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1.
Toxicol Lett ; 334: 102-109, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33002525

RESUMO

Beauvericin is an ubiquitous mycotoxin with relevant occurrence in food and feed. It causes a high toxicity in several cell lines, but its general mechanism of action is not fully understood and only limited in vivo studies have been performed. We used Caenorhabditis elegans as a model organism to investigate effects of beauvericin. The mycotoxin displays a moderate acute toxicity at 100 µM; at this concentration also reproductive toxicity occurred (reduction of total progeny to 32.1 %), developmental toxicity was detectable at 250 µM. However, even lower concentrations were capable to reduce stress resistance and life span of the nematode: A significant reduction was detected at 10 µM beauvericin (decrease in mean survival time of 4.3 % and reduction in life span of 12.9 %). An increase in lipofuscin fluorescence was demonstrated starting at 10 µM suggesting oxidative stress as a mechanism of beauvericin toxicity. Beauvericin (100 µM) increases the number of apoptotic germ cells comparable to the positive control UV-C (400 J/m2). Conclusion: Low concentrations of beauvericin are capable to cause adverse effects in C. elegans, which may be relevant for hazard identification of this compound.


Assuntos
Apoptose/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Depsipeptídeos/toxicidade , Células Germinativas/efeitos dos fármacos , Lipofuscina/metabolismo , Longevidade/efeitos dos fármacos , Micotoxinas/toxicidade , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Relação Dose-Resposta a Droga , Fertilidade/efeitos dos fármacos , Contaminação de Alimentos , Células Germinativas/patologia , Atividade Motora/efeitos dos fármacos , Testes de Toxicidade Aguda
2.
Ecotoxicol Environ Saf ; 203: 111001, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888585

RESUMO

Environmental nanomaterials contamination is a great concern for organisms including human. Copper oxide nanoparticles (CuO NPs) are widely used in a huge range of applications which might pose potential risk to organisms. This study investigated the in vivo transgenerational toxicity on development and reproduction with parental CuO NPs exposure in the nematode Caenorhabditis elegans. The results showed that CuO NPs (150 mg/L) significantly reduced the body length of parental C. elegans (P0). Only about 1 mg/L Cu2+ (~0.73%) were detected from 150 mg/L CuO NPs in 0.5X K-medium after 48 h. In transgenerational assays, CuO NPs (150 mg/L) parental exposure significantly induced developmental and reproductive toxicity in non-exposed C. elegans progeny (CuO NPs free) on body length (F1) and brood size (F1 and F2), respectively. In contrast, parental exposure to Cu2+ (1 mg/L) did not cause transgenerational toxicity on growth and reproduction. This suggests that the transgenerational toxicity was mostly attributed to the particulate form of CuO NPs. Moreover, qRT-PCR results showed that the mRNA levels of met-2 and spr-5 genes were significantly decreased at P0 and F1 upon only maternal exposure to CuO NPs (150 mg/L), suggesting the observed transgenerational toxicity was associated with possible epigenetic regulation in C. elegans.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Cobre/toxicidade , Epigênese Genética/efeitos dos fármacos , Nanopartículas/toxicidade , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/fisiologia , Feminino , Humanos , Exposição Materna/efeitos adversos , Reprodução/efeitos dos fármacos , Reprodução/genética
3.
PLoS One ; 15(9): e0238637, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903270

RESUMO

Neonicotinoids, a class of insecticides structurally similar to nicotine that target biting and sucking insects, are the most widely used insecticides today, in part due to their supposed low toxicity in other organisms. However, a growing body of research has found that even low doses of neonicotinoids can induce unexpected negative effects on the physiology and survival of a wide range of non-target organisms. Importantly, no work has been done on the commercial formulations of pesticides that include imidacloprid as the active ingredient, but that also contain many other components. The present study examines the sublethal effects of "Tree and Shrub"™ ("T+S"), a commercial insecticide containing the neonicotinoid imidacloprid as its active ingredient, on Caenorhabditis elegans. We discovered that "T+S" significantly stunted the overall growth in wildtype nematodes, an effect that was exacerbated by concurrent exposure to heat stress. "T+S" also negatively impacted fecundity as measured by increased germline apoptosis, a decrease in egg-laying, and fewer viable offspring. Lastly, exposure to "T+S" resulted in degenerative changes in nicotinic cholinergic neurons in wildtype nematodes. As a whole, these findings demonstrate widespread toxic effects of neonicotinoids to critical functions in nematodes.


