gene, cytological abnormalities, and frequent perivascular mononuclear infiltrates. Microglial cells, a feature of this astrocytoma variant, are of increasing interest in the context of glioma growth. METHODS We selected 23 tumor biopsies from 201 samples obtained from patients with gemistocytic astrocytomas operated at Mayo Clinic between 1985 and 1998. These tumors were formerly analyzed for P53 mutations, p53 protein, and proliferative activity (). Immunolabeling for three microglial markers, including CR3/43, Ki-M1P, and iba1, was performed on adjacent tissue sections. In addition, in situ hybridization for the alpha-chain of the major histocompatibility complex (MHC) Class II molecule recognized by the CR3/43 monoclonal antibody was performed. RESULTS A high number of microglia was detected in gemistocytic astrocytomas. More microglia were present if the fraction of gemistocytic tumor cells was high (correlation coefficient = 0.699; P < 0.0002). Interestingly, a number of gemistocytes were immunoreactive for MHC Class II molecules, an observation confirmed by in situ hybridization. Importantly, the higher the number of Class II immunoreactive gemistocytes, the fewer Class II positive microglial cells could be detected (correlation coefficient = -0.5649; P < 0.005). CONCLUSION Our results support the view that gemistocytic astrocytomas contain unusually high numbers of microglial cells. We propose that the finding of aberrant MHC Class II expression by gemistocytic tumor cells correlates with a loss of immune-competent MHC Class II-expressing microglia. This may be related to the especially poor prognosis of gemistocytic astrocytomas for which induction of T cell anergy could provide one explanation.
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Affiliation(s)
- Fatemeh Geranmayeh
- University Department of Neuropathology, Imperial College London, Faculty of Medicine, Division of Neuroscience and Mental Health, Hammersmith Hospitals Trust, London, England
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Harel NY, Strittmatter SM. Can regenerating axons recapitulate developmental guidance during recovery from spinal cord injury? Nat Rev Neurosci 2006; 7:603-16. [PMID: 16858389 PMCID: PMC2288666 DOI: 10.1038/nrn1957] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The precise wiring of the adult mammalian CNS originates during a period of stunning growth, guidance and plasticity that occurs during and shortly after development. When injured in adults, this intricate system fails to regenerate. Even when the obstacles to regeneration are cleared, growing adult CNS fibres usually remain misdirected and fail to reform functional connections. Here, we attempt to fill an important niche related to the topics of nervous system development and regeneration. We specifically contrast the difficulties faced by growing fibres within the adult context to the precise circuit-forming capabilities of developing fibres. In addition to focusing on methods to stimulate growth in the adult, we also expand on approaches to recapitulate development itself.
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Affiliation(s)
- Noam Y Harel
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Neurology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Flügel A, Schwaiger FW, Neumann H, Medana I, Willem M, Wekerle H, Kreutzberg GW, Graeber MB. Neuronal FasL induces cell death of encephalitogenic T lymphocytes. Brain Pathol 2006; 10:353-64. [PMID: 10885654 PMCID: PMC8098261 DOI: 10.1111/j.1750-3639.2000.tb00267.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Apoptosis of inflammatory cells plays a crucial role in the recovery from autoimmune CNS disease. However, the underlying mechanisms of apoptosis induction are as yet ill-defined. Here we report on the neuronal expression of FasL and its potential function in inducing T-cell apoptosis. Using a combination of facial nerve axotomy and passive transfer encephalomyelitis, the fate of CD4+ encephalitogenic T cells engineered to express the gene for green fluorescent protein was followed. FasL gene transcripts and FasL protein were detected in neurons by in sit-hybridization and immunohistochemistry. T cells infiltrating preferentially the injured brain parenchyma were found in the immediate vicinity of FasL expressing neurons and even inside their perikarya. In contrast to neurons, T cells rapidly underwent apoptosis. In co-cultures of hippocampal nerve cells and CD4 T lymphocytes, we confirmed expression of FasL in neurons and concomitant induction of T-cell death. Antibodies blocking neuronal FasL were shown to have a protective effect on T-cell survival. Thus, FasL expression by neurons in neuroinflammatory diseases may constitute a pivotal mechanism underlying apoptosis of encephalitogenic T cells.
