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Murugesan A, Konda Mani S, Koochakkhani S, Subramanian K, Kandhavelu J, Thiyagarajan R, Gurbanov AV, Mahmudov KT, Kandhavelu M. Design, synthesis and anticancer evaluation of novel arylhydrazones of active methylene compounds. Int J Biol Macromol 2024; 254:127909. [PMID: 37951450 DOI: 10.1016/j.ijbiomac.2023.127909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023]
Abstract
Nerve growth factor (NGF) and its receptor, tropomyosin kinase receptor kinase type A (TrkA) is emerging as an important target for Glioblastoma (GBM) treatment. TrkA is the cancer biomarker majorly involved in tumor invasion and migration into nearby normal tissue. However, currently, available Trk inhibitors exhibit many adverse effects in cancer patients, thus demanding a novel class of ligands to regulate Trk signaling. Here, we exploited the role of TrkA (NTRK1) expression from the 651 datasets of brain tumors. RNA sequence analysis identified overexpression of NTRK1 in GBM, recurrent GBM as well in Oligoastrocytoma patients. Also, TrkA expression tends to increase over the higher grades of GBM. TrkA protein targeting hydrazone derivatives, R48, R142, and R234, were designed and their mode of interaction was studied using molecular docking and dynamic simulation studies. Ligands' stability and binding assessment reveals R48, 2 2-(2-(2-hydroxy-4-nitrophenyl) hydrazineylidene)-1-phenylbutane-1,3-dione, as a potent ligand that interacts well with TrkA's hydrophobic residues, Ile, Phe, Leu, Ala, and Val. R48- TrkA exhibits stable binding potentials with an average RMSD value <0.8 nm. R48 obeyed Lipinski's rule of five and possessed the best oral bioavailability, suggesting R48 as a potential compound with drug-likeness properties. In-vitro analysis also revealed that R48 exhibited a higher cytotoxicity effect for U87 GBM cells than TMZ with the IC50 value of 68.99 μM. It showed the lowest percentage of cytotoxicity to the non-cancerous TrkA expressing MEF cells. However, further SiRNA analysis validates the non-specific binding of R48, necessitating structural alteration for the development of R48-based TrkA inhibitor for GBM therapeutics.
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Affiliation(s)
- Akshaya Murugesan
- Department of Biotechnology, Lady Doak College, Madurai Kamaraj University, Thallakulam, Madurai 625002, India; Molecular Signaling Group, Faculty of Medicine and Health Technology, Tampere University and BioMediTech, P.O. Box 553, 33101 Tampere, Finland
| | - Saravanan Konda Mani
- Department of Biotechnology, Bharath Institute of Higher Education & Research, Chennai 600 073, Tamilnadu, India
| | - Shabnaz Koochakkhani
- Molecular Signaling Group, Faculty of Medicine and Health Technology, Tampere University and BioMediTech, P.O. Box 553, 33101 Tampere, Finland
| | - Kumar Subramanian
- Oncology Division, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Johannesburg, South Africa
| | - Jayalakshmi Kandhavelu
- Oncology Division, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Johannesburg, South Africa
| | - Ramesh Thiyagarajan
- Department of Basic Medical Sciences, College of Medicine, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Atash V Gurbanov
- Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Excellence Center, Baku State University, Z. Xalilov Str. 23, Az 1148 Baku, Azerbaijan
| | - Kamran T Mahmudov
- Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Excellence Center, Baku State University, Z. Xalilov Str. 23, Az 1148 Baku, Azerbaijan
| | - Meenakshisundaram Kandhavelu
- Molecular Signaling Group, Faculty of Medicine and Health Technology, Tampere University and BioMediTech, P.O. Box 553, 33101 Tampere, Finland.
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Fanfarillo F, Ferraguti G, Lucarelli M, Francati S, Barbato C, Minni A, Ceccanti M, Tarani L, Petrella C, Fiore M. The Impact of ROS and NGF in the Gliomagenesis and their Emerging Implications in the Glioma Treatment. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:449-462. [PMID: 37016521 DOI: 10.2174/1871527322666230403105438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 12/19/2022] [Accepted: 02/01/2023] [Indexed: 04/06/2023]
Abstract
Reactive oxygen species (ROS) are highly reactive molecules derived from molecular oxygen (O2). ROS sources can be endogenous, such as cellular organelles and inflammatory cells, or exogenous, such as ionizing radiation, alcohol, food, tobacco, chemotherapeutical agents and infectious agents. Oxidative stress results in damage of several cellular structures (lipids, proteins, lipoproteins, and DNA) and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging. A large body of studies showed that ROS plays an important role in carcinogenesis. Indeed, increased production of ROS causes accumulation in DNA damage leading to tumorigenesis. Various investigations demonstrated the involvement of ROS in gliomagenesis. The most common type of primary intracranial tumor in adults is represented by glioma. Furthermore, there is growing attention on the role of the Nerve Growth Factor (NGF) in brain tumor pathogenesis. NGF is a growth factor belonging to the family of neurotrophins. It is involved in neuronal differentiation, proliferation and survival. Studies were conducted to investigate NGF pathogenesis's role as a pro- or anti-tumoral factor in brain tumors. It has been observed that NGF can induce both differentiation and proliferation in cells. The involvement of NGF in the pathogenesis of brain tumors leads to the hypothesis of a possible implication of NGF in new therapeutic strategies. Recent studies have focused on the role of neurotrophin receptors as potential targets in glioma therapy. This review provides an updated overview of the role of ROS and NGF in gliomagenesis and their emerging role in glioma treatment.
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Affiliation(s)
| | - Giampiero Ferraguti
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Marco Lucarelli
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Silvia Francati
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | | | - Antonio Minni
- Department of Sensory Organs, Sapienza University of Rome, Rome, Italy
| | - Mauro Ceccanti
- SITAC, Società Italiana per il Trattamento dell'Alcolismo e le sue Complicanze, Rome, Italy
| | - Luigi Tarani
- Department of Maternal Infantile and Urological Sciences, Sapienza University of Rome, Rome, Italy
| | - Carla Petrella
- Institute of Biochemistry and Cell Biology, IBBC-CNR, Rome, Italy
| | - Marco Fiore
- Institute of Biochemistry and Cell Biology, IBBC-CNR, Rome, Italy
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3
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Lee TH, Yoon DH, Park KJ, Hong SM, Kim M, Kim SY, Kim CS, Lee KR. Neurotrophic phenolic glycosides from the roots of Armoracia rusticana. PHYTOCHEMISTRY 2023; 216:113886. [PMID: 37806466 DOI: 10.1016/j.phytochem.2023.113886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 10/01/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Armoracia rusticana P. G. Gaertner. belongs to the Brassicaceae family and has aroused scientific interest for its anti-inflammatory and anticancer activities. In a continuing investigation to discover bioactive constituents from A. rusticana, we isolated 19 phenolic glycosides including three undescribed flavonol glycosides and one undescribed neolignan glycoside from MeOH extract of this plant. Their structures were elucidated based on NMR spectroscopic analysis (1H, 13C, 1H-1H COSY, HSQC, and HMBC), HRESIMS, and chemical methods. The determination of their absolute configuration was accomplished by ECD and LC-MS analysis. All the compounds were assessed for their potential neurotrophic activity through induction of nerve growth factor in C6 glioma cell lines and for their anti-neuroinflammatory activity based on the measurement of inhibition levels of nitric oxide production and pro-inflammatory cytokines (i.e., IL-1β, IL-6, and TNF-α) in lipopolysaccharide-activated microglia BV-2 cells.
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Affiliation(s)
- Tae Hyun Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea; Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Da Hye Yoon
- Gachon Institute of Pharmaceutical Science, Gachon University, Incheon, 21936, Republic of Korea; College of Pharmacy, Gachon University, #191, Hambakmoero, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Kyoung Jin Park
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Seong-Min Hong
- College of Pharmacy, Gachon University, #191, Hambakmoero, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Minji Kim
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Sun Yeou Kim
- Gachon Institute of Pharmaceutical Science, Gachon University, Incheon, 21936, Republic of Korea; College of Pharmacy, Gachon University, #191, Hambakmoero, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Chung Sub Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea; Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Kang Ro Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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4
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Tiberi A, Carucci NM, Testa G, Rizzi C, Pacifico P, Borgonovo G, Arisi I, D’Onofrio M, Brandi R, Gan WB, Capsoni S, Cattaneo A. Reduced levels of NGF shift astrocytes toward a neurotoxic phenotype. Front Cell Dev Biol 2023; 11:1165125. [PMID: 37143894 PMCID: PMC10151754 DOI: 10.3389/fcell.2023.1165125] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/16/2023] [Indexed: 05/06/2023] Open
Abstract
Nerve growth factor (NGF) is critical for neuronal physiology during development and adulthood. Despite the well-recognized effect of NGF on neurons, less is known about whether NGF can actually affect other cell types in the central nervous system (CNS). In this work, we show that astrocytes are susceptible to changes in ambient levels of NGF. First, we observe that interfering with NGF signaling in vivo via the constitutive expression of an antiNGF antibody induces astrocytic atrophy. A similar asthenic phenotype is encountered in an uncleavable proNGF transgenic mouse model (TgproNGF#72), effectively increasing the brain proNGF levels. To examine whether this effect on astrocytes is cell-autonomous, we cultured wild-type primary astrocytes in the presence of antiNGF antibodies, uncovering that a short incubation period is sufficient to potently and rapidly trigger calcium oscillations. Acute induction of calcium oscillations by antiNGF antibodies is followed by progressive morphological changes similar to those observed in antiNGF AD11 mice. Conversely, incubation with mature NGF has no effect on either calcium activity nor on astrocytic morphology. At longer timescales, transcriptomic analysis revealed that NGF-deprived astrocytes acquire a proinflammatory profile. In particular, antiNGF-treated astrocytes show upregulation of neurotoxic transcripts and downregulation of neuroprotective mRNAs. Consistent with that data, culturing wild-type neurons in the presence of NGF-deprived astrocytes leads to neuronal cell death. Finally, we report that in both awake and anesthetized mice, astrocytes in layer I of the motor cortex respond with an increase in calcium activity to acute NGF inhibition using either NGF-neutralizing antibodies or a TrkA-Fc NGF scavenger. Moreover, in vivo calcium imaging in the cortex of the 5xFAD neurodegeneration mouse model shows an increased level of spontaneous calcium activity in astrocytes, which is significantly reduced after acute administration of NGF. In conclusion, we unveil a novel neurotoxic mechanism driven by astrocytes, triggered by their sensing and reacting to changes in the levels of ambient NGF.
