1
|
Coppieters N, Merry S, Patel R, Highet B, Curtis MA. Polysialic acid masks neural cell adhesion molecule antigenicity. Brain Res 2018; 1710:199-208. [PMID: 30584926 DOI: 10.1016/j.brainres.2018.12.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/31/2022]
Abstract
The neural cell adhesion molecule (NCAM) is a transmembrane protein involved in major cellular processes. The addition of polysialic acid (PSA), a post-translational modification (PTM) almost exclusively carried by NCAM, alters NCAM properties and functions and is therefore tightly regulated. Changes in NCAM and PSA-NCAM take place during development and ageing and occur in various diseases. The presence of PTMs can reduce the accessibility of antibodies to their epitopes and lead to false negative results. Thus, it is vital to identify antibodies that can specifically detect their target regardless of the presence of PTMs. In the present study, four commercially available NCAM antibodies were characterized by western blot and immunocytochemistry. Antibody specificity was determined by decreasing NCAM expression with small interfering RNA and subsequently determining whether the antibodies still produced a signal. In addition, PSA was digested with endoneuraminidase N to assess whether removing PSA improves NCAM detection with these antibodies. Our study revealed that the presence of PSA on NCAM reduced antibody accessibility to the epitope and consequently masked NCAM antigenicity for both techniques investigated. Moreover, three of the four antibodies tested were specific for the detection of NCAM by western blot and by immunocytochemistry. Altogether, this study demonstrates the importance of choosing the correct antibody to study NCAM depending on the technique of interest and underlines the importance of taking PTMs into account when using antibody-based techniques for the study of NCAM.
Collapse
Affiliation(s)
- Natacha Coppieters
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sonya Merry
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Rachna Patel
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Blake Highet
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
| |
Collapse
|
2
|
Jaako K, Waniek A, Parik K, Klimaviciusa L, Aonurm-Helm A, Noortoots A, Anier K, Van Elzen R, Gérard M, Lambeir AM, Roßner S, Morawski M, Zharkovsky A. Prolyl endopeptidase is involved in the degradation of neural cell adhesion molecules in vitro. J Cell Sci 2016; 129:3792-3802. [PMID: 27566163 DOI: 10.1242/jcs.181891] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 08/18/2016] [Indexed: 12/14/2022] Open
Abstract
Membrane-associated glycoprotein neural cell adhesion molecule (NCAM) and its polysialylated form (PSA-NCAM) play an important role in brain plasticity by regulating cell-cell interactions. Here, we demonstrate that the cytosolic serine protease prolyl endopeptidase (PREP) is able to regulate NCAM and PSA-NCAM. Using a SH-SY5Y neuroblastoma cell line with stable overexpression of PREP, we found a remarkable loss of PSA-NCAM, reduced levels of NCAM180 and NCAM140 protein species, and a significant increase in the NCAM immunoreactive band migrating at an apparent molecular weight of 120 kDa in PREP-overexpressing cells. Moreover, increased levels of NCAM fragments were found in the concentrated medium derived from PREP-overexpressing cells. PREP overexpression selectively induced an activation of matrix metalloproteinase-9 (MMP-9), which could be involved in the observed degradation of NCAM, as MMP-9 neutralization reduced the levels of NCAM fragments in cell culture medium. We propose that increased PREP levels promote epidermal growth factor receptor (EGFR) signaling, which in turn activates MMP-9. In conclusion, our findings provide evidence for newly-discovered roles for PREP in mechanisms regulating cellular plasticity through NCAM and PSA-NCAM.
Collapse
Affiliation(s)
- Külli Jaako
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| | - Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig 04103, Germany
| | - Keiti Parik
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| | - Linda Klimaviciusa
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| | - Anu Aonurm-Helm
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| | - Aveli Noortoots
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| | - Kaili Anier
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| | - Roos Van Elzen
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp B-2610, Belgium
| | - Melanie Gérard
- Interdisciplinary Research Centre KU Leuven-Kortrijk, Kortrijk B-8500, Belgium
| | - Anne-Marie Lambeir
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp B-2610, Belgium
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig 04103, Germany
| | - Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig 04103, Germany
| | - Alexander Zharkovsky
- Department of Pharmacology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu 50411, Estonia
| |
Collapse
|
3
|
Neely BA, Soper JL, Gulland FMD, Bell PD, Kindy M, Arthur JM, Janech MG. Proteomic analysis of cerebrospinal fluid in California sea lions (Zalophus californianus) with domoic acid toxicosis identifies proteins associated with neurodegeneration. Proteomics 2015; 15:4051-63. [DOI: 10.1002/pmic.201500167] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/10/2015] [Accepted: 09/09/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Benjamin A. Neely
- Department of Medicine; Division of Nephrology; Medical University of South Carolina; Charleston SC USA
| | | | | | - P. Darwin Bell
- Department of Medicine; Division of Nephrology; Medical University of South Carolina; Charleston SC USA
| | - Mark Kindy
- Marine Biomedicine and Environmental Sciences Center; Medical University of South Carolina; Charleston SC USA
- Department of Regenerative Medicine and Cell Biology; Medical University of South Carolina; Charleston SC USA
- Department of Veterans’ Affairs; Research Service; Charleston SC USA
| | - John M. Arthur
- Department of Internal Medicine; Division of Nephrology; University of Arkansas for Medical Sciences; Little Rock AR USA
| | - Michael G. Janech
- Department of Medicine; Division of Nephrology; Medical University of South Carolina; Charleston SC USA
- Marine Biomedicine and Environmental Sciences Center; Medical University of South Carolina; Charleston SC USA
| |
Collapse
|
4
|
Charfi C, Levros LC, Edouard E, Rassart E. Characterization and identification of PARM-1 as a new potential oncogene. Mol Cancer 2013; 12:84. [PMID: 23902727 PMCID: PMC3750824 DOI: 10.1186/1476-4598-12-84] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/25/2013] [Indexed: 11/21/2022] Open
Abstract
Background The Graffi murine retrovirus is a powerful tool to find leukemia associated oncogenes. Using DNA microarrays, we recently identified several genes specifically deregulated in T- and B-leukemias induced by this virus. Results In the present study, probsets associated with T-CD8+ leukemias were analyzed and we validated the expression profile of the Parm-1 gene. PARM-1 is a member of the mucin family. We showed that human PARM-1 is an intact secreted protein accumulating predominantly, such as murine PARM-1, at the Golgi and in the early and late endosomes. PARM-1 colocalization with α-tubulin suggests that its trafficking within the cell involves the microtubule cytoskeleton. Also, the protein co-localizes with caveolin-1 which probably mediates its internalization. Transient transfection of both mouse and human Parm-1 cDNAs conferred anchorage- and serum-independent growth and enhanced cell proliferation. Moreover, deletion mutants of human PARM-1 without either extracellular or cytoplasmic portions seem to retain the ability to induce anchorage-independent growth of NIH/3T3 cells. In addition, PARM-1 increases ERK1/2, but more importantly AKT and STAT3 phosphorylation. Conclusions Our results strongly suggest the oncogenic potential of PARM-1.
