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1.
Nat Commun ; 12(1): 4239, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244495

RESUMO

Stable epigenetic changes appear uncommon, suggesting that changes typically dissipate or are repaired. Changes that stably alter gene expression across generations presumably require particular conditions that are currently unknown. Here we report that a minimal combination of cis-regulatory sequences can support permanent RNA silencing of a single-copy transgene and its derivatives in C. elegans simply upon mating. Mating disrupts competing RNA-based mechanisms to initiate silencing that can last for >300 generations. This stable silencing requires components of the small RNA pathway and can silence homologous sequences in trans. While animals do not recover from mating-induced silencing, they often recover from and become resistant to trans silencing. Recovery is also observed in most cases when double-stranded RNA is used to silence the same coding sequence in different regulatory contexts that drive germline expression. Therefore, we propose that regulatory features can evolve to oppose permanent and potentially maladaptive responses to transient change.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Interferência de RNA/fisiologia , RNA de Cadeia Dupla/genética , Animais , Animais Geneticamente Modificados , Feminino , Masculino , Elementos Reguladores de Transcrição , Reprodução/genética
2.
Nat Commun ; 12(1): 4212, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244496

RESUMO

CSR-1 is an essential Argonaute protein that binds to a subclass of 22G-RNAs targeting most germline-expressed genes. Here we show that the two isoforms of CSR-1 have distinct expression patterns; CSR-1B is ubiquitously expressed throughout the germline and during all stages of development while CSR-1A expression is restricted to germ cells undergoing spermatogenesis. Furthermore, CSR-1A associates preferentially with 22G-RNAs mapping to spermatogenesis-specific genes whereas CSR-1B-bound small RNAs map predominantly to oogenesis-specific genes. Interestingly, the exon unique to CSR-1A contains multiple dimethylarginine modifications, which are necessary for the preferential binding of CSR-1A to spermatogenesis-specific 22G-RNAs. Thus, we have discovered a regulatory mechanism for C. elegans Argonaute proteins that allows for specificity of small RNA binding between similar Argonaute proteins with overlapping temporal and spatial localization.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Interferência de RNA , Espermatogênese/genética , Animais , Animais Geneticamente Modificados , Arginina/metabolismo , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Éxons/genética , Feminino , Masculino , Metilação , Oogênese/genética , Ligação Proteica/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno/metabolismo , Processos de Determinação Sexual/genética
3.
Biol Lett ; 17(6): 20200916, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34102068

RESUMO

Recently, nine Caenorhabditis elegans genes, grouped into two pathways/clusters, were found to be implicated in healthspan in C. elegans and their homologues in humans, based on literature curation, WormBase data mining and bioinformatics analyses. Here, we further validated these genes experimentally in C. elegans. We downregulated the nine genes via RNA interference (RNAi), and their effects on physical function (locomotion in a swim assay) and on physiological function (survival after heat stress) were analysed in aged nematodes. Swim performance was negatively affected by the downregulation of acox-1.1, pept-1, pak-2, gsk-3 and C25G6.3 in worms with advanced age (twelfth day of adulthood) and heat stress resistance was decreased by RNAi targeting of acox-1.1, daf-22, cat-4, pig-1, pak-2, gsk-3 and C25G6.3 in moderately (seventh day of adulthood) or advanced aged nematodes. Only one gene, sad-1, could not be linked to a health-related function in C. elegans with the bioassays we selected. Thus, most of the healthspan genes could be re-confirmed by health measurements in old worms.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Estresse Fisiológico , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Humanos , Longevidade/genética
4.
Nat Commun ; 12(1): 3263, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34059684

