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2.
Fertil Steril ; 113(1): 176-186, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32033718

RESUMO

OBJECTIVE: To characterize the role of steroid hormone and antihormone exposure on neurotrimin (NTM) expression in human leiomyoma and myometrial tissue and cells. DESIGN: Laboratory study of placebo and ulipristal acetate (UPA)-treated patient tissue. In vitro assessment of immortalized myometrial and leiomyoma cell lines after hormone and antihormone exposure. SETTING: Academic research center. PATIENT(S): Not applicable. INTERVENTIONS(S): Exposure of leiomyoma cell lines to 17ß-E2, medroxyprogesterone acetate (MPA), UPA, and fulvestrant. MAIN OUTCOME MEASURE(S): Messenger RNA expression quantified with the use of RNASeq analysis and quantitative real-time polymerase chain reaction (qRT-PCR). Protein levels quantified by means of Western blot analysis. Immunohistochemistry (IHC) on placebo- and UPA-treated patient uterine tissue specimens. RESULT(S): Expression of NTM in human uterine leiomyoma specimens according to RNASeq was increased compared with myometrium (5.22 ± 0.57-fold), which was confirmed with the use of qRT-PCR (1.95 ± 0.05). Furthermore, NTM protein was elevated in leiomyoma tissue compared with matched myometrium (2.799 ± 0.575). IHC revealed increased staining intensity in leiomyoma surgical specimens compared with matched myometrium of placebo patients. Western blot analysis in immortalized leiomyoma cell lines demonstrated an up-regulation of NTM protein expression (2.4 ± 0.04). Treatment of leiomyoma cell lines with 17ß-E2 yielded a 1.98 ± 0.11-fold increase in NTM protein expression; however, treatment with fulvestrant showed no significant change compared with control. Leiomyoma cell lines demonstrated a 1.91 ± 0.97-fold increase in NTM protein expression after progesterone treatment. RNASeq analysis demonstrated a reduced expression in patient leiomyoma after UPA treatment (0.75 ± 0.14). Treatment of leiomyoma cells with UPA demonstrated a reduced total NTM protein amount (0.54 ± 0.31) in patients, which was confirmed with the use of IHC (UPA10 147.2 ± 9.40, UPA20 182.8 ± 8.98). In vitro studies with UPA treatment revealed a concentration-dependent effect that supported these findings. CONCLUSION(S): NTM, a neural cell adhesion molecule, is increased in leiomyoma compared with myometrium in patient tissue and in vitro models after estrogen and progesterone treatment. Down-regulation of expression occurs after UPA treatment, but not after fulvestrant exposure. CLINICAL TRIAL REGISTRATION NUMBER: NCT00290251.


Assuntos
Anticoncepcionais Femininos/farmacologia , Hormônios Esteroides Gonadais/farmacologia , Antagonistas de Hormônios/farmacologia , Leiomioma/metabolismo , Moléculas de Adesão de Célula Nervosa/biossíntese , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Anticoncepcionais Femininos/uso terapêutico , Método Duplo-Cego , Estradiol/farmacologia , Estradiol/uso terapêutico , Feminino , Proteínas Ligadas por GPI/agonistas , Proteínas Ligadas por GPI/biossíntese , Hormônios Esteroides Gonadais/uso terapêutico , Antagonistas de Hormônios/uso terapêutico , Humanos , Leiomioma/tratamento farmacológico , Leiomioma/patologia , Moléculas de Adesão de Célula Nervosa/agonistas , Norpregnadienos/farmacologia , Norpregnadienos/uso terapêutico
3.
Prostate ; 80(4): 352-364, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31905248

