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1.
Ecotoxicol Environ Saf ; 208: 111579, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396102

RESUMO

Studies about radiation damage in vivo are very significant for healthy risk assessment as well as cancer radiotherapy. Ceramide as a second messenger has been found to be related to radiation-induced apoptosis. However, the detailed mechanisms in living systems are still not fully understood. In the present study, the effects of ceramide in gamma radiation-induced response were investigated using Caenorhabditis elegans. Our results indicated that ceramide was required for gamma radiation-induced whole-body germ cell apoptosis by the production of radical oxygen species and decrease of mitochondrial transmembrane potential. Using genetic ceramide synthase-related mutated strains and exogenous C16-ceramide, we illustrated that ceramide could regulate DNA damage response (DDR) pathway to mediate radiation-induced germ cell apoptosis. Moreover, ceramide was found to function epistatic to pmk-1 and mpk-1 in MAPK pathway to promote radiation-induced apoptosis in Caenorhabditis elegans. These results demonstrated ceramide could potentially mediated gamma radiation-induced apoptosis through regulating mitochondrial function, DDR pathway and MAPK pathway.


Assuntos
Caenorhabditis elegans/fisiologia , Ceramidas/farmacologia , