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Kawasaki T, Fujimori KE, Imada J, Yuba S. Analysis of medaka GAP43 gene promoter activity in transgenic lines. Gene 2023:147590. [PMID: 37364694 DOI: 10.1016/j.gene.2023.147590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/03/2023] [Accepted: 06/21/2023] [Indexed: 06/28/2023]
Abstract
We produced transgenic medaka fish lines that mimicked the expression of the GAP43 gene. Fish lines with the proximal 2-kilobase (kb) 5'-untranslated region (UTR) as the expression promoter specifically expressed enhanced green fluorescent protein (EGFP) in neural tissues, such as the brain, spinal cord, and peripheral nerves, and its expression decreased with growth, but persisted until adulthood. A functional analysis of the promoter using partially deleted UTRs revealed that functions related to neural tissue-specific promoter activity were widely distributed in the region upstream of the proximal 400-b. Furthermore, the distal half of the 2-kb UTR contributed to expression throughout the brain, while the region 400-b upstream of the proximal 600-b was strongly associated with expression in specific areas, such as the telencephalon. In addition, a region from 957 to 557 b upstream of the translation initiation site was important for the long-term maintenance of promoter activity into adulthood. Among the transcription factors with recognition sequences in this region, Sp1 and CREB1 have been suggested to play important roles in the GAP43 promoter expression characteristics, such as strong expression in the telencephalon and long-term maintenance of expression.
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Affiliation(s)
- Takashi Kawasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, 563-8577, Japan
| | - Kazuhiro E Fujimori
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi, Tsukuba, Ibaraki 305-0046, Japan.
| | - Junko Imada
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, 563-8577, Japan
| | - Shunsuke Yuba
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, 563-8577, Japan.
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Bakri AH, Hassan MH, Ahmed AEA, Alotaibi G, Halim PR, Abdallah AAM, Rashwan NI. Serum Levels of Growth-Associated Protein-43 and Neurotrophin-3 in Childhood Epilepsy and Their Relation to Zinc Levels. Biol Trace Elem Res 2023; 201:689-697. [PMID: 35349008 PMCID: PMC9849170 DOI: 10.1007/s12011-022-03213-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/19/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND Epilepsy is one of the most common neurological disorders, and it places a significant economic strain on the healthcare system around the world. Although the exact mechanism of epilepsy has yet to be illustrated, various pathogenic cascades involving neurotransmitters and trace elements have been reported. We aimed to investigate the serum levels of growth-associated protein-43 (GAP-43) and neurotrophin-3 (NT-3) among cohort of Egyptian children with epilepsy and correlate these biomarkers with their zinc levels. METHODS This case-control study included 50 pediatric patients with epilepsy who were comparable with 50 controls. Neurological assessment and electroencephalogram (EEG) were done to all included children. Biochemical measurements of serum GAP-43 and NT-3 using enzyme linked immunosorbent assays (ELISA), and total antioxidant capacity (TAC) and zinc using colorimetric assays, were performed to all participants. RESULTS There was significantly frequent positive parental consanguinity among cases with significantly frequent generalized onset seizures (94%) than simple partial seizure (6%). There were significantly lower serum GAP-43 and zinc levels with significantly higher TAC among cases vs. the controls, p˂0.05 for all. There was no significant difference in the serum levels of NT-3 among epileptic children vs. the controls, p = 0.269. Serum Zn was positively correlated with GAP-43 level among epileptic children (r = 0.381, p = 0.006). Serum GAP-43 in diagnosing childhood epilepsy at cut-off point ≤ 0.6 ng/mL showed 78% sensitivity, 62% specificity, positive predictive value (PPV) = 50.6%, negative predictive value (NPP) = 84.9% with AUC = 0.574. CONCLUSION GAP-43 can be considered a sensitive good negative biomarker in childhood epilepsy which correlated positively with the zinc status.
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Affiliation(s)
- Ali Helmi Bakri
- Department of Pediatrics, Faculty of Medicine, South Valley University, Qena, Egypt
| | - Mohammed H Hassan
- Department of Medical Biochemistry, Faculty of Medicine, South Valley University, Qena, 83523, Egypt.
| | - Ahmed El-Abd Ahmed
- Department of Pediatrics, Faculty of Medicine, South Valley University, Qena, Egypt
| | - Ghallab Alotaibi
- Department of Pharmaceutical Sciences, College of Pharmacy, Shaqra University, Al-Dawadmi Campus, Shaqra, Saudi Arabia
| | - Pola Rafat Halim
- Department of Pediatrics, Faculty of Medicine, South Valley University, Qena, Egypt
| | | | - Nagwan I Rashwan
- Department of Pediatrics, Faculty of Medicine, South Valley University, Qena, Egypt
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Carrero-Rojas G, Calvo PM, Lischka T, Streicher J, de la Cruz RR, Pastor AM, Blumer R. Eye Movements But Not Vision Drive the Development of Palisade Endings. Invest Ophthalmol Vis Sci 2022; 63:15. [PMID: 36255363 PMCID: PMC9587472 DOI: 10.1167/iovs.63.11.15] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To test whether visual experience and/or eye movements drive the postnatal development of palisade endings in extraocular muscles. Methods In three newborn cats, the right eye was covered until 30 days from postnatal (P) day 7 (before opening their eyes), and in three cats both eyes were covered until 45 days, also from P7. To block eye movements, another seven cats received a retrobulbar injection of botulinum neurotoxin A (BoNT-A) into the left orbit at birth and survived for 45 days (three cats) and 95 days (four cats). The distal third of the rectus muscles containing the palisade endings was used for whole-mount preparation and triple-fluorescence labeling with anti-neurofilament along with (1) anti-synaptophysin and phalloidin or (2) anti-growth associated protein 43 (GAP43) and phalloidin. Immunolabeled specimens were analyzed in the confocal laser scanning microscope. Results After unilateral and bilateral dark rearing, palisade endings were qualitatively and quantitatively equal to those from age-matched controls. After BoNT-A induced eye immobilization for 45 or 95 days, palisade endings were absent in the superior rectus and lateral rectus muscles and only present in the inferior rectus and medial rectus muscle. These BoNT-A-treated palisade endings were rudimentary and reduced in number, and the expression of the neuronal developmental protein GAP43 was significantly reduced. Conclusions This study demonstrates that eye immobilization, but not visual deprivation, affects palisade ending development. Palisade endings develop in the first month of life, and the present findings indicate that, during this time window, palisade endings are prone to oculomotor perturbations.
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Affiliation(s)
| | - Paula M Calvo
- Departament of Physiology, Faculty of Biology, University of Seville, Seville, Spain
| | - Thomas Lischka
- Department of Ophthalmology, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Johannes Streicher
- Department of Anatomy and Biomechanics, Division of Anatomy and Developmental Biology, Karl Landsteiner University of Health Science, Krems an der Donau, Austria
| | - Rosa R de la Cruz
- Departament of Physiology, Faculty of Biology, University of Seville, Seville, Spain
| | - Angel M Pastor
- Departament of Physiology, Faculty of Biology, University of Seville, Seville, Spain
| | - Roland Blumer
- Center of Anatomy and Cell Biology, Medical University Vienna, Vienna, Austria
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Tumor innervation is triggered by endoplasmic reticulum stress. Oncogene 2022; 41:586-599. [PMID: 34785777 DOI: 10.1038/s41388-021-02108-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/24/2021] [Accepted: 10/27/2021] [Indexed: 11/09/2022]
Abstract
Nerve infiltration in the tumor microenvironment is emerging as a promoter of cancer progression that could be targeted in therapies, but the mechanisms initiating tumor innervation remain to be elucidated. Here we report that endoplasmic reticulum (ER) stress in cancer cells is transmitted to neuronal cells, resulting in neurite outgrowth and tumor innervation. In vitro, the induction of ER stress in various human cancer cells resulted in the synthesis and release of the precursor for brain-derived neurotrophic factor (proBDNF) through a mechanism dependent on the transcription factor X-box binding protein 1 (XBP1). Cancer cell-released proBDNF was found to mediate the transmission of ER stress to neurons, resulting in the stimulation of neurite outgrowth. Next-generation sequencing indicated the increased expression of the Egl-9 family hypoxia inducible factor 3 (EGLN3) that was mediated by c-MYC and necessary to neurite outgrowth induced by proBDNF. In orthotopic tumor xenograft, ER stress stimulated XBP1 and proBDNF expression as well as tumor innervation. Anti-proBDNF antibody inhibited both tumor innervation and cancer progression induced by ER stress. Interestingly, the chemotherapeutic drug 5-Fluorouracil (5-FU) was found to induce ER stress and tumor innervation, and this effect was inhibited by anti-proBDNF antibody. Finally, in human tumors, cancer tissues with nerve infiltration expressed high XBP1 and proBDNF while EGLN3 was upregulated in infiltrated nerves. This study reveals that ER stress participates in tumor innervation through the release of proBDNF and that targeting this pathway could be used in future therapies.
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Sallam A, Sudha T, Darwish NHE, Eghotny S, E-Dief A, Hassaan PS, Mousa SA. In vitro differentiation of human bone marrow stromal cells into neural precursor cells using small molecules. J Neurosci Methods 2021; 363:109340. [PMID: 34461154 DOI: 10.1016/j.jneumeth.2021.109340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/29/2021] [Accepted: 08/25/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND Neurogenic differentiation of human marrow stromal stem cells (hMSCs) into neural precursor cells (NPCs) offers new hope in many neurological diseases. Stromal cells can be differentiated into NPCs using small molecules acting as chemical inducers. The aim of this study is to formulate an efficient, direct, fast and safe protocol to differentiate hMSCs into NPCs using different inducers: b-mercaptoethanol (BME), triiodothyronine (T3), and curcumin (CUR). NEW METHOD: hMSCs were subjected to either 1 mM BME, 0.5 µM T3, or 5 µM CUR. Neurogenic differentiation was determined by assessing the protein expression of PAX6, SOX2, DLX2, and GAP-43 with flow cytometry and immunofluorescence, along with Nissl staining of differentiated cells. RESULTS AND COMPARISON WITH EXISTING METHOD It was revealed that T3 and CUR are 70-80% better than BME in terms of efficiency and safety, and surprisingly BME was a good promoting factor for cell preconditioning with limited effects on neural trans-differentiation related to its toxic effects on cell viability. CONCLUSION Reprogramming of bone marrow stromal cells into neural cells gives hope for treating different neurological disorders. Our study shows that T3 and CUR were effective in generation of NPCs from hMSCs with preservation of cell viability. BME was a good promoting factor for cell preconditioning with limited effects on neural transdifferentiation related to its toxic effects on cell viability.
