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1.
Nucleic Acids Res ; 48(4): 1811-1827, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31872227

RESUMO

Piwi-interacting RNAs (piRNAs) and small interfering RNAs (siRNAs) are distinct classes of small RNAs required for proper germline development. To identify the roles of piRNAs and siRNAs in regulating gene expression in Caenorhabditis elegans, we subjected small RNAs and mRNAs from the gonads of piRNA and siRNA defective mutants to high-throughput sequencing. We show that piRNAs and an abundant class of siRNAs known as WAGO-class 22G-RNAs are required for proper expression of spermatogenic and oogenic genes. WAGO-class 22G-RNAs are also broadly required for transposon silencing, whereas piRNAs are largely dispensable. piRNAs, however, have a critical role in controlling histone gene expression. In the absence of piRNAs, histone mRNAs are misrouted into the nuclear RNAi pathway involving the Argonaute HRDE-1, concurrent with a reduction in the expression of many histone mRNAs. We also show that high-level gene expression in the germline is correlated with high level 22G-RNA production. However, most highly expressed genes produce 22G-RNAs through a distinct pathway that presumably involves the Argonaute CSR-1. In contrast, genes targeted by the WAGO branch of the 22G-RNA pathway are typically poorly expressed and respond unpredictably to loss of 22G-RNAs. Our results point to broad roles for piRNAs and siRNAs in controlling gene expression in the C. elegans germline.


Assuntos
Proteínas Argonauta/genética , Proteínas de Caenorhabditis elegans/genética , RNA Interferente Pequeno/genética , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento/genética , Inativação Gênica , Células Germinativas/crescimento & desenvolvimento , Sequenciamento de Nucleotídeos em Larga Escala , Histonas/genética , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA Mensageiro/genética , Transcriptoma/genética
2.
Ecotoxicol Environ Saf ; 187: 109709, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31654870

RESUMO

Among the most used chemicals in the world are nonionic surfactants. One of these environmental pollutants is nonylphenol ethoxylate (NP-9), also known as Tergitol, and its degradation product, nonylphenol (NP). The objective of this work was to determine the toxicity of NP and NP-9 in Caenorhabditis elegans. Wild-type L4 larvae were exposed to different concentrations of the surfactants to measure functional endpoints. Mutant strains were employed to promote the activation of toxicity signaling pathways related to mtl-2, gst-1, gpx-4, gpx-6, sod-4, hsp-70 and hsp-4. Additionally, stress response was also assessed using a daf-16::GFP transgenic strain. The lethality was concentration dependent, with 24-h LC50 of 122 µM and 3215 µM for NP and NP-9, respectively. Both compounds inhibited nematode growth, although NP was more potent; and at non-lethal concentrations, nematode locomotion was reduced. The increase in the expression of tested genes was significant at 10 µM for NP-9 and 0.001 µM for NP, implying a likely role for the activation of oxidative and cellular stress, as well as metabolism pathways. With the exception of glutathione peroxidase, which has a bimodal concentration-response curve for NP, typical of endocrine disruption, the other curves for this xenobiotic in the strains evaluated were almost flat for most concentrations, until reaching 50-100 µM, where the effect peaked. NP and NP-9 induced the activation and nuclear translocation of DAF-16, suggesting that transcription of stress-response genes may be mediated by the insulin/IGF-1 signaling pathway. In contrast, NP-9 induced a concentration-dependent response for the sod-4 and hsp-4 mutants, with greater fluorescence induction than NP at similar levels. In short, NP and NP-9 affect the physiology of C. elegans and modulate gene expression related to ROS production, cellular stress and metabolism of xenobiotics.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Poluentes Ambientais/toxicidade , Etilenoglicóis/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Fenóis/toxicidade , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Expressão Gênica/efeitos dos fármacos , Larva/metabolismo , Dose Letal Mediana , Locomoção/efeitos dos fármacos , Estresse Oxidativo/genética
3.
BMC Complement Altern Med ; 19(1): 313, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730453