RESUMO

A fundamental question in medical genetics is how the genetic background modifies the phenotypic outcome of mutations. We address this question by focusing on the seam cells, which display stem cell properties in the epidermis of Caenorhabditis elegans. We demonstrate that a putative null mutation in the GATA transcription factor egl-18, which is involved in seam cell fate maintenance, is more tolerated in the CB4856 isolate from Hawaii than the lab reference strain N2 from Bristol. We identify multiple quantitative trait loci (QTLs) underlying the difference in phenotype expressivity between the two isolates. These QTLs reveal cryptic genetic variation that reinforces seam cell fate through potentiating Wnt signalling. Within one QTL region, a single amino acid deletion in the heat shock protein HSP-110 in CB4856 is sufficient to modify Wnt signalling and seam cell development, highlighting that natural variation in conserved heat shock proteins can shape phenotype expressivity.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Diferenciação Celular/genética , Células Epidérmicas/fisiologia , Fatores de Transcrição GATA/genética , Proteínas de Choque Térmico HSP110/genética , Células-Tronco/fisiologia , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição GATA/metabolismo , Estudos de Associação Genética , Técnicas Genéticas , Variação Genética , Proteínas de Choque Térmico HSP110/metabolismo , Organismos Hermafroditas , Masculino , Mutação , Locos de Características Quantitativas , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Via de Sinalização Wnt/genética
5.
Int J Mol Sci ; 22(10)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064595

RESUMO

Experimental studies of Caenorhabditis elegans and Drosophila melanogaster have contributed substantially to our understanding of molecular and cellular processes in metazoans at large. Since the publication of their genomes, functional genomic investigations have identified genes that are essential or non-essential for survival in each species. Recently, a range of features linked to gene essentiality have been inferred using a machine learning (ML)-based approach, allowing essentiality predictions within a species. Nevertheless, predictions between species are still elusive. Here, we undertake a comprehensive study using ML to discover and validate features of essential genes common to both C. elegans and D. melanogaster. We demonstrate that the cross-species prediction of gene essentiality is possible using a subset of features linked to nucleotide/protein sequences, protein orthology and subcellular localisation, single-cell RNA-seq, and histone methylation markers. Complementary analyses showed that essential genes are enriched for transcription and translation functions and are preferentially located away from heterochromatin regions of C. elegans and D. melanogaster chromosomes. The present work should enable the cross-prediction of essential genes between model and non-model metazoans.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Evolução Molecular , Genes Essenciais , Aprendizado de Máquina , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Ontologia Genética , Genômica
6.
Phytomedicine ; 88: 153598, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34111615

RESUMO

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


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Depressão/genética , Estresse Fisiológico/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Antidepressivos/farmacologia , Antioxidantes/farmacologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Simulação de Acoplamento Molecular , Mutação , Estresse Oxidativo/efeitos dos fármacos , Peroxirredoxinas/genética , Substâncias Protetoras/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genética , Triterpenos/química
7.
Nat Commun ; 12(1): 3492, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108460

RESUMO

In the Caenorhabditis elegans germline, thousands of mRNAs are concomitantly expressed with antisense 22G-RNAs, which are loaded into the Argonaute CSR-1. Despite their essential functions for animal fertility and embryonic development, how CSR-1 22G-RNAs are produced remains unknown. Here, we show that CSR-1 slicer activity is primarily involved in triggering the synthesis of small RNAs on the coding sequences of germline mRNAs and post-transcriptionally regulates a fraction of targets. CSR-1-cleaved mRNAs prime the RNA-dependent RNA polymerase, EGO-1, to synthesize 22G-RNAs in phase with translating ribosomes, in contrast to other 22G-RNAs mostly synthesized in germ granules. Moreover, codon optimality and efficient translation antagonize CSR-1 slicing and 22G-RNAs biogenesis. We propose that codon usage differences encoded into mRNA sequences might be a conserved strategy in eukaryotes to regulate small RNA biogenesis and Argonaute targeting.


Assuntos
Proteínas Argonauta/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Uso do Códon , Biossíntese de Proteínas , RNA Interferente Pequeno/biossíntese , Animais , Proteínas Argonauta/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Catálise , Citosol/metabolismo , Mutação , Oogônios/metabolismo , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , RNA Polimerase Dependente de RNA/metabolismo , Ribossomos/metabolismo
8.
BMC Genomics ; 22(1): 364, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34011272