Collapse
Affiliation(s)
- Cyndia Charfi
- Laboratoire de Biologie Moléculaire, Département des Sciences Biologiques, Centre BioMed, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-ville, Montréal, QC H3C-3P8, Canada
| | | | | | | |
Collapse
|
5
|
Gnanapavan S, Ho P, Heywood W, Jackson S, Grant D, Rantell K, Keir G, Mills K, Steinman L, Giovannoni G. Progression in multiple sclerosis is associated with low endogenous NCAM. J Neurochem 2013; 125:766-73. [PMID: 23495921 PMCID: PMC4298029 DOI: 10.1111/jnc.12236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Revised: 03/10/2013] [Accepted: 03/11/2013] [Indexed: 12/14/2022]
Abstract
Multiple sclerosis (MS) is a CNS disorder characterized by demyelination and neurodegeneration. Although hallmarks of recovery (remyelination and repair) have been documented in early MS, the regenerative capacity of the adult CNS per se remains uncertain with the wide held belief that it is either limited or non-existent. The neural cell adhesion molecule (NCAM) is a cell adhesion molecule that has been widely implicated in axonal outgrowth, guidance and fasciculation. Here, we used in vitro and in vivo of MS to investigate the role of NCAM in disease progression. We show that in health NCAM levels decrease over time, but this occurs acutely after demyelination and remains reduced in chronic disease. Our findings suggest that depletion of NCAM is one of the factors associated with or possibly responsible for disease progression in MS.
Collapse
|
6
|
Mao X, Schwend T, Conrad GW. Expression and localization of neural cell adhesion molecule and polysialic acid during chick corneal development. Invest Ophthalmol Vis Sci 2012; 53:1234-43. [PMID: 22281821 DOI: 10.1167/iovs.11-8834] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To assay for expression and localization of neural cell adhesion molecule (NCAM) and polysialic acid (polySia) in the chick cornea during embryonic and postnatal development. METHODS Real time quantitative PCR and Western blot analyses were used to determine NCAM expression and polysiaylation in embryonic, hatchling, and adult chick corneas. Immunofluorescence staining for NCAM and polySia was conducted on cryosections of embryonic and adult corneas, whole embryonic corneas, and trigeminal neurons. RESULTS NCAM and ST8SiaII mRNA transcripts peaked by embryonic day (E)9, remained steady between E10 and E14 and slowly decreased thereafter during embryonic development. Both gene transcripts showed > 190-fold decline in the adult chick cornea compared with E9. In contrast, ST8SiaIV expression gradually decreased 26.5-fold from E6 to E19, increased thereafter, and rose to the early embryonic level in the adult cornea. Western blot analysis revealed NCAM was polysialylated and its expression developmentally changed. Other polysiaylated proteins aside from NCAM were also detected by Western blot analysis. Five NCAM isoforms including NCAM-120, NCAM-180 and three soluble NCAM isoforms with low molecular weights (87-96 kDa) were present in chick corneas, with NCAM-120 being the predominate isoform. NCAM was localized to the epithelium, stroma, and stromal extracellular matrix (ECM) of the embryonic cornea. In stroma, NCAM expression shifted from anterior to posterior stroma during embryonic development and eventually became undetectable in 20-week-old adult cornea. Additionally, both NCAM and polySia were detected on embryonic corneal and pericorneal nerves. CONCLUSIONS NCAM and polySia are expressed and developmentally regulated in chick corneas. Both membrane-associated and soluble NCAM isoforms are expressed in chick corneas. The distributions of NCAM and polySia in cornea and on corneal nerves suggest their potential functions in corneal innervation.
Collapse
Affiliation(s)
- Xiuli Mao
- Division of Biology, Kansas State University, Manhattan, Kansas 66506-4901, USA.
| | | | | |
Collapse
|
7
|
Wang W, Wang L, Luo J, Xi Z, Wang X, Chen G, Chu L. Role of a neural cell adhesion molecule found in cerebrospinal fluid as a potential biomarker for epilepsy. Neurochem Res 2012; 37:819-25. [PMID: 22219127 DOI: 10.1007/s11064-011-0677-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 12/06/2011] [Accepted: 12/15/2011] [Indexed: 12/31/2022]
Abstract
The neural cell adhesion molecule (NCAM-1) plays an important role in cell adhesion and synaptic plasticity. We designed this study to evaluate NCAM-1 as a potential biomarker for epilepsy. We performed a quantitative evaluation of the levels of NCAM-1 in cerebrospinal fluid (CSF) and serum and noted differences in patients with epilepsy compared to control subjects. We used sandwich enzyme-linked immunosorbent assays to measure NCAM-1 concentrations in CSF and serum samples of 76 epileptic patients (subdivided into the following subgroups: drug-refractory epilepsy, DRE; first-diagnosis epilepsy, FDE; and drug-effective epilepsy, DEE) and 44 control subjects. Our results show that cerebrospinal fluid-NCAM-1 (CSF-NCAM-1) concentrations and NCAM-1 Indices in the epileptic group were lower than in the control group. Both the CSF-NCAM-1 concentration and the NCAM-1 Indices in the drug-refractory epilepsy group were lower than in the drug-effective epilepsy group. These differences were statistically significant (P < 0.05). However, serum-NCAM-1 levels were not statistically different when comparing the epilepsy group to the control group (P > 0.05). Our results indicate that CSF-NCAM-1 is a potential biomarker for drug-effective epilepsy and drug-refractory epilepsy.
Collapse
Affiliation(s)
- Wei Wang
- Department of Neurology, The Affiliated Hospital of Guiyang Medical College, 28 Gui Yi Street, Guiyang, 550004 Guizhou Province, China
| | | | | | | | | | | | | |
Collapse
|
8
|
|
9
|
Affiliation(s)
- Thomas Secher
- Protein Laboratory, Institute of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark,
| |
Collapse
|
10
|
Brennaman LH, Maness PF. Developmental regulation of GABAergic interneuron branching and synaptic development in the prefrontal cortex by soluble neural cell adhesion molecule. Mol Cell Neurosci 2008; 37:781-93. [PMID: 18289872 DOI: 10.1016/j.mcn.2008.01.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 12/17/2007] [Accepted: 01/04/2008] [Indexed: 11/24/2022] Open
Abstract
Neural cell adhesion molecule, NCAM, is an important regulator of neuronal process outgrowth and synaptic plasticity. Transgenic mice that overexpress the soluble NCAM extracellular domain (NCAM-EC) have reduced GABAergic inhibitory and excitatory synapses, and altered behavioral phenotypes. Here, we examined the role of dysregulated NCAM shedding, modeled by overexpression of NCAM-EC, on development of GABAergic basket interneurons in the prefrontal cortex. NCAM-EC overexpression disrupted arborization of basket cells during the major period of axon/dendrite growth, resulting in decreased numbers of GAD65- and synaptophysin-positive perisomatic synapses. NCAM-EC transgenic protein interfered with interneuron branching during early postnatal stages when endogenous polysialylated (PSA) NCAM was converted to non-PSA isoforms. In cortical neuron cultures, soluble NCAM-EC acted as a dominant inhibitor of NCAM-dependent neurite branching and outgrowth. These findings suggested that excess soluble NCAM-EC reduces perisomatic innervation of cortical neurons by perturbing axonal/dendritic branching during cortical development.