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Affiliation(s)
- A Flügel
- Department of Neuroimmunology, Max-Planck-Institute of Neurobiology, Martinsried, FRG
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Hoang TX, Nieto JH, Havton LA. Regenerating supernumerary axons are cholinergic and emerge from both autonomic and motor neurons in the rat spinal cord. Neuroscience 2005; 136:417-23. [PMID: 16203105 DOI: 10.1016/j.neuroscience.2005.08.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 07/26/2005] [Accepted: 08/01/2005] [Indexed: 11/26/2022]
Abstract
Multipolar neurons in the mammalian nervous system normally exhibit one axon and several dendrites. However, in response to an axonal injury, adult motoneurons may regenerate supernumerary axons. Supernumerary axons emerge from the cell body or dendritic trees in addition to the stem motor axon. It is not known whether these regenerating axons contain neurotransmitters for synaptic transmission at their terminals. Here, using immunohistochemistry for choline acetyltransferase, an enzyme that synthesizes acetylcholine, we demonstrate the emergence of cholinergic supernumerary axons at 6 weeks after a unilateral L5-S2 ventral root avulsion and acute implantation of the avulsed L6 ventral root into the adult rat spinal cord. Light microscopic serial reconstruction of choline acetyltransferase immunoreactive arbors shows that these supernumerary axons originate from both autonomic and motor neurons. The supernumerary axons emerge from the cell body or dendrites, exhibit an abnormal projection pattern within the intramedullary gray and white matters, make frequent abrupt turns in direction, and form bouton-like swellings as well as growth cone-like terminals. Double labeling immunohistochemistry studies show that the choline acetyltransferase immunoreactive supernumerary axons co-localized with two proteins associated with axonal growth and elongation, growth-associated protein 43 and p75, the low affinity neurotrophic factor receptor. Our findings suggest that regenerating supernumerary axons selectively transport and store choline acetyltransferase, supporting the notion that supernumerary axons may develop functional and active synaptic transmission. Therefore, regenerating supernumerary axons may contribute to the plasticity in neural circuits following injury in the adult nervous system.
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Affiliation(s)
- T X Hoang
- Department of Neurology and Brain Research Institute, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095-1769, USA
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Illing RB, Kraus KS, Meidinger MA. Reconnecting neuronal networks in the auditory brainstem following unilateral deafening. Hear Res 2005; 206:185-99. [PMID: 16081008 DOI: 10.1016/j.heares.2005.01.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Accepted: 01/10/2005] [Indexed: 11/27/2022]
Abstract
When we disturbed the auditory input of the adult rat by cochleotomy or noise trauma on one side, several substantial anatomical, cellular, and molecular changes took place in the auditory brainstem. We found that: (1) cochleotomy or severe noise trauma both lead to a considerable increase of immunoreactivity of the growth-associated protein GAP-43 in the ventral cochlear nucleus (VCN) of the affected side; (2) the expression of GAP-43 in VCN is restricted to presynaptic endings and short fiber segments; (3) axon collaterals of the cholinergic medial olivocochlear (MOC) neurons are the path along which GAP-43 reaches VCN; (4) partial cochlear lesions induce the emergence of GAP-43 positive presynaptic endings only in regions tonotopically corresponding to the extent of the lesion; (5) judging from the presence of immature fibers and growth cones in VCN on the deafened side, at least part of the GAP-43 positive presynaptic endings appear to be newly formed neuronal contacts following axonal sprouting while others may be modified pre-existing contacts; and (6) GAP-43 positive synapses are formed only on specific postsynaptic profiles, i.e., glutamatergic, glycinergic and calretinin containing cell bodies, but not GABAergic cell bodies. We conclude that unilateral deafening, be it partial or total, induces complex patterns of reconnecting neurons in the adult auditory brainstem, and we evaluate the possibility that the deafness-induced chain of events is optimized to remedy the loss of a bilaterally balanced activity in the auditory brainstem.
