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1.
Nat Commun ; 12(1): 1451, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649316

RESUMO

Proprioceptive feedback mainly derives from groups Ia and II muscle spindle (MS) afferents and group Ib Golgi tendon organ (GTO) afferents, but the molecular correlates of these three afferent subtypes remain unknown. We performed single cell RNA sequencing of genetically identified adult proprioceptors and uncovered five molecularly distinct neuronal clusters. Validation of cluster-specific transcripts in dorsal root ganglia and skeletal muscle demonstrates that two of these clusters correspond to group Ia MS afferents and group Ib GTO afferent proprioceptors, respectively, and suggest that the remaining clusters could represent group II MS afferents. Lineage analysis between proprioceptor transcriptomes at different developmental stages provides evidence that proprioceptor subtype identities emerge late in development. Together, our data provide comprehensive molecular signatures for groups Ia and II MS afferents and group Ib GTO afferents, enabling genetic interrogation of the role of individual proprioceptor subtypes in regulating motor output.


Assuntos
Mecanorreceptores/metabolismo , Fusos Musculares/metabolismo , Neurônios Aferentes/metabolismo , Animais , Calbindina 2/metabolismo , Fenômenos Eletrofisiológicos , Canais Iônicos/metabolismo , Camundongos Transgênicos , Neurônios/metabolismo , Propriocepção , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Neurotransmissores/metabolismo , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Análise de Célula Única , Transcriptoma/genética
2.
PLoS Genet ; 16(6): e1008778, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32579604

RESUMO

Endurance exercise has broadly protective effects across organisms, increasing metabolic fitness and reducing incidence of several age-related diseases. Drosophila has emerged as a useful model for studying changes induced by chronic endurance exercise, as exercising flies experience improvements to various aspects of fitness at the cellular, organ and organismal level. The activity of octopaminergic neurons is sufficient to induce the conserved cellular and physiological changes seen following endurance training. All 4 octopamine receptors are required in at least one target tissue, but only one, Octß1R, is required for all of them. Here, we perform tissue- and adult-specific knockdown of alpha- and beta-adrenergic octopamine receptors in several target tissues. We find that reduced expression of Octß1R in adult muscles abolishes exercise-induced improvements in endurance, climbing speed, flight, cardiac performance and fat-body catabolism in male Drosophila. Importantly, Octß1R and OAMB expression in the heart is also required cell-nonautonomously for adaptations in other tissues, such as skeletal muscles in legs and adult fat body. These findings indicate that activation of distinct octopamine receptors in skeletal and cardiac muscle are required for Drosophila exercise adaptations, and suggest that cell non-autonomous factors downstream of octopaminergic activation play a key role.


Assuntos
Adaptação Fisiológica , Proteínas de Drosophila/metabolismo , Voo Animal , Coração/fisiologia , Músculo Esquelético/metabolismo , Miocárdio/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Receptores de Neurotransmissores/metabolismo , Animais , Drosophila , Proteínas de Drosophila/genética , Corpo Adiposo/metabolismo , Músculo Esquelético/fisiologia , Receptores Acoplados a Proteínas-G/genética , Receptores de Neurotransmissores/genética
3.
J Neurosci ; 40(27): 5177-5195, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32457074

RESUMO

Amacrine cells (ACs) are a diverse class of interneurons that modulate input from photoreceptors to retinal ganglion cells (RGCs), rendering each RGC type selectively sensitive to particular visual features, which are then relayed to the brain. While many AC types have been identified morphologically and physiologically, they have not been comprehensively classified or molecularly characterized. We used high-throughput single-cell RNA sequencing to profile >32,000 ACs from mice of both sexes and applied computational methods to identify 63 AC types. We identified molecular markers for each type and used them to characterize the morphology of multiple types. We show that they include nearly all previously known AC types as well as many that had not been described. Consistent with previous studies, most of the AC types expressed markers for the canonical inhibitory neurotransmitters GABA or glycine, but several expressed neither or both. In addition, many expressed one or more neuropeptides, and two expressed glutamatergic markers. We also explored transcriptomic relationships among AC types and identified transcription factors expressed by individual or multiple closely related types. Noteworthy among these were Meis2 and Tcf4, expressed by most GABAergic and most glycinergic types, respectively. Together, these results provide a foundation for developmental and functional studies of ACs, as well as means for genetically accessing them. Along with previous molecular, physiological, and morphologic analyses, they establish the existence of at least 130 neuronal types and nearly 140 cell types in the mouse retina.SIGNIFICANCE STATEMENT The mouse retina is a leading model for analyzing the development, structure, function, and pathology of neural circuits. A complete molecular atlas of retinal cell types provides an important foundation for these studies. We used high-throughput single-cell RNA sequencing to characterize the most heterogeneous class of retinal interneurons, amacrine cells, identifying 63 distinct types. The atlas includes types identified previously as well as many novel types. We provide evidence for the use of multiple neurotransmitters and neuropeptides, and identify transcription factors expressed by groups of closely related types. Combining these results with those obtained previously, we proposed that the mouse retina contains ∼130 neuronal types and is therefore comparable in complexity to other regions of the brain.