RESUMO

BACKGROUND: Signal regulatory protein ß1 (SIRPB1) is a signal regulatory protein member of the immunoglobulin superfamily and is capable of modulating receptor tyrosine kinase-coupled signaling. Copy number variations at the SIRPB1 locus were previously reported to associate with prostate cancer aggressiveness in patients, however, the role of SIRPB1 in prostate carcinogenesis is unknown. METHODS: Fluorescence in situ hybridization and laser-capture microdissection coupled with quantitative polymerase chain reaction was utilized to determine SIRPB1 gene amplification and messenger RNA expression in prostate cancer specimens. The effect of knockdown of SIRPB1 by RNA interference in PC3 prostate cancer cells on cell growth in colony formation assays and cell mobility in wound-healing, transwell assays, and cell cycle analysis was determined. Overexpression of SIPRB1 in C4-2 prostate cancer cells on cell migration, invasion, colony formation and cell cycle progression and tumor take rate in xenografts was also determined. Western blot assay of potential downstream SIRPB1 pathways was also performed. RESULTS: SIRPB1 gene amplification was detected in up to 37.5% of prostate cancer specimens based on in silico analysis of several publicly available datasets. SIRPB1 gene amplification and overexpression were detected in prostate cancer specimens. The knockdown of SIRPB1 significantly suppressed cell growth in colony formation assays and cell mobility. SIRPB1 knockdown also induced cell cycle arrest during the G0 /G1 phase and enhancement of apoptosis. Conversely, overexpression of SIPRB1 in C4-2 prostate cancer cells significantly enhanced cell migration, invasion, colony formation, and cell cycle progression and increased C4-2 xenograft tumor take rate in nude mice. Finally, this study presented evidence for SIRPB1 regulation of Akt phosphorylation and showed that Akt inhibition could abolish SIRPB1 stimulation of prostate cancer cell proliferation. CONCLUSIONS: These results suggest that SIRPB1 is a potential oncogene capable of activating Akt signaling to stimulate prostate cancer proliferation and could be a biomarker for patients at risk of developing aggressive prostate cancer.


Assuntos
Moléculas de Adesão de Célula Nervosa/genética , Moléculas de Adesão de Célula Nervosa/metabolismo , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Ativação Enzimática , Amplificação de Genes , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Moléculas de Adesão de Célula Nervosa/biossíntese , Células PC-3 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais
4.
Neuron ; 106(1): 108-125.e12, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-31995730

RESUMO

Presynaptic neurexins (Nrxs) and type IIa receptor-type protein tyrosine phosphatases (RPTPs) organize synapses through a network of postsynaptic ligands. We show that leucine-rich-repeat transmembrane neuronal proteins (LRRTMs) differentially engage the protein domains of Nrx but require its heparan sulfate (HS) modification to induce presynaptic differentiation. Binding to the HS of Nrx is sufficient for LRRTM3 and LRRTM4 to induce synaptogenesis. We identify mammalian Nrx1γ as a potent synapse organizer and reveal LRRTM4 as its postsynaptic ligand. Mice expressing a mutant form of LRRTM4 that cannot bind to HS show structural and functional deficits at dentate gyrus excitatory synapses. Through the HS of Nrx, LRRTMs also recruit PTPσ to induce presynaptic differentiation but function to varying degrees in its absence. PTPσ forms a robust complex with Nrx, revealing an unexpected interaction between the two presynaptic hubs. These findings underscore the complex interplay of synapse organizers in specifying the molecular logic of a neural circuit.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Giro Denteado/metabolismo , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Moléculas de Adesão de Célula Nervosa/genética , Neurônios/metabolismo , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/genética , Sinapses/metabolismo , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Giro Denteado/patologia , Heparitina Sulfato/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores/metabolismo , Sinapses/patologia
5.
Exp Neurol ; 323: 113073, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639375

RESUMO

During mammalian embryonic development sensory and motor axons interact as an integral part of the pathfinding process. During regeneration, however, little is known of their interactions with one another. It is thus possible that sensory axons might influence motor axon regeneration in ways not currently appreciated. To explore this possibility we have developed an organotypic model of post-natal nerve regeneration in which sensory and motor axons are color-coded by modality. Motor axons that express yellow fluorescent protein (YFP) and sensory axons that express red fluorescent protein (RFP) are blended within a three-dimensional segment of peripheral nerve. This nerve is then transected, allowing axons to interact with one another as they grow out on a collagen/laminin gel that is initially devoid of directional cues. Within hours it is apparent that sensory axons extend more rapidly than motor axons and precede them during the early stages of regeneration, the opposite of their developmental order. Motor axons thus enter an environment already populated with sensory axons, and they adhere to these axons throughout most of their course. As a result, motor axon growth is reduced dramatically. Physical delay of sensory regeneration, allowing motor axons to grow ahead, restores normal motor growth; direct axonal interactions on the gel, rather than some other aspect of the model, are thus responsible for motor inhibition. Potential mechanisms for this inhibition are explored by electroporating siRNA to the neural cell adhesion molecule (NCAM) and the L1 adhesion molecule (L1CAM) into dorsal root ganglia (DRGs) to block expression of these molecules by regenerating sensory axons. Although neither maneuver improved motor regeneration, the results were consistent with early receptor-mediated signaling among axons rather than physical adhesion as the mechanism of motor inhibition in this model.


