1
|
Tao ZY, Yang WF, Zhu WY, Wang LL, Li KY, Guan XY, Su YX. A neural-related gene risk score for head and neck squamous cell carcinoma. Oral Dis 2024; 30:477-491. [PMID: 36346196 DOI: 10.1111/odi.14434] [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: 07/18/2022] [Revised: 10/27/2022] [Accepted: 11/05/2022] [Indexed: 11/10/2022]
Abstract
OBJECTIVES This study aimed to establish a neural-related gene risk score (NRGRS) for the prediction of head and neck squamous cell carcinoma prognosis and explore its predictive value on the benefit of immune checkpoint inhibitor therapy. METHODS Based on the transcriptome data of HNSCC patients (n = 546) from The Cancer Genome Atlas database, 37 neural-related hub genes were identified by weighted gene co-expression network analysis. Four genes (ITGA5, PYGM, GNG7 and ATP2A3) were identified to construct NRGRS using Lasso-Cox regression method based on the derivation cohort and validated in the Gene Expression Omnibus cohort (n = 109). The survival analysis was performed to validate the prognostic value of NRGRS and immune characteristics in NRGRS-defined subgroups were analyzed. RESULTS NRGRS-high patients had a worse overall survival than NRGRS-low patients. Tumors with high NRGRS were more likely to have high infiltration of naive CD4+ T cells, M0, M2 macrophages and resting mast cells, which illustrated suppressive immunity and less benefit from immunotherapy therapy. CONCLUSION NRGRS strongly correlates with survival and is a promising biomarker to predict immunotherapy benefits for head and neck cancer patients. This study provides evidence for the potential correlation between neural-related transcriptome alteration and immune activity.
Collapse
Affiliation(s)
- Zhuo-Ying Tao
- Division of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| | - Wei-Fa Yang
- Division of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| | - Wang-Yong Zhu
- Division of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| | - Lei-Lei Wang
- Division of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| | - Kar Yan Li
- Clinical Research Centre, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| | - Xin-Yuan Guan
- Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Yu-Xiong Su
- Division of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| |
Collapse
|
2
|
Fard D, Testa E, Panzeri V, Rizzolio S, Bianchetti G, Napolitano V, Masciarelli S, Fazi F, Maulucci G, Scicchitano BM, Sette C, Viscomi MT, Tamagnone L. SEMA6C: a novel adhesion-independent FAK and YAP activator, required for cancer cell viability and growth. Cell Mol Life Sci 2023; 80:111. [PMID: 37002363 PMCID: PMC10066115 DOI: 10.1007/s00018-023-04756-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/22/2023] [Accepted: 03/11/2023] [Indexed: 04/03/2023]
Abstract
Transmembrane semaphorins are signaling molecules, controlling axonal wiring and embryo development, which are increasingly implicated in human diseases. Semaphorin 6C (Sema6C) is a poorly understood family member and its functional role is still unclear. Upon targeting Sema6C expression in a range of cancer cells, we observed dramatic growth suppression, decreased ERK phosphorylation, upregulation of cell cycle inhibitor proteins p21, p27 and p53, and the onset of cell senescence, associated with activation of autophagy. These data are consistent with a fundamental requirement for Sema6C to support viability and growth in cancer cells. Mechanistically, we unveiled a novel signaling pathway elicited by Sema6C, and dependent on its intracellular domain, mediated by tyrosine kinases c-Abl and Focal Adhesion Kinase (FAK). Sema6C was found in complex with c-Abl, and induced its phosphorylation, which in turn led to FAK activation, independent of cell-matrix adhesion. Sema6C-induced FAK activity was furthermore responsible for increased nuclear localization of YAP transcriptional regulator. Moreover, Sema6C conferred YAP signaling-dependent long-term cancer cell survival upon nutrient deprivation. In conclusion, our findings demonstrate that Sema6C elicits a cancer promoting-signaling pathway sustaining cell viability and self-renewal, independent of growth factors and nutrients availability.
Collapse
Affiliation(s)
- Damon Fard
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Erika Testa
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Valentina Panzeri
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Giada Bianchetti
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Virginia Napolitano
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Silvia Masciarelli
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy
- Department of Anatomical, Histological, Forensic and Orthopaedic Sciences, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Francesco Fazi
- Department of Anatomical, Histological, Forensic and Orthopaedic Sciences, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Giuseppe Maulucci
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Gemelli-IRCCS, Rome, Italy
| | - Bianca Maria Scicchitano
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Gemelli-IRCCS, Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Gemelli-IRCCS, Rome, Italy
| | - Maria Teresa Viscomi
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Gemelli-IRCCS, Rome, Italy
| | - Luca Tamagnone
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy.
