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Jacquier A, Ribault S, Mendes M, Lacoste N, Risson V, Carras J, Latour P, Nadaj-Pakleza A, Stojkovic T, Schaeffer L. Expanding the phenotypic variability of MORC2 gene mutations: From Charcot-Marie-Tooth disease to late-onset pure motor neuropathy. Hum Mutat 2022; 43:1898-1908. [PMID: 35904125 PMCID: PMC10087860 DOI: 10.1002/humu.24445] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/09/2022] [Accepted: 07/27/2022] [Indexed: 01/25/2023]
Abstract
MORC2 gene encodes a ubiquitously expressed nuclear protein involved in chromatin remodeling, DNA repair, and transcriptional regulation. Heterozygous mutations in MORC2 gene have been associated with a spectrum of disorders affecting the peripheral nervous system such as Charcot-Marie-Tooth (CMT2Z), spinal muscular atrophy-like with or without cerebellar involvement, and a developmental syndrome associated with impaired growth, craniofacial dysmorphism and axonal neuropathy (DIGFAN syndrome). Such variability in clinical manifestations associated with the increasing number of variants of unknown significance detected by next-generation sequencing constitutes a serious diagnostic challenge. Here we report the characterization of an in vitro model to evaluate the pathogenicity of variants of unknown significance based on MORC2 overexpression in a neuroblastoma cell line SH-EP or cortical neurons. Likewise, we show that MORC2 mutants affect survival and trigger apoptosis over time in SH-EP cell line. Furthermore, overexpression in primary cortical neurons increases apoptotic cell death and decreases neurite outgrowth. Altogether, these approaches establish the pathogenicity of two new variants p.Gly444Arg and p.His446Gln in three patients from two families. These new mutations in MORC2 gene are associated with autosomal dominant CMT and with adult late onset proximal motor neuropathy, further increasing the spectrum of clinical manifestations associated with MORC2 mutations.
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Affiliation(s)
- Arnaud Jacquier
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France.,Centre de Biotechnologie Cellulaire, CBC Biotec, CHU de Lyon-HCL groupement Est, Bron, France
| | - Shams Ribault
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France.,Service de Médecine Physique et de Réadaptation, Hôpital Henry Gabrielle, Hospices Civils de Lyon, Saint-Genis-Laval, France
| | - Michel Mendes
- Service de Neurologie, Centro Hospitalar Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - Nicolas Lacoste
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France
| | - Valérie Risson
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France
| | - Julien Carras
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France.,Centre de Biotechnologie Cellulaire, CBC Biotec, CHU de Lyon-HCL groupement Est, Bron, France
| | - Philippe Latour
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France.,Unité fonctionnelle de neurogénétique moléculaire, CHU de Lyon-HCL groupement Est, Bron, France
| | - Aleksandra Nadaj-Pakleza
- Centre de Référence des maladies Neuromusculaires Nord/Est/Ile-de-France, Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Tanya Stojkovic
- Institut de Myologie, Hôpital Pitié-Salpêtrière, Paris, France
| | - Laurent Schaeffer
- PGNM, Institut NeuroMyoGène, Université Lyon1-CNRS UMR5261-INSERM U1315, Lyon, France.,Centre de Biotechnologie Cellulaire, CBC Biotec, CHU de Lyon-HCL groupement Est, Bron, France
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2
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Jacquier A, Risson V, Simonet T, Roussange F, Lacoste N, Ribault S, Carras J, Theuriet J, Girard E, Grosjean I, Le Goff L, Kröger S, Meltoranta J, Bauché S, Sternberg D, Fournier E, Kostera-Pruszczyk A, O’Connor E, Eymard B, Lochmüller H, Martinat C, Schaeffer L. Severe congenital myasthenic syndromes caused by agrin mutations affecting secretion by motoneurons. Acta Neuropathol 2022; 144:707-731. [PMID: 35948834 PMCID: PMC9468088 DOI: 10.1007/s00401-022-02475-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/25/2022] [Accepted: 07/25/2022] [Indexed: 01/28/2023]
Abstract
Congenital myasthenic syndromes (CMS) are predominantly characterized by muscle weakness and fatigability and can be caused by a variety of mutations in genes required for neuromuscular junction formation and maintenance. Among them, AGRN encodes agrin, an essential synaptic protein secreted by motoneurons. We have identified severe CMS patients with uncharacterized p.R1671Q, p.R1698P and p.L1664P mutations in the LG2 domain of agrin. Overexpression in primary motoneurons cultures in vitro and in chick spinal motoneurons in vivo revealed that the mutations modified agrin trafficking, leading to its accumulation in the soma and/or in the axon. Expression of mutant agrins in cultured cells demonstrated accumulation of agrin in the endoplasmic reticulum