Assuntos
Axônios/fisiologia , Neurônios Motores/fisiologia , Regeneração Nervosa/fisiologia , Células Receptoras Sensoriais/fisiologia , Animais , Técnicas de Cocultura/métodos , Gânglios Espinais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Técnicas de Cultura de Órgãos/métodos , Nervos Periféricos/fisiologia , Medula Espinal/fisiologia
6.
Int J Mol Sci ; 20(24)2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31817246

RESUMO

Aging represents the accumulation of changes in an individual over time, encompassing physical, psychological, and social changes. Posttranslational modifications of proteins such as glycosylation, including sialylation or glycation, are proposed to be involved in this process, since they modulate a variety of molecular and cellular functions. In this study, we analyzed selected posttranslational modifications and the respective proteins on which they occur in young and old mouse brains. The expression of neural cell adhesion molecule (NCAM), receptor for advanced glycation endproducts (RAGE), as well as the carbohydrate-epitopes paucimannose and high-mannose, polysialic acid, and O-GlcNAc were examined. We demonstrated that mannose-containing glycans increased on glycoproteins in aged mouse brains and identified synapsin-1 as one major carrier of paucimannose in aged brains. In addition, we found an accumulation of so-called advanced glycation endproducts, which are generated by non-enzymatic reactions and interfere with protein function. Furthermore, we analyzed the expression of sialic acid and found also an increase during aging.


Assuntos
Envelhecimento , Encéfalo/metabolismo , Glicoproteínas/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Produtos Finais de Glicação Avançada/metabolismo , Glicoproteínas/análise , Glicosilação , Masculino , Manose/química , Manose/metabolismo , Espectrometria de Massas , Camundongos , Ácido N-Acetilneuramínico/análise , Moléculas de Adesão de Célula Nervosa/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo
7.
PLoS Biol ; 17(12): e3000522, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31805038

RESUMO

In epithelia, tricellular vertices are emerging as important sites for the regulation of epithelial integrity and function. Compared to bicellular contacts, however, much less is known. In particular, resident proteins at tricellular vertices were identified only at occluding junctions, with none known at adherens junctions (AJs). In a previous study, we discovered that in Drosophila embryos, the adhesion molecule Sidekick (Sdk), well-known in invertebrates and vertebrates for its role in the visual system, localises at tricellular vertices at the level of AJs. Here, we survey a wide range of Drosophila epithelia and establish that Sdk is a resident protein at tricellular AJs (tAJs), the first of its kind. Clonal analysis showed that two cells, rather than three cells, contributing Sdk are sufficient for tAJ localisation. Super-resolution imaging using structured illumination reveals that Sdk proteins form string-like structures at vertices. Postulating that Sdk may have a role in epithelia where AJs are actively remodelled, we analysed the phenotype of sdk null mutant embryos during Drosophila axis extension using quantitative methods. We find that apical cell shapes are abnormal in sdk mutants, suggesting a defect in tissue remodelling during convergence and extension. Moreover, adhesion at apical vertices is compromised in rearranging cells, with apical tears in the cortex forming and persisting throughout axis extension, especially at the centres of rosettes. Finally, we show that polarised cell intercalation is decreased in sdk mutants. Mathematical modelling of the cell behaviours supports the notion that the T1 transitions of polarised cell intercalation are delayed in sdk mutants, in particular in rosettes. We propose that this delay, in combination with a change in the mechanical properties of the converging and extending tissue, causes the abnormal apical cell shapes in sdk mutant embryos.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Proteínas do Olho/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Junções Íntimas/fisiologia , Junções Aderentes/metabolismo , Animais , Adesão Celular , Moléculas de Adesão Celular/metabolismo , Polaridade Celular/fisiologia , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/metabolismo , Epitélio/metabolismo , Proteínas do Olho/fisiologia , Proteínas de Membrana/metabolismo , Moléculas de Adesão de Célula Nervosa/fisiologia
8.
Nat Genet ; 51(12): 1679-1690, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31784728