Assuntos
Células Amácrinas/classificação , Retina/citologia , Células Amácrinas/metabolismo , Células Amácrinas/ultraestrutura , Animais , Feminino , Glicina/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Proteínas de Homeodomínio/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Receptores de Neurotransmissores/classificação , Receptores de Neurotransmissores/metabolismo , Retina/ultraestrutura , Fator de Transcrição 4/metabolismo , Fatores de Transcrição/genética , Ácido gama-Aminobutírico/metabolismo
4.
Sci Rep ; 10(1): 8626, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451470

RESUMO

The study of postsynaptic excitation to inhibition (E/I ratio) imbalances in human brain diseases, is a highly relevant functional measurement poorly investigated due to postmortem degradation of synaptic receptors. We show that near-simultaneous recording of microtransplanted synaptic receptors after simulated morgue conditions allows the determination of the postsynaptic E/I ratio for at least 120 h after death, expanding the availability and use of human diseased tissue stored in brain banks.


Assuntos
Encéfalo/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciais Pós-Sinápticos Inibidores/fisiologia , Adulto , Animais , Encefalopatias/patologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Feminino , Humanos , Potenciais Pós-Sinápticos Inibidores/efeitos dos fármacos , Ácido Caínico/farmacologia , Masculino , Oócitos/citologia , Oócitos/metabolismo , Ratos , Ratos Wistar , Receptores de Neurotransmissores/metabolismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/fisiologia , Temperatura , Fatores de Tempo , Ácido gama-Aminobutírico/farmacologia
5.
Sci Adv ; 6(12): eaay5366, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32206712

RESUMO

Mammals exhibit instinctive reactions to danger critical to survival, including surges in blood stress hormones. Hypothalamic corticotropin-releasing hormone neurons (CRHNs) control stress hormones but how diverse stressors converge on CRHNs is poorly understood. We used sRNA profiling to define CRHN receptors for neurotransmitters and neuromodulators and then viral tracing to localize subsets of upstream neurons expressing cognate receptor ligands. Unexpectedly, one subset comprised POMC (proopiomelanocortin)-expressing neurons in the arcuate nucleus, which are linked to appetite suppression. The POMC neurons were activated by one psychological stressor, physical restraint, but not another, a predator odor. Chemogenetic activation of POMC neurons induced a stress hormone response, mimicking a stressor. Moreover, their silencing markedly reduced the stress hormone response to physical restraint, but not predator odor. These findings indicate that POMC neurons involved in appetite suppression also play a major role in the stress hormone response to a specific type of psychological stressor.


Assuntos
Apetite , Neurônios/fisiologia , Estresse Psicológico , Hormônio Liberador da Corticotropina/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Receptores de Neurotransmissores/metabolismo , Transdução de Sinais
6.
Biochem Biophys Res Commun ; 524(4): 890-894, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32057362

