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1.
Nat Commun ; 11(1): 4033, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820167

RESUMO

Peptide hormones and neuropeptides encompass a large class of bioactive peptides that regulate physiological processes like anxiety, blood glucose, appetite, inflammation and blood pressure. Here, we execute a focused discovery strategy to provide an extensive map of O-glycans on peptide hormones. We find that almost one third of the 279 classified peptide hormones carry O-glycans. Many of the identified O-glycosites are conserved and are predicted to serve roles in proprotein processing, receptor interaction, biodistribution and biostability. We demonstrate that O-glycans positioned within the receptor binding motifs of members of the neuropeptide Y and glucagon families modulate receptor activation properties and substantially extend peptide half-lives. Our study highlights the importance of O-glycosylation in the biology of peptide hormones, and our map of O-glycosites in this large class of biomolecules serves as a discovery platform for an important class of molecules with potential opportunities for drug designs.


Assuntos
Hormônios Peptídicos/química , Hormônios Peptídicos/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Idoso , Animais , Linhagem Celular , Desenho de Fármacos , Feminino , Glicosilação , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Neuropeptídeos/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Estabilidade Proteica , Ratos , Suínos
2.
PLoS Biol ; 18(8): e3000548, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745077

RESUMO

Sleep is vital for survival. Yet under environmentally challenging conditions, such as starvation, animals suppress their need for sleep. Interestingly, starvation-induced sleep loss does not evoke a subsequent sleep rebound. Little is known about how starvation-induced sleep deprivation differs from other types of sleep loss, or why some sleep functions become dispensable during starvation. Here, we demonstrate that down-regulation of the secreted cytokine unpaired 2 (upd2) in Drosophila flies may mimic a starved-like state. We used a genetic knockdown strategy to investigate the consequences of upd2 on visual attention and sleep in otherwise well-fed flies, thereby sidestepping the negative side effects of undernourishment. We find that knockdown of upd2 in the fat body (FB) is sufficient to suppress sleep and promote feeding-related behaviors while also improving selective visual attention. Furthermore, we show that this peripheral signal is integrated in the fly brain via insulin-expressing cells. Together, these findings identify a role for peripheral tissue-to-brain interactions in the simultaneous regulation of sleep quality and attention, to potentially promote adaptive behaviors necessary for survival in hungry animals.


Assuntos
Atenção/fisiologia , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Comportamento Alimentar/fisiologia , Inanição/genética , Percepção Visual/fisiologia , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Corpo Adiposo/metabolismo , Feminino , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Insulina/genética , Insulina/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Transdução de Sinais , Sono/fisiologia , Privação do Sono/genética , Privação do Sono/metabolismo , Inanição/metabolismo
3.
Nat Commun ; 11(1): 3962, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32770059

RESUMO

Social context can dampen or amplify the perception of touch, and touch in turn conveys nuanced social information. However, the neural mechanism behind social regulation of mechanosensation is largely elusive. Here we report that fruit flies exhibit a strong defensive response to mechanical stimuli to their wings. In contrast, virgin female flies being courted by a male show a compromised defensive response to the stimuli, but following mating the response is enhanced. This state-dependent switch is mediated by a functional reconfiguration of a neural circuit labelled with the Tmc-L gene in the ventral nerve cord. The circuit receives excitatory inputs from peripheral mechanoreceptors and coordinates the defensive response. While male cues suppress it via a doublesex (dsx) neuronal pathway, mating sensitizes it by stimulating a group of uterine neurons and consequently activating a leucokinin-dependent pathway. Such a modulation is crucial for the balance between defense against body contacts and sexual receptivity.


Assuntos
Drosophila melanogaster/fisiologia , Vias Neurais/fisiologia , Comportamento Sexual Animal/fisiologia , Alelos , Animais , Corte , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Feminino , Neurônios GABAérgicos/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Mecanorreceptores/metabolismo , Mutação/genética , Neuropeptídeos/metabolismo , Útero/inervação , Asas de Animais/inervação
4.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 40(7): 1001-1007, 2020 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-32701233