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Affiliation(s)
- Abeer Sallam
- Department of Medical Physiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt; Center of Excellence for Research in Regenerative Medicine and its Applications, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Thangirala Sudha
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY, USA
| | - Noureldien H E Darwish
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY, USA; Hematology Unit, Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Samar Eghotny
- Department of Medical Physiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Abeer E-Dief
- Department of Medical Physiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Passainte S Hassaan
- Department of Medical Physiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Shaker A Mousa
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY, USA.
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Chung D, Shum A, Caraveo G. GAP-43 and BASP1 in Axon Regeneration: Implications for the Treatment of Neurodegenerative Diseases. Front Cell Dev Biol 2020; 8:567537. [PMID: 33015061 PMCID: PMC7494789 DOI: 10.3389/fcell.2020.567537] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/14/2020] [Indexed: 01/06/2023] Open
Abstract
Growth-associated protein-43 (GAP-43) and brain acid-soluble protein 1 (BASP1) regulate actin dynamics and presynaptic vesicle cycling at axon terminals, thereby facilitating axonal growth, regeneration, and plasticity. These functions highly depend on changes in GAP-43 and BASP1 expression levels and post-translational modifications such as phosphorylation. Interestingly, examinations of GAP-43 and BASP1 in neurodegenerative diseases reveal alterations in their expression and phosphorylation profiles. This review provides an overview of the structural properties, regulations, and functions of GAP-43 and BASP1, highlighting their involvement in neural injury response and regeneration. By discussing GAP-43 and BASP1 in the context of neurodegenerative diseases, we also explore the therapeutic potential of modulating their activities to compensate for neuron loss in neurodegenerative diseases.
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Affiliation(s)
- Daayun Chung
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Andrew Shum
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Gabriela Caraveo
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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Holahan MR. A Shift from a Pivotal to Supporting Role for the Growth-Associated Protein (GAP-43) in the Coordination of Axonal Structural and Functional Plasticity. Front Cell Neurosci 2017; 11:266. [PMID: 28912688 PMCID: PMC5583208 DOI: 10.3389/fncel.2017.00266] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/18/2017] [Indexed: 11/14/2022] Open
Abstract
In a number of animal species, the growth-associated protein (GAP), GAP-43 (aka: F1, neuromodulin, B-50, G50, pp46), has been implicated in the regulation of presynaptic vesicular function and axonal growth and plasticity via its own biochemical properties and interactions with a number of other presynaptic proteins. Changes in the expression of GAP-43 mRNA or distribution of the protein coincide with axonal outgrowth as a consequence of neuronal damage and presynaptic rearrangement that would occur following instances of elevated patterned neural activity including memory formation and development. While functional enhancement in GAP-43 mRNA and/or protein activity has historically been hypothesized as a central mediator of axonal neuroplastic and regenerative responses in the central nervous system, it does not appear to be the crucial substrate sufficient for driving these responses. This review explores the historical discovery of GAP-43 (and associated monikers), its transcriptional, post-transcriptional and post-translational regulation and current understanding of protein interactions and regulation with respect to its role in axonal function. While GAP-43 itself appears to have moved from a pivotal to a supporting factor, there is no doubt that investigations into its functions have provided a clearer understanding of the biochemical underpinnings of axonal plasticity.
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Jesky R, Chen H. The neuritogenic and neuroprotective potential of senegenin against Aβ-induced neurotoxicity in PC 12 cells. Altern Ther Health Med 2016; 16:26. [PMID: 26803813 PMCID: PMC4724108 DOI: 10.1186/s12906-016-1006-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 01/20/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Improved therapeutics aimed at ameliorating the devastating effects of neurodegenerative diseases, such as Alzheimer's disease (AD), are pertinent to help attenuate their growing prevalence worldwide. One promising avenue for such therapeutics lies in botanical medicines that have been efficaciously employed in the likes of traditional medicine doctrines for millennium. Integral to this approach is the necessity of neuritogenesis and/or neuroprotection to counterbalance the deleterious effects of amyloid-β (Aβ) proteins. Senegenin, a principle saponin of Polygala tenuifolia Willd., which has empirically shown to improve cognition and intelligence, was chosen to evaluate its cytoprotective potential and possible neuritogenic and neuroprotective effects. METHODS The purpose of the present study was then to analyze morphological changes in neurite development and altered protein expression of two proteins requisite to neuritogenesis, growth associated protein 43 (Gap-43) and microtubule-associated protein 2 (MAP2) in PC 12 cells. Neuritogenic analysis was conducted with immunofluorescence after incubation with Aβ (25-35) peptide, and to deduce information on cell viability and mitochondrial functionality MTT (3,(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) was employed. RESULTS This study found that cells pre-incubated with senegenin for 24 h (40 μg and 20 μg/ml) before introducing Aβ attenuated Aβ-cytotoxicity, and significantly increased cell viability by 23 % and 34 % (P < 0.001), respectively. In neurite outgrowth experiments, Aβ was compared to NGF positive control and senegenin treated groups which showed a drastic decrease in the quantity, average length and maximum length of neurites (P < 0.001). At concentrations of 1 μg/ml (P < 0.01) and 5 μg/ml (P < 0.05) senegenin triggered neuritogenesis with significant increases in total neurite number, average length and maximum length. This was additionally shown through the augmented expression of MAP2 and Gap-43. CONCLUSIONS These results suggest that senegenin possesses cytoprotective properties, can moderate neurite outgrowth and augment MAP2 and Gap-43, thus suggesting a potential therapeutic value for Polygala tenuifolia in neurodegenerative disorders.
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Gauthier-Kemper A, Igaev M, Sündermann F, Janning D, Brühmann J, Moschner K, Reyher HJ, Junge W, Glebov K, Walter J, Bakota L, Brandt R. Interplay between phosphorylation and palmitoylation mediates plasma membrane targeting and sorting of GAP43. Mol Biol Cell 2014; 25:3284-99. [PMID: 25165142 PMCID: PMC4214776 DOI: 10.1091/mbc.e13-12-0737] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
A combination of biochemical, genetic, and imaging approaches is used to show that phosphorylation and lipidation exhibit a complex interplay in sorting of GAP43. Palmitoylation tags GAP43 for global sorting by inducing piggybacking on exocytic vesicles, whereas phosphorylation locally regulates plasma membrane targeting of palmitoylated GAP43. Phosphorylation and lipidation provide posttranslational mechanisms that contribute to the distribution of cytosolic proteins in growing nerve cells. The growth-associated protein GAP43 is susceptible to both phosphorylation and S-palmitoylation and is enriched in the tips of extending neurites. However, how phosphorylation and lipidation interplay to mediate sorting of GAP43 is unclear. Using a combination of biochemical, genetic, and imaging approaches, we show that palmitoylation is required for membrane association and that phosphorylation at Ser-41 directs palmitoylated GAP43 to the plasma membrane. Plasma membrane association decreased the diffusion constant fourfold in neuritic shafts. Sorting to the neuritic tip required palmitoylation and active transport and was increased by phosphorylation-mediated plasma membrane interaction. Vesicle tracking revealed transient association of a fraction of GAP43 with exocytic vesicles and motion at a fast axonal transport rate. Simulations confirmed that a combination of diffusion, dynamic plasma membrane interaction and active transport of a small fraction of GAP43 suffices for efficient sorting to growth cones. Our data demonstrate a complex interplay between phosphorylation and lipidation in mediating the localization of GAP43 in neuronal cells. Palmitoylation tags GAP43 for global sorting by piggybacking on exocytic vesicles, whereas phosphorylation locally regulates protein mobility and plasma membrane targeting of palmitoylated GAP43.
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Affiliation(s)
| | - Maxim Igaev
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Frederik Sündermann
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Dennis Janning
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Jörg Brühmann
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Katharina Moschner
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Hans-Jürgen Reyher
- Department of Experimental Physics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Wolfgang Junge
- Department of Biophysics, University of Osnabrück, 49076 Osnabrück, Germany
| | | | - Jochen Walter
- Department of Neurology, University of Bonn, 53127 Bonn, Germany
| | - Lidia Bakota
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany
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Berg A, Zelano J, Stephan A, Thams S, Barres BA, Pekny M, Pekna M, Cullheim S. Reduced removal of synaptic terminals from axotomized spinal motoneurons in the absence of complement C3. Exp Neurol 2012; 237:8-17. [PMID: 22721768 DOI: 10.1016/j.expneurol.2012.06.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/05/2012] [Accepted: 06/09/2012] [Indexed: 11/25/2022]
Abstract
Complement proteins C1q and C3 play a critical role in synaptic elimination during development. Axotomy of spinal motoneurons triggers removal of synaptic terminals from the cell surface of motoneurons by largely unknown mechanisms. We therefore hypothesized that the complement system is involved also in synaptic stripping of injured motoneurons. In the sciatic motor pool of wild type (WT) mice, the immunoreactivity (IR) for both C1q and C3 was increased after sciatic nerve transection (SNT). Mice deficient in C3 (C3(-/-)) showed a reduced loss of synaptic terminals from injured motoneurons at one week after SNT, as assessed by immunoreactivity for synaptic markers and electron microscopy. In particular, the removal of putative inhibitory terminals, immunopositive for vesicular inhibitory amino acid transporter (VIAAT) and ultrastructurally identified as type F synapses, was reduced in C3(-/-) mice. In contrast, lesion-induced removal of nerve terminals in C1q(-/-) mice appeared similar to WT mice. Growth associated protein (GAP)-43 mRNA expression in lesioned motoneurons increased much more in C3(-/-) compared to WT mice after SNT. After sciatic nerve crush (SNC), the C3(-/-) mice showed a faster functional recovery, assessed as grip strength, compared to WT mice. No differences were detected regarding nerve inflammation at the site of injury or pattern of muscle reinnervation. These data indicate that a non-classical pathway of complement activation is involved in axotomy-induced adult synapse removal, and that its inhibition promotes functional recovery.
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Affiliation(s)
- Alexander Berg
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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Olsson B, Zetterberg H, Hampel H, Blennow K. Biomarker-based dissection of neurodegenerative diseases. Prog Neurobiol 2011; 95:520-34. [PMID: 21524681 DOI: 10.1016/j.pneurobio.2011.04.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 04/06/2011] [Accepted: 04/10/2011] [Indexed: 12/12/2022]
Abstract
The diagnosis of neurodegenerative diseases within neurology and psychiatry are hampered by the difficulty in getting biopsies and thereby validating the diagnosis by pathological findings. Biomarkers for other types of disease have been readily adopted into the clinical practice where for instance troponins are standard tests when myocardial infarction is suspected. However, the use of biomarkers for neurodegeneration has not been fully incorporated into the clinical routine. With the development of cerebrospinal fluid (CSF) biomarkers that reflect pathological events within the central nervous system (CNS), important clinical diagnostic tools are becoming available. This review summarizes the most promising biomarker candidates that may be used to monitor different types of neurodegeneration and protein inclusions, as well as different types of metabolic changes, in living patients in relation to the clinical phenotype and disease progression over time. Our aim is to provide the reader with an updated lexicon on currently available biomarker candidates, how far they have come in development and how well they reflect pathogenic processes in different neurodegenerative diseases. Biomarkers for specific pathogenetic processes would also be valuable tools both to study disease pathogenesis directly in patients and to identify and monitor the effect of novel treatment strategies.
