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Rouchka EC, de Almeida C, House RB, Daneshmand JC, Chariker JH, Saraswat-Ohri S, Gomes C, Sharp M, Shum-Siu A, Cesarz GM, Petruska JC, Magnuson DSK. Construction of a Searchable Database for Gene Expression Changes in Spinal Cord Injury Experiments. J Neurotrauma 2024; 41:1030-1043. [PMID: 37917105 DOI: 10.1089/neu.2023.0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Spinal cord injury (SCI) is a debilitating condition with an estimated 18,000 new cases annually in the United States. The field has accepted and adopted standardized databases such as the Open Data Commons for Spinal Cord Injury (ODC-SCI) to aid in broader analyses, but these currently lack high-throughput data despite the availability of nearly 6000 samples from over 90 studies available in the Sequence Read Archive. This limits the potential for large datasets to enhance our understanding of SCI-related mechanisms at the molecular and cellular level. Therefore, we have developed a protocol for processing RNA-Seq samples from high-throughput sequencing experiments related to SCI resulting in both raw and normalized data that can be efficiently mined for comparisons across studies, as well as homologous discovery across species. We have processed 1196 publicly available RNA-Seq samples from 50 bulk RNA-Seq studies across nine different species, resulting in an SQLite database that can be used by the SCI research community for further discovery. We provide both the database as well as a web-based front-end that can be used to query the database for genes of interest, differential gene expression, genes with high variance, and gene set enrichments.
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Affiliation(s)
- Eric C Rouchka
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky, USA
- Kentucky IDeA Networks of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, Kentucky, USA
- Bioinformatics Program, University of Louisville, Louisville, Kentucky, USA
| | - Carlos de Almeida
- Translational Neuroscience Program, University of Louisville, Louisville, Kentucky, USA
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Randi B House
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Bioengineering, University of Louisville, Louisville, Kentucky, USA
| | - Jonah C Daneshmand
- Bioinformatics Program, University of Louisville, Louisville, Kentucky, USA
| | - Julia H Chariker
- Kentucky IDeA Networks of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, Kentucky, USA
- Department of Neuroscience Training, University of Louisville, Louisville, Kentucky, USA
| | - Sujata Saraswat-Ohri
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
| | - Cynthia Gomes
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky, USA
| | - Morgan Sharp
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
| | - Alice Shum-Siu
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
| | - Greta M Cesarz
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Jeffrey C Petruska
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky, USA
| | - David S K Magnuson
- Translational Neuroscience Program, University of Louisville, Louisville, Kentucky, USA
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky, USA
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2
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Wang Q, Cheng B, Singh S, Tao Y, Xie Z, Qin F, Shi X, Xu J, Hu C, Tan W, Li H, Huang H. A protein-encoding CCDC7 circular RNA inhibits the progression of prostate cancer by up-regulating FLRT3. NPJ Precis Oncol 2024; 8:11. [PMID: 38225404 PMCID: PMC10789799 DOI: 10.1038/s41698-024-00503-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 01/04/2024] [Indexed: 01/17/2024] Open
Abstract
Circular RNAs (circRNAs) are a family of endogenous RNAs that have become a focus of biological research in recent years. Emerging evidence has revealed that circRNAs exert biological functions by acting as transcriptional regulators, microRNA sponges, and binding partners with RNA-binding proteins. However, few studies have identified coding circRNAs, which may lead to a hidden repertoire of proteins. In this study, we unexpectedly discovered a protein-encoding circular RNA circCCDC7(15,16,17,18,19) while we were searching for prostate cancer related chimeric RNAs. circCCDC7(15,16,17,18,19) is derived from exon 19 back spliced to exon 15 of the CCDC7 gene. It is significantly downregulated in patients with high Gleason score. Prostate cancer patients with decreased circCCDC7(15,16,17,18,19) expression have a worse prognosis, while linear CCDC7 had no such association. Overexpressed circCCDC7(15,16,17,18,19) inhibited prostate cancer cell migration, invasion, and viability, supporting classification of circCCDC7(15,16,17,18,19) as a bona fide tumor suppressor gene. We provide evidence that its tumor suppressive activity is driven by the protein it encodes, and that circCCDC7(15,16,17,18,19) encodes a secretory protein. Consistently, conditioned media from circCCDC7(15,16,17,18,19) overexpressing cells has the same tumor suppressive activity. We further demonstrate that the tumor suppressive activity of circCCDC7(15,16,17,18,19) is at least partially mediated by FLRT3, whose expression also negatively correlates with Gleason score and clinical prognosis. In conclusion, circCCDC7(15,16,17,18,19) functions as a tumor suppressor in prostate cancer cells through the circCCDC7-180aa secretory protein it encodes, and is a promising therapeutic peptide for prostate cancer.
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Affiliation(s)
- Qiong Wang
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Bisheng Cheng
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
| | - Sandeep Singh
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Yiran Tao
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
| | - Zhongqiu Xie
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Fujun Qin
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Xinrui Shi
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Jingjing Xu
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Chenxi Hu
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Wanlong Tan
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Hui Li
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA.
| | - Hai Huang
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China.
- Department of Urology, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan, 511518, China.
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3
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Hills R, Mossman JA, Bratt-Leal AM, Tran H, Williams RM, Stouffer DG, Sokolova IV, Sanna PP, Loring JF, Lelos MJ. Neurite Outgrowth and Gene Expression Profile Correlate with Efficacy of Human Induced Pluripotent Stem Cell-Derived Dopamine Neuron Grafts. Stem Cells Dev 2023; 32:387-397. [PMID: 37166357 PMCID: PMC10398740 DOI: 10.1089/scd.2023.0043] [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: 02/27/2023] [Accepted: 05/08/2023] [Indexed: 05/12/2023] Open
Abstract
Transplantation of human induced pluripotent stem cell-derived dopaminergic (iPSC-DA) neurons is a promising therapeutic strategy for Parkinson's disease (PD). To assess optimal cell characteristics and reproducibility, we evaluated the efficacy of iPSC-DA neuron precursors from two individuals with sporadic PD by transplantation into a hemiparkinsonian rat model after differentiation for either 18 (d18) or 25 days (d25). We found similar graft size and dopamine (DA) neuron content in both groups, but only the d18 cells resulted in recovery of motor impairments. In contrast, we report that d25 grafts survived equally as well and produced grafts rich in tyrosine hydroxylase-positive neurons, but were incapable of alleviating any motor deficits. We identified the mechanism of action as the extent of neurite outgrowth into the host brain, with d18 grafts supporting significantly more neurite outgrowth than nonfunctional d25 grafts. RNAseq analysis of the cell preparation suggests that graft efficacy may be enhanced by repression of differentiation-associated genes by REST, defining the optimal predifferentiation state for transplantation. This study demonstrates for the first time that DA neuron grafts can survive well in vivo while completely lacking the capacity to induce recovery from motor dysfunction. In contrast to other recent studies, we demonstrate that neurite outgrowth is the key factor determining graft efficacy and our gene expression profiling revealed characteristics of the cells that may predict their efficacy. These data have implication for the generation of DA neuron grafts for clinical application.
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Affiliation(s)
- Rachel Hills
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Jim A. Mossman
- Independent Bioinformatics Consultant, Del Mar, California, USA
| | - Andres M. Bratt-Leal
- Department of Molecular Medicine, Center for Regenerative Medicine, Scripps Research, La Jolla, California, USA
- Summit for Stem Cell Foundation, San Diego, California, USA
| | - Ha Tran
- Department of Molecular Medicine, Center for Regenerative Medicine, Scripps Research, La Jolla, California, USA
- Summit for Stem Cell Foundation, San Diego, California, USA
| | - Roy M. Williams
- Department of Molecular Medicine, Center for Regenerative Medicine, Scripps Research, La Jolla, California, USA
| | - David G. Stouffer
- Department of Molecular Medicine, Center for Regenerative Medicine, Scripps Research, La Jolla, California, USA
| | - Irina V. Sokolova
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California, USA
| | - Pietro P. Sanna
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California, USA
| | - Jeanne F. Loring
- Department of Molecular Medicine, Center for Regenerative Medicine, Scripps Research, La Jolla, California, USA
| | - Mariah J. Lelos
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, United Kingdom
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4
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Rouchka EC, de Almeida C, House RB, Daneshmand JC, Chariker JH, Saraswat-Ohri S, Gomes C, Sharp M, Shum-Siu A, Cesarz GM, Petruska JC, Magnuson DS. Construction of a searchable database for gene expression changes in spinal cord injury experiments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526630. [PMID: 36778366 PMCID: PMC9915599 DOI: 10.1101/2023.02.01.526630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Spinal cord injury (SCI) is a debilitating disease resulting in an estimated 18,000 new cases in the United States on an annual basis. Significant behavioral research on animal models has led to a large amount of data, some of which has been catalogued in the Open Data Commons for Spinal Cord Injury (ODC-SCI). More recently, high throughput sequencing experiments have been utilized to understand molecular mechanisms associated with SCI, with nearly 6,000 samples from over 90 studies available in the Sequence Read Archive. However, to date, no resource is available for efficiently mining high throughput sequencing data from SCI experiments. Therefore, we have developed a protocol for processing RNA-Seq samples from high-throughput sequencing experiments related to SCI resulting in both raw and normalized data that can be efficiently mined for comparisons across studies as well as homologous discovery across species. We have processed 1,196 publicly available RNA-seq samples from 50 bulk RNA-Seq studies across nine different species, resulting in an SQLite database that can be used by the SCI research community for further discovery. We provide both the database as well as a web-based front-end that can be used to query the database for genes of interest, differential gene expression, genes with high variance, and gene set enrichments.