RESUMO

NRXN1 undergoes extensive alternative splicing, and non-recurrent heterozygous deletions in NRXN1 are strongly associated with neuropsychiatric disorders. We establish that human induced pluripotent stem cell (hiPSC)-derived neurons well represent the diversity of NRXN1α alternative splicing observed in the human brain, cataloguing 123 high-confidence in-frame human NRXN1α isoforms. Patient-derived NRXN1+/- hiPSC-neurons show a greater than twofold reduction in half of the wild-type NRXN1α isoforms and express dozens of novel isoforms from the mutant allele. Reduced neuronal activity in patient-derived NRXN1+/- hiPSC-neurons is ameliorated by overexpression of individual control isoforms in a genotype-dependent manner, whereas individual mutant isoforms decrease neuronal activity levels in control hiPSC-neurons. In a genotype-dependent manner, the phenotypic impact of patient-specific NRXN1+/- mutations can occur through a reduction in wild-type NRXN1α isoform levels as well as the presence of mutant NRXN1α isoforms.


Assuntos
Processamento Alternativo , Proteínas de Ligação ao Cálcio/genética , Células-Tronco Pluripotentes Induzidas/fisiologia , Moléculas de Adesão de Célula Nervosa/genética , Esquizofrenia/genética , Animais , Transtorno do Espectro Autista/genética , Transtorno Bipolar/genética , Estudos de Casos e Controles , Transtorno Depressivo Maior/genética , Feminino , Expressão Gênica , Heterozigoto , Humanos , Masculino , Camundongos , Isoformas de Proteínas/genética , Deleção de Sequência
9.
EMBO J ; 38(22): e101603, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31566781

RESUMO

Neurexins are presynaptic, cell-adhesion molecules that specify the functional properties of synapses via interactions with trans-synaptic ligands. Neurexins are extensively alternatively spliced at six canonical sites that regulate multifarious ligand interactions, but the structural mechanisms underlying alternative splicing-dependent neurexin regulation are largely unknown. Here, we determined high-resolution structures of the complex of neurexophilin-1 and the second laminin/neurexin/sex-hormone-binding globulin domain (LNS2) of neurexin-1 and examined how alternative splicing at splice site #2 (SS2) regulates the complex. Our data reveal a unique, extensive, neurexophilin-neurexin binding interface that extends the jelly-roll ß-sandwich of LNS2 of neurexin-1 into neurexophilin-1. The SS2A insert of LNS2 augments this interface, increasing the binding affinity of LNS2 for neurexophilin-1. Taken together, our data reveal an unexpected architecture of neurexophilin-neurexin complexes that accounts for the modulation of binding by alternative splicing, which in turn regulates the competition of neurexophilin for neurexin binding with other ligands.


Assuntos
Processamento Alternativo , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Glicoproteínas/química , Glicoproteínas/metabolismo , Laminina/metabolismo , Moléculas de Adesão de Célula Nervosa/química , Moléculas de Adesão de Célula Nervosa/metabolismo , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Ligação ao Cálcio/genética , Cristalografia por Raios X , Glicoproteínas/genética , Ligantes , Camundongos , Modelos Moleculares , Moléculas de Adesão de Célula Nervosa/genética , Neuropeptídeos/genética , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Ratos , Homologia de Sequência
10.
PLoS Biol ; 17(10): e3000466, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658245