associated with induction of unfolded protein response (UPR) and impaired secretion in the culture medium. Interestingly, evaluation of the specific activity of individual agrins on AChR cluster formation indicated that when secreted, mutant agrins retained a normal capacity to trigger the formation of AChR clusters. To confirm agrin accumulation and secretion defect, iPS cells were derived from a patient and differentiated into motoneurons. Patient iPS-derived motoneurons accumulated mutant agrin in the soma and increased XBP1 mRNA splicing, suggesting UPR activation. Moreover, co-cultures of patient iPS-derived motoneurons with myotubes confirmed the deficit in agrin secretion and revealed a reduction in motoneuron survival. Altogether, we report the first mutations in AGRN gene that specifically affect agrin secretion by motoneurons. Interestingly, the three patients carrying these mutations were initially suspected of spinal muscular atrophy (SMA). Therefore, in the presence of patients with a clinical presentation of SMA but without mutation in the SMN1 gene, it can be worth to look for mutations in AGRN.
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Affiliation(s)
- Arnaud Jacquier
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France ,grid.413852.90000 0001 2163 3825Hospices Civils de Lyon, Groupement Est, Bron, France
| | - Valérie Risson
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France
| | - Thomas Simonet
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France ,grid.413852.90000 0001 2163 3825Hospices Civils de Lyon, Groupement Est, Bron, France
| | - Florine Roussange
- grid.503216.30000 0004 0618 2124INSERM/UEPS UMR 861, Paris Saclay Université, I-STEM, 91100 Corbeil-Essonnes, France
| | - Nicolas Lacoste
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France
| | - Shams Ribault
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France ,grid.413852.90000 0001 2163 3825Service de Médecine Physique et de Réadaptation, Hôpital Henry Gabrielle, Hospices Civils de Lyon, 69230 Saint-Genis-Laval, France
| | - Julien Carras
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France ,grid.413852.90000 0001 2163 3825Hospices Civils de Lyon, Groupement Est, Bron, France
| | - Julian Theuriet
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France ,grid.413852.90000 0001 2163 3825Hospices Civils de Lyon, Groupement Est, Bron, France
| | - Emmanuelle Girard
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France
| | - Isabelle Grosjean
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France
| | - Laure Le Goff
- grid.413852.90000 0001 2163 3825Hospices Civils de Lyon, Groupement Est, Bron, France
| | - Stephan Kröger
- Department of Physiological Genomics, Biomedical Center, Planegg, Martinsried, Germany
| | - Julia Meltoranta
- Department of Physiological Genomics, Biomedical Center, Planegg, Martinsried, Germany
| | - Stéphanie Bauché
- grid.462844.80000 0001 2308 1657Inserm U 1127, CNRS UMR 7225, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle Épinière, ICM, Sorbonne Universités, 75013 Paris, France
| | - Damien Sternberg
- grid.462844.80000 0001 2308 1657Inserm U 1127, CNRS UMR 7225, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle Épinière, ICM, Sorbonne Universités, 75013 Paris, France ,grid.411439.a0000 0001 2150 9058APHP, UF Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Emmanuel Fournier
- grid.462844.80000 0001 2308 1657Inserm U 1127, CNRS UMR 7225, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle Épinière, ICM, Sorbonne Universités, 75013 Paris, France ,grid.411439.a0000 0001 2150 9058AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France ,grid.462844.80000 0001 2308 1657Département d’Éthique de l’Université et des enseignements de Physiologie de la Faculté de Médecine Pitié-Salpêtrière, 75013 Paris, France
| | - Anna Kostera-Pruszczyk
- grid.13339.3b0000000113287408Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Emily O’Connor
- grid.28046.380000 0001 2182 2255Division of Neurology, Department of Medicine, Children’s Hospital of Eastern Ontario Research Institute, The Ottawa Hospital and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Bruno Eymard
- grid.462844.80000 0001 2308 1657Inserm U 1127, CNRS UMR 7225, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle Épinière, ICM, Sorbonne Universités, 75013 Paris, France ,grid.411439.a0000 0001 2150 9058AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Hanns Lochmüller
- grid.28046.380000 0001 2182 2255Division of Neurology, Department of Medicine, Children’s Hospital of Eastern Ontario Research Institute, The Ottawa Hospital and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Cécile Martinat
- grid.503216.30000 0004 0618 2124INSERM/UEPS UMR 861, Paris Saclay Université, I-STEM, 91100 Corbeil-Essonnes, France
| | - Laurent Schaeffer
