1
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Anerillas C, Perramon-Güell A, Altés G, Cuesta S, Vaquero M, Olomí A, Rodríguez-Barrueco R, Llobet-Navàs D, Egea J, Dolcet X, Yeramian A, Encinas M. Sprouty1 is a broad mediator of cellular senescence. Cell Death Dis 2024; 15:296. [PMID: 38670941 PMCID: PMC11053034 DOI: 10.1038/s41419-024-06689-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 04/12/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024]
Abstract
Genes of the Sprouty family (Spry1-4) restrain signaling by certain receptor tyrosine kinases. Consequently, these genes participate in several developmental processes and function as tumor suppressors in adult life. Despite these important roles, the biology of this family of genes still remains obscure. Here we show that Sprouty proteins are general mediators of cellular senescence. Induction of cellular senescence by several triggers in vitro correlates with upregulation of Sprouty protein levels. More importantly, overexpression of Sprouty genes is sufficient to cause premature cellular senescence, via a conserved N-terminal tyrosine (Tyrosine 53 of Sprouty1). Accordingly, fibroblasts from knockin animals lacking that tyrosine escape replicative senescence. In vivo, heterozygous knockin mice display delayed induction of cellular senescence during cutaneous wound healing and upon chemotherapy-induced cellular senescence. Unlike other functions of this family of genes, induction of cellular senescence appears to be independent of activation of the ERK1/2 pathway. Instead, we show that Sprouty proteins induce cellular senescence upstream of the p38 pathway in these in vitro and in vivo paradigms.
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Affiliation(s)
- Carlos Anerillas
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain.
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA.
- Homeostasis de tejidos y órganos program, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad Autónoma de Madrid, Madrid, Spain.
| | - Aida Perramon-Güell
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
| | - Gisela Altés
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
| | - Sara Cuesta
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
- Fundación de Investigación Biomédica de Cádiz, Hospital Universitario Puerta del Mar, Novena Planta, Investigación, Av Ana de Viya, 21, Cádiz, Spain
| | - Marta Vaquero
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
- Hospital Universitari Arnau de Vilanova, Rovira Roure, 80, Lleida, Spain
| | - Anna Olomí
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
| | - Ruth Rodríguez-Barrueco
- Laboratory of Precision Medicine, Oncobell Program. Bellvitge Biomedical Research Institute (IDIBELL), Gran via De l'Hospitalet, Barcelona, Spain
| | - David Llobet-Navàs
- Laboratory of Precision Medicine, Oncobell Program. Bellvitge Biomedical Research Institute (IDIBELL), Gran via De l'Hospitalet, Barcelona, Spain
| | - Joaquim Egea
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
| | - Xavi Dolcet
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
| | - Andrée Yeramian
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain
| | - Mario Encinas
- Developmental and Oncogenic Signaling Group, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Rovira Roure, 80, Lleida, Spain.
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2
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Kiyota N, Namekata K, Nishijima E, Guo X, Kimura A, Harada C, Nakazawa T, Harada T. Effects of constitutively active K-Ras on axon regeneration after optic nerve injury. Neurosci Lett 2023; 799:137124. [PMID: 36780941 DOI: 10.1016/j.neulet.2023.137124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/24/2023] [Accepted: 02/09/2023] [Indexed: 02/13/2023]
Abstract
Visual disturbance after optic nerve injury is a serious problem. Attempts have been made to enhance the intrinsic ability of retinal ganglion cells (RGCs) to regenerate their axons, and the importance of PI3K/Akt and RAF/MEK/ERK signal activation has been suggested. Since these signals are shared with oncogenic signaling cascades, in this study, we focused on a constitutively active form of K-Ras, K-RasV12, to determine if overexpression of this molecule could stimulate axon regeneration. We confirmed that K-RasV12 phosphorylated Akt and ERK in vitro. Intravitreal delivery of AAV2-K-RasV12 increased the number of surviving RGCs and promoted 1.0 mm of axon regeneration one week after optic nerve injury without inducing abnormal proliferative effects in the RGCs. In addition, AAV2-K-RasV12 induced robust RGC axon regeneration, reaching as far as approximately 2.5 mm from the injury site, in eight weeks. Our findings suggest that AAV2-K-RasV12 could provide a good model for speedy and efficient analysis of the mechanism underlying axon regeneration in vivo.
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Affiliation(s)
- Naoki Kiyota
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Euido Nishijima
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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3
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Arumugam S, Mincheva-Tasheva S, Periyakaruppiah A, de la Fuente S, Soler RM, Garcera A. Regulation of Survival Motor Neuron Protein by the Nuclear Factor-Kappa B Pathway in Mouse Spinal Cord Motoneurons. Mol Neurobiol 2017; 55:5019-5030. [PMID: 28808928 DOI: 10.1007/s12035-017-0710-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/02/2017] [Indexed: 12/20/2022]
Abstract
Survival motor neuron (SMN) protein deficiency causes the genetic neuromuscular disorder spinal muscular atrophy (SMA), characterized by spinal cord motoneuron degeneration. Since SMN protein level is critical to disease onset and severity, analysis of the mechanisms involved in SMN stability is one of the central goals of SMA research. Here, we describe the role of several members of the NF-κB pathway in regulating SMN in motoneurons. NF-κB is one of the main regulators of motoneuron survival and pharmacological inhibition of NF-κB pathway activity also induces mouse survival motor neuron (Smn) protein decrease. Using a lentiviral-based shRNA approach to reduce the expression of several members of NF-κB pathway, we observed that IKK and RelA knockdown caused Smn reduction in mouse-cultured motoneurons whereas IKK or RelB knockdown did not. Moreover, isolated motoneurons obtained from the severe SMA mouse model showed reduced protein levels of several NF-κB members and RelA phosphorylation. We describe the alteration of NF-κB pathway in SMA cells. In the context of recent studies suggesting regulation of altered intracellular pathways as a future pharmacological treatment of SMA, we propose the NF-κB pathway as a candidate in this new therapeutic approach.