RESUMO

The pre- and postsynaptic membranes comprising the synaptic junction differ in protein composition. The membrane trafficking mechanisms by which neurons control surface polarization of synaptic receptors remain poorly understood. The sorting receptor Sortilin-related CNS expressed 1 (SorCS1) is a critical regulator of trafficking of neuronal receptors, including the presynaptic adhesion molecule neurexin (Nrxn), an essential synaptic organizer. Here, we show that SorCS1 maintains a balance between axonal and dendritic Nrxn surface levels in the same neuron. Newly synthesized Nrxn1α traffics to the dendritic surface, where it is endocytosed. Endosomal SorCS1 interacts with the Rab11 GTPase effector Rab11 family-interacting protein 5 (Rab11FIP5)/Rab11 interacting protein (Rip11) to facilitate the transition of internalized Nrxn1α from early to recycling endosomes and bias Nrxn1α surface polarization towards the axon. In the absence of SorCS1, Nrxn1α accumulates in early endosomes and mispolarizes to the dendritic surface, impairing presynaptic differentiation and function. Thus, SorCS1-mediated sorting in dendritic endosomes controls Nrxn axonal surface polarization required for proper synapse development and function.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Córtex Cerebral/metabolismo , Moléculas de Adesão de Célula Nervosa/genética , Neurônios/metabolismo , Receptores de Superfície Celular/genética , Membranas Sinápticas/metabolismo , Transmissão Sináptica/genética , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Polaridade Celular , Córtex Cerebral/citologia , Embrião de Mamíferos , Endocitose , Endossomos/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Neurônios/ultraestrutura , Cultura Primária de Células , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Transporte Proteico , Ratos , Ratos Wistar , Receptores de Superfície Celular/metabolismo , Membranas Sinápticas/ultraestrutura , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
11.
Curr Top Med Chem ; 19(25): 2271-2282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31648641

RESUMO

Polysialic acid (polySia) is a novel glycan that posttranslationally modifies neural cell adhesion molecules (NCAMs) in mammalian cells. Up-regulation of polySia-NCAM expression or NCAM polysialylation is associated with tumor cell migration and progression in many metastatic cancers and neurocognition. It has been known that two highly homologous mammalian polysialyltransferases (polySTs), ST8Sia II (STX) and ST8Sia IV (PST), can catalyze polysialylation of NCAM, and two polybasic domains, polybasic region (PBR) and polysialyltransferase domain (PSTD) in polySTs play key roles in affecting polyST activity or NCAM polysialylation. However, the molecular mechanisms of NCAM polysialylation and cell migration are still not entirely clear. In this minireview, the recent research results about the intermolecular interactions between the PBR and NCAM, the PSTD and cytidine monophosphate-sialic acid (CMP-Sia), the PSTD and polySia, and as well as the intramolecular interaction between the PBR and the PSTD within the polyST, are summarized. Based on these cooperative interactions, we have built a novel model of NCAM polysialylation and cell migration mechanisms, which may be helpful to design and develop new polysialyltransferase inhibitors.


Assuntos
Movimento Celular , Moléculas de Adesão de Célula Nervosa/metabolismo , Ácidos Siálicos/metabolismo , Animais , Humanos , Moléculas de Adesão de Célula Nervosa/química , Ácidos Siálicos/química
12.
Nat Commun ; 10(1): 4794, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641127

RESUMO

Central nervous system myelin is a multilayered membrane produced by oligodendrocytes to increase neural processing speed and efficiency, but the molecular mechanisms underlying axonal selection and myelin wrapping are unknown. Here, using combined morphological and molecular analyses in mice and zebrafish, we show that adhesion molecules of the paranodal and the internodal segment work synergistically using overlapping functions to regulate axonal interaction and myelin wrapping. In the absence of these adhesive systems, axonal recognition by myelin is impaired with myelin growing on top of previously myelinated fibers, around neuronal cell bodies and above nodes of Ranvier. In addition, myelin wrapping is disturbed with the leading edge moving away from the axon and in between previously formed layers. These data show how two adhesive systems function together to guide axonal ensheathment and myelin wrapping, and provide a mechanistic understanding of how the spatial organization of myelin is achieved.


Assuntos
Axônios/fisiologia , Sistema Nervoso Central/fisiologia , Bainha de Mielina/fisiologia , Moléculas de Adesão de Célula Nervosa/metabolismo , Animais , Animais Geneticamente Modificados , Adesão Celular/fisiologia , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Contactina 1/genética , Contactina 1/metabolismo , Feminino , Larva , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Bainha de Mielina/patologia , Glicoproteína Associada a Mielina/genética , Glicoproteína Associada a Mielina/metabolismo , Moléculas de Adesão de Célula Nervosa/genética , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
13.
BMC Res Notes ; 12(1): 595, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533814