RESUMO

BACKGROUND: A healthy microbiome influences host physiology through a mutualistic relationship, which can be important for the host to cope with cellular stress by promoting fitness and survival. The mammalian microbiome is highly complex and attributing host phenotypes to a specific member of the microbiome can be difficult. The model organism Caenorhabditis elegans and its native microbiome, discovered recently, can serve as a more tractable, experimental model system to study host-microbiome interactions. In this study, we investigated whether certain members of C. elegans native microbiome would offer a benefit to their host and putative molecular mechanisms using a combination of phenotype screening, omics profiling and functional validation. RESULTS: A total of 16 members of C. elegans microbiome were screened under chemically-induced toxicity. Worms grown with Chryseobacterium sp. CHNTR56 MYb120 or Comamonas sp. 12022 MYb131, were most resistant to oxidative chemical stress (SiO2 nanoparticles and juglone), as measured by progeny output. Further investigation showed that Chryseobacterium sp. CHNTR56 positively influenced the worm's lifespan, whereas the combination of both isolates had a synergistic effect. RNAseq analysis of young adult worms, grown with either isolate, revealed the enrichment of cellular detoxification mechanisms (glutathione metabolism, drug metabolism and metabolism of xenobiotics) and signaling pathways (TGF-beta and Wnt signaling pathways). Upregulation of cysteine synthases (cysl genes) in the worms, associated with glutathione metabolism, was also observed. Nanopore sequencing uncovered that the genomes of the two isolates have evolved to favor the specific route of the de novo synthesis pathway of vitamin B6 (cofactor of cysl enzymes) through serC or pdxA2 homologs. Finally, co-culture with vitamin B6 extended worm lifespan. CONCLUSIONS: In summary, our study indicates that certain colonizing members of C. elegans have genomic diversity in vitamin B6 synthesis and promote host fitness and lifespan extension. The regulation of host cellular detoxification genes (i.e. gst) along with cysl genes at the transcriptome level and the bacterium-specific vitamin B6 synthesis mechanism at the genome level are in an agreement with enhanced host glutathione-based cellular detoxification due to this interspecies relationship. C. elegans is therefore a promising alternative model to study host-microbiome interactions in host fitness and lifespan.


Assuntos
Proteínas de Caenorhabditis elegans , Microbiota , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Longevidade , Estresse Oxidativo , Dióxido de Silício
9.
Nat Commun ; 12(1): 2668, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976151

RESUMO

Telomeres are bound by dedicated proteins, which protect them from DNA damage and regulate telomere length homeostasis. In the nematode Caenorhabditis elegans, a comprehensive understanding of the proteins interacting with the telomere sequence is lacking. Here, we harnessed a quantitative proteomics approach to identify TEBP-1 and TEBP-2, two paralogs expressed in the germline and embryogenesis that associate to telomeres in vitro and in vivo. tebp-1 and tebp-2 mutants display strikingly distinct phenotypes: tebp-1 mutants have longer telomeres than wild-type animals, while tebp-2 mutants display shorter telomeres and a Mortal Germline. Notably, tebp-1;tebp-2 double mutant animals have synthetic sterility, with germlines showing signs of severe mitotic and meiotic arrest. Furthermore, we show that POT-1 forms a telomeric complex with TEBP-1 and TEBP-2, which bridges TEBP-1/-2 with POT-2/MRT-1. These results provide insights into the composition and organization of a telomeric protein complex in C. elegans.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas de Ligação a Telômeros/metabolismo , Telômero/metabolismo , Animais , Animais Geneticamente Modificados , Sequência de Bases , Sítios de Ligação/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/classificação , Proteínas de Caenorhabditis elegans/genética , DNA/genética , Proteínas de Ligação a DNA/genética , Células Germinativas/metabolismo , Microscopia de Fluorescência/métodos , Complexos Multiproteicos/genética , Mutação , Filogenia , Ligação Proteica , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Telômero/genética , Proteínas de Ligação a Telômeros/classificação , Proteínas de Ligação a Telômeros/genética
10.
ACS Chem Neurosci ; 12(11): 2045-2056, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34019371

RESUMO

Synaptic remodeling plays important roles in health and neural disorders. Although previous studies revealed that several transcriptional programs control synaptic remodeling in the nematode Caenorhabditis elegans, the molecular mechanisms of the dorsal D-type (DD) synaptic remodeling are poorly understood. Here we show that extracellular matrix molecule muscle arm development defective protein-4 (MADD-4) cooperates with the one immunoglobulin domain protein-1 (OIG-1) to defer precocious DD synaptic remodeling. Specifically, loss of MADD-4 exhibited the precocious DD synaptic remodeling. The long isoform MADD-4L is dynamically expressed while the short isoform MADD-4B is persistently expressed in DD neurons of L1 stage. In the unc-30 mutant lacking the Pitx-type homeodomain transcription factor UNC-30, the expression levels of both MADD-4B and -L isoforms were dramatically downregulated in DD neurons of the L1 stage. Our further data showed that MADD-4B and -L isoforms physically interact with OIG-1 and madd-4 acts in the oig-1 genetic pathway to modulate the DD synaptic remodeling. Our findings demonstrated that the extracellular matrix plays a novel role in synaptic plasticity.