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Affiliation(s)
- Bob Olsson
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, S-431 80 Mölndal, Sweden.
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Fong BA, Wood DW. Expression and purification of ELP-intein-tagged target proteins in high cell density E. coli fermentation. Microb Cell Fact 2010; 9:77. [PMID: 20959011 PMCID: PMC2978133 DOI: 10.1186/1475-2859-9-77] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 10/19/2010] [Indexed: 11/20/2022] Open
Abstract
Background Elastin-like polypeptides (ELPs) are useful tools that can be used to non-chromatographically purify proteins. When paired with self-cleaving inteins, they can be used as economical self-cleaving purification tags. However, ELPs and ELP-tagged target proteins have been traditionally expressed using highly enriched media in shake flask cultures, which are generally not amenable to scale-up. Results In this work, we describe the high cell-density expression of self-cleaving ELP-tagged targets in a supplemented minimal medium at a 2.5 liter fermentation scale, with increased yields and purity compared to traditional shake flask cultures. This demonstration of ELP expression in supplemented minimal media is juxtaposed to previous expression of ELP tags in extract-based rich media. We also describe several sets of fed-batch conditions and their impact on ELP expression and growth medium cost. Conclusions By using fed batch E. coli fermentation at high cell density, ELP-intein-tagged proteins can be expressed and purified at high yield with low cost. Further, the impact of media components and fermentation design can significantly impact the overall process cost, particularly at large scale. This work thus demonstrates an important advances in the scale up of self-cleaving ELP tag-mediated processes.
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Affiliation(s)
- Baley A Fong
- Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544, USA
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Netrin G-2 ligand mRNA is downregulated in spinal motoneurons after sciatic nerve lesion. Neuroreport 2010; 21:782-5. [DOI: 10.1097/wnr.0b013e32833cadd8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nagamoto-Combs K, Morecraft RJ, Darling WG, Combs CK. Long-term gliosis and molecular changes in the cervical spinal cord of the rhesus monkey after traumatic brain injury. J Neurotrauma 2010; 27:565-85. [PMID: 20030560 DOI: 10.1089/neu.2009.0966] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recovery of fine motor skills after traumatic brain injury (TBI) is variable, with some patients showing progressive improvements over time while others show poor recovery. We therefore studied possible cellular mechanisms accompanying the recovery process in a non-human primate model system, in which the lateral frontal motor cortex areas controlling the preferred upper limb were unilaterally lesioned, and the animals eventually regained fine hand motor function. Immunohistochemical staining of the cervical spinal cord, the site of compensatory sprouting and degeneration of corticospinal axons, showed profound increases in immunoreactivities for major histocompatibility complex class II molecule (MHC-II) and extracellular signal-regulated kinases (ERK1/2) up to 12 months post lesion, particularly within the lateral corticospinal tract (LCST). Double immunostaining demonstrated that phosphorylated ERK1/2 colocalized within the MCH-II + microglia, suggesting a trophic role of long-term microglia activation after TBI at the site of compensatory sprouting. Active sprouting was observed in the LCST as well as in the spinal gray matter of the lesioned animals, as illustrated by increases in growth associated protein 43. Upregulation of Nogo receptor and glutamate transporter expression was also observed in this region after TBI, suggesting possible mechanisms for controlling aberrant sprouting and/or synaptic formation en route and interstitial glutamate concentration changes at the site of axon degeneration, respectively. Taken together, these changes in the non-human primate spinal cord support a long-term trophic/tropic role for reactive microglia, in particular, during functional and structural recovery after TBI.
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Affiliation(s)
- Kumi Nagamoto-Combs
- Department of Anatomy and Cell Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58202, USA
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15
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Zelano J, Berg A, Thams S, Hailer NP, Cullheim S. SynCAM1 expression correlates with restoration of central synapses on spinal motoneurons after two different models of peripheral nerve injury. J Comp Neurol 2010; 517:670-82. [PMID: 19827159 DOI: 10.1002/cne.22186] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SynCAM1 and neuroligins (NLGs) are adhesion molecules that govern synapse formation in vitro. In vivo, the molecules are expressed during synaptogenesis, and altered NLG function is linked to synapse dysfunction in autism. Less is known about SynCAM1 and NLGs in adult synapse remodeling. CNS synapse elimination occurs after peripheral nerve injury, which causes a transient decrease in synapse number on spinal motoneurons. Here we have studied the expression of SynCAM1 and NLGs in relation to changes in synaptic covering on spinal motoneurons. We performed sciatic nerve transection (SNT) or crush (SNC), axotomy models that result in poor or good conditions for axon regeneration, respectively. The two lesions resulted in similar synapse elimination and in poor (SNT) and good (SNC) return of synapses after 70 days. Functional recovery was good after SNC but absent after SNT. SynCAM1 mRNA decreased after 14 days in both models and was restored 70 days after SNC, but not after SNT. NLG2 and -3 mRNAs decreased to a smaller degree after SNC than after SNT. Synaptophysin immunoreactivity correlated with SynCAM1 mRNA 70 days after SNT and NLG2 mRNA 70 days after SNC. Surprisingly, an inverse correlation was seen between NLG3 mRNA and Vglut2, a marker for excitatory synapses, 70 days after SNT. We conclude that 1) SynCAM1 mRNA levels seem to reflect the loss and restoration of synapses on motoneurons, 2) down-regulation of NLGs is not a prerequisite for synapse elimination, and 3) expression of SynCAM1 and NLGs is regulated by different mechanisms during regeneration.
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Affiliation(s)
- Johan Zelano
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
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16
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Jutapakdeegul N, Afadlal S, Polaboon N, Phansuwan‐Pujito P, Govitrapong P. Repeated restraint stress and corticosterone injections during late pregnancy alter GAP‐43 expression in the hippocampus and prefrontal cortex of rat pups. Int J Dev Neurosci 2009; 28:83-90. [DOI: 10.1016/j.ijdevneu.2009.09.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 09/01/2009] [Accepted: 09/15/2009] [Indexed: 11/26/2022] Open
Affiliation(s)
- Nuanchan Jutapakdeegul
- Neuro‐Behavioral Biology CenterInstitute of Molecular BiosciencesMahidol UniversityNakornpathom73170Thailand
| | - Szeifoul Afadlal
- Neuro‐Behavioral Biology CenterInstitute of Molecular BiosciencesMahidol UniversityNakornpathom73170Thailand
| | - Nongnuch Polaboon
- Faculty of Allied Health SciencesChristian UniversityNakornpathom73000Thailand
| | | | - Piyarat Govitrapong
- Neuro‐Behavioral Biology CenterInstitute of Molecular BiosciencesMahidol UniversityNakornpathom73170Thailand
- Center for NeuroscienceFaculty of ScienceMahidol UniversityBangkokThailand
- Department of Pharmacology, Faculty of ScienceMahidol UniversityBangkokThailand
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17
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Jiang Y, Guo C, Fishel ML, Wang ZY, Vasko MR, Kelley MR. Role of APE1 in differentiated neuroblastoma SH-SY5Y cells in response to oxidative stress: use of APE1 small molecule inhibitors to delineate APE1 functions. DNA Repair (Amst) 2009; 8:1273-82. [PMID: 19726241 DOI: 10.1016/j.dnarep.2009.08.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 07/20/2009] [Accepted: 08/10/2009] [Indexed: 11/25/2022]
Abstract
Oxidative DNA damage has been implicated in a number of central nervous system pathologies. The base excision repair (BER) pathway is one of the most important cellular protection mechanisms that respond to oxidative DNA damage. Human apurinic (apyrimidinic) endonuclease/redox effector factor (APE1/Ref-1 or APE1) is an essential enzyme in the BER pathway and is expressed in both mitotic and post-mitotic cells in humans. In neurons, a reduction of APE1 expression increases chemotherapy-induced cytotoxicity, while overexpression of APE1 protects cells against the cytotoxicity. However, given the multiple functions of APE1, knockdown of total APE1 is not completely informative of whether it is the redox or DNA repair activity, or interactions with other proteins. Therefore, the use of selective small molecules that can block each function independent of the other is of great benefit in ascertaining APE1 function in post-mitotic cells. In this study, we chose differentiated SH-SY5Y cells as our post-mitotic cell line model to investigate whether a drug-induced decrease in APE1 DNA repair or redox activity contributes to the growth and survival of post-mitotic cells under oxidative DNA damaging conditions. Here, we demonstrate that overexpression of WT-APE1 or C65-APE1 (repair competent) results in significant increase in cell viability after exposure to H(2)O(2). However, the 177/226-APE1 (repair deficient) did not show a protective effect. This phenomenon was further confirmed by the use of methoxyamine (MX), which blocks the repair activity of APE1 that results in enhanced cell killing and apoptosis in differentiated SH-SY5Y cells and in neuronal cultures after oxidative DNA damaging treatments. Blocking APE1 redox function by a small molecule inhibitor, BQP did not decrease viability of SH-SY5Y cells or neuronal cultures following oxidative DNA damaging treatments. Our results demonstrate that the DNA repair function of APE1 contributes to the survival of nondividing post-mitotic cells following oxidative DNA damage.
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Affiliation(s)
- Yanlin Jiang
- Department of Pediatrics (Section of Hematology/Oncology), Herman B Wells Center for Pediatric Research, United States
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18
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Geremia NM, Pettersson LME, Hasmatali JC, Hryciw T, Danielsen N, Schreyer DJ, Verge VMK. Endogenous BDNF regulates induction of intrinsic neuronal growth programs in injured sensory neurons. Exp Neurol 2009; 223:128-42. [PMID: 19646438 DOI: 10.1016/j.expneurol.2009.07.022] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/11/2009] [Accepted: 07/15/2009] [Indexed: 12/21/2022]
Abstract
Identification of the molecule(s) that globally induce a robust regenerative state in sensory neurons following peripheral nerve injury remains elusive. A potential candidate is brain-derived neurotrophic factor (BDNF), the sole neurotrophin upregulated in sensory neurons after peripheral nerve injury. Here we tested the hypothesis that BDNF plays a critical role in the regenerative response of mature rat sensory neurons following peripheral nerve lesion. Neutralization of endogenous BDNF was performed by infusing BDNF antibodies intrathecally via a mini-osmotic pump for 3 days at the level of the fifth lumbar dorsal root ganglion, immediately following unilateral spinal nerve injury. This resulted in decreased expression of the injury/regeneration-associated genes growth-associated protein-43 and Talpha1 tubulin in the injured sensory neurons as compared to injury plus control IgG infused or injury alone animals. Similar results were observed following inhibition of BDNF expression by intrathecal delivery of small interfering RNAs (siRNA) targeting BDNF starting 3 days prior to injury. The reduced injury/regeneration-associated gene expression correlated with a significantly reduced intrinsic capacity of these neurons to extend neurites when assayed in vitro. In contrast, delayed infusion of BDNF antibody for 3 days beginning 1 week post-lesion had no discernible influence on the elevated expression of these regeneration-associated markers. These results support an important role for endogenous BDNF in induction of the cell body response in injured sensory neurons and their intrinsic ability to extend neurites, but BDNF does not appear to be necessary for maintaining the response once it is induced.