RESUMO

OBJECTIVE: Resistance training (RT) can improve whole muscle strength without increasing muscle fiber size or contractility. Neural adaptations, which lead to greater neural activation of muscle, may mediate some of these improvements, particularly in older adults, where motor neuron denervation is common. The purpose of this study was to explore the relationship of neural adaptations, as reflected by neural cell adhesion molecule (NCAM) expression, to improvements in (1) whole muscle strength and (2) muscle fiber size following RT in older adults with knee osteoarthritis. We performed whole muscle strength measurements and immunohistochemical analysis of fiber size, type, and NCAM expression before and after a 14-week RT program. RESULTS: RT increased whole-muscle strength as measured by 1-repetition maximum (1-RM) leg press (P = 0.01), leg extension (P = 0.03), and knee extensor peak torque (P = 0.050), but did not alter NCAM expression. Greater NCAM expression in myosin heavy chain (MHC) II fibers was associated with greater whole muscle strength gains (knee extensor peak torque r = 0.93; P < 0.01) and greater MHC II fiber size (r = 0.79; P < 0.01). Our results suggest that training-induced NCAM expression, and neural adaptations more generally, may be important for RT-induced morphological and functional improvements in older adults. Trial registration NCT01190046.


Assuntos
Articulação do Joelho/fisiopatologia , Joelho/fisiopatologia , Músculo Esquelético/fisiopatologia , Moléculas de Adesão de Célula Nervosa/metabolismo , Osteoartrite do Joelho/fisiopatologia , Treinamento de Resistência/métodos , Adaptação Fisiológica , Idoso , Feminino , Humanos , Articulação do Joelho/metabolismo , Masculino , Pessoa de Meia-Idade , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/metabolismo , Osteoartrite do Joelho/metabolismo , Torque
14.
Transl Psychiatry ; 9(1): 230, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530798

RESUMO

Schizophrenia, Schizoaffective, and Bipolar disorders share behavioral and phenomenological traits, intermediate phenotypes, and some associated genetic loci with pleiotropic effects. Volumetric abnormalities in brain structures are among the intermediate phenotypes consistently reported associated with these disorders. In order to examine the genetic underpinnings of these structural brain modifications, we performed genome-wide association analyses (GWAS) on 60 quantitative structural brain MRI phenotypes in a sample of 777 subjects (483 cases and 294 controls pooled together). Genotyping was performed with the Illumina PsychChip microarray, followed by imputation to the 1000 genomes multiethnic reference panel. Enlargement of the Temporal Horns of Lateral Ventricles (THLV) is associated with an intronic SNP of the gene NRXN1 (rs12467877, P = 6.76E-10), which accounts for 4.5% of the variance in size. Enlarged THLV is associated with psychosis in this sample, and with reduction of the hippocampus and enlargement of the choroid plexus and caudate. Eight other suggestively significant associations (P < 5.5E-8) were identified with THLV and 5 other brain structures. Although rare deletions of NRXN1 have been previously associated with psychosis, this is the first report of a common SNP variant of NRXN1 associated with enlargement of the THLV in psychosis.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Ventrículos Laterais/diagnóstico por imagem , Moléculas de Adesão de Célula Nervosa/genética , Transtornos Psicóticos/genética , Adulto , Alelos , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Polimorfismo de Nucleotídeo Único , Transtornos Psicóticos/diagnóstico por imagem , Adulto Jovem
15.
EMBO J ; 38(17): e101289, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31368584

RESUMO

Synapse development requires spatiotemporally regulated recruitment of synaptic proteins. In this study, we describe a novel presynaptic mechanism of cis-regulated oligomerization of adhesion molecules that controls synaptogenesis. We identified synaptic adhesion-like molecule 1 (SALM1) as a constituent of the proposed presynaptic Munc18/CASK/Mint1/Lin7b organizer complex. SALM1 preferentially localized to presynaptic compartments of excitatory hippocampal neurons. SALM1 depletion in excitatory hippocampal primary neurons impaired Neurexin1ß- and Neuroligin1-mediated excitatory synaptogenesis and reduced synaptic vesicle clustering, synaptic transmission, and synaptic vesicle release. SALM1 promoted Neurexin1ß clustering in an F-actin- and PIP2-dependent manner. Two basic residues in SALM1's juxtamembrane polybasic domain are essential for this clustering. Together, these data show that SALM1 is a presynaptic organizer of synapse development by promoting F-actin/PIP2-dependent clustering of Neurexin.