Collapse
Affiliation(s)
- Leann Hinkle Brennaman
- Department of Biochemistry and Biophysics, and Silvio Conte Center for Schizophrenia Research, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | | |
Collapse
|
11
|
Kalus I, Bormann U, Mzoughi M, Schachner M, Kleene R. Proteolytic cleavage of the neural cell adhesion molecule by ADAM17/TACE is involved in neurite outgrowth. J Neurochem 2006; 98:78-88. [PMID: 16805798 DOI: 10.1111/j.1471-4159.2006.03847.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The transmembrane and multidomain neural cell adhesion molecule (NCAM) plays important functional roles in the developing and adult nervous system. NCAM is proteolytically processed and appears in soluble forms in the cerebrospinal fluid and in serum under normal and pathological conditions. In this report, we present evidence that the metalloprotease a disintegrin and a metalloprotease (ADAM)17/tumour necrosis factor alpha converting enzyme (TACE) cleaves the polysialylated as well as the non-polysialylated transmembrane isoforms of NCAM, whereas the glycophosphatidylinositol-linked isoform of NCAM is not proteolytically cleaved. A truncated, enzymatically inactive mutant of TACE did not result in release of the NCAM110 cleavage product. Proteolytic cleavage was enhanced by a calmodulin-specific inhibitor and the actin-destabilizing agents cytochalasin D and latrunculin B. In contrast, the microtubule-stabilizing agent colchicine or microtubule-destabilizing agent paclitaxel did not affect the release of the 110-kDa fragment of NCAM. Neurite outgrowth from cerebellar microexplants was inhibited in the presence of the metalloprotease inhibitor GM 6001 on substrate-coated NCAM, but not on poly-l-lysine. Upon transfection of hippocampal neurones with an enzymatically inactive mutant of TACE, NCAM-stimulated neurite outgrowth was inhibited without affecting neurite outgrowth on poly-l-lysine, showing that proteolytic processing of NCAM by the metalloprotease TACE is involved in NCAM-mediated neurite outgrowth.
Collapse
Affiliation(s)
- Ina Kalus
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Hamburg, Germany
| | | | | | | | | |
Collapse
|
12
|
Strekalova H, Buhmann C, Kleene R, Eggers C, Saffell J, Hemperly J, Weiller C, Müller-Thomsen T, Schachner M. Elevated levels of neural recognition molecule L1 in the cerebrospinal fluid of patients with Alzheimer disease and other dementia syndromes. Neurobiol Aging 2006; 27:1-9. [PMID: 16298234 DOI: 10.1016/j.neurobiolaging.2004.11.013] [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: 06/09/2004] [Revised: 10/26/2004] [Accepted: 11/18/2004] [Indexed: 11/20/2022]
Abstract
In this study we surveyed a total of 218 cerebrospinal fluid (CSF) samples from patients with different neurological diseases including Alzheimer disease, non-Alzheimer forms of dementia, other neurodegenerative diseases without dementia and normal controls to quantitate by capture ELISA the concentrations of the immunoglobulin superfamily adhesion molecules L1 and NCAM, and characterized by immunoblot analysis the molecular forms of L1 and NCAM. We found a significant increase of L1 and a strong tendency for increase of the soluble fragments of NCAM in the CSF of Alzheimer patients compared to the normal control group. The proteolytic fragments of L1, but not NCAM were also elevated in patients with vascular dementia and dementia of mixed type. Higher L1 concentrations were observed irrespective of age and gender. NCAM concentrations were independent of gender, but positively correlated with age and, surprisingly, also with incidence of multiple sclerosis. Thus, there was an influence of Alzheimer and non-Alzheimer dementias and neurodegeneration on L1, whereas age and neurodegeneration influenced NCAM concentrations. These observations point to an abnormal processing and/or shedding of L1 and NCAM in dementia-related neurodegeneration and age, respectively, reflecting changes in adhesion molecule-related cell interactions.
Collapse
Affiliation(s)
- Helen Strekalova
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Martinistr. 52, D 20246 Hamburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Hinkle CL, Diestel S, Lieberman J, Maness PF. Metalloprotease-induced ectodomain shedding of neural cell adhesion molecule (NCAM). ACTA ACUST UNITED AC 2006; 66:1378-95. [PMID: 16967505 DOI: 10.1002/neu.20257] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Transmembrane forms of neural cell adhesion molecule (NCAM140, NCAM180(1)) are key regulators of neuronal development. The extracellular domain of NCAM can occur as a soluble protein in normal brain, and its levels are elevated in neuropsychiatric disorders, such as schizophrenia; however the mechanism of ectodomain release is obscure. Ectodomain shedding of NCAM140, releasing a fragment of 115 kD, was found to be induced in NCAM-transfected L-fibroblasts by the tyrosine phosphatase inhibitor pervanadate, but not phorbol esters. Pervanadate-induced shedding was mediated by a disintegrin metalloprotease (ADAM), regulated by ERK1/2 MAP kinase. In primary cortical neurons, NCAM was shed at high levels, and the metalloprotease inhibitor GM6001 significantly increased NCAM-dependent neurite branching and outgrowth. Moreover, NCAM-dependent neurite outgrowth and branching were inhibited in neurons isolated from a transgenic mouse model of NCAM shedding. These results suggest that regulated metalloprotease-induced ectodomain shedding of NCAM down-regulates neurite branching and neurite outgrowth. Thus, increased levels of soluble NCAM in schizophrenic brain have the potential to impair neuronal connectivity.
Collapse
Affiliation(s)
- C Leann Hinkle
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | | | | | | |
Collapse
|
14
|
Rønn LCB, Olsen M, Soroka V, ØStergaard S, Dissing S, Poulsen FM, Holm A, Berezin V, Bock E. Characterization of a novel NCAM ligand with a stimulatory effect on neurite outgrowth identified by screening a combinatorial peptide library. Eur J Neurosci 2002; 16:1720-30. [PMID: 12431225 DOI: 10.1046/j.1460-9568.2002.02242.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The neural cell adhesion molecule, NCAM, plays a key role in neural development and plasticity mediating cell adhesion and signal transduction. By screening a combinatorial library of synthetic peptides with NCAM purified from postnatal day 10 rat brains, we identified a nonapeptide, termed NCAM binding peptide 10 (NBP10) and showed by nuclear magnetic resonance analysis that it bound the NCAM IgI module of NCAM. NBP10 modulated cell aggregation as well as neurite outgrowth induced specifically by homophilic NCAM binding. Moreover, both monomeric and multimeric forms of NBP10 stimulated neurite outgrowth from primary hippocampal neurons. The neurite outgrowth response to NBP10 was inhibited by a number of compounds previously shown to inhibit neurite outgrowth induced by homophilic NCAM binding, including voltage-dependent calcium channel antagonists, suggesting that NBP10 induced neurite outgrowth by activating a signal transduction pathway similar to that activated by NCAM itself. Moreover, an inhibitor of intracellular calcium mobilization, TMB-8, prevented NBP10-induced neurite outgrowth suggesting that NCAM-dependent neurite outgrowth also requires mobilization of calcium from intracellular calcium stores in addition to calcium influx from extracellular sources. By single-cell calcium imaging we further demonstrated that NBP10 was capable of inducing an increase in intracellular calcium in PC12E2 cells. Thus, the NBP10 peptide is a new tool for the study of molecular mechanisms underlying NCAM-dependent signal transduction and neurite outgrowth, and could prove to be a useful modulator of regenerative processes in the peripheral and central nervous system.