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Affiliation(s)
- Robert-Benjamin Illing
- Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, D-79106 Freiburg, Germany.
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15
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Woodhouse A, West AK, Chuckowree JA, Vickers JC, Dickson TC. Does beta-amyloid plaque formation cause structural injury to neuronal processes? Neurotox Res 2005; 7:5-15. [PMID: 15639794 DOI: 10.1007/bf03033772] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The precise role of beta-amyloid plaque formation in the cascade of brain cell changes that lead to neurodegeneration and dementia in Alzheimer's disease has been unclear. Studies have indicated that neuronal processes surrounding and within plaques undergo a series of biochemical and morphological alterations. Morphological alterations include reactive, degenerative and sprouting-related 'dystrophic' neuritic structures, derived principally from axons, which involve specific changes in cytoskeletal proteins such as tau and NF triplet proteins. More compact and fibrous plaques are associated with more extensive neuritic pathology than non-fibrillar, diffuse beta-amyloid deposits. Cortical apical dendritic processes are either 'clipped' by plaque formation or are bent around more compact plaques. Examination of cases of 'pathological' brain ageing, which may represent a preclinical form of Alzheimer's disease, demonstrated that the earliest neuritic pathology associated with plaques was similar to the reactive changes that follow structural injury to axons. In vivo and in vitro experimental models of structural injury to axons produce identical reactive changes that subsequently lead to an attempt at regenerative sprouting by damaged axons. Thus, beta-amyloid plaque formation may cause structural injury to axons that is subsequently followed by an aberrant sprouting response that presages neurodegeneration and dementia. Identification of the key neuronal alterations underlying the pathology of Alzheimer's disease may provide new avenues for therapeutic intervention.
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Affiliation(s)
- Adele Woodhouse
- NeuroRepair Group, School of Medicine, University of Tasmania, Australia
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16
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Kraus KS, Illing RB. Cell death or survival: Molecular and connectional conditions for olivocochlear neurons after axotomy. Neuroscience 2005; 134:467-81. [PMID: 15964701 DOI: 10.1016/j.neuroscience.2005.04.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 03/24/2005] [Accepted: 04/12/2005] [Indexed: 12/11/2022]
Abstract
We aimed to determine whether rat olivocochlear neurons survive axotomy inflicted through cochlear ablation, or if they degenerate. To estimate their intrinsic potential for axonal regeneration, we investigated the expression of the transcription factor c-Jun and the growth-associated protein-43 (GAP43). Axonal tracing studies based on application of Fast Blue into the cochlea and calcitonin gene-related peptide immunostaining revealed that many, but not all, lateral olivocochlear neurons in the ipsilateral lateral superior olive degenerated upon cochleotomy. A decrease of their number was noticed 2 weeks after the lesion, and 2 months postoperative the population was reduced to approximately one quarter (27-29%) of its original size. No further reduction took place at longer survival times up to 1 year. Most or all shell neurons and medial olivocochlear neurons survived axotomy. Following cochleotomy, 56-60% of the lateral olivocochlear neurons in the ipsilateral lateral superior olive were found to co-express c-Jun and GAP43. Only a small number of shell and medial olivocochlear neurons up-regulated c-Jun expression, and only a small number of shell neurons expressed GAP43. Up-regulation of c-Jun and GAP43 in lateral olivocochlear neurons upon axotomy suggests that they have an intrinsic potential to regenerate after axotomy, but cell counts based on the markers Fast Blue and calcitonin gene-related peptide indicate that this potential cannot be exploited and degeneration is induced instead. The survival of one quarter of the axotomized lateral olivocochlear neurons and of all, or almost all, shell and medial olivocochlear neurons appeared to depend on connections of these cells to other regions than the cochlea by means of axon collaterals, which remained intact after cochleotomy.