Assuntos
Actinas/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Sinapses/metabolismo , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Células Cultivadas , Células HEK293 , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Glicoproteínas de Membrana/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Neurogênese
16.
Neurology ; 93(5): e433-e444, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31270218

RESUMO

OBJECTIVE: To identify molecular correlates of primary angiitis of the CNS (PACNS) through proteomic analysis of CSF from a biopsy-proven patient cohort. METHODS: Using mass spectrometry, we quantitatively compared the CSF proteome of patients with biopsy-proven PACNS (n = 8) to CSF from individuals with noninflammatory conditions (n = 11). Significantly enriched molecular pathways were identified with a gene ontology workflow, and high confidence hits within enriched pathways (fold change >1.5 and concordant Benjamini-Hochberg-adjusted p < 0.05 on DeSeq and t test) were identified as differentially regulated proteins. RESULTS: Compared to noninflammatory controls, 283 proteins were differentially expressed in the CSF of patients with PACNS, with significant enrichment of the complement cascade pathway (C4-binding protein, CD55, CD59, properdin, complement C5, complement C8, and complement C9) and neural cell adhesion molecules. A subset of clinically relevant findings were validated by Western blot and commercial ELISA. CONCLUSIONS: In this exploratory study, we found evidence of deregulation of the alternative complement cascade in CSF from biopsy-proven PACNS compared to noninflammatory controls. More specifically, several regulators of the C3 and C5 convertases and components of the terminal cascade were significantly altered. These preliminary findings shed light on a previously unappreciated similarity between PACNS and systemic vasculitides, especially anti-neutrophil cytoplasmic antibody-associated vasculitis. The therapeutic implications of this common biology and the diagnostic and therapeutic utility of individual proteomic findings warrant validation in larger cohorts.


Assuntos
Proteínas do Sistema Complemento/líquido cefalorraquidiano , Moléculas de Adesão de Célula Nervosa/líquido cefalorraquidiano , Proteômica , Vasculite do Sistema Nervoso Central/líquido cefalorraquidiano , Adolescente , Adulto , Biópsia , Encéfalo/patologia , Antígenos CD55/líquido cefalorraquidiano , Antígenos CD59/líquido cefalorraquidiano , Estudos de Casos e Controles , Estudos de Coortes , Proteína de Ligação ao Complemento C4b/líquido cefalorraquidiano , Complemento C5/líquido cefalorraquidiano , Complemento C8/líquido cefalorraquidiano , Complemento C9/líquido cefalorraquidiano , Via Alternativa do Complemento , Feminino , Ontologia Genética , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Properdina/líquido cefalorraquidiano , Vasculite do Sistema Nervoso Central/patologia
17.
J Cell Biol ; 218(8): 2677-2698, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31262725

RESUMO

Neurexins are well-characterized presynaptic cell adhesion molecules that engage multifarious postsynaptic ligands and organize diverse synapse properties. However, the precise synaptic localization of neurexins remains enigmatic. Using super-resolution microscopy, we demonstrate that neurexin-1 forms discrete nanoclusters at excitatory synapses, revealing a novel organizational feature of synaptic architecture. Synapses generally contain a single nanocluster that comprises more than four neurexin-1 molecules and that also includes neurexin-2 and/or neurexin-3 isoforms. Moreover, we find that neurexin-1 is physiologically cleaved by ADAM10 similar to its ligand neuroligin-1, with ∼4-6% of neurexin-1 and ∼2-3% of neuroligin-1 present in the adult brain as soluble ectodomain proteins. Blocking ADAM10-mediated neurexin-1 cleavage dramatically increased the synaptic neurexin-1 content, thereby elevating the percentage of Homer1(+) excitatory synapses containing neurexin-1 nanoclusters from 40-50% to ∼80%, and doubling the number of neurexin-1 molecules per nanocluster. Taken together, our results reveal an unexpected nanodomain organization of synapses in which neurexin-1 is assembled into discrete presynaptic nanoclusters that are dynamically regulated via ectodomain cleavage.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Nanopartículas/química , Moléculas de Adesão de Célula Nervosa/metabolismo , Sinapses/metabolismo , Proteína ADAM10/metabolismo , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Células Cultivadas , Epitopos/metabolismo , Células HEK293 , Humanos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Isoformas de Proteínas/metabolismo , Proteólise
18.
Rev Cardiovasc Med ; 20(2): 101-108, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31345003