RESUMO

OBJECTIVE: To explore the effects of taurolithocholic acid (tLCA) and chenodeoxycholic acid (CDCA) on the expression of aorexigenic neuropeptide in mouse hypothalamus GT1-7 cells. METHODS: Mouse hypothalamic GT1-7 cells were treated with culture medium containing 10% FBS (control group, n=3) or with 10 nmol/L, 100 nmol/L, 1 µmol/L and 10 µmol/L tLCA (tLCA group, n=3) or CDCA (CDCA group, n=3) for 12, 24 or 48 h. Real-time PCR was performed to determine the expression levels of proopiomelanocortin (POMC) mRNA in the cells, and the production levels of α-melanocyte-stimulating hormone (α-MSH) were assessed using an ELISA kit. Signal transduction and activator of transcription 3 phosphorylation (p-STAT3), threonine kinase phosphorylation (p-AKT), suppressor of cytokine signaling 3 (SOCS3), G protein-coupled bile acid receptor-1 (TGR5) and farnesoid X receptor (FXR) protein were detected by Western blotting. RESULTS: Western blotting results showed that mouse hypothalamic GT1-7 cells expressed two bile acid receptors, TGR5 and FXR, whose expressions were regulated by bile acids. Real-time PCR showed that the expression of POMC mRNA was significantly increased in the cells after treatment with 10 µmol/L tLCA or CDCA for 24 h. POMC-derived anorexigenic peptide α-MSH increased significantly in GT1-7 cells after treatment with 10 µmol/L tLCA or CDCA for 24 h. Treatment of the cells with tLCA or CDCA significantly increased the expressions of intracellular signaling proteins including p-STAT3, p-AKT and SOCS3. CONCLUSIONS: Mouse hypothalamic GT1-7 cells express bile acid receptors TGR5 and FXR. Bile acids tLCA or CDCA can promote the expression of POMC mRNA and increase the production of the anorexigenic peptide α-MSH. The intracellular signaling proteins p-AKT, p-STAT3 and SOCS3 are likely involved in bile acid-induced anorexigenic peptide production.


Assuntos
Ácido Quenodesoxicólico , Regulação da Expressão Gênica , Pró-Opiomelanocortina , Transdução de Sinais , Ácido Taurolitocólico , alfa-MSH , Animais , Linhagem Celular , Ácido Quenodesoxicólico/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hipotálamo/citologia , Camundongos , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Pró-Opiomelanocortina/genética , RNA Mensageiro/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Ácido Taurolitocólico/farmacologia , alfa-MSH/genética
5.
Life Sci ; 258: 118029, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619495

RESUMO

OBJECTIVE: Hepatitis B virus (HBV) infection causes liver fibrosis, cirrhosis and hepatocellular carcinoma (HCC) development, but the underlying mechanism remains poorly understood. This study aimed to investigate the roles and molecular mechanisms of Dystrobrevin-α (DTNA) in HBV-induced liver cirrhosis and HCC pathogenesis. METHODS: DTNA expression was bioinformatically analyzed using the GEO database. DTNA expression was silenced by transfection with shRNAs. Cell proliferation and apoptosis were evaluated by MTT and flow cytometry respectively. The expression of genes in mRNA or protein levels was assessed by quantitative RT-PCR and western blotting. The interaction between proteins was predicted with the String and GCBI online softwares, and then confirmed by co-immunoprecipitation. Animal models were established by injecting nude mice with AVV8-HBV1.3 vector. RESULTS: Bioinformatics analysis showed a significantly increase in DTNA expression in HBV-positive liver cirrhosis and HCC patients. HBV infection caused a significantly increase in DTNA expression in HCC cell lines HepAD38 and HepG2.2.15. DTNA knockdown suppressed proliferation and promoted apoptosis of HBV-infected HepAD38 and HepG2.2.15 cells. HBV induced elevated expression of fibrosis-related genes Collagen II and TGFß1 in LO-2 cells, which were suppressed by DTNA knockdown. DTNA directly binded with STAT3 protein to promote STAT3 phosphorylation and TGFß1 expression and repress P53 expression in HBV-infected HepAD38 and LO-2 cells. The DTNA/STAT3 axis was activated during HBV-induced fibrosis, cirrhosis and HCC development in mouse model. CONCLUSION: DTNA binds with and further activates STAT3 to induce TGFß1 expression and repress P53 expression, thus promoting HBV-induced liver fibrosis, cirrhosis and hepatocellular carcinoma progression.


Assuntos
Carcinoma Hepatocelular/virologia , Progressão da Doença , Proteínas Associadas à Distrofina/metabolismo , Vírus da Hepatite B/fisiologia , Neoplasias Hepáticas/virologia , Neuropeptídeos/metabolismo , Fator de Transcrição STAT3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose , Carcinoma Hepatocelular/patologia , Proliferação de Células , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Células Hep G2 , Hepatite B , Humanos , Cirrose Hepática/complicações , Neoplasias Hepáticas/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Ligação Proteica , Transdução de Sinais
6.
Life Sci ; 256: 117976, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32561397