RESUMO

BACKGROUND: Jianpi-yangwei (JPYW), a traditional Chinese medicine (TCM), helps to nourish the stomach and spleen and is primarily used to treat functional declines related to aging. This study aimed to explore the antiaging effects and mechanism of JPYW by employing a Caenorhabditis elegans model. METHODS: Wild-type C. elegans N2 worms were cultured in growth medium with or without JPYW, and lifespan analysis, oxidative and heat stress resistance assays, and other aging-related assays were performed. The effects of JPYW on the levels of superoxide dismutase (SOD) and the expression of specific genes were examined to explore the underlying mechanism of JPYW. RESULTS: Compared to control worms, JPYW-treated wild-type worms showed increased survival times under both normal and stress conditions (P < 0.05). JPYW-treated worms also exhibited enhanced reproduction, movement and growth and decreased intestinal lipofuscin accumulation compared to controls (P < 0.05). Furthermore, increased activity of SOD, downregulated expression levels of the proaging gene clk-2 and upregulated expression levels of the antiaging genes daf-16, skn-1, and sir-2.1 were observed in the JPYW group compared to the control group. CONCLUSION: Our findings suggest that JPYW extends the lifespan of C. elegans and exerts antiaging effects by increasing the activity of an antioxidant enzyme (SOD) and by regulating the expression of aging-related genes. This study not only indicates that this Chinese compound exerts antiaging effects by activating and repressing target genes but also provides a proven methodology for studying the biological mechanisms of TCMs.


Assuntos
Envelhecimento/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Envelhecimento/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Humanos , Longevidade/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
4.
PLoS Biol ; 17(10): e3000452, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31589601

RESUMO

Neurons have a lifespan that parallels that of the organism and are largely irreplaceable. Their unusually long lifespan predisposes neurons to neurodegenerative disease. We sought to identify physiological mechanisms that delay neuron aging in Caenorhabditis elegans by asking how neuron morphological aging is arrested in the long-lived, alternate organismal state, the dauer diapause. We find that a hormone signaling pathway, the abnormal DAuer Formation (DAF) 12 nuclear hormone receptor (NHR) pathway, functions cell-intrinsically in the dauer diapause to arrest neuron morphological aging, and that same pathway can be cell-autonomously manipulated during normal organismal aging to delay neuron morphological aging. This delayed aging is mediated by suppressing constitutive endocytosis, which alters the subcellular localization of the actin regulator T cell lymphoma Invasion And Metastasis 1 (TIAM-1), thereby decreasing age-dependent neurite growth. Intriguingly, we show that suppressed endocytosis appears to be a general feature of cells in diapause, suggestive that this may be a mechanism to halt the growth and other age-related programs supported by most endosome recycling.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Diapausa/genética , Longevidade/genética , Neurônios/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Proteína 1 Indutora de Invasão e Metástase de Linfoma de Células T/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Senescência Celular/genética , Endocitose/genética , Endossomos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Neurônios/citologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais , Proteína 1 Indutora de Invasão e Metástase de Linfoma de Células T/metabolismo
5.
PLoS Genet ; 15(10): e1008067, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31584932

RESUMO

microRNAs (miRNAs) are potent regulators of gene expression that function in diverse developmental and physiological processes. Argonaute proteins loaded with miRNAs form the miRNA Induced Silencing Complexes (miRISCs) that repress gene expression at the post-transcriptional level. miRISCs target genes through partial sequence complementarity between the miRNA and the target mRNA's 3' UTR. In addition to being targeted by miRNAs, these mRNAs are also extensively regulated by RNA-binding proteins (RBPs) through RNA processing, transport, stability, and translation regulation. While the degree to which RBPs and miRISCs interact to regulate gene expression is likely extensive, we have only begun to unravel the mechanisms of this functional cooperation. An RNAi-based screen of putative ALG-1 Argonaute interactors has identified a role for a conserved RNA binding protein, HRPK-1, in modulating miRNA activity during C. elegans development. Here, we report the physical and genetic interaction between HRPK-1 and ALG-1/miRNAs. Specifically, we report the genetic and molecular characterizations of hrpk-1 and its role in C. elegans development and miRNA-mediated target repression. We show that loss of hrpk-1 causes numerous developmental defects and enhances the mutant phenotypes associated with reduction of miRNA activity, including those of lsy-6, mir-35-family, and let-7-family miRNAs. In addition to hrpk-1 genetic interaction with these miRNA families, hrpk-1 is required for efficient regulation of lsy-6 target cog-1. We report that hrpk-1 plays a role in processing of some but not all miRNAs and is not required for ALG-1/AIN-1 miRISC assembly. We suggest that HRPK-1 may functionally interact with miRNAs by both affecting miRNA processing and by enhancing miRNA/miRISC gene regulatory activity and present models for its activity.