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Affiliation(s)
- Eric C. Rouchka
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, University of Louisville, Louisville, KY USA
- Kentucky IDeA Networks of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville School of Medicine, 522 East Gray Street, Louisville, KY USA 40202
- Bioinformatics Program, School of Interdisciplinary and Graduate Studies, University of Louisville, Louisville, KY
| | - Carlos de Almeida
- Translational Neuroscience Program, School of Interdisciplinary and Graduate Studies, University of Louisville, Louisville, KY
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
| | - Randi B. House
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Bioengineering, Speed School of Engineering, University of Louisville, Louisville, KY
| | - Jonah C. Daneshmand
- Bioinformatics Program, School of Interdisciplinary and Graduate Studies, University of Louisville, Louisville, KY
| | - Julia H. Chariker
- Kentucky IDeA Networks of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville School of Medicine, 522 East Gray Street, Louisville, KY USA 40202
- Department of Neuroscience Training, School of Medicine, University of Louisville, Louisville, KY
| | - Sujata Saraswat-Ohri
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY USA
| | - Cynthia Gomes
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY
| | - Morgan Sharp
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY USA
| | - Alice Shum-Siu
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY USA
| | - Greta M. Cesarz
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
| | - Jeffrey C. Petruska
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY USA
- Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY
| | - David S.K. Magnuson
- Translational Neuroscience Program, School of Interdisciplinary and Graduate Studies, University of Louisville, Louisville, KY
- Kentucky Spinal Cord Injury Research Center, School of Medicine, University of Louisville, Louisville, KY
- Department of Neurological Surgery, School of Medicine, University of Louisville, Louisville, KY USA
- Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY
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5
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Li J, Shinoda Y, Ogawa S, Ikegaya S, Li S, Matsuyama Y, Sato K, Yamagishi S. Expression of FLRT2 in Postnatal Central Nervous System Development and After Spinal Cord Injury. Front Mol Neurosci 2021; 14:756264. [PMID: 34744626 PMCID: PMC8569257 DOI: 10.3389/fnmol.2021.756264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/28/2021] [Indexed: 12/24/2022] Open
Abstract
Fibronectin and leucine-rich transmembrane (FLRT) proteins are necessary for various developmental processes and in pathological conditions. FLRT2 acts as a homophilic cell adhesion molecule, a heterophilic repulsive ligand of Unc5/Netrin receptors, and a synaptogenic molecule; the last feature is mediated by binding to latrophilins. Although the function of FLRT2 in regulating cortical migration at the late gestation stage has been analyzed, little is known about the expression pattern of FLRT2 during postnatal central nervous system (CNS) development. In this study, we used Flrt2-LacZ knock-in (KI) mice to analyze FLRT2 expression during CNS development. At the early postnatal stage, FLRT2 expression was largely restricted to several regions of the striatum and deep layers of the cerebral cortex. In adulthood, FLRT2 expression was more prominent in the cerebral cortex, hippocampus, piriform cortex (PIR), nucleus of the lateral olfactory tract (NLOT), and ventral medial nucleus (VM) of the thalamus, but lower in the striatum. Notably, in the hippocampus, FLRT2 expression was confined to the CA1 region and partly localized on pre- and postsynapses whereas only few expression was observed in CA3 and dentate gyrus (DG). Finally, we observed temporally limited FLRT2 upregulation in reactive astrocytes around lesion sites 7 days after thoracic spinal cord injury. These dynamic changes in FLRT2 expression may enable multiple FLRT2 functions, including cell adhesion, repulsion, and synapse formation in different regions during CNS development and after spinal cord injury.
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Affiliation(s)
- Juntan Li
- Department of Organ and Tissue Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yo Shinoda
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Shuhei Ogawa
- Division of Integrated Research, Research Institute for Biomedical Sciences, Tokyo University of Science, Chiba, Japan
| | - Shunsuke Ikegaya
- Department of Organ and Tissue Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Shuo Li
- Department of Organ and Tissue Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan.,Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yukihiro Matsuyama
- Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kohji Sato
- Department of Organ and Tissue Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Satoru Yamagishi
- Department of Organ and Tissue Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Smith HM, Khairallah SM, Nguyen AH, Newman-Smith E, Smith WC. Misregulation of cell adhesion molecules in the Ciona neural tube closure mutant bugeye. Dev Biol 2021; 480:14-24. [PMID: 34407458 DOI: 10.1016/j.ydbio.2021.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/16/2021] [Accepted: 08/10/2021] [Indexed: 11/18/2022]
Abstract
Neural tube closure (NTC) is a complex multi-step morphogenetic process that transforms the flat neural plate found on the surface of the post-gastrulation embryo into the hollow and subsurface central nervous system (CNS). Errors in this process underlie some of the most prevalent human birth defects, and occur in about 1 out of every 1000 births. Previously, we discovered a mutant in the basal chordate Ciona savignyi (named bugeye) that revealed a novel role for a T-Type Calcium Channel (Cav3) in this process. Moreover, the requirement for CAV3s in Xenopus NTC suggests a conserved function among the chordates. Loss of CAV3 leads to defects restricted to anterior NTC, with the brain apparently fully developed, but protruding from the head. Here we report first on a new Cav3 mutant in the related species C. robusta. RNAseq analysis of both C. robusta and C. savignyi bugeye mutants reveals misregulation of a number of transcripts including ones that are involved in cell-cell recognition and adhesion. Two in particular, Selectin and Fibronectin leucine-rich repeat transmembrane, which are aberrantly upregulated in the mutant, are expressed in the closing neural tube, and when disrupted by CRISPR gene editing lead to the open brain phenotype displayed in bugeye mutants. We speculate that these molecules play a transient role in tissue separation and adhesion during NTC and failure to downregulate them leads to an open neural tube.
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Affiliation(s)
- Haley M Smith
- Department of Molecular, Cellular and Developmental Biology, USA
| | | | - Ann Hong Nguyen
- Department of Molecular, Cellular and Developmental Biology, USA
| | | | - William C Smith
- Department of Molecular, Cellular and Developmental Biology, USA; Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.
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7
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Variants in FLRT3 and SLC35E2B identified using exome sequencing in seven high myopia families from Central Europe. Adv Med Sci 2021; 66:192-198. [PMID: 33711669 DOI: 10.1016/j.advms.2021.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 02/09/2021] [Accepted: 02/26/2021] [Indexed: 12/28/2022]
Abstract
PURPOSE High myopia (HM) is an eye disorder with both environmental and genetic factors involved. Many genetic factors responsible for HM were recognized worldwide, but little is known about genetic variants underlying HM in Central Europe. Thus, the aim of this study was to identify rare sequence variants involved in HM in families from Central Europe to better understand the genetic basis of HM. MATERIALS AND METHODS We assessed 17 individuals from 7 unrelated Central European families with hereditary HM using exome sequencing (ES). Segregation of selected variants in other available family members was performed using Sanger sequencing. RESULTS Detected 73 rare variants were selected for verification. We observed 2 missense variants, c.938C>T in SLC35E2B - encoding solute carrier family 35 member E2B, and c.1642G>C in FLRT3 - encoding fibronectin leucine rich transmembrane protein, segregating with HM in one family. CONCLUSIONS FLRT3 and/or SLC35E2B could represent disease candidate genes and identified sequence variants might be responsible for HM in the studied family.
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8
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Peregrina C, Del Toro D. FLRTing Neurons in Cortical Migration During Cerebral Cortex Development. Front Cell Dev Biol 2020; 8:578506. [PMID: 33043013 PMCID: PMC7527468 DOI: 10.3389/fcell.2020.578506] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/17/2020] [Indexed: 01/26/2023] Open
Abstract
During development, two coordinated events shape the morphology of the mammalian cerebral cortex, leading to the cortex's columnar and layered structure: the proliferation of neuronal progenitors and cortical migration. Pyramidal neurons originating from germinal zones migrate along radial glial fibers to their final position in the cortical plate by both radial migration and tangential dispersion. These processes rely on the delicate balance of intercellular adhesive and repulsive signaling that takes place between neurons interacting with different substrates and guidance cues. Here, we focus on the function of the cell adhesion molecules fibronectin leucine-rich repeat transmembrane proteins (FLRTs) in regulating both the radial migration of neurons, as well as their tangential spread, and the impact these processes have on cortex morphogenesis. In combining structural and functional analysis, recent studies have begun to reveal how FLRT-mediated responses are precisely tuned - from forming different protein complexes to modulate either cell adhesion or repulsion in neurons. These approaches provide a deeper understanding of the context-dependent interactions of FLRTs with multiple receptors involved in axon guidance and synapse formation that contribute to finely regulated neuronal migration.