Assuntos
Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/fisiologia , Inseticidas/toxicidade , Locomoção/efeitos dos fármacos , Neonicotinoides/toxicidade , Animais , Apoptose/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Neurônios Colinérgicos/efeitos dos fármacos , Neurônios Colinérgicos/metabolismo , Aberrações Cromossômicas , Fertilidade/efeitos dos fármacos , Células Germinativas/citologia , Células Germinativas/efeitos dos fármacos , Resposta ao Choque Térmico , Degeneração Neural/patologia , Oviposição/efeitos dos fármacos , Reprodução/efeitos dos fármacos
4.
Nat Commun ; 11(1): 4639, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934238

RESUMO

The ability to detect, respond and adapt to mitochondrial stress ensures the development and survival of organisms. Caenorhabditis elegans responds to mitochondrial stress by activating the mitochondrial unfolded protein response (UPRmt) to buffer the mitochondrial folding environment, rewire the metabolic state, and promote innate immunity and lifespan extension. Here we show that HDA-1, the C. elegans ortholog of mammalian histone deacetylase (HDAC) is required for mitochondrial stress-mediated activation of UPRmt. HDA-1 interacts and coordinates with the genome organizer DVE-1 to induce the transcription of a broad spectrum of UPRmt, innate immune response and metabolic reprogramming genes. In rhesus monkey and human tissues, HDAC1/2 transcript levels correlate with the expression of UPRmt genes. Knocking down or pharmacological inhibition of HDAC1/2 disrupts the activation of the UPRmt and the mitochondrial network in mammalian cells. Our results underscore an evolutionarily conserved mechanism of HDAC1/2 in modulating mitochondrial homeostasis and regulating longevity.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Histona Desacetilases/metabolismo , Longevidade , Mitocôndrias/enzimologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Histona Desacetilase 1/genética , Histona Desacetilase 2/genética , Histona Desacetilases/genética , Macaca mulatta , Estresse Fisiológico , Resposta a Proteínas não Dobradas
5.
Proc Natl Acad Sci U S A ; 117(33): 19970-19981, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32737159

RESUMO

Mitochondrial fission and fusion are highly regulated by energy demand and physiological conditions to control the production, activity, and movement of these organelles. Mitochondria are arrayed in a periodic pattern in Caenorhabditis elegans muscle, but this pattern is disrupted by mutations in the mitochondrial fission component dynamin DRP-1. Here we show that the dramatically disorganized mitochondria caused by a mitochondrial fission-defective dynamin mutation is strongly suppressed to a more periodic pattern by a second mutation in lysosomal biogenesis or acidification. Vitamin B12 is normally imported from the bacterial diet via lysosomal degradation of B12-binding proteins and transport of vitamin B12 to the mitochondrion and cytoplasm. We show that the lysosomal dysfunction induced by gene inactivations of lysosomal biogenesis or acidification factors causes vitamin B12 deficiency. Growth of the C. elegans dynamin mutant on an Escherichia coli strain with low vitamin B12 also strongly suppressed the mitochondrial fission defect. Of the two C. elegans enzymes that require B12, gene inactivation of methionine synthase suppressed the mitochondrial fission defect of a dynamin mutation. We show that lysosomal dysfunction induced mitochondrial biogenesis, which is mediated by vitamin B12 deficiency and methionine restriction. S-adenosylmethionine, the methyl donor of many methylation reactions, including histones, is synthesized from methionine by S-adenosylmethionine synthase; inactivation of the sams-1 S-adenosylmethionine synthase also suppresses the drp-1 fission defect, suggesting that vitamin B12 regulates mitochondrial biogenesis and then affects mitochondrial fission via chromatin pathways.