Assuntos
Proteínas Argonauta/genética , Caenorhabditis elegans/genética , Desenvolvimento Embrionário/genética , Complexo de Inativação Induzido por RNA/genética , Regiões 3' não Traduzidas/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Proteínas de Transporte/genética , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Homeodomínio/genética , MicroRNAs/genética , Domínios Proteicos/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética
6.
Nat Commun ; 10(1): 4905, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659167

RESUMO

Therapeutic activation of mitochondrial function has been suggested as an effective strategy to combat aging. Hydralazine is an FDA-approved drug used in the treatment of hypertension, heart failure and cancer. Hydralazine has been recently shown to promote lifespan in C. elegans, rotifer and yeast through a mechanism which has remained elusive. Here we report cAMP-dependent protein kinase (PKA) as the direct target of hydralazine. Using in vitro and in vivo models, we demonstrate a mechanism in which binding and stabilization of a catalytic subunit of PKA by hydralazine lead to improved mitochondrial function and metabolic homeostasis via the SIRT1/SIRT5 axis, which underlies hydralazine's prolongevity and stress resistance benefits. Hydralazine also protects mitochondrial metabolism and function resulting in restoration of health and lifespan in C. elegans under high glucose and other stress conditions. Our data also provide new insights into the mechanism(s) that explain various other known beneficial effects of hydralazine.


Assuntos
Envelhecimento/efeitos dos fármacos , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Hidralazina/administração & dosagem , Sirtuína 1/metabolismo , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/genética , Feminino , Humanos , Longevidade/efeitos dos fármacos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Sirtuína 1/genética
7.
Environ Pollut ; 254(Pt B): 113078, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31479814

RESUMO

Our previous study showed heritable reproductive toxicity in the nematode Caenorhabditis elegans after multigenerational exposure to AgNO3 and silver nanoparticles (Ag-NPs). The aim of this study was to determine whether such inheritable effects are correlated with induced germline mutations in C. elegans. Individual C. elegans lineages were exposed for 10 generations to equitoxic concentrations at EC30 of AgNO3, Ag-NPs, and sulfidized Ag-NPs (sAg-NPs), a predominant environmentally transformed product of pristine Ag-NPs. The mutations were detected via whole genome DNA sequencing approach by comparing F0 and F10 generations. An increase in the total number of variants, though not statistically significant, was observed for all Ag treatments and the variants were mainly contributed by single nucleotide polymorphisms (SNPs). This potentially contributed towards reproductive as well as growth toxicity shown previously after ten generations of exposure in every Ag treatment. However, despite Ag-NPs and AgNO3 inducing stronger reproductive toxicity than sAg-NPs, exposure to sAg-NPs resulted in higher mutation accumulation with significant increase in the number of transversions. Thus our results suggest that other mechanisms of inheritance, such as epigenetics, may be at play in Ag-NP- and AgNO3-induced multigenerational and transgenerational reproductive toxicity.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/fisiologia , Feminino , Genômica , Masculino , Nanopartículas Metálicas/química , Mutação/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Prata/química
8.
Genetics ; 213(2): 615-632, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31395653