- Fondazione Policlinico Gemelli-IRCCS, Rome, Italy.
| |
Collapse
|
3
|
Semaphorin 6C Suppresses Proliferation of Pancreatic Cancer Cells via Inhibition of the AKT/GSK3/β-Catenin/Cyclin D1 Pathway. Int J Mol Sci 2022; 23:ijms23052608. [PMID: 35269749 PMCID: PMC8910270 DOI: 10.3390/ijms23052608] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 02/01/2023] Open
Abstract
Semaphorins (SEMAs) are axon guidance factors that participate in axonal connections and nerve system development. However, the functional roles of SEMAs in tumorigenesis are still largely uncovered. By using in silico data analysis, we found that SEMA6C was downregulated in pancreatic cancer, and its reduction was correlated with worse survival rates. RNA sequencing revealed that cell cycle-related genes, especially cyclin D1, were significantly altered after blockage of SEMA6C by neutralizing antibodies or ectopic expressions of SEMA6C. Mechanistic investigation demonstrated that SEMA6C acts as a tumor suppressor in pancreatic cancer by inhibiting the AKT/GSK3 signaling axis, resulting in a decrease in cyclin D1 expression and cellular proliferation. The enhancement of cyclin D1 expression and cyclin-dependent kinase activation in SEMA6C-low cancer created a druggable target of CDK4/6 inhibitors. We also elucidated the mechanism underlying SEMA6C downregulation in pancreatic cancer and demonstrated a novel regulatory role of miR-124-3p in suppressing SEMA6C. This study provides new insights of SEMA6C-mediated anti-cancer action and suggests the treatment of SEMA6C-downregulated cancer by CDK4/6 inhibitors.
Collapse
|
4
|
Masuda T, Taniguchi M. Contribution of semaphorins to the formation of the peripheral nervous system in higher vertebrates. Cell Adh Migr 2016; 10:593-603. [PMID: 27715392 PMCID: PMC5160040 DOI: 10.1080/19336918.2016.1243644] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Semaphorins are a large family of proteins characterized by sema domains and play a key role not only in the formation of neural circuits, but in the immune system, angiogenesis, tumor progression, and bone metabolism. To date, 15 semaphorins have been reported to be involved in the formation of the peripheral nervous system (PNS) in higher vertebrates. A number of experiments have revealed their functions in the PNS, where they act mainly as axonal guidance cues (as repellents or attractants). Semaphorins also play an important role in the migration of neurons and formation of sensory-motor connections in the PNS. This review summarizes recent knowledge regarding the functions of higher vertebrate semaphorins in the formation of the PNS.
Collapse
Affiliation(s)
- Tomoyuki Masuda
- a Department of Neurobiology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan.,b Doctoral and Master's Programs in Kansei , Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba , Ibaraki , Japan
| | - Masahiko Taniguchi
- c Department of Cell Science , Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine , Hokkaido , Japan
| |
Collapse
|
5
|
Yan Y, Cui H, Guo C, Wei J, Huang Y, Li L, Qin Q. Singapore grouper iridovirus-encoded semaphorin homologue (SGIV-sema) contributes to viral replication, cytoskeleton reorganization and inhibition of cellular immune responses. J Gen Virol 2014; 95:1144-1155. [PMID: 24535211 DOI: 10.1099/vir.0.060608-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Semaphorins are a large, phylogenetically conserved family of proteins that are involved in a wide range of biological processes including axonal steering, organogenesis, neoplastic transformation, as well as immune responses. In this study, a novel semaphorin homologue gene belonging to the Singapore grouper iridovirus (SGIV), ORF155R (termed SGIV-sema), was cloned and characterized. The coding region of SGIV-sema is 1728 bp in length, encoding a predicted protein with 575 aa. SGIV-sema contains a ~370 aa N-terminal Sema domain, a conserved plexin-semaphorin-integrin (PSI) domain, and an immunoglobulin (Ig)-like domain near the C terminus. SGIV-sema is an early gene product during viral infection and predominantly distributed in the cytoplasm with a speckled and clubbed pattern of appearance. Functionally, SGIV-sema could promote viral replication during SGIV infection in vitro, with no effect on the proliferation of host cells. Intriguingly, ectopically expressed SGIV-sema could alter the cytoskeletal structure of fish cells, characterized by a circumferential ring of microtubules near the nucleus and a disrupted microfilament organization. Furthermore, SGIV-sema was able to attenuate the cellular immune response, as demonstrated by decreased expression of inflammation/immune-related genes such as IL-8, IL-15, TNF-α and mediator of IRF3 activation (MITA), in SGIV-sema-expressing cells before and after SGIV infection. Ultimately, our study identified a novel, functional SGIV gene that could regulate cytoskeletal structure, immune responses and facilitate viral replication.
Collapse
Affiliation(s)
- Yang Yan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Huachun Cui
- Department of Medicine, University of Alabama at Birmingham, 901 19th Street South, Birmingham, AL 35294, USA
| | - Chuanyu Guo
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, PR China
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Jingguang Wei
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Youhua Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Lili Li
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, PR China
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| | - Qiwei Qin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
| |
Collapse
|
6
|
Svensson A, Libelius R, Tågerud S. Semaphorin 6C expression in innervated and denervated skeletal muscle. J Mol Histol 2007; 39:5-13. [PMID: 17605078 DOI: 10.1007/s10735-007-9113-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 06/07/2007] [Indexed: 10/23/2022]
Abstract
Semaphorins are secreted or transmembrane proteins important for axonal guidance and for the structuring of neuronal systems. Semaphorin 6C, a transmembrane Semaphorin, has growth cone collapsing activity and is expressed in adult skeletal muscle. In the present study the expression of Semaphorin 6C mRNA and immunoreactivity has been compared in innervated and denervated mouse hind-limb and hemidiaphragm muscles. Microscopic localization of immunoreactivity was studied in innervated and denervated rat skeletal muscle. The results show that Semaphorin 6C mRNA expression and immunoreactivity on Western blots are down-regulated following denervation. The mRNA of Semaphorin 6C as well as immunoreactivity determined by Western blots are expressed in extrasynaptic as well as perisynaptic regions of muscle. Immunohistochemical studies, however, show Semaphorin 6C-like immunoreactivity to be concentrated at neuromuscular junctions. The results suggest a role for Semaphorin 6C in neuromuscular communication.
