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Ruiz-García C, Lassaletta L, López-Larrubia P, Varela-Nieto I, Murillo-Cuesta S. Tumors of the nervous system and hearing loss: Beyond vestibular schwannomas. Hear Res 2024; 447:109012. [PMID: 38703433 DOI: 10.1016/j.heares.2024.109012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/08/2024] [Accepted: 04/18/2024] [Indexed: 05/06/2024]
Abstract
Hearing loss is a common side effect of many tumor treatments. However, hearing loss can also occur as a direct result of certain tumors of the nervous system, the most common of which are the vestibular schwannomas (VS). These tumors arise from Schwann cells of the vestibulocochlear nerve and their main cause is the loss of function of NF2, with 95 % of cases being sporadic and 5 % being part of the rare neurofibromatosis type 2 (NF2)-related Schwannomatosis. Genetic variations in NF2 do not fully explain the clinical heterogeneity of VS, and interactions between Schwann cells and their microenvironment appear to be critical for tumor development. Preclinical in vitro and in vivo models of VS are needed to develop prognostic biomarkers and targeted therapies. In addition to VS, other tumors can affect hearing. Meningiomas and other masses in the cerebellopontine angle can compress the vestibulocochlear nerve due to their anatomic proximity. Gliomas can disrupt several neurological functions, including hearing; in fact, glioblastoma multiforme, the most aggressive subtype, may exhibit early symptoms of auditory alterations. Besides, treatments for high-grade tumors, including chemotherapy or radiotherapy, as well as incomplete resections, can induce long-term auditory dysfunction. Because hearing loss can have an irreversible and dramatic impact on quality of life, it should be considered in the clinical management plan of patients with tumors, and monitored throughout the course of the disease.
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Affiliation(s)
- Carmen Ruiz-García
- Department of Otorhinolaryngology, La Paz University Hospital. Paseo La Castellana 261, Madrid 28046, Spain; Research in Otoneurosurgery. Hospital La Paz Institute for Health Research - IdiPAZ (La Paz University Hospital - Universidad Autónoma de Madrid), Paseo La Castellana 261, Madrid 28046, Spain; Neuropathology of Hearing and Myelinopathies, Instituto de Investigaciones Biomédicas Sols-Morreale, CSIC-UAM. Arturo Duperier 4, Madrid 28029, Spain; PhD Program in Medicine and Surgery, Autonomous University of Madrid, Madrid, Spain
| | - Luis Lassaletta
- Department of Otorhinolaryngology, La Paz University Hospital. Paseo La Castellana 261, Madrid 28046, Spain; Research in Otoneurosurgery. Hospital La Paz Institute for Health Research - IdiPAZ (La Paz University Hospital - Universidad Autónoma de Madrid), Paseo La Castellana 261, Madrid 28046, Spain; Biomedical Research Networking Centre On Rare Diseases (CIBERER), Institute of Health Carlos III, Monforte de Lemos 9-11, Madrid 28029, Spain
| | - Pilar López-Larrubia
- Biomedical Magnetic Resonance, Instituto de Investigaciones Biomédicas Sols-Morreale, CSIC-UAM. Arturo Duperier 4, Madrid 28029, Spain
| | - Isabel Varela-Nieto
- Research in Otoneurosurgery. Hospital La Paz Institute for Health Research - IdiPAZ (La Paz University Hospital - Universidad Autónoma de Madrid), Paseo La Castellana 261, Madrid 28046, Spain; Neuropathology of Hearing and Myelinopathies, Instituto de Investigaciones Biomédicas Sols-Morreale, CSIC-UAM. Arturo Duperier 4, Madrid 28029, Spain; Biomedical Research Networking Centre On Rare Diseases (CIBERER), Institute of Health Carlos III, Monforte de Lemos 9-11, Madrid 28029, Spain.
| | - Silvia Murillo-Cuesta
- Research in Otoneurosurgery. Hospital La Paz Institute for Health Research - IdiPAZ (La Paz University Hospital - Universidad Autónoma de Madrid), Paseo La Castellana 261, Madrid 28046, Spain; Neuropathology of Hearing and Myelinopathies, Instituto de Investigaciones Biomédicas Sols-Morreale, CSIC-UAM. Arturo Duperier 4, Madrid 28029, Spain; Biomedical Research Networking Centre On Rare Diseases (CIBERER), Institute of Health Carlos III, Monforte de Lemos 9-11, Madrid 28029, Spain.
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Wetzker R. Hormesis Meetings at the Royal Palace. Dose Response 2022; 19:15593258211056835. [PMID: 34987333 PMCID: PMC8669123 DOI: 10.1177/15593258211056835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022]
Abstract
This commentary describes the origin and the main results of experimental work on adaptive stress responses at the university town Jena in Germany. These cooperative research activities exemplify the heuristic power of the hormesis phenomenon.
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Affiliation(s)
- Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
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3
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Ishan M, Chen G, Yu W, Wang Z, Giovannini M, Cao X, Liu HX. Deletion of Nf2 in neural crest-derived tongue mesenchyme alters tongue shape and size, Hippo signalling and cell proliferation in a region- and stage-specific manner. Cell Prolif 2021; 54:e13144. [PMID: 34697858 PMCID: PMC8666282 DOI: 10.1111/cpr.13144] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/02/2022] Open
Abstract
Objectives The mammalian tongue develops from the branchial arches (1–4) and comprises highly organized tissues compartmentalized by mesenchyme/connective tissue that is largely derived from neural crest (NC). This study aimed to understand the roles of tumour suppressor Neurofibromin 2 (Nf2) in NC‐derived tongue mesenchyme in regulating Hippo signalling and cell proliferation for the proper development of tongue shape and size. Materials and methods Conditional knockout (cKO) of Nf2 in NC cell lineage was generated using Wnt1‐Cre (Wnt1‐Cre/Nf2cKO). Nf2 expression, Hippo signalling activities, cell proliferation and tongue shape and size were thoroughly analysed in different tongue regions and tissue types of Wnt1‐Cre/Nf2cKO and Cre‐/Nf2fx/fx littermates at various stages (E10.5–E18.5). Results In contrast to many other organs in which the Nf2/Hippo pathway activity restrains growth and cell proliferation and as a result, loss of Nf2 decreases Hippo pathway activity and promotes an enlarged organ development, here we report our observations of distinct, tongue region‐ and stage‐specific alterations of Hippo signalling activity and cell proliferation in Nf2cKO in NC‐derived tongue mesenchyme. Compared to Cre−/Nf2fx/fx littermates, Wnt1‐Cre/Nf2cKO depicted a non‐proportionally enlarged tongue (macroglossia) at E12.5–E13.5 and microglossia at later stages (E15.5–E18.5). Specifically, at E12.5 Nf2cKO mutants had a decreased level of Hippo signalling transcription factor Yes‐associated protein (Yap), Yap target genes and cell proliferation anteriorly, while having an increased Yap, Yap target genes and cell proliferation posteriorly, which lead to a tip‐pointed and posteriorly widened tongue. At E15.5, loss of Nf2 in the NC lineage resulted in distinct changes in cell proliferation in different regions, that is, high in epithelium and mesenchyme subjacent to the epithelium, and lower in deeper layers of the mesenchyme. At E18.5, cell proliferation was reduced throughout the Nf2cKO tongue.
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Affiliation(s)
- Mohamed Ishan
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Guiqian Chen
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Wenxin Yu
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Zhonghou Wang
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Marco Giovannini
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Xinwei Cao
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
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4
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Godel T, Bäumer P, Farschtschi S, Püschel K, Hofstadler B, Heiland S, Gelderblom M, Bendszus M, Hagel C, Mautner VF. Long-term Follow-up and Histological Correlation of Peripheral Nervous System Alterations in Neurofibromatosis Type 2. Clin Neuroradiol 2021; 32:277-285. [PMID: 34652463 PMCID: PMC8894150 DOI: 10.1007/s00062-021-01102-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/07/2021] [Indexed: 12/22/2022]
Abstract
Purpose To examine long-term alterations of the dorsal root ganglia (DRG) and the peripheral nerve in patients with neurofibromatosis type 2 (NF2) by in vivo high-resolution magnetic resonance neurography (MRN) and their correlation to histology. Methods In this prospective study the lumbosacral DRG, the right sciatic, tibial, and peroneal nerves were examined in 6 patients diagnosed with NF2 and associated polyneuropathy (PNP) by a standardized MRN protocol at 3 T. Volumes of DRG L3–S2 as well as peripheral nerve lesions were assessed and compared to follow-up examinations after 14–100 months. In one patient, imaging findings were further correlated to histology. Results Follow-up MRN examination showed a non-significant increase of volume for the DRG L3: +0.41% (p = 0.10), L4: +22.41% (p = 0.23), L5: +3.38% (p = 0.09), S1: +10.63% (p = 0.05) and S2: +1.17% (p = 0.57). Likewise, peripheral nerve lesions were not significantly increased regarding size (2.18 mm2 vs. 2.15 mm2, p = 0.89) and number (9.00 vs. 9.33, p = 0.36). Histological analyses identified schwannomas as the major correlate of both DRG hyperplasia and peripheral nerve lesions. For peripheral nerve microlesions additionally clusters of onion-bulb formations were identified. Conclusion Peripheral nervous system alterations seem to be constant or show only a minor increase in adult NF2. Thus, symptoms of PNP may not primarily attributed to the initial schwannoma growth but to secondary long-term processes, with symptoms only occurring if a certain threshold is exceeded. Histology identified grouped areas of Schwann cell proliferations as the correlate of DRG hyperplasia, while for peripheral nerve lesions different patterns could be found.
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Affiliation(s)
- Tim Godel
- Department of Neuroradiology, Neurological University Clinic, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
| | - Philipp Bäumer
- Department of Neuroradiology, Neurological University Clinic, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Center for Radiology dia.log, Vinzenz-von-Paul Str. 8, 84503, Altötting, Germany
| | - Said Farschtschi
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Klaus Püschel
- Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Barbara Hofstadler
- Department of Neuroradiology, Neurological University Clinic, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, Neurological University Clinic, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Mathias Gelderblom
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Neurological University Clinic, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Christian Hagel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Victor-Felix Mautner
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
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Previtali SC. Peripheral Nerve Development and the Pathogenesis of Peripheral Neuropathy: the Sorting Point. Neurotherapeutics 2021; 18:2156-2168. [PMID: 34244926 PMCID: PMC8804061 DOI: 10.1007/s13311-021-01080-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2021] [Indexed: 12/12/2022] Open
Abstract
Nerve development requires a coordinated sequence of events and steps to be accomplished for the generation of functional peripheral nerves to convey sensory and motor signals. Any abnormality during development may result in pathological structure and function of the nerve, which evolves in peripheral neuropathy. In this review, we will briefly describe different steps of nerve development while we will mostly focus on the molecular mechanisms involved in radial sorting of axons, one of these nerve developmental steps. We will summarize current knowledge of molecular pathways so far reported in radial sorting and their possible interactions. Finally, we will describe how disruption of these pathways may result in human neuropathies.
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Affiliation(s)
- Stefano C Previtali
- Neuromuscular Repair Unit, InSpe (Institute of Experimental Neurology) and Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.