Assuntos
Caenorhabditis elegans/metabolismo , Lisossomos/metabolismo , Mitocôndrias/metabolismo , Vitamina B 12/metabolismo , 5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/genética , 5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Dinaminas/genética , Dinaminas/metabolismo , Lisossomos/genética , Mitocôndrias/genética , Dinâmica Mitocondrial , Mutação
6.
Chemosphere ; 261: 127756, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32731027

RESUMO

Urgent need for treatments limit studies of therapeutic drugs before approval by regulatory agencies. Analyses of drugs after approval can therefore improve our understanding of their mechanism of action and enable better therapies. We screened a library of 1443 Food and Drug Administration (FDA)-approved drugs using a simple assay in the nematode C. elegans and found three compounds that caused morphological changes. While the anticoagulant ticlopidine and the antifungal sertaconazole caused both accumulations that resulted in distinct distortions of pharyngeal anatomy and lethality upon acute exposure, the proton-pump inhibitor dexlansoprazole caused molting defects and required exposure during larval development. Such easily detectable defects in a powerful genetic model system advocate the continued exploration of current medicines using a variety of model organisms to better understand drugs already prescribed to millions of patients.


Assuntos
Bioacumulação/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Dexlansoprazol/toxicidade , Imidazóis/toxicidade , Muda/efeitos dos fármacos , Tiofenos/toxicidade , Ticlopidina/toxicidade , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Dexlansoprazol/metabolismo , Aprovação de Drogas , Epigênese Genética/efeitos dos fármacos , Humanos , Imidazóis/metabolismo , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Mutação , Tiofenos/metabolismo , Ticlopidina/metabolismo , Estados Unidos , United States Food and Drug Administration
7.
PLoS Genet ; 16(6): e1008838, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32544191

RESUMO

Reactive oxygen species (ROS) are signalling molecules whose study in intact organisms has been hampered by their potential toxicity. This has prevented a full understanding of their role in organismal processes such as development, aging and disease. In Caenorhabditis elegans, the development of the vulva is regulated by a signalling cascade that includes LET-60ras (homologue of mammalian Ras), MPK-1 (ERK1/2) and LIN-1 (an ETS transcription factor). We show that both mitochondrial and cytoplasmic ROS act on a gain-of-function (gf) mutant of the LET-60ras protein through a redox-sensitive cysteine (C118) previously identified in mammals. We show that the prooxidant paraquat as well as isp-1, nuo-6 and sod-2 mutants, which increase mitochondrial ROS, inhibit the activity of LET-60rasgf on vulval development. In contrast, the antioxidant NAC and loss of sod-1, both of which decrease cytoplasmic H202, enhance the activity of LET-60rasgf. CRISPR replacement of C118 with a non-oxidizable serine (C118S) stimulates LET-60rasgf activity, whereas replacement of C118 with aspartate (C118D), which mimics a strongly oxidised cysteine, inhibits LET-60rasgf. These data strongly suggest that C118 is oxidized by cytoplasmic H202 generated from dismutation of mitochondrial and/or cytoplasmic superoxide, and that this oxidation inhibits LET-60ras. This contrasts with results in cultured mammalian cells where it is mostly nitric oxide, which is not found in worms, that oxidizes C118 and activates Ras. Interestingly, PQ, NAC and the C118S mutation do not act on the phosphorylation of MPK-1, suggesting that oxidation of LET-60ras acts on an as yet uncharacterized MPK-1-independent pathway. We also show that elevated cytoplasmic superoxide promotes vulva formation independently of C118 of LET-60ras and downstream of LIN-1. Finally, we uncover a role for the NADPH oxidases (BLI-3 and DUOX-2) and their redox-sensitive activator CED-10rac in stimulating vulva development. Thus, there are at least three genetically separable pathways by which ROS regulates vulval development.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Peróxidos/metabolismo , Vulva/crescimento & desenvolvimento , Proteínas ras/genética , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Feminino , Mutação com Ganho de Função , Genes de Helmintos/genética , Oxirredução , Oxirredutases/metabolismo , Peróxidos/análise , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo
8.
Cell Prolif ; 53(6): e12832, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32452127