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Affiliation(s)
- Claudia Peregrina
- Department of Biological Sciences, Faculty of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Daniel Del Toro
- Department of Biological Sciences, Faculty of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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9
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Cangiano B, Swee DS, Quinton R, Bonomi M. Genetics of congenital hypogonadotropic hypogonadism: peculiarities and phenotype of an oligogenic disease. Hum Genet 2020; 140:77-111. [PMID: 32200437 DOI: 10.1007/s00439-020-02147-1] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 03/04/2020] [Indexed: 12/30/2022]
Abstract
A genetic basis of congenital isolated hypogonadotropic hypogonadism (CHH) can be defined in almost 50% of cases, albeit not necessarily the complete genetic basis. Next-generation sequencing (NGS) techniques have led to the discovery of a great number of loci, each of which has illuminated our understanding of human gonadotropin-releasing hormone (GnRH) neurons, either in respect of their embryonic development or their neuroendocrine regulation as the "pilot light" of human reproduction. However, because each new gene linked to CHH only seems to underpin another small percentage of total patient cases, we are still far from achieving a comprehensive understanding of the genetic basis of CHH. Patients have generally not benefited from advances in genetics in respect of novel therapies. In most cases, even genetic counselling is limited by issues of apparent variability in expressivity and penetrance that are likely underpinned by oligogenicity in respect of known and unknown genes. Robust genotype-phenotype relationships can generally only be established for individuals who are homozygous, hemizygous or compound heterozygotes for the same gene of variant alleles that are predicted to be deleterious. While certain genes are purely associated with normosmic CHH (nCHH) some purely with the anosmic form (Kallmann syndrome-KS), other genes can be associated with both nCHH and KS-sometimes even within the same kindred. Even though the anticipated genetic overlap between CHH and constitutional delay in growth and puberty (CDGP) has not materialised, previously unanticipated genetic relationships have emerged, comprising conditions of combined (or multiple) pituitary hormone deficiency (CPHD), hypothalamic amenorrhea (HA) and CHARGE syndrome. In this review, we report the current evidence in relation to phenotype and genetic peculiarities regarding 60 genes whose loss-of-function variants can disrupt the central regulation of reproduction at many levels: impairing GnRH neurons migration, differentiation or activation; disrupting neuroendocrine control of GnRH secretion; preventing GnRH neuron migration or function and/or gonadotropin secretion and action.
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Affiliation(s)
- Biagio Cangiano
- Department of Clinical Sciences and Community Health, University of Milan, 20100, Milan, Italy.,Department of Endocrine and Metabolic Diseases and Laboratory of Endocrine and Metabolic Research, IRCCS Istituto Auxologico Italiano, Piazzale Brescia 20, 20149, Milan, Italy
| | - Du Soon Swee
- Department of Endocrinology, Singapore General Hospital, Singapore, Singapore
| | - Richard Quinton
- Endocrine Unit, Royal Victoria Infirmary, Department of Endocrinology, Diabetes and Metabolism, Newcastle-Upon-Tyne Hospitals, Newcastle-Upon-Tyne, NE1 4LP, UK. .,Translational and Clinical Research Institute, University of Newcastle-Upon-Tyne, Newcastle-Upon-Tyne, UK.
| | - Marco Bonomi
- Department of Clinical Sciences and Community Health, University of Milan, 20100, Milan, Italy. .,Department of Endocrine and Metabolic Diseases and Laboratory of Endocrine and Metabolic Research, IRCCS Istituto Auxologico Italiano, Piazzale Brescia 20, 20149, Milan, Italy.
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10
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Increased Expression of Fibronectin Leucine-Rich Transmembrane Protein 3 in the Dorsal Root Ganglion Induces Neuropathic Pain in Rats. J Neurosci 2019; 39:7615-7627. [PMID: 31346030 DOI: 10.1523/jneurosci.0295-19.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/17/2019] [Accepted: 06/06/2019] [Indexed: 01/19/2023] Open
Abstract
Neuropathic pain is a chronic condition that occurs frequently after nerve injury and induces hypersensitivity or allodynia characterized by aberrant neuronal excitability in the spinal cord dorsal horn. Fibronectin leucine-rich transmembrane protein 3 (FLRT3) is a modulator of neurite outgrowth, axon pathfinding, and cell adhesion, which is upregulated in the dorsal horn following peripheral nerve injury. However, the function of FLRT3 in adults remains unknown. Therefore, we aimed to investigate the involvement of spinal FLRT3 in neuropathic pain using rodent models. In the dorsal horns of male rats, FLRT3 protein levels increased at day 4 after peripheral nerve injury. In the DRG, FLRT3 was expressed in activating transcription factor 3-positive, injured sensory neurons. Peripheral nerve injury stimulated Flrt3 transcription in the DRG but not in the spinal cord. Intrathecal administration of FLRT3 protein to naive rats induced mechanical allodynia and GluN2B phosphorylation in the spinal cord. DRG-specific FLRT3 overexpression using adeno-associated virus also produced mechanical allodynia. Conversely, a function-blocking FLRT3 antibody attenuated mechanical allodynia after partial sciatic nerve ligation. Therefore, FLRT3 derived from injured DRG neurons increases dorsal horn excitability and induces mechanical allodynia.SIGNIFICANCE STATEMENT Neuropathic pain occurs frequently after nerve injury and is associated with abnormal neuronal excitability in the spinal cord. Fibronectin leucine-rich transmembrane protein 3 (FLRT3) regulates neurite outgrowth and cell adhesion. Here, nerve injury increased FLRT3 protein levels in the spinal cord dorsal root, despite the fact that Flrt3 transcripts were only induced in the DRG. FLRT3 protein injection into the rat spinal cord induced mechanical hypersensitivity, as did virus-mediated FLRT3 overexpression in DRG. Conversely, FLRT3 inhibition with antibodies attenuated mechanically induced pain after nerve damage. These findings suggest that FLRT3 is produced by injured DRG neurons and increases neuronal excitability in the dorsal horn, leading to pain sensitization. Neuropathic pain induction is a novel function of FLRT3.
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Cho HJ, Shan Y, Whittington NC, Wray S. Nasal Placode Development, GnRH Neuronal Migration and Kallmann Syndrome. Front Cell Dev Biol 2019; 7:121. [PMID: 31355196 PMCID: PMC6637222 DOI: 10.3389/fcell.2019.00121] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/14/2019] [Indexed: 12/22/2022] Open
Abstract
The development of Gonadotropin releasing hormone-1 (GnRH) neurons is important for a functional reproduction system in vertebrates. Disruption of GnRH results in hypogonadism and if accompanied by anosmia is termed Kallmann Syndrome (KS). From their origin in the nasal placode, GnRH neurons migrate along the olfactory-derived vomeronasal axons to the nasal forebrain junction and then turn caudally into the developing forebrain. Although research on the origin of GnRH neurons, their migration and genes associated with KS has identified multiple factors that influence development of this system, several aspects still remain unclear. This review discusses development of the olfactory system, factors that regulate GnRH neuron formation and development of the olfactory system, migration of the GnRH neurons from the nose into the brain, and mutations in humans with KS that result from disruption of normal GnRH/olfactory systems development.
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Affiliation(s)
- Hyun-Ju Cho
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Yufei Shan
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Niteace C Whittington
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Susan Wray
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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12
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Jauhiainen S, Laakkonen JP, Ketola K, Toivanen PI, Nieminen T, Ninchoji T, Levonen AL, Kaikkonen MU, Ylä-Herttuala S. Axon Guidance-Related Factor FLRT3 Regulates VEGF-Signaling and Endothelial Cell Function. Front Physiol 2019; 10:224. [PMID: 30930791 PMCID: PMC6423482 DOI: 10.3389/fphys.2019.00224] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/21/2019] [Indexed: 11/13/2022] Open
Abstract
Vascular endothelial growth factors (VEGFs) are key mediators of endothelial cell (EC) function in angiogenesis. Emerging knowledge also supports the involvement of axon guidance-related factors in the regulation of angiogenesis and vascular patterning. In the current study, we demonstrate that fibronectin and leucine-rich transmembrane protein-3 (FLRT3), an axon guidance-related factor connected to the regulation of neuronal cell outgrowth and morphogenesis but not to VEGF-signaling, was upregulated in ECs after VEGF binding to VEGFR2. We found that FLRT3 exhibited a transcriptionally paused phenotype in non-stimulated human umbilical vein ECs. After VEGF-stimulation its nascent RNA and mRNA-levels were rapidly upregulated suggesting that the regulation of FLRT3 expression is mainly occurring at the level of transcriptional elongation. Blockage of FLRT3 by siRNA decreased survival of ECs and their arrangement into capillary-like structures but enhanced cell migration and wound closure in wound healing assay. Bifunctional role of FLRT3 in repulsive vs. adhesive cell signaling has been already detected during embryogenesis and neuronal growth, and depends on its interactions either with UNC5B or another FLRT3 expressed by adjacent cells. In conclusion, our findings demonstrate that besides regulating neuronal cell outgrowth and morphogenesis, FLRT3 has a novel role in ECs via regulating VEGF-stimulated EC-survival, migration, and tube formation. Thus, FLRT3 becomes a new member of the axon guidance-related factors which participate in the VEGF-signaling and regulation of the EC functions.
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Affiliation(s)
- Suvi Jauhiainen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.,Rudbeck Laboratory, University of Uppsala, Uppsala, Sweden
| | - Johanna P Laakkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Kirsi Ketola
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Pyry I Toivanen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Tiina Nieminen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | | | - Anna-Liisa Levonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Minna U Kaikkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Seppo Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.,Heart Center and Gene Therapy Unit, Kuopio University Hospital, Kuopio, Finland
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13
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Liu X, Su P, Lu L, Feng Z, Wang H, Zhou J. Function of FEZF1 during early neural differentiation of human embryonic stem cells. SCIENCE CHINA-LIFE SCIENCES 2018; 61:35-45. [PMID: 29318501 DOI: 10.1007/s11427-017-9155-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/19/2017] [Indexed: 12/14/2022]
Abstract
The understanding of the mechanism underlying human neural development has been hampered due to lack of a cellular system and complicated ethical issues. Human embryonic stem cells (hESCs) provide an invaluable model for dissecting human development because of unlimited self-renewal and the capacity to differentiate into nearly all cell types in the human body. In this study, using a chemical defined neural induction protocol and molecular profiling, we identified Fez family zinc finger 1 (FEZF1) as a potential regulator of early human neural development. FEZF1 is rapidly up-regulated during neural differentiation in hESCs and expressed before PAX6, a well-established marker of early human neural induction. We generated FEZF1-knockout H1 hESC lines using CRISPR-CAS9 technology and found that depletion of FEZF1 abrogates neural differentiation of hESCs. Moreover, loss of FEZF1 impairs the pluripotency exit of hESCs during neural specification, which partially explains the neural induction defect caused by FEZF1 deletion. However, enforced expression of FEZF1 itself fails to drive neural differentiation in hESCs, suggesting that FEZF1 is necessary but not sufficient for neural differentiation from hESCs. Taken together, our findings identify one of the earliest regulators expressed upon neural induction and provide insight into early neural development in human.
