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1.
Adv Exp Med Biol ; 1178: 247-264, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31493231

RESUMO

Although human life expectancy has increased significantly over the last two centuries, this has not been paralleled by a similar rise in healthy life expectancy. Thus, an important goal of anti-aging research has been to reduce the impact of age-associated diseases as a way of extending the human healthspan. This review will explore some of the potential avenues which have emerged from this research as the most promising strategies and drug targets for therapeutic interventions to promote healthy aging.


Assuntos
Envelhecimento , Biomarcadores , Longevidade , Envelhecimento/fisiologia , Animais , Biomarcadores/análise , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Humanos , Longevidade/fisiologia , Pesquisa/tendências
2.
3.
Chem Commun (Camb) ; 55(68): 10142-10145, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389424

RESUMO

Hydrogen sulfide, an endogenous signalling molecule, is central to several pathophysiological processes in mammalian systems. It scavenges reactive oxygen species and is known to ameliorate dopaminergic neuronal degeneration in neurotoxin-induced Parkinson's disease models. The rapid volatilization of H2S from spontaneously releasing sulfide salts being a challenge, we describe peptide conjugates which exhibit tris(2-carboxyethyl)phosphine mediated "slow and sustained" H2S release. These conjugates reduced hydrogen peroxide-induced oxidative stress and significantly increased dopamine levels in transgenic C. elegans.


Assuntos
Dopamina/metabolismo , Sulfeto de Hidrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/farmacologia , Tionas/farmacologia , Tiofenos/farmacologia , Animais , Animais Geneticamente Modificados , Anti-Inflamatórios/metabolismo , Antioxidantes/metabolismo , Caenorhabditis elegans/genética , Liberação Controlada de Fármacos , Oxirredução , Peptídeos/síntese química , Peptídeos/química , Fosfinas/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tionas/síntese química , Tionas/química , Tiofenos/síntese química , Tiofenos/química , alfa-Sinucleína/genética
4.
Genes Dev ; 33(17-18): 1191-1207, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371435

RESUMO

The vast majority of eukaryotes possess two DNA recombinases: Rad51, which is ubiquitously expressed, and Dmc1, which is meiosis-specific. The evolutionary origins of this two-recombinase system remain poorly understood. Interestingly, Dmc1 can stabilize mismatch-containing base triplets, whereas Rad51 cannot. Here, we demonstrate that this difference can be attributed to three amino acids conserved only within the Dmc1 lineage of the Rad51/RecA family. Chimeric Rad51 mutants harboring Dmc1-specific amino acids gain the ability to stabilize heteroduplex DNA joints with mismatch-containing base triplets, whereas Dmc1 mutants with Rad51-specific amino acids lose this ability. Remarkably, RAD-51 from Caenorhabditis elegans, an organism without Dmc1, has acquired "Dmc1-like" amino acids. Chimeric C. elegans RAD-51 harboring "canonical" Rad51 amino acids gives rise to toxic recombination intermediates, which must be actively dismantled to permit normal meiotic progression. We propose that Dmc1 lineage-specific amino acids involved in the stabilization of heteroduplex DNA joints with mismatch-containing base triplets may contribute to normal meiotic recombination.


Assuntos
Aminoácidos/metabolismo , Rad51 Recombinase/química , Rad51 Recombinase/metabolismo , Recombinases/química , Recombinases/metabolismo , Recombinação Genética/genética , Aminoácidos/genética , Animais , Pareamento Incorreto de Bases , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Sequência Conservada , Mutação , Rad51 Recombinase/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Recombinases/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
5.
Nat Commun ; 10(1): 2902, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263173

RESUMO

Exogenous metabolites from microbial and dietary origins have profound effects on host metabolism. Here, we report that a sub-population of lipid droplets (LDs), which are conserved organelles for fat storage, is defined by metabolite-modulated targeting of the C. elegans seipin ortholog, SEIP-1. Loss of SEIP-1 function reduces the size of a subset of LDs while over-expression of SEIP-1 has the opposite effect. Ultrastructural analysis reveals SEIP-1 enrichment in an endoplasmic reticulum (ER) subdomain, which co-purifies with LDs. Analyses of C. elegans and bacterial genetic mutants indicate a requirement of polyunsaturated fatty acids (PUFAs) and microbial cyclopropane fatty acids (CFAs) for SEIP-1 enrichment, as confirmed by dietary supplementation experiments. In mammalian cells, heterologously expressed SEIP-1 engages nascent lipid droplets and promotes their subsequent expansion in a conserved manner. Our results suggest that microbial and polyunsaturated fatty acids serve unexpected roles in regulating cellular fat storage by promoting LD diversity.