RESUMO

OBJECTIVES: Tumour cell proliferation requires high metabolism to meet the bioenergetics and biosynthetic needs. Dauer in Caenorhabditis elegans is characterized by lower metabolism, and we established an approach with C elegans to find potential tumour therapy targets. MATERIALS AND METHODS: RNAi screening was used to find dauer-related genes, and these genes were further analysed in glp-1(-) mutants for tumour-suppressing testing. The identified tumour-related genes were verified in clinical tumour tissues. RESULTS: The lifespan of glp-1(-) mutants was found to be extended by classical dauer formation signalling. Then, 61 of 287 kinase-coding genes in Caenorhabditis elegans were identified as dauer-related genes, of which 27 were found to be homologous to human oncogenes. Furthermore, 12 dauer-related genes were randomly selected for tumour-suppressing test, and six genes significantly extended the lifespan of glp-1(-) mutants. Of these six genes, F47D12.9, W02B12.12 and gcy-21 were newly linked to dauer formation. These three new dauer-related genes significantly suppressed tumour cell proliferation and thus extended the lifespan of glp-1(-) mutants in a longevity- or dauer-independent manner. The mRNA expression profiles indicated that these dauer-related genes trigged similar low metabolism pattern in glp-1(-) mutants. Notably, the expression of homolog gene DCAF4L2/F47D12.9, TSSK6/W02B12.12 and NPR1/gcy-21 was found to be higher in glioma compared with adjacent normal tissue. In addition, the high expression of TSSK6/W02B12.12 and NPR1/gcy-21 correlated with a worse survival in glioma patients. CONCLUSIONS: Dauer gene screening in combination with tumour-suppressing test in glp-1(-) mutants provided a useful approach to find potential targets for tumour therapy via suppressing tumour cell proliferation and rewiring tumour cell metabolism.


Assuntos
Caenorhabditis elegans/genética , Glioma/metabolismo , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proliferação de Células , Células Germinativas/citologia , Glioma/mortalidade , Glioma/patologia , Humanos , Estimativa de Kaplan-Meier , Longevidade/genética , Mutação , Neoplasias/genética , Prognóstico , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , Receptores do Fator Natriurético Atrial/metabolismo
9.
J Vis Exp ; (158)2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32420986

RESUMO

C. elegans is commonly used to model age-related neurodegenerative diseases caused by repeat expansion mutations, such as Amyotrophic Lateral Sclerosis (ALS) and Huntington's disease. Recently, repeat expansion-containing RNA was shown to be the substrate for a novel type of protein translation called repeat-associated non-AUG-dependent (RAN) translation. Unlike canonical translation, RAN translation does not require a start codon and only occurs when repeats exceed a threshold length. Because there is no start codon to determine the reading frame, RAN translation occurs in all reading frames from both sense and antisense RNA templates that contain a repeat expansion sequence. Therefore, RAN translation expands the number of possible disease-associated toxic peptides from one to six. Thus far, RAN translation has been documented in eight different repeat expansion-based neurodegenerative and neuromuscular diseases. In each case, deciphering which RAN products are toxic, as well as their mechanisms of toxicity, is a critical step towards understanding how these peptides contribute to disease pathophysiology. In this paper, we present strategies to measure the toxicity of RAN peptides in the model system C. elegans. First, we describe procedures for measuring RAN peptide toxicity on the growth and motility of developing C. elegans. Second, we detail an assay for measuring postdevelopmental, age-dependent effects of RAN peptides on motility. Finally, we describe a neurotoxicity assay for evaluating the effects of RAN peptides on neuron morphology. These assays provide a broad assessment of RAN peptide toxicity and may be useful for performing large-scale genetic or small molecule screens to identify disease mechanisms or therapies.


Assuntos
Caenorhabditis elegans/crescimento & desenvolvimento , Expansão das Repetições de DNA , Neurônios/patologia , Iniciação Traducional da Cadeia Peptídica , Fragmentos de Peptídeos/toxicidade , RNA Antissenso/genética , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Neurônios/efeitos dos fármacos
10.
Ecotoxicol Environ Saf ; 197: 110588, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32289633