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Affiliation(s)
- Nicole M Geremia
- Department of Anatomy and Cell Biology, Cameco MS Neuroscience Research Center University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E5
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19
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Clayton DF, George JM, Mello CV, Siepka SM. Conservation and expression of IQ-domain-containing calpacitin gene products (neuromodulin/GAP-43, neurogranin/RC3) in the adult and developing oscine song control system. Dev Neurobiol 2009; 69:124-40. [PMID: 19023859 DOI: 10.1002/dneu.20686] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Songbirds are appreciated for the insights they provide into regulated neural plasticity. Here, we describe the comparative analysis and brain expression of two gene sequences encoding probable regulators of synaptic plasticity in songbirds: neuromodulin (GAP-43) and neurogranin (RC3). Both are members of the calpacitin family and share a distinctive conserved core domain that mediates interactions between calcium, calmodulin, and protein kinase C signaling pathways. Comparative sequence analysis is consistent with known phylogenetic relationships, with songbirds most closely related to chicken and progressively more distant from mammals and fish. The C-terminus of neurogranin is different in birds and mammals, and antibodies to the protein reveal high expression in adult zebra finches in cerebellar Purkinje cells, which has not been observed in other species. RNAs for both proteins are generally abundant in the telencephalon yet markedly reduced in certain nuclei of the song control system in adult canaries and zebra finches: neuromodulin RNA is very low in RA and HVC (relative to the surrounding pallial areas), whereas neurogranin RNA is conspicuously low in Area X (relative to surrounding striatum). In both cases, this selective downregulation develops in the zebra finch during the juvenile song learning period, 25-45 days after hatching. These results suggest molecular parallels to the robust stability of the adult avian song control circuit.
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Affiliation(s)
- David F Clayton
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Illinois 61801, USA.
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20
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Zelano J, Plantman S, Hailer NP, Cullheim S. Altered expression of nectin-like adhesion molecules in the peripheral nerve after sciatic nerve transection. Neurosci Lett 2008; 449:28-33. [PMID: 18977278 DOI: 10.1016/j.neulet.2008.10.061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 09/29/2008] [Accepted: 10/14/2008] [Indexed: 12/30/2022]
Abstract
Following axotomy several processes involving cell-cell interaction occur, such as loss of synapses, axon guidance, and remyelination. Two recently discovered families of cell-cell adhesion molecules, nectins and nectin-like molecules (necls) are involved in such processes in vitro and during development, but their roles in nerve injury have been largely unknown until recently. We have previously shown that axotomized motoneurons increase their expression of nectin-1 and nectin-3 and maintain a high expression of necl-1. We here investigate the expression of potential binding partners for motoneuron nectins and necls in the injured peripheral nerve. In situ hybridization (ISH) revealed a decreased signal for necl-1 mRNA in the injured nerve, whereas no signal for necl-2 was detected before or after injury. The signals for necl-4 and necl-5 mRNA both increased in the injured nerve and necl immunoreactivity displayed a close relation to axon and Schwann cell markers. Finally, signal for mRNA encoding necl-5 increased in axotomized spinal motoneurons. We conclude that peripheral axotomy results in altered expression of several necls in motoneurons and Schwann cells, suggesting involvement of the molecules in regeneration.
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Affiliation(s)
- Johan Zelano
- Department of Neuroscience, Retzius väg 8, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
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21
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Tsai MC, Shen LF, Kuo HS, Cheng H, Chak KF. Involvement of acidic fibroblast growth factor in spinal cord injury repair processes revealed by a proteomics approach. Mol Cell Proteomics 2008; 7:1668-87. [PMID: 18482974 PMCID: PMC2556019 DOI: 10.1074/mcp.m800076-mcp200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 05/14/2008] [Indexed: 12/30/2022] Open
Abstract
Acidic fibroblast growth factor (aFGF; also known as FGF-1) is a potent neurotrophic factor that affects neuronal survival in the injured spinal cord. However, the pathological changes that occur with spinal cord injury (SCI) and the attribution to aFGF of a neuroprotective effect during SCI are still elusive. In this study, we demonstrated that rat SCI, when treated with aFGF, showed significant functional recovery as indicated by the Basso, Beattie, and Bresnahan locomotor rating scale and the combined behavior score (p < 0.01-0.001). Furthermore proteomics and bioinformatics approaches were adapted to investigate changes in the global protein profile of the damaged spinal cord tissue when experimental rats were treated either with or without aFGF at 24 h after injury. We found that 51 protein spots, resolvable by two-dimensional PAGE, had significant differential expression. Using hierarchical clustering analysis, these proteins were categorized into five major expression patterns. Noticeably proteins involved in the process of secondary injury, such as astrocyte activation (glial fibrillary acidic protein), inflammation (S100B), and scar formation (keratan sulfate proteoglycan lumican), which lead to the blocking of injured spinal cord regeneration, were down-regulated in the contusive spinal cord after treatment with aFGF. We propose that aFGF might initiate a series of biological processes to prevent or attenuate secondary injury and that this, in turn, leads to an improvement in functional recovery. Moreover the quantitative expression level of these proteins was verified by quantitative real time PCR. Furthermore we identified various potential neuroprotective protein factors that are induced by aFGF and may be involved in the spinal cord repair processes of SCI rats. Thus, our results could have a remarkable impact on clinical developments in the area of spinal cord injury therapy.
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Affiliation(s)
- Ming-Chu Tsai
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University, Taipei 11221, Taiwan
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22
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Watabe K, Ida H, Uehara K, Oyanagi K, Sakamoto T, Tanaka J, Garver WS, Miyawaki S, Ohno K, Eto Y. Establishment and characterization of immortalized Schwann cells from murine model of Niemann-Pick disease type C (spm/spm). J Peripher Nerv Syst 2008. [DOI: 10.1111/j.1529-8027.2001.01012.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Mantuano E, Mukandala G, Li X, Campana WM, Gonias SL. Molecular dissection of the human alpha2-macroglobulin subunit reveals domains with antagonistic activities in cell signaling. J Biol Chem 2008; 283:19904-11. [PMID: 18499670 DOI: 10.1074/jbc.m801762200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
alpha(2)-Macroglobulin (alpha(2)M) is a plasma protease inhibitor, which reversibly binds growth factors and, in its activated form, binds to low density lipoprotein receptor-related protein (LRP-1), an endocytic receptor with cell signaling activity. Because distinct domains in alpha(2)M are responsible for its various functions, we hypothesized that the overall effects of alpha(2)M on cell physiology reflect the integrated activities of multiple domains, some of which may be antagonistic. To test this hypothesis, we expressed the growth factor carrier site and the LRP-1 recognition domain (RBD) as separate GST fusion proteins (FP3 and FP6, respectively). FP6 rapidly and robustly activated Akt and ERK/MAP kinase in Schwann cells and PC12 cells. This response was blocked by LRP-1 gene silencing or by co-incubation with the LRP-1 antagonist, receptor-associated protein. The activity of FP6 also was blocked by mutating Lys(1370) and Lys(1374), which precludes LRP-1 binding. FP3 blocked activation of Akt and ERK/MAP kinase in response to nerve growth factor-beta (NGF-beta) but not FP6. In PC12 cells, FP6 promoted neurite outgrowth and expression of growth-associated protein-43, whereas FP3 antagonized the same responses when NGF-beta was added. The ability of FP6 to trigger LRP-1-dependent cell signaling in PC12 cells was reproduced by the 18-kDa RBD, isolated from plasma-purified alpha(2)M by proteolysis and chromatography. We propose that the effects of intact alpha(2)M on cell physiology reflect the degree of penetration of activities associated with different domains, such as FP3 and FP6, which may be regulated asynchronously by conformational change and by other regulatory proteins in the cellular microenvironment.
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Affiliation(s)
- Elisabetta Mantuano
- Department of Pathology and Anesthesiology, University of California San Diego, La Jolla, CA 92093, USA
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24
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McCluskey SU, Marotte LR, Ashwell KWS. Development of the vestibular apparatus and central vestibular connections in a wallaby (Macropus eugenii). BRAIN, BEHAVIOR AND EVOLUTION 2008; 71:271-86. [PMID: 18431054 DOI: 10.1159/000127047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Accepted: 02/08/2008] [Indexed: 11/19/2022]
Abstract
We have studied the early development of the vestibular apparatus and its central connections in the tammar wallaby (Macropus eugenii) in order to determine whether the vestibular system anatomy is sufficiently mature at birth to assist in climbing to the pouch. Structural development was studied with the aid of hematoxylin and eosin stained sections and immunoreactivity for GAP-43, whereas the development of vestibular system connections was examined by carbocyanine dye tracing. At the time of birth, the otocyst has distinct utricle, saccule and semicircular canals with immature sensory regions receiving innervation by GAP-43 immunoreactive fibers. Vestibular nerve fibers can be traced into the brainstem to the developing vestibular nuclei, which are not yet cytoarchitectonically distinct. The vestibular nuclei do not contribute direct projections to the lower cervical spinal cord at birth; most bulbospinal projections in the newborn appear to be derived bilaterally from the gigantocellular, lateral paragigantocellular reticular and ventral medullary nuclei. A substantial bilateral projection to the vestibular ganglion and apparatus from the region of the gigantocellular and lateral paragigantocellular nuclei was seen at birth, but not in subsequent ages. This is similar to a projection seen in newborn Ameridelphians. By postnatal day (P) 5, the vestibular apparatus had extensive projections to all vestibular nuclei and neurons projecting in the lateral vestibulospinal tract could be identified in the lateral vestibular nucleus. Cytoarchitectonic differentiation of the vestibular nuclei proceeded over the next 3 to 4 weeks with the emergence of discrete parvicellular and magnocellular components of the medial vestibular nucleus by P19. GAP-43 immunoreactivity stayed high in the lateral vestibulospinal tract for several months after birth, suggesting that the development of this tract followed a prolonged timecourse. Our findings indicate that central and peripheral connections of the vestibular ganglion are present at birth, but that there is no direct projection from the vestibular nuclei to the cervical spinal cord until P5. Nevertheless, the possibility remains that an indirect projection between the vestibular nuclei and the medial reticular formation is present at birth and mediates control of the climb.