Assuntos
Caenorhabditis elegans/metabolismo , Retículo Endoplasmático/metabolismo , Ácidos Graxos/metabolismo , Gotículas Lipídicas/metabolismo , Animais , Caenorhabditis elegans/química , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Linhagem Celular , Retículo Endoplasmático/química , Retículo Endoplasmático/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Humanos , Transporte Proteico
6.
J Agric Food Chem ; 67(33): 9277-9285, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31353906

RESUMO

3,3'-Diindolylmethane (DIM), a digestive metabolite originating from cruciferous vegetables, has dietary potential for the treatment of various human intestinal diseases. Although intestinal permeability dysfunction is closely related to the initiation and progression of human intestinal inflammatory diseases (IBDs), the effect of DIM on intestinal permeability is unclear. We evaluated the effect of DIM on the intestinal permeability of human intestinal cell monolayers and the animal model Caenorhabditis elegans, which were treated with IL-1ß and Pseudomonas aeruginosa, respectively, to mimic IBD conditions. DIM substantially restored the intestinal permeability of differentiated Caco-2 cells by enhancing the expression of tight junction proteins (including occludin and ZO-1). Compared to the IL-1ß single treatment (551.0 ± 49.0 Ω·cm2), DIM (10 µM) significantly increased the transepithelial electrical resistance (TEER) of Caco-2 cell monolayers (919.0 ± 66.4 Ω·cm2, p < 0.001). DIM also ameliorated the impaired intestinal permeability and extended the lifespan of C. elegans fed P. aeruginosa. The mean lifespan of DIM-treated worms (10.8 ± 1.3 days) was higher than that of control-treated worms (9.7 ± 1.1 days, p < 0.01). Thus, DIM is a potential nutraceutical candidate for the treatment of leaky gut syndrome by improving intestinal permeability.


Assuntos
Indóis/administração & dosagem , Doenças Inflamatórias Intestinais/tratamento farmacológico , Mucosa Intestinal/efeitos dos fármacos , Animais , Células CACO-2 , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Mucosa Intestinal/metabolismo , Intestinos , Masculino , Ocludina/genética , Ocludina/metabolismo , Permeabilidade/efeitos dos fármacos , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismo
7.
BMC Biol ; 17(1): 56, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31311534

RESUMO

BACKGROUND: Adaptive responses to stress are essential for cell and organismal survival. In metazoans, little is known about the impact of environmental stress on RNA homeostasis. RESULTS: By studying the regulation of a cadmium-induced gene named numr-1 in Caenorhabditis elegans, we discovered that disruption of RNA processing acts as a signal for environmental stress. We find that NUMR-1 contains motifs common to RNA splicing factors and influences RNA splicing in vivo. A genome-wide screen reveals that numr-1 is strongly and specifically induced by silencing of genes that function in basal RNA metabolism including subunits of the metazoan integrator complex. Human integrator processes snRNAs for functioning with splicing factors, and we find that silencing of C. elegans integrator subunits disrupts snRNA processing, causes aberrant pre-mRNA splicing, and induces the heat shock response. Cadmium, which also strongly induces numr-1, has similar effects on RNA and the heat shock response. Lastly, we find that heat shock factor-1 is required for full numr-1 induction by cadmium. CONCLUSION: Our results are consistent with a model in which disruption of integrator processing of RNA acts as a molecular damage signal initiating an adaptive stress response mediated by heat shock factor-1. When numr-1 is induced via this pathway in C. elegans, its function in RNA metabolism may allow it to mitigate further damage and thereby promote tolerance to cadmium.


Assuntos
Cádmio/toxicidade , Caenorhabditis elegans/fisiologia , Regulação da Expressão Gênica , Resposta ao Choque Térmico/fisiologia , Processamento Pós-Transcricional do RNA/fisiologia , Processamento de RNA , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Resposta ao Choque Térmico/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , RNA Nuclear Pequeno/genética , RNA Nuclear Pequeno/metabolismo , Estresse Fisiológico
8.
BMC Bioinformatics ; 20(1): 352, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31226925

