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1.
Mediators Inflamm ; 2016: 1346390, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27990061

RESUMO

The cytokine erythropoietin (EPO) stimulates proliferation and differentiation of erythroid progenitor cells. Moreover, EPO has neuroprotective, anti-inflammatory, and antioxidative effects, but the use of EPO as a neuroprotective agent is hampered by its erythropoietic activity. We have recently designed the synthetic, dendrimeric peptide, Epobis, derived from the sequence of human EPO. This peptide binds the EPO receptor and promotes neuritogenesis and neuronal cell survival. Here we demonstrate that Epobis in vitro promotes neuritogenesis in primary motoneurons and has anti-inflammatory effects as demonstrated by its ability to decrease TNF release from activated AMJ2-C8 macrophages and rat primary microglia. When administered systemically Epobis is detectable in both plasma and cerebrospinal fluid, demonstrating that the peptide crosses the blood-brain barrier. Importantly, Epobis is not erythropoietic, but systemic administration of Epobis in rats delays the clinical signs of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis, and the peptide has long-term, but not short-term, effects on working memory, detected as an improved social memory 3 days after administration. These data reveal Epobis to be a nonerythropoietic and neuroprotective EPO receptor agonist with anti-inflammatory and memory enhancing properties.


Assuntos
Peptídeos/química , Peptídeos/farmacologia , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Células Cultivadas , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/tratamento farmacológico , Eritropoetina/química , Feminino , Hematopoese/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Microglia/citologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Neurônios Motores/citologia , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Neuritos/efeitos dos fármacos , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Peptídeos/uso terapêutico , Ratos , Ratos Wistar
2.
Prog Brain Res ; 214: 353-88, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25410365

RESUMO

Extracellular matrix (ECM) molecules, their receptors at the cell surface, and cell adhesion molecules (CAMs) involved in cell-cell or cell-ECM interactions are implicated in processes related to major diseases of the central nervous system including Alzheimer's disease (AD), epilepsy, schizophrenia, addiction, multiple sclerosis, Parkinson's disease, and cancer. There are multiple strategies for targeting the ECM molecules and their metabolizing enzymes and receptors with antibodies, peptides, glycosaminoglycans, and other natural and synthetic compounds. ECM-targeting treatments include chondroitinase ABC, heparin/heparan sulfate-mimicking oligosaccharides, ECM cross-linking antibodies, and drugs stimulating expression of ECM molecules. The amount or activity of ECM-degrading enzymes like matrix metalloproteinases can be modulated indirectly via the regulation of endogenous inhibitors like TIMPs and RECK or at the transcriptional and translational levels using, e.g., histone deacetylase inhibitors, synthetic inhibitors like Periostat, microRNA-interfering drugs like AC1MMYR2, and natural compounds like flavonoids, epigallocatechin-3-gallate, anacardic acid, and erythropoietin. Among drugs targeting the major ECM receptors, integrins, are the anticancer peptide cilengitide and anti-integrin antibodies, which have a potential for treatment of stroke, multiple sclerosis, and AD. The latter can be also potentially treated with modulators of CAMs, such as peptide mimetics derived from L1-CAM and NCAM1.


Assuntos
Doenças do Sistema Nervoso Central/metabolismo , Doenças do Sistema Nervoso Central/terapia , Matriz Extracelular/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Humanos
4.
Adv Neurobiol ; 8: 315-95, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25300143

RESUMO

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.


Assuntos
Sistema Nervoso/metabolismo , Moléculas de Adesão de Célula Nervosa/química , Proteínas/química , Proteínas/metabolismo , Animais , Humanos , Proteínas de Repetições Ricas em Leucina , Modelos Moleculares , Moléculas de Adesão de Célula Nervosa/genética , Moléculas de Adesão de Célula Nervosa/metabolismo , Estrutura Terciária de Proteína , Proteínas/genética
5.
BMC Cell Biol ; 15: 31, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-25078495