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Affiliation(s)
- S U McCluskey
- Department of Anatomy, School of Medical Sciences, The University of NSW, Sydney, N.S.W., Australia
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25
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Ashwell KWS, Marotte LR, Cheng G. Development of the olfactory system in a wallaby (Macropus eugenii). BRAIN, BEHAVIOR AND EVOLUTION 2008; 71:216-30. [PMID: 18322362 DOI: 10.1159/000119711] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 11/20/2007] [Indexed: 11/19/2022]
Abstract
We used carbocyanine dye tracing techniques in conjunction with hematoxylin and eosin staining, immunohistochemistry for GAP-43, and tritiated thymidine autoradiography to examine the development of the olfactory pathways in early pouch young tammar wallabies (Macropus eugenii). The overarching aim was to test the hypothesis that the olfactory system of newborn tammars is sufficiently mature at birth to contribute to the guidance of the pouch young to the nipple. Although GAP-43 immunoreactive fibers emerge from the olfactory epithelium and enter the olfactory bulb at birth, all other components of the olfactory pathway in newborn tammars are very immature at birth, postnatal day (P0). In particular, maturation of the vomeronasal organ and its projections to the accessory olfactory bulb appears to be delayed until P5 and the olfactory bulb is poorly differentiated until P12, with glomerular formation delayed until P25. The lateral olfactory tract is also very immature at birth with pioneer axons having penetrated only the most rostral portion of the piriform lobe. Interestingly, there were some early (P0) projections from the olfactory epithelium to the medial septal region and lamina terminalis (by the terminal nerve) and to olfactory tubercle and basal forebrain. The former of these is presumably serving the transfer of LHRH(+) neurons to the forebrain, as seen in eutherians, but neither of these very early pathways is sufficiently robust or connected to the more caudal neuraxis to play a role in nipple finding. Tritiated thymidine autoradiography confirmed that most piriform cortex pyramidal neurons are generated in the first week of life and are unlikely to be able to contribute to circuitry guiding the climb to the pouch. Our findings lead us to reject the hypothesis that olfactory projections contribute to guidance of the newborn tammar to the pouch and nipple. It appears far more likely that the trigeminal pathways play a significant role in this behavior because the central projections of the trigeminal nerve are more mature at birth in this marsupial.
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Affiliation(s)
- K W S Ashwell
- Department of Anatomy, School of Medical Sciences, The University of NSW, Sydney, NSW, Australia.
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Zelano J, Wallquist W, Hailer NP, Cullheim S. Down-regulation of mRNAs for synaptic adhesion molecules neuroligin-2 and -3 and synCAM1 in spinal motoneurons after axotomy. J Comp Neurol 2007; 503:308-18. [PMID: 17492651 DOI: 10.1002/cne.21382] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
After peripheral axotomy, synapses are eliminated from the somata of spinal motoneurons. Recent evidence indicates that synaptic adhesion molecules play a role in maintenance of synaptic contacts, but so far such molecules have not been investigated in the context of synapse elimination after injury. In vitro, the neuroligins (NLGs) and SynCAM1 drive formation of synapses, and RNAi of NLGs results in decreased synaptic input, indicating an important role for these molecules in synaptic biology. To address potential involvement of NLGs and SynCAMs in postinjury synapse elimination, we investigated the mRNA expression of NLG1, -2, and -3; SynCAM1 and -3; and PSD-95--an intracellular NLG-binding scaffolding protein--in rat spinal motoneurons in control animals and after sciatic nerve transection (SNT). mRNA signals for NLG2, NLG3, SynCAM1, and SynCAM3, but not NLG1, were seen in uninjured motoneurons. Immunoreactivity for SynCAM was seen in close relation to synaptophysin immunoreactivity on the surface of motoneurons and in close relation to neurofilament immunoreactivity in the sciatic nerve. After axotomy, the signals for NLG2, NLG3, and SynCAM1 mRNAs decreased, whereas the signal for NLG1 mRNA remained undetectable and that for SynCAM3 remained at control levels. The signal for PSD-95 mRNA decreased gradually and reached approximately 50% of control values 2 weeks after axotomy. Thus the retrograde response to axotomy of spinal motoneurons involves a rapid down-regulation of NLG2, NLG3, and SynCAM1 mRNAs and a gradual decrease in PSD-95 mRNA. This indicates that down-regulation of synaptic adhesion molecules plays a role in postinjury synapse elimination.
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Affiliation(s)
- Johan Zelano
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
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27
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Geremia NM, Gordon T, Brushart TM, Al-Majed AA, Verge VMK. Electrical stimulation promotes sensory neuron regeneration and growth-associated gene expression. Exp Neurol 2007; 205:347-59. [PMID: 17428474 DOI: 10.1016/j.expneurol.2007.01.040] [Citation(s) in RCA: 293] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 01/16/2007] [Accepted: 01/19/2007] [Indexed: 12/29/2022]
Abstract
Brief electrical stimulation enhances the regenerative ability of axotomized motor [Nix, W.A., Hopf, H.C., 1983. Electrical stimulation of regenerating nerve and its effect on motor recovery. Brain Res. 272, 21-25; Al-Majed, A.A., Neumann, C.M., Brushart, T.M., Gordon, T., 2000. Brief electrical stimulation promotes the speed and accuracy of motor axonal regeneration. J. Neurosci. 20, 2602-2608] and sensory [Brushart, T.M., Jari, R., Verge, V., Rohde, C., Gordon, T., 2005. Electrical stimulation restores the specificity of sensory axon regeneration. Exp. Neurol. 194, 221-229] neurons. Here we examined the parameter of duration of stimulation on regenerative capacity, including the intrinsic growth programs, of sensory neurons. The effect of 20 Hz continuous electrical stimulation on the number of DRG sensory neurons that regenerate their axons was evaluated following transection and surgical repair of the femoral nerve trunk. Stimulation was applied proximal to the repair site for 1 h, 3 h, 1 day, 7 days or 14 days at the time of nerve repair. Following a 21-day regeneration period, DRG neurons that regenerated axons into the muscle and cutaneous sensory nerve branches were retrogradely identified. Stimulation of 1 h led to a significant increase in DRG neurons regenerating into cutaneous and muscle branches when compared to 0 h (sham) stimulation or longer periods of stimulation. Stimulation for 1 h also significantly increased the numbers of neurons that regenerated axons beyond the repair site 4 days after lesion and was correlated with a significant increase in expression of growth-associated protein 43 (GAP-43) mRNA in the regenerating neurons at 2 days post-repair. An additional indicator of heightened plasticity following 1 h stimulation was elevated expression of brain-derived neurotrophic factor (BDNF). The effect of brief stimulation on enhancing sensory and motoneuron regeneration holds promise for inducing improved peripheral nerve repair in the clinical setting.
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Affiliation(s)
- Nicole M Geremia
- Department of Anatomy and Cell Biology, Cameco MS/Neuroscience Research Center University of Saskatchewan, Saskatoon City Hospital, Saskatchewan, Canada
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28
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Martinez JL, Thompson KJ, Sikorski AM. Gene expression in learning and memory. Neurobiol Learn Mem 2007. [DOI: 10.1016/b978-012372540-0/50005-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Cheng G, Zhu H, Zhou X, Qu J, Ashwell KWS, Paxinos G. Development of the human nucleus of the solitary tract: a cyto- and chemoarchitectural study. Auton Neurosci 2006; 128:76-95. [PMID: 16720106 DOI: 10.1016/j.autneu.2006.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Revised: 01/25/2006] [Accepted: 04/07/2006] [Indexed: 10/24/2022]
Abstract
The present study investigated the prenatal development of the cyto- and chemoarchitecture of the human nucleus of the solitary tract from 9 to 35 weeks, by using Nissl staining and immunoreactivity to calbindin, calretinin, tyrosine hydroxylase and GAP-43. The nucleus began to gain heterogeneity and show different subnuclei as early as 13 weeks, and approached cytoarchitectural maturation from 21 to 25 weeks. The subnuclear division pattern observed in the fetal nucleus of the solitary tract at 25 weeks was very similar to that of the adult. Neurons immunoreactive to calbindin first appeared in the medial gastrointestinal area of the nucleus at 13 weeks, particularly within a putative gelatinosus subnucleus, while calretinin immunoreactivity during fetal life suggested the possible presence of a central subnucleus. Tyrosine hydroxylase immunoreactive neurons were seen in the medial subdivisions of the nucleus of the solitary tract as early as 13 weeks, but the population continued to increase until 25 weeks. Strong GAP-43 immunoreactivity was also present in the nucleus of the solitary tract at 13 weeks, especially in the dorsolateral and commissural subnuclei, while at 21 weeks there was a significant decline of GAP-43 expression. Results from the chemoarchitectural study showed that the human nucleus of the solitary tract expressed various neurochemical substances at an early developmental age (13 weeks), even before cellular and neuropil maturation was fully attained. Expression of these factors may play an important role in establishment and integration of viscerosensory function in the nucleus.
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Affiliation(s)
- Gang Cheng
- Prince of Wales Medical Research Institute, Barker St. Randwick 2031 NSW, Australia.
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30
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Murata R, Ohtori S, Ochiai N, Takahashi N, Saisu T, Moriya H, Takahashi K, Wada Y. Extracorporeal shockwaves induce the expression of ATF3 and GAP-43 in rat dorsal root ganglion neurons. Auton Neurosci 2006; 128:96-100. [PMID: 16716760 DOI: 10.1016/j.autneu.2006.04.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2005] [Revised: 04/11/2006] [Accepted: 04/13/2006] [Indexed: 11/25/2022]
Abstract
Although extracorporeal shockwave has been applied in the treatment of various diseases, the biological basis for its analgesic effect remains unclear. Therefore, we investigated the dorsal root ganglion neurons of rats following shockwave exposure to the footpad to elucidate its effect on the peripheral nervous system. We used activating transcription factor 3 (ATF3) and growth-associated phosphoprotein (GAP-43) as markers for nerve injury and axonal regeneration, respectively. The average number of neurons immunoreactive for ATF3 increased significantly in the treated rats at all experimental time points, with 78.3% of those neurons also exhibiting immunoreactivity for GAP-43. Shockwave exposure induced injury of the sensory nerve fibers within the exposed area. This phenomenon may be linked to the desensitization of the exposure area, not the cause of pain, considering clinical research with a particular absence of painful adverse effect. Subsequent active axonal regeneration may account for the reinnervation of exposed area and the amelioration of the desensitization.