RESUMO

BACKGROUND: Third-generation sequencing platforms, such as PacBio sequencing, have been developed rapidly in recent years. PacBio sequencing generates much longer reads than the second-generation sequencing (or the next generation sequencing, NGS) technologies and it has unique sequencing error patterns. An effective read simulator is essential to evaluate and promote the development of new bioinformatics tools for PacBio sequencing data analysis. RESULTS: We developed a new PacBio Sequencing Simulator (PaSS). It can learn sequence patterns from PacBio sequencing data currently available. In addition to the distribution of read lengths and error rates, we included a context-specific sequencing error model. Compared to existing PacBio sequencing simulators such as PBSIM, LongISLND and NPBSS, PaSS performed better in many aspects. Assembly tests also suggest that reads simulated by PaSS are the most similar to experimental sequencing data. CONCLUSION: PaSS is an effective sequence simulator for PacBio sequencing. It will facilitate the evaluation and development of new analysis tools for the third-generation sequencing data.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA , Software , Animais , Arabidopsis/genética , Caenorhabditis elegans/genética , Simulação por Computador , Escherichia coli/genética
9.
Nat Commun ; 10(1): 2680, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31213597

RESUMO

Genetic studies of complex traits in animals have been hindered by the need to generate, maintain, and phenotype large panels of recombinant lines. We developed a new method, C. elegans eXtreme Quantitative Trait Locus (ceX-QTL) mapping, that overcomes this obstacle via bulk selection on millions of unique recombinant individuals. We use ceX-QTL to map a drug resistance locus with high resolution. We also map differences in gene expression in live worms and discovered that mutations in the co-chaperone sti-1 upregulate the transcription of HSP-90. Lastly, we use ceX-QTL to map loci that influence fitness genome-wide confirming previously reported causal variants and uncovering new fitness loci. ceX-QTL is fast, powerful and cost-effective, and will accelerate the study of complex traits in animals.


Assuntos
Caenorhabditis elegans/genética , Mapeamento Cromossômico/métodos , Aptidão Genética/genética , Locos de Características Quantitativas/genética , Característica Quantitativa Herdável , Animais , Mapeamento Cromossômico/economia , Resistência a Medicamentos/genética , Feminino , Regulação da Expressão Gênica/genética , Masculino , Fatores de Tempo
10.
Genes Dev ; 33(13-14): 857-870, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31147388

RESUMO

Piwi proteins are important for germ cell development in most animals. These proteins are guided to specific targets by small guide RNAs, referred to as piRNAs or 21U RNAs in Caenorhabditis elegans In this organism, even though genetic screens have uncovered 21U RNA biogenesis factors, little is known about how these factors interact or what they do. Based on the previously identified 21U biogenesis factor PID-1 (piRNA-induced silencing-defective 1), we here define a novel protein complex, PETISCO (PID-3, ERH-2, TOFU-6, and IFE-3 small RNA complex), that is required for 21U RNA biogenesis. PETISCO contains both potential 5' cap and 5' phosphate RNA-binding domains and interacts with capped 21U precursor RNA. We resolved the architecture of PETISCO and revealed a second function for PETISCO in embryonic development. This essential function of PETISCO is mediated not by PID-1 but by the novel protein TOST-1 (twenty-one U pathway antagonist). In contrast, TOST-1 is not essential for 21U RNA biogenesis. Both PID-1 and TOST-1 interact directly with ERH-2 using a conserved sequence motif. Finally, our data suggest a role for TOST-1:PETISCO in SL1 homeostasis in the early embryo. Our work describes a key complex for 21U RNA processing in C. elegans and strengthens the view that 21U RNA biogenesis is built on an snRNA-related pathway.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Embrião não Mamífero/fisiologia , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , RNA Nucleolar Pequeno/biossíntese , Animais , RNA Nuclear Pequeno/metabolismo
11.
Lab Anim (NY) ; 48(7): 207-216, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31217565

RESUMO

Deep phenotyping is an emerging conceptual paradigm and experimental approach aimed at measuring and linking many aspects of a phenotype to understand its underlying biology. To date, deep phenotyping has been applied mostly in cultured cells and used less in multicellular organisms. However, in the past decade, it has increasingly been recognized that deep phenotyping could lead to a better understanding of how genetics, environment and stochasticity affect the development, physiology and behavior of an organism. The nematode Caenorhabditis elegans is an invaluable model system for studying how genes affect a phenotypic trait, and new technologies have taken advantage of the worm's physical attributes to increase the throughput and informational content of experiments. Coupling of these technical advancements with computational and analytical tools has enabled a boom in deep-phenotyping studies of C. elegans. In this Review, we highlight how these new technologies and tools are digging into the biological origins of complex, multidimensional phenotypes.