RESUMO

Osteoporosis is a disease of low bone mass that places individuals at enhanced risk for fracture, disability, and death. Osteoporosis rates are expected to rise significantly in the coming decades yet there are limited pharmacological treatment options, particularly for long-term management of this chronic condition. The drug development pipeline is relatively bereft of new strategies, causing an urgent and unmet need for developing new strategies and targets for treating osteoporosis. Here, we examine a lesser-studied bone remodeling pathway, Neuromedin U (NMU), which is expressed in the bone microenvironment along with its cognate receptors NMU receptor 1 (NMUR1) and 2 (NMUR2). We independently corroborate a prior report that global loss of NMU expression leads to high bone mass and test the hypothesis that NMU negatively regulates osteoblast differentiation. Consistent with this, in vitro studies reveal NMU represses osteoblastic differentiation of osteogenic precursors but, in contrast, promotes osteoblastic marker expression, proliferation and activity of osteoblast-like cells. Phospho-profiling arrays were used to detail differential signaling outcomes that may underlie the opposite responses of these cell types. Collectively, our findings indicate that NMU exerts cell-type-specific responses to regulate osteoblast differentiation and activity.


Assuntos
Neuropeptídeos/genética , Osteoblastos/metabolismo , Osteoporose/genética , Fosfoproteínas/genética , Receptores Acoplados a Proteínas-G/genética , Receptores de Neuropeptídeos/genética , Receptores de Neurotransmissores/genética , Animais , Densidade Óssea , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Diferenciação Celular , Linhagem Celular , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Knockout , Neuropeptídeos/metabolismo , Osteoblastos/patologia , Osteogênese/genética , Osteoporose/metabolismo , Osteoporose/patologia , Fosfoproteínas/classificação , Fosfoproteínas/metabolismo , Fosforilação , Receptores Acoplados a Proteínas-G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Receptores de Neurotransmissores/metabolismo , Transdução de Sinais
7.
FASEB J ; 34(1): 133-147, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914613

RESUMO

Neuromedin U (NMU), a highly conserved peptide in mammals, is involved in a wide variety of physiological processes. NMU, which is synthesized in ß-cells and co-localizes with insulin, directly acts on ß-cells via NMU receptor 1 (NMUR1) to suppress glucose-stimulated insulin secretion (GSIS). The mechanism underlying this insulinostatic effect has yet to be elucidated. We observed that NMU caused mitochondrial dysfunction by impairing mitochondrial biogenesis, respiration, and mitochondrial Ca2+ uptake in ß-cell-derived MIN6-K8 cells. NMU administration induced the endoplasmic reticulum (ER) stress, as reflected by the activation of ER stress signaling pathways involving ATF6, XBP-1s, and PERK-ATF4-CHOP. Nmu knockdown in MIN6-K8 cells increased the number of insulin granules and improved mitochondrial biogenesis and function. NMU was upregulated in both the islets of db/db mice and palmitate-treated MIN6-K8 cells. Our results highlight the crucial role of NMU in the maintenance of ß-cell function and glucose metabolism through regulation of mitochondria dysfunction and ER stress. In pathological stages that develop into diabetes, upregulation of NMU could suppress the insulin secretion by inducing mitochondrial dysfunction and ER stress, which may contribute to subsequent ß-cell dysfunction.


Assuntos
Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Insulina/metabolismo , Mitocôndrias/efeitos dos fármacos , Neuropeptídeos/farmacologia , Animais , Apoptose , Cálcio , Linhagem Celular Tumoral , Regulação da Expressão Gênica/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Insulinoma , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Interferência de RNA , Espécies Reativas de Oxigênio , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/metabolismo , Receptores de Neuropeptídeos/genética , Receptores de Neuropeptídeos/metabolismo , Receptores de Neurotransmissores/genética , Receptores de Neurotransmissores/metabolismo
8.
Neuron ; 105(4): 663-677.e8, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-31837915

RESUMO

A major function of GPCRs is to inhibit presynaptic neurotransmitter release, requiring ligand-activated receptors to couple locally to effectors at terminals. The current understanding of how this is achieved is through receptor immobilization on the terminal surface. Here, we show that opioid peptide receptors, GPCRs that mediate highly sensitive presynaptic inhibition, are instead dynamic in axons. Opioid receptors diffuse rapidly throughout the axon surface and internalize after ligand-induced activation specifically at presynaptic terminals. We delineate a parallel regulated endocytic cycle for GPCRs operating at the presynapse, separately from the synaptic vesicle cycle, which clears activated receptors from the surface of terminals and locally reinserts them to maintain the diffusible surface pool. We propose an alternate strategy for achieving local control of presynaptic effectors that, opposite to using receptor immobilization and enforced proximity, is based on lateral mobility of receptors and leverages the inherent allostery of GPCR-effector coupling.