Collapse
Affiliation(s)
- Anna Svensson
- School of Pure and Applied Natural Sciences, University of Kalmar, Kalmar, 391 82, Sweden.
| | | | | |
Collapse
|
7
|
Mann F, Chauvet S, Rougon G. Semaphorins in development and adult brain: Implication for neurological diseases. Prog Neurobiol 2007; 82:57-79. [PMID: 17537564 DOI: 10.1016/j.pneurobio.2007.02.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 01/18/2007] [Accepted: 02/26/2007] [Indexed: 01/17/2023]
Abstract
As a group, Semaphorins are expressed in most tissues and this distribution varies considerably with age. Semaphorins are dynamically expressed during embryonic development and their expression is often associated with growing axons. This expression decreases with maturity and several observations support the idea that in adult brain the expression of secreted Semaphorins is sensitive to electrical activity and experience. The functional role of Semaphorins in guiding axonal projections is well established and more recent evidence points to additional roles in the development, function and reorganization of synaptic complexes. Semaphorins exert the majority of their effects by binding to cognate receptor proteins through their extracellular domains. A common theme is that Semaphorin-triggered signalling induces the rearrangement of the actin and microtubule cytoskeleton. Mutations in Semaphorin genes are linked to several human diseases associated with neurological changes, but their actual influence in the pathogenesis of these diseases remains to be demonstrated. In addition, Semaphorins and their receptors are likely to mediate cross-talk between neurons and other cell types, including in pathological situations where their influence can be damaging or favourable depending on the context. We discuss how the manipulation of Semaphorin function might be crucial for future clinical studies.
Collapse
Affiliation(s)
- Fanny Mann
- CNRS UMR 6216, Université de la Méditerranée, Developmental Biology Institute of Marseille Luminy, Case 907, Parc Scientifique de Luminy, 13288 Marseille Cedex 09, France
| | | | | |
Collapse
|
8
|
Burgaya F, Fontana X, Martínez A, Montolio M, Mingorance A, Simó S, del Río JA, Soriano E. Semaphorin 6C leads to GSK-3-dependent growth cone collapse and redistributes after entorhino-hippocampal axotomy. Mol Cell Neurosci 2006; 33:321-34. [PMID: 17029982 DOI: 10.1016/j.mcn.2006.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 07/24/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022] Open
Abstract
We studied the changes in the distribution of a specific variant of Semaphorin Y/6C (Sema6C) in mouse forebrain after axotomy of the entorhino-hippocampal perforant pathway. We found this isoform to be widely expressed during development, remaining in the adult and showing variations in distribution when the perforant pathway was axotomized. These changes were detected in both the hippocampal and entorhinal cortices. Sema6C1 immunoreactivity (IR) was high in the stratum radiatum of the hippocampus proper and the inner molecular layer of the dentate gyrus; the entorhinal cortex showed Sema6C1 IR in both cell bodies and in fibers of the II/III and V/VI layers. In axotomized animals, the IR of the ipsilateral, but not the contralateral, hemisphere showed that IR had moved into the stratum lacunosum-moleculare, the medial molecular layer of the dentate gyrus and the fibers, but not the cell bodies, of the entorhinal cortex. These results were not reproduced after lateral axotomy of the fimbria fornix, indicating a specific role for Sema6C variants in the generation and/or stability of entorhino-hippocampal synapses. Growth cone collapse of entorhinal and pyramidal neurons, as well as activation of glycogen synthase kinase-3 (GSK-3) through depletion of the inactive pool, induced by diffusible Sema6C1 further supports this view.
Collapse
Affiliation(s)
- Ferran Burgaya
- Institute for Research in Biomedicine (IRB) and Cell Biology Department, Faculty of Biology, University of Barcelona, Barcelona, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
Semaphorins are secreted, transmembrane, and GPI-linked proteins, defined by cysteine-rich semaphorin protein domains, that have important roles in a variety of tissues. Humans have 20 semaphorins, Drosophila has five, and two are known from DNA viruses; semaphorins are also found in nematodes and crustaceans but not in non-animals. They are grouped into eight classes on the basis of phylogenetic tree analyses and the presence of additional protein motifs. The expression of semaphorins has been described most fully in the nervous system, but they are also present in most, or perhaps all, other tissues. Functionally, semaphorins were initially characterized for their importance in the development of the nervous system and in axonal guidance. More recently, they have been found to be important for the formation and functioning of the cardiovascular, endocrine, gastrointestinal, hepatic, immune, musculoskeletal, renal, reproductive, and respiratory systems. A common theme in the mechanisms of semaphorin function is that they alter the cytoskeleton and the organization of actin filaments and the microtubule network. These effects occur primarily through binding of semaphorins to their receptors, although transmembrane semaphorins also serve as receptors themselves. The best characterized receptors for mediating semaphorin signaling are members of the neuropilin and plexin families of transmembrane proteins. Plexins, in particular, are thought to control many of the functional effects of semaphorins; the molecular mechanisms of semaphorin signaling are still poorly understood, however. Given the importance of semaphorins in a wide range of functions, including neural connectivity, angiogenesis, immunoregulation, and cancer, much remains to be learned about these proteins and their roles in pathology and human disease.