RESUMO

AIMS: We have previously reported that Centchroman (CC), an oral contraceptive drug, inhibits breast cancer progression and metastasis. In this study, we investigated whether CC inhibits local invasion of tumor cells and/or their metastatic colonization with detailed underlying mechanisms. MAIN METHODS: The effect of CC on the experimental metastasis and spontaneous metastasis was demonstrated by using tail-vein and orthotopic 4T1-syngeneic mouse tumor models, respectively. The anti-angiogenic potential of CC was evaluated using well established in vitro and in vivo models. The role of RAC1/PAK1/ß-catenin signaling axis in the metastasis was investigated and validated using siRNA-mediated knockdown of PAK1 as well as by pharmacological PAK1-inhibitor. KEY FINDINGS: The oral administration of CC significantly suppressed the formation of metastatic lung nodules in the 4T1-syngeneic orthotopic as well as experimental metastatic models. More importantly, CC treatment suppressed the tube formation and migration capacities of human umbilical vein endothelial cells (HUVEC) and inhibited pre-existing vasculature as well as the formation of neovasculature. The suppression of migration and invasion capacities of metastatic breast cancer cells upon CC treatment was associated with the inhibition of small GTPases (Rac1 and Cdc42) concomitant with the downregulation of PAK1 and downstream ß-catenin signaling. In addition, CC upregulated the expression of miR-145, which is known to target PAK1. SIGNIFICANCE: This study warrants the repurposing of CC as a potential therapeutic agent against metastatic breast cancer.


Assuntos
Neoplasias da Mama/metabolismo , Centocromano/farmacologia , Antagonistas de Estrogênios/farmacologia , Neuropeptídeos/antagonistas & inibidores , beta Catenina/antagonistas & inibidores , Quinases Ativadas por p21/antagonistas & inibidores , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Animais , Neoplasias da Mama/tratamento farmacológico , Centocromano/uso terapêutico , Antagonistas de Estrogênios/uso terapêutico , Feminino , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Neuropeptídeos/metabolismo , Distribuição Aleatória , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , beta Catenina/metabolismo , Quinases Ativadas por p21/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo
7.
Nature ; 582(7811): 246-252, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32499648

RESUMO

A wealth of specialized neuroendocrine command systems intercalated within the hypothalamus control the most fundamental physiological needs in vertebrates1,2. Nevertheless, we lack a developmental blueprint that integrates the molecular determinants of neuronal and glial diversity along temporal and spatial scales of hypothalamus development3. Here we combine single-cell RNA sequencing of 51,199 mouse cells of ectodermal origin, gene regulatory network (GRN) screens in conjunction with genome-wide association study-based disease phenotyping, and genetic lineage reconstruction to show that nine glial and thirty-three neuronal subtypes are generated by mid-gestation under the control of distinct GRNs. Combinatorial molecular codes that arise from neurotransmitters, neuropeptides and transcription factors are minimally required to decode the taxonomical hierarchy of hypothalamic neurons. The differentiation of γ-aminobutyric acid (GABA) and dopamine neurons, but not glutamate neurons, relies on quasi-stable intermediate states, with a pool of GABA progenitors giving rise to dopamine cells4. We found an unexpected abundance of chemotropic proliferation and guidance cues that are commonly implicated in dorsal (cortical) patterning5 in the hypothalamus. In particular, loss of SLIT-ROBO signalling impaired both the production and positioning of periventricular dopamine neurons. Overall, we identify molecular principles that shape the developmental architecture of the hypothalamus and show how neuronal heterogeneity is transformed into a multimodal neural unit to provide virtually infinite adaptive potential throughout life.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Hipotálamo/citologia , Hipotálamo/embriologia , Morfogênese , Animais , Diferenciação Celular , Linhagem da Célula , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Ectoderma/citologia , Ectoderma/metabolismo , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Ácido Glutâmico/metabolismo , Hipotálamo/metabolismo , Masculino , Camundongos , Morfogênese/genética , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Receptores Imunológicos/metabolismo , Regulon/genética , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ácido gama-Aminobutírico/metabolismo
8.
Proc Natl Acad Sci U S A ; 117(23): 12772-12783, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32467166