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Affiliation(s)
- Alexia Tiberi
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, United States
| | | | | | | | | | | | - Ivan Arisi
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Mara D’Onofrio
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Rossella Brandi
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
| | - Wen-Biao Gan
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, United States
- Shenzhen Bay Laboratory, Shenzhen, China
| | - Simona Capsoni
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- Institute of Physiology, Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Antonino Cattaneo
- BIO@SNS, Scuola Normale Superiore, Pisa, Italy
- European Brain Research Institute - Fondazione Rita Levi-Montalcini, Rome, Italy
- *Correspondence: Antonino Cattaneo,
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5
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Jaudon F, Albini M, Ferroni S, Benfenati F, Cesca F. A developmental stage- and Kidins220-dependent switch in astrocyte responsiveness to brain-derived neurotrophic factor. J Cell Sci 2021; 134:jcs258419. [PMID: 34279618 DOI: 10.1242/jcs.258419] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022] Open
Abstract
Astroglial cells are key to maintain nervous system homeostasis. Neurotrophins are known for their pleiotropic effects on neuronal physiology but also exert complex functions to glial cells. Here, we investigated (i) the signaling competence of mouse embryonic and postnatal primary cortical astrocytes exposed to brain-derived neurotrophic factor (BDNF) and, (ii) the role of kinase D-interacting substrate of 220 kDa (Kidins220), a transmembrane scaffold protein that mediates neurotrophin signaling in neurons. We found a shift from a kinase-based response in embryonic cells to a response predominantly relying on intracellular Ca2+ transients [Ca2+]i within postnatal cultures, associated with a decrease in the synthesis of full-length BDNF receptor TrkB, with Kidins220 contributing to the BDNF-activated kinase and [Ca2+]i pathways. Finally, Kidins220 participates in the homeostatic function of astrocytes by controlling the expression of the ATP-sensitive inward rectifier potassium channel 10 (Kir4.1) and the metabolic balance of embryonic astrocytes. Overall, our data contribute to the understanding of the complex role played by astrocytes within the central nervous system, and identify Kidins220 as a novel actor in the increasing number of pathologies characterized by astrocytic dysfunctions. This article has an associated First Person interview with the first authors of the paper.
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Affiliation(s)
- Fanny Jaudon
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Martina Albini
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
- Department of Experimental Medicine, University of Genova, 16132 Genova, Italy
| | - Stefano Ferroni
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
- IRCCS Ospedale Policlinico San Martino, 16132 Genova, Italy
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
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6
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Shieh P, Jan CR, Liang WZ. The protective effects of the antioxidant N-acetylcysteine (NAC) against oxidative stress-associated apoptosis evoked by the organophosphorus insecticide malathion in normal human astrocytes. Toxicology 2019; 417:1-14. [PMID: 30769050 DOI: 10.1016/j.tox.2019.02.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 01/23/2019] [Accepted: 02/09/2019] [Indexed: 12/21/2022]
Abstract
Malathion is one of the most widely used organophosphorus insecticides in agriculture. However, malathion may be involved in the etiology of human brain dysfunction. Induction of ROS has been proposed as a mechanism of malathion-induced poisoning cases, but there are few data regarding the effects of malathion on oxidative stress-associated neurotoxicity in human glial cells. The aim was to explore the mechanism underlying effects of malathion on neurotoxicity in Gibco® Human Astrocytes (GHA cells) and evaluate the protective effects of the antioxidant (N-acetylcysteine, NAC). Cell viability was measured by the cell proliferation reagent (WST-1). Antioxidant enzymes (glutathione peroxidase and catalase) were measured by an ELISA reader. Cell cycle distribution and ROS productions were detected by flow cytometry. Cell cycle-related protein levels (cyclin E1, CDK2, cyclin A2, CDK1/CDC2, or cyclin B1) and apoptotic protein levels (Bcl-2, Bax, and cleaved caspase-9/caspase-3) were analyzed by Western blotting. In GHA cells, treatment with malathion (10-25 μM) for 24 h concentration-dependently induced cytotoxicity and cell cycle arrest. In terms of oxidative stresses, malathion elevated intracellular ROS levels, but reduced glutathion and antioxidant enzyme levels. Treatment with NAC (5 μM) reversed malathion-induced oxidative stress responses, and prevented malathion-evoked apoptosis by regulating apoptotic protein expressions. Together, in GHA cells, NAC mediated inhibition of malathion-activated mitochondrial apoptotic pathways that involved cell cycle arrest and ROS responses. These data provide further insights into the molecular mechanisms behind malathion poisoning, and might suggest that NAC with its protective effects may be a potential compound for prevention of malathion-induced brain injury.
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Affiliation(s)
- Pochuen Shieh
- Department of Pharmacy, Tajen University, Pingtung, 90741, Taiwan, ROC
| | - Chung-Ren Jan
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, 81362, Taiwan, ROC
| | - Wei-Zhe Liang
- Department of Pharmacy, Tajen University, Pingtung, 90741, Taiwan, ROC.
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7
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Becker K, Cana A, Baumgärtner W, Spitzbarth I. p75 Neurotrophin Receptor: A Double-Edged Sword in Pathology and Regeneration of the Central Nervous System. Vet Pathol 2018; 55:786-801. [PMID: 29940812 DOI: 10.1177/0300985818781930] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The low-affinity nerve growth factor receptor p75NTR is a major neurotrophin receptor involved in manifold and pleiotropic functions in the developing and adult central nervous system (CNS). Although known for decades, its entire functions are far from being fully elucidated. Depending on the complex interactions with other receptors and on the cellular context, p75NTR is capable of performing contradictory tasks such as mediating cell death as well as cell survival. In parallel, as a prototype marker for certain differentiation stages of Schwann cells and related CNS aldynoglial cells, p75NTR has recently gained increasing notice as a marker for cells with proposed regenerative potential in CNS diseases, such as demyelinating disease and traumatic CNS injury. Besides its pivotal role as a marker for transplantation candidate cells, recent studies in canine neuroinflammatory CNS conditions also highlight a spontaneous endogenous occurrence of p75NTR-positive glia, which potentially play a role in Schwann cell-mediated CNS remyelination. The aim of the present communication is to review the pleiotropic functions of p75NTR in the CNS with a special emphasis on its role as an immunohistochemical marker in neuropathology. Following a brief illustration of the expression of p75NTR in neurogenesis and in developed neuronal populations, the implications of p75NTR expression in astrocytes, oligodendrocytes, and microglia are addressed. A special focus is put on the role of p75NTR as a cell marker for specific differentiation stages of Schwann cells and a regeneration-promoting CNS population, collectively referred to as aldynoglia.
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Affiliation(s)
- Kathrin Becker
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Armend Cana
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
| | - Wolfgang Baumgärtner
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
| | - Ingo Spitzbarth
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
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8
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Yao R, Murtaza M, Velasquez JT, Todorovic M, Rayfield A, Ekberg J, Barton M, St John J. Olfactory Ensheathing Cells for Spinal Cord Injury: Sniffing Out the Issues. Cell Transplant 2018; 27:879-889. [PMID: 29882418 PMCID: PMC6050914 DOI: 10.1177/0963689718779353] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Olfactory ensheathing cells (OECs) are glia reported to sustain the continuous axon extension and successful topographic targeting of the olfactory receptor neurons responsible for the sense of smell (olfaction). Due to this distinctive property, OECs have been trialed in human cell transplant therapies to assist in the repair of central nervous system injuries, particularly those of the spinal cord. Though many studies have reported neurological improvement, the therapy remains inconsistent and requires further improvement. Much of this variability stems from differing olfactory cell populations prior to transplantation into the injury site. While some studies have used purified cells, others have used unpurified transplants. Although both preparations have merits and faults, the latter increases the variability between transplants received by recipients. Without a robust purification procedure in OEC transplantation therapies, the full potential of OECs for spinal cord injury may not be realised.
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Affiliation(s)
- R Yao
- 1 Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia
| | - M Murtaza
- 1 Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia.,2 Menzies Health Institute Queensland, Griffith Health Centre, Griffith University, Gold Coast, Queensland, Australia
| | - J Tello Velasquez
- 1 Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia
| | - M Todorovic
- 1 Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia.,2 Menzies Health Institute Queensland, Griffith Health Centre, Griffith University, Gold Coast, Queensland, Australia
| | - A Rayfield
- 2 Menzies Health Institute Queensland, Griffith Health Centre, Griffith University, Gold Coast, Queensland, Australia
| | - J Ekberg
- 2 Menzies Health Institute Queensland, Griffith Health Centre, Griffith University, Gold Coast, Queensland, Australia
| | - M Barton
- 2 Menzies Health Institute Queensland, Griffith Health Centre, Griffith University, Gold Coast, Queensland, Australia
| | - J St John
- 1 Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia.,2 Menzies Health Institute Queensland, Griffith Health Centre, Griffith University, Gold Coast, Queensland, Australia
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9
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Cragnolini AB, Montenegro G, Friedman WJ, Mascó DH. Brain-region specific responses of astrocytes to an in vitro injury and neurotrophins. Mol Cell Neurosci 2018; 88:240-248. [PMID: 29444457 DOI: 10.1016/j.mcn.2018.02.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 01/22/2018] [Accepted: 02/09/2018] [Indexed: 11/17/2022] Open
Abstract
Astrocytes are a heterogeneous population of glial cells that react to brain insults through a process referred to as astrogliosis. Reactive astrocytes are characterized by an increase in proliferation, size, migration to the injured zone and release of a plethora of chemical mediators such as NGF and BDNF. The aim of this study was to determine whether there are brain region-associated responses of astrocytes to an injury and to the neurotrophins NGF and BDNF. We used the scratch injury model to study the closure of a wound inflicted on a monolayer of astrocytes obtained from cortex, hippocampus or striatum. Our results indicate that the response of astrocytes to a mechanical lesion differ according to brain regions. Astrocytes from the striatum proliferate and repopulate the injury site more rapidly than astrocytes from cortex or hippocampus. We found that the scratch injury induced the upregulation of neurotrophin receptor p75NTR and TrkB.t in astrocytes from all brain regions studied. When astrocytes from all regions were treated with NGF, the neurotrophin induced migration of the astrocytes (assessed in Boyden chambers) and induced wound closure but did not affect proliferation. In contrast, BDNF induced wound closure but only in astrocytes from striatum. Our overall findings show the heterogeneity in astrocyte functions based on their brain region of origin, and how this functional diversity may determine their responses to an injury and to neurotrophins.
