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1.
Nat Commun ; 12(1): 5462, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526503

RESUMO

Salicylic acid is a phenolic phytohormone which controls plant growth and development. A methyl ester (MSA) derivative thereof is volatile and involved in plant-insect or plant-plant communication. Here we show that the nematode-trapping fungus Duddingtonia flagrans uses a methyl-salicylic acid isomer, 6-MSA as morphogen for spatiotemporal control of trap formation and as chemoattractant to lure Caenorhabditis elegans into fungal colonies. 6-MSA is the product of a polyketide synthase and an intermediate in the biosynthesis of arthrosporols. The polyketide synthase (ArtA), produces 6-MSA in hyphal tips, and is uncoupled from other enzymes required for the conversion of 6-MSA to arthrosporols, which are produced in older hyphae. 6-MSA and arthrosporols both block trap formation. The presence of nematodes inhibits 6-MSA and arthrosporol biosyntheses and thereby enables trap formation. 6-MSA and arthrosporols are thus morphogens with some functions similar to quorum-sensing molecules. We show that 6-MSA is important in interkingdom communication between fungi and nematodes.


Assuntos
Ascomicetos/fisiologia , Caenorhabditis elegans/fisiologia , Hifas/fisiologia , Comportamento Predatório/fisiologia , Ácido Salicílico/metabolismo , Animais , Ascomicetos/genética , Ascomicetos/metabolismo , Quimiotaxia/fisiologia , Proteínas Fúngicas/metabolismo , Hifas/genética , Hifas/metabolismo , Policetídeo Sintases/metabolismo , Ácido Salicílico/química , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismo
3.
Nat Commun ; 12(1): 5519, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34535659

RESUMO

Since the variables inherent to various diseases cannot be controlled directly in humans, behavioral dysfunctions have been examined in model organisms, leading to better understanding their underlying mechanisms. However, because the spatial and temporal scales of animal locomotion vary widely among species, conventional statistical analyses cannot be used to discover knowledge from the locomotion data. We propose a procedure to automatically discover locomotion features shared among animal species by means of domain-adversarial deep neural networks. Our neural network is equipped with a function which explains the meaning of segments of locomotion where the cross-species features are hidden by incorporating an attention mechanism into the neural network, regarded as a black box. It enables us to formulate a human-interpretable rule about the cross-species locomotion feature and validate it using statistical tests. We demonstrate the versatility of this procedure by identifying locomotion features shared across different species with dopamine deficiency, namely humans, mice, and worms, despite their evolutionary differences.


Assuntos
Atenção , Comportamento Animal , Redes Neurais de Computação , Animais , Atenção/fisiologia , Caenorhabditis elegans/fisiologia , Besouros/fisiologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Humanos , Camundongos Endogâmicos C57BL , Doença de Parkinson/patologia , Especificidade da Espécie
4.
Elife ; 102021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34467850

RESUMO

Mitochondrial activity determines aging rate and the onset of chronic diseases. The mitochondrial permeability transition pore (mPTP) is a pathological pore in the inner mitochondrial membrane thought to be composed of the F-ATP synthase (complex V). OSCP, a subunit of F-ATP synthase, helps protect against mPTP formation. How the destabilization of OSCP may contribute to aging, however, is unclear. We have found that loss OSCP in the nematode Caenorhabditis elegans initiates the mPTP and shortens lifespan specifically during adulthood, in part via initiation of the mitochondrial unfolded protein response (UPRmt). Pharmacological or genetic inhibition of the mPTP inhibits the UPRmt and restores normal lifespan. Loss of the putative pore-forming component of F-ATP synthase extends adult lifespan, suggesting that the mPTP normally promotes aging. Our findings reveal how an mPTP/UPRmt nexus may contribute to aging and age-related diseases and how inhibition of the UPRmt may be protective under certain conditions.