RESUMO

The luteinizing hormone surge is essential for fertility as it triggers ovulation in females and sperm release in males. We previously reported that secretoneurin-a, a neuropeptide derived from the processing of secretogranin-2a (Scg2a), stimulates luteinizing hormone release, suggesting a role in reproduction. Here we provide evidence that mutation of the scg2a and scg2b genes using TALENs in zebrafish reduces sexual behavior, ovulation, oviposition, and fertility. Large-scale spawning within-line crossings (n = 82 to 101) were conducted. Wild-type (WT) males paired with WT females successfully spawned in 62% of the breeding trials. Spawning success was reduced to 37% (P = 0.006), 44% (P = 0.0169), and 6% (P < 0.0001) for scg2a -/- , scg2b -/- , and scg2a -/- ;scg2b -/- mutants, respectively. Comprehensive video analysis indicates that scg2a -/- ;scg2b -/- mutation reduces all male courtship behaviors. Spawning success was 47% in saline-injected WT controls compared to 11% in saline-injected scg2a -/- ;scg2b -/- double mutants. For these mutants, spawning success increased 3-fold following a single intraperitoneal (i.p.) injection of synthetic secretoneurin-a (P = 0.0403) and increased 3.5-fold with injection of human chorionic gonadotropin (hCG). Embryonic survival at 24 h remained on average lower in scg2a -/- ;scg2b -/- fish compared to WT injected with secretoneurin-a (P < 0.001). Significant reductions in the expression of gonadotropin-releasing hormone 3 in the hypothalamus, and luteinizing hormone beta and glycoprotein alpha subunits in the pituitary provide evidence for disrupted hypothalamo-pituitary function in scg2a and scg2b mutant fish. Our results indicate that secretogranin-2 is required for optimal reproductive function and support the hypothesis that secretoneurin is a reproductive hormone.


Assuntos
Fertilidade , Preferência de Acasalamento Animal , Mutação , Secretogranina II/genética , Proteínas de Peixe-Zebra/genética , Animais , Feminino , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Neuropeptídeos/metabolismo , Oviposição , Ovulação , Hipófise/metabolismo , Secretogranina II/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
9.
PLoS Genet ; 16(5): e1008772, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32365064

RESUMO

In the postgenomics era, comparative genomics have advanced the understanding of evolutionary processes of neuropeptidergic signaling systems. The evolutionary origin of many neuropeptidergic signaling systems can be traced date back to early metazoan evolution based on the conserved sequences. Insect parathyroid hormone receptor (iPTHR) was previously described as an ortholog of vertebrate PTHR that has a well-known function in controlling bone remodeling. However, there was no sequence homologous to PTH sequence in insect genomes, leaving the iPTHR as an orphan receptor. Here, we identified the authentic ligand insect PTH (iPTH) for the iPTHR. The taxonomic distribution of iPTHR, which is lacking in Diptera and Lepidoptera, provided a lead for identifying the authentic ligand. We found that a previously described orphan ligand known as PXXXamide (where X is any amino acid) described in the cuttlefish Sepia officinalis has a similar taxonomic distribution pattern as iPTHR. Tests of this peptide, iPTH, in functional reporter assays confirmed the interaction of the ligand-receptor pair. Study of a model beetle, Tribolium castaneum, was used to investigate the function of the iPTH signaling system by RNA interference followed by RNA sequencing and phenotyping. The results suggested that the iPTH system is likely involved in the regulation of cuticle formation that culminates with a phenotype of defects in wing exoskeleton maturation at the time of adult eclosion. Moreover, RNAi of iPTHRs also led to significant reductions in egg numbers and hatching rates after parental RNAi.


Assuntos
Neuropeptídeos/metabolismo , Hormônio Paratireóideo/metabolismo , Receptores de Hormônios Paratireóideos/genética , Tribolium/anatomia & histologia , Animais , Evolução Molecular , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Fenótipo , Filogenia , Receptores de Hormônios Paratireóideos/metabolismo , Análise de Sequência de RNA , Tribolium/genética , Tribolium/metabolismo , Asas de Animais/anatomia & histologia
10.
Nat Commun ; 11(1): 2076, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350283

RESUMO

Learning and memory are regulated by neuromodulatory pathways, but the contribution and temporal requirement of most neuromodulators in a learning circuit are unknown. Here we identify the evolutionarily conserved neuromedin U (NMU) neuropeptide family as a regulator of C. elegans gustatory aversive learning. The NMU homolog CAPA-1 and its receptor NMUR-1 are required for the retrieval of learned salt avoidance. Gustatory aversive learning requires the release of CAPA-1 neuropeptides from sensory ASG neurons that respond to salt stimuli in an experience-dependent manner. Optogenetic silencing of CAPA-1 neurons blocks the expression, but not the acquisition, of learned salt avoidance. CAPA-1 signals through NMUR-1 in AFD sensory neurons to modulate two navigational strategies for salt chemotaxis. Aversive conditioning thus recruits NMU signaling to modulate locomotor programs for expressing learned avoidance behavior. Because NMU signaling is conserved across bilaterian animals, our findings incite further research into its function in other learning circuits.