Assuntos
Endocitose/fisiologia , Terminações Pré-Sinápticas/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Vesículas Sinápticas/metabolismo , Analgésicos Opioides/farmacologia , Animais , Células Cultivadas , Endocitose/efeitos dos fármacos , Ala(2)-MePhe(4)-Gly(5)-Encefalina/farmacologia , Terminações Pré-Sinápticas/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas-G/agonistas , Receptores de Neurotransmissores/agonistas , Receptores de Neurotransmissores/metabolismo , Vesículas Sinápticas/efeitos dos fármacos
9.
Oncogene ; 39(3): 503-515, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31527667

RESUMO

Neurotransmitters are conventionally viewed as nerve-secreted substances that mediate the stimulatory or inhibitory neuronal functions through binding to their respective receptors. In the past decades, many novel discoveries come to light elucidating the regulatory roles of neurotransmitters in the physiological and pathological functions of tissues and organs. Notably, emerging data suggest that cancer cells take advantage of the neurotransmitters-initiated signaling pathway to activate uncontrolled proliferation and dissemination. In addition, neurotransmitters can affect immune cells and endothelial cells in the tumor microenvironment to promote tumor progression. Therefore, a better understanding of the mechanisms underlying neurotransmitter function in tumorigenesis, angiogenesis, and inflammation is expected to enable the development of the next generation of antitumor therapies. Here, we summarize the recent important studies on the different neurotransmitters, their respective receptors, target cells, as well as pro/antitumor activity of specific neurotransmitter/receptor axis in cancers and provide perspectives and insights regarding the rationales and strategies of targeting neurotransmitter system to cancer treatment.


Assuntos
Inflamação/patologia , Neoplasias/patologia , Neovascularização Patológica/patologia , Neurotransmissores/metabolismo , Receptores de Neurotransmissores/metabolismo , Animais , Antineoplásicos/uso terapêutico , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Modelos Animais de Doenças , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Camundongos , Neoplasias/irrigação sanguínea , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/imunologia , Neurotransmissores/antagonistas & inibidores , Receptores de Neurotransmissores/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia
10.
Nutrients ; 11(11)2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31717954

RESUMO

We have previously shown that 6 weeks of intermittent high-fat diet (Int-HFD) pre-exposure significantly reduced alcohol drinking in rats, providing preliminary evidence of the effectiveness of a dietary intervention in reducing alcohol intake. However, the functional framework and underlying neurobiological mechanisms of such dietary intervention are unknown. Here, we examined the impact of Int-HFD pre-exposure duration on alcohol drinking, plasma feeding peptides, and central neurotransmitter receptors gene expression. Male Long Evans rats (n = 6-7/group) received no pre-exposure, 1 or 2 weeks pre-exposure to Int-HFD and alcohol drinking (two-bottle choice) was evaluated. We observed HFD pre-exposure-dependent decrease in alcohol drinking, with a significant decrease observed following 2 weeks of Int-HFD pre-exposure. No significant between-group differences in plasma feeding peptides (i.e., ghrelin, leptin, insulin) were detected. A PCR array revealed that the expression of several neurotransmitter receptors was significantly (p < 0.05 and ≥2-fold) altered in the striatum and ventral tegmental area compared to controls. These data suggest that pre-exposure to a palatable diet is critical to reduce alcohol drinking in rats, possibly through genetic alterations in the brain reward circuitry. Importantly, the present study is a step forward in identifying the critical framework needed to evaluate the therapeutic potential of nutritional contingency in the management of alcoholism.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Dieta Hiperlipídica , Receptores de Neurotransmissores/metabolismo , Animais , Peso Corporal , Gorduras na Dieta/metabolismo , Comportamento Alimentar , Masculino , Hormônios Peptídicos/metabolismo , Ratos , Ratos Long-Evans , Transcriptoma
11.
Cell ; 179(2): 498-513.e22, 2019 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-31585084