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Affiliation(s)
- Andrea Beatriz Cragnolini
- IIByT-UNC CONICET, CEBICEM, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 1611, X5016GCA Córdoba, Argentina
| | - Gonzalo Montenegro
- IIByT-UNC CONICET, CEBICEM, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 1611, X5016GCA Córdoba, Argentina
| | - Wilma J Friedman
- Department of Biological Sciences, Rutgers University, 225 University Avenue, Newark, N.J. 07102, United States
| | - Daniel Hugo Mascó
- IIByT-UNC CONICET, CEBICEM, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 1611, X5016GCA Córdoba, Argentina.
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10
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Ma W, Yang JW, Gao Y, Liang Z, Li XT, Wang TT, Wang XB, Liu J, Fan CM, Guo JH, Li LY. Expression pattern of high-affinity tyrosine kinase Aduring the development of human fetal spinal cord. Biotech Histochem 2017; 92:577-583. [PMID: 29264935 DOI: 10.1080/10520295.2017.1369159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
High-affinity tyrosine kinase A (TrkA) is responsible for the biological activities of nerve growth factor. Most studies of the molecular mechanisms of TrkA that underlie the development of the spinal cord have been conducted in animals and the expression pattern of TrkA during the development of the human fetal spinal cord is not well characterized. We investigated 45 3-28-week-old (G3W-G28W) human fetuses. We assessed the expression pattern of TrkA in the human fetal spinal cord using immunohistochemistry, western blot and reverse transcription polymerase chain reaction to clarify the spatiotemporal developmental changes and to determine the role TrkA plays in development. TrkA immunoreactive products were detected widely in the alar and basal plates, ependyma, glial cells, gray and white matter, internal limiting membrane, mantle layer, marginal layer, neuroepithelium and neurons during this period of development. Expression levels of TrkA mRNA and protein peaked at G12W and G16W, respectively. The strong expression of TrkA was closely related to the formation of the dorsal and ventral horns, and the differentiation of somatic motor neurons during late embryonic development. Our findings suggest that TrkA receptors play crucial roles during the development of human fetal spinal cord. The characteristic expression patterns may clarify the developmental characteristics of the human spinal cord.
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Affiliation(s)
- W Ma
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming
| | - J-W Yang
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming.,b Second Department of General Surgery , First People's Hospital of Yunnan Province , Yunnan , Kunming
| | - Y Gao
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming.,c Department of Pathology , Children's Hospital of Kunming City , Yunnan , Kunming
| | - Z Liang
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming
| | - X-T Li
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming
| | - T-T Wang
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming
| | - X-B Wang
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming
| | - J Liu
- b Second Department of General Surgery , First People's Hospital of Yunnan Province , Yunnan , Kunming
| | - C-M Fan
- d Department of Critical Care Medicine , First People's Hospital of Yunnan Province , Yunnan Kunming , China
| | - J-H Guo
- b Second Department of General Surgery , First People's Hospital of Yunnan Province , Yunnan , Kunming
| | - L-Y Li
- a Institute of Neuroscience, Basic Medical College, Kunming Medical University , Yunnan , Kunming
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11
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Coulson-Thomas VJ, Lauer ME, Soleman S, Zhao C, Hascall VC, Day AJ, Fawcett JW. Tumor Necrosis Factor-stimulated Gene-6 (TSG-6) Is Constitutively Expressed in Adult Central Nervous System (CNS) and Associated with Astrocyte-mediated Glial Scar Formation following Spinal Cord Injury. J Biol Chem 2016; 291:19939-52. [PMID: 27435674 PMCID: PMC5025681 DOI: 10.1074/jbc.m115.710673] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Indexed: 12/18/2022] Open
Abstract
Tumor necrosis factor (TNF)-stimulated gene-6 (TSG-6) binds to hyaluronan and can reorganize/stabilize its structure, also enhancing the binding of this glycosaminoglycan to its cell surface receptor, CD44. TSG-6 is rapidly up-regulated in response to inflammatory cytokines protecting tissues from the damaging effects of inflammation. Despite TSG-6 treatment having been shown to improve outcomes in an experimental model of traumatic brain injury, TSG-6 expression has not been extensively studied in the central nervous system (CNS). We hereby analyzed the expression profile of TSG-6 in the developing CNS and following injury. We show that TSG-6 is expressed in the rat CNS by GFAP(+) and CD44(+) astrocytes, solely in the mature brain and spinal cord, and is not present during the development of the CNS. TSG-6(-/-) mice present a reduced number of GFAP(+) astrocytes when compared with the littermate TSG-6(+/-) mice. TSG-6 expression is drastically up-regulated after injury, and the TSG-6 protein is present within the glial scar, potentially coordinating and stabilizing the formation of this hyaluronan-rich matrix. This study shows that TSG-6 is expressed in the CNS, suggesting a role for TSG-6 in astrocyte activation and tissue repair. We hypothesize that within this context TSG-6 could participate in the formation of the glial scar and confer anti-inflammatory properties. Further studies are required to elucidate the therapeutic potential of targeting TSG-6 after CNS injury to promote its protective effects while reducing the inhibitory properties of the glial scar in axon regeneration.
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Affiliation(s)
- Vivien J Coulson-Thomas
- From the John Van Geest Cambridge Centre for Brain Repair, The E. D. Adrian Building, Forvie Site, Robinson Way, University of Cambridge, Cambridge CB2 0PY, United Kingdom,
| | - Mark E Lauer
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio 44195
| | - Sara Soleman
- From the John Van Geest Cambridge Centre for Brain Repair, The E. D. Adrian Building, Forvie Site, Robinson Way, University of Cambridge, Cambridge CB2 0PY, United Kingdom
| | - Chao Zhao
- Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute and Department of Clinical Neurosciences, Clifford Allbutt Building, University of Cambridge, Cambridge CB2 0AH, United Kingdom, and
| | - Vincent C Hascall
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio 44195
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - James W Fawcett
- From the John Van Geest Cambridge Centre for Brain Repair, The E. D. Adrian Building, Forvie Site, Robinson Way, University of Cambridge, Cambridge CB2 0PY, United Kingdom,
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12
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Tyrosine kinome profiling: oncogenic mutations and therapeutic targeting in cancer. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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13
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Cragnolini AB, Volosin M, Huang Y, Friedman WJ. Nerve growth factor induces cell cycle arrest of astrocytes. Dev Neurobiol 2012; 72:766-76. [PMID: 21954122 DOI: 10.1002/dneu.20981] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neurotrophins can influence multiple cellular functions depending on the cellular context and the specific receptors they interact with. These neurotrophic factors have been extensively studied for their ability to support neuronal survival via Trk receptors and to induce apoptosis via the p75(NTR). However, the p75(NTR) is also detected on cell populations that do not undergo apoptosis in response to neurotrophins. In particular, the authors have detected p75(NTR) expression on astrocytes during development and after seizure-induced injury. In this study, the authors investigated the role of Nerve growth factor (NGF) in regulating astrocyte proliferation and in influencing specific aspects of the cell cycle. The authors have demonstrated that NGF prevents the induction of cyclins and their association with specific cyclin-dependent kinases, and thereby prevents progression through the G1 phase of the cell cycle. Since the authors have previously shown that p75(NTR) but not TrkA, is expressed in astrocytes, these data suggest that activation of p75(NTR) promotes withdrawal of astrocytes from the cell cycle, which may have important consequences during development and after injury.
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Affiliation(s)
- Andrea B Cragnolini
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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14
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Schachtrup C, Le Moan N, Passino MA, Akassoglou K. Hepatic stellate cells and astrocytes: Stars of scar formation and tissue repair. Cell Cycle 2011; 10:1764-71. [PMID: 21555919 DOI: 10.4161/cc.10.11.15828] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Scar formation inhibits tissue repair and regeneration in the liver and central nervous system. Activation of hepatic stellate cells (HSCs) after liver injury or of astrocytes after nervous system damage is considered to drive scar formation. HSCs are the fibrotic cells of the liver, as they undergo activation and acquire fibrogenic properties after liver injury. HSC activation has been compared to reactive gliosis of astrocytes, which acquire a reactive phenotype and contribute to scar formation after nervous system injury, much like HSCs after liver injury. It is intriguing that a wide range of neuroglia-related molecules are expressed by HSCs. We identified an unexpected role for the p75 neurotrophin receptor in regulating HSC activation and liver repair. Here we discuss the molecular mechanisms that regulate HSC activation and reactive gliosis and their contributions to scar formation and tissue repair. Juxtaposing key mechanistic and functional similarities in HSC and astrocyte activation might provide novel insight into liver regeneration and nervous system repair.
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15
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Roesler R, Brunetto AT, Abujamra AL, de Farias CB, Brunetto AL, Schwartsmann G. Current and emerging molecular targets in glioma. Expert Rev Anticancer Ther 2011; 10:1735-51. [PMID: 21080801 DOI: 10.1586/era.10.167] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Gliomas are the most common and lethal neurological cancers. Despite research efforts, the prognosis for patients with malignant gliomas remains poor. Advances in the understanding of cellular and molecular alterations in gliomas have led to the emergence of experimental molecularly targeted therapies. This article summarizes recent progress in the development of targeted therapies for glioma, focusing on emerging molecular targets, including neuropeptide and neurotrophin pathways, glutamate receptors, epigenetic mechanisms and glioma stem cell targets. Recent clinical trials of small molecules and antibodies targeted at growth factor pathways and intracellular signaling cascades are also discussed.
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Affiliation(s)
- Rafael Roesler
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90050-170 Porto Alegre, RS, Brazil.
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16
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Cragnolini AB, Huang Y, Gokina P, Friedman WJ. Nerve growth factor attenuates proliferation of astrocytes via the p75 neurotrophin receptor. Glia 2009; 57:1386-92. [PMID: 19229990 DOI: 10.1002/glia.20857] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The p75 neurotrophin receptor has been implicated in the regulation of multiple cellular functions that differ depending on the cell context. We have observed that p75(NTR) is strongly induced on astrocytes as well as neurons in the hippocampal CA3 region after seizures; however, the function of this receptor on these glial cells has not been defined. We have employed a primary culture system to investigate the effects of neurotrophins on astrocytes. Treatment of hippocampal astrocytes with nerve growth factor (NGF) caused a reduction in cell number, but did not elicit an apoptotic response, in contrast to hippocampal neurons. Instead, activation of p75(NTR) by NGF attenuated proliferation induced by mitogens such as EGF or serum. These studies demonstrate the cell type specificity of neurotrophin functions in the brain.