Assuntos
Envelhecimento , Caenorhabditis elegans/fisiologia , Membranas Mitocondriais/fisiologia , Poro de Transição de Permeabilidade Mitocondrial/metabolismo , Resposta a Proteínas não Dobradas , Animais , Mitocôndrias/fisiologia
5.
Nat Commun ; 12(1): 4947, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400648

RESUMO

Phase separation at the molecular scale affects many biological processes. The theoretical requirements for phase separation are fairly minimal, and there is growing evidence that analogous phenomena occur at other scales in biology. Here we examine colony formation in the nematode C. elegans as a possible example of phase separation by a population of organisms. The population density of worms determines whether a colony will form in a thresholded fashion, and a simple two-compartment ordinary differential equation model correctly predicts the threshold. Furthermore, small, round colonies sometimes fuse to form larger, round colonies, and a phenomenon akin to Ostwald ripening - a coarsening process seen in many systems that undergo phase separation - also occurs. These findings support the emerging view that the principles of microscopic phase separation can also apply to collective behaviors of living organisms.


Assuntos
Fenômenos Biológicos , Caenorhabditis elegans/fisiologia , Animais , Bactérias , Comportamento Animal , Quimiotaxia , Modelos Biológicos , Comportamento Social
6.
Nat Commun ; 12(1): 4795, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373460

RESUMO

Chemogenetic and optogenetic tools have transformed the field of neuroscience by facilitating the examination and manipulation of existing circuits. Yet, the field lacks tools that enable rational rewiring of circuits via the creation or modification of synaptic relationships. Here we report the development of HySyn, a system designed to reconnect neural circuits in vivo by reconstituting synthetic modulatory neurotransmission. We demonstrate that genetically targeted expression of the two HySyn components, a Hydra-derived neuropeptide and its receptor, creates de novo neuromodulatory transmission in a mammalian neuronal tissue culture model and functionally rewires a behavioral circuit in vivo in the nematode Caenorhabditis elegans. HySyn can interface with existing optogenetic, chemogenetic and pharmacological approaches to functionally probe synaptic transmission, dissect neuropeptide signaling, or achieve targeted modulation of specific neural circuits and behaviors.


Assuntos
Neurônios/fisiologia , Transmissão Sináptica/genética , Transmissão Sináptica/fisiologia , Animais , Comportamento Animal/fisiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Cálcio , Expressão Gênica , Técnicas Genéticas , Hydra/genética , Hydra/fisiologia , Vias Neurais/fisiologia , Neuropeptídeos , Optogenética , Transdução de Sinais
7.
Int J Mol Sci ; 22(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34445171

RESUMO

Tauopathy refers to a group of progressive neurodegenerative diseases, including frontotemporal lobar degeneration and Alzheimer's disease, which correlate with the malfunction of microtubule-associated protein Tau (MAPT) due to abnormal hyperphosphorylation, leading to the formation of intracellular aggregates in the brain. Despite extensive efforts to understand tauopathy and develop an efficient therapy, our knowledge is still far from complete. To find a solution for this group of devastating diseases, several animal models that mimic diverse disease phenotypes of tauopathy have been developed. Rodents are the dominating tauopathy models because of their similarity to humans and established disease lines, as well as experimental approaches. However, powerful genetic animal models using Drosophila, zebrafish, and C. elegans have also been developed for modeling tauopathy and have contributed to understanding the pathophysiology of tauopathy. The success of these models stems from the short lifespans, versatile genetic tools, real-time in-vivo imaging, low maintenance costs, and the capability for high-throughput screening. In this review, we summarize the main findings on mechanisms of tauopathy and discuss the current tauopathy models of these non-rodent genetic animals, highlighting their key advantages and limitations in tauopathy research.