RESUMO

The ethoxylated isomers of nonylphenol (NPEs, NP-9) are one of the main active ingredients present in nonionic surfactants employed as herbicides, cosmetics, paints, plastics, disinfectants and detergents. These chemicals and their metabolites are commonly found in environmental matrices. The aim of this work was to evaluate the intergenerational toxicity of NP-9 in Caenorhabditis elegans. The lethality, length, width, locomotion and lifespan were investigated in the larval stage L4 of the wild strain N2. Transgenic green fluorescent protein (GFP) strains were employed to estimate changes in relative gene expression. RT-qPCR was utilized to measure mRNA expression for neurotoxicity-related genes (unc-30, unc-25, dop-3, dat-1, mgl-1, and eat-4). Data were obtained from parent worms (P0) and the first generation (F1). Lethality of the nematode was concentration-dependent, with 48 h-LC50 values of 3215 and 1983 µM in P0 and F1, respectively. Non-lethal concentrations of NP-9 reduced locomotion. Lifespan was also decreased by the xenobiotic, but the negative effect was greater in P0 than in F1. Non-monotonic concentration-response curves were observed for body length and width in both generations. The gene expression profile in P0 was different from that registered in F1, although the expression of sod-4, hsp-70, gpx-6 and mtl-2 increased with the surfactant concentration in both generations. None of the tested genes followed a classical concentration-neurotoxicity relationship. In P0, dopamine presented an inverted-U curve, while GABA and glutamate displayed a bimodal type. However, in F1, inverted U-shaped curves were revealed for these genes. In summary, NP-9 induced intergenerational responses in C. elegans through mechanisms involving ROS, and alterations of the GABA, glutamate, and dopamine pathways.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Etilenoglicóis/toxicidade , Tensoativos/toxicidade , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Expressão Gênica/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Dose Letal Mediana , Locomoção/efeitos dos fármacos , Longevidade/efeitos dos fármacos , Neurotransmissores/metabolismo
11.
Parasit Vectors ; 13(1): 162, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32238181

RESUMO

BACKGROUND: While immune responses to the murine hookworm Nippostrongylus brasiliensis have been investigated, signaling pathways regulating development of infectious larvae (iL3) are not well understood. We hypothesized that N. brasiliensis would use pathways similar to those controlling dauer development in the free-living nematode Caenorhabditis elegans, which is formally known as the "dauer hypothesis." METHODS: To investigate whether dafachronic acid activates the N. brasiliensis DAF-12 homolog, we utilized an in vitro reporter assay. We then utilized RNA-Seq and subsequent bioinformatic analyses to identify N. brasiliensis dauer pathway homologs and examine regulation of these genes during iL3 activation. RESULTS: In this study, we demonstrated that dafachronic acid activates the N. brasiliensis DAF-12 homolog. We then identified N. brasiliensis homologs for members in each of the four canonical dauer pathways and examined their regulation during iL3 activation by either temperature or dafachronic acid. Similar to C. elegans, we found that transcripts encoding antagonistic insulin-like peptides were significantly downregulated during iL3 activation, and that a transcript encoding a phylogenetic homolog of DAF-9 increased during iL3 activation, suggesting that both increased insulin-like and DAF-12 nuclear hormone receptor signaling accompanies iL3 activation. In contrast to C. elegans, we observed a significant decrease in transcripts encoding the dauer transforming growth factor beta ligand DAF-7 during iL3 activation, suggesting a different role for this pathway in parasitic nematode development. CONCLUSIONS: Our data suggest that canonical dauer pathways indeed regulate iL3 activation in the hookworm N. brasiliensis and that DAF-12 may be a therapeutic target in hookworm infections.


Assuntos
Colestenos/farmacologia , Nippostrongylus/efeitos dos fármacos , Nippostrongylus/genética , Transdução de Sinais/efeitos dos fármacos , Temperatura , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Biologia Computacional , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Helminto/genética , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Filogenia , RNA-Seq
12.
Adv Parasitol ; 108: 175-229, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32291085