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Affiliation(s)
- Saravanan Arumugam
- Unitat de Senyalització Neuronal, Dep. Medicina Experimental, Universitat de Lleida-IRBLLEIDA, Rovira Roure 80, 25198, Lleida, Spain
| | - Stefka Mincheva-Tasheva
- Unitat de Senyalització Neuronal, Dep. Medicina Experimental, Universitat de Lleida-IRBLLEIDA, Rovira Roure 80, 25198, Lleida, Spain
| | - Ambika Periyakaruppiah
- Unitat de Senyalització Neuronal, Dep. Medicina Experimental, Universitat de Lleida-IRBLLEIDA, Rovira Roure 80, 25198, Lleida, Spain
| | - Sandra de la Fuente
- Unitat de Senyalització Neuronal, Dep. Medicina Experimental, Universitat de Lleida-IRBLLEIDA, Rovira Roure 80, 25198, Lleida, Spain
| | - Rosa M Soler
- Unitat de Senyalització Neuronal, Dep. Medicina Experimental, Universitat de Lleida-IRBLLEIDA, Rovira Roure 80, 25198, Lleida, Spain.
| | - Ana Garcera
- Unitat de Senyalització Neuronal, Dep. Medicina Experimental, Universitat de Lleida-IRBLLEIDA, Rovira Roure 80, 25198, Lleida, Spain
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4
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Nozhat Z, Hedayati M, Pourhassan H. Signaling pathways in medullary thyroid carcinoma: therapeutic implications. INTERNATIONAL JOURNAL OF ENDOCRINE ONCOLOGY 2016. [DOI: 10.2217/ije-2016-0014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Medullary thyroid cancer (MTC) is the third most frequent thyroid cancer arising from thyroid parafollicular cells. Surgery is the first-line strategy in treatment of MTC but disease relapse and patient's death have been observed in approximately two out of three of MTC cases. Identification of molecular mechanisms and different signaling pathways has offered new insights for disease treatment. The development of tyrosine kinase inhibitors targeting these pathways has provided a promising landscape for prevention of progression in patients with advanced metastatic MTC. In this review article different altered molecular pathways implicated in the development of MTC and the therapeutic strategies based on targeting the identified signaling pathways have been summarized.
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Affiliation(s)
- Zahra Nozhat
- Cellular & Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Biotechnology Department, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Hedayati
- Cellular & Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hoda Pourhassan
- Clinical Instructor Faculty, School of Medicine, University of California Riverside, Riverside, CA 92521, USA
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5
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Zhong J. RAS and downstream RAF-MEK and PI3K-AKT signaling in neuronal development, function and dysfunction. Biol Chem 2016; 397:215-22. [PMID: 26760308 DOI: 10.1515/hsz-2015-0270] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/04/2016] [Indexed: 12/12/2022]
Abstract
In postmitotic neurons, the activation of RAS family small GTPases regulates survival, growth and differentiation. Dysregulation of RAS or its major effector pathway, the cascade of RAF-, mitogen-activated and extracellular-signal regulated kinase kinases (MEK), and extracellular-signal regulated kinases (ERK) causes the RASopathies, a group of neurodevelopmental disorders whose pathogenic mechanisms are the subject of intense research. I here summarize the functions of RAS-RAF-MEK-ERK signaling in neurons in vivo, and discuss perspectives for harnessing this pathway to enable novel treatments for nervous system injury, the RASopathies, and possibly other neurological conditions.
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6
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7-dehydrocholesterol efficiently supports Ret signaling in a mouse model of Smith-Opitz-Lemli syndrome. Sci Rep 2016; 6:28534. [PMID: 27334845 PMCID: PMC4917867 DOI: 10.1038/srep28534] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 06/06/2016] [Indexed: 11/09/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a rare disorder of cholesterol synthesis. Affected individuals exhibit growth failure, intellectual disability and a broad spectrum of developmental malformations. Among them, renal agenesis or hypoplasia, decreased innervation of the gut, and ptosis are consistent with impaired Ret signaling. Ret is a receptor tyrosine kinase that achieves full activity when recruited to lipid rafts. Mice mutant for Ret are born with no kidneys and enteric neurons, and display sympathetic nervous system defects causing ptosis. Since cholesterol is a critical component of lipid rafts, here we tested the hypothesis of whether the cause of the above malformations found in SLOS is defective Ret signaling owing to improper lipid raft composition or function. No defects consistent with decreased Ret signaling were found in newborn Dhcr7−/− mice, or in Dhcr7−/− mice lacking one copy of Ret. Although kidneys from Dhcr7−/− mice showed a mild branching defect in vitro, GDNF was able to support survival and downstream signaling of sympathetic neurons. Consistently, GFRα1 correctly partitioned to lipid rafts in brain tissue. Finally, replacement experiments demonstrated that 7-DHC efficiently supports Ret signaling in vitro. Taken together, our findings do not support a role of Ret signaling in the pathogenesis of SLOS.