Collapse
Affiliation(s)
- Lars C B Rønn
- Protein Laboratory, Institute of Molecular Pathology, Panum Institute 6.2., Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Prag S, Lepekhin EA, Kolkova K, Hartmann-Petersen R, Kawa A, Walmod PS, Belman V, Gallagher HC, Berezin V, Bock E, Pedersen N. NCAM regulates cell motility. J Cell Sci 2002; 115:283-92. [PMID: 11839780 DOI: 10.1242/jcs.115.2.283] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells independently of homophilic NCAM interactions.
Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59fyn with which NCAM-140 interacts.
Furthermore, we showed that the extracellular part of NCAM acted as a paracrine inhibitor of NCAM-negative cell locomotion through a heterophilic interaction with a cell-surface receptor. As we showed that the two N-terminal immunoglobulin modules of NCAM, which are known to bind to heparin, were responsible for this inhibition, we presume that this receptor is a heparan sulfate proteoglycan. A model for the inhibitory effect of NCAM is proposed, which involves competition between NCAM and extracellular components for the binding to membrane-associated heparan sulfate proteoglycan.
Collapse
Affiliation(s)
- Søren Prag
- Protein Laboratory, Institute of Molecular Pathology, University of Copenhagen, Denmark
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
Cell adhesion molecule proteins play a diverse role in neural development, signal transduction, structural linkages to extracellular and intracellular proteins, synaptic stabilization, neurogenesis, and learning. Three basic mRNA isoforms and potent posttranslational modifications differentially regulate these neurobiological properties of the neural cell adhesion molecule (N-CAM). Abnormal concentrations of N-CAM 105-115 kDa (cN-CAM), N-CAM variable alternative spliced exon (VASE), and N-CAM secreted exon (SEC) are related to schizophrenia and bipolar neuropsychiatric disorders. These N-CAM isoforms provide potential mechanisms for expression of multiple neurobiological alterations between controls and individuals with schizophrenia or bipolar illness. Multiple processes can trigger the dysregulation of N-CAM isoforms. Differences in neuropil volume, neuronal diameter, gray matter thickness, and ventricular size can be related to N-CAM neurobiological properties in neuropsychiatric disorders. Potential test of the N-CAM dysregulation hypothesis of neuropsychiatric disorder is whether ongoing dysregulation of N-CAM would cause cognitive impairments, increased lateral ventricle volume, and decreased hippocampal volume observed in schizophrenia and to a lesser extent in bipolar disorder. An indirect test of this theory conducted in animal experiments lend support to this N-CAM hypothesis. N-CAM dysregulation is consistent with a synaptic abnormality that could underlie the disconnection between brain regions consistent with neuroimaging reports. Synapse stability and plasticity may be part of the molecular neuropathology of these disorders.
Collapse
Affiliation(s)
- M P Vawter
- National Institute on Drug Abuse-IRP (NIDA-IRP), Addiction Research Center, Section on Development and Plasticity, Baltimore, MD 21224, USA.
| |
Collapse
|
17
|
Vawter MP, Frye MA, Hemperly JJ, VanderPutten DM, Usen N, Doherty P, Saffell JL, Issa F, Post RM, Wyatt RJ, Freed WJ. Elevated concentration of N-CAM VASE isoforms in schizophrenia. J Psychiatr Res 2000; 34:25-34. [PMID: 10696830 DOI: 10.1016/s0022-3956(99)00026-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neural cell adhesion molecule (N-CAM) is a cell recognition molecule, four major isoforms (180, 140, 120, and 105-115 kDa) of which are present in brain. N-CAM has several roles in cellular organization and CNS development. Previously we have found an elevation in CSF N-CAM 120 kDa in the CSF of patients with schizophrenia, bipolar disorder, and depression. We now report an increase in the variable alternative spliced exon (VASE), a 10 amino acid sequence inserted into the fourth N-CAM domain, in the CSF of patients with schizophrenia, but not in bipolar disorder or depression. VASE-immunoreactive (VASE-ir) bands were measured in CSF from patients with schizophrenia (n = 14), bipolar disorder I (n = 7), bipolar disorder II (n = 9), unipolar depression (n = 17) and matched controls (n = 37) by Western immunoblotting. Three VASE-ir bands were distinguished in lumbar CSF corresponding to heavy (165 kDa), medium (155 kDa) and low (140 kDa) MW. A logarithmic transformation was applied to the VASE protein units and analyzed with a MANOVA. There was a 51% and 45% increase in VASE heavy (p = 0.0008) and medium (p = 0.04) MW protein, respectively, in patients with schizophrenia as compared with normal controls. Current neuroleptic treatment in patients with schizophrenia had no effect on CSF VASE concentrations. VASE concentration correlated significantly with behavioral ratings in patients with schizophrenia but not affective disorders. Thus, VASE immunoreactivity is increased in schizophrenia but not in affective disorders. These results provide further evidence of an abnormality of N-CAM protein in chronic schizophrenia and suggest differences between schizophrenia and affective disorders in regulation of N-CAM.
Collapse
Affiliation(s)
- M P Vawter
- Cellular Neurobiology Branch, NIDA-IRP, Baltimore, MD 21224, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Skladchikova G, Ronn LC, Berezin V, Bock E. Extracellular adenosine triphosphate affects neural cell adhesion molecule (NCAM)-mediated cell adhesion and neurite outgrowth. J Neurosci Res 1999; 57:207-18. [PMID: 10398298 DOI: 10.1002/(sici)1097-4547(19990715)57:2<207::aid-jnr6>3.0.co;2-m] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The neural cell adhesion molecule (NCAM) plays an important role in synaptic plasticity in embryonic and adult brain. Recently, it has been demonstrated that NCAM is capable of binding and hydrolyzing extracellular ATP. The purpose of the present study was to evaluate the role of extracellular ATP in NCAM-mediated cellular adhesion and neurite outgrowth. We here show that extracellularly added adenosine triphosphate (ATP) and its structural analogues, adenosine-5'-O-(3-thiothiophosphate), beta, gamma-methylenadenosine-5'-triphosphate, beta, gamma-imidoadenosine-5-triphosphate, and UTP, in varying degrees inhibited aggregation of hippocampal neurons. Rat glial BT4Cn cells are unable to aggregate when grown on agar but acquire this capacity when transfected with NCAM. However, addition of extracellular ATP to NCAM-transfected BT4Cn cells inhibited aggregation. Furthermore, neurite outgrowth from hippocampal neurons in cultures allowing NCAM-homophilic interactions was inhibited by addition of extracellular nucleotides. These findings indicate that NCAM-mediated adhesion may be modulated by extracellular ATP. Moreover, extracellularly added ATP stimulated neurite outgrowth from hippocampal neurons under conditions non-permissive for NCAM-homophilic interactions, and neurite outgrowth stimulated by extracellular ATP could be inhibited by a synthetic peptide corresponding to the so-called cell adhesion molecule homology domain (CHD) of the fibroblast growth factor receptor (FGFR) and by FGFR antibodies binding to this domain. Antibodies against the fibronectin type-III homology modules of NCAM, in which a putative site for ATP binding and hydrolysis is located, also abolished the neurite outgrowth-promoting effect of ATP. The non-hydrolyzable analogues of ATP all strongly inhibited neurite outgrowth. Our results indicate that extracellular ATP may be involved in synaptic plasticity through a modulation of NCAM-mediated adhesion and neurite outgrowth.