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Affiliation(s)
- K S Kraus
- Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, Killianstrasse 5, D-79106 Freiburg, Germany
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17
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Bareyre FM, Schwab ME. Inflammation, degeneration and regeneration in the injured spinal cord: insights from DNA microarrays. Trends Neurosci 2003; 26:555-63. [PMID: 14522149 DOI: 10.1016/j.tins.2003.08.004] [Citation(s) in RCA: 211] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
GeneChip microarrays have recently been introduced to the field of neurobiology to identify and monitor the expression levels of thousands of genes simultaneously. This powerful technique is now used for studying the pathophysiology of CNS injuries including spinal cord lesions. Early stages after injury are characterized by the strong upregulation of genes involved in transcription and inflammation and a general downregulation of structural proteins and proteins involved in neurotransmission. Later, an increase in the expression of growth factors, axonal guidance factors, extracellular matrix molecules and angiogenic factors reflects the attempts for repair, while upregulation of stress genes and proteases and downregulation of cytoskeletal and synaptic mRNA reflect the struggle of the tissue to survive. DNA microarrays have the potential to aid discovery of new targets for neuroprotective or restorative therapeutic approaches
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Affiliation(s)
- Florence M Bareyre
- Brain Research Institute, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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18
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Emery DL, Royo NC, Fischer I, Saatman KE, McIntosh TK. Plasticity following Injury to the Adult Central Nervous System: Is Recapitulation of a Developmental State Worth Promoting? J Neurotrauma 2003; 20:1271-92. [PMID: 14748977 DOI: 10.1089/089771503322686085] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The adult central nervous system (CNS) appears to initiate a transient increase in plasticity following injury, including increases in growth-related proteins and generation of new cells. Recent evidence is reviewed that the injured adult CNS exhibits events and patterns of gene expression that are also observed during development and during regeneration following damage to the mature peripheral nervous system (PNS). The growth of neurons during development or regeneration is correlated, in part, with a coordinated expression of growth-related proteins, such as growth-associated-protein-43 (GAP-43), microtubule-associated-protein-1B (MAP1B), and polysialylated-neural-cell-adhesion-molecule (PSA-NCAM). For each of these proteins, evidence is discussed regarding its specific role in neuronal development, signals that modify its expression, and reappearance following injury. The rate of adult hippocampal neurogenesis is also affected by numerous endogenous and exogenous factors including injury. The continuing study of developmental neurobiology will likely provide further gene and protein targets for increasing plasticity and regeneration in the mature adult CNS.
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Affiliation(s)
- Dana L Emery
- Head Injury Center, Department of Neurosurgery, University of Pennsylvania, USA
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19
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Schmitt AB, Breuer S, Polat L, Pech K, Kakulas B, Love S, Martin D, Schoenen J, Noth J, Brook GA. Retrograde reactions of Clarke's nucleus neurons after human spinal cord injury. Ann Neurol 2003; 54:534-9. [PMID: 14520670 DOI: 10.1002/ana.10724] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Successful axon regeneration depends on the expression of regeneration-associated genes by axotomized neurons. Here, we demonstrate, for the first time to our knowledge, the expression of regeneration-associated genes by axotomized human CNS neurons. In situ hybridization and immunohistochemistry showed a transient induction of GAP-43 and c-jun in Clarke's nucleus neurons caudal to traumatic human spinal cord injury. These results support experimental data that nonregenerating central nervous system neurons can temporarily upregulate regeneration-associated genes, reflecting a transient regenerative capacity that fails over time.
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Affiliation(s)
- Andreas B Schmitt
- Aachen Spinal Cord Research Center, Department of Neurology, University Hospital Aachen, Aachen, Germany.