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7
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Kramer ER, Liss B. GDNF-Ret signaling in midbrain dopaminergic neurons and its implication for Parkinson disease. FEBS Lett 2015; 589:3760-72. [DOI: 10.1016/j.febslet.2015.11.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/29/2015] [Accepted: 11/03/2015] [Indexed: 12/11/2022]
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8
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Cabrera JR, Viejo-Borbolla A, Martinez-Martín N, Blanco S, Wandosell F, Alcamí A. Secreted herpes simplex virus-2 glycoprotein G modifies NGF-TrkA signaling to attract free nerve endings to the site of infection. PLoS Pathog 2015; 11:e1004571. [PMID: 25611061 PMCID: PMC4303327 DOI: 10.1371/journal.ppat.1004571] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 11/12/2014] [Indexed: 12/26/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) and HSV-2 are highly prevalent viruses that cause a variety of diseases, from cold sores to encephalitis. Both viruses establish latency in peripheral neurons but the molecular mechanisms facilitating the infection of neurons are not fully understood. Using surface plasmon resonance and crosslinking assays, we show that glycoprotein G (gG) from HSV-2, known to modulate immune mediators (chemokines), also interacts with neurotrophic factors, with high affinity. In our experimental model, HSV-2 secreted gG (SgG2) increases nerve growth factor (NGF)-dependent axonal growth of sympathetic neurons ex vivo, and modifies tropomyosin related kinase (Trk)A-mediated signaling. SgG2 alters TrkA recruitment to lipid rafts and decreases TrkA internalization. We could show, with microfluidic devices, that SgG2 reduced NGF-induced TrkA retrograde transport. In vivo, both HSV-2 infection and SgG2 expression in mouse hindpaw epidermis enhance axonal growth modifying the termination zone of the NGF-dependent peptidergic free nerve endings. This constitutes, to our knowledge, the discovery of the first viral protein that modulates neurotrophins, an activity that may facilitate HSV-2 infection of neurons. This dual function of the chemokine-binding protein SgG2 uncovers a novel strategy developed by HSV-2 to modulate factors from both the immune and nervous systems.
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Affiliation(s)
- Jorge Rubén Cabrera
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas—Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigaciones Biologicas en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Abel Viejo-Borbolla
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas—Universidad Autónoma de Madrid, Madrid, Spain
| | - Nadia Martinez-Martín
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas—Universidad Autónoma de Madrid, Madrid, Spain
| | - Soledad Blanco
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas—Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisco Wandosell
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas—Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigaciones Biologicas en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Antonio Alcamí
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas—Universidad Autónoma de Madrid, Madrid, Spain
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9
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Sprouty1 induces a senescence-associated secretory phenotype by regulating NFκB activity: implications for tumorigenesis. Cell Death Differ 2013; 21:333-43. [PMID: 24270409 DOI: 10.1038/cdd.2013.161] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/02/2013] [Accepted: 10/09/2013] [Indexed: 12/11/2022] Open
Abstract
Genes of the Sprouty family (Spry1-4) are feedback inhibitors of receptor tyrosine kinase (RTK) signaling. As such, they restrain proliferation of many cell types and have been proposed as tumor-suppressor genes. Although their most widely accepted target is the Extracellular-regulated kinases (ERK) pathway, the mechanisms by which Spry proteins inhibit RTK signaling are poorly understood. In the present work, we describe a novel mechanism by which Spry1 restricts proliferation, independently of the ERK pathway. In vivo analysis of thyroid glands from Spry1 knockout mice reveals that Spry1 induces a senescence-associated secretory phenotype via activation of the NFκB pathway. Consistently, thyroids from Spry1 knockout mice are bigger and exhibit decreased markers of senescence including Ki67 labeling and senescence-associated β-galactosidase. Although such 'escape' from senescence is not sufficient to promote thyroid tumorigenesis in adult mice up to 5 months, the onset of Phosphatase and tensin homolog (Pten)-induced tumor formation is accelerated when Spry1 is concomitantly eliminated. Accordingly, we observe a reduction of SPRY1 levels in human thyroid malignancies when compared with non-tumoral tissue. We propose that Spry1 acts as a sensor of mitogenic activity that not only attenuates RTK signaling but also induces a cellular senescence response to avoid uncontrolled proliferation.
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10
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Protein tyrosine phosphatase receptor type O inhibits trigeminal axon growth and branching by repressing TrkB and Ret signaling. J Neurosci 2013; 33:5399-410. [PMID: 23516305 DOI: 10.1523/jneurosci.4707-12.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Axonal branches of the trigeminal ganglion (TG) display characteristic growth and arborization patterns during development. Subsets of TG neurons express different receptors for growth factors, but these are unlikely to explain the unique patterns of axonal arborizations. Intrinsic modulators may restrict or enhance cellular responses to specific ligands and thereby contribute to the development of axon growth patterns. Protein tyrosine phosphatase receptor type O (PTPRO), which is required for Eph receptor-dependent retinotectal development in chick and for development of subsets of trunk sensory neurons in mouse, may be such an intrinsic modulator of TG neuron development. PTPRO is expressed mainly in TrkB-expressing (TrkB(+)) and Ret(+) mechanoreceptors within the TG during embryogenesis. In PTPRO mutant mice, subsets of TG neurons grow longer and more elaborate axonal branches. Cultured PTPRO(-/-) TG neurons display enhanced axonal outgrowth and branching in response to BDNF and GDNF compared with control neurons, indicating that PTPRO negatively controls the activity of BDNF/TrkB and GDNF/Ret signaling. Mouse PTPRO fails to regulate Eph signaling in retinocollicular development and in hindlimb motor axon guidance, suggesting that chick and mouse PTPRO have different substrate specificities. PTPRO has evolved to fine tune growth factor signaling in a cell-type-specific manner and to thereby increase the diversity of signaling output of a limited number of receptor tyrosine kinases to control the branch morphology of developing sensory neurons. The regulation of Eph receptor-mediated developmental processes by protein tyrosine phosphatases has diverged between chick and mouse.