RESUMO

BACKGROUND: In mammalian cells, ASPL is involved in insulin-stimulated redistribution of the glucose transporter GLUT4 and assembly of the Golgi apparatus. Its putative yeast orthologue, Ubx4, is important for proteasome localization, endoplasmic reticulum-associated protein degradation (ERAD), and UV-induced degradation of RNA polymerase. RESULTS: Here, we show that ASPL is a cofactor of the hexameric ATPase complex, known as p97 or VCP in mammals and Cdc48 in yeast. In addition, ASPL interacts in vitro with NSF, another hexameric ATPase complex. ASPL localizes to the ER membrane. The central area in ASPL, containing both a SHP box and a UBX domain, is required for binding to the p97 N-domain. Knock-down of ASPL does not impair degradation of misfolded secretory proteins via the ERAD pathway. Deletion of UBX4 in yeast causes cycloheximide sensitivity, while ubx4 cdc48-3 double mutations cause proteasome mislocalization. ASPL alleviates these defects, but not the impaired ERAD. CONCLUSIONS: In conclusion, ASPL and Ubx4 are homologous proteins with only partially overlapping functions. Both interact with p97/Cdc48, but while Ubx4 is important for ERAD, ASPL appears not to share this function.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Transporte/metabolismo , Degradação Associada com o Retículo Endoplasmático , Proteínas Nucleares/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/análise , Proteínas de Transporte/análise , Proteínas de Transporte/genética , Deleção de Genes , Técnicas de Inativação de Genes , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Mutação , Proteínas Nucleares/análise , Proteínas de Fusão Oncogênica/análise , Proteínas de Fusão Oncogênica/genética , Complexo de Endopeptidases do Proteassoma/análise , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/análise , Proteínas de Saccharomyces cerevisiae/genética
6.
J Neuroinflammation ; 11: 27, 2014 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-24490798

RESUMO

BACKGROUND: Interleukin 1 (IL-1) is implicated in neuroinflammation, an essential component of neurodegeneration. We evaluated the potential anti-inflammatory effect of a novel peptide antagonist of IL-1 signaling, Ilantide. METHODS: We investigated the binding of Ilantide to IL-1 receptor type I (IL-1RI) using surface plasmon resonance, the inhibition of Il-1ß-induced activation of nuclear factor κB (NF-κB) in HEK-Blue cells that contained an IL-1ß-sensitive reporter, the secretion of TNF-α in macrophages, protection against IL-1-induced apoptosis in neonatal pancreatic islets, and the penetration of Ilantide through the blood-brain barrier using competitive enzyme-linked immunosorbent assay (ELISA). We studied the effects of the peptide on social behavior and memory in rat models of lipopolysaccharide (LPS)- and amyloid-induced neuroinflammation, respectively, and its effect in a rat model of experimental autoimmune enchephalomyelitis. RESULTS: Ilantide bound IL-1RI, inhibited the IL-1ß-induced activation of NF-κB, and inhibited the secretion of TNF-α in vitro. Ilantide protected pancreatic islets from apoptosis in vitro and reduced inflammation in an animal model of arthritis. The peptide penetrated the blood-brain barrier. It reduced the deficits in social activity and memory in LPS- and amyloid-treated animals and delayed the development of experimental autoimmune enchephalomyelitis. CONCLUSIONS: These findings indicate that Ilantide is a novel and potent IL-1RI antagonist that is able to reduce inflammatory damage in the central nervous system and pancreatic islets.


Assuntos
Anti-Inflamatórios/uso terapêutico , Artrite/tratamento farmacológico , Encefalomielite Autoimune Experimental/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Animais , Animais Recém-Nascidos , Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Artrite/induzido quimicamente , Células Cultivadas , Cerebelo/citologia , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/induzido quimicamente , Humanos , Proteína Antagonista do Receptor de Interleucina 1/química , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Lipopolissacarídeos , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Wistar , Comportamento Social , Transfecção , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo
7.
Neurobiol Dis ; 48(3): 533-45, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22842016