RESUMO

Neuromodulators bind to pre- and postsynaptic G protein-coupled receptors (GPCRs), are able to quickly change intracellular cyclic AMP (cAMP) and Ca2+ levels, and are thought to play important roles in neuropsychiatric and neurodegenerative diseases. Here, we discovered in human neurons an unanticipated presynaptic mechanism that acutely changes synaptic ultrastructure and regulates synaptic communication. Activation of neuromodulator receptors bidirectionally controlled synaptic vesicle numbers within nerve terminals. This control correlated with changes in the levels of cAMP-dependent protein kinase A-mediated phosphorylation of synapsin-1. Using a conditional deletion approach, we reveal that the neuromodulator-induced control of synaptic vesicle numbers was largely dependent on synapsin-1. We propose a mechanism whereby non-phosphorylated synapsin-1 "latches" synaptic vesicles to presynaptic clusters at the active zone. cAMP-dependent phosphorylation of synapsin-1 then removes the vesicles. cAMP-independent dephosphorylation of synapsin-1 in turn recruits vesicles. Synapsin-1 thereby bidirectionally regulates synaptic vesicle numbers and modifies presynaptic neurotransmitter release as an effector of neuromodulator signaling in human neurons.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Terminações Pré-Sinápticas/metabolismo , Sinapsinas/metabolismo , Transmissão Sináptica , Vesículas Sinápticas/metabolismo , Animais , Células Cultivadas , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Neurotransmissores/metabolismo , Receptores de Neurotransmissores/metabolismo , Transdução de Sinais
12.
Stem Cell Rev Rep ; 15(6): 851-863, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31529274

RESUMO

Adipose stromal cells are promising tools for clinical applications in regeneration therapies, due to their ease of isolation from tissue and its high yield; however, their ability to transdifferentiate into neural phenotypes is still a matter of controversy. Here, we show that combined chemical and neurotrophin stimulation resulted in neuron-like morphology and regulated expression and activity of several genes involved in neurogenesis and neurotransmission as well as ion currents mediated by NMDA and GABA receptors. Among them, expression patterns of genes coding for kinin-B1 and B2, α7 nicotinic, M1, M3 and M4 muscarinic acetylcholine, glutamatergic (AMPA2 and mGlu2), purinergic P2Y1 and P2Y4 and GABAergic (GABA-A, ß3-subunit) receptors and neuronal nitric oxide synthase were up-regulated compared to levels of undifferentiated cells. Simultaneously, expression levels of P2X1, P2X4, P2X7 and P2Y6 purinergic and M5 muscarinic acetylcholine receptors were down-regulated. Agonist-induced activity levels of the studied receptor classes also augmented during neuronal transdifferentiation. Transdifferentiated cells expressed high levels of neuronal ß3-tubulin, NF-H, NeuN and MAP-2 proteins as well as increased ASCL1, MYT1 and POU3F2 gene expression known to drive neuronal fate determination. The presented work contributes to a better understanding of transdifferentiation induced by neurotrophins for a prospective broad spectrum of medical applications.


Assuntos
Adipócitos/citologia , Transdiferenciação Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores de Crescimento Neural/farmacologia , Neurônios/citologia , Receptores de Neurotransmissores/metabolismo , Células Estromais/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Cálcio/metabolismo , Células Cultivadas , Humanos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Receptores de Neurotransmissores/genética , Transdução de Sinais , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo
13.
Brain Struct Funct ; 224(8): 2733-2756, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31392403

RESUMO

The macaque monkey superior parietal lobule (SPL) is part of a neuronal network involved in the integration of information from visual and somatosensory cortical areas for execution of reaching and grasping movements. We applied quantitative in vitro receptor autoradiography to analyse the distribution patterns of 15 different receptors for glutamate, GABA, acetylcholine, serotonin, dopamine, and adenosine in the SPL of three adult male Macaca fascicularis monkeys. For each area, mean (averaged over all cortical layers) receptor densities were visualized as a receptor fingerprint of that area. Multivariate analyses were conducted to detect clusters of areas according to the degree of (dis)similarity of their receptor organization. Differences in regional and laminar receptor distributions confirm the location and extent of areas V6, V6Av, V6Ad, PEc, PEci, and PGm as found in cytoarchitectonic and functional studies, but also enable the definition of three subdivisions within area PE. Receptor densities are higher in supra- than in infragranular layers, with the exception of kainate, M2, and adenosine receptors. Glutamate and GABAergic receptors are the most expressed in all areas analysed. Hierarchical cluster analyses demonstrate that SPL areas are organized in two groups, an organization that corresponds to the visual or sensory-motor characteristics of those areas. Finally, based on present results and in the framework of our current understanding of the structural and functional organization of the primate SPL, we propose a novel pattern of homologies between human and macaque SPL areas.