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Affiliation(s)
- Ryo Murata
- Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, and Division of Orthopaedic Surgery, Chiba Children's Hospital, Japan.
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31
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Imamura K, Morii H, Nakadate K, Yamada T, Mataga N, Watanabe Y, Mori N. Brain-derived neurotrophic factor enhances expression of superior cervical ganglia clone 10 in lateral geniculate nucleus and visual cortex of developing kittens. Eur J Neurosci 2006; 23:637-48. [PMID: 16487145 DOI: 10.1111/j.1460-9568.2006.04592.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Neuronal growth-associated proteins, including superior cervical ganglia clone 10 (SCG10) family molecules, play roles in neurite outgrowth and network formation as well as structural and functional plasticity. The present ontogenetic study revealed that the expression of neuronal growth-associated proteins in the visual cortex (VC) exhibited a sharp peak in the early postnatal period when growing lateral geniculate nucleus (LGN) axon terminals segregate into the ocular dominance columns depending on retinal activity. We then hypothesized that SCG10 family molecules, known for catastrophic factors of microtubules, play important roles in the formation of ocular dominance columns. To test this hypothesis, we studied whether: (i) monocular blockade of retinal activity changed the SCG10 expression in LGN and VC and (ii) brain-derived neurotrophic factor (BDNF) cortical infusion modified the expression of SCG10 family molecules and the number of excitatory/inhibitory cortical synapses. Using northern blot and in situ hybridization, we revealed that: (i) silencing retinal activity with tetrodotoxin eye injections dynamically reduced the expression of SCG10 mRNA and (ii) it was enhanced by BDNF in VC and LGN of kittens but not adult cats. These findings suggest that cortical infusion of BDNF and retinal activity up-regulate the expression of SCG10 in the LGN and VC and that up-regulated SCG10 in turn initiates marked reorganization of the microtuble network, eventually resulting in increase in synapse formation in the VC.
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Affiliation(s)
- Kazuyuki Imamura
- Department of Neuroscience, Osaka Bioscience Institute, Suita-shi, Osaka, Japan.
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32
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Qu J, Zhou X, Zhu H, Cheng G, Ashwell KWS, Lu F. Development of the human superior colliculus and the retinocollicular projection. Exp Eye Res 2006; 82:300-10. [PMID: 16125175 DOI: 10.1016/j.exer.2005.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 06/29/2005] [Accepted: 07/04/2005] [Indexed: 11/15/2022]
Abstract
We have used carbocyanine dye tracing from the brachium of the superior colliculus in conjunction with Nissl staining and immunohistochemistry to GAP-43 and calretinin to study the development of retinal projections to the superior colliculus in 17 human embryos and fetuses aged from 8 to 28 weeks. Lamination of the superior colliculus begins to emerge by 11 weeks, and by 16 weeks all seven layers of the mature superior colliculus are visible. Fibres immunoreactive to GAP-43 were seen at 13 weeks in the most superficial layers. By 19 weeks, GAP-43 immunoreactivity was present in the stratum opticum as well as the deeper fibres layers, indicating the development of fibre pathways following those laminae. Carbocyanine dye tracing of retinocollicular projections showed extensive rostrocaudally running unbranched fibres in the superficial superior colliculus at 12 weeks. Shortly after this (13 weeks), retinocollicular fibres penetrate the deeper collicular layers and branching becomes apparent. We also saw occasional retrogradely labelled somata following DiI insertion into the superior brachium. Our findings indicate that development of the human superior colliculus and its connections is largely complete by 20 weeks. This would suggest that functional capacity of the human superior colliculus should also be mature by the middle of gestation.
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Affiliation(s)
- Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325003, China
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33
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Schofield EC, Clausen JA, Burcher E, Moore KH. GAP-43 immunoreactivity of subepithelial and detrusor muscle nerve fibres in patients with refractory idiopathic detrusor overactivity. Neurourol Urodyn 2005; 24:325-33. [PMID: 15924356 DOI: 10.1002/nau.20140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
AIMS To determine the relative density of nerve fibres immunoreactive to growth associated protein-43 (GAP-43, an indicator of neuronal sprouting) in the subepithelium and detrusor of patients with idiopathic detrusor overactivity (IDO). To investigate the effect, if any, of age and previous recurrent bacterial cystitis on neuronal sprouting in such patients. MATERIALS AND METHODS A series of 18 women with urodynamically proven IDO (median age 62 years, range 39-85), who were refractory to treatment, underwent cystoscopy and cold cup biopsy. Controls (n=26, median age 65, range 32-79) were females without urgency/urge incontinence, undergoing cystoscopy for other indications. Recurrent proven bacterial cystitis (rUTI) was documented. Frozen sections were stained with specific antibodies to GAP-43 and protein gene product 9.5 (PGP, a general neuronal marker). The area represented by immunoreactive (ir) subepithelial or muscle nerve fibres was measured. RESULTS The density of GAP-43ir and PGPir nerves did not differ significantly between IDO patients and controls, in either subepithelium or detrusor. The GAP-43ir nerve density (as percent of PGPir) increased significantly with advancing age amongst patients with IDO in the detrusor muscle but not in the subepithelium; density in controls was unaltered. In IDO patients with rUTI, a significant increase in GAP-43 (as percent of PGPir) was observed in the subepithelium. CONCLUSIONS Although we found no evidence of increased neuronal proliferation in patients with IDO generally, the increase in GAP-43 with age and with previous cystitis history suggests that neuronal sprouting is important in some subsets of patients with IDO.
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Affiliation(s)
- E C Schofield
- The Detrusor Muscle Laboratory, Department of Urogynaecology, St. George Hospital, University of New South Wales, Sydney, Australia
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34
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Grundt K, Haga IV, Aleporou-Marinou V, Drosos Y, Wanvik B, Østvold AC. Characterisation of the NUCKS gene on human chromosome 1q32.1 and the presence of a homologous gene in different species. Biochem Biophys Res Commun 2004; 323:796-801. [PMID: 15381070 DOI: 10.1016/j.bbrc.2004.08.153] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Indexed: 10/26/2022]
Abstract
The NUCKS gene is located on human chromosome 1q32.1 and consists of seven exons and six introns. The gene lacks a TATA box but contains two Inr elements, two GC boxes, and one consensus-binding site for E2F-1. NUCKS is expressed in all human adult and foetal tissues investigated, and has all the features of being a housekeeping gene. Both data searches and Western immunoblotting experiments show that a homologous protein is present in fish, amphibians, and birds but not in insects and yeast, suggesting that NUCKS is a vertebrate specific gene. In all the species investigated, the protein contains several consensus phosphorylation sites for cyclin-dependent kinases and CK-2, and we have shown that the fish protein (like mammalian NUCKS) indeed is a substrate for CDK1 and CK-2 in vitro. The NUCKS protein is also conserved with respect to a DNA-binding domain previously characterised in mammals, and two putative bipartite nuclear localisation signals.
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Affiliation(s)
- Kirsten Grundt
- Department of Medical Biochemistry, Institute Group of Basic Medical Sciences, University of Oslo, Norway.
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35
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Wallquist W, Zelano J, Plantman S, Kaufman SJ, Cullheim S, Hammarberg H. Dorsal root ganglion neurons up-regulate the expression of laminin-associated integrins after peripheral but not central axotomy. J Comp Neurol 2004; 480:162-9. [PMID: 15514929 DOI: 10.1002/cne.20345] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The favorable prognosis of regeneration in the peripheral nervous system after axonal lesions is generally regarded as dependent on the Schwann cell basal lamina. Laminins, a heterotrimeric group of basal lamina molecules, have been suggested to be among the factors playing this supportive role. For neurons to utilize laminin as a substrate for growth, an expression of laminin binding receptors, integrins, is necessary. In this study, we have examined the expression of laminin binding integrin subunits in dorsal root ganglion (DRG) neurons after transection to either their peripherally projecting axons, as in the sciatic nerve, followed by regeneration, or the centrally projecting axons in dorsal roots, followed by no or weak regenerative activity. In uninjured DRG, immunohistochemical staining revealed a few neurons expressing integrin subunit alpha6, whereas integrin subunits alpha7 and foremost beta1 were expressed in a majority of neurons. After an injury to the sciatic nerve, mRNAs encoding all three integrins were up-regulated in DRG neurons. By anterograde tracing, immunoreactivity for all studied integrins was also found in association with growing axons after a sciatic nerve crush lesion in vivo. In contrast, mRNA levels remained constant in DRG neurons after a dorsal root injury. Together with previous findings, this suggests that integrin subunits alpha6, alpha7, and beta1 have an important role in the regenerative response following nerve injury and that the lack of regenerative capacity following dorsal root injury could in part be explained by the absence of response in integrin regulation.
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Affiliation(s)
- Wilhelm Wallquist
- Department of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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36
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Gauthier-Campbell C, Bredt DS, Murphy TH, El-Husseini AED. Regulation of dendritic branching and filopodia formation in hippocampal neurons by specific acylated protein motifs. Mol Biol Cell 2004; 15:2205-17. [PMID: 14978216 PMCID: PMC404016 DOI: 10.1091/mbc.e03-07-0493] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Revised: 02/01/2004] [Accepted: 02/02/2004] [Indexed: 11/11/2022] Open
Abstract
Although neuronal axons and dendrites with their associated filopodia and spines exhibit a profound cell polarity, the mechanism by which they develop is largely unknown. Here, we demonstrate that specific palmitoylated protein motifs, characterized by two adjacent cysteines and nearby basic residues, are sufficient to induce filopodial extensions in heterologous cells and to increase the number of filopodia and the branching of dendrites and axons in neurons. Such motifs are present at the N-terminus of GAP-43 and the C-terminus of paralemmin, two neuronal proteins implicated in cytoskeletal organization and filopodial outgrowth. Filopodia induction is blocked by mutations of the palmitoylated sites or by treatment with 2-bromopalmitate, an agent that inhibits protein palmitoylation. Moreover, overexpression of a constitutively active form of ARF6, a GTPase that regulates membrane cycling and dendritic branching reversed the effects of the acylated protein motifs. Filopodia induction by the specific palmitoylated motifs was also reduced upon overexpression of a dominant negative form of the GTPase cdc42. These results demonstrate that select dually lipidated protein motifs trigger changes in the development and growth of neuronal processes.