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Affiliation(s)
- Xin Liu
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Pei Su
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Lisha Lu
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Zicen Feng
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Hongtao Wang
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China.
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China.
| | - Jiaxi Zhou
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China.
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China.
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14
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Weiss T, Taschner-Mandl S, Bileck A, Slany A, Kromp F, Rifatbegovic F, Frech C, Windhager R, Kitzinger H, Tzou CH, Ambros PF, Gerner C, Ambros IM. Proteomics and transcriptomics of peripheral nerve tissue and cells unravel new aspects of the human Schwann cell repair phenotype. Glia 2016; 64:2133-2153. [DOI: 10.1002/glia.23045] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/21/2016] [Accepted: 07/26/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Tamara Weiss
- Children's Cancer Research Institute; Vienna Austria
| | | | - Andrea Bileck
- Department of Analytical Chemistry; University of Vienna; Vienna Austria
| | - Astrid Slany
- Department of Analytical Chemistry; University of Vienna; Vienna Austria
| | - Florian Kromp
- Children's Cancer Research Institute; Vienna Austria
| | | | | | - Reinhard Windhager
- Department of Orthopedic Surgery; Medical University of Vienna; Vienna Austria
| | - Hugo Kitzinger
- Department of Plastic and Reconstructive Surgery; Medical University of Vienna; Vienna Austria
| | - Chieh-Han Tzou
- Department of Plastic and Reconstructive Surgery; Medical University of Vienna; Vienna Austria
| | - Peter F. Ambros
- Children's Cancer Research Institute; Vienna Austria
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Christopher Gerner
- Department of Analytical Chemistry; University of Vienna; Vienna Austria
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15
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Regulation of FGF signaling: Recent insights from studying positive and negative modulators. Semin Cell Dev Biol 2016; 53:101-14. [DOI: 10.1016/j.semcdb.2016.01.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 01/19/2016] [Indexed: 11/19/2022]
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16
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Akita T, Kumada T, Yoshihara SI, Egea J, Yamagishi S. Ion channels, guidance molecules, intracellular signaling and transcription factors regulating nervous and vascular system development. J Physiol Sci 2015; 66:175-88. [PMID: 26507418 PMCID: PMC4752580 DOI: 10.1007/s12576-015-0416-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 09/30/2015] [Indexed: 01/13/2023]
Abstract
Our sophisticated thoughts and behaviors are based on the miraculous development of our complex nervous network system, in which many different types of proteins and signaling cascades are regulated in a temporally and spatially ordered manner. Here we review our recent attempts to grasp the principles of nervous system development in terms of general cellular phenomena and molecules, such as volume-regulated anion channels, intracellular Ca2+ and cyclic nucleotide signaling, the Npas4 transcription factor and the FLRT family of axon guidance molecules. We also present an example illustrating that the same FLRT family may regulate the development of vascular networks as well. The aim of this review is to open up new vistas for understanding the intricacy of nervous and vascular system development.
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Affiliation(s)
- Tenpei Akita
- Department of Neurophysiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan.
| | - Tatsuro Kumada
- Department of Occupational Therapy, Faculty of Health and Medical Sciences, Tokoha University, 1230 Miyakoda-cho, Kita-ku, Hamamatsu, Shizuoka, 431-2102, Japan
| | - Sei-ichi Yoshihara
- Laboratory for Molecular Biology of Neural System, Advanced Medical Research Center, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan
| | - Joaquim Egea
- Molecular and Developmental Neurobiology Group, Biomedical Research Institute of Lleida (IRBLleida), University of Lleida, 25198, Lleida, Spain
| | - Satoru Yamagishi
- Department of Anatomy and Neuroscience, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan
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17
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Flintoff KA, Arudchelvan Y, Gong SG. FLRT2 interacts with fibronectin in the ATDC5 chondroprogenitor cells. J Cell Physiol 2014; 229:1538-47. [PMID: 24585683 DOI: 10.1002/jcp.24597] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 02/26/2014] [Indexed: 01/03/2023]
Abstract
Expression studies have implicated FLRT2 in cranial neural crest cell migration and prechondrogenic cell condensation during craniofacial skeletogenesis. We aimed to determine whether FLRT2 was involved in mediating cell-matrix interactions in the ATDC5 chondroprogenitor cell line. Immunolocalization experiments of ATDC5 cells revealed that FLRT2 was present on the cell membrane as well as extracellularly, where it colocalized with Fibronectin (Fn). After cell extraction of the matrix, FLRT2 was identified in the ATDC5-derived extracellular matrix (ECM) and was further found to be associated with Fn-coated beads in cell cultures. Blockage of Fn fibril formation via a blocking peptide resulted in a concomitant decrease in extracellular FLRT2 accumulation. Over a 7-day period following the replenishment of the Fn blocking peptide to the cultures, there was a partial rebound in Fn fibril formation that was accompanied by a concomitant reappearance of FLRT2 co-expression. Co-immunoprecipitation confirmed that FLRT2 and Fn interacted, either directly or indirectly. Immunoprecipitation and Western blot analyses with antibodies recognizing epitopes located on the extra- and intracellular domains of FLRT2 further revealed the presence of different sized bands, suggesting that FLRT2 may exist in both membrane-bound and shed forms. Our data therefore provide evidence that FLRT2 and/or its cleavage products may be cooperating with Fn and other ECM proteins to regulate critical cellular events. Further studies will be necessary in delineate more precisely the roles of FLRT2 in mediating cell- and cell-matrix interactions during normal development.
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Affiliation(s)
- K A Flintoff
- Department of Orthodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
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18
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Lowery LA. Axon guidance: FLRTing promotes attraction. Curr Biol 2014; 24:R198-200. [PMID: 24602885 DOI: 10.1016/j.cub.2014.01.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A recent study demonstrates a new mechanism by which crosstalk between multiple guidance cues is integrated during axon pathfinding. FLRT3 is a novel co-receptor for Robo1 that acts as a context-dependent modulator of Netrin-1 attraction in thalamocortical axons.
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Affiliation(s)
- Laura Anne Lowery
- Department of Biology, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA.
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19
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Winther M, Walmod PS. Neural cell adhesion molecules belonging to the family of leucine-rich repeat proteins. ADVANCES IN NEUROBIOLOGY 2014; 8:315-95. [PMID: 25300143 DOI: 10.1007/978-1-4614-8090-7_14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Leucine-rich repeats (LRRs) are motifs that form protein-ligand interaction domains. There are approximately 140 human genes encoding proteins with extracellular LRRs. These encode cell adhesion molecules (CAMs), proteoglycans, G-protein-coupled receptors, and other types of receptors. Here we give a brief description of 36 proteins with extracellular LRRs that all can be characterized as CAMs or putative CAMs expressed in the nervous system. The proteins are involved in multiple biological processes in the nervous system including the proliferation and survival of cells, neuritogenesis, axon guidance, fasciculation, myelination, and the formation and maintenance of synapses. Moreover, the proteins are functionally implicated in multiple diseases including cancer, hearing impairment, glaucoma, Alzheimer's disease, multiple sclerosis, Parkinson's disease, autism spectrum disorders, schizophrenia, and obsessive-compulsive disorders. Thus, LRR-containing CAMs constitute a large group of proteins of pivotal importance for the development, maintenance, and regeneration of the nervous system.
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20
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Boucard AA, Maxeiner S, Südhof TC. Latrophilins function as heterophilic cell-adhesion molecules by binding to teneurins: regulation by alternative splicing. J Biol Chem 2013; 289:387-402. [PMID: 24273166 DOI: 10.1074/jbc.m113.504779] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Latrophilin-1, -2, and -3 are adhesion-type G protein-coupled receptors that are auxiliary α-latrotoxin receptors, suggesting that they may have a synaptic function. Using pulldowns, we here identify teneurins, type II transmembrane proteins that are also candidate synaptic cell-adhesion molecules, as interactors for the lectin-like domain of latrophilins. We show that teneurin binds to latrophilins with nanomolar affinity and that this binding mediates cell adhesion, consistent with a role of teneurin binding to latrophilins in trans-synaptic interactions. All latrophilins are subject to alternative splicing at an N-terminal site; in latrophilin-1, this alternative splicing modulates teneurin binding but has no effect on binding of latrophilin-1 to another ligand, FLRT3. Addition to cultured neurons of soluble teneurin-binding fragments of latrophilin-1 decreased synapse density, suggesting that latrophilin binding to teneurin may directly or indirectly influence synapse formation and/or maintenance. These observations are potentially intriguing in view of the proposed role for Drosophila teneurins in determining synapse specificity. However, teneurins in Drosophila were suggested to act as homophilic cell-adhesion molecules, whereas our findings suggest a heterophilic interaction mechanism. Thus, we tested whether mammalian teneurins also are homophilic cell-adhesion molecules, in addition to binding to latrophilins as heterophilic cell-adhesion molecules. Strikingly, we find that although teneurins bind to each other in solution, homophilic teneurin-teneurin binding is unable to support stable cell adhesion, different from heterophilic teneurin-latrophilin binding. Thus, mammalian teneurins act as heterophilic cell-adhesion molecules that may be involved in trans-neuronal interaction processes such as synapse formation or maintenance.