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Affiliation(s)
- Andrea B Cragnolini
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
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17
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Cragnolini AB, Friedman WJ. The function of p75NTR in glia. Trends Neurosci 2008; 31:99-104. [PMID: 18199491 DOI: 10.1016/j.tins.2007.11.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 11/20/2007] [Accepted: 11/21/2007] [Indexed: 11/19/2022]
Abstract
The p75 neurotrophin receptor (p75(NTR)) is expressed on many cell types and can influence a variety of cellular functions. This receptor can mediate cell survival or cell death, can promote or inhibit axonal growth and can facilitate or attenuate proliferation, depending on the cell context. The emerging picture regarding p75(NTR) indicates that it can partner with different coreceptors to dictate specific responses. It then signals by recruiting intracellular binding proteins to activate different signaling pathways. The function of p75(NTR) has mainly been studied in neurons; however, it is also expressed in a variety of glial populations, especially during development and after injury, where its roles have been poorly defined. In this review, we will examine the potential roles for p75(NTR) in glial function.
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Affiliation(s)
- Andrea B Cragnolini
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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18
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Hansen K, Wagner B, Hamel W, Schweizer M, Haag F, Westphal M, Lamszus K. Autophagic cell death induced by TrkA receptor activation in human glioblastoma cells. J Neurochem 2007; 103:259-75. [PMID: 17635673 DOI: 10.1111/j.1471-4159.2007.04753.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The neurotrophin receptor tropomyosin-related kinase A (TrkA) and its ligand nerve growth factor (NGF) are expressed in astrocytomas, and an inverse association of TrkA expression with malignancy grade was described. We hypothesized that TrkA expression might confer a growth disadvantage to glioblastoma cells. To analyze TrkA function and signaling, we transfected human TrkA cDNA into the human glioblastoma cell line G55. We obtained three stable clones, all of which responded with striking cytoplasmic vacuolation and subsequent cell death to NGF. Analyzing the mechanism of cell death, we could exclude apoptosis and cellular senescence. Instead, we identified several indications of autophagy: electron microscopy showed typical autophagic vacuoles; acridine orange staining revealed acidic vesicular organelles; acidification of acidic vesicular organelles was prevented using bafilomycin A1; cells displayed arrest in G2/M; increased processing of LC3 occurred; vacuolation was prevented by the autophagy inhibitor 3-methyladenine; no caspase activation was detected. We further found that both activation of ERK and c-Jun N-terminal kinase but not p38 were involved in autophagic vacuolation. To conclude, we identified autophagy as a novel mechanism of NGF-induced cell death. Our findings suggest that TrkA activation in human glioblastomas might be beneficial therapeutically, especially as several of the currently used chemotherapeutics also induce autophagic cell death.
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Affiliation(s)
- Katharina Hansen
- Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Martinistrasse, Hamburg, Germany
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19
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Di Loreto S, D'Angelo B, D'Amico MA, Benedetti E, Cristiano L, Cinque B, Cifone MG, Cerù MP, Festuccia C, Cimini A. PPARbeta agonists trigger neuronal differentiation in the human neuroblastoma cell line SH-SY5Y. J Cell Physiol 2007; 211:837-47. [PMID: 17390299 DOI: 10.1002/jcp.20996] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Neuroblastomas are pediatric tumors originating from immature neuroblasts in the developing peripheral nervous system. Differentiation therapies could help lowering the high mortality due to rapid tumor progression to advanced stages. Oleic acid has been demonstrated to promote neuronal differentiation in neuronal cultures. Herein we report on the effects of oleic acid and of a specific synthetic PPARbeta agonist on cell growth, expression of differentiation markers and on parameters responsible for the malignancy such as adhesion, migration, invasiveness, BDNF, and TrkB expression of SH-SY5Y neuroblastoma cells. The results obtained demonstrate that many, but not all, oleic acid effects are mediated by PPARbeta and support a role for PPARbeta in neuronal differentiation strongly pointing towards PPAR ligands as new therapeutic strategies against progression and recurrences of neuroblastoma.
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20
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Benfenati V, Caprini M, Nobile M, Rapisarda C, Ferroni S. Guanosine promotes the up-regulation of inward rectifier potassium current mediated by Kir4.1 in cultured rat cortical astrocytes. J Neurochem 2006; 98:430-45. [PMID: 16805837 DOI: 10.1111/j.1471-4159.2006.03877.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Guanosine (Guo) is an endogenous neuroprotective molecule of the CNS, which has various acute and long-term effects on both neurones and astroglial cells. Whether Guo also modulates the activity/expression of ion channels involved in homeostatic control of extracellular potassium by the astrocytic syncytium is still unknown. Here we provide electrophysiological evidence that chronic exposure (48 h) to Guo (500 microm) promotes the functional expression of an inward rectifier K+ (Kir) conductance in primary cultured rat cortical astrocytes. Molecular screening indicated that Guo promotes the up-regulation of the Kir4.1 channel, the major component of the Kir current in astroglia in vivo. Furthermore, the properties of astrocytic Kir current overlapped those of the recombinant Kir4.1 channel expressed in a heterologous system, strongly suggesting that the Guo-induced Kir conductance is mainly gated by Kir4.1. In contrast, the expression levels of two other Kir channel proteins were either unchanged (Kir2.1) or decreased (Kir5.1). Finally, we showed that inhibition of translational process, but not depression of transcription, prevents the Guo-induced up-regulation of Kir4.1, indicating that this nucleoside acts through de novo protein synthesis. Because accumulating data indicate that down-regulation of astroglial Kir current contributes to the pathogenesis of neurodegenerative diseases associated with dysregulation of extracellular K+ homeostasis, these results support the notion that Guo might be a molecule of therapeutic interest for counteracting the detrimental effect of K+-buffering impairment of the astroglial syncytium that occurs in pathological conditions.
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Affiliation(s)
- Valentina Benfenati
- Department of Human and General Physiology, University of Bologna, Bologna, Italy
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21
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Zhang HT, Li LY, Zou XL, Song XB, Hu YL, Feng ZT, Wang TTH. Immunohistochemical distribution of NGF, BDNF, NT-3, and NT-4 in adult rhesus monkey brains. J Histochem Cytochem 2006; 55:1-19. [PMID: 16899765 DOI: 10.1369/jhc.6a6952.2006] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Immunohistochemical distribution and cellular localization of neurotrophins was investigated in adult monkey brains using antisera against nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4). Western blot analysis showed that each antibody specifically recognized appropriate bands of approximately 14.7 kDa, 14.2 kDa, 13.6 kDa, and 14.5 kDa, for NGF, BDNF, NT-3, and NT-4, respectively. These positions coincided with the molecular masses of the neurotrophins studied. Furthermore, sections exposed to primary antiserum preadsorbed with full-length NGF, BDNF, NT-3, and NT-4 exhibited no detectable immunoreactivity, demonstrating specificities of the antibodies against the tissues prepared from rhesus monkeys. The study provided a systematic report on the distribution of NGF, BDNF, NT-3, and NT-4 in the monkey brain. Varying intensity of immunostaining was observed in the somata and processes of a wide variety of neurons and glial cells in the cerebrum, cerebellum, hippocampus, and other regions of the brain. Neurons in some regions such as the cerebral cortex and the hippocampus, which stained for neurotrophins, also expressed neurotrophic factor mRNA. In some other brain regions, there was discrepancy of protein distribution and mRNA expression reported previously, indicating a retrograde or anterograde action mode of neurotrophins. Results of this study provide a morphological basis for the elucidation of the roles of NGF, BDNF, NT-3, and NT-4 in adult primate brains.
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Affiliation(s)
- Hong-Tian Zhang
- Institute for Research on Neuroscience, Kunming Medical College, Kunming, China
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22
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Revuelta M, Castaño A, Machado A, Cano J, Venero JL. Kainate-induced zinc translocation from presynaptic terminals causes neuronal and astroglial cell death and mRNA loss of BDNF receptors in the hippocampal formation and amygdala. J Neurosci Res 2005; 82:184-95. [PMID: 16175575 DOI: 10.1002/jnr.20632] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To evaluate the potential role of endogenous zinc in the pathophysiology of epilepsy, we injected kainic acid into the medial septum, which evokes seizure activity and delayed hippocampal degeneration. Different approaches were used. In the hippocampus, we found a movement of zinc from the synaptic compartment to CA1 pyramidal neurons and astrocytes after kainate. The same was true in the amygdala. We found that in those areas showing intense zinc bleaching there was also a loss of reactive astrocytes, which supports the view that release of synaptic zinc induces astrocytic cell death. We have also tested whether the kainate-induced zinc movement from the synaptic compartment to neuronal or glial cells alters the expression of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, trkB. There was a prominent loss of expression of trkB mRNA in areas that coincided precisely with those displaying astrocyte loss and zinc bleaching. In the amygdala, these events were accompanied by a high upregulation of BDNF mRNA. To demonstrate further a role of synaptic zinc in hippocampal pathology, we used two different approaches. We first injected different doses of zinc chloride in the CA1 area. At lower doses (0.1-10 nmol), zinc chloride selectively induced apoptosis in CA1 pyramidal neurons and dentate granular neurons. In a second approach, we found that hippocampal zinc chelation was effective in protecting CA1 pyramidal neurons against kainate-induced cell death.
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Affiliation(s)
- Mati Revuelta
- Departamento de Bioquímica, Bromatología y Toxicología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
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23
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Lázár J, Szabó T, Marincsák R, Kovács L, Blumberg PM, Bíró T. Sensitization of recombinant vanilloid receptor-1 by various neurotrophic factors. Life Sci 2004; 75:153-63. [PMID: 15120568 DOI: 10.1016/j.lfs.2003.11.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2003] [Accepted: 11/10/2003] [Indexed: 12/31/2022]
Abstract
The vanilloid receptor (VR1) is a central integrator molecule of nociceptive stimuli. In this study, we have measured the effects of various neurotrophins (nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and -4) on recombinant rat VR1-mediated intracellular calcium rise in response to capsaicin in VR1/C6 cells. Our results clearly show that all neurotrophins sensitize the VR1 to capsaicin. Furthermore, using K252a, an inhibitor of tyrosine kinases, we present that actions of neurotrophins are mediated by the trk (A, B, C) receptors expressed in these cells. These data argue for the putative roles of neurotrophins in inducing inflammatory (thermal) hyperalgesia via VR1.