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11
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Chatterjee R, Ramos E, Hoffman M, VanWinkle J, Martin DR, Davis TK, Hoshi M, Hmiel SP, Beck A, Hruska K, Coplen D, Liapis H, Mitra R, Druley T, Austin P, Jain S. Traditional and targeted exome sequencing reveals common, rare and novel functional deleterious variants in RET-signaling complex in a cohort of living US patients with urinary tract malformations. Hum Genet 2012; 131:1725-38. [PMID: 22729463 PMCID: PMC3551468 DOI: 10.1007/s00439-012-1181-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 05/15/2012] [Indexed: 12/12/2022]
Abstract
Signaling by the glial cell line-derived neurotrophic factor (GDNF)-RET receptor tyrosine kinase and SPRY1, a RET repressor, is essential for early urinary tract development. Individual or a combination of GDNF, RET and SPRY1 mutant alleles in mice cause renal malformations reminiscent of congenital anomalies of the kidney or urinary tract (CAKUT) in humans and distinct from renal agenesis phenotype in complete GDNF or RET-null mice. We sequenced GDNF, SPRY1 and RET in 122 unrelated living CAKUT patients to discover deleterious mutations that cause CAKUT. Novel or rare deleterious mutations in GDNF or RET were found in six unrelated patients. A family with duplicated collecting system had a novel mutation, RET-R831Q, which showed markedly decreased GDNF-dependent MAPK activity. Two patients with RET-G691S polymorphism harbored additional rare non-synonymous variants GDNF-R93W and RET-R982C. The patient with double RET-G691S/R982C genotype had multiple defects including renal dysplasia, megaureters and cryptorchidism. Presence of both mutations was necessary to affect RET activity. Targeted whole-exome and next-generation sequencing revealed a novel deleterious mutation G443D in GFRα1, the co-receptor for RET, in this patient. Pedigree analysis indicated that the GFRα1 mutation was inherited from the unaffected mother and the RET mutations from the unaffected father. Our studies indicate that 5% of living CAKUT patients harbor deleterious rare variants or novel mutations in GDNF-GFRα1-RET pathway. We provide evidence for the coexistence of deleterious rare and common variants in genes in the same pathway as a cause of CAKUT and discovered novel phenotypes associated with the RET pathway.
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Affiliation(s)
- Rajshekhar Chatterjee
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Enrique Ramos
- Department of Genetics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Mary Hoffman
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Jessica VanWinkle
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Daniel R Martin
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Thomas K Davis
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Masato Hoshi
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Stanley P Hmiel
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Anne Beck
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Keith Hruska
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Doug Coplen
- Department of Surgery (Urology), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Helen Liapis
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Robi Mitra
- Department of Genetics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Todd Druley
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Paul Austin
- Department of Surgery (Urology), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Sanjay Jain
- Department of Internal Medicine (Renal division), Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
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12
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Macià A, Gallel P, Vaquero M, Gou-Fabregas M, Santacana M, Maliszewska A, Robledo M, Gardiner JR, Basson MA, Matias-Guiu X, Encinas M. Sprouty1 is a candidate tumor-suppressor gene in medullary thyroid carcinoma. Oncogene 2012; 31:3961-72. [PMID: 22158037 PMCID: PMC3378485 DOI: 10.1038/onc.2011.556] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 10/07/2011] [Accepted: 10/31/2011] [Indexed: 12/30/2022]
Abstract
Medullary thyroid carcinoma (MTC) is a malignancy derived from the calcitonin-producing C-cells of the thyroid gland. Oncogenic mutations of the Ret proto-oncogene are found in all heritable forms of MTC and roughly one half of the sporadic cases. However, several lines of evidence argue for the existence of additional genetic lesions necessary for the development of MTC. Sprouty (Spry) family of genes is composed of four members in mammals (Spry1-4). Some Spry family members have been proposed as candidate tumor-suppressor genes in a variety of cancerous pathologies. In this work, we show that targeted deletion of Spry1 causes C-cell hyperplasia, a precancerous lesion preceding MTC, in young adult mice. Expression of Spry1 restrains proliferation of the MTC-derived cell line, TT. Finally, we found that the Spry1 promoter is frequently methylated in MTC and that Spry1 expression is consequently decreased. These findings identify Spry1 as a candidate tumor-suppressor gene in MTC.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Carcinoma, Medullary/genetics
- Carcinoma, Medullary/pathology
- Carcinoma, Neuroendocrine
- Cell Line, Tumor
- Cell Proliferation
- DNA Methylation
- Female
- Genes, Tumor Suppressor
- Humans
- Hyperplasia
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mice, Knockout
- Mice, SCID
- Phosphoproteins/genetics
- Phosphoproteins/metabolism
- Precancerous Conditions/pathology
- Promoter Regions, Genetic
- Proto-Oncogene Mas
- Proto-Oncogene Proteins c-ret/genetics