- Pathophysiology and Genetics of Neuron and Muscle, Faculté de Médecine Lyon Est, CNRS UMR 5261, INSERM U1315, Université Lyon1, Lyon, France ,grid.413852.90000 0001 2163 3825Hospices Civils de Lyon, Groupement Est, Bron, France
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Price EA, Krasowska-Zoladek A, Nanda KK, Stachel SJ, Henze DA. Development of a pharmacodynamic biomarker to measure target engagement from inhibition of the NGF-TrkA pathway. J Neurosci Methods 2017; 282:34-42. [PMID: 28279735 DOI: 10.1016/j.jneumeth.2017.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 02/02/2017] [Accepted: 03/02/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND NGF signaling through TrkA triggers pathways involved in a wide range of biological effects. Clinical trials targeting either NGF or TrkA are ongoing to treat various diseases in the areas of oncology, neuroscience, and for pain, but there is no described measure of target engagement of TrkA in these studies. NEW METHOD We have developed custom ELISA assays to measure NGF-induced phosphorylation of TrkA specific for rodent and human receptors. Optimized tissue processing methods allow for detection in both the brain and in skin. In addition, TrkB and TrkC assays have been in established to evaluate selectivity against other neurotrophin receptors. RESULTS In a preclinical NGF-induced pain model, we show that pre-dosing with a TrkA inhibitor prevents phosphorylation of TrkA in the skin at a dose that is efficacious in reversal of thermal hypersensitivity. In addition, we show data in non-human primate and human skin supporting the potential use of this approach to enable translational target engagement. Comparison with existing methods: Existing methods involve animal models expressing TrkA tumors or injection of over-expressing TrkA recombinant cells into animals. Our method can measure target engagement in both normal and disease tissues in preclinical animal models and human skin. CONCLUSIONS We have developed methods to assess target engagement for drug programs aimed at disrupting NGF-induced TrkA signaling. This includes preclinical determination of selectivity against other neurotrophin receptors and estimation of functional peripheral restriction. Preliminary data supports this method can be translated into a clinical pharmacodynamic readout using human skin biopsies.
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Affiliation(s)
- Eric A Price
- Departments of Neuroscience Pain and Department of Medicinal Chemistry, Merck Research Laboratories, Merck & Co., Inc, West Point, PA 19486, USA.
| | - Alicja Krasowska-Zoladek
- Departments of Neuroscience Pain and Department of Medicinal Chemistry, Merck Research Laboratories, Merck & Co., Inc, West Point, PA 19486, USA
| | - Kausik K Nanda
- Departments of Neuroscience Pain and Department of Medicinal Chemistry, Merck Research Laboratories, Merck & Co., Inc, West Point, PA 19486, USA
| | - Shawn J Stachel
- Departments of Neuroscience Pain and Department of Medicinal Chemistry, Merck Research Laboratories, Merck & Co., Inc, West Point, PA 19486, USA
| | - Darrell A Henze
- Departments of Neuroscience Pain and Department of Medicinal Chemistry, Merck Research Laboratories, Merck & Co., Inc, West Point, PA 19486, USA
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Schaub NJ, Johnson CD, Cooper B, Gilbert RJ. Electrospun Fibers for Spinal Cord Injury Research and Regeneration. J Neurotrauma 2016; 33:1405-15. [PMID: 26650778 DOI: 10.1089/neu.2015.4165] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Electrospinning is the process by which a scaffold containing micrometer and nanometer diameter fibers are drawn from a polymer solution or melt using a large voltage gradient between a polymer emitting source and a grounded collector. Ramakrishna and colleagues first investigated electrospun fibers for neural applications in 2004. After this initial study, electrospun fibers are increasingly investigated for neural tissue engineering applications. Electrospun fibers robustly support axonal regeneration within in vivo rodent models of spinal cord injury. These findings suggest the possibility of their eventual use within patients. Indeed, both spinal cord and peripheral nervous system regeneration research over the last several years shows that physical guidance cues induce recovery of limb, respiration, or bladder control in rodent models. Electrospun fibers may be an alternative to the peripheral nerve graft (PNG), because PNG autografts injure the patient and are limited in supply, and allografts risk host rejection. In addition, electrospun fibers can be engineered easily to confront new therapeutic challenges. Fibers can be modified to release therapies locally or can be physically modified to direct neural stem cell differentiation. This review summarizes the major findings and trends in the last decade of research, with a particular focus on spinal cord injury. This review also demonstrates how electrospun fibers can be used to study the central nervous system in vitro.