Assuntos
Caenorhabditis elegans/genética , Técnicas Genéticas , Ciência dos Animais de Laboratório/métodos , Fenótipo , Animais , Técnicas Genéticas/instrumentação , Ciência dos Animais de Laboratório/instrumentação
12.
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
13.
PLoS Genet ; 15(6): e1008242, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31246952

RESUMO

Low oxygen conditions (hypoxia) can impair essential physiological processes and cause cellular damage and death. We have shown that specific hypoxic conditions disrupt protein homeostasis in C. elegans, leading to protein aggregation and proteotoxicity. Here, we show that nutritional cues regulate this effect of hypoxia on proteostasis. Animals fasted prior to hypoxic exposure develop dramatically fewer polyglutamine protein aggregates compared to their fed counterparts, indicating that the effect of hypoxia is abrogated. Fasting also reduced the hypoxia-induced exaggeration of proteostasis defects in animals that express Aß1-42 and in animals with a temperature-sensitive mutation in dyn-1, suggesting that this effect was not specific to polyglutamine proteins. Our data also demonstrate that the nutritional environment experienced at the onset of hypoxia dictates at least some aspects of the physiological response to hypoxia. We further demonstrate that the insulin/IGF-like signaling pathway plays a role in mediating the protective effects of fasting in hypoxia. Animals with mutations in daf-2, the C. elegans insulin-like receptor, display wild-type levels of hypoxia-induced protein aggregation upon exposure to hypoxia when fed, but are not protected by fasting. DAF-2 acts independently of the FOXO transcription factor, DAF-16, to mediate the protective effects of fasting. These results suggest a non-canonical role for the insulin/IGF-like signaling pathway in coordinating the effects of hypoxia and nutritional state on proteostasis.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Fatores de Transcrição Forkhead/genética , Fator de Crescimento Insulin-Like I/genética , Insulina/genética , Receptor de Insulina/genética , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Jejum/metabolismo , Regulação da Expressão Gênica/genética , Hipóxia/genética , Hipóxia/metabolismo , Mutação/genética , Peptídeos/genética , Transdução de Sinais/genética
14.
PLoS Genet ; 15(6): e1007960, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31233487

RESUMO

UNC-6/Netrin is a conserved axon guidance cue that directs growth cone migrations in the dorsal-ventral axis of C. elegans and in the vertebrate spinal cord. UNC-6/Netrin is expressed in ventral cells, and growth cones migrate ventrally toward or dorsally away from UNC-6/Netrin. Recent studies of growth cone behavior during outgrowth in vivo in C. elegans have led to a polarity/protrusion model in directed growth cone migration away from UNC-6/Netrin. In this model, UNC-6/Netrin first polarizes the growth cone via the UNC-5 receptor, leading to dorsally biased protrusion and F-actin accumulation. UNC-6/Netrin then regulates protrusion based on this polarity. The receptor UNC-40/DCC drives protrusion dorsally, away from the UNC-6/Netrin source, and the UNC-5 receptor inhibits protrusion ventrally, near the UNC-6/Netrin source, resulting in dorsal migration. UNC-5 inhibits protrusion in part by excluding microtubules from the growth cone, which are pro-protrusive. Here we report that the RHO-1/RhoA GTPase and its activator GEF RHGF-1 inhibit growth cone protrusion and MT accumulation in growth cones, similar to UNC-5. However, growth cone polarity of protrusion and F-actin were unaffected by RHO-1 and RHGF-1. Thus, RHO-1 signaling acts specifically as a negative regulator of protrusion and MT accumulation, and not polarity. Genetic interactions are consistent with RHO-1 and RHGF-1 acting with UNC-5, as well as with a parallel pathway, to regulate protrusion. The cytoskeletal interacting molecule UNC-33/CRMP was required for RHO-1 activity to inhibit MT accumulation, suggesting that UNC-33/CRMP might act downstream of RHO-1. In sum, these studies describe a new role of RHO-1 and RHGF-1 in regulation of growth cone protrusion by UNC-6/Netrin.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Netrinas/genética , Neurônios/metabolismo , Proteínas rho de Ligação ao GTP/genética , Animais , Orientação de Axônios/genética , Axônios/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Movimento Celular/genética , Polaridade Celular/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Cones de Crescimento/metabolismo , Microtúbulos/genética , Fatores de Crescimento Neural/genética , Fenótipo , Pseudópodes/genética , Receptores de Superfície Celular/genética , Transdução de Sinais/genética
15.
BMC Genomics ; 20(1): 427, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138122