- RNA Interference
- RNA, Small Interfering
- Sequence Deletion
- Thyroid Gland/metabolism
- Thyroid Gland/pathology
- Thyroid Neoplasms/genetics
- Thyroid Neoplasms/pathology
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Affiliation(s)
- Anna Macià
- Department of Experimental Medicine, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
| | - Pilar Gallel
- Department of Pathology and Molecular Genetics, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
| | - Marta Vaquero
- Department of Experimental Medicine, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
| | - Myriam Gou-Fabregas
- Department of Experimental Medicine, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
| | - Maria Santacana
- Department of Pathology and Molecular Genetics, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
| | - Agnieszka Maliszewska
- Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Mercedes Robledo
- Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | | | - M. Albert Basson
- Department of Craniofacial Development, King’s College London, UK
| | - Xavier Matias-Guiu
- Department of Pathology and Molecular Genetics, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
| | - Mario Encinas
- Department of Experimental Medicine, Universitat de Lleida/Institut de Recerca Biomèdica de Lleida, Lleida, Spain
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13
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Synergistic growth inhibition of cancer cells harboring the RET/PTC1 oncogene by staurosporine and rotenone involves enhanced cell death. J Biosci 2011; 36:639-48. [DOI: 10.1007/s12038-011-9100-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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14
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The canonical nuclear factor-κB pathway regulates cell survival in a developmental model of spinal cord motoneurons. J Neurosci 2011; 31:6493-503. [PMID: 21525290 DOI: 10.1523/jneurosci.0206-11.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In vivo and in vitro motoneuron survival depends on the support of neurotrophic factors. These factors activate signaling pathways related to cell survival or inactivate proteins involved in neuronal death. In the present work, we analyzed the involvement of the nuclear factor-κB (NF-κB) pathway in mediating mouse spinal cord motoneuron survival promoted by neurotrophic factors. This pathway comprises ubiquitously expressed transcription factors that could be activated by two different routes: the canonical pathway, associated with IKKα/IKKβ kinase phosphorylation and nuclear translocation RelA (p65)/p50 transcription factors; and the noncanonical pathway, related to IKKα kinase homodimer phosphorylation and RelB/p52 transcription factor activation. In our system, we show that neurotrophic factors treatment induced IKKα and IKKβ phosphorylation and RelA nuclear translocation, suggesting NF-κB pathway activation. Protein levels of different members of the canonical or noncanonical pathways were reduced in a primary culture of isolated embryonic motoneurons using an interference RNA approach. Even in the presence of neurotrophic factors, selective reduction of IKKα, IKKβ, or RelA proteins induced cell death. In contrast, RelB protein reduction did not have a negative effect on motoneuron survival. Together these results demonstrated that the canonical NF-κB pathway mediates motoneuron survival induced by neurotrophic factors, and the noncanonical pathway is not related to this survival effect. Canonical NF-κB blockade induced an increase of Bim protein level and apoptotic cell death. Bcl-x(L) overexpression or Bax reduction counteracted this apoptotic effect. Finally, RelA knockdown causes changes of CREB and Smn protein levels.
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15
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Ryu H, Jeon GS, Cashman NR, Kowall NW, Lee J. Differential expression of c-Ret in motor neurons versus non-neuronal cells is linked to the pathogenesis of ALS. J Transl Med 2011; 91:342-52. [PMID: 21283077 PMCID: PMC3085919 DOI: 10.1038/labinvest.2010.203] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder characterized by selective degeneration of motor neurons throughout the central nervous systems. Non-cell autonomous damage induced by glial cells is linked to the selective susceptibility of motor neurons in ALS, but the mechanisms underlying this phenomenon are not known. We found that the expression of non-phosphorylated and phosphorylated forms (tyrosine (Tyr) residue 905, 1016, and 1062) of c-Ret, a member of the glial cell line-derived neurotrophic factor (GDNF) receptor, are altered in motor neurons of the lumbar spinal cord in ALS transgenic (G93A) mice and ALS (G93A) cell line models. Phosphorylated forms of c-Ret were colocalized with neurofilament aggregates in motor neurons of ALS mice. Consistent with the in vivo data, levels of non-phosphorylated and phosphorylated c-Ret (Tyr 905, 1016, and 1062) were decreased by oxidative stress in motor neuronal cells (NSC-34). Non-phosphorylated and phosphorylated forms of c-Ret immunoreactivity were markedly elevated in active microglia of ALS mice. Our findings suggest that constitutive oxidative stress modulates c-Ret function, thereby reducing GDNF signaling in motor neurons. Furthermore, the induction of c-Ret expression in microglia may contribute to non-cell autonomous cell death of motor neurons by available GDNF in ALS.
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Affiliation(s)
- Hoon Ryu
- Department of Neurology and Pathology, Boston University School of Medicine, VA Boston Healthcare System, Boston, MA 02130, USA.