RESUMO

In the past two decades, significant progress has been made in the sequencing, assembly, annotation and analyses of genomes and transcriptomes of parasitic worms of socioeconomic importance. This progress has somewhat improved our knowledge and understanding of these pathogens at the molecular level. However, compared with the free-living nematode Caenorhabditis elegans, the areas of functional genomics, transcriptomics, proteomics and metabolomics of parasitic nematodes are still in their infancy, and there are major gaps in our knowledge and understanding of the molecular biology of parasitic nematodes. The information on signalling molecules, molecular pathways and microRNAs (miRNAs) that are known to be involved in developmental processes in C. elegans and the availability of some molecular resources (draft genomes, transcriptomes and some proteomes) for selected parasitic nematodes provide a basis to start exploring the developmental biology of parasitic nematodes. Indeed, some studies have identified molecules and pathways that might associate with developmental processes in related, parasitic nematodes, such as Haemonchus contortus (barber's pole worm). However, detailed information is often scant and 'omics resources are limited, preventing a proper integration of 'omic data sets and comprehensive analyses. Moreover, little is known about the functional roles of pheromones, hormones, signalling pathways and post-transcriptional/post-translational regulations in the development of key parasitic nematodes throughout their entire life cycles. Although C. elegans is an excellent model to assist molecular studies of parasitic nematodes, its use is limited when it comes to explorations of processes that are specific to parasitism within host animals. A deep understanding of parasitic nematodes, such as H. contortus, requires substantially enhanced resources and the use of integrative 'omics approaches for analyses. The improved genome and well-established in vitro larval culture system for H. contortus provide unprecedented opportunities for comprehensive studies of the transcriptomes (mRNA and miRNA), proteomes (somatic, excretory/secretory and phosphorylated proteins) and lipidomes (e.g., polar and neutral lipids) of this nematode. Such resources should enable in-depth explorations of its developmental biology at a level, not previously possible. The main aims of this review are (i) to provide a background on the development of nematodes, with a particular emphasis on the molecular aspects involved in the dauer formation and exit in C. elegans; (ii) to critically appraise the current state of knowledge of the developmental biology of parasitic nematodes and identify key knowledge gaps; (iii) to cover salient aspects of H. contortus, with a focus on the recent advances in genomics, transcriptomics, proteomics and lipidomics as well as in vitro culturing systems; (iv) to review recent advances in our knowledge and understanding of the molecular and developmental biology of H. contortus using an integrative multiomics approach, and discuss the implications of this approach for detailed explorations of signalling molecules, molecular processes and pathways likely associated with nematode development, adaptation and parasitism, and for the identification of novel intervention targets against these pathogens. Clearly, the multiomics approach established recently is readily applicable to exploring a wide range of interesting and socioeconomically significant parasitic worms (including also trematodes and cestodes) at the molecular level, and to elucidate host-parasite interactions and disease processes.


Assuntos
Biologia Computacional , Nematoides/crescimento & desenvolvimento , Nematoides/genética , Infecções por Nematoides/parasitologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Interações Hospedeiro-Parasita/fisiologia , Humanos , Parasitos/genética , Parasitos/crescimento & desenvolvimento
13.
Mol Cell ; 78(4): 700-713.e7, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32289254

RESUMO

Impairment of ribosome function activates the MAPKKK ZAK, leading to activation of mitogen-activated protein (MAP) kinases p38 and JNK and inflammatory signaling. The mechanistic basis for activation of this ribotoxic stress response (RSR) remains completely obscure. We show that the long isoform of ZAK (ZAKα) directly associates with ribosomes by inserting its flexible C terminus into the ribosomal intersubunit space. Here, ZAKα binds helix 14 of 18S ribosomal RNA (rRNA). An adjacent domain in ZAKα also probes the ribosome, and together, these sensor domains are critically required for RSR activation after inhibition of both the E-site, the peptidyl transferase center (PTC), and ribotoxin action. Finally, we show that ablation of the RSR response leads to organismal phenotypes and decreased lifespan in the nematode Caenorhabditis elegans (C. elegans). Our findings yield mechanistic insight into how cells detect ribotoxic stress and provide experimental in vivo evidence for its physiological importance.


Assuntos
Caenorhabditis elegans/crescimento & desenvolvimento , MAP Quinase Quinase Quinases/metabolismo , Peptidil Transferases/metabolismo , RNA Ribossômico 18S/metabolismo , Ribossomos/metabolismo , Estresse Fisiológico , Sequência de Aminoácidos , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Ativação Enzimática , Células HeLa , Humanos , MAP Quinase Quinase Quinases/antagonistas & inibidores , MAP Quinase Quinase Quinases/genética , Conformação Proteica , Domínios Proteicos , RNA Ribossômico 18S/genética , Homologia de Sequência , Transdução de Sinais
14.
Genes Cells ; 25(6): 391-401, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32167217

RESUMO

Vesicular transport serves as an important mechanism for cell shape regulation during development. Although the semaphorin signaling molecule, a well-known regulator of axon guidance, induces endocytosis in the growth cone and the axonal transport of vertebrate neurons, the underlying molecular mechanisms remain largely unclear. Here, we show that the Caenorhabditis elegans SNT-1/synaptotagmin-UNC-41/stonin2 system, whose role in synaptic vesicle recycling in neurons has been studied extensively, is involved in semaphorin-regulated vesicular transport in larval epidermal cells. Mutations in the snt-1/unc-41 genes strongly suppressed the cell shape defects of semaphorin mutants. The null mutation in the semaphorin receptor gene, plx-1, altered the expression and localization pattern of endocytic and exocytic markers in the epidermal cells while repressing the transport of SNT-1-containing vesicles toward late endosome/lysosome pathways. Our findings suggest that the nematode semaphorins regulate the vesicular transport in epidermal cells in a manner distinct from that of vertebrate semaphorins in neurons.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Células Epidérmicas/metabolismo , Semaforinas/metabolismo , Vesículas Sinápticas/metabolismo , Sinaptotagminas/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Animais Geneticamente Modificados , Transporte Biológico Ativo/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Endocitose/genética , Endossomos/genética , Endossomos/metabolismo , Exocitose/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Lisossomos/genética , Lisossomos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Interferência de RNA , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Semaforinas/genética , Transdução de Sinais/genética , Sinaptotagminas/genética , Proteínas de Transporte Vesicular/genética
15.
BMC Biol ; 18(1): 31, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188449