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PLPP/CIN-mediated NF2-serine 10 dephosphorylation regulates F-actin stability and Mdm2 degradation in an activity-dependent manner. Cell Death Dis 2021; 12:37. [PMID: 33414453 PMCID: PMC7791067 DOI: 10.1038/s41419-020-03325-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 12/17/2022]
Abstract
Neurofibromin 2 (NF2, also known as merlin) is a tumor suppressor protein encoded by the neurofibromatosis type 2 gene NF2. NF2 is also an actin-binding protein that functions in an intrinsic signaling network critical for actin dynamics. Although protein kinase A (PKA)-mediated NF2-serin (S) 10 phosphorylation stabilizes filamentous actin (F-actin), the underlying mechanisms of NF2-S10 dephosphorylation and the role of NF2 in seizures have been elusive. Here, we demonstrate that pyridoxal-5′-phosphate phosphatase/chronophin (PLPP/CIN) dephosphorylated NF2-S10 site as well as cofilin-S3 site. In addition, NF2-S10 dephosphorylation reversely regulated murine double minute-2 (Mdm2) and postsynaptic density 95 (PSD95) degradations in an activity-dependent manner, which increased seizure intensity and its progression in response to kainic acid (KA). In addition, NF2 knockdown facilitated seizure intensity and its progress through F-actin instability independent of cofilin-mediated actin dynamics. Therefore, we suggest that PLPP/CIN may be a potential therapeutic target for epileptogenesis and NF2-associated diseases.
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Wei Y, Yee PP, Liu Z, Zhang L, Guo H, Zheng H, Anderson B, Gulley M, Li W. NEDD4L-mediated Merlin ubiquitination facilitates Hippo pathway activation. EMBO Rep 2020; 21:e50642. [PMID: 33058421 DOI: 10.15252/embr.202050642] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 02/01/2023] Open
Abstract
The tumor suppressor Merlin/NF2, a key activator of the Hippo pathway in growth control, is regulated by phosphorylation. However, it is uncertain whether additional post-translational modifications regulate Merlin. Here, we show that ubiquitination is required to activate Merlin in the Hippo pathway. Ubiquitinated Merlin is mostly conjugated by one or two ubiquitin molecules. Such modification is promoted by serine 518 dephosphorylation in response to Ca2+ signaling or cell detachment. Merlin ubiquitination is mediated by the E3 ubiquitin ligase, NEDD4L, which requires a scaffold protein, AMOTL1, to approach Merlin. Several NF2-patient-derived Merlin mutations disrupt its binding to AMOTL1 and its regulation by the AMOTL1-NEDD4L apparatus. Lysine (K) 396 is the major ubiquitin conjugation residue. Disruption of Merlin ubiquitination by the K396R mutation or NEDD4L depletion diminishes its binding to Lats1 and inhibits Lats1 activation. These effects are also accompanied by loss of Merlin's anti-mitogenic and tumor suppressive properties. Thus, we propose that dephosphorylation and ubiquitination compose an intramolecular relay to activate Merlin functions in activating the Hippo pathway during growth control.
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Affiliation(s)
- Yiju Wei
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
| | - Patricia P Yee
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
| | - Zhijun Liu
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
| | - Lei Zhang
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA.,Hepatic Surgery Center, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Guo
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
| | - Haiyan Zheng
- Biological Mass Spectrometry Facility, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Benjamin Anderson
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
| | - Melissa Gulley
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
| | - Wei Li
- Division of Hematology and Oncology, Department of Pediatrics, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA.,Department of Biochemistry and Molecular Biology, Penn State Health Hershey Medical Center, Penn State College of Medicine, Hershey, PA, USA
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Farschtschi S, Mautner VF, McLean ACL, Schulz A, Friedrich RE, Rosahl SK. The Neurofibromatoses. DEUTSCHES ARZTEBLATT INTERNATIONAL 2020; 117:354-360. [PMID: 32657748 DOI: 10.3238/arztebl.2020.0354] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 04/18/2019] [Accepted: 03/20/2020] [Indexed: 01/10/2023]
Abstract
BACKGROUND Neurofibromatosis of types 1 and 2 (NF1, NF2) and schwannomatosis are the diseases that make up the neurofibromatosis spectrum. With respective incidences of 1 in 3000, 1 in 33 000, and 1 in 60 000 births, they form part of the group of rare tumor-suppressor syndromes. They give rise to a greater tumor burden for the nervous system than any other type of neoplastic disease. New approaches to symptomatic treatment are emerging. METHODS This review is based on articles retrieved by a selective literature search on the pathogenesis, diagnosis, and treatment of the neurofibromatoses. RESULTS NF1 and NF2 are monogenic diseases, while the genetics of schwannomatosis is complex. The three entities are clinically and pathophysiologically distinct. An important aspect of their tumor biology is the alternation of growth phases and growth pauses. Correlations between genotypes and phenotypes are variable, while new mutations and genetic mosaics are common. Ninety-nine percent of patients with NF1 have six or more café-au-lait spots by the age of 12 months; 90-95% of patients with NF2 develop bilateral vestibular schwannomas. In schwannomatosis, pain is the most prominent symptom; two-thirds of those affected develop spinal schwannomas. The severity and prognosis of these disorders are not closely correlated with the radiological findings; rather, neurologic deficits, malignant transformation, and psychosocial stress are of greater clinical importance. Advances in knowledge of pathophysiology have led to the development of targeted treatment approaches. Examples include the off-label treatment of vestibular schwannomas with bevacizumab and of plexiform neurofibromas with MEK inhibitors. CONCLUSION Patients with neurofibromatoses need individualized care. They should be treated in centers of expertise where interdisciplinary consultation is available and new types of pharmacotherapy can be provided.
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Affiliation(s)
- Said Farschtschi
- International Center for Neurofibromatoses (ICNF), Department of Neurology, University MedicalCenter Hamburg-Eppendorf
| | - Victor-Felix Mautner
- International Center for Neurofibromatoses (ICNF), Department of Neurology, University MedicalCenter Hamburg-Eppendorf
| | | | | | - Reinhard E Friedrich
- Department of Oromaxillofacial Surgery, University Medical Center Hamburg-Eppendorf
| | - Steffen K Rosahl
- Neurofibromatosis Center, Department of Neurosurgery, Helios Hospital Erfurt
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Association of intraneural perineurioma with neurofibromatosis type 2. Acta Neurochir (Wien) 2020; 162:1891-1897. [PMID: 32529330 DOI: 10.1007/s00701-020-04439-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/27/2020] [Indexed: 12/31/2022]
Abstract
BACKGROUND Neurofibromatosis type 2 (NF2) is a genetic disorder characterized by mutations of the NF2 tumor suppressor gene that predisposes patients to develop multiple tumors in the peripheral and central nervous system. The most common neoplasms associated with the disease are schwannomas and meningiomas. Both have been shown to contain abnormalities in chromosome 22 and the NF2 gene, suggesting a genetic component to their pathogenesis. Perineuriomas are rare benign tumors arising from the perineural cells. They are commonly classified as intraneural and soft tissue perineuriomas. Several studies have reported mutations in genes on chromosome 22 in both types of perineuriomas, and there are reports of soft tissue perineuriomas associated with NF2 gene mutations. Despite this, perineuriomas are not considered as part of the NF2 constellation of tumors. METHOD The electronic medical records were searched for patients with a radiologic or pathologic diagnosis of intraneural perineurioma. Patients with clinical signs and genetic testing consistent with a diagnosis of NF2 were further evaluated. RESULTS Of 112 patients meeting inclusion criteria, there were two cases of intraneural perineurioma in patients with NF2 treated at our institution (1.8%). We include a third patient treated at another facility for whom we performed a virtual consultation. CONCLUSIONS The rarity of both NF2 and perineuriomas could explain the rarity of perineuriomas in the setting of NF2. Furthermore, there is divergent intraneural and soft tissue perineurioma somatic mutation pathogenesis, and there may be cytogenetic overlap between perineuriomas and multiple tumor syndromes. Our observed occurrence of intraneural perineurioma in the setting of NF2 in several patients provides further evidence of a potential link between the NF2 gene and the development of intraneural perineurioma.
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10
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Molecular Analysis of a Patient With Neurofibromatosis 2 (NF2) and Peritoneal Malignant Mesothelioma. Am J Surg Pathol 2020; 44:288-292. [PMID: 31567203 DOI: 10.1097/pas.0000000000001359] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Neurofibromatosis type 2 (NF2), an inherited disorder associated with multiple inherited schwannomas, meningiomas and ependymomas is caused by an autosomal dominant, likely loss of function germline mutation of the NF2 gene. Interestingly, biallelic NF2 gene inactivation is one of the most common mutations associated with the development of malignant mesothelioma (MM), a highly fatal malignancy that arises in the pleura and less frequently in the pericardium, peritoneum, and tunica vaginalis. It has been proposed that NF2 patients could potentially be at increased risk of developing MM. However, patients with inherited NF2 rarely develop MM. To date, only 2 cases describing patients diagnosed with both have been reported in the literature. Here, we describe the third case and for the first time, also provide molecular evidence that a "second hit" involving a somatic mutation is likely required to trigger the development of MM in this rare cohort. In our patient diagnosed with NF2 at age 25 who developed an aggressive peritoneal MM 15 years later, we identified a germline NF2 mutation and somatic mutations including BAP1. Of clinical relevance, our case supports a germline NF2 mutation may not necessarily be more susceptible to develop mesothelioma without a "second hit" mutation.
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Trujillo-Gonzalez I, Friday WB, Munson CA, Bachleda A, Weiss ER, Alam NM, Sha W, Zeisel SH, Surzenko N. Low availability of choline in utero disrupts development and function of the retina. FASEB J 2019; 33:9194-9209. [PMID: 31091977 PMCID: PMC6662989 DOI: 10.1096/fj.201900444r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/15/2019] [Indexed: 12/14/2022]
Abstract
Adequate supply of choline, an essential nutrient, is necessary to support proper brain development. Whether prenatal choline availability plays a role in development of the visual system is currently unknown. In this study, we addressed the role of in utero choline supply for the development and later function of the retina in a mouse model. We lowered choline availability in the maternal diet during pregnancy and assessed proliferative and differentiation properties of retinal progenitor cells (RPCs) in the developing prenatal retina, as well as visual function in adult offspring. We report that low choline availability during retinogenesis leads to persistent retinal cytoarchitectural defects, ranging from focal lesions with displacement of retinal neurons into subretinal space to severe hypocellularity and ultrastructural defects in photoreceptor organization. We further show that low choline availability impairs timely differentiation of retinal neuronal cells, such that the densities of early-born retinal ganglion cells, amacrine and horizontal cells, as well as cone photoreceptor precursors, are reduced in low choline embryonic d 17.5 retinas. Maintenance of higher proportions of RPCs that fail to exit the cell cycle underlies aberrant neuronal differentiation in low choline embryos. Increased RPC cell cycle length, and associated reduction in neurofibromin 2/Merlin protein, an upstream regulator of the Hippo signaling pathway, at least in part, explain aberrant neurogenesis in low choline retinas. Furthermore, we find that animals exposed to low choline diet in utero exhibit a significant degree of intraindividual variation in vision, characterized by marked functional discrepancy between the 2 eyes in individual animals. Together, our findings demonstrate, for the first time, that choline availability plays an essential role in the regulation of temporal progression of retinogenesis and provide evidence for the importance of adequate supply of choline for proper development of the visual system.-Trujillo-Gonzalez, I., Friday, W. B., Munson, C. A., Bachleda, A., Weiss, E. R., Alam, N. M., Sha, W., Zeisel, S. H., Surzenko, N. Low availability of choline in utero disrupts development and function of the retina.