Collapse
Affiliation(s)
- Umar Yazdani
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R Terman
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
10
|
Chédotal A, Kerjan G, Moreau-Fauvarque C. The brain within the tumor: new roles for axon guidance molecules in cancers. Cell Death Differ 2005; 12:1044-56. [PMID: 16015381 DOI: 10.1038/sj.cdd.4401707] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Slits, semaphorins and netrins are three families of proteins that can attract or repel growing axons and migrating neurons in the developing nervous system of vertebrates and invertebrates. Recent studies have shown that they are widely expressed outside the nervous system and that they may play important roles in cancers. Several of the genes encoding these proteins are localized on chromosomal region associated with frequent loss-of-heterozygosity in tumors and cancer cell lines and there is also significant hypermethylation of their promoter suggesting that they may act as tumor suppressors. In addition, proteins in all these families and their receptors appear to control the vascularization of the tumors. Last, many axon guidance molecules also regulate cell migration and apoptosis in normal and tumorigenic tissues. Overall, this suggests that molecules that could mimick or block the activity of axon guidance molecules may be used as therapeutic agents for the treatment of malignancy.
Collapse
Affiliation(s)
- A Chédotal
- CNRS UMR7102, Equipe Développement Neuronal, Université Paris 6, Batiment B, Case 12, 9 Quai Saint-Bernard, 75005 Paris, France.
| | | | | |
Collapse
|
11
|
Kerjan G, Dolan J, Haumaitre C, Schneider-Maunoury S, Fujisawa H, Mitchell KJ, Chédotal A. The transmembrane semaphorin Sema6A controls cerebellar granule cell migration. Nat Neurosci 2005; 8:1516-24. [PMID: 16205717 DOI: 10.1038/nn1555] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Accepted: 08/31/2005] [Indexed: 11/08/2022]
Abstract
The transmembrane semaphorin protein Sema6A is broadly expressed in the developing nervous system. Sema6A repels several classes of developing axons in vitro and contributes to thalamocortical axon guidance in vivo. Here we show that during cerebellum development, Sema6A is selectively expressed by postmitotic granule cells during their tangential migration in the deep external granule cell layer, but not during their radial migration. In Sema6A-deficient mice, many granule cells remain ectopic in the molecular layer where they differentiate and are contacted by mossy fibers. The analysis of ectopic granule cell morphology in Sema6a-/- mice, and of granule cell migration and neurite outgrowth in cerebellar explants, suggests that Sema6A controls the initiation of granule cell radial migration, probably through a modulation of nuclear and/or soma translocation. Finally, the analysis of mouse chimeras suggests that this function of Sema6A is primarily non-cell-autonomous.
Collapse
Affiliation(s)
- Géraldine Kerjan
- Centre National de la Recherche Scientifique UMR7102, Université de Paris 6, Case 12, 9 Quai Saint-Bernard, 75005 Paris, France
| | | | | | | | | | | | | |
Collapse
|
12
|
Collet P, Domenjoud L, Devignes MD, Murad H, Schohn H, Dauça M. The human semaphorin 6B gene is down regulated by PPARs. Genomics 2005; 83:1141-50. [PMID: 15177567 DOI: 10.1016/j.ygeno.2004.01.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2003] [Accepted: 01/04/2004] [Indexed: 11/20/2022]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are ligand-inducible transcription factors and belong to the nuclear hormone receptor superfamily. They form heterodimers with the retinoid X receptor and bind to specific peroxisome proliferator-response elements. The latter are direct repeat elements of two hexanucleotides with the consensus sequence TG(A/T)CCT separated by a single nucleotide spacer. Such a sequence, or a similar one, has been found in numerous PPAR-inducible genes. We developed an affinity method to isolate human genomic fragments containing binding sites for PPARs and to identify novel PPAR target genes. For this, an antibody raised against all PPAR subtypes was used. Immunoselected fragments were amplified and sequenced and one of them, ISF5148, was found to bind specifically to PPARs in gel mobility shift, supershift, and competition assays and to exhibit a down transregulation potentiality in transfection experiments under clofibrate (a PPARalpha agonist) treatment. ISF5148 was mapped by BLAST analysis 8.5 kb upstream of the human semaphorin 6B [(HSA)SEMA6B] gene. The latter encodes a member of the semaphorin family of axon guidance molecules. Expression of this gene in human glioblastoma T98G cells was strongly down regulated after treatment with clofibrate or Wy-14,643, two PPARalpha agonists. Our study establishes for the first time that PPAR activators diminish the expression of the human (HSA)SEMA6B gene. These data are relevant to the fact that PPARs are implicated in brain development, neuronal differentiation, and lipid metabolism in the central nervous system. In addition, cross talk between the peroxisome proliferator and retinoic acid pathways is suggested.