Collapse
Affiliation(s)
- G Skladchikova
- Protein Laboratory, Institute of Molecular Pathology, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | |
Collapse
|
19
|
Little EB, Edelman GM, Cunningham BA. Palmitoylation of the cytoplasmic domain of the neural cell adhesion molecule N-CAM serves as an anchor to cellular membranes. CELL ADHESION AND COMMUNICATION 1999; 6:415-30. [PMID: 10223357 DOI: 10.3109/15419069809109150] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The neural cell adhesion molecule N-CAM is expressed at key sites during embryonic development and mediates homophilic adhesion between cells both in the embryo and in the adult. N-CAM is expressed in multiple forms and two of the major isoforms differ in their cytoplasmic domains, one (ld form) having an insert of 261 amino acids that is missing in the other (sd form). N-CAM has been previously shown to be palmitoylated, but the sites of acylation have not been localized. We show here that the cytoplasmic domain of the N-CAM became palmitoylated after transfection of a cDNA encoding N-CAM into COS-7 cells, and that this acylation occurs on the four closely spaced cysteines in the cytoplasmic domain of N-CAM. Moreover, when a cDNA encoding only the cytoplasmic domain was transfected into cells, the protein was palmitoylated and associated with membranes even though it lacked a membrane spanning segment. Site directed mutagenesis of the four cysteine residues to serines at positions 5, 11, 16, and 22 in the cytoplasmic domain (723, 729, 734, and 740 in the native protein) eliminated both the palmitoylation and association with the membrane fraction. Mutagenesis of the cysteines individually, in pairs, and in groups of three indicated that C5 is not acylated with either palmitate or oleate, but the other three cysteines are acylated to different extents. Cytoplasmic domains with single cysteine mutations localized primarily in the membrane fraction, while those with three mutations were found primarily in the cytoplasm. Proteins containing two mutated cysteines were found in both the cytoplasm and the membrane fraction with C11 and C16 having the most influence on the distribution in accord with their higher level of acylation. Mutation of the cysteines did not affect the ability of full-length N-CAM to promote aggregation when transfected into COS-7 cells. Based on these results we suggest that the primary role of palmitoylation is to provide a second anchor in the plasma membrane to direct the protein to discrete membrane microdomains or to organize the cytoplasmic region for interaction with factors that affect signaling events resulting from N-CAM mediated adhesion.
Collapse
Affiliation(s)
- E B Little
- Department of Neurobiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | |
Collapse
|
20
|
van Kammen DP, Poltorak M, Kelley ME, Yao JK, Gurklis JA, Peters JL, Hemperly JJ, Wright RD, Freed WJ. Further studies of elevated cerebrospinal fluid neuronal cell adhesion molecule in schizophrenia. Biol Psychiatry 1998; 43:680-6. [PMID: 9583002 DOI: 10.1016/s0006-3223(97)00324-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The purposes of the present study were to attempt to replicate a previous finding of increased cerebrospinal fluid (CSF) neuronal cell adhesion molecule (N-CAM) in schizophrenia, and to assess whether the increases could be related to medication, clinical state effects, or brain structural measures. METHODS CSF N-CAM was measured by the Western blot technique in 45 DSM-III-R diagnosed male schizophrenic patients both on and off haloperidol treatment and in 20 healthy male control subjects. RESULTS CSF N-CAM was significantly increased in schizophrenic patients, with no overlap in the ranges, when compared to controls. There were no significant effects of medication or exacerbation on CSF N-CAM. No associations with measures of brain structure were found. CONCLUSIONS Because N-CAM levels were not shown to be different on and off treatment or in exacerbated versus nonexacerbated patients, the higher levels seen in schizophrenic patients may be inherent to the disorder and possibly related to neurodevelopment.
Collapse
Affiliation(s)
- D P van Kammen
- Veterans Affairs Medical Center, Highland Drive Division, Pittsburgh, Pennsylvania 15206, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Breen KC, Coughlan CM, Hayes FD. The role of glycoproteins in neural development function, and disease. Mol Neurobiol 1998; 16:163-220. [PMID: 9588627 DOI: 10.1007/bf02740643] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Glycoproteins play key roles in the development, structuring, and subsequent functioning of the nervous system. However, the complex glycosylation process is a critical component in the biosynthesis of CNS glycoproteins that may be susceptible to the actions of toxicological agents or may be altered by genetic defects. This review will provide an outline of the complexity of this glycosylation process and of some of the key neural glycoproteins that play particular roles in neural development and in synaptic plasticity in the mature CNS. Finally, the potential of glycoproteins as targets for CNS disorders will be discussed.
Collapse
Affiliation(s)
- K C Breen
- Neurosciences Institute, Department of Pharmacology and Clinical Pharmacology, University of Dundee, Ninewells Hospital Medical School, Scotland, UK
| | | | | |
Collapse
|
22
|
Vawter MP, Cannon-Spoor HE, Hemperly JJ, Hyde TM, VanderPutten DM, Kleinman JE, Freed WJ. Abnormal expression of cell recognition molecules in schizophrenia. Exp Neurol 1998; 149:424-32. [PMID: 9500955 DOI: 10.1006/exnr.1997.6721] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Schizophrenia is a neuropsychiatric disorder of unknown etiology associated with subtle changes in brain morphology. The cell recognition molecules (CRMs) neural cell adhesion molecule (N-CAM) and L1 are involved in morphoregulatory events and numerous neurodevelopmental processes. We found a selective increase of 105- to 115-kDa N-CAM in the hippocampus and prefrontal cortex of patients with schizophrenia while other N-CAM isoforms and L1 proteins were not altered. There was also evidence for an abnormality in CRM expression in schizophrenic patients: concentrations of 200-kDa L1 were strongly correlated with expression of N-CAM isoforms and cleaved L1 proteins in controls, whereas these correlations were absent in patients with schizophrenia. The increase of the 105- to 115-kDa N-CAM isoform in the brains of patients with schizophrenia confirms previous cerebrospinal fluid findings. Increased N-CAM in schizophrenia may result from structural brain abnormalities, from glial processing of N-CAM, or from an aberration in the regulation of N-CAM expression.
Collapse
Affiliation(s)
- M P Vawter
- Section on Preclinical Neuroscience, NIMH Neuroscience Center at Saint Elizabeths, Washington, DC 20032, USA
| | | | | | | | | | | | | |
Collapse
|
23
|
Dzhandzhugazyan K, Bock E. Demonstration of an extracellular ATP-binding site in NCAM: functional implications of nucleotide binding. Biochemistry 1997; 36:15381-95. [PMID: 9398268 DOI: 10.1021/bi9709351] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A minor fraction of the total ecto-type (E-type) ATPase activity of rat synaptosomes has been detected in immunoprecipitates of the neural cell adhesion molecule, NCAM, indicating that this either is an intrinsic enzymatic activity of NCAM or of an ATPase tightly associated to NCAM [Dzhandzhugazyan & Bock (1993) FEBS Lett. 336, 279-283]. We here demonstrate ATPase activity in preparations of the lipid-anchored as well as the transmembrane NCAM isoforms immunoisolated from transfected L-cells. A fraction of the E-type ATPase activity is spontaneously released from synaptosomes. Released material was fractionated by various chromatographic procedures and an extracellular fragment of NCAM was shown to co-elute with the major part of the enzymatic activity. Furthermore, it was shown that agarose-coupled NCAM-antibodies retained 85% of the ATPase activity released from synaptosomes after treatment with phosphatidylinositol-specific phospholipase C. These findings restricted the association or expression of the enzymatic activity to the extracellular part of NCAM. An affinity reagent, 5'-p-fluorosulfonylbenzoyl adenosine, FSBA, was shown to inhibit ATPase activity of immunoisolated NCAM, and incorporation of FSBA was detected in all three major NCAM isoforms (A, B, and C). An excess of ATP prevented both inactivation of the enzyme and affinity labeling of NCAM. Thus, NCAM contains an ATP-binding site, and this site is localized extracellularly and probably has the catalytic function. Binding of the substrate or FSBA protected a proteolytic cleavage site in NCAM localized close to the membrane presumably by induction of a local conformational change in NCAM, indicating a mechanism by which ATP may regulate NCAM adhesion and adhesion-triggered processes. A possible role of this mechanism in synaptic plasticity and memory consolidation is proposed.