Assuntos
Modelos Animais de Doenças , Tauopatias/genética , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Drosophila/genética , Drosophila/fisiologia , Humanos , Tauopatias/fisiopatologia , Peixe-Zebra/genética , Peixe-Zebra/fisiologia , Proteínas tau/genética
8.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443430

RESUMO

Parkinson's disease (PD) is a currently incurable neurodegenerative disorder characterized by the loss of dopaminergic (DAergic) neurons in the substantia nigra pars compacta and α-synuclein aggregation. Accumulated evidence indicates that the saponins, especially from ginseng, have neuroprotective effects against neurodegenerative disorders. Interestingly, saponin can also be found in marine organisms such as the sea cucumber, but little is known about its effect in neurodegenerative disease, including PD. In this study, we investigated the anti-Parkinson effects of frondoside A (FA) from Cucumaria frondosa and ginsenoside Rg3 (Rg3) from Panax notoginseng in C. elegans PD model. Both saponins were tested for toxicity and optimal concentration by food clearance assay and used to treat 6-OHDA-induced BZ555 and transgenic α-synuclein NL5901 strains in C. elegans. Treatment with FA and Rg3 significantly attenuated DAergic neurodegeneration induced by 6-OHDA in BZ555 strain, improved basal slowing rate, and prolonged lifespan in the 6-OHDA-induced wild-type strain with downregulation of the apoptosis mediators, egl-1 and ced-3, and upregulation of sod-3 and cat-2. Interestingly, only FA reduced α-synuclein aggregation, rescued lifespan in NL5901, and upregulated the protein degradation regulators, including ubh-4, hsf-1, hsp-16.1 and hsp-16.2. This study indicates that both FA and Rg3 possess beneficial effects in rescuing DAergic neurodegeneration in the 6-OHDA-induced C. elegans model through suppressing apoptosis mediators and stimulating antioxidant enzymes. In addition, FA could attenuate α-synuclein aggregation through the protein degradation process.


Assuntos
Caenorhabditis elegans/fisiologia , Ginsenosídeos/farmacologia , Glicosídeos/farmacologia , Doença de Parkinson/patologia , Triterpenos/farmacologia , Animais , Animais Geneticamente Modificados , Apoptose/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Ginsenosídeos/química , Ginsenosídeos/toxicidade , Glicosídeos/química , Glicosídeos/toxicidade , Longevidade/efeitos dos fármacos , Degeneração Neural/complicações , Degeneração Neural/patologia , Oxidopamina , Doença de Parkinson/complicações , Proteólise/efeitos dos fármacos , Triterpenos/química , Triterpenos/toxicidade , alfa-Sinucleína/metabolismo
9.
Development ; 148(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34338279

RESUMO

The conserved exocyst complex regulates plasma membrane-directed vesicle fusion in eukaryotes. However, its role in stem cell proliferation has not been reported. Germline stem cell (GSC) proliferation in the nematode Caenorhabditis elegans is regulated by conserved Notch signaling. Here, we reveal that the exocyst complex regulates C. elegans GSC proliferation by modulating Notch signaling cell autonomously. Notch membrane density is asymmetrically maintained on GSCs. Knockdown of exocyst complex subunits or of the exocyst-interacting GTPases Rab5 and Rab11 leads to Notch redistribution from the GSC-niche interface to the cytoplasm, suggesting defects in plasma membrane Notch deposition. The anterior polarity (aPar) protein Par6 is required for GSC proliferation, and for maintaining niche-facing membrane levels of Notch and the exocyst complex. The exocyst complex biochemically interacts with the aPar regulator Par5 (14-3-3ζ) and Notch in C. elegans and human cells. Exocyst components are required for Notch plasma membrane localization and signaling in mammalian cells. Our study uncovers a possibly conserved requirement of the exocyst complex in regulating GSC proliferation and in maintaining optimal membrane Notch levels.