Collapse
Affiliation(s)
- Philippe Collet
- EA 3446 "Peroxisome Proliferators," Faculty of Sciences, BP 239, University Henri Poincaré-Nancy 1, 54506 Vandoeuvre-les-Nancy, France.
| | | | | | | | | | | |
Collapse
|
13
|
Matsuda N, Mishina M. Identification of chaperonin CCT gamma subunit as a determinant of retinotectal development by whole-genome subtraction cloning from zebrafish no tectal neuron mutant. Development 2004; 131:1913-25. [PMID: 15056614 DOI: 10.1242/dev.01085] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Zebrafish no tectal neuron (ntn) mutant obtained by trimethylpsoralen (TMP) mutagenesis showed defects in tectal neuropil formation and small eyes. We carried out whole-genome subtraction between wild-type and mutant zebrafish embryos using the representational difference analysis (RDA) method. Nineteen subtraction products enabled us to construct genetic and physical maps of the ntn region. Direct selection of cDNAs using a YAC clone encompassing the ntn locus and RT-PCR analysis of transcripts identified a 143 bp deletion in the cct3 gene encoding the gamma subunit of chaperonin containing TCP-1 (CCT). Injection of antisense cct3 morpholino oligonucleotides into zebrafish embryos induced characteristic ntn phenotypes including defects in retinal ganglion cell (RGC) differentiation and tectal neuropil formation. Moreover, injection of cct3 mRNA successfully rescued ntn mutant embryos. Our results suggest that RDA is an efficient and widely applicable cloning strategy in zebrafish genetics. The strong expression of the cct3 mRNA started in the entire embryos by 12 hpf and was sustained thereafter, but there were no detectable abnormalities in body patterning and neurogenesis in ntn mutant embryos at 30 hpf. The expression patterns of transcription factor genes ath5 and brn3b that are essential for the development and maintenance of RGCs were indistinguishable between wild-type and ntn mutant embryos, but those of early and late differentiation markers of RGCs, nicotinic acetylcholine receptor beta 3 and zn5, were diminished in mutant embryos. Immunostaining of acetylated tubulin also revealed the impairment of RGC neurite extension. Thus, the ntn mutation of the cct3 gene impaired the differentiation of retinal neuroepithelial cells to RGCs. Similarly, the expression of brn3b was normal in the tectum of ntn mutants, but tectal neuropil formation was abolished. These results suggest that the gamma subunit of chaperonin CCT plays an essential role in retinotectal development.
Collapse
Affiliation(s)
- Naoto Matsuda
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, and SORST, Japan Science and Technology Agency, Tokyo 113-0033, Japan
| | | |
Collapse
|
14
|
Taniguchi M, Shimizu T. Characterization of a novel member of murine semaphorin family. Biochem Biophys Res Commun 2004; 314:242-8. [PMID: 14715272 DOI: 10.1016/j.bbrc.2003.12.083] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Semaphorin gene family contains a large number of secreted and transmembrane proteins, and some of them are functioning as the repulsive and attractive cues of the axon guidance during development. Here we report murine orthologues of a novel member of class 6 semaphorin gene, semaphorin 6D (Sema6D), mapped on the chromosome 2. Sema6D is mainly expressed in the brain and lung, and the ubiquitous expression in the brain continues from embryonic late stage to adulthood, as determined by Northern blot and in situ hybridization. We also found that Sema6D has five different splicing variants, and the expression patterns of individual isoforms differ depending on the tissues. Thus, Sema6D may play important roles in various functions including the axon guidance during development and neuronal plasticity.
Collapse
Affiliation(s)
- Masahiko Taniguchi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Japan.
| | | |
Collapse
|
15
|
Lillesaar C, Fried K. Neurites from trigeminal ganglion explants grown in vitro are repelled or attracted by tooth-related tissues depending on developmental stage. Neuroscience 2004; 125:149-61. [PMID: 15051154 DOI: 10.1016/j.neuroscience.2004.01.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2004] [Indexed: 11/25/2022]
Abstract
Although neurite attracting factors are present in the developing dental pulp and trigeminal ganglion (TG) axons can respond to such factors, nerve fibres do not enter the tooth pulp until a late developmental stage compared with surrounding tissues supplied by the TG. This suggests that the dental pulp secretes neurite growth inhibitory molecules. Semaphorins represent one group of substances, which can inhibit/repel growing neurites. The aims of the present study were to investigate if dental tissue explants inhibit/repel neurite growth from TGs at some developmental stages in vitro, and if so, to seek evidence for or against a participation of semaphorins in that interaction. By co-culturing mandibular or dental epithelial and mesenchymal tissue explants and TGs in collagen gels, we found that embryonic day 11 (E11) mandibular and E13 dental mesenchymal explants repel neurites from corresponding TGs. Repulsion was replaced by attraction if tissues from late embryonic or early postnatal mice (E17-postnatal day 5) were used. Using semi-quantitative reverse transcription/polymerase chain reaction we showed that a number of semaphorins were expressed by tooth-related mesenchyme collected from embryonic and postnatal mice. The expression of some semaphorins (3A, 3C, 3F, 4F, 5B, 6A, 6B and 6C) was high early in development and then decreased in a temporal pattern that correlated with neurite inhibitory/repulsive effects of dental mesenchyme observed in co-cultures. The expression of other semaphorins increased with development (3B, 4A and 7A), whilst others varied irregularly or remained at a fairly constant level (3E, 4B, 4C, 4D, 4G and 5A). Immunohistochemistry was used to determine if tooth-related nerve fibres possess neuropilins. This revealed that axons surrounding embryonic tooth buds express neuropilin-1, but not neuropilin-2. In postnatal teeth, nerve fibres located within the tooth pulp were immunonegative for neuropilin-1 and neuropilin-2. We conclude that developing mandibular/dental mesenchyme can inhibit/repel neurite growth in vitro. Our results support the hypothesis that semaphorins may be involved in this interaction.