Collapse
Affiliation(s)
- K Dzhandzhugazyan
- Institute of Molecular Pathology, Protein Laboratory, Panum Institute, Blegdamsvej 3C, Bld. 6.2, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | | |
Collapse
|
24
|
Efthimiopoulos S, Vassilacopoulou D, Ripellino JA, Tezapsidis N, Robakis NK. Cholinergic agonists stimulate secretion of soluble full-length amyloid precursor protein in neuroendocrine cells. Proc Natl Acad Sci U S A 1996; 93:8046-50. [PMID: 8755600 PMCID: PMC38872 DOI: 10.1073/pnas.93.15.8046] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The Abeta peptide of Alzheimer disease is derived from the proteolytic processing of the amyloid precursor proteins (APP), which are considered type I transmembrane glycoproteins. Recently, however, soluble forms of full-length APP were also detected in several systems including chromaffin granules. In this report we used antisera specific for the cytoplasmic sequence of APP to show that primary bovine chromaffin cells secrete a soluble APP, termed solAPPcyt, of an apparent molecular mass of 130 kDa. This APP was oversecreted from Chinese hamster ovary cells transfected with a full-length APP cDNA indicating that solAPPcyt contained both the transmembrane and Abeta sequence. Deglycosylation of solAPPcyt showed that it contained both N- and O-linked sugars, suggesting that this APP was transported through the endoplasmic reticulum-Golgi pathway. Secretion of solAPPcyt from primary chromatin cells was temperature-, time-, and energy-dependent and was stimulated by cell depolarization in a Ca2+-dependent manner. Cholinergic receptor agonists, including acetylcholine, nicotine, or carbachol, stimulated the rapid secretion of solAPPcyt, a process that was inhibited by cholinergic antagonists. Stimulation of solAPPcyt secretion was paralleled by a stimulation of secretion in catecholamines and chromogranin A, indicating that secretion of solAPPcyt was mediated by chromaffin granule vesicles. Taken together, our results show that release of the potentially amyloidogenic solAPPcyt is an active cellular process mediated by both the constitutive and regulated pathways. solAPPcyt was also detected in human cerebrospinal fluid. Combined with the neuronal physiology of chromaffin cells, our data suggest that cholinergic agonists may stimulate the release of this APP in neuronal synapses where it may exert its biological functions. Moreover, vesicular or secreted solAPPcyt may serve as a soluble precursor of Abeta.
Collapse
Affiliation(s)
- S Efthimiopoulos
- Department of Psychiatry and Fishberg Research Center for Neurobiology, Mount Sinai School of Medicine, NY 10029, USA
| | | | | | | | | |
Collapse
|
25
|
Abstract
The Neural Cell Adhesion Molecule NCAM is a membrane glycoprotein and belongs to the immunoglobulin superfamily. It is expressed on neural cells as well as on various neuroendocrine tumors and can be detected in sera of patients with small cell lung cancer. Its role is attributed to tumor invasion and formation of metastases. Malignant plasma cells and a subset of plasma cells from patients with monoclonal gammopathy exhibit surface expression of NCAM whereas normal plasma cells do not express NCAM. Expression as measured by flow cytometry using anti-CD56 antibodies does not seem to correlate with clinical course, however leukemic myelomas and myeloma cell lines tend to loose NCAM surface expression. An isoform of NCAM which is rich in polysialic acids and characteristic for embryonal NCAM (eNCAM) has been shown to be elevated in sera of patients with multiple myeloma using a chemiluminescence immunoassay. Patients with progressive myeloma tend to have high serum NCAM levels above the normal range of 20 U/ml. Analysis of 125 myeloma patients suggest that serum NCAM is a valuable parameter for tumor progression rather than tumor mass. Increase in serum NCAM may be associated with loss of adhesive function.
Collapse
Affiliation(s)
- U Kaiser
- Zentrum Innere Medizin, Abt.Hamatologie/Onkologie, Philipps-Universitat, Research Laboratories, Behringwerke AG, Marburg, Germany
| | | | | |
Collapse
|
26
|
Roth J. Chapter 14 Polysialic acids of vertebrates: biosynthesis, structural diversity, tissue expression and functions. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0167-7306(08)60300-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
|
27
|
Jørgensen OS. Neural cell adhesion molecule (NCAM) as a quantitative marker in synaptic remodeling. Neurochem Res 1995; 20:533-47. [PMID: 7643959 DOI: 10.1007/bf01694535] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The neural cell adhesion molecule (NCAM) participates in adhesion and neuritic outgrowth during nervous system development. In the adult brain, NCAM is considered to be involved in neuronal sprouting and synaptic remodeling. The NCAM concentration of brain tissue has proved to be a useful marker of these processes, especially when viewed in comparison with the concentration of a marker of mature synapses, e.g. D3-protein (SNAP-25) or synaptophysin. The present review focusses on studies of adult brain in which NCAM concentration estimates and NCAM/D3 ratios have been used to evaluate the rate of synaptic remodeling in brain damage and degenerative diseases.
Collapse
Affiliation(s)
- O S Jørgensen
- Department of Pharmacology, University of Copenhagen, Denmark
| |
Collapse
|
28
|
Olsen M, Zuber C, Roth J, Linnemann D, Bock E. The ability to re-express polysialylated NCAM in soleus muscle after denervation is reduced in aged rats compared to young adult rats. Int J Dev Neurosci 1995; 13:97-104. [PMID: 7639100 DOI: 10.1016/0736-5748(95)00003-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The neural cell-adhesion molecule, NCAM, contains an unusual homopolymer of sialic acid units, polysialic acid. This carbohydrate seems to be involved in neurite outgrowth, bundling and branching, processes which are important during reinnervation. In aged rats, reinnervation of denervated muscle fibres is incomplete. In this study, age-related changes in the degree of polysialylation of NCAM re-expressed after denervation were examined using a monoclonal antibody recognizing polysialic acid and a polyclonal antibody recognizing NCAM. The results show that, after denervation, the degree of polysialylation on NCAM was clearly reduced in rat soleus muscle of aged, compared to young, adult rats. This age-related change in expression of polysialic acid probably influences the reinnervation process in aged muscle.