Assuntos
Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Membrana Celular/metabolismo , Proliferação de Células/fisiologia , Células Germinativas/metabolismo , Células Germinativas/fisiologia , Nicho de Células-Tronco/fisiologia , Proteínas 14-3-3/metabolismo , Animais , Proteínas de Caenorhabditis elegans/metabolismo , Comunicação Celular/fisiologia , Membrana Celular/fisiologia , Citoplasma/metabolismo , Citoplasma/fisiologia , Eucariotos/metabolismo , Eucariotos/fisiologia , Fusão de Membrana/fisiologia , Morfogênese/fisiologia , Transdução de Sinais/fisiologia
10.
Elife ; 102021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34388088

RESUMO

Neuronal cell fate determinants establish the identities of neurons by controlling gene expression to regulate neuronal morphology and synaptic connectivity. However, it is not understood if neuronal cell fate determinants have postmitotic functions in synapse pattern formation. Here we identify a novel role for UNC-4 homeobox protein and its corepressor UNC-37/Groucho, in tiled synaptic patterning of the cholinergic motor neurons in Caenorhabditis elegans. We show that unc-4 is not required during neurogenesis but is required in the postmitotic neurons for proper synapse patterning. In contrast, unc-37 is required in both developing and postmitotic neurons. The synaptic tiling defects of unc-4 mutants are suppressed by bar-1/ß-catenin mutation, which positively regulates the expression of ceh-12/HB9. Ectopic ceh-12 expression partly underlies the synaptic tiling defects of unc-4 and unc-37 mutants. Our results reveal a novel postmitotic role of neuronal cell fate determinants in synapse pattern formation through inhibiting the canonical Wnt signaling pathway.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Expressão Gênica , Genes Homeobox , Proteínas de Homeodomínio/genética , Fatores de Transcrição/genética , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas Correpressoras/genética , Proteínas de Homeodomínio/metabolismo , Mitose , Neurônios/fisiologia , Sinapses/fisiologia , Fatores de Transcrição/metabolismo
11.
Nat Commun ; 12(1): 5073, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417467

RESUMO

The contents of numerous membrane lipids change upon ageing. However, it is unknown whether and how any of these changes are causally linked to lifespan regulation. Acyl chains contribute to the functional specificity of membrane lipids. In this study, working with C. elegans, we identified an acyl chain-specific sphingolipid, C22 glucosylceramide, as a longevity metabolite. Germline deficiency, a conserved lifespan-extending paradigm, induces somatic expression of the fatty acid elongase ELO-3, and behenic acid (22:0) generated by ELO-3 is incorporated into glucosylceramide for lifespan regulation. Mechanistically, C22 glucosylceramide is required for the membrane localization of clathrin, a protein that regulates membrane budding. The reduction in C22 glucosylceramide impairs the clathrin-dependent autophagic lysosome reformation, which subsequently leads to TOR activation and longevity suppression. These findings reveal a mechanistic link between membrane lipids and ageing and suggest a model of lifespan regulation by fatty acid-mediated membrane configuration.


Assuntos
Caenorhabditis elegans/fisiologia , Ácidos Graxos não Esterificados/metabolismo , Glicoesfingolipídeos/metabolismo , Homeostase , Longevidade/fisiologia , Lisossomos/metabolismo , Animais , Proteínas de Caenorhabditis elegans/metabolismo , Ceramidas/metabolismo , Colesterol/metabolismo , Clatrina/metabolismo , Mutação em Linhagem Germinativa/genética , Proteínas de Fluorescência Verde/metabolismo , Larva/metabolismo , Modelos Biológicos , Interferência de RNA , Estresse Fisiológico
12.
Nutrients ; 13(8)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34444677

RESUMO

Caffeine, a methylxanthine derived from plants, is the most widely consumed ingredient in daily life. Therefore, it is necessary to investigate the effects of caffeine intake on essential biological activities. In this study, we attempted to determine the possible anti-aging effects of long-term caffeine intake in the intestine of an aged Caenorhabditis elegans model. We examined changes in intestinal integrity, production of vitellogenin (VIT), and mitochondrial function after caffeine intake. To evaluate intestinal aging, actin-5 (ACT-5) mislocalization, lumenal expansion, and intestinal colonization were examined after caffeine intake, and the levels of vitellogenesis as well as the mitochondrial activity were measured. We found that the long-term caffeine intake (10 mM) in the L4-stage worms at 25 °C for 3 days suppressed ACT-5 mislocalization. Furthermore, the level of autophagy, which is normally increased in aging animals, was significantly reduced in these animals, and their mitochondrial functions improved after caffeine intake. In addition, the caffeine-ingesting aging animals showed high resistance to oxidative stress and increased the expression of antioxidant proteins. Taken together, these findings reveal that caffeine may be a potential anti-aging agent that can suppress intestinal atrophy during the progression of intestinal aging.