Collapse
Affiliation(s)
- C Lillesaar
- Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden
| | | |
Collapse
|
16
|
Kikuchi K, Kishino A, Konishi O, Kumagai K, Hosotani N, Saji I, Nakayama C, Kimura T. In vitro and in vivo characterization of a novel semaphorin 3A inhibitor, SM-216289 or xanthofulvin. J Biol Chem 2003; 278:42985-91. [PMID: 12933805 DOI: 10.1074/jbc.m302395200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SM-216289 (xanthofulvin) isolated from the fermentation broth of a fungal strain, Penicillium sp. SPF-3059, was identified as a strong semaphorin 3A (Sema3A) inhibitor. Sema3A-induced growth cone collapse of dorsal root ganglion neurons in vitro was completely abolished in the presence of SM-216289 at levels less than 2 mum (IC50 = 0.16 mum). When dorsal root ganglion explants were co-cultured with Sema3A-producing COS7 cells in a collagen gel matrix, SM-216289 enabled neurites to grow toward the COS7 cells. SM-216289 diminished the binding of Sema3A to its receptor neuropilin-1 in vitro, suggesting a direct interference of receptor-ligand association. Moreover, our data suggest that SM-216289 interacted with Sema3A directly and blocked the binding of Sema3A to its receptor. We examined the efficacy of SM-216289 in vivo using a rat olfactory nerve axotomy model, in which strong Sema3A induction has been reported around regenerating axons. The regeneration of olfactory nerves was significantly accelerated by a local administration of SM-216289 in the lesion site, suggesting the involvement of Sema3A in neural regeneration as an inhibitory factor. SM-216289 is an excellent molecular probe to investigate the function of Sema3A, in vitro and in vivo, and may be useful for the treatment of traumatic neural injuries.
Collapse
Affiliation(s)
- Kaoru Kikuchi
- Research Division, Sumitomo Pharmaceuticals Co., Ltd., 3-1-98, Kasugade-naka, Konohana-ku, Osaka 554-0022, Japan
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Holtmaat AJGD, De Winter F, De Wit J, Gorter JA, da Silva FHL, Verhaagen J. Semaphorins: contributors to structural stability of hippocampal networks? PROGRESS IN BRAIN RESEARCH 2002; 138:17-38. [PMID: 12432760 DOI: 10.1016/s0079-6123(02)38068-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Anthony J G D Holtmaat
- Netherlands Institute for Brain Research, Meibergdreef 33, 1105 AZ Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
18
|
Qu X, Wei H, Zhai Y, Que H, Chen Q, Tang F, Wu Y, Xing G, Zhu Y, Liu S, Fan M, He F. Identification, characterization, and functional study of the two novel human members of the semaphorin gene family. J Biol Chem 2002; 277:35574-85. [PMID: 12110693 DOI: 10.1074/jbc.m206451200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We cloned two novel human transmembrane semaphorins, (HSA)SEMA6C and (HSA)SEMA6D, that belong to the class VI subgroup of the semaphorin family. The genes for SEMA6C and SEMA6D are mapped on chromosome 1q12-21.1 and 15q21.1, respectively. Among the adult tissues, SEMA6C is expressed only in skeletal muscle, whereas SEMA6D is expressed abundantly in kidney, brain, and placenta and moderately in the heart and skeletal muscles. During murine development, neither SEMA6C nor SEMA6D was expressed in embryonic day 10.5 (E10.5) embryos, but both were highly expressed in the areas of the lateral ventricle, the striatum, the wall of the midbrain, the pons/midbrain junction, and the choroid plexus of E13 embryos. Were neurons, neither axons nor astrocytes, highly expressed both semaphorins. Three isoforms of SEMA6C and five isoforms of SEMA6D derived from alternative splicing were identified, and their expression was regulated in a tissue- and development-dependent manner. Deletion analysis indicated that a sema domain and a PSI domain are integrally necessary for correct post-translation modification and subcellular localization. The extracellular domain of SEMA6C inhibited axonal extension of nerve growth factor-differentiated PC12 cells and induced the growth cone collapse of chicken dorsal root ganglion, rat hippocampal neurons, and rat cortical neurons in a dose-responsive manner. SEMA6D acted like SEMA6C except it had no significant effect on the growth cones of rat cortical neurons.
Collapse
Affiliation(s)
- Xianghu Qu
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese National Human Genome Center at Beijing
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Gesemann M, Litwack ED, Yee KT, Christen U, O'Leary DD. Identification of candidate genes for controlling development of the basilar pons by differential display PCR. Mol Cell Neurosci 2001; 18:1-12. [PMID: 11461149 DOI: 10.1006/mcne.2001.0996] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The basilar pons, a major hindbrain nucleus involved in sensory-motor integration, has become a model system for studying long-distance neuronal migration, axon-target recognition by collateral branching, and the formation of patterned axonal projections. To identify genes potentially involved in these developmental events, we have performed a differential display PCR screen comparing RNA isolated from the developing basilar pons with RNA obtained from developing cerebellum and olfactory bulb, as well as the mature basilar pons. Using 400 different combinations of primers, we screened more than 11,000 labeled DNA fragments and identified 201 that exhibited higher expression in the basilar pons than in the control tissues. From these, 138 distinct gene fragments were cloned. The differential expression of a large subset of these fragments was confirmed using RNase protection assays. In situ hybridization analysis revealed that the expression of many of these genes is limited to the basilar pons and only a few other brain regions, suggesting that they may play specific roles in pontine development.