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Affiliation(s)
- Nicholas J Schaub
- 1 Center for Biotechnology and Interdisciplinary Studies, Rensselear Polytechnic Institute , Troy, New York.,2 Department of Biomedical Engineering, Rensselear Polytechnic Institute , Troy, New York
| | - Christopher D Johnson
- 1 Center for Biotechnology and Interdisciplinary Studies, Rensselear Polytechnic Institute , Troy, New York.,2 Department of Biomedical Engineering, Rensselear Polytechnic Institute , Troy, New York
| | | | - Ryan J Gilbert
- 1 Center for Biotechnology and Interdisciplinary Studies, Rensselear Polytechnic Institute , Troy, New York.,2 Department of Biomedical Engineering, Rensselear Polytechnic Institute , Troy, New York
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5
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Werdehausen R, Braun S, Essmann F, Schulze-Osthoff K, Walczak H, Lipfert P, Stevens MF. Lidocaine induces apoptosis via the mitochondrial pathway independently of death receptor signaling. Anesthesiology 2007; 107:136-43. [PMID: 17585225 DOI: 10.1097/01.anes.0000268389.39436.66] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Local anesthetics, especially lidocaine, can lead to persistent cauda equina syndrome after spinal anesthesia. Recently, lidocaine has been reported to trigger apoptosis, although the underlying mechanisms remain unknown. To elucidate the pathway of lidocaine-induced apoptosis, the authors used genetically modified cells with overexpression or deficiencies of key regulators of apoptosis. METHODS Human Jurkat T-lymphoma cells overexpressing the antiapoptotic protein B-cell lymphoma 2 as well as cells deficient of caspase 9, caspase 8, or Fas-associated protein with death domain were exposed to lidocaine and compared with parental cells. The authors evaluated cell viability, mitochondrial alterations, cytochrome c release, caspase activation, and early apoptosis. Apoptosis was in addition investigated in neuroblastoma cells. RESULTS In Jurkat cells, lidocaine reduced viability, associated with a loss of the mitochondrial membrane potential. At low concentrations (3-6 mm) of lidocaine, caspase 3 was activated and release of cytochrome c was detected, whereas at higher concentrations (10 mm), no caspase activation was found. Apoptosis by lidocaine was strongly reduced by B-cell lymphoma-2 protein overexpression or caspase-9 deficiency, whereas cells lacking the death receptor pathway components caspase 8 and Fas-associated protein with death domain were not protected and displayed similar apoptotic alterations as the parental cells. Lidocaine also induced apoptotic caspase activation in neuroblastoma cells. CONCLUSIONS Apoptosis is triggered by concentrations of lidocaine occurring intrathecally after spinal anesthesia, whereas higher concentrations induce necrosis. The data indicate that death receptors are not involved in lidocaine-induced apoptosis. In contrast, the observation that B-cell lymphoma-2 protein overexpression or the lack of caspase 9 abolished apoptosis clearly implicates the intrinsic mitochondrial death pathway in lidocaine-induced apoptosis.