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20
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Schmitt AB, Breuer S, Liman J, Buss A, Schlangen C, Pech K, Hol EM, Brook GA, Noth J, Schwaiger FW. Identification of regeneration-associated genes after central and peripheral nerve injury in the adult rat. BMC Neurosci 2003; 4:8. [PMID: 12756057 PMCID: PMC161801 DOI: 10.1186/1471-2202-4-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2002] [Accepted: 05/19/2003] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND It is well known that neurons of the peripheral nervous system have the capacity to regenerate a severed axon leading to functional recovery, whereas neurons of the central nervous system do not regenerate successfully after injury. The underlying molecular programs initiated by axotomized peripheral and central nervous system neurons are not yet fully understood. RESULTS To gain insight into the molecular mechanisms underlying the process of regeneration in the nervous system, differential display polymerase chain reaction has been used to identify differentially expressed genes following axotomy of peripheral and central nerve fibers. For this purpose, axotomy induced changes of regenerating facial nucleus neurons, and non-regenerating red nucleus and Clarke's nucleus neurons have been analyzed in an intra-animal side-to-side comparison. One hundred and thirty five gene fragments have been isolated, of which 69 correspond to known genes encoding for a number of different functional classes of proteins such as transcription factors, signaling molecules, homeobox-genes, receptors and proteins involved in metabolism. Sixty gene fragments correspond to genomic mouse sequences without known function. In situ-hybridization has been used to confirm differential expression and to analyze the cellular localization of these gene fragments. Twenty one genes (approximately 15%) have been demonstrated to be differentially expressed. CONCLUSIONS The detailed analysis of differentially expressed genes in different lesion paradigms provides new insights into the molecular mechanisms underlying the process of regeneration and may lead to the identification of genes which play key roles in functional repair of central nervous tissues.
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Affiliation(s)
- Andreas B Schmitt
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Sebastian Breuer
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Jan Liman
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Armin Buss
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Christiane Schlangen
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Katrin Pech
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Elly M Hol
- Netherlands Institute for Brain Research, 1105 AZ Amsterdam, The Netherlands
| | - Gary A Brook
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Johannes Noth
- Department of Neurology, Aachen University Medical School, Pauwelsstrasse 30, 52057 Aachen, Germany
| | - Franz-Werner Schwaiger
- Department of Neuromorphology, Max-Planck-Institute of Neurobiology, 82152 Martinsried, Germany
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21
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Carulli D, Buffo A, Botta C, Altruda F, Strata P. Regenerative and survival capabilities of Purkinje cells overexpressing c-Jun. Eur J Neurosci 2002; 16:105-18. [PMID: 12153535 DOI: 10.1046/j.1460-9568.2002.02077.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Following axotomy, cerebellar Purkinje cells (PCs) do not elongate their axons, even in a favourable environment, and are resistant to death. They have no constitutive presence of common growth-associated proteins, such as GAP-43 and c-Jun. Previous experiments show that injured transgenic PCs overexpressing GAP-43 exhibit a profuse sprouting along the axon and at its severed end. Nevertheless, the lesioned axons are unable to regenerate either spontaneously or into growth-permissive environments. In addition, a considerable number of GAP-43 transgenic PCs degenerate after injury. c-Jun is an inducible transcription factor expressed in axotomized central neurons and regenerating peripheral neurons. It also contributes to programmed cell death during development. To test whether c-Jun could modify the response of PCs to axotomy or enhance the growth/death phenomena of GAP-43 Purkinje neurons, we generated transgenic mice overexpressing c-Jun in PCs. However, c-Jun upregulation did not affect the adult intact phenotype of these neurons and their regenerative and survival capabilities after axotomy. Also in the cross-bred GAP-43/c-Jun mice, c-Jun did not modify the response of GAP-43 PCs to axotomy. By contrast, in organotypic cultures of cerebellum taken from 9-day-old-pups, the survival capabilities of PCs overexpressing c-Jun decreased, in association with a consistent c-Jun phosphorylation. On the whole our data show that c-Jun alone is unable to trigger regenerative or degenerative phenomena in PCs and suggest that the cellular action of this early gene in developing and mature neurons strongly depends on interplaying intracellular signals.
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Affiliation(s)
- Daniela Carulli
- Rita Levi-Montalcini Centre for Brain Repair, Department of Neuroscience, University of Turin, C. Raffaello 30, 10125 Turin, Italy.