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Affiliation(s)
- József Lázár
- Department of Physiology and Cell Physiology Research Group of the Hungarian Academy of Sciences, H-4012 Debrecen, Nagyerdei krt. 98. PO Box 22, Hungary
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24
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Dubreuil CI, Winton MJ, McKerracher L. Rho activation patterns after spinal cord injury and the role of activated Rho in apoptosis in the central nervous system. J Cell Biol 2003; 162:233-43. [PMID: 12860969 PMCID: PMC2172802 DOI: 10.1083/jcb.200301080] [Citation(s) in RCA: 318] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Growth inhibitory proteins in the central nervous system (CNS) block axon growth and regeneration by signaling to Rho, an intracellular GTPase. It is not known how CNS trauma affects the expression and activation of RhoA. Here we detect GTP-bound RhoA in spinal cord homogenates and report that spinal cord injury (SCI) in both rats and mice activates RhoA over 10-fold in the absence of changes in RhoA expression. In situ Rho-GTP detection revealed that both neurons and glial cells showed Rho activation at SCI lesion sites. Application of a Rho antagonist (C3-05) reversed Rho activation and reduced the number of TUNEL-labeled cells by approximately 50% in both injured mouse and rat, showing a role for activated Rho in cell death after CNS injury. Next, we examined the role of the p75 neurotrophin receptor (p75NTR) in Rho signaling. After SCI, an up-regulation of p75NTR was detected by Western blot and observed in both neurons and glia. Treatment with C3-05 blocked the increase in p75NTR expression. Experiments with p75NTR-null mutant mice showed that immediate Rho activation after SCI is p75NTR dependent. Our results indicate that blocking overactivation of Rho after SCI protects cells from p75NTR-dependent apoptosis.
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Affiliation(s)
- Catherine I Dubreuil
- Département de pathologie et biologie cellulaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
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25
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Wadhwa S, Nag TC, Jindal A, Kushwaha R, Mahapatra AK, Sarkar C. Expression of the neurotrophin receptors Trk A and Trk B in adult human astrocytoma and glioblastoma. J Biosci 2003; 28:181-8. [PMID: 12711810 DOI: 10.1007/bf02706217] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Neurotrophins and their receptors of the Trk family play a critical role in proliferation, differentiation and survival of the developing neurons. There are reports on their expression in neoplasms too, namely, the primitive neuroectodermal tumours of childhood, and in adult astrocytic gliomas. The involvement of Trk receptors in tumour pathogenesis, if any, is not known. With this end in view, the present study has examined 10 tumour biopsy samples (identified as astrocytoma, pilocytic astrocytoma and glioblastoma) and peritumoral brain tissue of adult patients, for the presence of Trk A and Trk B receptors, by immunohistochemistry. The nature of the tumour samples was also confirmed by their immunoreactivity (IR) to glial fibrillary acidic protein. In the peritumoral brain tissue, only neurons showed IR for Trk A and Trk B. On the contrary, in the tumour sections, the IR to both receptors was localized in the vast majority of glia and capillary endothelium. There was an obvious pattern of IR in these gliomas: high levels of IR were present in the low-grade (type I and II) astrocytoma; whereas in the advanced malignant forms (WHO grade IV giant cell glioblastoma and glioblastoma multiforme) the IR was very weak. These findings suggest that Trk A and Trk B are involved in tumour pathogenesis, especially in the early stage, and may respond to signals that elicit glial proliferation, and thus contribute to progression towards malignancy.
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Affiliation(s)
- Shashi Wadhwa
- Department of Anatomy, CN Center, All India Institute of Medical Sciences, New Delhi 110 029, India.
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26
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Ruiz-Ederra J, Hitchcock PF, Vecino E. Two classes of astrocytes in the adult human and pig retina in terms of their expression of high affinity NGF receptor (TrkA). Neurosci Lett 2003; 337:127-30. [PMID: 12536040 DOI: 10.1016/s0304-3940(02)01322-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Astrocytes have been implicated in axon guidance and synaptic regeneration in the retina and these processes involve activation of the high affinity nerve growth factor receptor, known as the tyrosine kinase A (TrkA) receptor. The purpose of the present study was to characterize the expression of TrkA in astrocytes of the adult pig and human retina. To this end, sections of human and pig retinas were immunolabeled with a combination of antibodies to glial fibrillary acidic protein (GFAP) and TrkA. Our study revealed that most of the GFAP-positive cells express TrkA, whereas a rare, novel subpopulation of astrocytes was found to be devoid of TrkA. Our results support the idea that astrocytes play an important neurotrophic role in the retina.
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Affiliation(s)
- Javier Ruiz-Ederra
- Departamento de Biología Celular e Histología, Facultad de Medicina y Odontología, Universidad del País Vasco, E-48940., Leioa, Spain
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27
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Sayer FT, Oudega M, Hagg T. Neurotrophins reduce degeneration of injured ascending sensory and corticospinal motor axons in adult rat spinal cord. Exp Neurol 2002; 175:282-96. [PMID: 12009779 DOI: 10.1006/exnr.2002.7901] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Spinal cord regeneration in adult mammals is limited by neurite outgrowth inhibitors and insufficient availability of outgrowth-promoting agents. Formation of degenerative swellings at the proximal ends of severed axons (terminal clubs), which starts early after injury, also may hinder recovery and their rupture may contribute to secondary spinal cord damage. We investigated whether neurotrophins would reduce these degenerative processes. Adult rats received a transection of the dorsal column sensory and corticospinal motor tracts at T9 and anterograde tracing of the axons from the sciatic nerve and motor cortex, respectively. The highest number of terminal clubs was found at 1 day and approximately half remained present until at least 28 days. A single injection immediately after injury of a mixture of nerve growth factor, brain-derived neurotrophic factor and neurotrophin-3 into the lesion site, reduced the number of terminal clubs in the sensory system by approximately half at 1 and 7 days (but not 14) after the lesion. Individual or combinations of two neurotrophins were as effective, suggesting that the neurotrophins protected similar axonal populations. The injected neurotrophins did not affect degeneration of corticospinal motor axons. A 7-day continuous intrathecal infusion of neurotrophin-3 was more effective and also reduced terminal club formation of corticospinal axons by approximately 60%. Spinal tissue loss was not affected by the neurotrophin treatments, suggesting that terminal clubs are not major contributors to the pathogenesis of secondary spinal degeneration during the first two weeks. Thus, neurotrophins can reduce axonal degeneration in the spinal cord after traumatic axonal injury.
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Affiliation(s)
- Faisal T Sayer
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Kentucky 40292, USA
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28
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Weis C, Wiesenhofer B, Humpel C. Nerve growth factor plays a divergent role in mediating growth of rat C6 glioma cells via binding to the p75 neurotrophin receptor. J Neurooncol 2002; 56:59-67. [PMID: 11949828 DOI: 10.1023/a:1014410519935] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Dysregulation of proliferation, differentiation and cell death play a major role in glial tumors, and there is evidence for regulatory mechanisms involving nerve growth factor (NGF) and its receptors in various CNS-derived tumor cell lines. The aim of our study was to observe the effect of exogenous recombinant NGF on C6 rat glioma growth, to characterize the role of endogenous NGF and the p75 neurotrophin receptor (p75) and to rule out whether p75 is necessary to mediate the effect of exogenous NGF. Recombinant exogenous NGF (1-100 ng/ml) was applied under different serum conditions (0%, 1%, 5%) and knockdown of endogenous NGF and p75 was achieved by lipid-mediated antisense oligonucleotide treatment. In presence of serum, NGF had a positive whereas in absence of serum NGF produced a negative effect on C6 cell number. A knockdown of NGF or p75 increased cell numbers and enhanced BrdU incorporation. In p75-knocked down cells NGF did not enhance C6 glioma growth in presence of serum. We conclude that (1) exogenous recombinant NGF enhances C6 glioma growth under serum conditions but decreases cell number in absence of serum, that (2) the effect of exogenous NGF is mediated by p75 alone or by heterodimers containing p75 and that (3) either basal levels of endogenous NGF or basal levels of p75 receptor moderate C6 glioma growth and represent an autoregulatory potential of C6 glioma cells.
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Affiliation(s)
- Carla Weis
- Laboratory of Psychiatry, Clinic of Psychiatry, University Hospital Innsbruck, Austria
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Abstract
Nerve growth factor (NGF) was discovered 50 years ago as a molecule that promoted the survival and differentiation of sensory and sympathetic neurons. Its roles in neural development have been characterized extensively, but recent findings point to an unexpected diversity of NGF actions and indicate that developmental effects are only one aspect of the biology of NGF. This article considers expanded roles for NGF that are associated with the dynamically regulated production of NGF and its receptors that begins in development, extends throughout adult life and aging, and involves a surprising variety of neurons, glia, and nonneural cells. Particular attention is given to a growing body of evidence that suggests that among other roles, endogenous NGF signaling subserves neuroprotective and repair functions. The analysis points to many interesting unanswered questions and to the potential for continuing research on NGF to substantially enhance our understanding of the mechanisms and treatment of neurological disorders.
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Affiliation(s)
- M V Sofroniew
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, California 90095-1763, USA.
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Pflug BR, Colangelo AM, Tornatore C, Mocchetti I. TrkA induces differentiation but not apoptosis in C6-2B glioma cells. J Neurosci Res 2001; 64:636-45. [PMID: 11398188 DOI: 10.1002/jnr.1117] [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: 11/11/2022]
Abstract
Nerve growth factor (NGF) binds to the TrkA tyrosine kinase and the p75 neurotrophin receptors. Depending upon which receptor is activated, NGF can induce differentiation or apoptosis. C6-2B glioma cells express the p75 receptor, but NGF decreases their growth only when TrkA is introduced (C6trk). It is unclear, however, whether TrkA reduces C6-2B cell growth by apoptosis or differentiation. To examine which mechanisms account for the anti-proliferative effect of NGF in these cells, we first analyzed whether NGF causes apoptosis by flow cytometry, two-site immunoassay and in situ TUNEL. None of these methods indicated that C6trk undergo apoptosis. Additional apoptotic markers, such as Bcl-2, Bax, Bad, p53, caspase 3, and NF-kappaB were also used. C6trk cells exhibited lower levels of Bcl-2 compared with the parental C6 mock cells, but no changes in the levels of other apoptotic proteins. Moreover, NGF increased AP-1 binding activity in C6trk cells, suggesting that NGF may induce differentiation. We then examined whether TrkA changes the glioma phenotype. In C6trk cells, but not in C6mock cells, NGF enhanced the levels of neuron-specific enolase as well as the levels of A2B5 and 2', 3'-cyclic nucleotide 3'-phosphodiesterase, markers for oligodendrocytes, without affecting the expression of other neuronal markers. Our data suggest that the antiproliferative properties of TrkA may rely on its ability to induce differentiation of C6 cells from undifferentiated glioma to oligodendrocytes.