RESUMO

BACKGROUND: The two Caenorhabditis elegans somatic gonadal precursors (SGPs) are multipotent progenitors that generate all somatic tissues of the adult reproductive system. The sister cells of the SGPs are two head mesodermal cells (hmcs); one hmc dies by programmed cell death and the other terminally differentiates. Thus, a single cell division gives rise to one multipotent progenitor and one differentiated cell with identical lineage histories. We compared the transcriptomes of SGPs and hmcs in order to learn the determinants of multipotency and differentiation in this lineage. RESULTS: We generated a strain that expressed fluorescent markers specifically in SGPs (ehn-3A::tdTomato) and hmcs (bgal-1::GFP). We dissociated cells from animals after the SGP/hmc cell division, but before the SGPs had further divided, and subjected the dissociated cells to fluorescence-activated cell sorting to collect isolated SGPs and hmcs. We analyzed the transcriptomes of these cells and found that 5912 transcripts were significantly differentially expressed, with at least two-fold change in expression, between the two cell types. The hmc-biased genes were enriched with those that are characteristic of neurons. The SGP-biased genes were enriched with those indicative of cell proliferation and development. We assessed the validity of our differentially expressed genes by examining existing reporters for five of the 10 genes with the most significantly biased expression in SGPs and found that two showed expression in SGPs. For one reporter that did not show expression in SGPs, we generated a GFP knock-in using CRISPR/Cas9. This reporter, in the native genomic context, was expressed in SGPs. CONCLUSIONS: We found that the transcriptional profiles of SGPs and hmcs are strikingly different. The hmc-biased genes are enriched with those that encode synaptic transmission machinery, which strongly suggests that it has neuron-like signaling properties. In contrast, the SGP-biased genes are enriched with genes that encode factors involved in transcription and translation, as would be expected from a cell preparing to undergo proliferative divisions. Mediators of multipotency are likely to be among the genes differentially expressed in SGPs.


Assuntos
Caenorhabditis elegans/genética , Células-Tronco Multipotentes/metabolismo , Animais , Caenorhabditis elegans/metabolismo , Diferenciação Celular , Perfilação da Expressão Gênica , Gônadas/citologia , Mesoderma/citologia , RNA Mensageiro/metabolismo
16.
Cell Mol Life Sci ; 76(20): 4131-4144, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31053883

RESUMO

ABCB6 belongs to the family of ATP-binding cassette (ABC) transporters, which transport various molecules across extra- and intra-cellular membranes, bearing significant impact on human disease and pharmacology. Although mutations in the ABCB6 gene have been linked to a variety of pathophysiological conditions ranging from transfusion incompatibility to pigmentation defects, its precise cellular localization and function is not understood. In particular, the intracellular localization of ABCB6 has been a matter of debate, with conflicting reports suggesting mitochondrial or endolysosomal expression. ABCB6 shows significant sequence identity to HMT-1 (heavy metal tolerance factor 1) proteins, whose evolutionarily conserved role is to confer tolerance to heavy metals through the intracellular sequestration of metal complexes. Here, we show that the cadmium-sensitive phenotype of Schizosaccharomyces pombe and Caenorhabditis elegans strains defective for HMT-1 is rescued by the human ABCB6 protein. Overexpression of ABCB6 conferred tolerance to cadmium and As(III) (As2O3), but not to As(V) (Na2HAsO4), Sb(V), Hg(II), or Zn(II). Inactivating mutations of ABCB6 abolished vacuolar sequestration of cadmium, effectively suppressing the cadmium tolerance phenotype. Modulation of ABCB6 expression levels in human glioblastoma cells resulted in a concomitant change in cadmium sensitivity. Our findings reveal ABCB6 as a functional homologue of the HMT-1 proteins, linking endolysosomal ABCB6 to the highly conserved mechanism of intracellular cadmium detoxification.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Cádmio/toxicidade , Proteínas de Caenorhabditis elegans/genética , Inativação Metabólica/genética , Poluentes Químicos da Água/toxicidade , Transportadores de Cassetes de Ligação de ATP/deficiência , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Antimônio/toxicidade , Arseniatos/toxicidade , Trióxido de Arsênio/toxicidade , Cádmio/metabolismo , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Linhagem Celular Tumoral , Sequência Conservada , Expressão Gênica , Teste de Complementação Genética , Células HeLa , Humanos , Mercúrio/toxicidade , Mutação , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Schizosaccharomyces/efeitos dos fármacos , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Vacúolos/efeitos dos fármacos , Vacúolos/metabolismo , Poluentes Químicos da Água/metabolismo , Zinco/toxicidade
17.
RNA ; 25(8): 963-974, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31110136