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Affiliation(s)
- Robert Werdehausen
- Department of Anesthesiology, University of Düsseldorf, Düsseldorf, Germany
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Lachyankar MB, Condon PJ, Daou MC, De AK, Levine JB, Obermeier A, Ross AH. Novel functional interactions between Trk kinase and p75 neurotrophin receptor in neuroblastoma cells. J Neurosci Res 2003; 71:157-72. [PMID: 12503079 DOI: 10.1002/jnr.10480] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To understand the functional interactions between the TrkA and p75 nerve growth factor (NGF) receptors, we stably transfected LAN5 neuroblastoma cells with an expression vector for ET-R, a chimeric receptor with the extracellular domain of the epidermal growth factor receptor (EGFR), and the TrkA transmembrane and intracellular domains. EGF activated the ET-R kinase and induced partial differentiation. NGF, which can bind to endogenous p75, did not induce differentiation but enhanced the EGF-induced response, leading to differentiation of almost all cells. A mutated NGF, 3T-NGF, that binds to TrkA but not to p75 did not synergize with EGF. Enhancement of EGF-induced differentiation required at least nanomolar concentrations of NGF, consistent with the low-affinity p75 binding site. EGF may induce a limited number of neuronal cells because it also enhanced apoptosis. Both NGF and a caspase inhibitor reduced apoptosis and, thereby, enhanced differentiation. NGF seems to enhance survival through the phosphatidylinositol-3 kinase (PI3K) pathway. Consistent with this hypothesis, Akt, a downstream effector of the PI3K pathway, was hyperphosphorylated in the presence of EGF+NGF. These results demonstrate that TrkA kinase initiates differentiation, and p75 enhances differentiation by rescuing differentiating cells from apoptosis via the PI3K pathway. Even though both EGF and NGF are required for differentiation of LAN5/ET-R cells, only NGF is required for survival of the differentiated cells. In the absence of NGF, the cells die by an apoptotic mechanism, involving caspase-3. An anti-p75 antibody blocked the survival effect of NGF. Brain-derived neurotrophic factor also enhanced cell survival, indicating that in differentiated cells, NGF acts through the p75 receptor to prevent apoptosis.
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Affiliation(s)
- Mahesh B Lachyankar
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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Bian X, Opipari AW, Ratanaproeksa AB, Boitano AE, Lucas PC, Castle VP. Constitutively active NFkappa B is required for the survival of S-type neuroblastoma. J Biol Chem 2002; 277:42144-50. [PMID: 12198114 DOI: 10.1074/jbc.m203891200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The NFkappaB transcription factors can both promote cell survival and induce apoptosis depending on cell type and context. Neuroblastoma (NB) cells display two predominant culture phenotypes identified as N- and S-types. Malignant S-type cells express neither high levels of MYCN nor Bcl-2, suggesting that other survival mechanisms are important. We characterized NFkappaB activity in S-type cells and determined its role in their survival. S-type lines (SH-EP1 and SK-N-AS) were treated with pyrrolidine dithiocarbamate (PDTC), a NFkappaB inhibitor, or l-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK), a serine protease inhibitor that blocks IkappaBalpha degradation. Both agents induced cell death, suggesting that constitutive NFkappaB activity is required for survival. The transient expression of a super-repressor IkappaBalpha mutant killed S-type cells. The inhibition of NFkappaB produced an apoptotic response characterized by the collapse of the mitochondrial transmembrane electrochemical gradient, caspase-9 activation, and apoptotic DNA changes. Constitutive NFkappaB DNA binding activity specifically involving p65 and p50 was demonstrated in S- but not N-type cells by electromobility supershift and gene reporter assays. This study demonstrates a role for NFkappaB in the survival of S-type NB tumor cells and suggests that NFkappaB activity and function differ according to NB tumor cell phenotype.
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Affiliation(s)
- Xin Bian
- Department of Pediatrics, University of Michigan, Ann Arbor 48109, USA
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8
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Tombes RM, Mikkelsen RB, Jarvis WD, Grant S. Downregulation of delta CaM kinase II in human tumor cells. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1452:1-11. [PMID: 10525155 DOI: 10.1016/s0167-4889(99)00113-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Over two dozen alternative splice variants of CaMK-II, the type II Ca(2+)/CaM-dependent protein kinase, are encoded from four genes (alpha, beta, gamma and delta) in mammalian cells. Isozymes of alpha and beta CaMK-II are well characterized in brain; however, an understanding of the relative endogenous levels of CaMK-II isozymes in a wide variety of non-neuronal cells has not yet been described. In this study, we have demonstrated that CaMK-II consists primarily of the 54 kDa delta CaMK-II (delta(2) or delta(C)) isozyme in rodent fibroblasts. beta and gamma CaMK-II isozymes are minor and alpha CaMK-II was not expressed. The primary delta CaMK-II in human fibroblasts and the MCF10A mammary epithelial cell line was the 52 kDa delta(4) CaMK-II, an isozyme identical to delta(2) except for a missing 21-amino-acid C-terminal tail. delta CaMK-II levels were diminished in both human and rodent fibroblasts after SV40 transformation and in the mammary adenocarcinoma MCF7 cell line when compared to MCF10A cells. In fact, most tumor cells exhibited CaMK-II specific activities which were two- to tenfold lower than in untransformed fibroblasts. We conducted complementary CaMK-II studies on the NGF-induced differentiation of rat PC-12 cells. Although no new synthesis of CaMK-II occurs, neurite outgrowth in these cells is accompanied by a preferential activation of delta CaMK-II. Endogenous delta CaMK-II has a perinuclear distribution in fibroblasts and extends along neurites in PC-12 cells. These findings point to a role for delta CaMK-II isozymes in cellular differentiation.