Collapse
Affiliation(s)
- M Gesemann
- Molecular Neurobiology Laboratory, The Salk Institute, 10010 North Torrey Pines Road, San Diego, California 92037, USA
| | | | | | | | | |
Collapse
|
20
|
Correa RG, Sasahara RM, Bengtson MH, Katayama ML, Salim AC, Brentani MM, Sogayar MC, de Souza SJ, Simpson AJ. Human Semaphorin 6B [(HSA)SEMA6B], A Novel Human Class 6 Semaphorin Gene: Alternative Splicing and All-Trans-Retinoic Acid-Dependent Downregulation in Glioblastoma Cell Lines. Genomics 2001; 73:343-8. [PMID: 11350127 DOI: 10.1006/geno.2001.6525] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have identified a novel human gene related to the class 6 semaphorin family of axon guidance molecules, termed human semaphorin 6B or (HSA)SEMA6B. Two splicing variants of this gene were identified by RT-PCR: (HSA)SEMA6B.1 (short isoform) and (HSA)SEMA6B.2 (longer isoform). Computational analysis suggests that these isoforms correspond to putative secreted and transmembranous semaphorins, respectively. The levels of (HSA)SEMA6B expression were evaluated by Northern blot analysis in different tissues and in some pathological and pharmacological conditions. We observed that (HSA)SEMA6B is highly expressed in human brain and at lower levels in a variety of other tissues. Interestingly, the (HSA)SEMA6B transcript was downregulated in two different human glioblastoma cell lines (T98G and A172) upon prolonged treatment with all-trans-retinoic acid, an anti-tumor and differentiation-inducing agent.
Collapse
Affiliation(s)
- R G Correa
- Ludwig Institute for Cancer Research, Rua Prof. Antonio Prudente 109, 4 andar, São Paulo, SP, 01509-010, Brazil.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Delaire S, Billard C, Tordjman R, Chédotal A, Elhabazi A, Bensussan A, Boumsell L. Biological activity of soluble CD100. II. Soluble CD100, similarly to H-SemaIII, inhibits immune cell migration. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:4348-54. [PMID: 11254688 DOI: 10.4049/jimmunol.166.7.4348] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD100 is a human 150-kDa homodimer expressed at the surface of most hemopoietic cells, and its gene belongs to the Ig and semaphorin gene families. Semaphorin genes encode soluble and membrane-bound proteins, most of which have been shown to act as chemorepellents on growth cone guidance. CD100 is discrete, as it is a transmembrane leukocyte surface molecule that can also exist in a soluble form. While our previous studies using mAbs suggested that the transmembrane form of CD100 plays a role in lymphocyte activation, no function was shown for its soluble form. Here, we investigated the effect of soluble CD100 in a cell migration assay; both CD100 spontaneously shed from a stable transfectant and soluble recombinant CD100 inhibited spontaneous and chemokine-induced migration of human monocytes. Interestingly, only the dimeric form of CD100 exerted an effect. Moreover, soluble CD100 inhibited migration of cells from monocytic and B cell lineages. A similar inhibitory effect on migration was observed with H-SemaIII, but not H-SemaIV, semaphorins. In addition, both CD100 and H-SemaIII were recognized by two CD100 mAbs in an ELISA, and one of these mAb abolished the inhibitory effect of each of these semaphorins. We also provide evidence that CD100 and H-SemaIII act through the same receptor on immune cells, which is not neuropilin-1. Furthermore, we describe a function on immune cells for H-SemaIII, a semaphorin to date only studied in the nervous system.
Collapse
Affiliation(s)
- S Delaire
- Institut National de la Santé et de la Recherche Médicale, Unité 448, Faculté de Médecine, Créteil, France
| | | | | | | | | | | | | |
Collapse
|
22
|
Leighton PA, Mitchell KJ, Goodrich LV, Lu X, Pinson K, Scherz P, Skarnes WC, Tessier-Lavigne M. Defining brain wiring patterns and mechanisms through gene trapping in mice. Nature 2001; 410:174-9. [PMID: 11242070 DOI: 10.1038/35065539] [Citation(s) in RCA: 326] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The search to understand the mechanisms regulating brain wiring has relied on biochemical purification approaches in vertebrates and genetic approaches in invertebrates to identify molecular cues and receptors for axon guidance. Here we describe a phenotype-based gene-trap screen in mice designed for the large-scale identification of genes controlling the formation of the trillions of connections in the mammalian brain. The method incorporates an axonal marker, which helps to identify cell-autonomous mechanisms in axon guidance, and has generated a resource of mouse lines with striking patterns of axonal labelling, which facilitates analysis of the normal wiring diagram of the brain. Studies of two of these mouse lines have identified an in vivo guidance function for a vertebrate transmembrane semaphorin, Sema6A, and have helped re-evaluate that of the Eph receptor EphA4.
Collapse
Affiliation(s)
- P A Leighton
- Howard Hughes Medical Institute and Department of Anatomy, University of California, San Francisco, California 94143-0452, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Yu HH, Huang AS, Kolodkin AL. Semaphorin-1a acts in concert with the cell adhesion molecules fasciclin II and connectin to regulate axon fasciculation in Drosophila. Genetics 2000; 156:723-31. [PMID: 11014819 PMCID: PMC1461270 DOI: 10.1093/genetics/156.2.723] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Semaphorins comprise a large family of phylogenetically conserved secreted and transmembrane glycoproteins, many of which have been implicated in repulsive axon guidance events. The transmembrane semaphorin Sema-1a in Drosophila is expressed on motor axons and is required for the generation of neuromuscular connectivity. Sema-1a can function as an axonal repellent and mediates motor axon defasciculation. Here, by manipulating the levels of Sema-1a and the cell adhesion molecules fasciclin II (Fas II) and connectin (Conn) on motor axons, we provide further evidence that Sema-1a mediates axonal defasciculation events by acting as an axonally localized repellent and that correct motor axon guidance results from a balance between attractive and repulsive guidance cues expressed on motor neurons.