Assuntos
Proteínas de Caenorhabditis elegans , Proteínas do Tecido Nervoso , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Matriz Extracelular , Proteínas da Matriz Extracelular , Domínios de Imunoglobulina , Neurônios Motores
11.
Chemosphere ; 274: 129845, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33979940

RESUMO

In this work, Caenorhabditis elegans was employed as an in vivo model to determine the toxic effects of atrazine at different concentrations. After the exposure period from the larval stage L1 to adulthood day 1, atrazine (10 mg/L) significantly decreased the body length and lifespan of nematodes. In addition, exposure to ≥0.01 mg/L atrazine remarkably increased the intestinal reactive oxygen species (ROS) levels and reduced locomotion behavior of nematodes, while exposure to ≥ 1 mg/L atrazine decreased the brood size of nematodes. Moreover, atrazine (0.001-0.1 mg/L) upregulated the expression levels of hsp-6::GFP and hsp-6/60 in nematodes, indicating the activation of mitochondrial unfolded protein response (mtUPR). On the contrary, atrazine (1-10 mg/L) downregulated the expression levels of hsp-6::GFP and hsp-6/60 in nematodes. Furthermore, mtUPR induction governed by the RNAi knockdown of atfs-1 could increase the vulnerability of nematodes against atrazine toxicity. Overall, our findings highlighted the dynamic responses of nematodes toward different concentrations of atrazine, which could be monitored using different sublethal endpoints as bioindicators.


Assuntos
Atrazina , Proteínas de Caenorhabditis elegans , Animais , Atrazina/toxicidade , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Locomoção , Estresse Oxidativo , Espécies Reativas de Oxigênio
12.
eNeuro ; 8(3)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34031101

RESUMO

Restoration of lost function following a nervous system injury is limited in adulthood as the regenerative capacity of nervous system declines with age. Pharmacological approaches have not been very successful in alleviating the consequences of nervous system injury. On the contrary, physical activity and rehabilitation interventions are often beneficial to improve the health conditions in the patients with neuronal injuries. Using touch neuron circuit of Caenorhabditis elegans, we investigated the role of physical exercise in the improvement of functional restoration after axotomy. We found that a swimming session of 90 min following the axotomy of posterior lateral microtubule (PLM) neuron can improve functional recovery in larval and adult stage animals. In older age, multiple exercise sessions were required to enhance the functional recovery. Genetic analysis of axon regeneration mutants showed that exercise-mediated enhancement of functional recovery depends on the ability of axon to regenerate. Exercise promotes early initiation of regrowth, self-fusion of proximal and distal ends, as well as postregrowth enhancement of function. We further found that the swimming exercise promotes axon regeneration through the activity of cellular energy sensor AAK-2/AMPK in both muscle and neuron. Our study established a paradigm where systemic effects of exercise on functional regeneration could be addressed at the single neuron level.


Assuntos
Axônios , Proteínas de Caenorhabditis elegans , Proteínas Quinases Ativadas por AMP , Adulto , Idoso , Animais , Proteínas de Caenorhabditis elegans/genética , Humanos , Regeneração Nervosa , Natação
13.
J Virol ; 95(12)2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-33827942