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Affiliation(s)
- Isis Trujillo-Gonzalez
- Nutrition Research Institute, University of North Carolina–Chapel Hill, Kannapolis, North Carolina, USA
| | - Walter B. Friday
- Nutrition Research Institute, University of North Carolina–Chapel Hill, Kannapolis, North Carolina, USA
| | - Carolyn A. Munson
- Nutrition Research Institute, University of North Carolina–Chapel Hill, Kannapolis, North Carolina, USA
| | - Amelia Bachleda
- Department of Cell Biology and Physiology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ellen R. Weiss
- Department of Cell Biology and Physiology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nazia M. Alam
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
- Center for Visual Restoration, Burke Neurological Institute, White Plains, New York, USA
| | - Wei Sha
- Bioinformatics Services Division, University of North Carolina–Charlotte, Kannapolis, North Carolina, USA
| | - Steven H. Zeisel
- Nutrition Research Institute, University of North Carolina–Chapel Hill, Kannapolis, North Carolina, USA
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Natalia Surzenko
- Nutrition Research Institute, University of North Carolina–Chapel Hill, Kannapolis, North Carolina, USA
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
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12
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Mandati V, Del Maestro L, Dingli F, Lombard B, Loew D, Molinie N, Romero S, Bouvard D, Louvard D, Gautreau AM, Pasmant E, Lallemand D. Phosphorylation of Merlin by Aurora A kinase appears necessary for mitotic progression. J Biol Chem 2019; 294:12992-13005. [PMID: 31296571 DOI: 10.1074/jbc.ra118.006937] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 06/25/2019] [Indexed: 01/01/2023] Open
Abstract
Although Merlin's function as a tumor suppressor and regulator of mitogenic signaling networks such as the Ras/rac, Akt, and Hippo pathways is well-documented, in mammals as well as in insects, its role during cell cycle progression remains unclear. In this study, using a combination of approaches, including FACS analysis, time-lapse imaging, immunofluorescence microscopy, and co-immunoprecipitation, we show that Ser-518 of Merlin is a substrate of the Aurora protein kinase A during mitosis and that its phosphorylation facilitates the phosphorylation of a newly discovered site, Thr-581. We found that the expression in HeLa cells of a Merlin variant that is phosphorylation-defective on both sites leads to a defect in centrosomes and mitotic spindles positioning during metaphase and delays the transition from metaphase to anaphase. We also show that the dual mitotic phosphorylation not only reduces Merlin binding to microtubules but also timely modulates ezrin interaction with the cytoskeleton. Finally, we identify several point mutants of Merlin associated with neurofibromatosis type 2 that display an aberrant phosphorylation profile along with defective α-tubulin-binding properties. Altogether, our findings of an Aurora A-mediated interaction of Merlin with α-tubulin and ezrin suggest a potential role for Merlin in cell cycle progression.
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Affiliation(s)
- Vinay Mandati
- CNRS, UMR144, Institute Curie, PSL Research University, F-75005 Paris, France
| | | | - Florent Dingli
- Laboratoire de Spectrométrie de Masse Protéomique, Institute Curie, PSL Research University, Paris, France
| | - Bérangère Lombard
- Laboratoire de Spectrométrie de Masse Protéomique, Institute Curie, PSL Research University, Paris, France
| | - Damarys Loew
- Laboratoire de Spectrométrie de Masse Protéomique, Institute Curie, PSL Research University, Paris, France
| | - Nicolas Molinie
- BIOC, CNRS UMR7654, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - Stephane Romero
- BIOC, CNRS UMR7654, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - Daniel Bouvard
- INSERM, Institut Albert Bonniot U823, F-38042 Grenoble, France
| | - Daniel Louvard
- CNRS, UMR144, Institute Curie, PSL Research University, F-75005 Paris, France
| | - Alexis M Gautreau
- BIOC, CNRS UMR7654, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - Eric Pasmant
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Dominique Lallemand
- CNRS, UMR144, Institute Curie, PSL Research University, F-75005 Paris, France.
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13
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Toledo A, Lang F, Doengi M, Morrison H, Stein V, Baader SL. Merlin modulates process outgrowth and synaptogenesis in the cerebellum. Brain Struct Funct 2019; 224:2121-2142. [PMID: 31165301 DOI: 10.1007/s00429-019-01897-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 05/29/2019] [Indexed: 12/14/2022]
Abstract
Neurofibromatosis type 2 (NF2) patients are prone to develop glial-derived tumors in the peripheral and central nervous system (CNS). The Nf2 gene product -Merlin is not only expressed in glia, but also in neurons of the CNS, where its function still remains elusive. Here, we show that cerebellar Purkinje cells (PCs) of isoform-specific Merlin-deficient mice were innervated by smaller vGluT2-positive clusters at presynaptic terminals than those of wild-type mice. This was paralleled by a reduction in frequency and amplitude of miniature excitatory postsynaptic currents (mEPSC). On the contrary, in conditional transgenic mice in which Merlin expression was specifically ablated in PCs (L7Cre;Nf2fl/fl), we found enlarged vGluT2-positive clusters in their presynaptic buttons together with increased amplitudes of miniature postsynaptic currents. The presynaptic terminals of these PCs innervating neurons of the deep cerebellar nuclei were also enlarged. When exploring mice with Merlin-deficient granule cells (GCs) (Math1Cre;Nf2fl/fl), we found cerebellar extracts to contain higher amounts of vGluT1 present in parallel fiber terminals. In parallel, mEPSC frequency was increased in Math1Cre;Nf2fl/fl mice. On the contrary, VGluT2 clusters in cerebellar glomeruli composed of NF2-deficient presynaptic Mossy fiber terminals and NF2-deficient postsynaptic GC were reduced in size as shown for isoform-specific knockout mice. These changes in Math1Cre;Nf2fl/fl-deficient mice were paralleled by an increased activation of Rac1-Cofilin signaling which is known to impact on cytoskeletal reorganization and synapse formation. Consistent with the observed synaptic alterations in these transgenic mice, we observed altered ultrasonic vocalization, which is known to rely on proper cerebellar function. No gross morphological changes or motor coordination deficits were observed in any of these transgenic mice. We therefore conclude that Merlin does not regulate overall cerebellar development, but impacts on pre- and post-synaptic terminal organization.
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Affiliation(s)
- A Toledo
- Institute of Anatomy, Anatomy and Cell Biology, Bonn University, 53115, Bonn, Germany
| | - F Lang
- Institute of Anatomy, Anatomy and Cell Biology, Bonn University, 53115, Bonn, Germany
| | - M Doengi
- Institute of Physiology II, Bonn University, 53115, Bonn, Germany
| | - H Morrison
- Leibniz Institute for Age Research, Fritz Lipmann Institute, 07745, Jena, Germany
| | - V Stein
- Institute of Physiology II, Bonn University, 53115, Bonn, Germany
| | - S L Baader
- Institute of Anatomy, Anatomy and Cell Biology, Bonn University, 53115, Bonn, Germany.
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14
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Litan A, Li Z, Tokhtaeva E, Kelly P, Vagin O, Langhans SA. A Functional Interaction Between Na,K-ATPase β 2-Subunit/AMOG and NF2/Merlin Regulates Growth Factor Signaling in Cerebellar Granule Cells. Mol Neurobiol 2019; 56:7557-7571. [PMID: 31062247 DOI: 10.1007/s12035-019-1592-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 04/02/2019] [Indexed: 10/26/2022]
Abstract
The Na,K-ATPase, consisting of a catalytic α-subunit and a regulatory β-subunit, is a ubiquitously expressed ion pump that carries out the transport of Na+ and K+ across the plasma membranes of most animal cells. In addition to its pump function, Na,K-ATPase serves as a signaling scaffold and a cell adhesion molecule. Of the three β-subunit isoforms, β1 is found in almost all tissues, while β2 expression is mostly restricted to brain and muscle. In cerebellar granule cells, the β2-subunit, also known as adhesion molecule on glia (AMOG), has been linked to neuron-astrocyte adhesion and granule cell migration, suggesting its role in cerebellar development. Nevertheless, little is known about molecular pathways that link the β2-subunit to its cellular functions. Using cerebellar granule precursor cells, we found that the β2-subunit, but not the β1-subunit, negatively regulates the expression of a key activator of the Hippo/YAP signaling pathway, Merlin/neurofibromin-2 (NF2). The knockdown of the β2-subunit resulted in increased Merlin/NF2 expression and affected downstream targets of Hippo signaling, i.e., increased YAP phosphorylation and decreased expression of N-Ras. Further, the β2-subunit knockdown altered the kinetics of epidermal growth factor receptor (EGFR) signaling in a Merlin-dependent mode and impaired EGF-induced reorganization of the actin cytoskeleton. Therefore, our studies for the first time provide a functional link between the Na,K-ATPase β2-subunit and Merlin/NF2 and suggest a role for the β2-subunit in regulating cytoskeletal dynamics and Hippo/YAP signaling during neuronal differentiation.
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Affiliation(s)
- Alisa Litan
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, DuPont Experimental Station, Bldg 400, #4414, 200 Powder Mill Road, Wilmington, DE, 19803, USA.,Biological Sciences Graduate Program, University of Delaware, Newark, DE, 19716, USA
| | - Zhiqin Li
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, DuPont Experimental Station, Bldg 400, #4414, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Elmira Tokhtaeva
- David Geffen School of Medicine, University of California, Los Angeles, and VA Greater Los Angeles Health Care System, Los Angeles, CA, 90073, USA
| | - Patience Kelly
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, DuPont Experimental Station, Bldg 400, #4414, 200 Powder Mill Road, Wilmington, DE, 19803, USA.,Biological Sciences Graduate Program, University of Delaware, Newark, DE, 19716, USA
| | - Olga Vagin
- David Geffen School of Medicine, University of California, Los Angeles, and VA Greater Los Angeles Health Care System, Los Angeles, CA, 90073, USA
| | - Sigrid A Langhans
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, DuPont Experimental Station, Bldg 400, #4414, 200 Powder Mill Road, Wilmington, DE, 19803, USA.