RESUMO

The diversity in sperm shape and size represents a powerful paradigm to understand how selection drives the evolutionary diversification of cell morphology. Experimental work on the sperm biology of the male-hermaphrodite nematode Caenorhabditis elegans has elucidated diverse factors important for sperm fertilization success, including the competitive superiority of larger sperm. Yet despite extensive research, the molecular mechanisms regulating C . elegans sperm size and the genetic basis underlying natural variation in sperm size remain unknown. To address these questions, we quantified male sperm size variation of a worldwide panel of 97 genetically distinct C. elegans strains, allowing us to uncover significant genetic variation in male sperm size. Aiming to characterize the molecular genetic basis of C. elegans male sperm size variation using a genome-wide association study, we did not detect any significant quantitative trait loci. We therefore focused on the genetic analysis of pronounced sperm size differences observed between recently diverged laboratory strains (N2 vs. LSJ1/2). Using mutants and quantitative complementation tests, we demonstrate that variation in the gene nurf-1 underlies the evolution of small sperm in the LSJ lineage. Given the previous discovery that this same nurf-1 variation was central for hermaphrodite laboratory adaptation, the evolution of reduced male sperm size in LSJ strains likely reflects a pleiotropic consequence. Together, our results provide a comprehensive quantification of natural variation in C. elegans sperm size and first insights into the genetic determinants of Caenorhabditis sperm size, pointing at an involvement of the NURF chromatin remodeling complex.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Tamanho Celular , Proteínas Cromossômicas não Histona/genética , Espermatozoides/citologia , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Linhagem da Célula/genética , Montagem e Desmontagem da Cromatina , Transtornos do Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/patologia , Fertilização/genética , Variação Genética/genética , Estudo de Associação Genômica Ampla , Masculino , Locos de Características Quantitativas/genética , Espermatozoides/crescimento & desenvolvimento
9.
Chem Biol Interact ; 311: 108774, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31369748

RESUMO

Silica nanoparticles (SiNPs) are one of the popular nanomaterials used in industrial manufacturing, synthesis, engineering, and medicine. Recently, mechanisms underlying toxicity of silica nanoparticles have been reported; however, their uptake mechanisms have still not fully understood. In this study, toxicity of SiNPs was investigated in the nematode Caenohabditis elegans by using microarray and pathway analysis focusing the uptake mechanisms and their impact on toxicity. Physicochemical characterization of SiNPs was performed using dynamic light scattering (DLS) and zeta potential. No mortality was observed after 24 h exposure to SiNPs. However, reproductive ability was significantly reduced at the same concentrations. To ascertain a global mechanism of toxicity, microarray was conducted on C. elegans exposed to 10 mg/L SiNPs (20% reduction in reproductive ability). Microarray results indicated that genes involved in reproduction, such as msp (Major Sperm Protein) genes, were significantly downregulated in C. elegans exposed to SiNPs. Pathway analyses on differentially expressed genes (DEGs) revealed that endocytic pathway as a major pathway involved in the uptake of SiNPs. Involvement of endocytic pathway in the uptake of SiNPs was assessed using specific inhibitors (methyl-ß-cyclodextrin, chlorpromazine, and LY294002 for caveolin-, clathrin-, and pinocytosis-mediated endocytosis, respectively). The inhibitor assay indicated that an internalization process facilitated by clathrin-mediated endocytosis is involved in the uptake of SiNPs. Functional analysis using endocytosis defective mutants, (i,e.  cav-1, cup-2, and chc-1) confirmed the role of endocytosis on the reproductive toxicity of SiNPs. Overall results suggest that clathrin-mediated endocytosis pathway is a potential mechanism of uptake of SiNPs in C. elegans that in turn, affects general toxic outcome, such as, decrease in reproductive ability.


Assuntos
Caenorhabditis elegans/metabolismo , Clatrina/metabolismo , Endocitose/efeitos dos fármacos , Nanopartículas/toxicidade , Dióxido de Silício/química , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Redes Reguladoras de Genes/efeitos dos fármacos , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Reprodução/efeitos dos fármacos , beta-Ciclodextrinas/química , beta-Ciclodextrinas/farmacologia
10.
Genetics ; 213(2): 491-500, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31371405