RESUMO

The fibroblast growth factor receptor (FGFR) plays a vital role in the development of the nervous system regulating a multitude of cellular processes. One of the interaction partners of the FGFR is the neural cell adhesion molecule (NCAM), which is known to play an important role in neuronal development, regeneration and synaptic plasticity. Thus, simultaneous activation of FGFR- and NCAM-mediated signaling pathways may be expected to affect processes underlying neurodegenerative diseases. We here report the identification of a peptide compound, Enreptin, capable of interacting with both FGFR and NCAM. We demonstrate that this dual specificity agonist induces phosphorylation of FGFR and differentiation and survival of primary neurons in vitro, and that these effects are inhibited by abrogation of both NCAM and FGFR signaling pathways. Furthermore, Enreptin crosses the blood-brain barrier after subcutaneous administration, enhances long-term memory in normal mice and ameliorates memory deficit in mice with induced brain inflammation. Moreover, Enreptin reduces cognitive impairment and neuronal death induced by Aß25-35 in a rat model of Alzheimer's disease, and reduces the mortality rate and clinical signs of experimental autoimmune encephalomyelitis in rats. Thus, Enreptin is an attractive candidate for the treatment of neurological diseases.


Assuntos
Memória/efeitos dos fármacos , Moléculas de Adesão de Célula Nervosa/agonistas , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Oligopeptídeos/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/agonistas , Animais , Comportamento Animal/efeitos dos fármacos , Encefalopatias/patologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neurônios/citologia , Ratos , Ratos Wistar , Ressonância de Plasmônio de Superfície
8.
Basic Clin Pharmacol Toxicol ; 109(3): 164-74, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21439023

RESUMO

Valproic acid (VPA) is a known teratogen. In the present study, the effects of VPA and seven VPA derivatives with different teratogenic potencies (isobutyl-, 5-methyl-, ethyl-, propyl-, butyl-, pentyl- and hexyl-4-yn-VPA) were investigated in L929 cells in vitro. Evaluated end-points included changes in cell proliferation, growth, cell cycle distribution, morphology, speed, glycogen synthase kinase-3ß (GSK-3ß) and Erk1/2 phosphorylation, and histone H3 acetylation. Changes in proliferation, growth, speed, Erk1/2 and GSK-3ß-Tyr216 phosphorylation, and H3 acetylation were significantly associated with the teratogenic potencies of the VPA derivatives. However, in contrast to changes in Erk1/2 phosphorylation and H3 acetylation, significant changes in GSK-3ß phosphorylation could only be obtained in response to prolonged incubation at high drug concentration. There was an association between changes in H3 acetylation and GSK-3ß-Tyr216 phosphorylation, whereas none of these end-points were associated with changes in Erk1/2 phosphorylation. These results suggest that the teratogenic potencies of VPA and VPA derivatives are related to effects on both Erk1/2 and histone deacetylase activities, whereas changes in GSK-3ß activity are possibly a secondary effect.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Histona Desacetilases/metabolismo , Teratogênicos/toxicidade , Ácido Valproico/análogos & derivados , Ácido Valproico/toxicidade , Acetilação , Animais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Determinação de Ponto Final , Fibroblastos/enzimologia , Fibroblastos/patologia , Citometria de Fluxo , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Histonas/metabolismo , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação
9.
Structure ; 19(2): 203-11, 2011 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-21300289

RESUMO

The ectodomain of olfactory cell adhesion molecule (OCAM/NCAM2/RNCAM) consists of five immunoglobulin (Ig) domains (IgI-V), followed by two fibronectin-type 3 (Fn3) domains (Fn3I-II). A complete structural model of the entire ectodomain of human OCAM has been assembled from crystal structures of six recombinant proteins corresponding to different regions of the ectodomain. The model is the longest experimentally based composite structural model of an entire IgCAM ectodomain. It displays an essentially linear arrangement of IgI-V, followed by bends between IgV and Fn3I and between Fn3I and Fn3II. Proteins containing IgI-IgII domains formed stable homodimers in solution and in crystals. Dimerization could be disrupted in vitro by mutations in the dimer interface region. In conjunction with the bent ectodomain conformation, which can position IgI-V parallel with the cell surface, the IgI-IgII dimerization enables OCAM-mediated trans-interactions with an intercellular distance of about 20 nm, which is consistent with that observed in synapses.