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Affiliation(s)
- R M Tombes
- Massey Cancer Center and Department of Biology, Medical College of Virginia Commonwealth University, Richmond, VA 23298, USA.
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da Motta LA, Galli P, Piva F, Maggi R. Effects of epidermal growth factor on the [3H]-thymidine uptake in the SK-N-SH and SH-SY5Y human neuroblastoma cell lines. ARQUIVOS DE NEURO-PSIQUIATRIA 1997; 55:444-51. [PMID: 9629363 DOI: 10.1590/s0004-282x1997000300016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The studies on the factors that regulate the biology of the neuroblastoma cell lines may offer important information on the development of tissues and organs that derive from the neural crest. In the present paper we study the action of epidermal growth factor (EGF) on two human neuroblastoma cell lines: SK-N-SH which is composed at least of two cellular phenotypes (neuroblastic and melanocytic/glial cells), and its pure neuroblastic subclone SH-SY5Y. The results show that EGF (10 ng/ml) significantly stimulates the incorporation of [3H]-thymidine in the SK-N-SH cells only in the presence of fetal bovine serum (FBS) (control = 58,285 +/- 9327 cpm; EGF = 75,523 +/- 4457, p < 0.05). Such effect is not observed in the presence of a chemical defined medium, that is, in the absence of FBS (control = 100,997 +/- 4375; EGF = 95,268 +/- 4683; NS) In the SH-SY5Y cells the EGF does not modify the incorporation of [3H]-thymidine either in the presence of 10% of BFS (control = 113,838 +/- 6978; EGF = 119,434 +/- 9441; NS) or in its absence (control = 46,197 +/- 3335; EGF = 44,472 +/- 3493; NS). The results here reported suggest that: a) EGF may affect the proliferation of cells derived from a primary human neuroblastoma; b) this is evident by the EGF-induced increase of [3H]-thymidine incorporation in SK-N-SH cells; c) it is required the presence of other growth factors, present in the FBS, for the mitogenic action to be accomplished; d) since the pure neuroblastic SH-SY5Y cell line are refractory to the EGF, the effects observed in SK-N-SH cells probably occur on the melanocytic/glial cell subpopulation.
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Affiliation(s)
- L A da Motta
- Neurosurgery Unit, Hospital de Base do Distrito Federal, Brasília DF-Brasil.
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10
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Tombes RM, Krystal GW. Identification of novel human tumor cell-specific CaMK-II variants. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1355:281-92. [PMID: 9060999 DOI: 10.1016/s0167-4889(96)00141-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
CaMK-II (the (type II) multifunctional Ca2+/CaM-dependent protein kinase) has been implicated in diverse neuronal and non-neuronal functions, including cell growth control. CaMKII expression was evaluated in a variety of human tumor cell lines using RT-PCR (reverse transcriptase coupled polymerase chain reaction). PCR primers which flanked the CaMK-II variable domain were used so that all possible variants of the four mammalian CaMK-II genes (alpha, beta, gamma and delta) could be identified. 8 distinct CaMK-II isozymes were identified from human mammary tumor and neuroblastoma cell cDNA, each of which represented a variant of beta, gamma or delta CaMK-II. They included 2 beta isozymes (beta e, beta 'e), 4 gamma isozymes (gamma B, gamma C, gamma G, gamma H) and 2 delta isozymes (delta C, delta E) This is the first report of human beta and delta CaMK-II sequences. A panel of human cell types was then screened for these CaMK-II isozymes. As expected, cerebral cortex predominately expressed alpha, beta and delta A CaMK-II. In contrast, tumor cells, including those of neuronal origin, expressed an entirely different spectrum of CaMK-II isozymes than adult neuronal tissue. Tumor cells of diverse tissue origin uniformly lacked alpha CaMK-II and expressed 1-2 beta isozymes, at least 3 gamma isozymes and 1-2 delta isozymes. When compared to undifferentiated fibroblasts, beta e, beta'e, gamma G and gamma H were preferentially expressed in tumor cells. CaMK-II immunoblots also indicated that neuroblastoma and mammary tumor cells express isozymes of CaMK-II not present in their non-transformed cell or tissue counterpart. The identification of these new, potential tumor-specific CaMK-II variants supports previous indications that CaMK-II plays a role in growth control. In addition, these results provide insight into both splice variant switching and variable domain structural similarities among all CaMK-II isozymes.