| | - Gye Sun Jeon
- WCU Neurocytomics Group, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 113, Republic of Korea
| | - Neil R. Cashman
- Department of Medicine (Neurology) and Brain Research Centre, University of British Columbia Hospital, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, Canada V6T 2B5
| | - Neil W. Kowall
- VA Boston Healthcare System, Boston, MA 02130, USA,Department of Neurology and Pathology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Junghee Lee
- VA Boston Healthcare System, Boston, MA 02130, USA,Department of Neurology and Pathology, Boston University School of Medicine, Boston, MA 02118, USA,To whom correspondence should be addressed: Hoon Ryu, Ph.D. and Junghee Lee, Ph.D., VA Boston Healthcare System, Building 1A, Rm 105, Boston, MA 02130, USA, Tel: 857-364-6034, Fax: 857-364-4540, and
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16
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Cabrera JR, Bouzas-Rodriguez J, Tauszig-Delamasure S, Mehlen P. RET modulates cell adhesion via its cleavage by caspase in sympathetic neurons. J Biol Chem 2011; 286:14628-38. [PMID: 21357690 DOI: 10.1074/jbc.m110.195461] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RET is a tyrosine kinase receptor involved in numerous cellular mechanisms including proliferation, neuronal navigation, migration, and differentiation upon binding with glial cell derived neurotrophic factor family ligands. RET is an atypical tyrosine kinase receptor containing four cadherin domains in its extracellular part. Furthermore, it has been shown to act as a dependence receptor. Such a receptor is active in the absence of ligand, triggering apoptosis through a mechanism that requires receptor intracellular caspase cleavage. However, different data suggest that RET is not always associated with the cell death/survival balance but rather provides positional information. We demonstrate here that caspase cleavage of RET is involved in the regulation of adhesion in sympathetic neurons. The cleavage of RET generates an N-terminal truncated fragment that functions as a cadherin accessory protein, modifying cadherin environment and potentiating cadherin-mediated cell aggregation. Thus, the caspase cleavage of RET generates two RET fragments: one intracellular domain that can trigger cell death in apoptotic permissive settings, and one membrane-anchored ectodomain with cadherin accessory activity. We propose that this latter function may notably be important for the adequate development of the superior cervical ganglion.
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Affiliation(s)
- Jorge R Cabrera
- Apoptosis, Cancer, and Development Laboratory, Equipe labellisée La Ligue, Centre de Cancérologie de Lyon, INSERM U1052, CNRS UMR586, Université de Lyon, 69008 Lyon, France
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17
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The Gata3 transcription factor is required for the survival of embryonic and adult sympathetic neurons. J Neurosci 2010; 30:10833-43. [PMID: 20702712 DOI: 10.1523/jneurosci.0175-10.2010] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The transcription factor Gata3 is essential for the development of sympathetic neurons and adrenal chromaffin cells. As Gata3 expression is maintained up to the adult stage, we addressed its function in differentiated sympathoadrenal cells at embryonic and adult stages by conditional Gata3 elimination. Inactivation of Gata3 in embryonic DBH-expressing neurons elicits a strong reduction in neuron numbers due to apoptotic cell death and reduced proliferation. No selective effect on noradrenergic gene expression (TH and DBH) was observed. Interestingly, Gata3 elimination in DBH-expressing neurons of adult animals also results in a virtually complete loss of sympathetic neurons. In the Gata3-deficient population, the expression of anti-apoptotic genes (Bcl-2, Bcl-xL, and NFkappaB) is diminished, whereas the expression of pro-apoptotic genes (Bik, Bok, and Bmf) was increased. The expression of noradrenergic genes (TH and DBH) is not affected. These results demonstrate that Gata3 is continuously required for maintaining survival but not differentiation in the sympathetic neuron lineage up to mature neurons of adult animals.
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18
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Aron L, Klein P, Pham TT, Kramer ER, Wurst W, Klein R. Pro-survival role for Parkinson's associated gene DJ-1 revealed in trophically impaired dopaminergic neurons. PLoS Biol 2010; 8:e1000349. [PMID: 20386724 PMCID: PMC2850379 DOI: 10.1371/journal.pbio.1000349] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 02/24/2010] [Indexed: 12/16/2022] Open
Abstract
A mouse genetic study reveals a novel cell-survival role for the Parkinson's disease-associated gene DJ-1 in dopaminergic neurons that have reduced support from endogenous survival factors. The mechanisms underlying the selective death of substantia nigra (SN) neurons in Parkinson disease (PD) remain elusive. While inactivation of DJ-1, an oxidative stress suppressor, causes PD, animal models lacking DJ-1 show no overt dopaminergic (DA) neuron degeneration in the SN. Here, we show that aging mice lacking DJ-1 and the GDNF-receptor Ret in the DA system display an accelerated loss of SN cell bodies, but not axons, compared to mice that only lack Ret signaling. The survival requirement for DJ-1 is specific for the GIRK2-positive subpopulation in the SN which projects exclusively to the striatum and is more vulnerable in PD. Using Drosophila genetics, we show that constitutively active Ret and associated Ras/ERK, but not PI3K/Akt, signaling components interact genetically with DJ-1. Double loss-of-function experiments indicate that DJ-1 interacts with ERK signaling to control eye and wing development. Our study uncovers a conserved interaction between DJ-1 and Ret-mediated signaling and a novel cell survival role for DJ-1 in the mouse. A better understanding of the molecular connections between trophic signaling, cellular stress and aging could uncover new targets for drug development in PD. The major pathological event in Parkinson disease is the loss of dopaminergic neurons in a midbrain structure, the substantia nigra. The study of familial Parkinson disease has uncovered several disease-associated genes, including DJ-1. Subsequent studies have suggested that the DJ-1 protein is a suppressor of oxidative stress that might modify signaling pathways that regulate cell survival. However, because animal models lacking DJ-1 function do not show dopaminergic neurodegeneration, the function(s) of DJ-1 in vivo remain unclear. Using mouse genetics, we found that DJ-1 is required for survival of neurons of the substantia nigra only in aging conditions and only in neurons that are partially impaired in receiving trophic signals. Aging mice that lack DJ-1 and Ret, a receptor for a neuronal survival factor, lose more dopaminergic neurons in the substantia nigra as compared with aging mice that lack only Ret. Using the fruit fly Drosophila, we determined that DJ-1 interacts with constitutively active Ret and with its associated downstream signaling pathways. Therefore, understanding the molecular connections between trophic signaling, cellular stress and aging could facilitate the identification of new targets for drug development in Parkinson Disease.