Assuntos
Fibronectinas/metabolismo , Imunoglobulinas/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Proteínas Recombinantes/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Membrana Celular/metabolismo , Cristalografia por Raios X , Dimerização , Fibronectinas/química , Fibronectinas/genética , Expressão Gênica , Humanos , Imunoglobulinas/química , Imunoglobulinas/genética , Modelos Estruturais , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Moléculas de Adesão de Célula Nervosa/química , Moléculas de Adesão de Célula Nervosa/genética , Pichia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/genética , Sinapses/metabolismo
10.
BMC Cancer ; 10: 383, 2010 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-20663132

RESUMO

BACKGROUND: The anti-epileptic drug valproic acid (VPA) has attracted attention as an anti-cancer agent. METHODS: The present study investigated effects of VPA exposure on histone deacetylase (HDAC) inhibition, cell growth, cell speed, and the degree of Erk1/2 phosphorylation in 10 cell lines (BT4C, BT4Cn, U87MG, N2a, PC12-E2, CSML0, CSML100, HeLa, L929, Swiss 3T3). RESULTS: VPA induced significant histone deacetylase (HDAC) inhibition in most of the cell lines, but the degree of inhibition was highly cell type-specific. Moreover, cell growth, motility and the degree of Erk1/2 phosphorylation were inhibited, activated, or unaffected by VPA in a cell type-specific manner. Importantly, no relationship was found between the effects of VPA on HDAC inhibition and changes in the degree of Erk1/2 phosphorylation, cell growth, or motility. In contrast, VPA-induced modulation of the MAPK pathway downstream of Ras but upstream of MEK (i.e., at the level of Raf) was important for changes in cell speed. CONCLUSIONS: These results suggest that VPA can modulate the degree of Erk1/2 phosphorylation in a manner unrelated to HDAC inhibition and emphasize that changes in the degree of Erk1/2 phosphorylation are also important for the anti-cancer properties of VPA.


Assuntos
Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Histona Desacetilases/química , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Ácido Valproico/farmacologia , Acetilação/efeitos dos fármacos , Animais , Western Blotting , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Histona Desacetilases/metabolismo , Humanos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação/efeitos dos fármacos , Ratos
13.
J Mol Biol ; 382(5): 1113-20, 2008 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-18706912

RESUMO

The crystal structure of the first immunoglobulin (Ig1) domain of neural cell adhesion molecule 2 (NCAM2/OCAM/RNCAM) is presented at a resolution of 2.7 A. NCAM2 is a member of the immunoglobulin superfamily of cell adhesion molecules (IgCAMs). In the structure, two Ig domains interact by domain swapping, as the two N-terminal beta-strands are interchanged. beta-Strand swapping at the terminal domain is the accepted mechanism of homophilic interactions amongst the cadherins, another class of CAMs, but it has not been observed within the IgCAM superfamily. Gel-filtration chromatography demonstrated the ability of NCAM2 Ig1 to form dimers in solution. Taken together, these observations suggest that beta-strand swapping could have a role in the molecular mechanism of homophilic binding for NCAM2.


Assuntos
Molécula L1 de Adesão de Célula Nervosa/química , Caderinas/química , Adesão Celular/fisiologia , Cromatografia em Gel , Cristalografia por Raios X , Dimerização , Humanos , Imunoglobulinas/química , Modelos Moleculares , Molécula L1 de Adesão de Célula Nervosa/fisiologia , Moléculas de Adesão de Célula Nervosa/química , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Soluções , Termodinâmica
14.
J Neurosci Res ; 86(10): 2201-13, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18438920