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15
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Ferner RE, Bakker A, Elgersma Y, Evans DGR, Giovannini M, Legius E, Lloyd A, Messiaen LM, Plotkin S, Reilly KM, Schindeler A, Smith MJ, Ullrich NJ, Widemann B, Sherman LS. From process to progress-2017 International Conference on Neurofibromatosis 1, Neurofibromatosis 2 and Schwannomatosis. Am J Med Genet A 2019; 179:1098-1106. [PMID: 30908866 DOI: 10.1002/ajmg.a.61112] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 02/09/2019] [Indexed: 12/19/2022]
Abstract
The neurofibromatoses are inherited, tumor suppressor disorders that are characterized by multiple, benign peripheral nerve sheath tumors and other nervous system tumors. Each disease is associated with a distinct genetic mutation and with a different pathogenesis and clinical course. Neurofibromatosis 1 (NF1) is common and epitomized by multiple neurofibromas with widespread complications. NF2 and schwannomatosis are rare diseases that are typified by multiple schwannomas that are particularly painful in people with schwannomatosis. Since 1985, the Children's Tumor Foundation (formerly the National Neurofibromatosis Foundation) has hosted an international Neurofibromatosis Conference, bringing together international participants who are focused on NF research and clinical care. The 2017 Conference, held in Washington, DC, was among the largest gatherings of NF researchers to date and included presentations from clinicians and basic scientists, highlighting new data regarding the molecular and cellular mechanisms underlying each of these diseases as well as results from clinical studies and clinical trials. This article summarizes the findings presented at the meeting and represents the current state-of-the art for NF research.
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Affiliation(s)
- Rosalie E Ferner
- Department of Neurology, Neurofibromatosis Centre, Guy's and St. Thomas' NHS Foundation Trust, and King's College London, London, UK
| | | | - Ype Elgersma
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, The Netherlands
| | - D Gareth R Evans
- Centre for Genomic Medicine, St. Mary's Hospital, Manchester, UK.,Manchester Academic Health Sciences Centre (MAHSC), Division of Evolution and Genomic Science, University of Manchester, Manchester, UK
| | - Marco Giovannini
- Department of Head and Neck Surgery, University of California, Los Angeles
| | - Eric Legius
- Department of Human Genetics, University Hospital Leuven, Leuven, Herestraat, Belgium
| | - Alison Lloyd
- Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Ludwine M Messiaen
- Medical Genomics Laboratory, Department of Genetics, University of Alabama, Birmingham, Alabama
| | - Scott Plotkin
- Department of Neurology and Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Karlyne M Reilly
- Rare Tumors Initiative, Center for Cancer Research, National Institutes of Health, Bethesda, Maryland
| | - Aaron Schindeler
- Orthopaedic Research & Biotechnology, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Miriam J Smith
- Centre for Genomic Medicine, St. Mary's Hospital, Manchester, UK.,Manchester Academic Health Sciences Centre (MAHSC), Division of Evolution and Genomic Science, University of Manchester, Manchester, UK
| | - Nicole J Ullrich
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brigitte Widemann
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Larry S Sherman
- Division of Neuroscience, Oregon National Primate Research Center, and Department of Cell, Developmental and Cancer Biology, Oregon Health & Science University, Portland, Oregon
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16
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Toledo A, Grieger E, Karram K, Morrison H, Baader SL. Neurofibromatosis type 2 tumor suppressor protein is expressed in oligodendrocytes and regulates cell proliferation and process formation. PLoS One 2018; 13:e0196726. [PMID: 29715273 PMCID: PMC5929554 DOI: 10.1371/journal.pone.0196726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 04/18/2018] [Indexed: 12/25/2022] Open
Abstract
The neurofibromatosis type 2 (NF2) tumor suppressor protein Merlin functions as a negative regulator of cell growth and actin dynamics in different cell types amongst which Schwann cells have been extensively studied. In contrast, the presence and the role of Merlin in oligodendrocytes, the myelin forming cells within the CNS, have not been elucidated. In this work, we demonstrate that Merlin immunoreactivity was broadly distributed in the white matter throughout the central nervous system. Following Merlin expression during development in the cerebellum, Merlin could be detected in the cerebellar white matter tract at early postnatal stages as shown by its co-localization with Olig2-positive cells as well as in adult brain sections where it was aligned with myelin basic protein containing fibers. This suggests that Merlin is expressed in immature and mature oligodendrocytes. Expression levels of Merlin were low in oligodendrocytes as compared to astrocytes and neurons throughout development. Expression of Merlin in oligodendroglia was further supported by its identification in either immortalized cell lines of oligodendroglial origin or in primary oligodendrocyte cultures. In these cultures, the two main splice variants of Nf2 could be detected. Merlin was localized in clusters within the nuclei and in the cytoplasm. Overexpressing Merlin in oligodendrocyte cell lines strengthened reduced impedance in XCELLigence measurements and Ki67 stainings in cultures over time. In addition, the initiation and elongation of cellular projections were reduced by Merlin overexpression. Consistently, cell migration was retarded in scratch assays done on Nf2-transfected oligodendrocyte cell lines. These data suggest that Merlin actively modulates process outgrowth and migration in oligodendrocytes.
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Affiliation(s)
- Andrea Toledo
- Institute of Anatomy, Anatomy and Cell Biology, Bonn, Germany
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, UdelaR, Montevideo, Uruguay
| | - Elena Grieger
- Institute of Anatomy, Anatomy and Cell Biology, Bonn, Germany
| | - Khalad Karram
- Institute for Molecular Medicine, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Helen Morrison
- Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena, Germany
| | - Stephan L. Baader
- Institute of Anatomy, Anatomy and Cell Biology, Bonn, Germany
- * E-mail:
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17
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Riecken LB, Zoch A, Wiehl U, Reichert S, Scholl I, Cui Y, Ziemer M, Anderegg U, Hagel C, Morrison H. CPI-17 drives oncogenic Ras signaling in human melanomas via Ezrin-Radixin-Moesin family proteins. Oncotarget 2018; 7:78242-78254. [PMID: 27793041 PMCID: PMC5346635 DOI: 10.18632/oncotarget.12919] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 10/21/2016] [Indexed: 01/12/2023] Open
Abstract
Hyperactive Ras signaling has strong oncogenic effects causing several different forms of cancer. Hyperactivity is frequently induced by mutations within Ras itself, which account for up to 30% of all human cancers. In addition, hyperactive Ras signaling can also be triggered independent of Ras by either mutation or by misexpression of various upstream regulators and immediate downstream effectors. We have previously reported that C-kinase potentiated protein phosphatase-1 inhibitor of 17 kDa (CPI-17) can drive Ras activity and promote tumorigenic transformation by inhibition of the tumor suppressor Merlin. We now describe an additional element of this oncogenic mechanism in the form of the ezrin-radixin-moesin (ERM) protein family, which exhibits opposing roles in Ras activity control. Thus, CPI-17 drives Ras activity and tumorigenesis in a two-fold way; inactivation of the tumor suppressor merlin and activation of the growth promoting ERM family. The in vivo significance of this oncogenic switch is highlighted by demonstrating CPI-17's involvement in human melanoma pathogenesis.
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Affiliation(s)
| | - Ansgar Zoch
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Ulrike Wiehl
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Sabine Reichert
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany.,Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Ingmar Scholl
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Yan Cui
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Mirjana Ziemer
- Klinik und Poliklinik für Dermatologie, Venerologie und Allergologie, Universität Leipzig, Leipzig, Germany
| | - Ulf Anderegg
- Klinik und Poliklinik für Dermatologie, Venerologie und Allergologie, Universität Leipzig, Leipzig, Germany
| | - Christian Hagel
- Department of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Helen Morrison
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
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18
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Nf2 Mutation in Schwann Cells Delays Functional Neural Recovery Following Injury. Neuroscience 2018; 374:205-213. [PMID: 29408605 DOI: 10.1016/j.neuroscience.2018.01.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 11/21/2022]
Abstract
Merlin is the protein product of the NF2 tumor suppressor gene. Germline NF2 mutation leads to neurofibromatosis type 2 (NF2), characterized by multiple intracranial and spinal schwannomas. Patients with NF2 also frequently develop peripheral neuropathies. While the role of merlin in SC neoplasia is well established, its role in SC homeostasis is less defined. Here we explore the role of merlin in SC responses to nerve injury and their ability to support axon regeneration. We performed sciatic nerve crush in wild-type (WT) and in P0SchΔ39-121 transgenic mice that express a dominant negative Nf2 isoform in SCs. Recovery of nerve function was assessed by measuring mean contact paw area on a pressure pad 7, 21, 60, and 90 days following nerve injury and by nerve conduction assays at 90 days following injury. After 90 days, the nerves were harvested and axon regeneration was quantified stereologically. Myelin ultrastructure was analyzed by electron microscopy. Functional studies showed delayed nerve regeneration in Nf2 mutant mice compared to the WT mice. Delayed neural recovery correlated with a reduced density of regenerated axons and increased endoneurial space in mutants compared to WT mice. Nevertheless, functional and nerve conduction measures ultimately recovered to similar levels in WT and Nf2 mutant mice, while there was a small (∼17%) reduction in the percent of regenerated axons in the Nf2 mutant mice. The data suggest that merlin function in SCs regulates neural ultrastructure and facilitates neural regeneration, in addition to its role in SC neoplasia.
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19
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Neuropathies in the setting of Neurofibromatosis tumor syndromes: Complexities and opportunities. Exp Neurol 2017; 299:334-344. [PMID: 28587874 DOI: 10.1016/j.expneurol.2017.06.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 05/03/2017] [Accepted: 06/02/2017] [Indexed: 12/11/2022]
Abstract
The term 'Neurofibromatosis' (NF) comprises a group of rare diseases with related clinical presentations but distinct genetic conditions. All currently known types - NF1, NF2 and Schwannomatosis - predispose afflicted individuals to the development of glial cell-derived (gliogenic) tumors. Furthermore, the occurrence of neuropathic symptoms, which add to the overall neurologic disability of patients, has been described in all disease entities. We show that neuropathic symptoms are a common and clinically important, yet infrequently studied feature in the NF spectrum. However, the clinical relevance and respective underlying pathogenesis, varies greatly among the different NF types. In this review, we summarize and interpret the latest basic research findings, as well as clinical observations, in respect of Neurofibromatosis-associated neuropathies.
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20
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Abstract
Neoplasms in the central (CNS) and peripheral nervous system (PNS) in hereditary tumor syndromes play an important role in the neuropathological diagnostics. The benign and malignant PNS and CNS tumors that occur in the frequent neurofibromatosis type 1 (NF1) and type 2 (NF2) often represent essential factors for the course of the disease in those affected. Furthermore, certain clinical constellations (e.g. bilateral schwannomas of the auditory nerve, schwannomas at a young age and multiple meningiomas) can be important indications for a previously undiagnosed hereditary tumor disease. Other tumors occur practically regularly in association with certain germline defects, e.g. subependymal giant cell astrocytoma (SEGA) in tuberous sclerosis and dysplastic gangliocytoma of the cerebellum in Cowden's syndrome and can be indications in the diagnostics for an extended genetic counselling. This is not only important because many germline defects are based on new mutations, but also for the now established targeted therapy of certain tumors, e.g. inhibition of the mammalian target of rapamycin (mTOR) signaling pathway using temsirolimus for SEGA. Furthermore, knowledge about the possible constellations of genetic mosaics in hereditary tumor syndromes with the resulting (incomplete) syndrome manifestations is useful. This review article summarizes the most important hereditary tumor syndromes with involvement of the PNS and CNS.
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Affiliation(s)
- C Mawrin
- Institut für Neuropathologie, Otto-von-Guericke-Universität Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Deutschland.