Assuntos
Neurônios/citologia , Neurônios/metabolismo , Lobo Parietal/citologia , Lobo Parietal/metabolismo , Receptores de Neurotransmissores/metabolismo , Animais , Autorradiografia , Macaca fascicularis , Masculino , Receptores Colinérgicos/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores de GABA/metabolismo , Receptores de Glutamato/metabolismo , Receptores Purinérgicos P1/metabolismo , Receptores de Serotonina/metabolismo
14.
Biochem Biophys Res Commun ; 517(3): 433-438, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31376933

RESUMO

Neuromedin U (NMU) plays important roles in energy homeostasis in rodents and birds. Previously, our group has isolated four cDNAs encoding precursor proteins of NMU from the goldfish brain and gut, and it was assumed that these transcripts are produced by alternative splicing. We have also demonstrated that intracerebroventricular (ICV) injection of putative goldfish NMU inhibits food intake. However, as native goldfish NMU has not yet been identified, we attempted to purify it from goldfish brain and gut extracts. To assess NMU activity in fractions at each purification step, we measured changes in the intracellular concentrations of Ca2+ using HEK293 cells expressing goldfish NMU-R1 or -R2. We isolated a 25-amino-acid peptide (NMU-25) from the brain and gut and found that its primary structure is similar to that of mammalian NMU. Another 21-amino-acid peptide (NMU-21) was purified from the brain, but not from the gut. Furthermore, a 9-amino-acid peptide (NMU-9) identical to the C-terminus of NMU-21 and -25 was also isolated from the brain and gut. Treatment with synthetic NMU-9, -21 and -25 dose-dependently increased the intracellular Ca2+ concentration in mammalian cells expressing goldfish NMU-R1 and -R2. We also examined the effect of ICV-administered synthetic goldfish NMUs on goldfish food intake. NMU-25 inhibited food intake to the same degree as NMU-21. However, the inhibitory effect of NMU-9 was slightly weaker than those of NMU-21 and -25. These results indicate that several molecular forms of NMU exist in the goldfish brain and gut, and that all of them play physiological roles via NMU-R1 and NMU-R2.


Assuntos
Encéfalo/metabolismo , Proteínas de Peixes/genética , Trato Gastrointestinal/metabolismo , Carpa Dourada/genética , Neuropeptídeos/genética , Receptores de Neurotransmissores/genética , Sequência de Aminoácidos , Animais , Transporte Biológico , Cálcio/metabolismo , Galinhas , Ingestão de Alimentos/fisiologia , Feminino , Proteínas de Peixes/isolamento & purificação , Proteínas de Peixes/metabolismo , Proteínas de Peixes/farmacologia , Expressão Gênica , Carpa Dourada/metabolismo , Células HEK293 , Humanos , Masculino , Neuropeptídeos/isolamento & purificação , Neuropeptídeos/metabolismo , Neuropeptídeos/farmacologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/isolamento & purificação , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , Ratos , Receptores de Neurotransmissores/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transgenes
15.
Cells ; 8(9)2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466388