RESUMO

Hypertension is a universal risk factor for a variety of cardiovascular diseases. Investigation of the mechanism for hypertension will benefit around 40% of the world's adult population. MicroRNA is crucial for the initiation and progression of cardiovascular diseases. In this study, angiotensin II-treated human umbilical vein endothelial cells were used as a model to imitate the pathological changes in endothelial cells under hypertensive conditions. We demonstrated that microRNA-9 (miR-9) suppressed angiotensin II-induced apoptosis and enhanced proliferation in human umbilical vein endothelial cells. Direct interaction between miR-9 and mitochondria associated membrance domain containing glycosylphosphatidylinositol anchor 2 (MDGA2) was determined. Moreover, miR-9 suppressed MDGA2 levels by binding to the 3' UTR site of the MDGA2 gene. This negative regulation of MDGA2 by miR-9 significantly increased proliferation and decreased apoptosis. Re-introduction of MDGA2 in the miR-9 overexpressed human umbilical vein endothelial cells and normalized proliferation, apoptosis, and the cell cycle. In summary, the present study demonstrated miR-9 inhibited expression of MDGA2 leading to the inhibition of apoptosis and promotion of proliferation in angiotensin II-treated human umbilical vein endothelial cells.


Assuntos
Angiotensina II/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteínas Ligadas por GPI/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , MicroRNAs/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Regiões 3' não Traduzidas , Sítios de Ligação , Células Cultivadas , Proteínas Ligadas por GPI/genética , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , MicroRNAs/genética , Moléculas de Adesão de Célula Nervosa/genética , Transdução de Sinais
19.
Dev Cell ; 50(3): 313-326.e5, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31353315

RESUMO

Tricellular adherens junctions are points of high tension that are central to the rearrangement of epithelial cells. However, the molecular composition of these junctions is unknown, making it difficult to assess their role in morphogenesis. Here, we show that Sidekick, an immunoglobulin family cell adhesion protein, is highly enriched at tricellular adherens junctions in Drosophila. This localization is modulated by tension, and Sidekick is itself necessary to maintain normal levels of cell bond tension. Loss of Sidekick causes defects in cell and junctional rearrangements in actively remodeling epithelial tissues like the retina and tracheal system. The adaptor proteins Polychaetoid and Canoe are enriched at tricellular adherens junctions in a Sidekick-dependent manner; Sidekick functionally interacts with both proteins and directly binds to Polychaetoid. We suggest that Polychaetoid and Canoe link Sidekick to the actin cytoskeleton to enable tricellular adherens junctions to maintain or transmit cell bond tension during epithelial cell rearrangements.


Assuntos
Junções Aderentes/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas do Olho/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Adesão Celular , Linhagem Celular , Proteínas de Drosophila/genética , Drosophila melanogaster , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Proteínas do Olho/genética , Moléculas de Adesão de Célula Nervosa/genética , Ligação Proteica , Proteínas de Junções Íntimas/genética , Proteínas de Junções Íntimas/metabolismo
20.
Dev Cell ; 50(3): 327-338.e5, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31353316

RESUMO

Remodeling of cell-cell junctions drives cell intercalation that causes tissue movement during morphogenesis through the shortening and growth of bicellular junctions. The growth of new junctions is essential for continuing and then completing cellular dynamics and tissue shape sculpting; however, the mechanism underlying junction growth remains obscure. We investigated Drosophila genitalia rotation where continuous cell intercalation occurs to show that myosin II accumulating at the vertices of a new junction is required for the junction growth. This myosin II accumulation requires the adhesive transmembrane protein Sidekick (Sdk), which localizes to the adherens junctions (AJs) of tricellular contacts (tAJs). Sdk also localizes to and blocks the accumulation of E-Cadherin at newly formed growing junctions, which maintains the growth rate. We propose that Sdk facilitates tAJ movement by mediating myosin II-driven contraction and altering the adhesive properties at the tAJs, leading to cell-cell junction extension during persistent junction remodeling.


Assuntos
Junções Aderentes/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas do Olho/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Animais , Caderinas/metabolismo , Linhagem Celular , Movimento Celular , Proteínas de Drosophila/genética , Drosophila melanogaster , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Proteínas do Olho/genética , Miosinas/metabolismo , Moléculas de Adesão de Célula Nervosa/genética
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