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Affiliation(s)
- R M Tombes
- Massey Cancer Center, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0037, USA
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Janet T, Lüdecke G, Otten U, Unsicker K. Heterogeneity of human neuroblastoma cell lines in their proliferative responses to basic FGF, NGF, and EGF: correlation with expression of growth factors and growth factor receptors. J Neurosci Res 1995; 40:707-15. [PMID: 7629887 DOI: 10.1002/jnr.490400602] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Growth factors can induce both proliferation or differentiation of neuroblastoma (NB) cells through interaction with specific receptors. Using two automated colorimetric assays for determinations of cell numbers, the present study demonstrates that a) different NB and neuroepithelioma cell lines show distinct responses, both qualitatively and quantitatively, to basic FGF (bFGF), NGF, and EGF; b) even closely related NB cell lines (e.g., SK-N-SH, SH-SY5Y, and SHEP) do not respond uniformly to these factors; c) responses of the two neuroepithelioma cell lines employed (SK-N-MC and CHP-100) differ, but match those of certain NB cell lines; and d) two growth factors, bFGF and EGF, may both stimulate or inhibit proliferation, depending on the cell line studied. Specifically, IMR-32, SK-N-SH, and SH-SY5Y showed a mitogenic response to each growth factor. Maximal proliferative responses ranged from 204-355% as compared to controls (100%). GICAN was stimulated by NGF (199%), and SK-N-MC and NMB by EGF (282 and 140%, respectively), but other factors were ineffective. CHP-100 and GIMEN were inhibited by bFGF. NGF and EGF were not effective on CHP-100 cells, while EGF caused an arrest of mitogenic activity in GIMEN cells, and NGF stimulated their proliferation. Cell lines SHEP and LAN1 did not respond to any factor. To begin to analyze putative relationships of growth factor responsiveness and growth factor/growth factor receptor expressions, IMR-32, GIMEN, and LAN1 cell lines were studied for the presence of bFGF, NGF, FGF receptors (R)-1 (flg) and FGFR-4, trk, and low-affinity NGF receptor (p75) mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T Janet
- Department of Anatomy and Cell Biology, University of Heidelberg, Germany
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Nakagawara A, Arima-Nakagawara M, Scavarda NJ, Azar CG, Cantor AB, Brodeur GM. Association between high levels of expression of the TRK gene and favorable outcome in human neuroblastoma. N Engl J Med 1993; 328:847-54. [PMID: 8441429 DOI: 10.1056/nejm199303253281205] [Citation(s) in RCA: 521] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND METHODS The nerve growth factor receptor is expressed in some neuroblastomas, in which its primary component is encoded by the TRK protooncogene. To determine the relation of the expression of TRK messenger RNA in neuroblastomas to other clinical and laboratory variables, we studied frozen tumor samples from 77 patients. In addition, we tested two primary neuroblastomas that expressed TRK for responsiveness to nerve growth factor. RESULTS TRK expression strongly correlated with favorable tumor stage (I, II, and IVS vs. III and IV), younger age (< 1 year vs. > or = 1 year), normal N-myc copy number, and low level of N-myc expression. N-myc amplification (indicated by a high copy number) correlated with advanced tumor stage, older age, an adrenal site of the primary tumor, low level of expression of TRK, and high level of expression of N-myc. Analysis of five-year cumulative-survival rates demonstrated an association of a very favorable outcome with a high level of TRK expression (86 percent vs. 14 percent) and with normal N-myc copy number (84 percent vs. 0 percent). Univariate analysis showed that these two variables were the most powerful predictors of outcome (chi-square = 51.30, P < 0.001; and chi-square = 93.61, P < 0.001, respectively). TRK expression still had significant prognostic value when the analysis was restricted to tumors without N-myc amplification. In primary cultures of neuroblastoma cells expressing TRK, exposure to nerve growth factor induced early gene expression and neurite outgrowth, but deprivation of nerve growth factor led to neuronal cell death. CONCLUSIONS A high level of expression of the TRK proto-oncogene in a neuroblastoma is strongly predictive of a favorable outcome. A tumor with a functional nerve growth factor receptor may be dependent on the neurotrophin nerve growth factor for survival and may regress in its absence, allowing a new approach to the treatment of certain patients with neuroblastoma.