Assuntos
Envelhecimento/fisiologia , Caenorhabditis elegans/fisiologia , Cafeína/administração & dosagem , Intestinos/fisiologia , Mitocôndrias/fisiologia , Vitelogênese/efeitos dos fármacos , Actinas/análise , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/efeitos dos fármacos , Intestinos/ultraestrutura , Mitocôndrias/efeitos dos fármacos , Modelos Animais , Estresse Oxidativo/efeitos dos fármacos
13.
Nat Commun ; 12(1): 4336, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34267196

RESUMO

Glutathione (GSH) is the most abundant cellular antioxidant. As reactive oxygen species (ROS) are widely believed to promote aging and age-related diseases, and antioxidants can neutralize ROS, it follows that GSH and its precursor, N-acetyl cysteine (NAC), are among the most popular dietary supplements. However, the long- term effects of GSH or NAC on healthy animals have not been thoroughly investigated. We employed C. elegans to demonstrate that chronic administration of GSH or NAC to young or aged animals perturbs global gene expression, inhibits skn-1-mediated transcription, and accelerates aging. In contrast, limiting the consumption of dietary thiols, including those naturally derived from the microbiota, extended lifespan. Pharmacological GSH restriction activates the unfolded protein response and increases proteotoxic stress resistance in worms and human cells. It is thus advantageous for healthy individuals to avoid excessive dietary antioxidants and, instead, rely on intrinsic GSH biosynthesis, which is fine-tuned to match the cellular redox status and to promote homeostatic ROS signaling.


Assuntos
Acetilcisteína/farmacologia , Envelhecimento/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Glutationa/farmacologia , Envelhecimento/genética , Envelhecimento/fisiologia , Animais , Animais Geneticamente Modificados , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/genética , Suplementos Nutricionais , Escherichia coli , Feminino , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Masculino , Paraquat/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Compostos de Sulfidrila/metabolismo , Fatores de Transcrição/genética , Resposta a Proteínas não Dobradas/fisiologia
14.
Elife ; 102021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34227470

RESUMO

Foraging animals have to locate food sources that are usually patchily distributed and subject to competition. Deciding when to leave a food patch is challenging and requires the animal to integrate information about food availability with cues signaling the presence of other individuals (e.g., pheromones). To study how social information transmitted via pheromones can aid foraging decisions, we investigated the behavioral responses of the model animal Caenorhabditis elegans to food depletion and pheromone accumulation in food patches. We experimentally show that animals consuming a food patch leave it at different times and that the leaving time affects the animal preference for its pheromones. In particular, worms leaving early are attracted to their pheromones, while worms leaving later are repelled by them. We further demonstrate that the inversion from attraction to repulsion depends on associative learning and, by implementing a simple model, we highlight that it is an adaptive solution to optimize food intake during foraging.


Assuntos
Caenorhabditis elegans/fisiologia , Feromônios/metabolismo , Animais , Comportamento Alimentar
15.
Nature ; 596(7871): 281-284, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34290409

RESUMO

The mTOR complex 1 (mTORC1) controls cell growth in response to amino acid levels1. Here we report SAR1B as a leucine sensor that regulates mTORC1 signalling in response to intracellular levels of leucine. Under conditions of leucine deficiency, SAR1B inhibits mTORC1 by physically targeting its activator GATOR2. In conditions of leucine sufficiency, SAR1B binds to leucine, undergoes a conformational change and dissociates from GATOR2, which results in mTORC1 activation. SAR1B-GATOR2-mTORC1 signalling is conserved in nematodes and has a role in the regulation of lifespan. Bioinformatic analysis reveals that SAR1B deficiency correlates with the development of lung cancer. The silencing of SAR1B and its paralogue SAR1A promotes mTORC1-dependent growth of lung tumours in mice. Our results reveal that SAR1B is a conserved leucine sensor that has a potential role in the development of lung cancer.