Assuntos
Aprendizagem da Esquiva/fisiologia , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Rede Nervosa/fisiologia , Neuropeptídeos/metabolismo , Transdução de Sinais , Cloreto de Sódio/efeitos adversos , Paladar/fisiologia , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Comportamento Animal , Proteínas de Caenorhabditis elegans/química , Cálcio/metabolismo , Alimentos , Modelos Biológicos , Mutação/genética , Filogenia , Células Receptoras Sensoriais/fisiologia
11.
PLoS Biol ; 18(5): e3000721, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32463838

RESUMO

Dietary nutrients provide macromolecules necessary for organism growth and development. In response to animal feeding, evolutionarily conserved growth signaling pathways are activated, leading to increased rates of cell proliferation and tissue growth. It remains unclear how different cell types within developing tissues coordinate growth in response to dietary nutrients and whether coordinated growth of different cell types is necessary for proper tissue function. Here, we report that Drosophila neural stem cells, known as neuroblasts, reactivate from developmental quiescence in a dietary-nutrient-dependent manner. Neuroblast reactivation in the brain requires nonautonomous activation of phosphoinositide 3-kinase (PI3-kinase) signaling from cortex glia and tracheal processes, both of which are closely associated with neuroblasts. Furthermore, PI3-kinase activation in neuroblasts is required nonautonomously for glial membrane expansion and robust neuroblast-glial contact. Finally, PI3-kinase is required cell autonomously for nutrient-dependent growth of neuroblasts, glia, and trachea. Of the 7 Drosophila insulin-like peptides (Dilps), we find that Dilp-2 is required for PI3-kinase activation and growth coordination between neuroblasts and glia in the brain. Dilp-2 induces brain cortex glia to initiate membrane growth and make first contact with quiescent neuroblasts. After contact, neuroblasts increase in size and reenter S-phase. Once reactivated from quiescence, neuroblasts promote growth of cortex glia, which, in turn, form a selective membrane barrier around neuroblasts and their newborn progeny. Our results highlight the importance of bidirectional growth signaling between neural stem cells and surrounding cell types in the brain in response to nutrition and demonstrate how coordinated growth among different cell types drives tissue morphogenesis and function.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/crescimento & desenvolvimento , Células-Tronco Neurais/fisiologia , Neuroglia/fisiologia , Neuropeptídeos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Encéfalo/crescimento & desenvolvimento , Drosophila/enzimologia , Ingestão de Alimentos , Ativação Enzimática , Larva/crescimento & desenvolvimento , Morfogênese , Transdução de Sinais , Nicho de Células-Tronco
12.
Am J Physiol Lung Cell Mol Physiol ; 319(1): L48-L60, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32460521

RESUMO

Chronic obstructive pulmonary disease (COPD) is associated with features of accelerated aging, including cellular senescence, DNA damage, oxidative stress, and extracellular matrix (ECM) changes. We propose that these features are particularly apparent in patients with severe, early-onset (SEO)-COPD. Whether fibroblasts from COPD patients display features of accelerated aging and whether this is also present in relatively young SEO-COPD patients is unknown. Therefore, we aimed to determine markers of aging in (SEO)-COPD-derived lung fibroblasts and investigate the impact on ECM. Aging hallmarks and ECM markers were analyzed in lung fibroblasts from SEO-COPD and older COPD patients and compared with fibroblasts from matched non-COPD groups (n = 9-11 per group), both at normal culture conditions and upon Paraquat-induced senescence. COPD-related differences in senescence and ECM expression were validated in lung tissue. Higher levels of cellular senescence, including senescence-associated ß-galactosidase (SA-ß-gal)-positive cells (19% for COPD vs. 13% for control) and p16 expression, DNA damage (γ-H2A.X-positive nuclei), and oxidative stress (MGST1) were detected in COPD compared with control-derived fibroblasts. Most effects were also different in SEO-COPD, with SA-ß-gal-positive cells only being significant in SEO-COPD vs. matched controls. Lower decorin expression in COPD-derived fibroblasts correlated with higher p16 expression, and this association was confirmed in lung tissue. Paraquat treatment induced cellular senescence along with clear changes in ECM expression, including decorin. Fibroblasts from COPD patients, including SEO-COPD, display higher levels of cellular senescence, DNA damage, and oxidative stress. The association between cellular senescence and ECM expression changes may suggest a link between accelerated aging and ECM dysregulation in COPD.


Assuntos
Senescência Celular , Matriz Extracelular/metabolismo , Doença Pulmonar Obstrutiva Crônica/patologia , Adulto , Idade de Início , Biomarcadores/metabolismo , Células Cultivadas , Dano ao DNA , Feminino , Fibroblastos/patologia , Regulação da Expressão Gênica , Humanos , Pulmão/patologia , Pulmão/fisiopatologia , Masculino , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Estresse Oxidativo , Paraquat/toxicidade , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/fisiopatologia
13.
J Neurosci ; 40(19): 3720-3740, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32273484