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Affiliation(s)
- Antony A Boucard
- From the Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Palo Alto, California 94305
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21
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Miraoui H, Dwyer AA, Sykiotis GP, Plummer L, Chung W, Feng B, Beenken A, Clarke J, Pers TH, Dworzynski P, Keefe K, Niedziela M, Raivio T, Crowley WF, Seminara SB, Quinton R, Hughes VA, Kumanov P, Young J, Yialamas MA, Hall JE, Van Vliet G, Chanoine JP, Rubenstein J, Mohammadi M, Tsai PS, Sidis Y, Lage K, Pitteloud N. Mutations in FGF17, IL17RD, DUSP6, SPRY4, and FLRT3 are identified in individuals with congenital hypogonadotropic hypogonadism. Am J Hum Genet 2013; 92:725-43. [PMID: 23643382 DOI: 10.1016/j.ajhg.2013.04.008] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 03/14/2013] [Accepted: 04/10/2013] [Indexed: 12/22/2022] Open
Abstract
Congenital hypogonadotropic hypogonadism (CHH) and its anosmia-associated form (Kallmann syndrome [KS]) are genetically heterogeneous. Among the >15 genes implicated in these conditions, mutations in FGF8 and FGFR1 account for ~12% of cases; notably, KAL1 and HS6ST1 are also involved in FGFR1 signaling and can be mutated in CHH. We therefore hypothesized that mutations in genes encoding a broader range of modulators of the FGFR1 pathway might contribute to the genetics of CHH as causal or modifier mutations. Thus, we aimed to (1) investigate whether CHH individuals harbor mutations in members of the so-called "FGF8 synexpression" group and (2) validate the ability of a bioinformatics algorithm on the basis of protein-protein interactome data (interactome-based affiliation scoring [IBAS]) to identify high-quality candidate genes. On the basis of sequence homology, expression, and structural and functional data, seven genes were selected and sequenced in 386 unrelated CHH individuals and 155 controls. Except for FGF18 and SPRY2, all other genes were found to be mutated in CHH individuals: FGF17 (n = 3 individuals), IL17RD (n = 8), DUSP6 (n = 5), SPRY4 (n = 14), and FLRT3 (n = 3). Independently, IBAS predicted FGF17 and IL17RD as the two top candidates in the entire proteome on the basis of a statistical test of their protein-protein interaction patterns to proteins known to be altered in CHH. Most of the FGF17 and IL17RD mutations altered protein function in vitro. IL17RD mutations were found only in KS individuals and were strongly linked to hearing loss (6/8 individuals). Mutations in genes encoding components of the FGF pathway are associated with complex modes of CHH inheritance and act primarily as contributors to an oligogenic genetic architecture underlying CHH.
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Affiliation(s)
- Hichem Miraoui
- Faculty of Biology and Medicine, University of Lausanne in collaboration with Service of Endocrinology, Diabetology, and Metabolism, Centre Hospitalier Universitaire Vaudois, Rue du Bugnon 7, Lausanne CH-1005, Switzerland
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Xu Y, Wei K, Kulyk W, Gong SG. FLRT2 promotes cellular proliferation and inhibits cell adhesion during chondrogenesis. J Cell Biochem 2012; 112:3440-8. [PMID: 21769912 DOI: 10.1002/jcb.23271] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
One of the earliest events during chondrogenesis is the formation of condensations, a necessary pre-requisite for subsequent differentiation of a chondrogenic phenotype. Members of the Fibronectin Lecucine Rich Transmembrane (FLRT) proteins have been shown to be involved in cell sorting and neurite outgrowth. Additionally, FLRT2 is highly expressed at putative sites of chondrogenic differentiation during craniofacial development. In this study, we demonstrate that FLRT2 plays a role in mediating cell proliferation and cell-cell interactions during early chondrogenesis. Clones of stable transfectants of a murine chondroprogenitor cell line, ATDC5, were established in which FLRT2 was knocked down or overexpressed. Cells in which FLRT2 was knocked down proliferated at a slower rate compared to control wild-type ATDC5 cells or those containing a non-coding shRNA. In addition, FLRT2 knockdown cells formed numerous lectin peanut agglutinin (PNA) stained aggregates and exhibited higher expression of the cell adhesion molecule, N-cadherin. In an in vitro wound healing assay, fewer FLRT2 knockdown cells appeared to migrate into the defect. Surprisingly, the FLRT2 knockdown cells demonstrated increased formation of Alcian blue-stainable extracellular matrix, suggesting that their reduced aggregate formation did not inhibit subsequent chondrogenic differentiation. The opposite trends were observed in ATDC5 clones that overexpressed FLRT2. Specifically, FLRT overexpressing cells proliferated faster, formed fewer PNA-positive aggregates, accumulated increased Alcian blue-positive matrix, and migrated faster to close a wound. Collectively, our findings provide evidence for a role of FLRT2 in enhancing cell proliferation and reducing intercellular adhesion during the early stages of chondrogenesis.
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Affiliation(s)
- Y Xu
- Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ontario, Canada M5G 1G6
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Proenca CC, Gao KP, Shmelkov SV, Rafii S, Lee FS. Slitrks as emerging candidate genes involved in neuropsychiatric disorders. Trends Neurosci 2012; 34:143-53. [PMID: 21315458 DOI: 10.1016/j.tins.2011.01.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 01/09/2011] [Accepted: 01/10/2011] [Indexed: 02/06/2023]
Abstract
Slitrks are a family of structurally related transmembrane proteins belonging to the leucine-rich repeat (LRR) superfamily. Six family members exist (Slitrk1-6) and all are highly expressed in the central nervous system (CNS). Slitrks have been implicated in mediating basic neuronal processes, ranging from neurite outgrowth and dendritic elaboration to neuronal survival. Recent studies in humans and genetic mouse models have led to the identification of Slitrks as candidate genes that might be involved in the development of neuropsychiatric conditions, such as obsessive compulsive spectrum disorders and schizophrenia. Although these system-level approaches have suggested that Slitrks play prominent roles in CNS development, key questions remain regarding the molecular mechanisms through which they mediate neuronal signaling and connectivity.
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Affiliation(s)
- Catia C Proenca
- Department of Psychiatry, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA.
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24
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Wei K, Xu Y, Tse H, Manolson M, Gong SG. Mouse FLRT2 Interacts with the Extracellular and Intracellular Regions of FGFR2. J Dent Res 2011; 90:1234-9. [DOI: 10.1177/0022034511415272] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Fibroblast Growth Factor (FGF) signaling is known to be critical in mediating key developmental events during craniofacial development. Recent evidence suggests that members of the Fibronectin (F) Leucine (L) Rich (R) Transmembrane (T), FLRT, family modulate FGF signaling. FLRT2 has a highly specific pattern of expression during craniofacial development, in close relationship with FGFR2. We therefore characterized FLRT2/FGFR2 interactions in the context of craniofacial development and showed, by co-immunoprecipitation and GST pulldown assays with embryonic craniofacial tissue lysates, that FLRT2 interacted with FGFR2. Yeast two-hybrid assays further showed that the intracellular regions of both proteins interacted in addition to the interactions in the extracellular portions. The extracellular Leucine Rich Repeats domain of FLRT2 contributed to the interactions with the extracellular regions of FGFR2. Interactions in the intracellular regions of the 2 proteins were mediated by the C-tail domain in FLRT2. Furthermore, cells stably transfected with FLRT2 shRNAs or FLRT2 cDNA exhibited a concomitant decrease and increase, respectively, in FGFR2 protein, mRNA, and ERK phosphorylation levels, suggesting a positive feedback regulatory loop of FLRT2 on FGF signaling in craniofacial tissues. We propose that FLRT2-FGFR2 interactions represent a potential mechanism for regulation of FGF signaling by FLRT2 during craniofacial development.
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Affiliation(s)
- K. Wei
- Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada, M5G 1G6
| | - Y. Xu
- Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada, M5G 1G6
- currently, Faculty of Stomatology, Kunming Medical College, No. 191, West Renming Road, Kunming, P.R. China
| | - H. Tse
- Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada, M5G 1G6
| | - M.F. Manolson
- Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada, M5G 1G6
| | - S.-G. Gong
- Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada, M5G 1G6
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FLRT2 and FLRT3 act as repulsive guidance cues for Unc5-positive neurons. EMBO J 2011; 30:2920-33. [PMID: 21673655 DOI: 10.1038/emboj.2011.189] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 05/20/2011] [Indexed: 11/08/2022] Open
Abstract
Netrin-1 induces repulsive axon guidance by binding to the mammalian Unc5 receptor family (Unc5A-Unc5D). Mouse genetic analysis of selected members of the Unc5 family, however, revealed essential functions independent of Netrin-1, suggesting the presence of other ligands. Unc5B was recently shown to bind fibronectin and leucine-rich transmembrane protein-3 (FLRT3), although the relevance of this interaction for nervous system development remained unclear. Here, we show that the related Unc5D receptor binds specifically to another FLRT protein, FLRT2. During development, FLRT2/3 ectodomains (ECDs) are shed from neurons and act as repulsive guidance molecules for axons and somata of Unc5-positive neurons. In the developing mammalian neocortex, Unc5D is expressed by neurons in the subventricular zone (SVZ), which display delayed migration to the FLRT2-expressing cortical plate (CP). Deletion of either FLRT2 or Unc5D causes a subset of SVZ-derived neurons to prematurely migrate towards the CP, whereas overexpression of Unc5D has opposite effects. Hence, the shed FLRT2 and FLRT3 ECDs represent a novel family of chemorepellents for Unc5-positive neurons and FLRT2/Unc5D signalling modulates cortical neuron migration.