Collapse
Affiliation(s)
- M Olsen
- Research Center for Medical Biotechnology, University of Copenhagen, N. Denmark
| | | | | | | | | |
Collapse
|
29
|
Bonfanti L, Theodosis DT. Expression of polysialylated neural cell adhesion molecule by proliferating cells in the subependymal layer of the adult rat, in its rostral extension and in the olfactory bulb. Neuroscience 1994; 62:291-305. [PMID: 7816207 DOI: 10.1016/0306-4522(94)90333-6] [Citation(s) in RCA: 184] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The highly sialylated isoform of the neural cell adhesion molecule is thought to be expressed predominantly in the developing nervous system, where it is implicated in a variety of dynamic events linked to neural morphogenesis. It has become increasingly evident, however, that this "embryonic" neural cell adhesion molecule isoform continues to be expressed in certain adult neuronal systems, and in particular, in those that can undergo structural plasticity. In the present study, we performed light microscopic immunocytochemistry with an antibody specific for polysialylated neural cell adhesion molecule and confirmed our earlier observations [Bonfanti L. et al. (1992) Neuroscience 49, 419-436] showing polysialylated neural cell adhesion molecule-immunoreactive cells in the subependymal layer of the lateral ventricle of the adult rat, a region where cell proliferation continues into the postnatal period. In addition, we used an antibody raised against the proliferating cell nuclear antigen and found that proliferating cells continue to be visible in this area, even in the adult. Double immunolabeling showed that many of these newly generated cells displayed high polysialylated neural cell adhesion molecule immunoreactivity. Cells from a portion of the subependymal layer migrate to the olfactory bulb and contribute to the continual replacement of its granule neurons [Luskin M. B. (1993) Neuron 11, 173-189]. We found polysialylated neural cell adhesion molecule-immunoreactive cells all along the pathway purported to be followed by the newly generated cells to their final destination and in neurons corresponding to granular and periglomerular cells in the olfactory bulb. Our present observations thus support the contention that polysialylation is a feature of neurons capable of dynamic change and may contribute to the molecular mechanisms permitting cell proliferation and migration not only during development but also in the adult.
Collapse
Affiliation(s)
- L Bonfanti
- Dipartimento di Morfofisiologia Veterinaria, University of Turin, Italy
| | | |
Collapse
|
30
|
Mayerhofer A, Lahr G, Fröhlich U, Zienecker R, Sterzik K, Gratzl M. Expression and alternative splicing of the neural cell adhesion molecule NCAM in human granulosa cells during luteinization. FEBS Lett 1994; 346:207-12. [PMID: 8013635 DOI: 10.1016/0014-5793(94)00473-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Freshly aspirated human granulosa cells from pre-ovulatory follicles and granulosa cells luteinized in culture possess the neural cell adhesion molecule (NCAM) of approximate molecular mass of 140,000 and NCAM mRNA as confirmed by S1-nuclease protection assays and RT-PCR. Moreover, in the process of luteinization the NCAM isoform pattern is modified. Isoforms containing an insert of 10 amino acids (termed VASE) in the extracellular domain of NCAM were supplemented by alternatively spliced isoforms without this insert. NCAM immunoreactivity, at light and electron microscope levels, was associated with the cell membrane of most granulosa cells which formed clusters. During time in culture an increasing subpopulation of granulosa cells, devoid of NCAM immunoreactivity, spread out and formed monolayers. This differential expression and the alternative splicing of NCAM during luteinization of granulosa cells raise the possibility that NCAM could be involved in folliculogenesis and the formation of the corpus luteum in the human.
Collapse
Affiliation(s)
- A Mayerhofer
- Department of Anatomy, University of Ulm, Germany
| | | | | | | | | | | |
Collapse
|
31
|
Olsen M, Krog L, Edvardsen K, Skovgaard LT, Bock E. Intact transmembrane isoforms of the neural cell adhesion molecule are released from the plasma membrane. Biochem J 1993; 295 ( Pt 3):833-40. [PMID: 8240299 PMCID: PMC1134637 DOI: 10.1042/bj2950833] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Three soluble neural cell adhesion molecule (NCAM) polypeptide classes of M(r) values 190,000 (NCAM-s1), 135,000 (NCAM-s2) and 115,000-110,000 (NCAM-s3) have been demonstrated in rat brain and cerebrospinal fluid [Krog, Olsen, Dalseg, Roth and Bock (1992) J. Neurochem. 59, 838-847]. NCAM-s3 is known to arise from released glycosylphosphatidylinositol (GPI)-linked NCAM [He, Finne and Goridis (1987) J. Cell. Biol. 105, 2489-2500] as well as from extracellularly cleaved transmembrane NCAM isoforms [Nybroe, Linnemann and Bock (1989) J. Neurochem. 53, 1372-1378]. In this study the origin of NCAM-s1 and NCAM-s2 and the function of soluble NCAM forms were investigated. It was shown that all three soluble forms could be released from brain membranes with M(r) values identical to the three major membrane-associated forms: the large transmembrane 190,000-M(r) form (NCAM-A), the smaller transmembrane 135,000-M(r) form (NCAM-B) and the GPI-anchored 115,000-110,000-M(r) form (NCAM-C). A polyclonal antibody, directed against transmembrane and cytoplasmic epitopes common to NCAM-A and NCAM-B, was shown to react with NCAM-s1 and NCAM-s2. Furthermore, NCAM-B was shown to be shed in a presumably intact soluble form from membranes of cells transfected with this isoform. Thus, NCAM-s1 and NCAM-s2 probably represent intact released transmembrane NCAM-A and NCAM-B. The soluble transmembrane forms are likely to exist in vivo, as NCAM-s1 and NCAM-s2 were readily demonstrated in cerebrospinal fluid. By density-gradient centrifugation it was shown that shed transmembrane NCAM-B was present in fractions of high, as well as low, density, indicating that a fraction of the shed NCAM is associated with minor plasma membrane fragments. Finally, it was shown that isolated soluble NCAM inhibited cell binding to an immobilized NCAM substratum, attributing a pivotal role to soluble NCAM in vivo as a modulator of NCAM-mediated cell behaviour.
Collapse
Affiliation(s)
- M Olsen
- Research Centre for Medical Biotechnology, University of Copenhagen, Panum Institute, Denmark
| | | | | | | | | |
Collapse
|
32
|
Gegelashvili G, Andersson AM, Schousboe A, Bock E. Characterization of NCAM diversity in cultured neurons. FEBS Lett 1993; 324:337-40. [PMID: 8405377 DOI: 10.1016/0014-5793(93)80146-l] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A single transcript of the NCAM gene undergoes differential processing resulting in a multiplicity of mRNAs and their translation products. In this study, the diversity of NCAM in rat primary neuronal cultures was investigated utilizing immuno- and Northern blot analyses. NCAM polypeptides of 190 kDa (NCAM-A) and 135 kDa (NCAM-B) were shown to be associated with the neuronal phenotype. These data were confirmed by Northern blotting, which in both neocortical neurons and cerebellar granule neurons revealed mRNA classes of 7.4 kb and 6.7 kb encoding for NCAM-A and -B, respectively. However, oligonucleotide probes, specific for selected exons or exon combinations, revealed special features of cerebellar granule neurons as compared to neocortical neurons: expression of 4.3 kb NCAM mRNA, a relatively low amount of VASE-containing variants, and an apparent lack of mRNA species containing exons alpha and an AAG insert between exons 12 and 13. Distinct patterns of NCAM mRNA may putatively be related to the regional origin and functional specificity of the investigated neurons.