RESUMO

Nestin, an intermediate filament protein widely used as a marker of neural progenitors, was recently found to be expressed transiently in developing cortical neurons in culture and in developing mouse cortex. In young cortical cultures, nestin regulates axonal growth cone morphology. In addition, nestin, which is known to bind the neuronal cdk5/p35 kinase, affects responses to axon guidance cues upstream of cdk5, specifically, to Sema3a. Changes in growth cone morphology require rearrangements of cytoskeletal networks, and changes in microtubules and actin filaments are well studied. In contrast, the roles of intermediate filament proteins in this process are poorly understood, even in cultured neurons. Here, we investigate the molecular mechanism by which nestin affects growth cone morphology and Sema3a sensitivity. We find that nestin selectively facilitates the phosphorylation of the lissencephaly-linked protein doublecortin (DCX) by cdk5/p35, but the phosphorylation of other cdk5 substrates is not affected by nestin. We uncover that this substrate selectivity is based on the ability of nestin to interact with DCX, but not with other cdk5 substrates. Nestin thus creates a selective scaffold for DCX with activated cdk5/p35. Last, we use cortical cultures derived from Dcx KO mice to show that the effects of nestin on growth cone morphology and on Sema3a sensitivity are DCX-dependent, thus suggesting a functional role for the DCX-nestin complex in neurons. We propose that nestin changes growth cone behavior by regulating the intracellular kinase signaling environment in developing neurons. The sex of animal subjects is unknown.SIGNIFICANCE STATEMENT Nestin, an intermediate filament protein highly expressed in neural progenitors, was recently identified in developing neurons where it regulates growth cone morphology and responsiveness to the guidance cue Sema3a. Changes in growth cone morphology require rearrangements of cytoskeletal networks, but the roles of intermediate filaments in this process are poorly understood. We now report that nestin selectively facilitates phosphorylation of the lissencephaly-linked doublecortin (DCX) by cdk5/p35, but the phosphorylation of other cdk5 substrates is not affected. This substrate selectivity is based on preferential scaffolding of DCX, cdk5, and p35 by nestin. Additionally, we demonstrate a functional role for the DCX-nestin complex in neurons. We propose that nestin changes growth cone behavior by regulating intracellular kinase signaling in developing neurons.


Assuntos
Proteínas Associadas aos Microtúbulos/metabolismo , Nestina/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Animais , Células COS , Chlorocebus aethiops , Feminino , Cones de Crescimento/metabolismo , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Semaforina-3A/metabolismo
14.
J Neurosci ; 40(21): 4219-4229, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32303647

RESUMO

In Drosophila, the mushroom bodies (MB) constitute the central brain structure for olfactory associative memory. As in mammals, the cAMP/PKA pathway plays a key role in memory formation. In the MB, Rutabaga (Rut) adenylate cyclase acts as a coincidence detector during associative conditioning to integrate calcium influx resulting from acetylcholine stimulation and G-protein activation resulting from dopaminergic stimulation. Amnesiac encodes a secreted neuropeptide required in the MB for two phases of aversive olfactory memory. Previous sequence analysis has revealed strong homology with the mammalian pituitary adenylate cyclase-activating peptide (PACAP). Here, we examined whether amnesiac is involved in cAMP/PKA dynamics in response to dopamine and acetylcholine co-stimulation in living flies. Experiments were conducted with both sexes, or with either sex. Our data show that amnesiac is necessary for the PKA activation process that results from coincidence detection in the MB. Since PACAP peptide is cleaved by the human membrane neprilysin hNEP, we searched for an interaction between Amnesiac and Neprilysin 1 (Nep1), a fly neprilysin involved in memory. We show that when Nep1 expression is acutely knocked down in adult MB, memory deficits displayed by amn hypomorphic mutants are rescued. Consistently, Nep1 inhibition also restores normal PKA activation in amn mutant flies. Taken together, the results suggest that Nep1 targets Amnesiac degradation to terminate its signaling function. Our work thus highlights a key role for Amnesiac in establishing within the MB the PKA dynamics that sustain middle-term memory (MTM) formation, a function modulated by Nep1.SIGNIFICANCE STATEMENT The Drosophila amnesiac gene encodes a secreted neuropeptide whose expression is required for specific memory phases in the mushroom bodies (MB), the olfactory memory center. Here, we show that Amnesiac is required for PKA activation resulting from coincidence detection, a mechanism by which the MB integrate two spatially distinct stimuli to encode associative memory. Furthermore, our results uncover a functional relationship between Amnesiac and Neprilysin 1 (Nep1), a membrane peptidase involved in memory and expressed in the MB. These results suggest that Nep1 modulates Amnesiac levels. We propose that on conditioning, Amnesiac release from the MB allows, via an autocrine process, the sustaining of PKA activation-mediating memory, which subsequently is inactivated by Nep1 degradation.