RESUMO

Host-pathogen interactions play a major role in evolutionary selection and shape natural genetic variation. The genetically distinct Caenorhabditis elegans strains, Bristol N2 and Hawaiian CB4856, are differentially susceptible to the Orsay virus (OrV). Here, we report the dissection of the genetic architecture of susceptibility to OrV infection. We compare OrV infection in the relatively resistant wild-type CB4856 strain to the more susceptible canonical N2 strain. To gain insight into the genetic architecture of viral susceptibility, 52 fully sequenced recombinant inbred lines (CB4856 × N2 RILs) were exposed to OrV. This led to the identification of two loci on chromosome IV associated with OrV resistance. To verify the two loci and gain additional insight into the genetic architecture controlling virus infection, introgression lines (ILs) that together cover chromosome IV, were exposed to OrV. Of the 27 ILs used, 17 had an CB4856 introgression in an N2 background, and 10 had an N2 introgression in a CB4856 background. Infection of the ILs confirmed and fine-mapped the locus underlying variation in OrV susceptibility, and we found that a single nucleotide polymorphism in cul-6 may contribute to the difference in OrV susceptibility between N2 and CB4856. An allele swap experiment showed the strain CB4856 became as susceptible as the N2 strain by having an N2 cul-6 allele, although having the CB4856 cul-6 allele did not increase resistance in N2. In addition, we found that multiple strains with nonoverlapping introgressions showed a distinct infection phenotype from the parental strain, indicating that there are punctuated locations on chromosome IV determining OrV susceptibility. Thus, our findings reveal the genetic complexity of OrV susceptibility in C. elegans and suggest that viral susceptibility is governed by multiple genes.IMPORTANCE Genetic variation determines the viral susceptibility of hosts. Yet, pinpointing which genetic variants determine viral susceptibility remains challenging. Here, we have exploited the genetic tractability of the model organism Caenorhabditis elegans to dissect the genetic architecture of Orsay virus infection. Our results provide novel insight into natural determinants of Orsay virus infection.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/virologia , Cromossomos/genética , Proteínas Culina/genética , Variação Genética , Nodaviridae/patogenicidade , Locos de Características Quantitativas , Animais , Genes de Helmintos , Predisposição Genética para Doença , Interações Hospedeiro-Patógeno , Herança Multifatorial , Nodaviridae/fisiologia , Polimorfismo de Nucleotídeo Único , Carga Viral
14.
Nutrients ; 13(3)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802038

RESUMO

Many studies have highlighted the relationship between food and health status, with the aim of improving both disease prevention and life expectancy. Among the different food groups, fermented foods a have huge microbial biodiversity, making them an interesting source of metabolites that could exhibit health benefits. Our previous study highlighted the capacity of raw goat milk cheese, and some of the extracts recovered by the means of chemical fractionation, to increase the longevity of the nematode Caenorhabditis elegans. In this article, we pursued the investigation with a view toward understanding the biological mechanisms involved in this phenomenon. Using mutant nematode strains, we evaluated the implication of the insulin-like DAF-2/DAF-16 and the p38 MAPK pathways in the phenomenon of increased longevity and oxidative-stress resistance mechanisms. Our results demonstrated that freeze-dried raw goat milk cheese, and its extracts, induced the activation of the DAF-2/DAF-16 pathway, increasing longevity. Concerning oxidative-stress resistance, all the extracts increased the survival of the worms, but no evidence of the implication of both of the pathways was highlighted, except for the cheese-lipid extract that did seem to require both pathways to improve the survival rate. Simultaneously, the cheese-lipid extract and the dried extract W70, obtained with water, were able to reduce the reactive oxygen species (ROS) production in human leukocytes. This result is in good correlation with the results obtained with the nematode.


Assuntos
Caenorhabditis elegans/fisiologia , Queijo , Leucócitos/fisiologia , Estresse Oxidativo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Núcleo Celular/metabolismo , Sobrevivência Celular , Alimentos em Conserva , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Liofilização , Regulação da Expressão Gênica , Longevidade , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , Sistema de Sinalização das MAP Quinases , Leite , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Acetato de Tetradecanoilforbol/farmacologia
15.
Nat Commun ; 12(1): 2194, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33850152

RESUMO

Multicellularity has coincided with the evolution of microRNAs (miRNAs), small regulatory RNAs that are integrated into cellular differentiation and homeostatic gene-regulatory networks. However, the regulatory mechanisms underpinning miRNA activity have remained largely obscured because of the precise, and thus difficult to access, cellular contexts under which they operate. To resolve these, we have generated a genome-wide map of active miRNAs in Caenorhabditis elegans by revealing cell-type-specific patterns of miRNAs loaded into Argonaute (AGO) silencing complexes. Epitope-labelled AGO proteins were selectively expressed and immunoprecipitated from three distinct tissue types and associated miRNAs sequenced. In addition to providing information on biological function, we define adaptable miRNA:AGO interactions with single-cell-type and AGO-specific resolution. We demonstrate spatial and temporal dynamicism, flexibility of miRNA loading, and suggest miRNA regulatory mechanisms via AGO selectivity in different tissues and during ageing. Additionally, we resolve widespread changes in AGO-regulated gene expression by analysing translatomes specifically in neurons.