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Abstract
Recent studies have identified the leucine rich repeat protein LRRTM2 as a post-synaptic ligand of Neurexins. Neurexins also bind the post-synaptic adhesion molecules, Neuroligins. All three families of genes have been implicated in the etiologies of neurodevelopmental disorders, specifically autism spectrum disorders and schizophrenia. Does the binding promiscuity of Neurexins now suggest complex cooperativity or redundancy at the synapse? While recent studies in primary neuronal cultures and also systematic extracellular protein interaction screens suggest summative effects of these systems, we propose that studying these interactions in the developing zebrafish embryo or larvae may shed more light on their functions during synaptogenesis in vivo. These gene families have recently been extensively characterized in zebrafish, demonstrating high sequence conservation with the human genes. The simpler circuitry of the zebrafish, together with the characterization of the expression patterns down to single, identifiable neurons and the ability to knock-down or over-express multiple genes in a rapid way lend themselves to dissecting complex interaction pathways. Furthermore, the capability of performing high-throughput drug screens suggests that these small vertebrates may prove extremely useful in identifying pharmacological approaches to treating autism spectrum disorders.
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Affiliation(s)
| | - Philip Washbourne
- Institute of Neuroscience, University of Oregon, Eugene OR 97403, USA
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Wheldon LM, Haines BP, Rajappa R, Mason I, Rigby PW, Heath JK. Critical role of FLRT1 phosphorylation in the interdependent regulation of FLRT1 function and FGF receptor signalling. PLoS One 2010; 5:e10264. [PMID: 20421966 PMCID: PMC2858647 DOI: 10.1371/journal.pone.0010264] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 03/25/2010] [Indexed: 01/03/2023] Open
Abstract
Background Fibronectin leucine rich transmembrane (FLRT) proteins have dual properties as regulators of cell adhesion and potentiators of fibroblast growth factor (FGF) mediated signalling. The mechanism by which the latter is achieved is still unknown and is the subject of this investigation. Principal Findings Here we show that FLRT1 is a target for tyrosine phosphorylation mediated by FGFR1 and implicate a non-receptor Src family kinase (SFK). We identify the target tyrosine residues in the cytoplasmic domain of FLRT1 and show that these are not direct substrates for Src kinase suggesting that the SFK may exert effects via potentiation of FGFR1 kinase activity. We show that whilst FLRT1 expression results in a ligand-dependent elevation of MAP kinase activity, a mutant version of FLRT1, defective as an FGFR1 kinase substrate (Y3F-FLRT1), has the property of eliciting ligand-independent chronic activation of the MAP kinase pathway which is suppressed by pharmacological inhibition of either FGFR1 or Src kinase. Functional investigation of FGFR1 and FLRT1 signalling in SH-SY5Y neuroblastoma cells reveals that FLRT1 alone acts to induce a multi-polar phenotype whereas the combination of FLRT1 and FGFR activation, or expression of Y3F-FLRT1, acts to induce neurite outgrowth via MAPK activation. Similar results were obtained in a dendrite outgrowth assay in primary hippocampal neurons. We also show that FGFR1, FLRT1 and activated Src are co-localized and this complex is trafficked toward the soma of the cell. The presence of Y3F-FLRT1 rather than FLRT1 resulted in prolonged localization of this complex within the neuritic arbour. Conclusions This study shows that the phosphorylation state of FLRT1, which is itself FGFR1 dependent, may play a critical role in the potentiation of FGFR1 signalling and may also depend on a SFK-dependent phosphorylation mechanism acting via the FGFR. This is consistent with an ‘in vivo’ role for FLRT1 regulation of FGF signalling via SFKs. Furthermore, the phosphorylation-dependent futile cycle mechanism controlling FGFR1 signalling is concurrently crucial for regulation of FLRT1-mediated neurite outgrowth.
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Affiliation(s)
- Lee M. Wheldon
- Molecular Bacteriology and Immunology Group (MBIG), Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Bryan P. Haines
- Section of Gene Function and Regulation, The Institute of Cancer Research, Chester Beatty Laboratories, London, United Kingdom
| | - Rajit Rajappa
- MRC Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Ivor Mason
- MRC Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Peter W. Rigby
- Section of Gene Function and Regulation, The Institute of Cancer Research, Chester Beatty Laboratories, London, United Kingdom
| | - John K. Heath
- Cancer Research UK Growth Factor Group, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- * E-mail:
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Debette S, Bis JC, Fornage M, Schmidt H, Ikram MA, Sigurdsson S, Heiss G, Struchalin M, Smith AV, van der Lugt A, DeCarli C, Lumley T, Knopman DS, Enzinger C, Eiriksdottir G, Koudstaal PJ, DeStefano AL, Psaty BM, Dufouil C, Catellier DJ, Fazekas F, Aspelund T, Aulchenko YS, Beiser A, Rotter JI, Tzourio C, Shibata DK, Tscherner M, Harris TB, Rivadeneira F, Atwood LD, Rice K, Gottesman RF, van Buchem MA, Uitterlinden AG, Kelly-Hayes M, Cushman M, Zhu Y, Boerwinkle E, Gudnason V, Hofman A, Romero JR, Lopez O, van Duijn CM, Au R, Heckbert SR, Wolf PA, Mosley TH, Seshadri S, Breteler MMB, Schmidt R, Launer LJ, Longstreth WT. Genome-wide association studies of MRI-defined brain infarcts: meta-analysis from the CHARGE Consortium. Stroke 2009; 41:210-7. [PMID: 20044523 DOI: 10.1161/strokeaha.109.569194] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Previous studies examining genetic associations with MRI-defined brain infarct have yielded inconsistent findings. We investigated genetic variation underlying covert MRI infarct in persons without histories of transient ischemic attack or stroke. We performed meta-analysis of genome-wide association studies of white participants in 6 studies comprising the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium. METHODS Using 2.2 million genotyped and imputed single nucleotide polymorphisms, each study performed cross-sectional genome-wide association analysis of MRI infarct using age- and sex-adjusted logistic regression models. Study-specific findings were combined in an inverse-variance-weighted meta-analysis, including 9401 participants with mean age 69.7 (19.4% of whom had >or=1 MRI infarct). RESULTS The most significant association was found with rs2208454 (minor allele frequency, 20%), located in intron 3 of MACRO domain containing 2 gene and in the downstream region of fibronectin leucine-rich transmembrane protein 3 gene. Each copy of the minor allele was associated with lower risk of MRI infarcts (odds ratio, 0.76; 95% confidence interval, 0.68-0.84; P=4.64x10(-7)). Highly suggestive associations (P<1.0x10(-5)) were also found for 22 other single nucleotide polymorphisms in linkage disequilibrium (r(2)>0.64) with rs2208454. The association with rs2208454 did not replicate in independent samples of 1822 white and 644 black participants, although 4 single nucleotide polymorphisms within 200 kb from rs2208454 were associated with MRI infarcts in the black population sample. CONCLUSIONS This first community-based, genome-wide association study on covert MRI infarcts uncovered novel associations. Although replication of the association with top single nucleotide polymorphisms failed, possibly because of insufficient power, results in the black population sample are encouraging, and further efforts at replication are needed.
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Affiliation(s)
- Stéphanie Debette
- Department of Neurology, Boston University School of Medicine, Boston, Mass, USA
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Chen X, Koh E, Yoder M, Gumbiner BM. A protocadherin-cadherin-FLRT3 complex controls cell adhesion and morphogenesis. PLoS One 2009; 4:e8411. [PMID: 20027292 PMCID: PMC2791867 DOI: 10.1371/journal.pone.0008411] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Accepted: 11/30/2009] [Indexed: 11/19/2022] Open
Abstract
Background Paraxial protocadherin (PAPC) and fibronectin leucine-rich domain transmembrane protein-3 (FLRT3) are induced by TGFβ signaling in Xenopus embryos and both regulate morphogenesis by inhibiting C-cadherin mediated cell adhesion. Principal Findings We have investigated the functional and physical relationships between PAPC, FLRT3, and C-cadherin. Although neither PAPC nor FLRT3 are required for each other to regulate C-cadherin adhesion, they do interact functionally and physically, and they form a complex with cadherins. By itself PAPC reduces cell adhesion physiologically to induce cell sorting, while FLRT3 disrupts adhesion excessively to cause cell dissociation. However, when expressed together PAPC limits the cell dissociating and tissue disrupting activity of FLRT3 to make it effective in physiological cell sorting. PAPC counteracts FLRT3 function by inhibiting the recruitment of the GTPase RND1 to the FLRT3 cytoplasmic domain. Conclusions/Significance PAPC and FLRT3 form a functional complex with cadherins and PAPC functions as a molecular “governor” to maintain FLRT3 activity at the optimal level for physiological regulation of C-cadherin adhesion, cell sorting, and morphogenesis.