Assuntos
Leucina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Transdução de Sinais , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Sequência Conservada , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Células HEK293 , Humanos , Leucina/deficiência , Longevidade/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/agonistas , Camundongos , Proteínas Monoméricas de Ligação ao GTP/química , Proteínas Monoméricas de Ligação ao GTP/deficiência , Proteínas Monoméricas de Ligação ao GTP/genética , Complexos Multiproteicos/metabolismo , Proteínas Nucleares/metabolismo , Ligação Proteica , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Elife ; 102021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34323215

RESUMO

The translation initiation complex eIF3 imparts specialized functions to regulate protein expression. However, understanding of eIF3 activities in neurons remains limited despite widespread dysregulation of eIF3 subunits in neurological disorders. Here, we report a selective role of the C. elegans RNA-binding subunit EIF-3.G in shaping the neuronal protein landscape. We identify a missense mutation in the conserved Zinc-Finger (ZF) of EIF-3.G that acts in a gain-of-function manner to dampen neuronal hyperexcitation. Using neuron-type-specific seCLIP, we systematically mapped EIF-3.G-mRNA interactions and identified EIF-3.G occupancy on GC-rich 5'UTRs of a select set of mRNAs enriched in activity-dependent functions. We demonstrate that the ZF mutation in EIF-3.G alters translation in a 5'UTR-dependent manner. Our study reveals an in vivo mechanism for eIF3 in governing neuronal protein levels to control neuronal activity states and offers insights into how eIF3 dysregulation contributes to neurological disorders.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Fator de Iniciação 3 em Eucariotos/genética , Neurônios/fisiologia , Biossíntese de Proteínas , RNA de Helmintos/biossíntese , RNA Mensageiro/biossíntese , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fator de Iniciação 3 em Eucariotos/metabolismo
17.
Nat Commun ; 12(1): 4568, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315882

RESUMO

Insulin/IGF-1 Signaling (IIS) is known to constrain longevity by inhibiting the transcription factor FOXO. How phosphorylation mediated by IIS kinases regulates lifespan beyond FOXO remains unclear. Here, we profile IIS-dependent phosphorylation changes in a large-scale quantitative phosphoproteomic analysis of wild-type and three IIS mutant Caenorhabditis elegans strains. We quantify more than 15,000 phosphosites and find that 476 of these are differentially phosphorylated in the long-lived daf-2/insulin receptor mutant. We develop a machine learning-based method to prioritize 25 potential lifespan-related phosphosites. We perform validations to show that AKT-1 pT492 inhibits DAF-16/FOXO and compensates the loss of daf-2 function, that EIF-2α pS49 potently inhibits protein synthesis and daf-2 longevity, and that reduced phosphorylation of multiple germline proteins apparently transmits reduced DAF-2 signaling to the soma. In addition, an analysis of kinases with enriched substrates detects that casein kinase 2 (CK2) subunits negatively regulate lifespan. Our study reveals detailed functional insights into longevity.


Assuntos
Caenorhabditis elegans/fisiologia , Insulina/metabolismo , Longevidade/fisiologia , Transdução de Sinais , Algoritmos , Sequência de Aminoácidos , Animais , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/metabolismo , Células Germinativas/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Modelos Biológicos , Mutação/genética , Fosfoproteínas/metabolismo , Fosforilação , Proteoma/metabolismo , Proteômica
18.
Phytomedicine ; 88: 153598, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111615