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22
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Labombarda F, Gonzalez SL, Gonzalez DMC, Guennoun R, Schumacher M, de Nicola AF. Cellular basis for progesterone neuroprotection in the injured spinal cord. J Neurotrauma 2002; 19:343-55. [PMID: 11939502 DOI: 10.1089/089771502753594918] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Progesterone (PROG) exerts beneficial and neuroprotective effects in the injured central and peripheral nervous system. In the present work, we examine PROG effects on three measures of neuronal function under negative regulation (choline acetyltransferase [ChAT] and Na,K-ATPase) or stimulated (growth-associated protein [GAP-43]) after acute spinal cord transection injury in rats. As expected, spinal cord injury reduced ChAT immunostaining intensity of ventral horn neurons. A 3-day course of intensive PROG treatment of transected rats restored ChAT immunoreactivity, as assessed by frequency histograms that recorded shifts from predominantly light neuronal staining to medium, dark or intense staining typical of control rats. Transection also reduced the expression of the mRNA for the alpha3 catalytic and beta1 regulatory subunits of neuronal Na,K-ATPase, whereas PROG treatment restored both subunit mRNA to normal levels. Additionally, the upregulation observed for GAP-43 mRNA in ventral horn neurons in spinal cord-transected rats, was further enhanced by PROG administration. In no case did PROG modify ChAT immunoreactivity, Na,K-ATPase subunit mRNA or GAP-43 mRNA in control, sham-operated rats. Further, the PROG-mediated effects on these three markers were observed in large, presumably Lamina IX motoneurons, as well as in smaller neurons measuring approximately <500 micro2. Overall, the stimulatory effects of PROG on ChAT appears to replenish acetylcholine, with its stimulatory effects on Na,K-ATPase seems capable of restoring membrane potential, ion transport and nutrient uptake. PROG effects on GAP-43 also appear to accelerate reparative responses to injury. As the cellular basis for PROG neuroprotection becomes better understood it may prove of therapeutic benefit to spinal cord injury patients.
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Affiliation(s)
- Florencia Labombarda
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, and Department of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Argentina
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23
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Flügel A, Hager G, Horvat A, Spitzer C, Singer GM, Graeber MB, Kreutzberg GW, Schwaiger FW. Neuronal MCP-1 expression in response to remote nerve injury. J Cereb Blood Flow Metab 2001; 21:69-76. [PMID: 11149670 DOI: 10.1097/00004647-200101000-00009] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Direct injury of the brain is followed by inflammatory responses regulated by cytokines and chemoattractants secreted from resident glia and invading cells of the peripheral immune system. In contrast, after remote lesion of the central nervous system, exemplified here by peripheral transection or crush of the facial and hypoglossal nerve, the locally observed inflammatory activation is most likely triggered by the damaged cells themselves, that is, the injured neurons. The authors investigated the expression of the chemoattractants monocyte chemoattractant protein MCP-1, regulation on activation normal T-cell expressed and secreted (RANTES), and interferon-gamma inducible protein IP10 after peripheral nerve lesion of the facial and hypoglossal nuclei. In situ hybridization and immunohistochemistry revealed an induction of neuronal MCP-1 expression within 6 hours postoperation, reaching a peak at 3 days and remaining up-regulated for up to 6 weeks. MCP-1 expression was almost exclusively confined to neurons but was also present on a few scattered glial cells. The authors found no alterations in the level of expression and cellular distribution of RANTES or IP10, which were both confined to neurons. Protein expression of the MCP-1 receptor CCR2 did not change. MCP-1, expressed by astrocytes and activated microglia, has been shown to be crucial for monocytic, or T-cell chemoattraction, or both. Accordingly, expression of MCP-1 by neurons and its corresponding receptor in microglia suggests that this chemokine is involved in neuron and microglia interaction.