RESUMO

Although acetylcholine is the major neurotransmitter operating at the skeletal neuromuscular junction of many invertebrates and of vertebrates, glutamate participates in modulating cholinergic transmission and plastic changes in the last. Presynaptic terminals of neuromuscular junctions contain and release glutamate that contribute to the regulation of synaptic neurotransmission through its interaction with pre- and post-synaptic receptors activating downstream signaling pathways that tune synaptic efficacy and plasticity. During vertebrate development, the chemical nature of the neurotransmitter at the vertebrate neuromuscular junction can be experimentally shifted from acetylcholine to other mediators (including glutamate) through the modulation of calcium dynamics in motoneurons and, when the neurotransmitter changes, the muscle fiber expresses and assembles new receptors to match the nature of the new mediator. Finally, in adult rodents, by diverting descending spinal glutamatergic axons to a denervated muscle, a functional reinnervation can be achieved with the formation of new neuromuscular junctions that use glutamate as neurotransmitter and express ionotropic glutamate receptors and other markers of central glutamatergic synapses. Here, we summarize the past and recent experimental evidences in support of a role of glutamate as a mediator at the synapse between the motor nerve ending and the skeletal muscle fiber, focusing on the molecules and signaling pathways that are present and activated by glutamate at the vertebrate neuromuscular junction.


Assuntos
Acetilcolina/metabolismo , Ácido Glutâmico/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Junção Neuromuscular/fisiologia , Transmissão Sináptica/fisiologia , Animais , Cálcio/metabolismo , Humanos , Camundongos , Neurônios Motores/citologia , Neurônios Motores/metabolismo , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Terminações Pré-Sinápticas/metabolismo , Ratos , Receptores de Neurotransmissores/metabolismo
16.
Eur J Neurosci ; 50(10): 3627-3662, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31293027

RESUMO

The identification of neuronal markers, that is, molecules selectively present in subsets of neurons, contributes to our understanding of brain areas and the networks within them. Specifically, recognizing the distribution of different neuronal markers facilitates the identification of borders between functionally distinct brain areas. Detailed knowledge about the localization and physiological significance of neuronal markers may also provide clues to generate new hypotheses concerning aspects of normal and abnormal brain functioning. Here, we provide a comprehensive review on the distribution within the entorhinal cortex of neuronal markers and the morphology of the neurons they reveal. Emphasis is on the comparative distribution of several markers, with a focus on, but not restricted to rodent, monkey and human data, allowing to infer connectional features, across species, associated with these markers, based on what is revealed by mainly rodent data. The overall conclusion from this review is that there is an emerging pattern in the distribution of neuronal markers in the entorhinal cortex when aligning data along a comparable coordinate system in various species.


Assuntos
Córtex Entorrinal/citologia , Técnicas de Rastreamento Neuroanatômico/métodos , Neurônios/metabolismo , Animais , Córtex Entorrinal/metabolismo , Córtex Entorrinal/fisiologia , Humanos , Vias Neurais/citologia , Vias Neurais/metabolismo , Vias Neurais/fisiologia , Técnicas de Rastreamento Neuroanatômico/normas , Neurônios/citologia , Neurônios/fisiologia , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Receptores de Neurotransmissores/genética , Receptores de Neurotransmissores/metabolismo , Roedores , Especificidade da Espécie
18.
Cell Mol Neurobiol ; 39(8): 1071-1080, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31222426

RESUMO

Calcium signaling has essential roles in the development of the nervous system, from neural induction to the proliferation, migration, and differentiation of both neuronal and glia cells. The temporal and spatial dynamics of Ca2+ signals control the highly diverse yet specific transcriptional programs that establish the complex structures of the nervous system. Ca2+-signaling pathways are shaped by interactions among metabotropic signaling cascades, ion channels, intracellular Ca2+ stores, and a multitude of downstream effector proteins that activate specific genetic programs. Progress in the last decade has led to significant advances in our understanding of the functional architecture of Ca2+ signaling networks involved in oligodendrocyte development. In this review, we summarize the molecular and functional organizations of Ca2+-signaling networks during the differentiation of oligodendrocyte, especially its impact on myelin gene expression, proliferation, migration, and myelination. Importantly, the existence of multiple routes of Ca2+ influx opens the possibility that the activity of calcium channels can be manipulated pharmacologically to encourage oligodendrocyte maturation and remyelination after demyelinating episodes in the brain.