RESUMO

BACKGROUND: Metabolic activity alternates between high and low states during different stages of an organism's life cycle. During the transition from growth to quiescence, a major metabolic shift often occurs from oxidative phosphorylation to glycolysis and gluconeogenesis. We use the entry of Caenorhabditis elegans into the dauer larval stage, a developmentally arrested stage formed in response to harsh environmental conditions, as a model to study the global metabolic changes and underlying molecular mechanisms associated with growth to quiescence transition. RESULTS: Here, we show that the metabolic switch involves the concerted activity of several regulatory pathways. Whereas the steroid hormone receptor DAF-12 controls dauer morphogenesis, the insulin pathway maintains low energy expenditure through DAF-16/FoxO, which also requires AAK-2/AMPKα. DAF-12 and AAK-2 separately promote a shift in the molar ratios between competing enzymes at two key branch points within the central carbon metabolic pathway diverting carbon atoms from the TCA cycle and directing them to gluconeogenesis. When both AAK-2 and DAF-12 are suppressed, the TCA cycle is active and the developmental arrest is bypassed. CONCLUSIONS: The metabolic status of each developmental stage is defined by stoichiometric ratios within the constellation of metabolic enzymes driving metabolic flux and controls the transition between growth and quiescence.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Diapausa/genética , Regulação da Expressão Gênica no Desenvolvimento , Transdução de Sinais/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo
16.
Development ; 147(5)2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32041790

RESUMO

In many eukaryotes, the small GTPase Rheb functions as a switch to toggle activity of TOR complex 1 (TORC1) between anabolism and catabolism, thus controlling lifespan, development and autophagy. Our CRISPR-generated, fluorescently tagged endogenous Caenorhabditis elegans RHEB-1 and DAF-15/Raptor are expressed ubiquitously and localize to lysosomes. LET-363/TOR and DAF-15/Raptor are required for development beyond the third larval stage (L3). We observed that deletion of RHEB-1 similarly conferred L3 arrest. Unexpectedly, robust RNAi-mediated depletion of TORC1 components caused arrest at stages prior to L3. Accordingly, conditional depletion of endogenous DAF-15/Raptor in the soma revealed that TORC1 is required at each stage of the life cycle to progress to the next stage. Reversal of DAF-15 depletion permits arrested animals to recover to continue development. Our results are consistent with TORC1 functioning as a developmental checkpoint that governs the decision of the animal to progress through development.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/crescimento & desenvolvimento , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Animais , Animais Geneticamente Modificados , Autofagia/fisiologia , Sistemas CRISPR-Cas/genética , Caenorhabditis elegans/genética , Estágios do Ciclo de Vida/genética , Longevidade/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo/genética , Transdução de Sinais
17.
Sci Rep ; 10(1): 103, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919410

RESUMO

Fanconi Anemia is a rare genetic disease associated with DNA repair defects, congenital abnormalities and infertility. Most of FA pathway is evolutionary conserved, allowing dissection and mechanistic studies in simpler model systems such as Caenorhabditis elegans. In the present study, we employed C. elegans to better understand the role of FA group D2 (FANCD2) protein in vivo, a key player in promoting genome stability. We report that localization of FCD-2/FANCD2 is dynamic during meiotic prophase I and requires its heterodimeric partner FNCI-1/FANCI. Strikingly, we found that FCD-2 recruitment depends on SPO-11-induced double-strand breaks (DSBs) but not RAD-51-mediated strand invasion. Furthermore, exposure to DNA damage-inducing agents boosts FCD-2 recruitment on the chromatin. Finally, analysis of genetic interaction between FCD-2 and BRC-1 (the C. elegans orthologue of mammalian BRCA1) supports a role for these proteins in different DSB repair pathways. Collectively, we showed a direct involvement of FCD-2 at DSBs and speculate on its function in driving meiotic DNA repair.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Meiose , Recombinação Genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética
18.
Dev Cell ; 52(1): 88-103.e18, 2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31910362