RESUMO

The brain acid-soluble protein BASP1 (CAP-23, NAP-22) belongs to the family of growth-associated proteins, which also includes GAP-43, a protein recently shown to regulate neural cell adhesion molecule (NCAM)-mediated neurite outgrowth. Here, the effects of BASP1 overexpression were investigated in PC12E2 cells and primary hippocampal neurons. BASP1 overexpression stimulated neurite outgrowth in both cell types. The effects of BASP1 and trans-homophilic NCAM interactions were additive, and BASP1-induced neurite outgrowth was not inhibited by ectopic expression of cytoplasmic NCAM domains. Furthermore, inhibition of signaling via the fibroblast growth factor receptor, Src-family nonreceptor tyrosine kinases, protein kinase C, or GSK3beta, and expression of constructs of the cytoskeletal proteins spectrin and tau inhibited NCAM- but not BASP1-induced neurite outgrowth. Expression of BASP1 mutated at the serine-5 phosphorylation site stimulated neurite outgrowth to a degree comparable to that observed in response to overexpression of wild-type BASP1, whereas expression of BASP1 mutated at the myristoylation site at glycine-1 completely abrogated the stimulatory effects of the protein on neurite outgrowth. Finally, coexpression experiments with dominant negative and wild-type versions of GAP-43 and BASP1 demonstrated that the two proteins could substitute for each other with respect to induction of NCAM-independent neurite outgrowth, whereas BASP1 was unable to replace the stimulatory effect of GAP-43 on NCAM-mediated neurite outgrowth. These observations demonstrate that BASP1 and GAP-43 have overlapping, but not identical, functions in relation to neurite outgrowth and indicate that the main function of BASP1 is to regulate the organization and morphology of the plasma membrane.


Assuntos
Hipocampo/embriologia , Hipocampo/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuritos/metabolismo , Proteínas Repressoras/metabolismo , Animais , Membrana Celular/metabolismo , Células Cultivadas , Técnicas de Cocultura , Proteína GAP-43/metabolismo , Humanos , Immunoblotting , Imuno-Histoquímica , Camundongos , Moléculas de Adesão de Célula Nervosa/metabolismo , Células PC12 , Ratos , Transdução de Sinais/fisiologia , Transfecção
15.
Neurochem Res ; 2008 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-18368488

RESUMO

Cell adhesion molecules (CAMs) constitute a large class of plasma membrane-anchored proteins that mediate attachment between neighboring cells and between cells and the surrounding extracellular matrix (ECM). However, CAMs are more than simple mediators of cell adhesion. The neural cell adhesion molecule (NCAM) is a well characterized, ubiquitously expressed CAM that is highly expressed in the nervous system. In addition to mediating cell adhesion, NCAM participates in a multitude of cellular events, including survival, migration, and differentiation of cells, outgrowth of neurites, and formation and plasticity of synapses. NCAM shares an overall sequence identity of approximately 44% with the neural cell adhesion molecule 2 (NCAM2), a protein also known as olfactory cell adhesion molecule (OCAM) and Rb-8 neural cell adhesion molecule (RNCAM), and the region-for-region sequence homology between the two proteins suggests that they are transcribed from paralogous genes. However, very little is known about the function of NCAM2, although it originally was described more than 20 years ago. In this review we summarize the known properties and functions of NCAM2 and describe some of the differences and similarities between NCAM and NCAM2.

16.
J Neurochem ; 103(4): 1396-407, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17854387

RESUMO

A combinatorial library of undecapeptides was produced and utilized for the isolation of peptide binding to the fibronectin type 3 modules (F3I-F3II) of the neural cell adhesion molecule (NCAM). The isolated peptides were sequenced and produced as dendrimers. Two of the peptides (denoted ENFIN2 and ENFIN11) were confirmed to bind to F3I-F3II of NCAM by surface plasmon resonance. The peptides induced neurite outgrowth in primary cerebellar neurons and PC12E2 cells, but had no apparent neuroprotective properties. NCAM is known to activate different intracellular pathways, including signaling through the fibroblast growth factor receptor, the Src-related non-receptor tyrosine kinase Fyn, and heterotrimeric G-proteins. Interestingly, neurite outgrowth stimulated by ENFIN2 and ENFIN11 was independent of signaling through fibroblast growth factor receptor and Fyn, but could be inhibited with pertussis toxin, an inhibitor of certain heterotrimeric G-proteins. Neurite outgrowth induced by trans-homophilic NCAM was unaffected by the peptides, whereas knockdown of NCAM completely abrogated ENFIN2- and ENFIN11-induced neuritogenesis. These observations suggest that ENFIN2 and ENFIN11 induce neurite outgrowth in an NCAM-dependent manner through G-protein-coupled signal transduction pathways. Thus, ENFIN2 and ENFIN11 may be valuable for exploring this particular type of NCAM-mediated signaling.