Collapse
Affiliation(s)
- H H Yu
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | |
Collapse
|
24
|
Abstract
Semaphorin 6A (Sema6A) (previously named Semaphorin VIa) is the originally described member of the vertebrate semaphorin class 6, a group of transmembrane semaphorins homologous to the insect semaphorin class 1. Although Sema-1a (previously named semaphorin I) has been implicated in axon guidance in insects, the function of Sema6A is currently unknown. We have expressed the extracellular domain of Sema6A in mammalian cells as either a monomeric or a dimeric fusion protein and tested for potential axon guidance effects on two populations of embryonic neurons in growth cone collapse and collagen matrix chemorepulsion assays. Sema6A was observed to induce growth cone collapse of sympathetic neurons with an EC50 of approximately 200 pM, although a 10-fold higher (EC50 of approximately 2 nM) concentration was necessary to induce growth cone collapse of dorsal root ganglion neurons. The activity of Sema6A is likely to depend on protein dimerization or oligomerization. Although Sema6A mRNA is expressed in complex patterns during embryonic development, it is strikingly absent from sympathetic ganglia. Sema6A is, however, expressed in areas avoided by sympathetic axons and in areas innervated by sympathetics, but before their arrival. Our results demonstrate that transmembrane semaphorins, like the secreted ones, can act as repulsive axon guidance cues. Our findings are consistent with a role for Sema6A in channeling sympathetic axons into the sympathetic chains and controlling the temporal sequence of sympathetic target innervation.
Collapse
|
25
|
Goshima Y, Sasaki Y, Nakayama T, Ito T, Kimura T. Functions of semaphorins in axon guidance and neuronal regeneration. JAPANESE JOURNAL OF PHARMACOLOGY 2000; 82:273-9. [PMID: 10875745 DOI: 10.1254/jjp.82.273] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The semaphorin family comprises secreted and transmembrane signaling proteins that function in the nervous, immune, respiratory and cardiovascular systems. Sema3A, a secreted type of semaphorin, is now recognized as the most potent repulsive molecule inhibiting or repelling neurite outgrowth. The biological actions of Sema3A are mediated via neuropilin (Npn)-1, a receptor or one of the components of a receptor complex for Sema3A. Although the molecular mechanisms of Sema3A-Npn-1 signaling are largely unknown, a pertussis toxin-sensitive trimeric G protein(s), Rac-1, collapsin response mediator protein (CRMP), cyclic nucleotides and tyrosine kinase(s) have been implicated as essential and/or modulatory components of these processes. As repulsive molecules could be impediments to axon outgrowth, determining how these repulsive molecules exert their actions has the potential of uncovering new therapeutic approaches to injury and/or degeneration of neuronal tissues.
Collapse
Affiliation(s)
- Y Goshima
- Department of Pharmacology, Yokohama City University School of Medicine, Yokohama, Japan
| | | | | | | | | |
Collapse
|
26
|
Jackman A, Fitzgerald M. Development of peripheral hindlimb and central spinal cord innervation by subpopulations of dorsal root ganglion cells in the embryonic rat. J Comp Neurol 2000. [DOI: 10.1002/(sici)1096-9861(20000313)418:3<281::aid-cne4>3.0.co;2-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
27
|
Encinas JA, Kikuchi K, Chedotal A, de Castro F, Goodman CS, Kimura T. Cloning, expression, and genetic mapping of Sema W, a member of the semaphorin family. Proc Natl Acad Sci U S A 1999; 96:2491-6. [PMID: 10051670 PMCID: PMC26812 DOI: 10.1073/pnas.96.5.2491] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The semaphorins comprise a large family of membrane-bound and secreted proteins, some of which have been shown to function in axon guidance. We have cloned a transmembrane semaphorin, Sema W, that belongs to the class IV subgroup of the semaphorin family. The mouse and rat forms of Sema W show 97% amino acid sequence identity with each other, and each shows about 91% identity with the human form. The gene for Sema W is divided into 15 exons, up to 4 of which are absent in the human cDNAs that we sequenced. Unlike many other semaphorins, Sema W is expressed at low levels in the developing embryo but was found to be expressed at high levels in the adult central nervous system and lung. Functional studies with purified membrane fractions from COS7 cells transfected with a Sema W expression plasmid showed that Sema W has growth-cone collapse activity against retinal ganglion-cell axons, indicating that vertebrate transmembrane semaphorins, like secreted semaphorins, can collapse growth cones. Genetic mapping of human SEMAW with human/hamster radiation hybrids localized the gene to chromosome 2p13. Genetic mapping of mouse Semaw with mouse/hamster radiation hybrids localized the gene to chromosome 6, and physical mapping placed the gene on bacteria artificial chromosomes carrying microsatellite markers D6Mit70 and D6Mit189. This localization places Semaw within the locus for motor neuron degeneration 2, making it an attractive candidate gene for this disease.
Collapse
Affiliation(s)
- J A Encinas
- Sumitomo Pharmaceuticals Research Center, 3-1-98 Kasugade-Naka, Konohana, Osaka 554-0022, Japan
| | | | | | | | | | | |
Collapse
|