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21
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Weis J, Claeys KG, Roos A, Azzedine H, Katona I, Schröder JM, Senderek J. Towards a functional pathology of hereditary neuropathies. Acta Neuropathol 2017; 133:493-515. [PMID: 27896434 DOI: 10.1007/s00401-016-1645-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 11/10/2016] [Accepted: 11/13/2016] [Indexed: 12/11/2022]
Abstract
A growing number of hereditary neuropathies have been assigned to causative gene defects in recent years. The study of human nerve biopsy samples has contributed substantially to the discovery of many of these neuropathy genes. Genotype-phenotype correlations based on peripheral nerve pathology have provided a comprehensive picture of the consequences of these mutations. Intriguingly, several gene defects lead to distinguishable lesion patterns that can be studied in nerve biopsies. These characteristic features include the loss of certain nerve fiber populations and a large spectrum of distinct structural changes of axons, Schwann cells and other components of peripheral nerves. In several instances the lesion patterns are directly or indirectly linked to the known functions of the mutated gene. The present review is designed to provide an overview on these characteristic patterns. It also considers other aspects important for the manifestation and pathology of hereditary neuropathies including the role of inflammation, effects of chemotherapeutic agents and alterations detectable in skin biopsies.
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Affiliation(s)
- Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany.
| | - Kristl G Claeys
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
- Department of Neurology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
- Department of Neurology, University Hospitals Leuven and University of Leuven (KU Leuven), Leuven, Belgium
| | - Andreas Roos
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Hamid Azzedine
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Istvan Katona
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
| | - J Michael Schröder
- Institute of Neuropathology, RWTH Aachen University Medical School, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Jan Senderek
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University, Ziemssenstr. 1a, 80336, Munich, Germany.
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22
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Mindos T, Dun XP, North K, Doddrell RDS, Schulz A, Edwards P, Russell J, Gray B, Roberts SL, Shivane A, Mortimer G, Pirie M, Zhang N, Pan D, Morrison H, Parkinson DB. Merlin controls the repair capacity of Schwann cells after injury by regulating Hippo/YAP activity. J Cell Biol 2017; 216:495-510. [PMID: 28137778 PMCID: PMC5294779 DOI: 10.1083/jcb.201606052] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/23/2016] [Accepted: 12/27/2016] [Indexed: 02/06/2023] Open
Abstract
The regenerative capacity of Schwann cells in the PNS underlies functional repair after injury. In this study, Mindos et al. show a new function for the tumor suppressor Merlin and Hippo/YAP signaling in the generation of repair-competent Schwann cells after injury. Loss of the Merlin tumor suppressor and activation of the Hippo signaling pathway play major roles in the control of cell proliferation and tumorigenesis. We have identified completely novel roles for Merlin and the Hippo pathway effector Yes-associated protein (YAP) in the control of Schwann cell (SC) plasticity and peripheral nerve repair after injury. Injury to the peripheral nervous system (PNS) causes a dramatic shift in SC molecular phenotype and the generation of repair-competent SCs, which direct functional repair. We find that loss of Merlin in these cells causes a catastrophic failure of axonal regeneration and remyelination in the PNS. This effect is mediated by activation of YAP expression in Merlin-null SCs, and loss of YAP restores axonal regrowth and functional repair. This work identifies new mechanisms that control the regenerative potential of SCs and gives new insight into understanding the correct control of functional nerve repair in the PNS.
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Affiliation(s)
- Thomas Mindos
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Xin-Peng Dun
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Katherine North
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK.,University of Bath, Bath BA2 7AY, England, UK
| | - Robin D S Doddrell
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Alexander Schulz
- Leibniz Institute for Age Research - Fritz Lipmann Institute Jena, D-07745 Jena, Germany
| | - Philip Edwards
- Department of Cellular and Anatomical Pathology, Derriford Hospital, Plymouth PL6 8DH, England, UK
| | - James Russell
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Bethany Gray
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK.,University of Bath, Bath BA2 7AY, England, UK
| | - Sheridan L Roberts
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Aditya Shivane
- Department of Cellular and Anatomical Pathology, Derriford Hospital, Plymouth PL6 8DH, England, UK
| | - Georgina Mortimer
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Melissa Pirie
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
| | - Nailing Zhang
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Duojia Pan
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Helen Morrison
- Leibniz Institute for Age Research - Fritz Lipmann Institute Jena, D-07745 Jena, Germany
| | - David B Parkinson
- Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth PL6 8BU, England, UK
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23
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Farschtschi S, Gelderblom M, Buschbaum S, Bostock H, Grafe P, Mautner VF. Muscle action potential scans and ultrasound imaging in neurofibromatosis type 2. Muscle Nerve 2016; 55:350-358. [PMID: 27422240 DOI: 10.1002/mus.25256] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2016] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The neuropathy in patients with neurofibromatosis type 2 (NF2) is difficult to quantify and follow up. In this study we compared 3 methods that may help assess motor axon pathology in NF2 patients. METHODS Nerve conduction studies in median nerves were supplemented by deriving motor unit number estimates (MUNEs) from compound muscle action potential (CMAP) scans and by high-resolution ultrasound (US) peripheral nerve imaging. RESULTS CMAP amplitudes and nerve conduction velocity were normal in the vast majority of affected individuals, but CMAP scan MUNE revealed denervation and reinnervation in many peripheral nerves. In addition, nerve US imaging enabled monitoring of the size and number of schwannoma-like fascicular enlargements in median nerve trunks. CONCLUSION In contrast to conventional nerve conduction studies, CMAP scan MUNE in combination with US nerve imaging can quantify the NF2-associated neuropathy and may help to monitor disease progression and drug treatments. Muscle Nerve 55: 350-358, 2017.
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Affiliation(s)
- Said Farschtschi
- Department of Neurology, University Medical Centre Hamburg-Eppendorf Hospital, Hamburg, Germany
| | - Mathias Gelderblom
- Department of Neurology, University Medical Centre Hamburg-Eppendorf Hospital, Hamburg, Germany
| | - Sabriena Buschbaum
- Department of Neurology, University Medical Centre Hamburg-Eppendorf Hospital, Hamburg, Germany
| | - Hugh Bostock
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Peter Grafe
- Physiological Genomics, Institute of Physiology, Ludwig-Maximilians University Munich, Pettenkoferstrasse 12, 80336, Munich, Germany
| | - Victor F Mautner
- Department of Neurology, University Medical Centre Hamburg-Eppendorf Hospital, Hamburg, Germany
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24
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The Caenorhabditis elegans NF2/Merlin Molecule NFM-1 Nonautonomously Regulates Neuroblast Migration and Interacts Genetically with the Guidance Cue SLT-1/Slit. Genetics 2016; 205:737-748. [PMID: 27913619 DOI: 10.1534/genetics.116.191957] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 11/23/2016] [Indexed: 11/18/2022] Open
Abstract
During nervous system development, neurons and their progenitors migrate to their final destinations. In Caenorhabditis elegans, the bilateral Q neuroblasts and their descendants migrate long distances in opposite directions, despite being born in the same posterior region. QR on the right migrates anteriorly and generates the AQR neuron positioned near the head, and QL on the left migrates posteriorly, giving rise to the PQR neuron positioned near the tail. In a screen for genes required for AQR and PQR migration, we identified an allele of nfm-1, which encodes a molecule similar to vertebrate NF2/Merlin, an important tumor suppressor in humans. Mutations in NF2 lead to neurofibromatosis type II, characterized by benign tumors of glial tissues. Here we demonstrate that in C. elegans, nfm-1 is required for the ability of Q cells and their descendants to extend protrusions and to migrate, but is not required for direction of migration. Using a combination of mosaic analysis and cell-specific expression, we show that NFM-1 is required nonautonomously, possibly in muscles, to promote Q lineage migrations. We also show a genetic interaction between nfm-1 and the C. elegans Slit homolog slt-1, which encodes a conserved secreted guidance cue. Our results suggest that NFM-1 might be involved in the generation of an extracellular cue that promotes Q neuroblast protrusion and migration that acts with or in parallel to SLT-1 In vertebrates, NF2 and Slit2 interact in axon pathfinding, suggesting a conserved interaction of NF2 and Slit2 in regulating migratory events.
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25
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Méphon-Gaspard A, Boca M, Pioche-Durieu C, Desforges B, Burgo A, Hamon L, Piétrement O, Pastré D. Role of tau in the spatial organization of axonal microtubules: keeping parallel microtubules evenly distributed despite macromolecular crowding. Cell Mol Life Sci 2016; 73:3745-60. [PMID: 27076215 PMCID: PMC5002045 DOI: 10.1007/s00018-016-2216-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 03/24/2016] [Accepted: 04/01/2016] [Indexed: 02/07/2023]
Abstract
Opposing views have been proposed regarding the role of tau, the principal microtubule-associated protein in axons. On the one hand, tau forms cross-bridges at the interface between microtubules and induces microtubule bundling in neurons. On the other hand, tau is also considered a polymer brush which efficiently separates microtubules. In mature axons, microtubules are indeed arranged in parallel arrays and are well separated from each other. To reconcile these views, we developed a mechanistic model based on in vitro and cellular approaches combined to analytical and numerical analyses. The results indicate that tau forms long-range cross-bridges between microtubules under macromolecular crowding conditions. Tau cross-bridges prevent the redistribution of tau away from the interface between microtubules, which would have occurred in the polymer brush model. Consequently, the short-range attractive force between microtubules induced by macromolecular crowding is avoided and thus microtubules remain well separated from each other. Interestingly, in this unified model, tau diffusion on microtubules enables to keep microtubules evenly distributed in axonal sections at low tau levels.
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Affiliation(s)
- Alix Méphon-Gaspard
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Mirela Boca
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Catherine Pioche-Durieu
- UMR 8126, CNRS, Gustave Roussy Université Paris Sud, Université Paris-Saclay, Villejuif, 94805, France
| | - Bénédicte Desforges
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Andrea Burgo
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Loic Hamon
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Olivier Piétrement
- UMR 8126, CNRS, Gustave Roussy Université Paris Sud, Université Paris-Saclay, Villejuif, 94805, France
| | - David Pastré
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France.
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26
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Schulz A, Büttner R, Hagel C, Baader SL, Kluwe L, Salamon J, Mautner VF, Mindos T, Parkinson DB, Gehlhausen JR, Clapp DW, Morrison H. The importance of nerve microenvironment for schwannoma development. Acta Neuropathol 2016; 132:289-307. [PMID: 27236462 PMCID: PMC4947119 DOI: 10.1007/s00401-016-1583-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 05/18/2016] [Accepted: 05/21/2016] [Indexed: 11/22/2022]
Abstract
Schwannomas are predominantly benign nerve sheath neoplasms caused by Nf2 gene inactivation. Presently, treatment options are mainly limited to surgical tumor resection due to the lack of effective pharmacological drugs. Although the mechanistic understanding of Nf2 gene function has advanced, it has so far been primarily restricted to Schwann cell-intrinsic events. Extracellular cues determining Schwann cell behavior with regard to schwannoma development remain unknown. Here we show pro-tumourigenic microenvironmental effects on Schwann cells where an altered axonal microenvironment in cooperation with injury signals contribute to a persistent regenerative Schwann cell response promoting schwannoma development. Specifically in genetically engineered mice following crush injuries on sciatic nerves, we found macroscopic nerve swellings in mice with homozygous nf2 gene deletion in Schwann cells and in animals with heterozygous nf2 knockout in both Schwann cells and axons. However, patient-mimicking schwannomas could only be provoked in animals with combined heterozygous nf2 knockout in Schwann cells and axons. We identified a severe re-myelination defect and sustained macrophage presence in the tumor tissue as major abnormalities. Strikingly, treatment of tumor-developing mice after nerve crush injury with medium-dose aspirin significantly decreased schwannoma progression in this disease model. Our results suggest a multifactorial concept for schwannoma formation—emphasizing axonal factors and mechanical nerve irritation as predilection site for schwannoma development. Furthermore, we provide evidence supporting the potential efficacy of anti-inflammatory drugs in the treatment of schwannomas.