RESUMO

INTRODUCTION: Depression is one of the leading causes of death worldwide. Lower antioxidant concentrations and increased oxidative stress levels contribute to the development of depression. Effective and tolerable medications are urgently needed. Nrf2 and PRDX2 are promising targets in the treatment of oxidative stress and, therefore, promising for the development of novel antidepressants. Ursolic acid (UA), a natural triterpenoid found in various plants is known to exert neuroprotective and antioxidant effects. Skn-1 (which corresponds to human Nrf2) and prdx2 deficient mutants of the nematode Caenorhabditis elegans are suitable models to study the effect of UA on these targets. Additionally, stress assays are used to mimic stress or depressed state. METHODS: We examined the antioxidant activity of UA in Caenorhabditis elegans wildtype and skn-1- and prdx2-deficient strains by H2DCF-DA and juglone assays as well as osmotic and heat stress assays. Additionally, we analyzed the binding of UA to human PRDX2 and Skn-1 proteins by molecular docking and microscale thermophoresis. RESULTS: UA exerted strong antioxidant activities. Additionally, induction of stress resistance towards osmotic and heat stress was observed. qRT-PCR revealed that UA upregulated the gene expression of skn-1 and prdx2. Molecular docking studies supported these findings. CONCLUSION: Our findings implicate that the strong antioxidant activity of UA may exert anti-depressive effects by its interaction with the Skn-1 transcription factor, which is part of a detoxification network, and the antioxidant PRDX2 protein, which protects the organism from the detrimental effects of radical oxygen species.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Depressão/genética , Estresse Fisiológico/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Antidepressivos/farmacologia , Antioxidantes/farmacologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Simulação de Acoplamento Molecular , Mutação , Estresse Oxidativo/efeitos dos fármacos , Peroxirredoxinas/genética , Substâncias Protetoras/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genética , Triterpenos/química
19.
Methods Mol Biol ; 2326: 19-32, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34097258

RESUMO

The contamination of heavy metals, a class of naturally occurring and persistent toxicants, has become a major public health concern due to increasing industrial and anthropogenic activities. The use of COPAS Biosort, a flow cytometer capable of measuring thousands of nematodes in minutes via high-throughput assays, has been widely applied in C. elegans studies for assessing toxicity of individual metals; however, such application yet to be seen for metals or other chemical mixtures. In the present protocol, we investigated toxic effects of individual metals, Cd, Pb, and Mn, as well as their binary and ternary mixtures, using nematode C. elegans. The toxic outcomes, including effects on growth, reproduction, and feeding behavior, were measured using high-throughput platform analysis (COAPS Biosort).


Assuntos
Cádmio/toxicidade , Caenorhabditis elegans/efeitos dos fármacos , Chumbo/toxicidade , Manganês/toxicidade , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Ensaios de Triagem em Larga Escala/métodos , Reprodução/efeitos dos fármacos , Testes de Toxicidade/métodos
20.
Elife ; 102021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34184985

RESUMO

Sterile alpha and toll/interleukin receptor (TIR) motif-containing protein 1 (SARM1) is a neuronally expressed NAD+ glycohydrolase whose activity is increased in response to stress. NAD+ depletion triggers axonal degeneration, which is a characteristic feature of neurological diseases. Notably, loss of SARM1 is protective in murine models of peripheral neuropathy and traumatic brain injury. Herein, we report that citrate induces a phase transition that enhances SARM1 activity by ~2000-fold. This phase transition can be disrupted by mutating a residue involved in multimerization, G601P. This mutation also disrupts puncta formation in cells. We further show that citrate induces axonal degeneration in C. elegans that is dependent on the C. elegans orthologue of SARM1 (TIR-1). Notably, citrate induces the formation of larger puncta indicating that TIR-1/SARM1 multimerization is essential for degeneration in vivo. These findings provide critical insights into SARM1 biology with important implications for the discovery of novel SARM1-targeted therapeutics.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/efeitos dos fármacos , Ácido Cítrico/administração & dosagem , NAD+ Nucleosidase/genética , Transição de Fase , Receptores Acoplados a Proteínas G/genética , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/metabolismo , NAD+ Nucleosidase/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
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