Assuntos
Moléculas de Adesão de Célula Nervosa/metabolismo , Neuritos/fisiologia , Peptídeos/fisiologia , Transdução de Sinais/fisiologia , Animais , Proliferação de Células , Células Cultivadas , Cerebelo/crescimento & desenvolvimento , Cerebelo/metabolismo , Cerebelo/fisiologia , Humanos , Camundongos , Moléculas de Adesão de Célula Nervosa/antagonistas & inibidores , Moléculas de Adesão de Célula Nervosa/genética , Neuritos/metabolismo , Células PC12 , Peptídeos/genética , Peptídeos/metabolismo , Ligação Proteica/fisiologia , Ratos , Ratos Wistar , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/fisiologia , Toxoides/farmacologia
17.
Neuropharmacology ; 52(3): 764-78, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17095022

RESUMO

2-n-Pentyl-4-pentynoic acid (PE-4-yn-VPA) is a derivative of the antiepileptic and mood-stabilizing drug valproic acid (VPA). PE-4-yn-VPA exists as R- and S-enantiomers, the latter being more teratogenic. PE-4-yn-VPA also possesses antiepileptic, antiproliferative, and cell-differentiating properties. Moreover, the less teratogenic enantiomer, R-PE-4-yn-VPA, was recently shown to improve learning and memory. We here present a detailed investigation of the enantioselective properties of PE-4-yn-VPA using a range of in vitro and in vivo assays including measurements of cellular growth and migration, neuronal differentiation and survival, intracellular signal transduction, synaptic plasticity and maturation, and short-term memory as determined by the social recognition test. The results show that the enantiomers of PE-4-yn-VPA largely had similar effects in vitro. However, in all in vitro experiments the more teratogenic enantiomer, S-PE-4-yn-VPA, exhibited a stronger potency than R-PE-4-yn-VPA, and only S-PE-4-yn-VPA had a detrimental effect on cell survival. Interestingly, both the R- and S-enantiomer improved learning and memory. In contrast, the beneficial effect of S-PE-4-yn-VPA on memory was lost by time, whereas the effect of R-PE-4-yn-VPA administration was longer lasting, suggesting that the beneficial effect of the S-enantiomer on memory formation may be counteracted by its detrimental effect on neuronal cell survival.


Assuntos
Anticonvulsivantes/química , Anticonvulsivantes/farmacologia , Memória de Curto Prazo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Ácido Valproico/análogos & derivados , Análise de Variância , Animais , Comportamento Animal/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura/métodos , Proteína 4 Homóloga a Disks-Large , Relação Dose-Resposta a Droga , Hipocampo/citologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Neuritos/efeitos dos fármacos , Neurônios/citologia , Ratos , Ratos Wistar , Estereoisomerismo , Sinapses/efeitos dos fármacos , Sinapses/fisiologia , Sinaptofisina/metabolismo , Fatores de Tempo , Ácido Valproico/química , Ácido Valproico/farmacologia
18.
Toxicol In Vitro ; 18(4): 511-25, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15130609