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Affiliation(s)
- Xuejun Chen
- Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, Virginia, United States of America
| | - Eunjin Koh
- Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, Virginia, United States of America
| | - Michael Yoder
- Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, Virginia, United States of America
| | - Barry M. Gumbiner
- Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, Virginia, United States of America
- * E-mail:
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Flrt2 and Flrt3 have overlapping and non-overlapping expression during craniofacial development. Gene Expr Patterns 2009; 9:497-502. [DOI: 10.1016/j.gep.2009.07.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 07/10/2009] [Accepted: 07/11/2009] [Indexed: 01/04/2023]
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Söllner C, Wright GJ. A cell surface interaction network of neural leucine-rich repeat receptors. Genome Biol 2009; 10:R99. [PMID: 19765300 PMCID: PMC2768988 DOI: 10.1186/gb-2009-10-9-r99] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 08/18/2009] [Accepted: 09/18/2009] [Indexed: 01/18/2023] Open
Abstract
A network of Zebrafish extracellular neuroreceptor interactions are revealed using AVEXIS, a highly stringent interaction assay. Background The vast number of precise intercellular connections within vertebrate nervous systems is only partly explained by the comparatively few known extracellular guidance cues. Large families of neural orphan receptor proteins have been identified and are likely to contribute to these recognition processes but due to the technical difficulty in identifying novel extracellular interactions of membrane-embedded proteins, their ligands remain unknown. Results To identify novel neural recognition signals, we performed a large systematic protein interaction screen using an assay capable of detecting low affinity extracellular protein interactions between the ectodomains of 150 zebrafish receptor proteins containing leucine-rich-repeat and/or immunoglobulin superfamily domains. We screened 7,592 interactions to construct a network of 34 cell surface receptor-ligand pairs that included orphan receptor subfamilies such as the Lrrtms, Lrrns and Elfns but also novel ligands for known receptors such as Robos and Unc5b. A quantitative biochemical analysis of a subnetwork involving the Unc5b and three Flrt receptors revealed a surprising quantitative variation in receptor binding strengths. Paired spatiotemporal gene expression patterns revealed dynamic neural receptor recognition maps within the developing nervous system, providing biological support for the network and revealing likely functions. Conclusions This integrated interaction and expression network provides a rich source of novel neural recognition pathways and highlights the importance of quantitative systematic extracellular protein interaction screens to mechanistically explain neural wiring patterns.
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Affiliation(s)
- Christian Söllner
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1HH, UK.
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Karaulanov E, Böttcher RT, Stannek P, Wu W, Rau M, Ogata S, Cho KWY, Niehrs C. Unc5B interacts with FLRT3 and Rnd1 to modulate cell adhesion in Xenopus embryos. PLoS One 2009; 4:e5742. [PMID: 19492039 PMCID: PMC2683942 DOI: 10.1371/journal.pone.0005742] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 04/27/2009] [Indexed: 12/29/2022] Open
Abstract
The FLRT family of transmembrane proteins has been implicated in the regulation of FGF signalling, neurite outgrowth, homotypic cell sorting and cadherin-mediated adhesion. In an expression screen we identified the Netrin receptors Unc5B and Unc5D as high-affinity FLRT3 interactors. Upon overexpression, Unc5B phenocopies FLRT3 and both proteins synergize in inducing cell deadhesion in Xenopus embryos. Morpholino knock-downs of Unc5B and FLRT3 synergistically affect Xenopus development and induce morphogenetic defects. The small GTPase Rnd1, which transmits FLRT3 deadhesion activity, physically and functionally interacts with Unc5B, and mediates its effect on cell adhesion. The results suggest that FLRT3, Unc5B and Rnd1 proteins interact to modulate cell adhesion in early Xenopus development.
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Affiliation(s)
- Emil Karaulanov
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Ralph T. Böttcher
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Peter Stannek
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Wei Wu
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Marlene Rau
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Souichi Ogata
- Department of Developmental and Cell Biology, Developmental Biology Center, University of California Irvine, Irvine, California, United States of America
| | - Ken W. Y. Cho
- Department of Developmental and Cell Biology, Developmental Biology Center, University of California Irvine, Irvine, California, United States of America
| | - Christof Niehrs
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
- * E-mail:
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Haines BP, Rigby PWJ. Expression of the Lingo/LERN gene family during mouse embryogenesis. Gene Expr Patterns 2008; 8:79-86. [PMID: 18297755 DOI: 10.1016/j.modgep.2007.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have analysed the expression during mouse development of the four member Lingo/LERN gene family which encodes type 1 transmembrane proteins containing 12 extracellular leucine rich repeats, an immunoglobulin C2 domain and a short intracellular tail. Each family member has a distinct pattern of expression in the mouse embryo as is the case for the related NLRR, FLRT and LRRTM gene families. Lingo1/LERN1 is expressed in the developing trigeminal, facio-acoustic and dorsal root ganglia. An interesting expression pattern is also observed in the somites with expression localising to the inner surface of the dermomyotome in the ventro-caudal lip. Further expression is seen in lateral cells of the hindbrain and midbrain, lateral cells in the motor horn of the neural tube, the otic vesicle epithelium and epithelium associated with the developing gut. Lingo3/LERN2 is expressed in a broad but specific pattern in many tissues across the embryo. Lingo2/LERN3 is seen in a population of cells lying adjacent to the epithelial lining of the olfactory pit while Lingo4/LERN4 is expressed in the neural tube in a subset of progenitors adjacent to the motor neurons. Expression of all Lingo/LERN genes increases as the embryo develops but is low in the adult with only Lingo1/LERN1 and Lingo2/LERN3 being detectable in adult brain.
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Affiliation(s)
- Bryan P Haines
- The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
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Maretto S, Müller PS, Aricescu AR, Cho KWY, Bikoff EK, Robertson EJ. Ventral closure, headfold fusion and definitive endoderm migration defects in mouse embryos lacking the fibronectin leucine-rich transmembrane protein FLRT3. Dev Biol 2008; 318:184-93. [PMID: 18448090 DOI: 10.1016/j.ydbio.2008.03.021] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 03/13/2008] [Accepted: 03/14/2008] [Indexed: 12/23/2022]
Abstract
The three fibronectin leucine-rich repeat transmembrane (FLRT) proteins contain 10 leucine-rich repeats (LRR), a type III fibronectin (FN) domain, followed by the transmembrane region, and a short cytoplasmic tail. XFLRT3, a Nodal/TGFbeta target, regulates cell adhesion and modulates FGF signalling during Xenopus gastrulation. The present study describes the onset and pattern of FLRT1-3 expression in the early mouse embryo. FLRT3 expression is activated in the anterior visceral endoderm (AVE), and during gastrulation appears in anterior streak derivatives namely the node, notochord and the emerging definitive endoderm. To explore FLRT3 function we generated a null allele via gene targeting. Early Nodal activities required for anterior-posterior (A-P) patterning, primitive streak formation and left-right (L-R) axis determination were unperturbed. However, FLRT3 mutant embryos display defects in headfold fusion, definitive endoderm migration and a failure of the lateral edges of the ventral body wall to fuse, leading to cardia bifida. Surprisingly, the mutation has no effect on FGF signalling. Collectively these experiments demonstrate that FLRT3 plays a key role in controlling cell adhesion and tissue morphogenesis in the developing mouse embryo.
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Affiliation(s)
- Silvia Maretto
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
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Mühlfriedel S, Kirsch F, Gruss P, Chowdhury K, Stoykova A. Novel genes differentially expressed in cortical regions during late neurogenesis. Eur J Neurosci 2007; 26:33-50. [PMID: 17614941 DOI: 10.1111/j.1460-9568.2007.05639.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Differential gene expression across the embryonic cerebral cortex is assumed to play a role in the subdivision of the cortex into distinct areas with specific morphology, physiology and function. In a search for genes that may be involved in the cortical regionalization during late neurogenesis in mouse, we performed an extensive in-situ expression analysis at embryonic day (E)16 and E18. The examined candidate genes were selected beforehand by a microarray screen by virtue of their preferential expression in the anlagen of the motor, somatosensory, visual and cingulate cortices or hippocampus. We present new information about graded or regionally enriched expression of 25 genes (nine of which are novel genes) across the mouse embryonic cortex, in progenitor cells as well as in the cortical plate. The established differential expression of most of these genes is persistent at both stages studied, suggesting that their expression is regulated by an intrinsic programme. For some of the genes, the concept of intrinsic regulation is further substantiated by the high similarity of the reported expression patterns at E16 and E18 and published data from earlier stages. Few genes with robust expression in the E16 caudal cortex showed a more restricted pattern at E18, possibly because of their response to extrinsic cues. In addition, several genes appeared to be suitable novel markers for amygdalar and diencephalic nuclei. Taken together, our findings reveal novel molecular partitions of the late mouse cortex that are in accordance with the model of a leading role of intrinsic mechanisms in cortical arealization.
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Affiliation(s)
- Sven Mühlfriedel
- Department of Molecular Cell Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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Raivich G, Makwana M. The making of successful axonal regeneration: Genes, molecules and signal transduction pathways. ACTA ACUST UNITED AC 2007; 53:287-311. [PMID: 17079020 DOI: 10.1016/j.brainresrev.2006.09.005] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 09/12/2006] [Accepted: 09/18/2006] [Indexed: 12/16/2022]
Abstract
Unlike its central counterpart, the peripheral nervous system is well known for its comparatively good potential for regeneration following nerve fiber injury. This ability is mirrored by the de novo expression or upregulation of a wide variety of molecules including transcription factors, growth-stimulating substances, cell adhesion molecules, intracellular signaling enzymes and proteins involved in regulating cell-surface cytoskeletal interactions, that promote neurite outgrowth in cultured neurons. However, their role in vivo is less known. Recent studies using neutralizing antibodies, gene inactivation and overexpression techniques have started to shed light on those endogenous molecules that play a key role in axonal outgrowth and the process of successful functional repair in the injured nervous system. The aim of the current review is to provide a summary on this rapidly growing field and the experimental techniques used to define the specific effects of candidate signaling molecules on axonal regeneration in vivo.