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27
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Neuron-Specific Deletion of the Nf2 Tumor Suppressor Impairs Functional Nerve Regeneration. PLoS One 2016; 11:e0159718. [PMID: 27467574 PMCID: PMC4965074 DOI: 10.1371/journal.pone.0159718] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/07/2016] [Indexed: 12/20/2022] Open
Abstract
In contrast to axons of the central nervous system (CNS), axons of the peripheral nervous system (PNS) show better, but still incomplete and often slow regeneration following injury. The tumor suppressor protein merlin, mutated in the hereditary tumor syndrome Neurofibromatosis type 2 (NF2), has recently been shown to have RhoA regulatory functions in PNS neurons—in addition to its well-characterized, growth-inhibitory activity in Schwann cells. Here we report that the conditional knockout of merlin in PNS neurons leads to impaired functional recovery of mice following sciatic nerve crush injury, in a gene-dosage dependent manner. Gross anatomical or electrophysiological alterations of sciatic nerves could not be detected. However, correlating with attenuated RhoA activation due to merlin deletion, ultrastructural analysis of nerve samples indicated enhanced sprouting of axons with reduced caliber size and increased myelination compared to wildtype animals. We conclude that deletion of the tumor suppressor merlin in the neuronal compartment of peripheral nerves results in compromised functional regeneration after injury. This mechanism could explain the clinical observation that NF2 patients suffer from higher incidences of slowly recovering facial nerve paralysis after vestibular schwannoma surgery.
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28
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Fuller HR, Marani L, Holt I, Woodhams PL, Webb MM, Gates MA. Monoclonal antibody Py recognizes neurofilament heavy chain and is a selective marker for large diameter neurons in the brain. Brain Struct Funct 2016; 222:867-879. [PMID: 27311890 DOI: 10.1007/s00429-016-1252-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/08/2016] [Indexed: 01/04/2023]
Abstract
Almost 30 years ago, the monoclonal antibody Py was developed to detect pyramidal neurons in the CA3 region of the rat hippocampus. The utility of this antibody quickly expanded when several groups discovered that it could be used to identify very specific populations of neurons in the normal, developing, and diseased or injured central nervous system. Despite this body of literature, the identity of the antigen that the Py antibody recognizes remained elusive. Here, immunoprecipitation experiments from the adult rat cortex identified the Py antigen as neurofilament heavy chain (NF-H). Double immunolabeling of sections through the rat brain using Py and NF-H antibodies confirmed the identity of the Py antigen, and reveal that Py/NF-H+ neurons appear to share the feature of being particularly large in diameter. These include the neurons of the gigantocellular reticular formation, pyramidal neurons of layers II/III and V of the cortex, cerebellar Purkinje neurons as well as CA3 pyramidal neurons. Taken together, this finding gives clarity to past work using the monoclonal Py antibody, and immediately expands our understanding of the importance of NF-H in neural development, functioning, and disease.
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Affiliation(s)
- Heidi R Fuller
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK
- Institute for Science and Technology in Medicine, Keele University, Staffordshire, ST5 5BG, UK
| | - Lucia Marani
- School of Sports, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK
| | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK
- Institute for Science and Technology in Medicine, Keele University, Staffordshire, ST5 5BG, UK
| | - Peter L Woodhams
- National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
| | - Michael M Webb
- Mitobridge Inc, 1030 Massachusetts Avenue, Cambridge, MA, 02138, USA
| | - Monte A Gates
- Institute for Science and Technology in Medicine, Keele University, Staffordshire, ST5 5BG, UK.
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29
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Bakker AC, La Rosa S, Sherman LS, Knight P, Lee H, Pancza P, Nievo M. Neurofibromatosis as a gateway to better treatment for a variety of malignancies. Prog Neurobiol 2016; 152:149-165. [PMID: 26854064 DOI: 10.1016/j.pneurobio.2016.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 01/25/2016] [Accepted: 01/25/2016] [Indexed: 12/23/2022]
Abstract
The neurofibromatoses (NF) are a group of rare genetic disorders that can affect all races equally at an incidence from 1:3000 (NF1) to a log unit lower for NF2 and schwannomatosis. Since the research community is reporting an increasing number of malignant cancers that carry mutations in the NF genes, the general interest of both the research and pharma community is increasing and the authors saw an opportunity to present a novel, fresh approach to drug discovery in NF. The aim of the paper is to challenge the current drug discovery approach to NF, whereby existing targeted therapies that are either in the clinic or on the market for other disease indications are repurposed for NF. We offer a suggestion for an alternative drug discovery approach. In the new approach, selective and tolerable targeted therapies would be developed for NF and later expanded to patients with more complex diseases such as malignant cancer in which the NF downstream pathways are deregulated. The Children's Tumor Foundation, together with some other major NF funders, is playing a key role in funding critical initiatives that will accelerate the development of better targeted therapies for NF patients, while these novel, innovative treatments could potentially be beneficial to molecularly characterized cancer patients in which NF mutations have been identified.
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Affiliation(s)
- Annette C Bakker
- Children's Tumor Foundation, 120, Wall Street, 16th Floor, New York 10005, United States
| | - Salvatore La Rosa
- Children's Tumor Foundation, 120, Wall Street, 16th Floor, New York 10005, United States
| | - Larry S Sherman
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, United States
| | - Pamela Knight
- Children's Tumor Foundation, 120, Wall Street, 16th Floor, New York 10005, United States
| | - Hyerim Lee
- Children's Tumor Foundation, 120, Wall Street, 16th Floor, New York 10005, United States
| | - Patrice Pancza
- Children's Tumor Foundation, 120, Wall Street, 16th Floor, New York 10005, United States
| | - Marco Nievo
- Children's Tumor Foundation, 120, Wall Street, 16th Floor, New York 10005, United States.
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30
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Petrilli AM, Fernández-Valle C. Role of Merlin/NF2 inactivation in tumor biology. Oncogene 2016; 35:537-48. [PMID: 25893302 PMCID: PMC4615258 DOI: 10.1038/onc.2015.125] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 02/20/2015] [Accepted: 03/16/2015] [Indexed: 01/13/2023]
Abstract
Merlin (Moesin-ezrin-radixin-like protein, also known as schwannomin) is a tumor suppressor protein encoded by the neurofibromatosis type 2 gene NF2. Loss of function mutations or deletions in NF2 cause neurofibromatosis type 2 (NF2), a multiple tumor forming disease of the nervous system. NF2 is characterized by the development of bilateral vestibular schwannomas. Patients with NF2 can also develop schwannomas on other cranial and peripheral nerves, as well as meningiomas and ependymomas. The only potential treatment is surgery/radiosurgery, which often results in loss of function of the involved nerve. There is an urgent need for chemotherapies that slow or eliminate tumors and prevent their formation in NF2 patients. Interestingly NF2 mutations and merlin inactivation also occur in spontaneous schwannomas and meningiomas, as well as other types of cancer including mesothelioma, glioma multiforme, breast, colorectal, skin, clear cell renal cell carcinoma, hepatic and prostate cancer. Except for malignant mesotheliomas, the role of NF2 mutation or inactivation has not received much attention in cancer, and NF2 might be relevant for prognosis and future chemotherapeutic approaches. This review discusses the influence of merlin loss of function in NF2-related tumors and common human cancers. We also discuss the NF2 gene status and merlin signaling pathways affected in the different tumor types and the molecular mechanisms that lead to tumorigenesis, progression and pharmacological resistance.
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Affiliation(s)
- Alejandra M. Petrilli
- Department of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Cristina Fernández-Valle
- Department of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
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31
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Merlin Isoforms 1 and 2 Both Act as Tumour Suppressors and Are Required for Optimal Sperm Maturation. PLoS One 2015; 10:e0129151. [PMID: 26258444 PMCID: PMC4530865 DOI: 10.1371/journal.pone.0129151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 05/05/2015] [Indexed: 12/14/2022] Open
Abstract
The tumour suppressor Merlin, encoded by the gene NF2, is frequently mutated in the autosomal dominant disorder neurofibromatosis type II, characterised primarily by the development of schwannoma and other glial cell tumours. However, NF2 is expressed in virtually all analysed human and rodent organs, and its deletion in mice causes early embryonic lethality. Additionally, NF2 encodes for two major isoforms of Merlin of unknown functionality. Specifically, the tumour suppressor potential of isoform 2 remains controversial. In this study, we used Nf2 isoform-specific knockout mouse models to analyse the function of each isoform during development and organ homeostasis. We found that both isoforms carry full tumour suppressor functionality and can completely compensate the loss of the other isoform during development and in most adult organs. Surprisingly, we discovered that spermatogenesis is strictly dependent on the presence of both isoforms. While the testis primarily expresses isoform 1, we noticed an enrichment of isoform 2 in spermatogonial stem cells. Deletion of either isoform was found to cause decreased sperm quality as observed by maturation defects and head/midpiece abnormalities. These defects led to impaired sperm functionality as assessed by decreased sperm capacitation. Thus, we describe spermatogenesis as a new Nf2-dependent process. Additionally, we provide for the first time in vivo evidence for equal tumour suppressor potentials of Merlin isoform 1 and isoform 2.
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Abstract
Type 2 neurofibromatosis (NF2) is an autosomal dominant disorder caused by mutations in the NF2 tumor suppressor gene NF2 on chromosome 22. Around 1 in 33000 people are born with an NF2 mutation although more than one-third of the 60% of de novo cases are not conceived with the mutation but this develops later in embryogenesis (mosaics). NF2 has a substantial effect on life expectancy and individuals with a constitutional truncating mutation have the worst prognosis. The vast majority of people with NF2 will develop bilateral vestibular schwannomas with many developing schwannomas on other cranial, spinal and peripheral nerves. Cranial and spinal meningiomas and intraspinal low grade indolent ependymomas are the other major tumor features. Cutaneous features can be subtle with only 70% having evidence of intracutaneous plaque-like schwannomas or subcutaneous lesions on peripheral nerves. Café-au-lait patches are more frequent than in the general population but in only around 1% will meet NIH criteria for NF1.
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Affiliation(s)
- D G R Evans
- University Department of Genomic Medicine, University of Manchester, St Mary's Hospital, Manchester, UK.