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Affiliation(s)
- Liviu Aron
- Department of Molecular Neurobiology, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Pontus Klein
- Department of Molecular Neurobiology, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Thu-Trang Pham
- Helmholtz Center Munich, Technical University of Munich, National Center for Dementia Research, Neuherberg, Germany
| | | | - Wolfgang Wurst
- Helmholtz Center Munich, Technical University of Munich, National Center for Dementia Research, Neuherberg, Germany
| | - Rüdiger Klein
- Department of Molecular Neurobiology, Max Planck Institute of Neurobiology, Martinsried, Germany
- * E-mail:
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19
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Jain S, Knoten A, Hoshi M, Wang H, Vohra B, Heuckeroth RO, Milbrandt J. Organotypic specificity of key RET adaptor-docking sites in the pathogenesis of neurocristopathies and renal malformations in mice. J Clin Invest 2010; 120:778-90. [PMID: 20160347 DOI: 10.1172/jci41619] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 01/06/2010] [Indexed: 01/01/2023] Open
Abstract
The receptor tyrosine kinase ret protooncogene (RET) is implicated in the pathogenesis of several diseases and in several developmental defects, particularly those in neural crest-derived structures and the genitourinary system. In order to further elucidate RET-mediated mechanisms that contribute to these diseases and decipher the basis for specificity in the pleiotropic effects of RET, we characterized development of the enteric and autonomic nervous systems in mice expressing RET9 or RET51 isoforms harboring mutations in tyrosine residues that act as docking sites for the adaptors Plcgamma, Src, Shc, and Grb2. Using this approach, we found that development of the genitourinary system and the enteric and autonomic nervous systems is dependent on distinct RET-stimulated signaling pathways. Thus, mutation of RET51 at Y1062, a docking site for multiple adaptor proteins including Shc, caused distal colon aganglionosis reminiscent of Hirschsprung disease (HSCR). On the other hand, this mutation in RET9, which encodes an isoform that lacks the Grb2 docking site present in RET51, produced severe abnormalities in multiple organs. Mutations that abrogate RET-Plcgamma binding, previously shown to produce features reminiscent of congenital anomalies of kidneys or urinary tract (CAKUT) syndrome, produced only minor abnormalities in the nervous system. Abrogating RET51-Src binding produced no major defects in these systems. These studies provide insight into the basis of organotypic specificity and redundancy in RET signaling within these unique systems and in diseases such as HSCR and CAKUT.
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Affiliation(s)
- Sanjay Jain
- Department of Internal Medicine (Renal Division), Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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20
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Burke RE. Intracellular signalling pathways in dopamine cell death and axonal degeneration. PROGRESS IN BRAIN RESEARCH 2010; 183:79-97. [PMID: 20696316 PMCID: PMC3088517 DOI: 10.1016/s0079-6123(10)83005-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The pathways of programmed cell death (PCD) are now understood in extraordinary detail at the molecular level. Although much evidence suggests that they are likely to play a role in Parkinson's disease (PD), the precise nature of that role remains unknown. Two pathways of cell death that are especially well characterized are cyclin-dependent kinase 5-mediated phosphorylation of myocyte enhancer factor 2 and the mitogen-activated protein kinase signalling cascade. Although blockade of these pathways in animals has achieved a truly remarkable degree of neuroprotection of the neuron cell soma, it has not achieved protection of axons. Thus, there is a need to explore beyond the canonical pathways of PCD and investigate mechanisms of axon destruction. We also need to move beyond the narrow classic concept that the mechanisms of PCD are activated exclusively 'downstream', following cellular injury. Studies in the genetics of PD suggest that in some forms of the disease, activation may be an early 'upstream' event. Additionally, recent observations suggest that cell death in some contexts may not be initiated by injury, but instead by a failure of intrinsic cell survival signalling. These new points of view offer new opportunities for molecular targeting.
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Affiliation(s)
- Robert E Burke
- Department of Neurology, Columbia University, New York, NY, USA.