RESUMO

Axon regeneration following neuronal injury is an important repair mechanism that is not well understood at present. In Caenorhabditis elegans, axon regeneration is regulated by DDR-2, a receptor tyrosine kinase (RTK) that contains a discoidin domain and modulates the Met-like SVH-2 RTK-JNK MAP kinase signaling pathway. Here, we describe the svh-10/sqv-3 and svh-11 genes, which encode components of a conserved glycosylation pathway, and show that they modulate axon regeneration in C . elegans Overexpression of svh-2, but not of ddr-2, can suppress the axon regeneration defect observed in svh-11 mutants, suggesting that SVH-11 functions between DDR-2 and SVH-2 in this glycosylation pathway. Furthermore, we found that DDR-2 is N-glycosylated at the Asn-141 residue located in its discoidin domain, and mutation of this residue caused an axon regeneration defect. These findings indicate that N-linked glycosylation plays an important role in axon regeneration in C. elegans.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Receptor com Domínio Discoidina 2/genética , Regeneração Nervosa/genética , Receptores Proteína Tirosina Quinases/genética , Animais , Axônios/metabolismo , Axônios/fisiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Receptores com Domínio Discoidina/genética , Glicosilação , Sistema de Sinalização das MAP Quinases/genética , Mutação , Neurônios/metabolismo
11.
Elife ; 82019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31386623

RESUMO

Cellular differentiation requires both activation of target cell transcriptional programs and repression of non-target cell programs. The Myt1 family of zinc finger transcription factors contributes to fibroblast to neuron reprogramming in vitro. Here, we show that ztf-11 (Zinc-finger Transcription Factor-11), the sole Caenorhabditis elegans Myt1 homolog, is required for neurogenesis in multiple neuronal lineages from previously differentiated epithelial cells, including a neuron generated by a developmental epithelial-to-neuronal transdifferentiation event. ztf-11 is exclusively expressed in all neuronal precursors with remarkable specificity at single-cell resolution. Loss of ztf-11 leads to upregulation of non-neuronal genes and reduced neurogenesis. Ectopic expression of ztf-11 in epidermal lineages is sufficient to produce additional neurons. ZTF-11 functions together with the MuvB corepressor complex to suppress the activation of non-neuronal genes in neurons. These results dovetail with the ability of Myt1l (Myt1-like) to drive neuronal transdifferentiation in vitro in vertebrate systems. Together, we identified an evolutionarily conserved mechanism to specify neuronal cell fate by repressing non-neuronal genes.


Assuntos
Caenorhabditis elegans/crescimento & desenvolvimento , Diferenciação Celular , Células Epiteliais/fisiologia , Regulação da Expressão Gênica , Neurônios/fisiologia , Animais
12.
Food Funct ; 10(9): 5531-5543, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31418439

RESUMO

Caenorhabditis elegans is an important model organism for studying stress response mechanisms and identifying genetic pathways that influence longevity. The present study was designed to explore the in vivo-antioxidant potential and the probable mechanism of acid hydrolysates prepared from A. auricula polysaccharides (AAPHs-F) with the optimal acid hydrolysis conditions using Box-Behnken design, and C. elegans was used as a model organism. The effects of AAPHs-F on the locomotory behavior, lifespan, activities of antioxidant-related enzymes and levels of antioxidants in C. elegans were studied. In addition, the potential of AAPHs-F in up-regulating the expression of antioxidant-related genes in C. elegans, such as daf-16, skn-1, sod-1, sod-2 and sir-2.1, and the inhibition of cell apoptosis of C. elegans were also discussed. The results indicated that AAPHs-F could significantly increase the U-Turn frequency of nematodes, extend their lifespan, enhance antioxidant systems including superoxide dismutase (SOD) by 70.60%, catalase (CAT) by 73.45% and glutathione reductase (GR) by 258.68% (p < 0.01), increase the level of glutathione (GSH) by 110.22% (p < 0.01), and decrease the level of reactive oxygen species (ROS) and malondialdehyde (MDA) by 31.86% and 46.16% (p < 0.01), respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) results showed that AAPHs-F could up-regulate mRNA expression levels of daf-16, skn-1, sir, sod-1 and sod-2 in wild-type C. elegans (>1.3 fold) when treated at a concentration of 0.1 mg mL-1 (p < 0.05 or p < 0.01). AAPHs-F was concluded to be heteropolysaccharides composed of mannose, glucose and galactose with a molar ratio of 12.7 : 3.25 : 1. The molecular weight of AAPHs-F was determined to be 885.37 Da. Furthermore, AAPHs-F is mainly formed of (1 → 3)-linked-α-d-glucopyranose, and carboxyl or acetamide is present in the molecule. In summary, our studies provide evidence that AAPHs-F helps improve the antioxidant defense system, and up-regulation of stress and longevity related genes suggests the possible involvement of these genes in the prevention of stress damage in C. elegans.