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Lavado A, Ware M, Paré J, Cao X. The tumor suppressor Nf2 regulates corpus callosum development by inhibiting the transcriptional coactivator Yap. Development 2014; 141:4182-93. [PMID: 25336744 DOI: 10.1242/dev.111260] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The corpus callosum connects cerebral hemispheres and is the largest axon tract in the mammalian brain. Callosal malformations are among the most common congenital brain anomalies and are associated with a wide range of neuropsychological deficits. Crossing of the midline by callosal axons relies on a proper midline environment that harbors guidepost cells emitting guidance cues to instruct callosal axon navigation. Little is known about what controls the formation of the midline environment. We find that two components of the Hippo pathway, the tumor suppressor Nf2 (Merlin) and the transcriptional coactivator Yap (Yap1), regulate guidepost development and expression of the guidance cue Slit2 in mouse. During normal brain development, Nf2 suppresses Yap activity in neural progenitor cells to promote guidepost cell differentiation and prevent ectopic Slit2 expression. Loss of Nf2 causes malformation of midline guideposts and Slit2 upregulation, resulting in callosal agenesis. Slit2 heterozygosity and Yap deletion both restore callosal formation in Nf2 mutants. Furthermore, selectively elevating Yap activity in midline neural progenitors is sufficient to disrupt guidepost formation, upregulate Slit2 and prevent midline crossing. The Hippo pathway is known for its role in controlling organ growth and tumorigenesis. Our study identifies a novel role of this pathway in axon guidance. Moreover, by linking axon pathfinding and neural progenitor behaviors, our results provide an example of the intricate coordination between growth and wiring during brain development.
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Affiliation(s)
- Alfonso Lavado
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Michelle Ware
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Joshua Paré
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Xinwei Cao
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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Plotkin SR, Albers AC, Babovic-Vuksanovic D, Blakeley JO, Breakefield XO, Dunn CM, Evans DG, Fisher MJ, Friedman JM, Giovannini M, Gutmann DH, Kalamarides M, McClatchey AI, Messiaen L, Morrison H, Parkinson DB, Stemmer-Rachamimov AO, Van Raamsdonk CD, Riccardi VM, Rosser T, Schindeler A, Smith MJ, Stevenson DA, Ullrich NJ, van der Vaart T, Weiss B, Widemann BC, Zhu Y, Bakker AC, Lloyd AC. Update from the 2013 International Neurofibromatosis Conference. Am J Med Genet A 2014; 164A:2969-78. [PMID: 25255738 PMCID: PMC4236251 DOI: 10.1002/ajmg.a.36754] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 08/14/2014] [Indexed: 12/16/2022]
Affiliation(s)
- Scott R. Plotkin
- Department of Neurology and Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Anne C. Albers
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | | | | | - Xandra O. Breakefield
- Neuroscience Center, Center for Molecular Imaging and Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston, MA
| | - Courtney M. Dunn
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | - D. Gareth Evans
- Center for Genomic Medicine, St Mary's Hospital, Manchester Academic Health Sciences Centre, University of Manchester, UK
| | - Michael J. Fisher
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Jan M. Friedman
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Marco Giovannini
- Center for Neural Tumor Research, House Research Institute, Los Angeles, CA
| | - David H. Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO
| | | | - Andrea I. McClatchey
- Department of Pathology, Massachusetts General Hospital/Harvard Medical School, Boston, MA
| | - Ludwine Messiaen
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL
| | | | - David B. Parkinson
- Centre for Biomedical Research, University of Plymouth, Peninsula College of Medicine and Dentistry, Plymouth, UK
| | | | | | | | - Tena Rosser
- Department of Neurology, Children's Hospital, Los Angeles, University of Southern California
| | - Aaron Schindeler
- Kids' Research Institute, The Children's Hospital at Westmead, University of Sydney, Westmead, Australia
| | - Miriam J. Smith
- Center for Genomic Medicine, St Mary's Hospital, Manchester Academic Health Sciences Centre, University of Manchester, UK
| | - David A. Stevenson
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT
| | - Nicole J. Ullrich
- Departments of Neurology and Pediatric Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | | | - Brian Weiss
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | | | - Yuan Zhu
- Gilbert Neurofibromatosis Institute, Children's National Medical Center, Washington, DC
| | | | - Alison C. Lloyd
- MRC Laboratory for Molecular Cell Biology, University College London, UK
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Serinagaoglu Y, Paré J, Giovannini M, Cao X. Nf2-Yap signaling controls the expansion of DRG progenitors and glia during DRG development. Dev Biol 2014; 398:97-109. [PMID: 25433207 DOI: 10.1016/j.ydbio.2014.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 11/17/2022]
Abstract
Molecular mechanisms governing the maintenance and proliferation of dorsal root ganglia (DRG) progenitors are largely unknown. Here we reveal that the Hippo pathway regulates the expansion of DRG progenitors and glia during mammalian DRG development. The key effectors of this pathway, transcriptional coactivators Yap and Taz, are expressed in DRG progenitors and glia during DRG development but are at least partially inhibited from activating transcription. Aberrant YAP activation leads to overexpansion of DRG progenitor and glial populations. We further show that the Neurofibromatosis 2 (Nf2) tumor suppressor inhibits Yap during DRG development. Loss of Nf2 leads to similar phenotypes as does YAP hyperactivation, and deleting Yap suppresses these phenotypes. Our study demonstrates that Nf2-Yap signaling plays important roles in controlling the expansion of DRG progenitors and glia during DRG development.
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Affiliation(s)
- Yelda Serinagaoglu
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Joshua Paré
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Marco Giovannini
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90057, USA
| | - Xinwei Cao
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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36
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Peyre M, Kalamarides M. Molecular genetics of meningiomas: Building the roadmap towards personalized therapy. Neurochirurgie 2014; 64:22-28. [PMID: 25245924 DOI: 10.1016/j.neuchi.2014.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 06/25/2014] [Accepted: 06/29/2014] [Indexed: 11/17/2022]
Abstract
New advances have recently been made in the field of molecular genetics and mouse modeling of meningiomas, opening new perspectives for future treatments. Recent genome-wide genotyping and exome sequencing studies have confirmed the pivotal role of NF2 in meningioma tumorigenesis, concerning roughly half of the tumors, and unraveled new mutations in non-NF2 meningiomas concerning AKT1, SMO, KLF4 and TRAF7. The molecular mechanisms underlying tumorigenesis of high histological grades have been progressively deciphered with the recent discovery of TERT promoter mutations in progressing tumors. A better understanding of the genetics and clinical behavior of high-grade meningiomas is mandatory in order to better design future clinical trials. New genetically engineered mouse models of benign and histologically aggressive meningioma represent a substantial resource for the establishment of relevant pre-clinical trials. By studying the mechanisms underlying these new tumorigenesis pathways and the corresponding mouse models, we should be able to offer personalized chemotherapy to patients with surgery- and radiation-refractory meningiomas in the near future.
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Affiliation(s)
- M Peyre
- Service de Neurochirurgie, AP-HP, Hôpital Pitié Salpêtrière, 47-83, boulevard de l'Hôpital, 75013 Paris, France; Inserm, UMR S975, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Université Paris 6 - Pierre-et-Marie-Curie, 75013 Paris, France
| | - M Kalamarides
- Service de Neurochirurgie, AP-HP, Hôpital Pitié Salpêtrière, 47-83, boulevard de l'Hôpital, 75013 Paris, France; Inserm, UMR S975, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Université Paris 6 - Pierre-et-Marie-Curie, 75013 Paris, France.
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37
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Garcia C, Gutmann DH. Using the neurofibromatosis tumor predisposition syndromes to understand normal nervous system development. SCIENTIFICA 2014; 2014:915725. [PMID: 25243094 PMCID: PMC4163293 DOI: 10.1155/2014/915725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 05/07/2014] [Indexed: 06/03/2023]
Abstract
Development is a tightly regulated process that involves stem cell self-renewal, differentiation, cell-to-cell communication, apoptosis, and blood vessel formation. These coordinated processes ensure that tissues maintain a size and architecture that is appropriate for normal tissue function. As such, tumors arise when cells acquire genetic mutations that allow them to escape the normal growth constraints. In this regard, the study of tumor predisposition syndromes affords a unique platform to better understand normal development and the process by which normal cells transform into cancers. Herein, we review the processes governing normal brain development, discuss how brain cancer represents a disruption of these normal processes, and highlight insights into both normal development and cancer made possible by the study of tumor predisposition syndromes.
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Affiliation(s)
- Cynthia Garcia
- Department of Neurology, Washington University School of Medicine, Box 8111, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - David H. Gutmann
- Department of Neurology, Washington University School of Medicine, Box 8111, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Su ZH, Liu YN, Wang RH, Qiao JW, Xie YL. Regulatory effect of merlin-1 on adhesion/metastasis and cytoskeleton remodeling in gastric cancer cells under hypoxia. Shijie Huaren Xiaohua Zazhi 2014; 22:3185-3193. [DOI: 10.11569/wcjd.v22.i22.3185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the regulatory effect of merlin-1 on cell proliferation, adhesion/metastasis and cytoskeleton remodeling in gastric cancer cells under hypoxia from Qinghai Han-, Hui- and Tibetan-ethnic patients, and to study if the function of merlin-1 in different ethnic groups is related to ethnic specificity under normoxic or hypoxic conditions.
METHODS: MTT assay was used to analyze the influence of merlin-1 on the cell proliferation, adhesion/metastasis and motility, and immunofluorescence staining was performed to detect cytoskeleton remodeling, morphological changes, and the distribution of microvilli on the surface of gastric cancer cells from Han-, Hui- and Tibetan-ethnic patients. In addition, we explored whether the function of merlin-1 in different ethnic groups is correlated with ethnic specificity under normoxic or hypoxic conditions.
RESULTS: The proliferation of gastric cancer cells from Han-, Hui- and Tibetan-ethnic groups was inhibited by merlin-1 under both normoxic and conditions (Pnormoxic = 0.00, 0.00, 0.00; Phypoxic = 0.00, 0.00, 0.00), and the influence of merlin-1 on cancer cell proliferation was not related to ethnic specificity (Pnormoxic ≥ 0.05; Phypoxic ≥ 0.05). The results of adhesion/metastasis analysis showed that merlin-1 inhibited the adhesion/metastasis ability of gastric cancer cells from Han-, Hui- and Tibetan-ethnic groups under both normoxic and hypoxic conditions (Pnormoxic = 0.00, 0.00, 0.00; Phypoxic = 0.00, 0.00, 0.00), and the inhibitory effect of merlin-1 in three ethnic groups showed no significant differences [Pnormoxic = 0.51 (3 h), 0.07 (48 h); Phypoxic = 0.47 (3 h), 0.17 (48 h)]. By detection of cytoskeleton remodeling, morphological change and microvilli distribution, it was found that merlin-1 enhanced cytoskeleton remodeling under hypoxic conditions compared with normoxic conditions.
CONCLUSION: Merlin-1 can inhibit the proliferation and adhesion/metastasis of gastric cancer cells under both hypoxic and normoxic conditions, which is independent on the ethnicity of patients from whom gastric cancer cells are obtained. However, merlin-1 enhances cytoskeleton remodeling under hypoxic conditions.