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21
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Angiotensin II-induced activation of c-Ret signaling is critical in ureteric bud branching morphogenesis. Mech Dev 2009; 127:21-7. [PMID: 19961928 DOI: 10.1016/j.mod.2009.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 11/16/2009] [Accepted: 11/27/2009] [Indexed: 12/27/2022]
Abstract
The renin-angiotensin system (RAS) plays a critical role in ureteric bud (UB) and kidney morphogenesis. Mutations in the genes encoding components of the RAS cause a spectrum of congenital abnormalities of the kidney and urinary tract (CAKUT). However, the mechanisms by which aberrations in the RAS result in CAKUT are poorly understood. Given that c-Ret receptor tyrosine kinase (RTK) is a major inducer of UB branching, the present study tested the hypothesis that angiotensin (Ang) II-induced activation of c-Ret plays a critical role in UB branching morphogenesis. E12.5 mice metanephroi were grown for 24h in the presence or absence of Ang II, Ang II AT(1) receptor (AT(1)R) antagonist candesartan, phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 or ERK1/2 inhibitor PD98059. Ang II increased the number of UB tips (61+/-2.4 vs. 45+/-4.3, p<0.05) compared with control. Quantitative RT-PCR analysis demonstrated that Ang II increased c-Ret mRNA levels in the kidney (1.35+/-0.05 vs. 1.0+/-0, p<0.01) and in the UB cells (1.28+/-0.04 vs. 1.0+/-0, p<0.01) compared to control. This was accompanied by increased Tyr(1062)Ret phosphorylation by Ang II (5.5+/-0.9 vs. 1.8+/-0.4 relative units, p<0.05). In addition, treatment of UB cells with Ang II (10(-5)M) increased phosphorylation of Akt compared to control (213+/-16 vs. 100+/-20%, p<0.05). In contrast, treatment of metanephroi or UB cells with candesartan decreased c-Ret mRNA levels (0.72+/-0.06 vs. 1.0+/-0, p<0.01; 0.68+/-0.07 vs. 1.0+/-0, p<0.05, respectively) compared with control. Ang II-induced UB branching was abrogated by LY294002 (24+/-2.6 vs. 37+/-3.0, p<0.05) or PD98059 (33+/-2.0 vs. 48+/-2.2, p<0.01). These data demonstrate that Ang II-induced UB branching depends on activation of Akt and ERK1/2. We conclude that cross-talk between the RAS and c-Ret signaling plays an important role in the development of the renal collecting system.
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Abstract
The RET (rearranged during transfection) protooncogene encodes a single pass transmembrane receptor that is expressed in cells derived from the neural crest and the urogenital tract. As part of a cell-surface complex, RET binds glial derived neurotrophic factor (GDNF) ligands in conjunction with GDNF-family alpha co-receptors (GFRalpha). Ligand-induced activation induces dimerization and tyrosine phosphorylation of the RET receptor with downstream activation of several signal transduction pathways. Activating germline RET mutations play a central role in the development of the multiple endocrine neoplasia (MEN) syndromes MEN2A, MEN2B, and familial medullary thyroid carcinoma (FMTC) and also in the development of the congenital abnormality Hirschsprung's disease. Approximately 50% of patients with sporadic MTC have somatic RET mutations, and a significant portion of papillary thyroid carcinomas result from chromosomal inversions or translocations, which activate RET (RET/PTC oncogenes). The RET protooncogene has a significant place in cancer prevention and treatment. Timely thyroidectomy in kindred members who have inherited a mutated RET allele, characteristic of MEN2A, MEN2B, or FMTC, can prevent MTC, the most common cause of death in these syndromes. Also, recently developed molecular therapeutics that target the RET pathway have shown activity in clinical trials of patients with advanced MTC, a disease for which there has been no effective therapy.
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Affiliation(s)
- Samuel A Wells
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Andressoo JO, Saarma M. Signalling mechanisms underlying development and maintenance of dopamine neurons. Curr Opin Neurobiol 2009; 18:297-306. [PMID: 18678254 DOI: 10.1016/j.conb.2008.07.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 07/08/2008] [Accepted: 07/09/2008] [Indexed: 12/23/2022]
Abstract
Majority of the brain dopamine (DA) neurons reside in a distinct area in the midbrain and project axons into the striatum and frontal cortex to control central nervous system (CNS) functions such as movement, motivation and mood. Age-associated specific loss of DA neurons particularly in the midbrain region substantia nigra pars compacta (SNpc) causes Parkinson disease (PD), an incurable condition characterized by rigidity, involuntary and slowed movement affecting about 1% of people over the age of 60 years. Dopamine neurons appear to be one of the most sensitive types of neurons to both intrinsic and extrinsic stressors in the brain. Here we summarize how transcription factors, growth factors and in particular neurotrophic factors are used to make and maintain DA neurons. We also discuss mechanisms that underlie their specific vulnerability and highlight current state of art in drug development.
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Affiliation(s)
- Jaan-Olle Andressoo
- Institute of Biotechnology, Viikki Biocenter, University of Helsinki, Viikinkaari 9, P.O. Box 56, FIN-00014 Helsinki, Finland
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Rozen EJ, Schmidt H, Dolcet X, Basson MA, Jain S, Encinas M. Loss of Sprouty1 rescues renal agenesis caused by Ret mutation. J Am Soc Nephrol 2008; 20:255-9. [PMID: 19056869 DOI: 10.1681/asn.2008030267] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Renal morphogenesis requires a balance between positive and negative signals, which are provided in part by the receptor tyrosine kinase Ret and the putative tumor suppressor Sprouty1, respectively. Tyrosine 1062 of Ret is a binding site for several adaptor and effector proteins, such as Grb2/Sos/Ras, which activate the ERK pathway. Mice lacking Ret tyrosine 1062 nearly mimic the phenotype of Ret-knockout mice, which includes renal agenesis. Sprouty1 regulates Ret activity by modulating the ERK pathway, but the mechanism by which this occurs is uncertain. Here, we show that loss of Sprouty1 rescues the renal agenesis and early postnatal lethality caused by lack of Ret tyrosine 1062. The kidneys and lower urinary tracts of double-mutant mice developed normally. This effect was specific to the urinary system, because loss of Sprouty1 did not rescue the defects in the enteric nervous system characteristic of animals lacking Ret tyrosine 1062. These results suggest that Sprouty1 can modulate ERK signaling downstream of Ret, independent of Grb2/Sos/Ras, during renal morphogenesis.
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Affiliation(s)
- Esteban J Rozen
- Cell Signaling and Apoptosis Group, Institut de Recerca Biomedica de Lleida, Lleida, Spain
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