Assuntos
Antioxidantes/farmacologia , Basidiomycota/química , Caenorhabditis elegans/efeitos dos fármacos , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Animais , Antioxidantes/química , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Catalase/genética , Catalase/metabolismo , Glutationa/metabolismo , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Hidrólise , Longevidade/efeitos dos fármacos , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Polissacarídeos/química , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
13.
BMC Complement Altern Med ; 19(1): 209, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409340

RESUMO

BACKGROUND: The imbalance between the generation of free radicals and natural cellular antioxidant defenses, known as oxidative stress, can cause oxidation of biomolecules and further contribute to aging-associated diseases. The purpose of this study was to evaluate the antioxidant capacities of Thai traditional tonifying preparation, Jatu-Phala-Tiga (JPT) and its herbal ingredients consisting of Phyllanthus emblica, Terminalia arjuna, Terminalia chebula, and Terminalia bellirica and further assess its effect on longevity. METHOD: Antioxidant activities of various extracts obtained from JPT and its herbal components were carried out using well-established methods including metal chelating, free radical scavenging, and ferric reducing antioxidant power assays. Qualitative analysis of the chemical composition from JPT water extract was done by high-performance liquid chromatography tandem with electrospray ionisation mass spectrometry. The effect of JPT water extract on the lifespan of Caenorhabditis elegans were additionally described. RESULTS: Among the extracts, JPT water extract exerted remarkable antioxidant activities as compared to the extracts from other solvents and individual constituting plant extract. JPT water extract was found to possess the highest metal chelating activity, with an IC50 value of 1.75 ± 0.05 mg/mL. Moreover, it exhibited remarkable scavenging activities towards DPPH, ABTS, and superoxide anion radicals, with IC50 values of 0.31 ± 0.02, 0.308 ± 0.004, and 0.055 ± 0.002 mg/mL, respectively. The ORAC and FRAP values of JPT water extract were 40.338 ± 2.273 µM of Trolox/µg of extract and 23.07 ± 1.84 mM FeSO4/mg sample, respectively. Several well-known antioxidant-related compounds including amaronols, quinic acid, gallic acid, fertaric acid, kurigalin, amlaic acid, isoterchebin, chebulagic acid, ginkgolide C, chebulinic acid, ellagic acid, and rutin were found in this extract. Treatment with JPT water extract at 1 and 5 mg/mL increased C. elegans lifespan under normal growth condition (7.26 ± 0.65 vs. 10.4 0± 0.75 (p < 0.01) and 10.00 ± 0.73 (p < 0.01) days, respectively). CONCLUSIONS: The results indicated that JPT and its herbal ingredients exhibited strong antioxidant activities, in particular the water extract of the polyherbal tonic. These findings rationalize further investigation in JPT infusion as a promising agent for anti-aging and oxidative stress prevention.


Assuntos
Antioxidantes/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/crescimento & desenvolvimento , Extratos Vegetais/farmacologia , Animais , Antioxidantes/análise , Benzopiranos/análise , Benzopiranos/farmacologia , Glucosídeos/análise , Glucosídeos/farmacologia , Longevidade/efeitos dos fármacos , Medicina Tradicional do Leste Asiático , Estresse Oxidativo/efeitos dos fármacos , Fenóis/análise , Fenóis/farmacologia , Phyllanthus emblica/química , Extratos Vegetais/análise , Terminalia/química , Tailândia
14.
Elife ; 82019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31414984

RESUMO

Innovations in metazoan development arise from evolutionary modification of gene regulatory networks (GRNs). We report widespread cryptic variation in the requirement for two key regulatory inputs, SKN-1/Nrf2 and MOM-2/Wnt, into the C. elegans endoderm GRN. While some natural isolates show a nearly absolute requirement for these two regulators, in others, most embryos differentiate endoderm in their absence. GWAS and analysis of recombinant inbred lines reveal multiple genetic regions underlying this broad phenotypic variation. We observe a reciprocal trend, in which genomic variants, or knockdown of endoderm regulatory genes, that result in a high SKN-1 requirement often show low MOM-2/Wnt requirement and vice-versa, suggesting that cryptic variation in the endoderm GRN may be tuned by opposing requirements for these two key regulatory inputs. These findings reveal that while the downstream components in the endoderm GRN are common across metazoan phylogeny, initiating regulatory inputs are remarkably plastic even within a single species.