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Affiliation(s)
- Gennadij Raivich
- Perinatal Brain Repair Group, Department of Obstetrics and Gynaecology, University College London, 86-96 Chenies Mews, London, UK.
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Chen Y, Aulia S, Li L, Tang BL. AMIGO and friends: An emerging family of brain-enriched, neuronal growth modulating, type I transmembrane proteins with leucine-rich repeats (LRR) and cell adhesion molecule motifs. ACTA ACUST UNITED AC 2006; 51:265-74. [PMID: 16414120 DOI: 10.1016/j.brainresrev.2005.11.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 10/23/2005] [Accepted: 11/22/2005] [Indexed: 01/17/2023]
Abstract
Leucine-rich repeats (LRR) are protein-protein interaction domains (20-29 amino acid residues in length) found in proteins with diverse structure and functions. We note here an emerging group of central nervous system-enriched, type I surface proteins with an ectodomain containing LRR repeats and motifs found in cell adhesion molecules. Members of this group include the Amphoterin-induced gene and ORF-1 (AMIGO-1), LRR and Ig domain containing Nogo Receptor interacting protein I (LINGO-1) and the netrin-G1 ligand NGL-1. The above proteins carry, in addition to the LRR repeats, an immunoglobin (Ig)-like segment in their ectodomain. Two other related families of molecules, the NLRRs and the FLRTs, have in addition, a fibronectin type III repeat. The LRR domain distinguishes these molecules from the more extensively studied Ig-like family of cell adhesion molecules, and the transmembrane domain differentiate them from the family of secreted extracellular proteoglycans with LRRs. Functionally, many members of this group of proteins could modulate neurite outgrowth of neurons, at least in vitro. LINGO-1, initially discovered as a component of the Nogo-66 receptor complex which inhibits neurite growth, also regulates oligodendrocyte differentiation and myelination. Current knowledge and recent findings pertaining to the functions of this interesting group of proteins in the nervous system are discussed.
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Affiliation(s)
- Yanan Chen
- Department of Biochemistry and Programme in Neurobiology and Aging, National University of Singapore, Singapore
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38
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Haines BP, Rigby PWJ. Developmentally regulated expression of the LRRTM gene family during mid-gestation mouse embryogenesis. Gene Expr Patterns 2006; 7:23-9. [PMID: 16860615 DOI: 10.1016/j.modgep.2006.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Revised: 05/10/2006] [Accepted: 05/11/2006] [Indexed: 12/21/2022]
Abstract
We have analysed the expression during mid-gestation mouse development of the four member LRRTM gene family which encodes type 1 transmembrane proteins containing 10 extracellular leucine rich repeats and a short intracellular tail. Each family member has a developmentally regulated pattern of expression distinct from all other members. LRRTM1 is expressed in the neural tube, otic vesicle, apical ectodermal ridge, forebrain and midbrain up to a sharp central boundary. LRRTM2 is expressed in a subset of progenitors in the neural tube. LRRTM3 is expressed in a half somite wide stripe in the presomitic mesoderm adjacent to the boundary with the most recently formed somite. Additional expression is seen in the neural tube, forebrain and hindbrain. LRRTM4 is expressed in the limb mesenchyme, neural tube, caudal mesoderm and in three distinct regions of the head. Later expression occurs in a subset of the developing sclerotome. Each family member has a unique expression domain within the neural tube.
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Affiliation(s)
- Bryan P Haines
- Section of Gene Function and Regulation, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
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Jukkola T, Lahti L, Naserke T, Wurst W, Partanen J. FGF regulated gene-expression and neuronal differentiation in the developing midbrain-hindbrain region. Dev Biol 2006; 297:141-57. [PMID: 16782087 DOI: 10.1016/j.ydbio.2006.05.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Revised: 04/03/2006] [Accepted: 05/03/2006] [Indexed: 11/23/2022]
Abstract
The neuroectodermal tissue close to the midbrain-hindbrain boundary (MHB) is an important secondary organizer in the developing neural tube. This so-called isthmic organizer (IsO) secretes signaling molecules, such as fibroblast growth factors (FGFs), which regulate cellular survival, patterning and proliferation in the midbrain and rhombomere 1 (R1) of the hindbrain. We have previously shown that FGF-receptor 1 (FGFR1) is required for the normal development of this brain region in the mouse embryo. Here, we have compared the gene expression profiles of midbrain-R1 tissues from wild-type embryos and conditional Fgfr1 mutants, in which FGFR1 is inactivated in the midbrain and R1. Loss of Fgfr1 results in the downregulation of several genes expressed close to the midbrain-hindbrain boundary and in the disappearance of gene expression gradients in the midbrain and anterior hindbrain. Our screen identified several previously uncharacterized genes which may participate in the development of midbrain-R1 region. Our results also show altered neurogenesis in the midbrain and R1 of the Fgfr1 mutants. Interestingly, the neuronal progenitors in midbrain and R1 show different responses to the loss of signaling through FGFR1.
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Affiliation(s)
- Tomi Jukkola
- Institute of Biotechnology, Viikki Biocenter, P.O. Box 56, 00014 University of Helsinki, Finland
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Haines BP, Wheldon LM, Summerbell D, Heath JK, Rigby PWJ. Regulated expression of FLRT genes implies a functional role in the regulation of FGF signalling during mouse development. Dev Biol 2006; 297:14-25. [PMID: 16872596 DOI: 10.1016/j.ydbio.2006.04.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 04/03/2006] [Accepted: 04/04/2006] [Indexed: 12/21/2022]
Abstract
Within the mammalian genome, there are many multimember gene families that encode membrane proteins with extracellular leucine rich repeats which are thought to act as cell adhesion or signalling molecules. We previously showed that the members of the NLRR gene family are expressed in a developmentally restricted manner in the mouse with NLRR-1 being expressed in the developing myotome. The FLRT gene family shows a similar genomic layout and predicted protein secondary structure to the NLRRs so we analysed expression of the three FLRT genes during mouse development. FLRTs are glycosylated membrane proteins expressed at the cell surface which localise in a homophilic manner to cell-cell contacts expressing the focal adhesion marker vinculin. Each member of the FLRT family has a distinct, highly regulated expression pattern, as was seen for the NLRR family. FLRT3 has a provocative expression pattern during somite development being expressed in regions of the somite where muscle precursor cells migrate from the dermomyotome and move into the myotome, and later in myotomal precursors destined to migrate towards their final destination, for example, those that form the ventral body wall. FLRT3 is also expressed at the midbrain/hindbrain boundary and in the apical ectodermal ridge, regions where FGF signalling is known to be important, suggesting that the role for FLRT3 in FGF signalling identified in Xenopus is conserved in mammals. FLRT1 is expressed at brain compartmental boundaries and FLRT2 is expressed in a subset of the sclerotome, adjacent to the region that forms the syndetome, suggesting that interaction with FGF signalling may be a general property of FLRT proteins. We confirmed this by showing that all FLRTs can interact with FGFR1 and FLRTs can be induced by the activation of FGF signalling by FGF-2. We conclude that FLRT proteins act as regulators of FGF signalling, being induced by the signal and then able to interact with the signalling receptor, in many tissues during mouse embryogenesis. This process may, in part, be dependent on homophilic intercellular interactions between FLRT molecules.
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Affiliation(s)
- Bryan P Haines
- Section of Gene Function and Regulation, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
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Karaulanov EE, Böttcher RT, Niehrs C. A role for fibronectin-leucine-rich transmembrane cell-surface proteins in homotypic cell adhesion. EMBO Rep 2006; 7:283-90. [PMID: 16440004 PMCID: PMC1456895 DOI: 10.1038/sj.embor.7400614] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Revised: 10/14/2005] [Accepted: 11/23/2005] [Indexed: 01/20/2023] Open
Abstract
The fibronectin-leucine-rich transmembrane (FLRT) family of leucine-rich repeat (LRR) proteins is implicated in fibroblast growth factor (FGF) signalling, early embryonic development and neurite outgrowth. Here, we have analysed whether FLRTs may also function in cell adhesion. We find that FLRT proteins can physically interact and that FLRT-transfected cultured cells sort out from non-transfected cells, suggesting a change in adhesive properties. A similar sorting effect is also observed in Xenopus embryos and tissue aggregates. FLRT-mediated cell sorting is calcium dependent and substrate independent. Deletion analysis indicates that cell sorting requires the LRR domains, which are dispensable for FLRT-mediated FGF signalling. Conversely, sorting is independent of the cytoplasmic domain, which is essential for FLRT-induced signalling. Therefore, FLRT-mediated FGF signal transduction and homotypic cell sorting can be molecularly uncoupled. The results indicate that FLRT proteins have a dual role, promoting FGF signalling and modulating homotypic cell adhesion.
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Affiliation(s)
- Emil E Karaulanov
- Division of Molecular Embryology, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ralph T Böttcher
- Division of Molecular Embryology, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Christof Niehrs
- Division of Molecular Embryology, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Tel: +49 6221 42 4690; Fax: +49 6221 42 4692; E-mail:
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