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Affiliation(s)
- B R Pflug
- Department of Neuroscience, Georgetown University, School of Medicine, Washington, DC 20007, USA
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31
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Kraft R, Basrai D, Benndorf K, Patt S. Serum deprivation and NGF induce and modulate voltage-gated Na(+) currents in human astrocytoma cell lines. Glia 2001; 34:59-67. [PMID: 11284020 DOI: 10.1002/glia.1040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glial tumor cells derived from primary tissue express large voltage-gated Na(+) currents, whereas glioma cell lines usually lack this feature. We studied the effect of serum deprivation on the expression of Na(+) currents in two astrocytoma cell lines (1321N1 and A172). Serum deprivation for more than 2 days sufficed to induce large Na(+) currents in both cell lines; 300 nM of the specific blocker of voltage-gated Na(+) channels, tetrodotoxin, blocked these currents by about 85%. During serum deprivation, the cells also underwent morphological changes that were characterized by cell rounding and outgrowth of processes. Treatment with 100 ng/ml nerve growth factor (NGF) promoted these morphological changes and also accelerated the development of Na(+) currents. In 1321N1 cells, NGF increased the Na(+) current density after short serum deprivation (3--6 d) and changed several gating properties after longer serum deprivation (9--13 d). In comparison with cells from the early culture stage (3--6 d), the steady-state inactivation of the Na(+) current was shifted by -24 mV in NGF-treated cells from the late (9--13 d) culture stage. In untreated cells, this shift was only -13 mV. NGF accelerated the kinetics of inactivation and shifted the current-voltage relationship in cells from the late culture stage by -14 mV. In A172 cells, most of these effects were present already after short serum deprivation either in presence or absence of NGF. It is concluded that in astrocytoma cells, Na(+) currents are induced by serum deprivation and are modulated by NGF. This result supports the idea that NFG controls Na(+) currents in these cells by autocrine stimulation.
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Affiliation(s)
- R Kraft
- Institute of Pathology (Neuropathology), Friedrich-Schiller University of Jena, Jena, Germany
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32
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Barker-Gibb AL, Dougherty KD, Einheber S, Drake CT, Milner TA. Hippocampal tyrosine kinase A receptors are restricted primarily to presynaptic vesicle clusters. J Comp Neurol 2001; 430:182-99. [PMID: 11135255 DOI: 10.1002/1096-9861(20010205)430:2<182::aid-cne1024>3.0.co;2-q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Adult septohippocampal cholinergic neurons are dependent on trophic support for normal functioning and survival; these effects are largely mediated by the tyrosine kinase A receptor (TrkA), which binds its ligand, nerve growth factor (NGF), with high affinity. To determine the subcellular localization of TrkA within septohippocampal terminal fields, two rabbit polyclonal antisera to the extracellular domain of TrkA were localized immunocytochemically in rat dentate gyrus by light and electron microscopy. By light microscopy, TrkA immunoreactivity was found mostly in fine, varicose fibers primarily in the hilus and, to a lesser extent, in the granule cell and molecular layers. By electron microscopy, the central and infragranular regions of the hilus contained the highest densities of TrkA-immunoreactive profiles. Most TrkA-labeled profiles were axons (31% of 3,473), axon terminals (20%), and glia (38%); fewer were dendrites (6%), dendritic spines (5%), and granule cell and interneuron somata (<1%). TrkA immunolabeling in axons and axon terminals was discrete, often concentrated in patches of small synaptic vesicles that were adjacent to somatic and dendritic profiles. TrkA-labeled terminals formed both asymmetric and symmetric synapses, primarily with dendritic shafts and spines. TrkA-immunoreactive glial profiles frequently apposed terminals contacting dendritic spines. The findings that presynaptic profiles contain TrkA immunolabeling in sites of vesicle accumulation suggest that NGF binding to TrkA may influence transmitter release. The presence of TrkA immunoreactivity in somata, dendrites, and glia further suggests that cells within the dentate gyrus may take up NGF.
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Affiliation(s)
- A L Barker-Gibb
- Department of Psychiatry and Neurology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA
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33
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Koczyk D, Oderfeld-Nowak B. Long-term microglial and astroglial activation in the hippocampus of trimethyltin-intoxicated rat: stimulation of NGF and TrkA immunoreactivities in astroglia but not in microglia. Int J Dev Neurosci 2000; 18:591-606. [PMID: 10884604 DOI: 10.1016/s0736-5748(99)00111-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the present study we investigated the microglial and astroglial response after trimethyltin (TMT) exposure over a prolonged period of time. Male Wistar rats were given a single dose of TMT (8 mg/kg, i.p.) and survived 4, 7, 21, 60 and 180 days after the administration of the toxin. Histochemistry (Griffonia simplicifolia lectin staining) and immunocytochemistry for GFAP were applied to identify micro- and astroglial cells, respectively. To assess the trophic response of glial cells (NGF and TrkA expression), single or double staining experiments were performed. In addition, the biochemical evaluation of GFAP and NGF were carried out at chosen timepoints using immunoblotting technique and ELISA, respectively. The main findings of our study were as follows. (1) A protracted activation of microglia (at least up to 2 months posttreatment). (2) A long-lasting expression of GFAP immunoreactivity (at least up to 6 months posttreatment) and a steady increase in GFAP content (at least up to 2 months posttreatment). (3) The appearance of enormously enlarged, round-shape astrocytes exclusively localized to CA1 and observed 2 months posttreatment. (4) The stimulation of NGF and TrkA expression in reactive astrocytes. (5) The strongest activation of micro- and astroglia coincided with the most prominent neurodegeneration in the hippocampus, i.e., in CA4/CA3c and CA1. It is tempting to assume that the activation of glial cells in the hippocampal areas particularly vulnerable to TMT may affect neuronal fate after neurotoxic insult.
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Affiliation(s)
- D Koczyk
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093, Warsaw, Poland
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Alderson RF, Curtis R, Alterman AL, Lindsay RM, DiStefano PS. Truncated TrkB mediates the endocytosis and release of BDNF and neurotrophin-4/5 by rat astrocytes and schwann cells in vitro. Brain Res 2000; 871:210-22. [PMID: 10899288 DOI: 10.1016/s0006-8993(00)02428-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Binding and cross-linking studies with radiolabeled neurotrophins demonstrate that cultured rat hippocampal astrocytes lack full-length TrkB, but do express high levels of truncated TrkB (tTrkB). In astrocytes and Schwann cells, tTrkB appears to have the novel function of mediating the endocytosis of neurotrophins into an acid-stable, Triton X-100 resistant intracellular pool that is released back into the medium in a temperature-dependent manner. Chloroquine treatment, trichloroacetic acid solubility, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that when incubated with astrocytes or Schwann cells for at least 48 h neither the intracellular nor the released neurotrophins were significantly degraded. The endocytosis and release of neurotrophins may represent a novel mechanism whereby neuroglia can regulate the local concentration of these neurotrophic factors for extended periods of time.
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Affiliation(s)
- R F Alderson
- Regeneron Pharmaceuticals Inc., 777 Old Saw Mill River Road, Tarrytown, NY 10591-6707, USA.
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35
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Althaus HH, Richter-Landsberg C. Glial cells as targets and producers of neurotrophins. INTERNATIONAL REVIEW OF CYTOLOGY 2000; 197:203-77. [PMID: 10761118 DOI: 10.1016/s0074-7696(00)97005-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Glial cells fulfill important tasks within the neural network of the central and peripheral nervous systems. The synthesis and secretion of various polypeptidic factors (cytokines) and a number of receptors, with which glial cells are equipped, allow them to communicate with their environment. Evidence has accumulated during recent years that neurotrophins play an important role not only for neurons but also for glial cells. This brief update of some morphological, immunocytochemical, and biochemical characteristics of glial cell lineages conveys our present knowledge about glial cells as targets and producers of neurotrophins under normal and pathological conditions. The chapter discusses the presence of neurotrophin receptors on glial cells, glial cells as producers of neurotrophins, signaling pathways downstream Trk and p75NTR, and the significance of neurotrophins and their receptors for glial cells during development, in cell death and survival, and in neurological disorders.
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Affiliation(s)
- H H Althaus
- AG Neural Regeneration, Max Planck Institute for Experimental Medicine, Göttingen, Germany
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36
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Singer HS, Hansen B, Martinie D, Karp CL. Mitogenesis in glioblastoma multiforme cell lines: a role for NGF and its TrkA receptors. J Neurooncol 2000; 45:1-8. [PMID: 10728904 DOI: 10.1023/a:1006323523437] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Neurotrophins have definitive roles in the growth/maintenance of neuronal populations, but their function in malignant gliomas is unknown. The ability for nerve growth factor (NGF) to serve as a mitogenic agent was investigated in several human glioblastoma multiforme (GBM) cell lines, including U251, U87, and U373. In a serum-free medium, the addition of NGF (200 ng/ml) to these cell lines increased cell counts over controls, after 3 days in culture by 9%, 16%, and 33%, respectively. Dose-dependent increases in cell counts and [3H]thymidine uptake were found in the more rigorously investigated U373 cell line. Proteins for both the high affinity NGF-specific tyrosine kinase binding site (p140TrkA; TrkA) and the low affinity neurotrophin (p75NTR) receptor were present in all three GBM cell lines. TrkA mRNA was identified in U373 (only cell line studied). NGF-stimulated proliferation was inhibited in a dose-dependent fashion by K252a, a blocker of Trk-induced receptor kinases. NGF, measured by ELISA, was detectable in all GBM cell lines even after 7 days of growth in serum-free medium. These data suggest that GBM cell growth can be enhanced by NGF acting via Trk receptor phosphorylation. Future studies of antiproliferative therapies should consider agents directed against intracellular Trk signaling cascades.