RESUMO

After axon outgrowth and synapse formation, the nervous system transitions to a stable architecture. In C. elegans, this transition is marked by the appearance of casein kinase 1δ (CK1δ) in the nucleus. In CK1δ mutants, neurons continue to sprout growth cones into adulthood, leading to a highly ramified nervous system. Nervous system architecture in these mutants is completely restored by suppressor mutations in ten genes involved in transcription termination. CK1δ prevents termination by phosphorylating and inhibiting SSUP-72. SSUP-72 would normally remodel the C-terminal domain of RNA polymerase in anticipation of termination. The antitermination activity of CK1δ establishes the mature state of a neuron by promoting the expression of the long isoform of a single gene, the cytoskeleton protein Ankyrin.


Assuntos
Anquirinas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Caseína Quinase Idelta/metabolismo , Núcleo Celular/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Transcrição Genética , Animais , Anquirinas/genética , Axônios/fisiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Caseína Quinase Idelta/genética , Núcleo Celular/genética , Fosfoproteínas Fosfatases/genética , Sinapses/fisiologia
19.
Proc Natl Acad Sci U S A ; 117(2): 1015-1020, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31892536

RESUMO

To function effectively proteins must avoid aberrant aggregation, and hence they are expected to be expressed at concentrations safely below their solubility limits. By analyzing proteome-wide mass spectrometry data of Caenorhabditis elegans, however, we show that the levels of about three-quarters of the nearly 4,000 proteins analyzed in adult animals are close to their intrinsic solubility limits, indeed exceeding them by about 10% on average. We next asked how aging and functional self-assembly influence these solubility limits. We found that despite the fact that the total quantity of proteins within the cellular environment remains approximately constant during aging, protein aggregation sharply increases between days 6 and 12 of adulthood, after the worms have reproduced, as individual proteins lose their stoichiometric balances and the cellular machinery that maintains solubility undergoes functional decline. These findings reveal that these proteins are highly prone to undergoing concentration-dependent phase separation, which on aging is rationalized in a decrease of their effective solubilities, in particular for proteins associated with translation, growth, reproduction, and the chaperone system.


Assuntos
Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteoma/química , Proteoma/metabolismo , Envelhecimento/fisiologia , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Homeostase , Espectrometria de Massas , Chaperonas Moleculares/metabolismo , Agregados Proteicos/fisiologia , Dobramento de Proteína , Solubilidade
20.
Int J Mol Sci ; 21(1)2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31948007

RESUMO

Nobiletin (NOB), one of polymethoxyflavone existing in citrus fruits, has been reported to exhibit a multitude of biological properties, including anti-inflammation, anti-oxidation, anti-atherosclerosis, neuroprotection, and anti-tumor activity. However, little is known about the anti-aging effect of NOB. The objective of this study was to determine the effects of NOB on lifespan, stress resistance, and its associated gene expression. Using Caenorhabditis elegans, an in vivo nematode model, we found that NOB remarkably extended the lifespan; slowed aging-related functional declines; and increased the resistance against various stressors, including heat shock and ultraviolet radiation. Also, NOB reduced the effects of paraquat stressor on nematodes and scavenged reactive oxygen species (ROS). Furthermore, gene expression revealed that NOB upregulated the expression of sod-3, hsp-16.2, gst-4, skn-1, sek-1, and sir-2.1, which was suggested that anti-aging activity of NOB was mediated most likely by activation of the target genes of the transcription factors including dauer formation (DAF)-16, heat-shock transcription factor (HSF)-1, and skinhead (SKN)-1. In summary, NOB has potential application in extension of lifespan, and its associated healthspan and stress resistances.


Assuntos
Caenorhabditis elegans/metabolismo , Flavonas/farmacologia , Longevidade/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Citrus/química , Citrus/metabolismo , Flavonas/química , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Lipofuscina/metabolismo , Longevidade/efeitos da radiação , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Reprodução/efeitos dos fármacos , Temperatura , Raios Ultravioleta
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