RESUMO

In the course of identifying and cleaving RNA, the RNAi machinery must encounter and contend with the megadalton-sized ribosomes that carry out translation. We investigated this interface by examining the fate of actively translated mRNAs subjected to RNAi in C. elegans Quantifying RNA levels (RNA-seq) and ongoing translation (Ribo-seq), we found there is a greater fold repression of ongoing translation than expected from loss of RNA alone, observing stronger translation repression relative to RNA repression for multiple, independent double-stranded RNA triggers, and for multiple genes. In animals that lack the RNA helicase SKI complex and the ribosome rescue factor PELOTA, ribosomes stall on the 3' edges of mRNAs at and upstream of the RNAi trigger. One model to explain these observations is that ribosomes are actively cleared from mRNAs by SKI and PELO during or following mRNA cleavage. Our results expand prior studies that show a role for the SKI RNA helicase complex in removing RNA targets following RNAi in flies and plants, illuminating the widespread role of the nonstop translation surveillance in RNA silencing during RNAi. Our results are also consistent with proposals that RNAi can attack messages during active translation.


Assuntos
Caenorhabditis elegans/genética , RNA Mensageiro/genética , Ribossomos/metabolismo , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Endonucleases/metabolismo , Interferência de RNA , RNA de Helmintos/genética , RNA de Helmintos/metabolismo , RNA Mensageiro/metabolismo , Análise de Sequência de RNA
18.
Med Ref Serv Q ; 38(1): 70-80, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30942676

RESUMO

WormBase is an open-access model-organism database that provides current and accurate genetic information of C. elegans and related nematodes. Users can search WormBase by several fields, including a gene or human disease. A special feature of the database is the inclusion of micropublications, peer-reviewed data that may go unpublished in traditional venues.


Assuntos
Caenorhabditis elegans/genética , Bases de Dados Factuais/normas , Armazenamento e Recuperação da Informação/normas , Internet , Modelos Animais , Interface Usuário-Computador , Animais , California , Europa (Continente) , Humanos , Ontário
19.
J Agric Food Chem ; 67(17): 4774-4781, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30963762

RESUMO

Targeted analysis of Coffea arabica and Coffea canephora green coffees (total sample size n = 57) confirmed 2- O-ß-d-glucopyranosyl-carboxyatractyligenin (6) as the quantitatively dominating carboxyatractyligenin derivative. Its abundance in Arabicas (2425 ± 549 nmol/g, n = 48) exceeded that in Robustas (34 ± 12 nmol/g, n = 9) roughly by a factor of 70. Coffee processing involving heat (e.g., steam treatment and decaffeination) reduced concentrations of 6 and increased those of the decarboxylated derivative. The bioavailability of compound 6 in Caenorhabditis elegans was demonstrated by ultraperformance liquid chromatography-tandem mass spectrometry analysis of extracts prepared from nematode cultures incubated in a liquid medium containing 6. A toxicity assay performed to assess the impact of 6 in vivo showed a 20-fold higher median lethal dose (LD50 = 11.7 ± 1.2 mM) concentration compared to that of the known phytotoxic adenine-nucleotide transporters inhibitor carboxyatractyloside (2, LD50 = 0.61 ± 0.05 mM), whereas 1 mM 6 and 0.1 mM 2 were sufficient to decrease the survival of wild type C. elegans, already 10-20-fold lower doses reduced reproduction. Because the insulin/insulin-like growth factors signaling cascade (IIS) is a key regulator of life span and stress resistance, the impact of compound 6 on the survival of long-living daf-2 C. elegans was tested. As the susceptibility of these nematodes to 6 was as high as that in wild type, an impact on central metabolic processes independent of IIS was suggested. Analysis of the in vivo adenosine triphosphate (ATP) content of adult C. elegans revealed no changes after 1 and 24 h, but a 50% reduction after treatment with 1 mM 6 during the entire postembryonic development. These data speak for a developmental-stage-dependent modulation of the ATP pool by 6.


Assuntos
Atractilosídeo/análogos & derivados , Caenorhabditis elegans/efeitos dos fármacos , Coffea/química , Preparações de Plantas/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Atractilosídeo/farmacocinética , Atractilosídeo/farmacologia , Disponibilidade Biológica , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Coffea/toxicidade , Café/química , Feminino , Insulina/genética , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Dose Letal Mediana , Masculino
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