Assuntos
Proteínas Argonauta/genética , Proteínas Argonauta/metabolismo , Caenorhabditis elegans/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Regulação da Expressão Gênica , Sistema Nervoso , Isoformas de Proteínas
16.
J Proteomics ; 240: 104222, 2021 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-33831597

RESUMO

Wound repair is a multistep process which involves coordination of multiple molecular players from different cell types and pathways. Though the cellular processes that are taking place in order to repair damage is already known, molecular players involved in crucial pathways are still scarce. In this regard, the present study intends to uncover crucial players that are involved in the central repair events through proteomics approach which included 2-D GE and LC-MS/MS using Caenorhabditis elegans wound model. Initial gel-based 2-D GE and following protein-protein interaction (PPI) network analyses revealed active role of calcium signaling, acetylcholine transport and serotonergic neurotransmitter pathways. Further, gel-free LC-MS/MS and following PPI network analyses revealed the incidence of actin nucleation at the initial hours immediately after injury. Further by visualizing the PPI network and the interacting players, pink-1, a mitochondrial Serine/threonine-protein kinase which is known to regulate mitochondrial dynamics, was found to be the central player in facilitating the mitochondrial fission and its role was further verified using qPCR analysis and pink-1 transgenic worms. Overall, the study delivers new insights from crucial regulatory pathways and central players involved in wound repair using high throughput proteomic approaches and the mass spectrometry Data (PXD024629/PXD024744) are available via ProteomeXchange. SIGNIFICANCE.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Proteínas de Caenorhabditis elegans/genética , Cromatografia Líquida , Proteômica , Espectrometria de Massas em Tandem
17.
Molecules ; 26(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: covidwho-1167670

RESUMO

Depression and anxiety disorders are widespread diseases, and they belong to the leading causes of disability and greatest burdens on healthcare systems worldwide. It is expected that the numbers will dramatically rise during the COVID-19 pandemic. Established medications are not sufficient to adequately treat depression and are not available for everyone. Plants from traditional medicine may be promising alternatives to treat depressive symptoms. The model organism Chaenorhabditis elegans was used to assess the stress reducing effects of methanol/dichlormethane extracts from plants used in traditional medicine. After initial screening for antioxidant activity, nine extracts were selected for in vivo testing in oxidative stress, heat stress, and osmotic stress assays. Additionally, anti-aging properties were evaluated in lifespan assay. The extracts from Acanthopanax senticosus, Campsis grandiflora, Centella asiatica, Corydalis yanhusuo, Dan Zhi, Houttuynia cordata, Psoralea corylifolia, Valeriana officinalis, and Withaniasomnifera showed antioxidant activity of more than 15 Trolox equivalents per mg extract. The extracts significantly lowered ROS in mutants, increased resistance to heat stress and osmotic stress, and the extended lifespan of the nematodes. The plant extracts tested showed promising results in increasing stress resistance in the nematode model. Further analyses are needed, in order to unravel underlying mechanisms and transfer results to humans.


Assuntos
Antidepressivos/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Animais , Antioxidantes/farmacologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Técnicas de Inativação de Genes , Resposta ao Choque Térmico/efeitos dos fármacos , Longevidade/efeitos dos fármacos , Longevidade/genética , Longevidade/fisiologia , Mutação , Pressão Osmótica/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Espécies Reativas de Oxigênio/metabolismo
18.
Genes Cells ; 26(6): 411-425, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33817914