Assuntos
Proteínas de Caenorhabditis elegans/biossíntese , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Progranulinas/biossíntese , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Variação Genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Wnt/metabolismo
15.
Cell Host Microbe ; 26(3): 400-411.e3, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31444089

RESUMO

Iron is an essential micronutrient for all forms of life; low levels of iron cause human disease, while too much iron is toxic. Low iron levels induce reactive oxygen species (ROS) by disruption of the heme and iron-sulfur cluster-dependent electron transport chain (ETC). To identify bacterial metabolites that affect development, we screened the Keio Escherichia coli collection and uncovered 244 gene deletion mutants that slow Caenorhabditis elegans development. Several of these genes encode members of the ETC cytochrome bo oxidase complex, as well as iron importers. Surprisingly, either iron or anti-oxidant supplementation reversed the developmental delay. This suggests that low bacterial iron results in high bacterial ROS and vice versa, which causes oxidative stress in C. elegans that subsequently impairs mitochondrial function and delays development. Our data indicate that the bacterial diets of C. elegans provide precisely tailored amounts of iron to support proper development.


Assuntos
Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/microbiologia , Escherichia coli/fisiologia , Ferro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Antioxidantes/metabolismo , Caenorhabditis elegans/genética , Dieta , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Escherichia coli/genética , Deleção de Genes , Interações entre Hospedeiro e Microrganismos/fisiologia , Mitocôndrias , Mutação
16.
Elife ; 82019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31264582

RESUMO

Sexual maturation must occur on a controlled developmental schedule. In mammals, Makorin3 (MKRN3) and the miRNA regulators LIN28A/B are key regulators of this process, but how they act is unclear. In C. elegans, sexual maturation of the nervous system includes the functional remodeling of postmitotic neurons and the onset of adult-specific behaviors. Here, we find that the lin-28-let-7 axis (the 'heterochronic pathway') determines the timing of these events. Upstream of lin-28, the Makorin lep-2 and the lncRNA lep-5 regulate maturation cell-autonomously, indicating that distributed clocks, not a central timer, coordinate sexual differentiation of the C. elegans nervous system. Overexpression of human MKRN3 delays aspects of C. elegans sexual maturation, suggesting the conservation of Makorin function. These studies reveal roles for a Makorin and a lncRNA in timing of sexual differentiation; moreover, they demonstrate deep conservation of the lin-28-let-7 system in controlling the functional maturation of the nervous system.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , RNA Longo não Codificante/genética , Proteínas Repressoras/genética , Ribonucleoproteínas/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Diferenciação Celular , Regulação da Expressão Gênica no Desenvolvimento , Humanos , MicroRNAs , Mutação , Sistema Nervoso/crescimento & desenvolvimento , Maturidade Sexual/genética
17.
Nat Commun ; 10(1): 3323, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31346165

RESUMO

Most manipulations that extend lifespan also increase resistance to various stress factors and environmental cues in a range of animals from yeast to mammals. However, the underlying molecular mechanisms regulating stress resistance during aging are still largely unknown. Here we identify Krüppel-like factor 1 (KLF-1) as a mediator of a cytoprotective response that dictates longevity induced by reduced mitochondrial function. A redox-regulated KLF-1 activation and transfer to the nucleus coincides with the peak of somatic mitochondrial biogenesis that occurs around a transition from larval stage L3 to D1. We further show that KLF-1 activates genes involved in the xenobiotic detoxification programme and identified cytochrome P450 oxidases, the KLF-1 main effectors, as longevity-assurance factors of mitochondrial mutants. Collectively, these findings underline the importance of the xenobiotic detoxification in the mitohormetic, longevity assurance pathway and identify KLF-1 as a central factor in orchestrating this response.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Mitocôndrias/genética , Xenobióticos/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Feminino , Inativação Metabólica , Fatores de Transcrição Kruppel-Like/genética , Longevidade , Masculino , Mitocôndrias/metabolismo
18.
Biosci Biotechnol Biochem ; 83(12): 2194-2197, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31357905

RESUMO

The nematocidal activities of the fatty acid esters of d-allose were examined using the larvae of C. elegans. Among the fatty acid esters, 6-O-octanoyl-d-allose (3) showed significant activity. 6-O-octanoyl-d-glucose (5) showed no activity, indicating that the D-allose moiety is essential for the nematocidal activity of 3. A nonhydrolyzable alkoxy analog 6-O-octyl-d-allose (6) also showed activity equivalent to that of 3.