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Affiliation(s)
- A Flügel
- Department of Neuroimmunology, Max-Planck-Institute of Neurobiology, Martinsried, Germany
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24
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Soares HD, Chen SC, Morgan JI. Differential and prolonged expression of Fos-lacZ and Jun-lacZ in neurons, glia, and muscle following sciatic nerve damage. Exp Neurol 2001; 167:1-14. [PMID: 11161588 DOI: 10.1006/exnr.2000.7558] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Fos-lacZ and Jun-lacZ transgenic mice were used to assess the involvement of immediate-early genes in the axotomy-transcription coupling pathway triggered by sciatic nerve injury in neonates and adults. Nerve transection transiently induced Fos-lacZ in degenerating (neonatal) and regenerating (adult) motor, but not sensory, neurons. In contrast, Jun-lacZ was persistently up-regulated in both axotomized motor and sensory neurons in neonates and adults. Thus, expression of these genes did not predict neuronal death or survival. As Jun-lacZ was induced in some undamaged sensory neurons, this gene can be regulated by direct (axotomy) and indirect (transcellular) mechanisms. Indirect mechanisms also mediate expression of both genes in denervated muscle, Schwann cells in the distal and proximal stumps, and satellite cells in the DRG following axotomy. Thus, either these genes may regulate distinct sets of target genes in different cell types or they may subserve a single mechanism that is common to many cell types.
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MESH Headings
- Animals
- Axotomy
- Cell Survival/genetics
- Ganglia, Spinal/cytology
- Ganglia, Spinal/metabolism
- Gene Expression
- Genes, Reporter/genetics
- Mice
- Mice, Transgenic
- Motor Neurons/cytology
- Motor Neurons/metabolism
- Muscle, Skeletal/cytology
- Muscle, Skeletal/innervation
- Muscle, Skeletal/metabolism
- Nerve Regeneration/physiology
- Neuroglia/cytology
- Neuroglia/metabolism
- Neurons, Afferent/cytology
- Neurons, Afferent/metabolism
- Proto-Oncogene Proteins c-fos/biosynthesis
- Proto-Oncogene Proteins c-fos/genetics
- Proto-Oncogene Proteins c-jun/biosynthesis
- Proto-Oncogene Proteins c-jun/genetics
- RNA, Messenger/biosynthesis
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/genetics
- Schwann Cells/cytology
- Schwann Cells/metabolism
- Sciatic Nerve/cytology
- Sciatic Nerve/physiology
- Transgenes/genetics
- beta-Galactosidase/biosynthesis
- beta-Galactosidase/genetics
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Affiliation(s)
- H D Soares
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 332 North Lauderdale Street, Memphis, Tennessee 38105, USA
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25
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Schwaiger FW, Hager G, Schmitt AB, Horvat A, Hager G, Streif R, Spitzer C, Gamal S, Breuer S, Brook GA, Nacimiento W, Kreutzberg GW. Peripheral but not central axotomy induces changes in Janus kinases (JAK) and signal transducers and activators of transcription (STAT). Eur J Neurosci 2000; 12:1165-76. [PMID: 10762348 DOI: 10.1046/j.1460-9568.2000.00005.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nerve injury leads to the release of a number of cytokines which have been shown to play an important role in cellular activation after peripheral nerve injury. The members of the signal transducer and activator of transcription (STAT) gene family are the main mediators in the signal transduction pathway of cytokines. After phosphorylation, STAT proteins are transported into the nucleus and exhibit transcriptional activity. Following axotomy in rat regenerating facial and hypoglossal neurons, a transient increase of mRNA for JAK2, JAK3, STAT1, STAT3 and STAT5 was detected using in situ hybridization and semi-quantitative polymerase chain reaction (PCR). Of the investigated STAT molecules, only STAT3 protein was significantly increased. In addition, activation of STAT3 by phosphorylation on position Tyr705 and enhanced nuclear translocation was found within 3 h in neurons and after 1 day in astrocytes. Unexpectedly, STAT3 tyrosine phosphorylation was obvious for more than 3 months. In contrast, none of these changes was found in response to axotomy of non-regenerating Clarke's nucleus neurons, although all the investigated models express c-Jun and growth-associated protein-43 (GAP-43) in response to axonal injury. Increased expression of Janus kinase (JAK) and STAT molecules after peripheral nerve transection suggests changes in the responsiveness of the neurons to signalling molecules. STAT3 as a transcription factor, which is expressed early and is activated persistently until the time of reinnervation, might be involved in the switch from the physiological gene expression to an 'alternative program' activated only after peripheral nerve injury.
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Affiliation(s)
- F W Schwaiger
- Department of Neuromorphology, Max-Planck Institute of Neurobiology, D-82152 Martinsried, Germany.
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