Assuntos
Aprendizagem da Esquiva/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Drosophila/genética , Memória/fisiologia , Corpos Pedunculados/metabolismo , Neprilisina/metabolismo , Neuropeptídeos/genética , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Neuropeptídeos/metabolismo , Olfato/fisiologia
15.
Proc Natl Acad Sci U S A ; 117(13): 7401-7408, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32179671

RESUMO

The intake of macronutrients is crucial for the fitness of any animal and is mainly regulated by peripheral signals to the brain. How the brain receives and translates these peripheral signals or how these interactions lead to changes in feeding behavior is not well-understood. We discovered that 2 crustacean cardioactive peptide (CCAP)-expressing neurons in Drosophila adults regulate feeding behavior and metabolism. Notably, loss of CCAP, or knocking down the CCAP receptor (CCAP-R) in 2 dorsal median neurons, inhibits the release of neuropeptide F (NPF), which regulates feeding behavior. Furthermore, under starvation conditions, flies normally have an increased sensitivity to sugar; however, loss of CCAP, or CCAP-R in 2 dorsal median NPF neurons, inhibited sugar sensitivity in satiated and starved flies. Separate from its regulation of NPF signaling, the CCAP peptide also regulates triglyceride levels. Additionally, genetic and optogenetic studies demonstrate that CCAP signaling is necessary and sufficient to stimulate a reflexive feeding behavior, the proboscis extension reflex (PER), elicited when external food cues are interpreted as palatable. Dopaminergic signaling was also sufficient to induce a PER. On the other hand, although necessary, NPF neurons were not able to induce a PER. These data illustrate that the CCAP peptide is a central regulator of feeding behavior and metabolism in adult flies, and that NPF neurons have an important regulatory role within this system.


Assuntos
Comportamento Alimentar/fisiologia , Neuropeptídeos/metabolismo , Animais , Encéfalo/metabolismo , Ritmo Circadiano/fisiologia , Dopamina/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Neurônios/metabolismo , Neuropeptídeos/genética , Transdução de Sinais , Inanição/metabolismo
16.
Proc Natl Acad Sci U S A ; 117(13): 7447-7454, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32165542

RESUMO

Acid-sensing ion channels (ASICs) are proton-gated cation channels that contribute to neurotransmission, as well as initiation of pain and neuronal death following ischemic stroke. As such, there is a great interest in understanding the in vivo regulation of ASICs, especially by endogenous neuropeptides that potently modulate ASICs. The most potent endogenous ASIC modulator known to date is the opioid neuropeptide big dynorphin (BigDyn). BigDyn is up-regulated in chronic pain and increases ASIC-mediated neuronal death during acidosis. Understanding the mechanism and site of action of BigDyn on ASICs could thus enable the rational design of compounds potentially useful in the treatment of pain and ischemic stroke. To this end, we employ a combination of electrophysiology, voltage-clamp fluorometry, synthetic BigDyn analogs, and noncanonical amino acid-mediated photocrosslinking. We demonstrate that BigDyn binding results in an ASIC1a closed resting conformation that is distinct from open and desensitized states induced by protons. Using alanine-substituted BigDyn analogs, we find that the BigDyn modulation of ASIC1a is primarily mediated through electrostatic interactions of basic amino acids in the BigDyn N terminus. Furthermore, neutralizing acidic amino acids in the ASIC1a extracellular domain reduces BigDyn effects, suggesting a binding site at the acidic pocket. This is confirmed by photocrosslinking using the noncanonical amino acid azidophenylalanine. Overall, our data define the mechanism of how BigDyn modulates ASIC1a, identify the acidic pocket as the binding site for BigDyn, and thus highlight this cavity as an important site for the development of ASIC-targeting therapeutics.


Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Dinorfinas/metabolismo , Canais Iônicos Sensíveis a Ácido/genética , Animais , Animais Geneticamente Modificados , Sítios de Ligação , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Neuropeptídeos/fisiologia , Oócitos/metabolismo , Prótons , Xenopus laevis
17.
PLoS Genet ; 16(3): e1008270, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32160200