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Affiliation(s)
- A Nakagawara
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110
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Hutton LA, deVellis J, Perez-Polo JR. Expression of p75NGFR TrkA, and TrkB mRNA in rat C6 glioma and type I astrocyte cultures. J Neurosci Res 1992; 32:375-83. [PMID: 1279189 DOI: 10.1002/jnr.490320309] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) we have investigated the expression of the neurotrophin receptors p75NGFR, trkA, and trkB mRNAs in cultures of rat pup type I astrocytes and in the C6 rat glioma cell line. All three neurotrophin receptor mRNAs are expressed in both C6 cells and in type I astrocytic cultures. p75NGFR mRNA levels are increased by either cycloheximide or nerve growth factor (NGF) treatment of C6 cells as measured using RT-PCR. Type I astrocyte cultures also expressed p75NGFR mRNA and NGF treatment increased p75NGFR mRNA levels in these cultures. TrkB mRNA levels were increased by cycloheximide treatment of type I astrocyte cultures but not by NGF treatment. Using RT-PCR, trkA mRNA was detected in astrocytic cultures as well as in the rat C6 and PC-12 cell lines. We conclude that cultures of type I astrocytes express active NGF receptors and that glia can elicit a response to NGF as seen by an increase in p75NGFR mRNA levels following exposure to NGF.
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Affiliation(s)
- L A Hutton
- Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston 77555
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Venkatakrishnan G, McKinnon CA, Pilapil CG, Wolf DE, Ross AH. Nerve growth factor receptors are preaggregated and immobile on responsive cells. Biochemistry 1991; 30:2748-53. [PMID: 1848776 DOI: 10.1021/bi00225a002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
It has been hypothesized that signal transduction occurs by ligand-induced receptor clustering and immobilization. For many peptide receptors, cross-linking by anti-receptor antibodies is sufficient for receptor activation. This is not, however, the case for nerve growth factor receptor (NGFR). Using fluorescence microscopy and fluorescence recovery after photobleaching (FRAP), we have analyzed the distribution and diffusibility of NGFR on a series of cell lines. We have found the following: (1) Cells expressing high-affinity responsive NGFR's display clustered NGFR's even in the absence of ligand. In contrast, NGFR's in nonresponsive cell lines are diffusely distributed. (2) Receptors on responsive cell lines are largely nondiffusing while most receptors on nonresponsive cell lines are relatively free to diffuse. (3) NGF does not greatly alter the distribution or diffusion properties of the NGFR on either nonresponsive or responsive cell lines. Thus, NGFR is preclustered and immobile on responsive cells, which suggests that immobilization of NGFR prior to ligand binding is required for signal transduction.
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Affiliation(s)
- G Venkatakrishnan
- Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
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Rakowicz-Szulczynska EM, Reddy U, Vorbrodt A, Herlyn D, Koprowski H. Chromatin and cell surface receptors mediate melanoma cell growth response to nerve growth factor. Mol Carcinog 1991; 4:388-96. [PMID: 1654924 DOI: 10.1002/mc.2940040511] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Growth response to nerve growth factor (NGF) was tested in the primary melanoma cell line WM 164, which expressed a low level of NGF cell-surface receptor, and in WM 164 cells transfected with cDNA for the cell-surface receptor (TrWM 164 cells), which expressed a higher level of the cell-surface receptor. Neither cell line expressed the chromatin receptor for NGF or internalized NGF. Both cell lines were stimulated to growth by NGF. After 10 d of exposure to NGF, a 230,000 Mr chromatin protein (receptor) was induced in both cell lines; as a result, NGF bound to the chromatin, and ribosomal RNA synthesis and cell proliferation were inhibited. We suggest that the cell-surface and chromatin receptors each mediate a different function of NGF.
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