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Affiliation(s)
- Catherine Gauthier-Campbell
- Department of Psychiatry and the Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
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37
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Pettersson LME, Heine T, Verge VMK, Sundler F, Danielsen N. PACAP mRNA is expressed in rat spinal cord neurons. J Comp Neurol 2004; 471:85-96. [PMID: 14983478 DOI: 10.1002/cne.20015] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This study examines the expression of pituitary adenylate cyclase activating polypeptide (PACAP) mRNA in the rat spinal cord during normal conditions and in response to sciatic nerve transection. Previously, PACAP immunoreactivity has been found in fibers in the spinal cord dorsal horn and around the central canal and in neurons in the intermediolateral column (IML). Furthermore, in the dorsal root ganglia, PACAP immunoreactivity and PACAP mRNA expression have been observed preferentially in nerve cell bodies of smaller diameter terminating in the superficial laminae of the dorsal horn. However, neuronal expression of PACAP mRNA in adult rat spinal cord appeared limited to neurons of the IML. By using a refined in situ hybridization protocol, we now detect PACAP mRNA expression in neurons primarily in laminae I and II, but also in deeper laminae of the spinal cord dorsal horn and around the central canal. In addition, PACAP mRNA expression is observed in a few neurons in the ventral horn. PACAP expression in the ventral horn is increased in a population of large neurons, most likely motor neurons, both after distal and proximal sciatic nerve transection. The proposed role of PACAP in nociception is strengthened by our findings of PACAP mRNA-expressing neurons in the superficial laminae of the dorsal horn. Furthermore, increased expression of PACAP in ventral horn neurons, in response to nerve transection, suggests a role for PACAP in repair/regeneration of motor neurons.
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Affiliation(s)
- Lina M E Pettersson
- Department of Physiological Sciences, Section for Neuroendocrine Cell Biology, Lund University, SE-221 84 Lund, Sweden.
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38
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Lipson AC, Widenfalk J, Lindqvist E, Ebendal T, Olson L. Neurotrophic properties of olfactory ensheathing glia. Exp Neurol 2003; 180:167-71. [PMID: 12684030 DOI: 10.1016/s0014-4886(02)00058-4] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Olfactory ensheathing cells (OEC) constitute a specialized population of glia that accompany primary olfactory axons and have been reported to facilitate axonal regeneration after spinal cord injury in vivo. In the present report we describe OEC neurotrophic factor expression and neurotrophic properties of OECs in vitro. Investigation of the rat olfactory system during development and adulthood by radioactive in situ hybridization revealed positive labeling in the olfactory nerve layer for the neurotrophic molecules S-100beta, CNTF, BMP-7/OP-1, and artemin, as well as for the neurotrophic factor receptors RET and TrkC. Ribonuclease protection assay of cultured OEC revealed expression of NGF, BDNF, GDNF, and CNTF mRNA, while NT3 and NT4 mRNA were not detectable. In vitro bioassays of neurotrophic activity involved coculturing of adult OEC with embryonic chick ganglia and demonstrated increased neurite outgrowth from sympathetic, ciliary, and Remak's ganglia. However, when culturing the ganglia with OEC-conditioned medium, neurite outgrowth was not stimulated to any detectable extent. Our results suggest that the neurotrophic properties of OEC may involve secretion of neurotrophic molecules but that cellular interactions are crucial.
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Affiliation(s)
- Adam C Lipson
- Department of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden
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39
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Grundt K, Skjeldal L, Anthonsen HW, Skauge T, Huitfeldt HS, Østvold AC. A putative DNA-binding domain in the NUCKS protein. Arch Biochem Biophys 2002; 407:168-75. [PMID: 12413487 DOI: 10.1016/s0003-9861(02)00513-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have studied the DNA-binding properties of a NUCKS-derived, synthetic peptide containing an extended GRP motif. This peptide binds to random-sequence DNA, but did not bind preferentially to poly(dA-dT). A synthetic peptide with the same amino acid composition but with a random sequence did not bind to DNA, suggesting that the structure of the DNA-binding domain plays a pivotal role in the interaction with DNA. NMR and graphic modeling were employed to investigate the structure of the synthetic peptide. It was shown that the DNA-binding peptide constituted an alpha helix in phosphate buffer at pH 5.5. Docking results indicated an almost perfect fit for this small, helical peptide into the major groove of DNA with the possibility of four basic residues interacting with the phosphate backbone of DNA. One consensus site for phosphorylation by Cdk1 is located in the N-terminal end of the DNA-binding peptide. Upon phosphorylation of this site, the binding to DNA was completely prohibited. Immunofluorescence experiments showed that NUCKS was located in the nuclei in proliferating cells in interphase of the cell cycle, but was distributed throughout the cytoplasm in mitotic cells.
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Affiliation(s)
- Kirsten Grundt
- Department of Medical Biochemistry, University of Oslo, Box 1115 Blindern, Oslo, Norway
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40
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Cheng G, Marotte LR, Mai JK, Ashwell KWS. Early development of the hypothalamus of a wallaby (Macropus eugenii). J Comp Neurol 2002; 453:199-215. [PMID: 12373784 DOI: 10.1002/cne.10395] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have studied the development of the hypothalamus of an Australian marsupial, the tammar wallaby (Macropus eugenii), to provide an initial anatomic framework for future research on the developing hypothalamus of diprotodontid metatheria. Cytoarchitectural (hematoxylin and eosin), immunohistochemical (CD 15 and growth associated protein, GAP-43), tritiated thymidine autoradiography, and carbocyanine dye tracing techniques were applied. Until 12 days after birth (P12), the developing hypothalamus consisted of mainly a ventricular germinal zone with a thin marginal layer, but by P25, most hypothalamic nuclei were well differentiated, indicating that the bulk of hypothalamic cytoarchitectural development occurs between P12 and P25. Strong CD 15 immunoreactivity was found in radial glial fibers in the rostral hypothalamus during early developmental ages, separating individual hypothalamic compartments. Immunoreactivity for GAP-43 was used to reveal developing fiber bundles. The medial forebrain bundle was apparent by P0, and the fornix appeared at P12. Tritiated thymidine autoradiography revealed lateral-to-medial and dorsal-to-ventral neurogenetic gradients similar to those seen in rodents. Dye tracing showed that projections to the posterior pituitary arose from the supraoptic nucleus at P5 and from the paraventricular nucleus at P10. Projections to the medulla were first found from the lateral hypothalamic area at P0 and paraventricular nucleus at P10. In conclusion, the pattern of development of the wallaby hypothalamus is broadly similar to that found in eutheria, with comparable neurogenetic compartments to those identified in rodents. Because most hypothalamic maturation takes place after birth, wallabies provide a useful model for experimentally manipulating the developing mammalian hypothalamus.
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Affiliation(s)
- Gang Cheng
- Department of Anatomy, School of Medical Sciences, The University of New South Wales, 2052 New South Wales, Australia.
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41
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Arvidsson U, Risling M, Cullheim S, Dagerlind A, Lindå H, Shupliakov O, Ulfhake B, Hökfelt T. On the Distribution of GAP-43 and its Relation to Serotonin in Adult Monkey and Cat Spinal Cord and Lower Brainstem. Eur J Neurosci 2002; 4:777-784. [PMID: 12106322 DOI: 10.1111/j.1460-9568.1992.tb00187.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
By use of a monoclonal antibody, the distribution of growth-associated protein (GAP)-43-like immunoreactivity (LI) has been studied in the spinal cord of adult grey monkeys (Macaca fascicularis) and adult cats by use of immunofluorescence and peroxidase - antiperoxidase techniques. The brainstem was also studied with in situ hybridization histochemistry. In both monkeys and cats, a dense innervation of GAP-43-immunoreactive (IR) fibres was seen in close apposition to large cell bodies and their processes in the motor nucleus of the ventral horn. Double-labelling experiments revealed a high degree of coexistence between GAP-43- and 5-hydroxytryptamine (5-HT, serotonin)-LI in the monkey motor nucleus, while in the cat no such colocalization could be verified. At the electron microscopic level, GAP-43 labelling was seen as a coating of vesicles and axolemma inside the terminals. In both monkey and cat, cell bodies expressing mRNA encoding GAP-43 were demonstrated in the medullary midline raphe nuclei. A similar location was also encountered for mRNA for aromatic l-amino acid decarboxylase, an enzyme found in both catecholamine- and serotonin-containing neurons. The present results suggest that GAP-43 is present in the 5-HT bulbospinal pathway of the monkey. In the cat, GAP-43 mRNA-expressing cell bodies were demonstrated in areas where descending 5-HT neurons are located, but no convincing colocalization of 5-HT- and GAP-43-LI was found at spinal cord levels, despite the existence of extensive fibre networks containing either of the two compounds. Possible explanations for this species discrepancy are discussed. The function of GAP-43 in nerve terminals impinging on the motoneurons is unknown. However, it may play a role in transmitter release and/or plasticity, since such roles have been proposed for this protein in other systems.
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42
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Biffo S, Verhaagen J, Schrama LH, Schotman P, Danho W, Margolis FL. B-50/GAP43 Expression Correlates with Process Outgrowth in the Embryonic Mouse Nervous System. Eur J Neurosci 2002; 2:487-499. [PMID: 12106019 DOI: 10.1111/j.1460-9568.1990.tb00440.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The hypothesis that B-50/GAP43, a membrane-associated phosphoprotein, is involved in process outgrowth has been tested by studying the developmental pattern of expression of B-50/GAP43 mRNA and protein during mouse neuroembryogenesis. B-50/GAP43 mRNA is first detectable at embryonic day 8.5 (E8.5) in the presumptive acoustico-facialis ganglion. Subsequently, both B-50/GAP43 mRNA and protein were co-expressed in a series of neural structures: in the ventral neural tube (from E9.5) and dorsal root ganglia (from E10.5), in the marginal layer of the neuroepithelium surrounding the brain vesicles and in the cranial ganglia (from E9.5), in the autonomic nervous system (from E10.5), in the olfactory neuroepithelium and in the mesenteric nervous system (from E11.5), in a continuum of brain regions (from E12.5) and in the retina (from E13.5). Immunoreactive fibers were always seen arising from these regions when they expressed B-50/GAP43 mRNA. The spatial and temporal pattern of B-50/GAP43 expression demonstrates that this protein is absent from neuroblasts and consistently appears in neurons committed to fiber outgrowth. The expression of the protein in immature neurons is independent of their embryological origin. Our detailed study of B-50/GAP43 expression during mouse neuroembryogenesis supports the view that this protein is involved in a process common to all neurons elaborating fibers.