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Affiliation(s)
- H S Singer
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-8811, USA
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37
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Sims KD, Straff DJ, Robinson MB. Platelet-derived growth factor rapidly increases activity and cell surface expression of the EAAC1 subtype of glutamate transporter through activation of phosphatidylinositol 3-kinase. J Biol Chem 2000; 275:5228-37. [PMID: 10671571 DOI: 10.1074/jbc.275.7.5228] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Na(+)-dependent glutamate transporters are the primary mechanism for removal of excitatory amino acids (EAAs) from the extracellular space of the central nervous system and influence both physiologic and pathologic effects of these compounds. Recent evidence suggests that the activity and cell surface expression of a neuronal subtype of glutamate transporter, EAAC1, are rapidly increased by direct activation of protein kinase C and are decreased by wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-K). We hypothesized that this regulation could be analogous to insulin-induced stimulation of the GLUT4 subtype of glucose transporter, which is dependent upon activation of PI3-K. Using C6 glioma, a cell line that endogenously and selectively expresses EAAC1, we report that platelet-derived growth factor (PDGF) increased Na(+)-dependent L-[(3)H]-glutamate transport activity within 30 min. This effect of PDGF was not due to a change in total cellular EAAC1 immunoreactivity but was instead correlated with an increase cell surface expression of EAAC1, as measured using a membrane impermeant biotinylation reagent combined with Western blotting. A decrease in nonbiotinylated intracellular EAAC1 was also observed. These studies suggest that PDGF causes a redistribution of EAAC1 from an intracellular compartment to the cell surface. These effects of PDGF were accompanied by a 35-fold increase in PI3-K activity and were blocked by the PI3-K inhibitors, wortmannin and LY 294002, but not by an inhibitor of protein kinase C. Other growth factors, including insulin, nerve growth factor, and epidermal growth factor had no effect on glutamate transport nor did they increase PI3-K activity. These studies suggest that, as is observed for insulin-mediated translocation of GLUT4, EAAC1 cell surface expression can be rapidly increased by PDGF through activation of PI3-K. It is possible that this PDGF-mediated increase in EAAC1 activity may contribute to the previously demonstrated neuroprotective effects of PDGF.
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Affiliation(s)
- K D Sims
- Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Jia M, Li M, Liu XW, Jiang H, Nelson PG, Guroff G. Voltage-sensitive calcium currents are acutely increased by nerve growth factor in PC12 cells. J Neurophysiol 1999; 82:2847-52. [PMID: 10601423 DOI: 10.1152/jn.1999.82.6.2847] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Whole cell calcium currents were recorded from PC12 cells with the perforated patch technique. Currents were evoked by step depolarization from a holding potential of -90 mV. Nerve growth factor (NGF) increased calcium currents through L-type calcium channels by >75% within 3-5 min. This increase was inhibited by K-252a, by nifedipine, and by inhibition or down-regulation of kinase C. Brain-derived neurotrophic factor (BDNF) also increased calcium current, but to a smaller extent. Thus increases in calcium current can be linked to activation of either the high- or the low-affinity nerve growth factor receptor. Increases in presynaptic calcium uptake appear to be a crucial element in the short-term actions of the neurotrophins on neurotransmitter release leading to long-term potentiation. Also, the control of calcium uptake is likely to be an important factor in the long-term actions of the neurotrophins on neuronal survival and neuronal protection. The present data indicate that the PC12 cell may be a useful model for studying the effect of the neurotrophins on calcium uptake.
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Affiliation(s)
- M Jia
- Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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Nag TC, Wadhwa S. Neurotrophin receptors (Trk A, Trk B, and Trk C) in the developing and adult human retina. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1999; 117:179-89. [PMID: 10567736 DOI: 10.1016/s0165-3806(99)00121-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In this study, the ontogeny and distribution patterns of three neurotrophin receptors (Trk A, Trk B, and Trk C) were examined in the human retinas. Immunohistochemistry was performed on sections of retina and optic nerve from fetuses (11-24 weeks of gestation, wg), one infant (4-month-old) and two adult (35- and 65-years-old) subjects. At 11 wg, Trk A was expressed in the nerve fiber and inner plexiform layers, while Trk B and Trk C were expressed in many neuroblastic cells. By 16-17 wg, the photoreceptors showed immunoreactivity for all three receptors. The ganglion cell layer and amacrine cells were conspicuously immunoreactive for Trk A and Trk C, but labeled diffusely for Trk B. The horizontal cells were labeled for Trk A and Trk B. The pattern was same in the retinas at midgestation (20-21 wg). Shortly after this period, there was an apparent decrease in receptor immunoreactivity in the fetal retinas. In the infant retina, Trk A immunoreactivity was absent from horizontal cells. The photoreceptors were immunopositive for Trk B and Trk C, in infant and adult retinas. In the adults, few cells of the ganglion cell layer and inner nuclear layer were clearly labeled for Trk A and Trk C, and diffusely for Trk B. The glial cells of the retina and optic nerve immunoreacted for Trk A only, right from fetal 16 wg. The early expression of Trk B and Trk C on neuroblastic cells suggests that both play a role in cell proliferation. The developmental distribution pattern of Trk A, on the other hand, provides evidence for its involvement in differentiation of the inner plexiform layer, horizontal cells and neuroglia. The results strongly suggest that photoreceptor development is mediated by Trk receptors. The novel localization of Trk B and Trk C on adult photoreceptors points to a possible therapeutic potential for BDNF and NT-3, respectively, in photoreceptor diseases.
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Affiliation(s)
- T C Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
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40
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Differential expression of brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 in the adult rat spinal cord: regulation by the glutamate receptor agonist kainic acid. J Neurosci 1999. [PMID: 10479679 DOI: 10.1523/jneurosci.19-18-07757.1999] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Previous in vitro studies indicate that select members of the neurotrophin gene family, namely brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5), contribute to survival and differentiation of spinal cord motoneurons. To investigate the potential roles of these factors in the adult spinal cord, we examined their cellular localization and regulation after systemic exposure to an excitotoxic stimulus, kainic acid (KA). Of the neurotrophins examined, NT-4/5 mRNA was most robustly expressed in the lumbosacral spinal cord of the normal adult rat, including expression by neurons throughout the gray matter, and in a subpopulation of white and gray matter glia. Both BDNF and NT-3 mRNAs were also densely expressed by alpha motoneurons of lamina IX, but were detected at lower levels elsewhere in the gray matter. NT-3 mRNA was additionally expressed by spinal cord glia, but was less widespread compared to NT-4/5. In response to systemic administration of KA, NT-4/5 and BDNF mRNAs were dramatically upregulated in a spatially and temporally restricted fashion, whereas levels of NT-3 mRNA were unchanged. These results provide strong in vivo evidence to support the idea that BDNF, NT-3, and in particular, NT-4/5, play a role in the normal function of the adult spinal cord. Furthermore, our results indicate that the actions of BDNF and NT-4/5 participate in the response of the cord to excitotoxic stimuli, and that those of NT-4/5 and NT-3 include both neurons and glia.
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41
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Semkova I, Krieglstein J. Ciliary neurotrophic factor enhances the expression of NGF and p75 low-affinity NGF receptor in astrocytes. Brain Res 1999; 838:184-92. [PMID: 10446331 DOI: 10.1016/s0006-8993(99)01728-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A functional interactions between ciliary neurotrophic factor (CNTF) and NGF has recently been demonstrated. We found that the exposure of rat cortical astrocytes to human recombinant CNTF for 3 h increased the level of mRNA for NGF as determined by reverse transcription-polymerase chain reaction (RT-PCR). The increase in NGF message was followed by corresponding increase in NGF protein secreted from the astrocytes into the culture medium as determined 6 h later. C-fos seemed to be involved in the mechanism of NGF induction since the expression of c-fos gene preceded NGF mRNA elevation. Furthermore, we found that in cultured astrocytes exogenous CNTF increased the level of mRNA coding for p75(NTR), the low affinity receptor for NGF and other neurotrophins. CNTF is highly expressed in the lesioned brain and CNTF-induced upregulation of NGF synthesis could be involved in the endogenous repair mechanisms.
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Affiliation(s)
- I Semkova
- Center of Anatomy, Hannover Medical School, OE 4140, D-30623, Hannover, Germany.
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Honma Y, Kanazawa K, Mori T, Tanno Y, Tojo M, Kiyosawa H, Takeda J, Nikaido T, Tsukamoto T, Yokoya S, Wanaka A. Identification of a novel gene, OASIS, which encodes for a putative CREB/ATF family transcription factor in the long-term cultured astrocytes and gliotic tissue. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1999; 69:93-103. [PMID: 10350641 DOI: 10.1016/s0169-328x(99)00102-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Gliosis is a characteristic response of astrocytes to inflammation and trauma of the central nervous system (CNS). To study the mechanisms underlying gliosis, we performed differential display screening for genes specifically induced in long-term cultured astrocytes used as an in vitro gliosis model. We identified and characterized a gene (named OASIS, for old astrocyte specifically-induced substance) expressed in long-term cultured mouse astrocytes, or 'old astrocytes (OA)'. The OASIS gene encoded a putative transcription factor belonging to the cyclic AMP responsive element binding protein/activating transcription factor (CREB/ATF) gene family, with homology to box B-binding factor-2 (BBF-2), a Drosophila transcription factor. Its expression was developmentally regulated; OASIS mRNA was primarily expressed in the salivary gland and cartilage in the mouse embryo and it was transiently upregulated in the brain during postnatal two weeks. The expression became weaker in the adult brain. We also demonstrated that an expression of the OASIS mRNA was induced in response to the cryo-injury of the mouse cerebral cortex. The distribution pattern of the OASIS-positive cells in the injured cortex was very similar to that of the glial fibrillary acidic protein (GFAP)-positive cells. These results suggest that OASIS protein may play a role in gliotic events.
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Affiliation(s)
- Y Honma
- Department of Cell Science, Institute of Biomedical Sciences, 1 Hikarigaoka, Fukushima City, Fukushima 960-1295, Japan
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43
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Turner CP, Perez-Polo JR. Expression of the low affinity neurotrophin receptor, P75NGFR, in the rat forebrain, following unilateral bulbectomy. Int J Dev Neurosci 1998; 16:527-38. [PMID: 9881301 DOI: 10.1016/s0736-5748(98)00016-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been hypothesized that the main olfactory bulb, with its relatively rich source of neurotrophins, may provide trophic support for neurons that project to the bulb. We monitored expression of the common, low affinity receptor for neurotrophins, p75NGFR, in the olfactory bulb and basal forebrain of unilaterally bulbectomized and sham-treated rats, 1-16 weeks post-surgery, using the monoclonal antibody MAb192. An induction of p75NGFR-immunoreactivity was observed in both the glomerular and olfactory nerve layers of the right, contralateral main olfactory bulb of lesioned animals. The naturally occurring regeneration taking place in the olfactory neuroepithelium is known to be altered by olfactory bulbectomy, with subsequent changes in the sensory input to the remaining bulb. These changes in expression of p75NGFR in the olfactory bulb support the hypothesis we have developed in previous papers, that changes in the extent of the peripheral input from the olfactory neuroepithelium to the main olfactory bulb regulate p75NGFR expression in both the glomerular and the olfactory nerve layers. Expression of p75NGFR in the basal forebrain of bulbectomized animals was found to be no different than sham-treated controls and does not support the hypothesis that the olfactory bulb provides trophic support to this region of the central nervous system.