Assuntos
Sinalização do Cálcio , Oligodendroglia/metabolismo , Animais , Axônios/metabolismo , Canais de Cálcio/metabolismo , Humanos , Bainha de Mielina/metabolismo , Receptores de Neurotransmissores/metabolismo
19.
Cell Microbiol ; 21(9): e13044, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31099148

RESUMO

Staphylococcus aureus is a facultative intracellular pathogen that invades a wide range of professional and nonprofessional phagocytes by triggering internalisation by interaction of surface-bound adhesins with corresponding host cell receptors. Here, we identified a new concept of host cell internalisation in animal-pathogenic staphylococcal species. This new mechanism exemplified by Staphylococcus pseudintermedius ED99 is not based on surface-bound adhesins but is due to excreted small neurochemical compounds, such as trace amines (TAs), dopamine (DOP), and serotonin (SER), that render host cells competent for bacterial internalisation. The neurochemicals are produced by only one enzyme, the staphylococcal aromatic amino acid decarboxylase (SadA). Here, we unravelled the mechanism of how neurochemicals trigger internalisation into the human colon cell line HT-29. We found that TAs and DOP are agonists of the α2-adrenergic receptor, which, when activated, induces a cascade of reactions involving a decrease in the cytoplasmic cAMP level and an increase in F-actin formation. The signalling cascade of SER follows a different pathway. SER interacts with 5HT receptors that trigger F-actin formation without decreasing the cytoplasmic cAMP level. The neurochemical-induced internalisation in host cells is independent of the fibronectin-binding protein pathway and has an additive effect. In a sadA deletion mutant, ED99ΔsadA, internalisation was decreased approximately threefold compared with that of the parent strain, and treating S. aureus USA300 with TAs increased internalisation by approximately threefold.


Assuntos
Descarboxilases de Aminoácido-L-Aromático/metabolismo , Células Epiteliais/metabolismo , Neurotransmissores/farmacologia , Staphylococcus/enzimologia , Actinas/metabolismo , Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Adulto , Idoso , Animais , Descarboxilases de Aminoácido-L-Aromático/genética , Linhagem Celular Tumoral , AMP Cíclico/metabolismo , Citoplasma/metabolismo , Dopamina/metabolismo , Dopamina/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/microbiologia , Fibronectinas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Neurotransmissores/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Receptores de Neurotransmissores/agonistas , Receptores de Neurotransmissores/metabolismo , Serotonina/metabolismo , Serotonina/farmacologia , Transdução de Sinais , Staphylococcus/efeitos dos fármacos , Staphylococcus/metabolismo , Staphylococcus/patogenicidade , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade
20.
Gen Comp Endocrinol ; 280: 73-81, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30981702

RESUMO

Evidence has shown that neuromedin S (NMS) and its receptor (NMU2R) are expressed in the hypothalamus, pituitary, and testis of pigs. To determine the potential mechanisms of NMS, we systematically investigated the direct effects of NMS on the hypothalamic-pituitary-testicular (HPT) axis of male pigs in vitro. We initially confirmed that NMU2R distributed in isolated hypothalamic cells, anterior pituitary cells and Leydig cells using immunocytochemistry. Subsequently we investigated the direct effects of NMS on hormone secretion from cells (anterior pituitary cells and Leydig cells) treated with different doses of NMS. The results showed that NMS increase the release of LH and FSH from anterior pituitary cells and testosterone from Leydig cells. NMS up-regulated the expression of NMU2R and GnRH mRNAs in hypothalamic cells, NMU2R, LH and FSH mRNAs in anterior pituitary cells, and NMU2R, STAR, P450 and 3ß-HSD mRNAs and the expression of PCNA and Cyclin B1 protein in Leydig cells; moreover, it down-regulated the expression of GnIH mRNA in hypothalamic cells. Using immunofluorescence staining and confocal microscopy, we also demonstrated the colocalization of NMU2R and AR or GnIH in Leydig cells. These data in vitro indicated that NMS may regulate the release and/or synthesis of LH, FSH and testosterone at different levels of the reproductive axis through NMU2R, which provided novel evidence of the potential roles of NMS in regulation of pig reproduction.


Assuntos
Hipotálamo/metabolismo , Neuropeptídeos/farmacologia , Hipófise/metabolismo , Testículo/metabolismo , Animais , Ciclina B1/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/efeitos dos fármacos , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Masculino , Hipófise/efeitos dos fármacos , Antígeno Nuclear de Célula em Proliferação/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Neurotransmissores/metabolismo , Suínos , Testículo/efeitos dos fármacos , Testosterona/metabolismo
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