RESUMO

Sleep is a nearly universal behavior that is regulated by diverse environmental stimuli and physiological states. A defining feature of sleep is a homeostatic rebound following deprivation, where animals compensate for lost sleep by increasing sleep duration and/or sleep depth. The fruit fly, Drosophila melanogaster, exhibits robust recovery sleep following deprivation and represents a powerful model to study neural circuits regulating sleep homeostasis. Numerous neuronal populations have been identified in modulating sleep homeostasis as well as depth, raising the possibility that the duration and quality of recovery sleep is dependent on the environmental or physiological processes that induce sleep deprivation. Here, we find that unlike most pharmacological and environmental manipulations commonly used to restrict sleep, starvation potently induces sleep loss without a subsequent rebound in sleep duration or depth. Both starvation and a sucrose-only diet result in increased sleep depth, suggesting that dietary protein is essential for normal sleep depth and homeostasis. Finally, we find that Drosophila insulin like peptide 2 (Dilp2) is acutely required for starvation-induced changes in sleep depth without regulating the duration of sleep. Flies lacking Dilp2 exhibit a compensatory sleep rebound following starvation-induced sleep deprivation, suggesting Dilp2 promotes resiliency to sleep loss. Together, these findings reveal innate resilience to starvation-induced sleep loss and identify distinct mechanisms that underlie starvation-induced changes in sleep duration and depth.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Insulina/metabolismo , Neuropeptídeos/metabolismo , Sono/fisiologia , Animais , Dieta/métodos , Privação do Sono/metabolismo , Inanição/metabolismo
18.
PLoS Biol ; 18(3): e3000614, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32126082

RESUMO

The reproductive hormones that trigger oocyte meiotic maturation and release from the ovary vary greatly between animal species. Identification of receptors for these maturation-inducing hormones (MIHs) and understanding how they initiate the largely conserved maturation process remain important challenges. In hydrozoan cnidarians including the jellyfish Clytia hemisphaerica, MIH comprises neuropeptides released from somatic cells of the gonad. We identified the receptor (MIHR) for these MIH neuropeptides in Clytia using cell culture-based "deorphanization" of candidate oocyte-expressed G protein-coupled receptors (GPCRs). MIHR mutant jellyfish generated using CRISPR-Cas9 editing had severe defects in gamete development or in spawning both in males and females. Female gonads, or oocytes isolated from MIHR mutants, failed to respond to synthetic MIH. Treatment with the cAMP analogue Br-cAMP to mimic cAMP rise at maturation onset rescued meiotic maturation and spawning. Injection of inhibitory antibodies to the alpha subunit of the Gs heterodimeric protein (GαS) into wild-type oocytes phenocopied the MIHR mutants. These results provide the molecular links between MIH stimulation and meiotic maturation initiation in hydrozoan oocytes. Molecular phylogeny grouped Clytia MIHR with a subset of bilaterian neuropeptide receptors, including neuropeptide Y, gonadotropin inhibitory hormone (GnIH), pyroglutamylated RFamide, and luqin, all upstream regulators of sexual reproduction. This identification and functional characterization of a cnidarian peptide GPCR advances our understanding of oocyte maturation initiation and sheds light on the evolution of neuropeptide-hormone systems.


Assuntos
Hidrozoários/fisiologia , Neuropeptídeos/metabolismo , Oócitos/fisiologia , Receptores Acoplados a Proteínas-G/metabolismo , Animais , Animais Geneticamente Modificados , Sistemas CRISPR-Cas , AMP Cíclico/metabolismo , Feminino , Expressão Gênica , Hidrozoários/genética , Masculino , Mutação , Filogenia , Receptores Acoplados a Proteínas-G/genética , Receptores de Neuropeptídeos/genética , Receptores de Neuropeptídeos/metabolismo
19.
Immunity ; 52(3): 464-474, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32187517

RESUMO

The ability of the nervous system to sense environmental stimuli and to relay these signals to immune cells via neurotransmitters and neuropeptides is indispensable for effective immunity and tissue homeostasis. Depending on the tissue microenvironment and distinct drivers of a certain immune response, the same neuronal populations and neuro-mediators can exert opposing effects, promoting or inhibiting tissue immunity. Here, we review the current understanding of the mechanisms that underlie the complex interactions between the immune and the nervous systems in different tissues and contexts. We outline current gaps in knowledge and argue for the importance of considering infectious and inflammatory disease within a conceptual framework that integrates neuro-immune circuits both local and systemic, so as to better understand effective immunity to develop improved approaches to treat inflammation and disease.


Assuntos
Sistema Imunitário/imunologia , Sistema Nervoso/imunologia , Neuroimunomodulação/imunologia , Neurônios/imunologia , Animais , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/metabolismo , Imunidade Inata/imunologia , Sistema Nervoso/citologia , Sistema Nervoso/metabolismo , Inflamação Neurogênica/imunologia , Inflamação Neurogênica/metabolismo , Neurônios/metabolismo , Neuropeptídeos/imunologia , Neuropeptídeos/metabolismo , Transdução de Sinais/imunologia
20.
Nat Commun ; 11(1): 1450, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193370

RESUMO

Olfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.


Assuntos
Comportamento Alimentar/fisiologia , Metabolismo dos Lipídeos/fisiologia , Sistemas Neurossecretores/metabolismo , Obesidade/metabolismo , Percepção Olfatória/fisiologia , Animais , Animais Geneticamente Modificados , Butanonas/química , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Odorantes , Optogenética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Neuropeptídeos/metabolismo
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