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Affiliation(s)
- C P Turner
- Department of Neurology 127, VA Medical Center, San Francisco, CA 94121, USA
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44
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Abstract
Cultured spinal cord neuroepithelial (NEP) cells can differentiate into neurons, oligodendrocytes and astrocytes and are morphologically and antigenically distinct from neural crest stem cells (NCSCs) that generate the PNS. NEP cells, however, can generate p75/nestin-immunoreactive cells that are morphologically and antigenically similar to previously characterized NCSCs. NEP-derived p75-immunoreactive cells differentiate into peripheral neurons, smooth muscle, and Schwann cells in mass and clonal culture. Clonal analysis of NEP cells demonstrates that a common NEP progenitor cell generated both CNS and PNS phenotypes. Differentiation into NCSCs was promoted by BMP-2/4 and differentiation did not require cells to divide, indicating that BMP played an instructive role in the differentiation process. Thus, individual NEP cells are multipotent and can differentiate into most major types of cell in the CNS and PNS and that PNS differentiation involves a transition from a NEP stem to another more limited, p75-immunoreactive, neural crest stem cell.
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Affiliation(s)
- T Mujtaba
- Department of Neurobiology and Anatomy, Department of Oncological Sciences, University of Utah Medical School, 50 North Medical Drive, Salt Lake City, Utah, 84132, USA
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45
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Gill JS, Windebank AJ. Paracrine production of nerve growth factor during rat dorsal root ganglion development. Neurosci Lett 1998; 251:149-52. [PMID: 9726365 DOI: 10.1016/s0304-3940(98)00526-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nerve growth factor is a target derived growth factor. In the peripheral nervous system, it is produced by tissues innervated by the sympathetic nervous system and small sensory neurons. In the present study, we tested the hypothesis that an alternate source of nerve growth factor must be available to support dorsal root ganglion neurons before they make connection with the target. Using reverse transcriptase polymerase chain reaction (RT-PCR), we detected nerve growth factor mRNA at embryonic day 12 to 17, but not in adult dorsal root ganglia. In situ hybridization studies revealed positive staining in satellite/supportive cells juxtaposed to dorsal root ganglion neurons. Our study suggests that nerve growth factor from supporting cells may have a paracrine function during development of primary sensory neurons.
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Affiliation(s)
- J S Gill
- Molecular Neuroscience Program, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
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Gill JS, Schenone AE, Podratz JL, Windebank AJ. Autocrine regulation of neurite outgrowth from PC12 cells by nerve growth factor. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 57:123-31. [PMID: 9630563 DOI: 10.1016/s0169-328x(98)00080-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The PC12 cell line may be used as a model of NGF-induced neuronal differentiation. Exposure to NGF is accompanied by extension of neurites, cessation of growth and differentiation into cells resembling sympathetic neurons. In this study neurite outgrowth from PC12 cells was induced in serum-free, NGF-free medium conditions. Neurite outgrowth in serum-free conditions was abolished by exposure to anti-NGF antisera. Reverse transcription combined with polymerase chain reaction (RT-PCR) and in situ hybridization of PC12 cells in serum-free medium conditions revealed NGF transcripts. Western blot analysis of these cells revealed tyrosine phosphorylation of the high affinity NGF receptor (TrkA/gp140) and activation of a downstream signal cascade element, ERK-1/MAP kinase. NGF was also detected by a specific enzyme-linked immunoabsorbant assay (ELISA) revealing picogram levels of protein in conditioned medium and cell lysates. Survival of embryonic rat dorsal root ganglion neurons was maintained in cultures grown in this serum-free conditioned medium. This demonstrated that NGF may act as an autocrine or paracrine growth factor for PC12 cell differentiation.
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Affiliation(s)
- J S Gill
- Molecular Neuroscience Program, Mayo Clinic and Mayo Foundation, 1501 Guggenheim Building, 200 First Street SW, Rochester, MN 55905, USA.
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47
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Abstract
In addition to its role as a survival factor, nerve growth factor (NGF) has been implicated in initiating apoptosis in restricted cell types both during development and after terminal cell differentiation. NGF binds to the TrkA tyrosine kinase and the p75 neurotrophin receptor, a member of the tumor necrosis factor cytokine family. To understand the mechanisms underlying survival versus death decisions, the TrkA receptor was introduced into oligodendrocyte cell cultures that undergo apoptosis in a p75-dependent manner. Here we report that activation of the TrkA NGF receptor in oligodendrocytes negates cell death by the p75 receptor. TrkA-mediated rescue from apoptosis correlated with mitogen-activated protein kinase activation. Concurrently, activation of TrkA in oligodendrocytes resulted in suppression of c-jun kinase activity initiated by p75, whereas induction of NFkappaB activity by p75 was unaffected. These results indicate that TrkA-mediated rescue involves not only activation of survival signals but also simultaneous suppression of a death signal by p75. The selective interplay between tyrosine kinase and cytokine receptors provides a novel mechanism that achieves alternative cellular responses by merging signals from different ligand-receptor systems.
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48
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Althaus HH, Hempel R, Klöppner S, Engel J, Schmidt-Schultz T, Kruska L, Heumann R. Nerve growth factor signal transduction in mature pig oligodendrocytes. J Neurosci Res 1997; 50:729-42. [PMID: 9418961 DOI: 10.1002/(sici)1097-4547(19971201)50:5<729::aid-jnr10>3.0.co;2-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It has previously been shown that nerve growth factor (NGF) is of functional significance for mature pig oligodendrocytes (OLs) in culture. The present data give evidence for the expression of TrkA, the so-called high-affinity NGF receptor, and of p75NTR, the so-called low-affinity NGF receptor. TrkA is upregulated during culturing, in contrast to the p75 receptor. Exposure of OLs to NGF induces an autophosphorylation of TrkA via its intrinsic tyrosine kinase. K-252a inhibits the TrkA autophosphorylation, which reduces the OL process formation to control levels. To the tyrosine-phosphorylated sites of TrkA several proteins, such as phospholipase C-gamma1, the adaptor protein SHC, the phosphotyrosine phosphatase SH-PTP2 (SYP) associate via their SH2 phosphotase SH-PTP2 domain. The association of SHC to TrkA is shown by co-immunoprecipitation. Indirect evidence for a possible activation of PLC-gamma1 is given by an NGF-induced increase of oligodendroglial [Ca2+]i. Downstream from TrkA, a mitogen-activated protein kinase cascade, which includes Erk1 and Erk2, is operating. An in-gel myelin basic protein kinase assay revealed that NGF activates predominantly Erk1. Finally, it is shown that NGF stimulates expression of c-fos.
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Affiliation(s)
- H H Althaus
- Max-Planck-Institute for Experimental Medicine, AG Neural Regeneration, Göttingen, Germany.
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49
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McKeon RJ, Silver J, Large TH. Expression of full-length trkB receptors by reactive astrocytes after chronic CNS injury. Exp Neurol 1997; 148:558-67. [PMID: 9417832 DOI: 10.1006/exnr.1997.6698] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Growth factors, including members of the neurotrophin family, are expressed by neuronal and glial elements following injury to the CNS. In order to assess the capacity for glial cells to respond to neurotrophins at sites of chronic injury, full-length trkB receptors were localized following implantation of a nitrocellulose filter into the cerebral cortex for 30 days. Northern analysis demonstrated that filter implants contained cells expressing transcripts for full-length and truncated trkB receptors, in contrast to the predominant expression of truncated trkB receptors by cultured astrocytes. In situ hybridization and immunohistochemistry using probes to the trkB kinase domain colocalized full-length receptors with GFAP-immunopositive reactive astrocytes adjacent to and within the filter implant. In contrast, OX-42-immunopositive microglia/macrophages were not stained for full-length trkB. These data indicate that reactive astrocytes can express functional trkB receptors following a chronic insult to the cerebral cortex and support the hypothesis that neurotrophins may regulate astrocytic responses to injury.
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Affiliation(s)
- R J McKeon
- Department of Anatomy and Cell Biology, Emory University, Atlanta, Georgia 30322, USA.
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50
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Kalyani A, Hobson K, Rao MS. Neuroepithelial stem cells from the embryonic spinal cord: isolation, characterization, and clonal analysis. Dev Biol 1997; 186:202-23. [PMID: 9205140 DOI: 10.1006/dbio.1997.8592] [Citation(s) in RCA: 235] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Adherent cultures of E10.5 rat neuroepithelial cells (NEP cells) from the caudal neural tube require FGF (fibroblast growth factor) and CEE (chick embryo extract) to proliferate and maintain an undifferentiated phenotype in culture. Epidermal growth factor (EGF) does not support E10.5 NEP cells in adherent culture and NEP cells do not form EGF-dependent neurospheres. NEP cells, however, can be grown as FGF-dependent neurospheres. NEP cells express nestin and lack all lineage-specific markers for neuronal and glial sublineages, retain their pleuripotent character over multiple passages, and can differentiate into neurons, astrocytes, and oligodendrocytes when plated on laminin in the absence of CEE. In clonal culture, NEP cells undergo self-renewal and generate colonies that vary in size from single cells to several thousand cells. With the exception of a few single-cell clones, all other NEP-derived clones contain more than one identified phenotype, with over 40% of the colonies containing A2B5, beta-111 tubulin, and GFAP-immunoreactive cells. Thus, NEP cells are multipotent and capable of generating multiple neural derivatives. NEP cells also differentiate into motoneurons immunoreactive for choline acetyl transferase (ChAT) and the low-affinity neurotrophin receptor (p75) in both mass and clonal culture. Double labeling of clones for ChAT and glial, neuronal, or oligodendrocytic lineage markers shows that motoneurons always arose in mixed cultures with other differentiated cells. Thus, NEP cells represent a common progenitor for motoneurons and other spinal cord cells. The relationship of NEP cells with other neural stem cells is discussed.
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Affiliation(s)
- A Kalyani
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City 84132, USA
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