Collapse
Affiliation(s)
- G Gegelashvili
- Research Center for Medical Biotechnology, University of Copenhagen, Panum Institute, Denmark
| | | | | | | |
Collapse
|
33
|
Kärkelä J, Bock E, Kaukinen S. CSF and serum brain-specific creatine kinase isoenzyme (CK-BB), neuron-specific enolase (NSE) and neural cell adhesion molecule (NCAM) as prognostic markers for hypoxic brain injury after cardiac arrest in man. J Neurol Sci 1993; 116:100-9. [PMID: 8509798 DOI: 10.1016/0022-510x(93)90095-g] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Creatine kinase (CK) and its brain-specific isoenzyme (CK-BB), neuron-specific enolase (NSE), neural cell adhesion molecule (NCAM) and the ions sodium, potassium, chloride and calcium were measured both in CSF and serum and inorganic phosphate in CSF in order to assess their prognostic value in total brain ischemia due to cardiac arrest. The samples were collected at 4, 28 and 76 h after resuscitation. Twenty consecutive patients resuscitated from ventricular fibrillation or asystole were included in the study. Nine of the patients recovered consciousness (recovered) but eleven remained comatose (disabled). The follow-up period was 2 years after which only one patient was still alive. The earliest statistically significant differences between neurologically recovered and disabled patient groups were seen in CSF inorganic phosphate (P = 0.030) already at 4 h and CK-BB (P = 0.046) and NSE (P = 0.020) activity at 28 h. Later, at 76 h after the resuscitation CSF NSE differentiated the groups most clearly (P = 0.014). The values were higher in the disabled patients. A negative correlation between CSF parameters and Glasgow Coma scores was also seen at these timepoints. Statistically significant differences between the groups were seen in both CSF and blood pCO2, pO2, base excess (BE) and actual bicarbonate (HCO3-). CSF or serum NCAM has no prognostic value in anoxic-ischemic coma. The results suggest that in CSF CK-BB and NSE are useful prognostic indicators of hypoxic brain injury when measured 28-76 h after cardiac arrest whereas blood samples have no prognostic value.
Collapse
Affiliation(s)
- J Kärkelä
- Department of Anaesthesia, Tampere University Hospital, Finland
| | | | | |
Collapse
|
34
|
Andersson AM, Olsen M, Zhernosekov D, Gaardsvoll H, Krog L, Linnemann D, Bock E. Age-related changes in expression of the neural cell adhesion molecule in skeletal muscle: a comparative study of newborn, adult and aged rats. Biochem J 1993; 290 ( Pt 3):641-8. [PMID: 8457191 PMCID: PMC1132328 DOI: 10.1042/bj2900641] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Neural cell adhesion molecule (NCAM) is expressed by muscle and involved in muscle-neuron and muscle-muscle cell interactions. The expression in muscle is regulated during myogenesis and by the state of innervation. In aged muscle, both neurogenic and myogenic degenerative processes occur. We here report quantitative and qualitative changes in NCAM protein and mRNA forms during aging in normal rat skeletal muscle. Determination of the amount of NCAM by e.l.i.s.a. showed that the level decreased from perinatal to adult age, followed by a considerable increase in 24-month-old rat muscle. Thus NCAM concentration in aged muscle was sixfold higher than in young adult muscle. In contrast with previous reports, NCAM polypeptides of 200, 145, 125 and 120 kDa were observed by immunoblotting throughout postnatal development and aging, the relative proportions of the individual NCAM polypeptides remaining virtually unchanged at all ages examined. However, changes in the extent of sialylation of NCAM were demonstrated. Even though the relative amounts of the various NCAM polypeptides were unchanged during aging, distinct changes in NCAM mRNA classes were observed. Three NCAM mRNA classes of 6.7, 5.2 and 2.9 kb were present in perinatal and young adult skeletal muscle, whereas only the 5.2 and 2.9 kb mRNA classes could be demonstrated in aged muscle. This indicates that metabolism of the various NCAM polypeptides is individually regulated during aging. Alternative splicing of NCAM mRNA in skeletal muscle was studied by Northern blotting using DNA oligonucleotide probes specifically hybridizing to selected exons or exon combinations. Exon VASE, which has previously been shown to be present in both brain and heart NCAM mRNA, was virtually absent from skeletal muscle at all ages studied. In contrast, the majority of NCAM mRNA in postnatal skeletal muscle was shown to contain extra exons inserted between exons 12 and 13. Of the various possible exon combinations at this splice site, the combinations 12-a-AAG-13 and 12-a-b seemed to be prevalent in postnatal skeletal muscle. No significant change in the relative proportion of these two exon combinations occurred during aging. The observed upregulation of NCAM protein in aged muscle supports the assumption that an increasing proportion of muscle fibres are denervated in aged muscle. Selective upregulation of the 5.2 and 2.9 kb mRNA forms have previously been demonstrated in muscle cell lines and in primary cultures of muscle cells during formation of myotubes in vitro, and this switch in NCAM mRNA classes has been suggested to correlate with myogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- A M Andersson
- Research Centre for Medical Biotechnology, University of Copenhagen, Panum Institute, Denmark
| | | | | | | | | | | | | |
Collapse
|
35
|
Linnemann D, Gaardsvoll H, Olsen M, Bock E. Expression of NCAM mRNA and polypeptides in aging rat brain. Int J Dev Neurosci 1993; 11:71-81. [PMID: 8488756 DOI: 10.1016/0736-5748(93)90036-d] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In aging brain, degenerative as well as compensatory regenerative processes are believed to occur. The neural cell adhesion molecule NCAM is involved in developmental and regenerative processes in the brain. However, the role of NCAM in aging brain has not been characterized. In this study, the expression of NCAM mRNAs and polypeptides was investigated in aging rat brain. The 7.4 and 6.7 kb NCAM mRNAs were selectively downregulated during postnatal development, and the 5.2 and 2.9 kb NCAM mRNAs were upregulated. However, from postnatal day 40 to old age no change in NCAM mRNA classes was observed. The fraction of NCAM mRNA containing the VASE exon increased postnatally but remained stable during adult life. VASE, which is believed to modulate the binding capacity, seemed to be relatively more abundant in the 7.4 and 6.7 kb NCAM mRNAs, encoding transmembrane NCAM forms, than in the 5.2 and 2.9 kb NCAM mRNAs, coding for glycosyl phosphatidylinositol (GPI) linked NCAM. Conversely, insertion of exons a and AAG between exons 12 and 13, a region containing two fibronectin type III repeats, seemed to be more pronounced in 5.2 and 2.9 kb NCAM mRNAs than in the 7.4 and 6.7 kb mRNAs. During postnatal development an increase in the fraction of 6.7 kb NCAM mRNA containing the exons a and AAG was observed. However, during aging the fraction of NCAM mRNAs containing this exon combination seemed constant. At the protein level, NCAM-A was downregulated both during development and aging. No changes were observed during aging in the composition of soluble NCAM forms in the brain, cerebrospinal fluid or blood plasma. The amount of NCAM in rat brain decreased during postnatal development, but remained at a constant level from postnatal day 40 to old age. To conclude, several changes in NCAM expression occur during early postnatal development emphasizing the important role of this molecule in the morphogenetic processes. During aging, a significant selective downregulation of NCAM-A was observed indicating that in general only minor regenerative processes occur in the brain.
Collapse
Affiliation(s)
- D Linnemann
- Research Center for Medical Biotechnology, University of Copenhagen, Denmark
| | | | | | | |
Collapse
|