RESUMO

Screening for potential teratogenicity of 20 test compounds was performed using a computerised microscope workstation for determination of cytotoxicity, proliferation and morphology of fibroblastoid murine L929-cells. The test compounds, which were divided into four classes according to teratogenicity were: 5-bromo-2(')-deoxyuridine, 6-aminonicotinamide, acrylamide, boric acid, D-(+)-camphor, dimethadione, dimethyl phthalate, diphenhydramine, hydroxyurea, isobutyl-ethyl-valproic acid, lithium chloride, methyl mercury chloride, methotrexate, methoxyacetic acid, penicillin G, all-trans-retinoic acid, pentyl-4-yn-valproic acid, saccharin, salicylic acid and valproic acid. All compounds, with the exception of dimethadione inhibited proliferation in a linear dose-dependent manner, and there were statistically significant compound class-dependent differences between the IC(50)-values for the compounds (p<0.0374), the strongest teratogens being the most potent. Furthermore, the average efficacies (maximum relative change) for 10 parameters describing cell morphology exhibited statistically significant compound class-dependent differences (p<0.0001), the class I and II compounds exhibiting significantly lower efficacies than the class III and IV compounds (p<0.01). Thus, test compounds affected both the proliferation and morphology of L-cells in manner demonstrating a general relationship with the teratogenic potency of the compounds. However, the moderate teratogens dimethadione and lithium chloride only had minor effects on the morphology and proliferation of the cells whereas the non-teratogen diphenhydramine had effects on both proliferation and morphology comparable to the strong teratogens.


Assuntos
Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Teratogênicos/toxicidade , Testes de Toxicidade/métodos , Animais , Automação , Técnicas de Cultura de Células , Desenvolvimento Embrionário/efeitos dos fármacos , Fibroblastos , Camundongos , Sensibilidade e Especificidade
19.
Neurochem Res ; 29(11): 2015-35, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15662836

RESUMO

The neural cell adhesion molecule, NCAM, is involved in multiple cis- and trans-homophilic interactions (NCAM binding to NCAM) thereby facilitating cell-cell adhesion through the formation of zipper-like NCAM-complexes. NCAM is also involved in heterophilic interactions with a number of proteins and extracellular matrix molecules. Some of these heterophilic interactions are mutually exclusive, and some interfere with or are dependent on homophilic NCAM interactions. Furthermore, both homo- and heterophilic interactions are modulated by posttranslational modifications of NCAM. Heterophilic NCAM-interactions initiate several intracellular signal transduction pathways ultimately leading to biological responses involving cellular differentiation, proliferation, migration and survival. Both homo- and heterophilic NCAM-interactions can be mimicked by synthetic peptides, which can induce NCAM-like signalling, and in vitro and in vivo studies suggest that such NCAM mimetics may be used for the treatment of neurodegenerative disorders.


Assuntos
Moléculas de Adesão de Célula Nervosa/fisiologia , Transdução de Sinais/fisiologia , Animais , Humanos , Isomerismo , Modelos Moleculares , Moléculas de Adesão de Célula Nervosa/química , Processamento de Proteína Pós-Traducional
20.
J Neurosci Res ; 71(1): 1-6, 2003 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-12478609

RESUMO

The neural cell adhesion molecule (NCAM) stimulates neurite outgrowth by activating intracellular signaling cascades. We investigated the role of the transcriptional repressor HES-1 in NCAM-dependent neurite outgrowth by estimating neurite extension from PC12-E2 cells grown in coculture with NCAM-negative or NCAM-positive fibroblasts. PC12-E2 cells were transiently transfected with an expression plasmid encoding HES-1. We found that expression of HES-1 inhibited NCAM-dependent neurite outgrowth. Treatment with arachidonic acid (an important messenger in NCAM-dependent signaling) restored NCAM-induced neurite outgrowth inhibited by HES-1. These results suggest that HES-1 is a regulator of intracellular signal transduction stimulated by cell adhesion molecules involved in neurite outgrowth.


Assuntos
Proteínas de Homeodomínio/fisiologia , Moléculas de Adesão de Célula Nervosa/metabolismo , Neuritos/fisiologia , Animais , Ácido Araquidônico/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Técnicas de Cocultura/métodos , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Imuno-Histoquímica , Células L , Camundongos , Fatores de Crescimento Neural/metabolismo , Células PC12 , Ratos , Proteínas Recombinantes/metabolismo , Fatores de Transcrição HES-1 , Transcrição Gênica , Transfecção
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