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Affiliation(s)
- S. Biffo
- Department of Neurosciences, Roche Institute of Molecular Biology, Roche Research Center, Nutley, New Jersey 07110, USA
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43
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Wood SJ, Pritchard J, Sofroniew MV. Re-expression of Nerve Growth Factor Receptor after Axonal Injury Recapitulates a Developmental Event in Motor Neurons: Differential Regulation when Regeneration is Allowed or Prevented. Eur J Neurosci 2002; 2:650-7. [PMID: 12106299 DOI: 10.1111/j.1460-9568.1990.tb00454.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Motor neurons in the brainstem and spinal cord transiently express nerve growth factor receptors (NGFr) during development, but not in normal adult animals. In this study, NGFr was immunohistochemically identified in hypoglossal motor neurons after different types of peripheral axonal injury in adult rats. NGFr is re-expressed in motor neurons 7 days after a nerve crush injury, and has disappeared again by 28 days. These times correspond, respectively, to the active phase of regeneration, and a time by which regeneration has largely been completed, as determined by electrical activation of tongue muscle twitch. In contrast, 7 days after nerve transection and ligation of the proximal stump to prevent regeneration, there is no re-expression of NGFr, but 28 days after such treatment NGFr is present in a few neurons. By this time, neuroma formation has begun proximal to the end of the cut and ligated nerve. Together, these findings suggest that motor neurons transiently re-express NGFr during regeneration and not in response to axonal transection per se. The signal triggering re-expression thus seems more likely to be the introduction of a message from the site of injury, rather than the loss of a target-derived message. Although the function of NGFr in developing and regenerating motor neurons is not known, its expression appears to be associated with periods of axonal growth and maturation.
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Affiliation(s)
- S J Wood
- Department of Anatomy, Downing Street, University of Cambridge, Cambridge CB2 3DY, UK
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44
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Morton AJ, Buss TN. Accelerated Differentiation in Response to Retinoic Acid After Retrovirally Mediated Gene Transfer of GAP-43 into Mouse Neuroblastoma Cells. Eur J Neurosci 2002; 4:910-916. [PMID: 12106426 DOI: 10.1111/j.1460-9568.1992.tb00117.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although substantial evidence exists for the involvement of growth-associated protein-43 (GAP-43) in neuronal development and regeneration, the precise role of this protein in neurite outgrowth is currently debated. To investigate the role of GAP-43 in the initiation of neurite outgrowth, we transfected a full-length cDNA coding for GAP-43 into a mouse neuroblastoma cell line (Neuro-2a) which can be differentiated to a neuronal phenotype using retinoic acid (RA). We show that the consequent overexpression of GAP-43 results in a change in the basic morphology of these cells, but is not in itself sufficient to induce the extension of neurites. However, overexpression of GAP-43 results in a marked acceleration of neurite formation in response to RA. We propose that while GAP-43 does not trigger the initiation of neurite extension, its expression is rate-limiting for neurite outgrowth in response to differentiation agents such as RA.
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Affiliation(s)
- A. Jennifer Morton
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QJ, UK
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Grabczyk E, Zuber MX, Federoff HJ, Ng SC, Pack A, Fishman MC. Cloning and Characterization of the Rat Gene Encoding GAP-43. Eur J Neurosci 2002; 2:822-827. [PMID: 12106089 DOI: 10.1111/j.1460-9568.1990.tb00393.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
GAP-43 is a gene expressed only in the nervous system. The protein product is believed to be important to neuronal growth and plasticity. Most, and likely all, neurons express high levels of GAP-43 during periods of neurite elongation. To initiate studies of GAP-43 gene regulation we have cloned the rat gene encoding GAP-43. The GAP-43 gene includes three exons. The first exon encodes only the amino terminal 10 amino acids, which corresponds to the membrane targeting domain of GAP-43. The second exon encodes a putative calmodulin binding domain and a protein kinase C phosphorylation site. The 5'-flanking sequence is unusual in that it lacks CAAT or TATA elements, and directs RNA transcription initiation from several sites. Some of the transcription start sites are used to a different degree in the central and peripheral nervous systems.
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Affiliation(s)
- Ed Grabczyk
- Developmental Biology Laboratory, Massachusetts General Hospital, Department of Medicine, Harvard Medical School, and Howard Hughes Medical Institute, Boston, MA, USA
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Chong MS, Fitzgerald M, Winter J, Hu-Tsai M, Emson PC, Wiese U, Woolf CJ. GAP-43 mRNA in Rat Spinal Cord and Dorsal Root Ganglia Neurons: Developmental Changes and Re-expression Following Peripheral Nerve Injury. Eur J Neurosci 2002; 4:883-95. [PMID: 12106424 DOI: 10.1111/j.1460-9568.1992.tb00115.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The expression of growth-associated protein GAP-43 mRNA in spinal cord and dorsal root ganglion (DRG) neurons has been studied using an enzyme linked in situ hybridization technique in neonatal and adult rats. High levels of GAP-43 mRNA are present at birth in the majority of spinal cord neurons and in all dorsal root ganglion cells. This persists until postnatal day 7 and then declines progressively to near adult levels (with low levels of mRNA in spinal cord motor neurons and 2000 - 3000 DRG cells expressing high levels) at postnatal day 21. A re-expression of GAP-43 mRNA in adult rats is apparent, both in sciatic motor neurons and the majority of L4 and L5 dorsal root ganglion cells, 1 day after sciatic nerve section. High levels of the GAP-43 mRNA in the axotomized spinal motor neurons persist for at least 2 weeks but decline 5 weeks after sciatic nerve section, with the mRNA virtually undetectable after 10 weeks. The initial changes after sciatic nerve crush are similar, but by 5 weeks GAP-43 mRNA in the sciatic motor neurons has declined to control levels. In DRG cells, after both sciatic nerve section or crush, GAP-43 mRNA re-expression persists much longer than in motor neurons. There was no re-expression of GAP-43 mRNA in the dorsal horn of the spinal cord after peripheral nerve lesions. Our study demonstrates a similar developmental regulation in spinal cord and DRG neurons of GAP-43 mRNA. We show moreover that failure of re-innervation does not result in a maintenance of GAP-43 mRNA in axotomized motor neurons.
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Affiliation(s)
- M S Chong
- Department of Anatomy and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
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Tsuzuki K, Noguchi K, Mohri D, Yasuno H, Umemoto M, Shimobayashi C, Fukazawa K, Sakagami M. Expression of activating transcription factor 3 and growth-associated protein 43 in the rat geniculate ganglion neurons after chorda tympani injury. Acta Otolaryngol 2002; 122:161-7. [PMID: 11936907 DOI: 10.1080/00016480252814162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The purpose of this study was to evaluate the degree of damage in the geniculate ganglion and its target organ as a result of chorda tympani (CT) injury. We performed unilateral transection of the rat CT and examined expression of the activating transcription factor 3 (ATF3), a neuronal injury marker, and the growth-associated protein 43 (GAP-43), a regeneration-associated molecule. The mean proportion of ATF3-immunoreactive (ir) neurons in the geniculate ganglion was approximately 32% at 3 days after CT injury, but these neurons were never detected in the naive ganglion. Using in situ hybridization, the mean percentage of GAP-43 mRNA-labeled neurons (signal : noise ratio > or = 10) was observed to have increased significantly to approximately 60% for 1-7 days after CT injury, while that in the naive ganglion was < 15%. The results of morphological studies using scanning electron microscopy and immunohistochemistry indicated that atrophic change and reduction of protein gene-product 9.5-ir fibers in the denervated papillae, mainly in the intragemmal region, were observed after CT injury. Increase in GAP-43 mRNA, suggesting CT axonal regeneration, may have a role in recovery from taste disorders. However, this regenerative process may be involved in abnormal activity in the axotomized neurons or the adjacent intact neurons and so one must not disregard the existence of injured geniculate ganglions when considering the treatment of diseases that cause CT injury.
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Affiliation(s)
- Kenzo Tsuzuki
- Department of Otorhinolaryngology, Hyogo College of Medicine, Japan
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Awatramani R, Shumas S, Kamholz J, Scherer SS. TGFbeta1 modulates the phenotype of Schwann cells at the transcriptional level. Mol Cell Neurosci 2002; 19:307-19. [PMID: 11906205 DOI: 10.1006/mcne.2001.1094] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have examined the effects of transforming growth factor beta1 (TGFbeta1) on gene expression in cultured rat Schwann cells (SCs). TGFbeta1 decreased the steady-state mRNA levels of several genes that are expressed by myelinating SCs but had varied effects on the mRNA levels of NCAM, L1, GAP-43, and p75-genes that are expressed by denervated and nonmyelinating SCs. TGFbeta1 antagonized the effects of forskolin on the mRNA levels of the transcription factors Oct-6/tst-1/SCIP and Krox20. Transcriptional run-off analysis demonstrated that the effects of TGFbeta1 on gene expression occur at least in part at the level of transcription. Thus, TGFbeta1 suppresses the expression of genes that characterize the different phenotypes of SCs, and these changes occur at least in part at a transcriptional level.
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Affiliation(s)
- Rajeshwar Awatramani
- Department of Neurology, Wayne State University, Elliman Building 3206, 421 East Canfield, Detroit, Michigan 48201, USA
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Zubair M, Watanabe E, Fukada M, Noda M. Genetic labelling of specific axonal pathways in the mouse central nervous system. Eur J Neurosci 2002; 15:807-14. [PMID: 11906522 DOI: 10.1046/j.1460-9568.2002.01911.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We report on transgenic mouse lines in which several sensory systems in the brain are specifically visualized genetically. We employed GAP-lacZ as an axon-targeted reporter protein that was constructed by fusing the membrane-anchoring domain of the GAP-43 protein to lacZ. The reporter gene was introduced into the genome under the control of a promoter element of Brn3b transcription factor to establish transgenic mouse lines. The individual lines thus generated afforded clear images of specific axonal pathways of the visual, vomeronasal, pontocerebellar, and auditory systems. The reporter protein labelled the entire axonal process as well as the cell body of developing and mature neurons on staining with X-gal. We show that these lines facilitate the developmental and anatomical study of these neural systems. This strategy should be applicable to a variety of neural systems by using various specific promoter elements.
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Affiliation(s)
- Mohamad Zubair
- Division of Molecular Neurobiology, National Institute for Basic Biology, Myodaiji-cho, Okazaki 444-8585, Japan
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Altun M, Bergman E, Ulfhake B. Retrograde labeling of primary sensory neurons with fluorescent latex microspheres: a useful tool for long term tagging of neurons. J Neurosci Methods 2001; 108:19-24. [PMID: 11459614 DOI: 10.1016/s0165-0270(01)00367-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study we have used fluorescent microspheres to retrogradely label primary sensory neurons in dorsal root ganglia (DRGs). Following injection into peripheral nerves, the animals were allowed to survive up to 480 days. Simple profile count indicates that there is a substantial retention of the labeling still after at least 480 days, i.e. about two-thirds of a rat's life span. Moreover, the appearance of the labeling remains quite distinct. Using established markers for axon damage of DRG neurons, we could detect a slight and transient effect of the peripheral nerve injection on the gene expression pattern. It is concluded that fluorescent microspheres represents an attractive means of tagging neurons in experiments covering long time periods.
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Affiliation(s)
- M Altun
- Experimental Neurogerontology, Department of Neuroscience, Karolinska Institutet, Nobelsv 12 17177 Stockholm, Sweden
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