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Schulz A, Zoch A, Morrison H. A neuronal function of the tumor suppressor protein merlin. Acta Neuropathol Commun 2014; 2:82. [PMID: 25012216 PMCID: PMC4149232 DOI: 10.1186/s40478-014-0082-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 06/30/2014] [Indexed: 02/07/2023] Open
Abstract
Mutagenic loss of the NF2 tumor suppressor gene encoded protein merlin is known to provoke the hereditary neoplasia syndrome, Neurofibromatosis type 2 (NF2). In addition to glial cell-derived tumors in the PNS and CNS, disease-related lesions also affect the skin and the eyes. Furthermore, 60% of NF2 patients suffer from peripheral nerve damage, clinically referred to as peripheral neuropathy. Strikingly, NF2-associated neuropathy often occurs in the absence of nerve damaging tumors, suggesting tumor-independent events. Recent findings indicate an important role of merlin in neuronal cell types concerning neuromorphogenesis, axon structure maintenance and communication between axons and Schwann cells. In this review, we compile clinical and experimental evidences for the underestimated role of the tumor suppressor merlin in the neuronal compartment.
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Hong L, Sklar LA. Targeting GTPases in Parkinson's disease: comparison to the historic path of kinase drug discovery and perspectives. Front Mol Neurosci 2014; 7:52. [PMID: 24926233 PMCID: PMC4046578 DOI: 10.3389/fnmol.2014.00052] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/18/2014] [Indexed: 11/21/2022] Open
Abstract
Neurological diseases have placed heavy social and financial burdens on modern society. As the life expectancy of humans is extended, neurological diseases, such as Parkinson’s disease, have become increasingly common among senior populations. Although the enigmas of Parkinson’s diseases await resolution, more vivid pictures on the cause, progression, and control of the illness are emerging after years of research. On the molecular level, GTPases are implicated in the etiology of Parkinson’s disease and are rational pharmaceutical targets for their control. However, targeting individual GTPases, which belong to a superfamily of proteins containing multiple members with a conserved guanine nucleotide binding domain, has proven to be challenging. In contrast, pharmaceutical pursuit of inhibition of kinases, which constitute another superfamily of proteins with more than 500 members, has been fairly successful. We reviewed the breakthroughs in the history of kinase drug discovery to provide guidance for the GTPase field. We summarize recent progress made in the regulation of GTPase activity. We also present an efficient and cost effective approach to drug screening, which uses multiplex flow cytometry and mixture-based positional scanning libraries. These methods allow simultaneous measurements of both the activity and the selectivity of the screened library. Several GTPase activator clusters were identified which showed selectivity against different GTPase subfamilies. While the clusters need to be further deconvoluted to identify individual active compounds, the method described here and the structure information gathered create a foundation for further developments to build upon.
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Affiliation(s)
- Lin Hong
- Department of Pathology, The University of New Mexico Albuquerque, NM, USA ; Center for Molecular Discovery, The University of New Mexico Albuquerque, NM, USA
| | - Larry A Sklar
- Department of Pathology, The University of New Mexico Albuquerque, NM, USA ; Center for Molecular Discovery, The University of New Mexico Albuquerque, NM, USA ; Cancer Center, The University of New Mexico Albuquerque, NM, USA
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Schulz A, Walther C, Morrison H, Bauer R. In vivo electrophysiological measurements on mouse sciatic nerves. J Vis Exp 2014. [PMID: 24747166 DOI: 10.3791/51181] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Electrophysiological studies allow a rational classification of various neuromuscular diseases and are of help, together with neuropathological techniques, in the understanding of the underlying pathophysiology(1). Here we describe a method to perform electrophysiological studies on mouse sciatic nerves in vivo. The animals are anesthetized with isoflurane in order to ensure analgesia for the tested mice and undisturbed working environment during the measurements that take about 30 min/animal. A constant body temperature of 37 °C is maintained by a heating plate and continuously measured by a rectal thermo probe(2). Additionally, an electrocardiogram (ECG) is routinely recorded during the measurements in order to continuously monitor the physiological state of the investigated animals. Electrophysiological recordings are performed on the sciatic nerve, the largest nerve of the peripheral nervous system (PNS), supplying the mouse hind limb with both motoric and sensory fiber tracts. In our protocol, sciatic nerves remain in situ and therefore do not have to be extracted or exposed, allowing measurements without any adverse nerve irritations along with actual recordings. Using appropriate needle electrodes(3) we perform both proximal and distal nerve stimulations, registering the transmitted potentials with sensing electrodes at gastrocnemius muscles. After data processing, reliable and highly consistent values for the nerve conduction velocity (NCV) and the compound motor action potential (CMAP), the key parameters for quantification of gross peripheral nerve functioning, can be achieved.
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Affiliation(s)
| | | | - Helen Morrison
- Leibniz Institute for Age Research, Fritz Lipmann Institute
| | - Reinhard Bauer
- Institute of Molecular Cell Biology & Center for Sepsis Control and Care (CSCC) Jena University Hospital, Friedrich Schiller University Jena;
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Gavilan HS, Kulikauskas RM, Gutmann DH, Fehon RG. In vivo functional analysis of the human NF2 tumor suppressor gene in Drosophila. PLoS One 2014; 9:e90853. [PMID: 24595234 PMCID: PMC3942481 DOI: 10.1371/journal.pone.0090853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 02/04/2014] [Indexed: 11/19/2022] Open
Abstract
The proper control of tissue growth is essential during normal development and an important problem in human disease. Merlin, the product of the Neurofibromatosis 2 tumor suppressor gene, has been extensively studied to understand its functions in growth control. Here we describe experiments in which we used Drosophila as an in vivo system to test the functions of the normal human NF2 gene products and patient-derived mutant alleles. Although the predominant NF2 gene isoform, isoform 1, could functionally replace the Drosophila Merlin gene, a second isoform with a distinct C-terminal tail could not. Immunofluorescence studies show that the two isoforms have distinct subcellular localizations when expressed in the polarized imaginal epithelium, and function in genetic rescue assays correlates with apical localization of the NF2 protein. Interestingly, we found that a patient-derived missense allele, NF2L64P, appears to be temperature sensitive. These studies highlight the utility of Drosophila for in vivo functional analysis of highly conserved human disease genes.
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Affiliation(s)
- Heather S. Gavilan
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Rima M. Kulikauskas
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - David H. Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Richard G. Fehon
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Widemann BC, Acosta MT, Ammoun S, Belzberg AJ, Bernards A, Blakeley J, Bretscher A, Cichowski K, Clapp DW, Dombi E, Evans GD, Ferner R, Fernandez-Valle C, Fisher MJ, Giovannini M, Gutmann DH, Hanemann CO, Hennigan R, Huson S, Ingram D, Kissil J, Korf BR, Legius E, Packer RJ, McClatchey AI, McCormick F, North K, Pehrsson M, Plotkin SR, Ramesh V, Ratner N, Schirmer S, Sherman L, Schorry E, Stevenson D, Stewart DR, Ullrich N, Bakker AC, Morrison H. CTF meeting 2012: Translation of the basic understanding of the biology and genetics of NF1, NF2, and schwannomatosis toward the development of effective therapies. Am J Med Genet A 2014; 164A:563-78. [PMID: 24443315 DOI: 10.1002/ajmg.a.36312] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 07/17/2013] [Indexed: 12/28/2022]
Abstract
The neurofibromatoses (NF) are autosomal dominant genetic disorders that encompass the rare diseases NF1, NF2, and schwannomatosis. The NFs affect more people worldwide than Duchenne muscular dystrophy and Huntington's disease combined. NF1 and NF2 are caused by mutations of known tumor suppressor genes (NF1 and NF2, respectively). For schwannomatosis, although mutations in SMARCB1 were identified in a subpopulation of schwannomatosis patients, additional causative gene mutations are still to be discovered. Individuals with NF1 may demonstrate manifestations in multiple organ systems, including tumors of the nervous system, learning disabilities, and physical disfigurement. NF2 ultimately can cause deafness, cranial nerve deficits, and additional severe morbidities caused by tumors of the nervous system. Unmanageable pain is a key finding in patients with schwannomatosis. Although today there is no marketed treatment for NF-related tumors, a significant number of clinical trials have become available. In addition, significant preclinical efforts have led to a more rational selection of potential drug candidates for NF trials. An important element in fueling this progress is the sharing of knowledge. For over 20 years the Children's Tumor Foundation has convened an annual NF Conference, bringing together NF professionals to share novel findings, ideas, and build collaborations. The 2012 NF Conference held in New Orleans hosted over 350 NF researchers and clinicians. This article provides a synthesis of the highlights presented at the conference and as such, is a "state-of-the-field" for NF research in 2012.
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Affiliation(s)
- Brigitte C Widemann
- Pediatric Oncology Branch, NIH-National Cancer Institute, Bethesda, Maryland
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Schulz A, Kyselyova A, Baader SL, Jung MJ, Zoch A, Mautner VF, Hagel C, Morrison H. Neuronal merlin influences ERBB2 receptor expression on Schwann cells through neuregulin 1 type III signalling. ACTA ACUST UNITED AC 2013; 137:420-32. [PMID: 24309211 PMCID: PMC3914471 DOI: 10.1093/brain/awt327] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Merlin mutations in Neurofibromatosis type 2 cause tumorigenic transformation of Schwann cells, leading to schwannoma development. Schulz et al. show that loss of neuronally expressed merlin alone increases the susceptibility of adjacent Schwann cells to mitogenic signals through the Neuregulin1-ErbB2/3 pathway. Axonal surface proteins encompass a group of heterogeneous molecules, which exert a variety of different functions in the highly interdependent relationship between axons and Schwann cells. We recently revealed that the tumour suppressor protein merlin, mutated in the hereditary tumour syndrome neurofibromatosis type 2, impacts significantly on axon structure maintenance in the peripheral nervous system. We now report on a role of neuronal merlin in the regulation of the axonal surface protein neuregulin 1 important for modulating Schwann cell differentiation and myelination. Specifically, neuregulin 1 type III expression is reduced in sciatic nerve tissue of neuron-specific knockout animals as well as in biopsies from seven patients with neurofibromatosis type 2. In vitro experiments performed on both the P19 neuronal cell line and primary dorsal root ganglion cells demonstrate the influence of merlin on neuregulin 1 type III expression. Moreover, expression of ERBB2, a Schwann cell receptor for neuregulin 1 ligands is increased in nerve tissue of both neuron-specific merlin knockout animals and patients with neurofibromatosis type 2, demonstrating for the first time that axonal merlin indirectly regulates Schwann cell behaviour. Collectively, we have identified that neuronally expressed merlin can influence Schwann cell activity in a cell-extrinsic manner.
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Affiliation(s)
- Alexander Schulz
- 1 Leibniz Institute for Age Research, Fritz Lipmann Institute, 07745 Jena, Germany
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DeGeer J, Lamarche-Vane N. Rho GTPases in neurodegeneration diseases. Exp Cell Res 2013; 319:2384-94. [PMID: 23830879 DOI: 10.1016/j.yexcr.2013.06.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
Abstract
Rho GTPases are molecular switches that modulate multiple intracellular signaling processes by means of various effector proteins. As a result, Rho GTPase activities are tightly spatiotemporally regulated in order to ensure homeostasis within the cell. Though the roles of Rho GTPases during neural development have been well documented, their participation during neurodegeneration has been far less characterized. Herein we discuss our current knowledge of the role and function of Rho GTPases and regulators during neurodegeneration, and highlight their potential as targets for therapeutic intervention in common neurodegenerative disorders.
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Affiliation(s)
- Jonathan DeGeer
- McGill University, Department of Anatomy and Cell Biology, Montreal, QC, Canada H3A 0C7
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