RESUMO

Interneurons, innervated by multiple sensory neurons, need to integrate information from these sensory neurons and respond to sensory stimuli adequately. Mechanisms how sensory information is integrated to form responses of interneurons are not fully understood. In Caenorhabditis elegans, loss-of-function mutations of egl-4, which encodes a cGMP-dependent protein kinase (PKG), cause a defect in chemotaxis to odorants. Our genetic and imaging analyses revealed that the response property of AIY interneuron to an odorant is reversed in the egl-4 mutant, while the responses of two upstream olfactory neurons, AWA and AWC, are largely unchanged. Cell- ablation experiments show that AIY in the egl-4 mutant functions to suppress chemotaxis. Furthermore, the reversal of AIY response occurs only in the presence of sensory signals from both AWA and AWC. These results suggest that sensory signals are inadequately integrated in the egl-4 mutant. We also show that egl-4 expression in AWA and another sensory neuron prevents the reversed AIY response and restores chemotaxis in the egl-4 mutants. We propose that EGL-4/PKG, by suppressing aberrant integration of signals from olfactory neurons, converts the response property of an interneuron to olfactory stimuli and maintains the role of the interneuron in the circuit to execute chemotactic behavior.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/citologia , Caenorhabditis elegans/metabolismo , Quimiotaxia , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Interneurônios/metabolismo , Sensação , Animais , Proteínas de Caenorhabditis elegans/genética , Cálcio/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/genética , Interneurônios/citologia , Mutação/genética , Neurônios Receptores Olfatórios/metabolismo , Pentanóis/farmacologia , Células Receptoras Sensoriais/metabolismo
19.
G3 (Bethesda) ; 11(3)2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33890616

RESUMO

The let-7 gene encodes a highly conserved microRNA with critical functions integral to cell fate specification and developmental progression in diverse animals. In Caenorhabditis elegans, let-7 is a component of the heterochronic (developmental timing) gene regulatory network, and loss-of-function mutations of let-7 result in lethality during the larval to adult transition due to misregulation of the conserved let-7 target, lin-41. To date, no bilaterian animal lacking let-7 has been characterized. In this study, we identify a cohort of nematode species within the genus Caenorhabditis, closely related to C. elegans, that lack the let-7 microRNA, owing to absence of the let-7 gene. Using Caenorhabditis sulstoni as a representative let-7-lacking species to characterize normal larval development in the absence of let-7, we demonstrate that, except for the lack of let-7, the heterochronic gene network is otherwise functionally conserved. We also report that species lacking let-7 contain a group of divergent let-7 paralogs-also known as the let-7-family of microRNAs-that have apparently assumed the role of targeting the LIN-41 mRNA.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , MicroRNAs/genética , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição/genética
20.
Molecules ; 26(8)2021 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-33920352

RESUMO

The pathological finding of amyloid-ß (Aß) aggregates is thought to be a leading cause of untreated Alzheimer's disease (AD). In this study, we isolated 2-butoxytetrahydrofuran (2-BTHF), a small cyclic ether, from Holothuria scabra and demonstrated its therapeutic potential against AD through the attenuation of Aß aggregation in a transgenic Caenorhabditis elegans model. Our results revealed that amongst the five H. scabra isolated compounds, 2-BTHF was shown to be the most effective in suppressing worm paralysis caused by Aß toxicity and in expressing strong neuroprotection in CL4176 and CL2355 strains, respectively. An immunoblot analysis showed that CL4176 and CL2006 treated with 2-BTHF showed no effect on the level of Aß monomers but significantly reduced the toxic oligomeric form and the amount of 1,4-bis(3-carboxy-hydroxy-phenylethenyl)-benzene (X-34)-positive fibril deposits. This concurrently occurred with a reduction of reactive oxygen species (ROS) in the treated CL4176 worms. Mechanistically, heat shock factor 1 (HSF-1) (at residues histidine 63 (HIS63) and glutamine 72 (GLN72)) was shown to be 2-BTHF's potential target that might contribute to an increased expression of autophagy-related genes required for the breakdown of the Aß aggregate, thus attenuating its toxicity. In conclusion, 2-BTHF from H. scabra could protect C. elegans from Aß toxicity by suppressing its aggregation via an HSF-1-regulated autophagic pathway and has been implicated as a potential drug for AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Furanos/farmacologia , Holothuria/química , Fármacos Neuroprotetores/farmacologia , Paralisia/prevenção & controle , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Sítios de Ligação , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/antagonistas & inibidores , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Furanos/química , Furanos/isolamento & purificação , Regulação da Expressão Gênica , Humanos , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/isolamento & purificação , Paralisia/genética , Paralisia/metabolismo , Paralisia/patologia , Agregados Proteicos/efeitos dos fármacos , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
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