Assuntos
Antinematódeos/farmacologia , Caenorhabditis elegans/crescimento & desenvolvimento , Glucose/farmacologia , Larva/efeitos dos fármacos , Animais , Glucose/química
19.
Genetics ; 213(2): 501-515, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31358532

RESUMO

Although multiple determinants for establishing polarity in membranes of epithelial cells have been identified, the mechanism for maintaining apicobasal polarity is not fully understood. Here, we show that the conserved Hippo kinase pathway plays a role in the maintenance of apicobasal polarity in the developing intestine of Caenorhabditis elegans We screened suppressors of the mutation in wts-1-the gene that encodes the LATS kinase homolog, deficiency of which leads to disturbance of the apicobasal polarity of the intestinal cells and to eventual death of the organism. We identified several alleles of yap-1 and egl-44 that suppress the effects of this mutation. yap-1 encodes a homolog of YAP/Yki, and egl-44 encodes a homolog of TEAD/Sd. WTS-1 bound directly to YAP-1 and inhibited its nuclear accumulation in intestinal cells. We also found that NFM-1, which is a homolog of NF2/Merlin, functioned in the same genetic pathway as WTS-1 to regulate YAP-1 to maintain cellular polarity. Transcriptome analysis identified several target candidates of the YAP-1-EGL-44 complex including TAT-2, which encodes a putative P-type ATPase. In summary, we have delineated the conserved Hippo pathway in C. elegans consisting of NFM-1-WTS-1-YAP-1-EGL-44 and proved that the proper regulation of YAP-1 by upstream NFM-1 and WTS-1 is essential for maintenance of apicobasal membrane identities of the growing intestine.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Caenorhabditis elegans/genética , Intestinos/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/genética , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Polaridade Celular/genética , Proliferação de Células/genética , Células Epiteliais/metabolismo , Humanos , Fosforilação/genética , Transdução de Sinais/genética , Transcriptoma/genética
20.
PLoS Genet ; 15(6): e1008228, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31220078

RESUMO

Dendrite growth is constrained by a self-avoidance response that induces retraction but the downstream pathways that balance these opposing mechanisms are unknown. We have proposed that the diffusible cue UNC-6(Netrin) is captured by UNC-40(DCC) for a short-range interaction with UNC-5 to trigger self-avoidance in the C. elegans PVD neuron. Here we report that the actin-polymerizing proteins UNC-34(Ena/VASP), WSP-1(WASP), UNC-73(Trio), MIG-10(Lamellipodin) and the Arp2/3 complex effect dendrite retraction in the self-avoidance response mediated by UNC-6(Netrin). The paradoxical idea that actin polymerization results in shorter rather than longer dendrites is explained by our finding that NMY-1 (non-muscle myosin II) is necessary for retraction and could therefore mediate this effect in a contractile mechanism. Our results also show that dendrite length is determined by the antagonistic effects on the actin cytoskeleton of separate sets of effectors for retraction mediated by UNC-6(Netrin) versus outgrowth promoted by the DMA-1 receptor. Thus, our findings suggest that the dendrite length depends on an intrinsic mechanism that balances distinct modes of actin assembly for growth versus retraction.


Assuntos
Actinas/genética , Proteínas de Caenorhabditis elegans/genética , Células Dendríticas/metabolismo , Netrinas/genética , Neurônios/metabolismo , Citoesqueleto de Actina/genética , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Actinas/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Membrana/genética , Cadeias Pesadas de Miosina/genética , Proteínas do Tecido Nervoso/genética , Miosina não Muscular Tipo IIB/genética
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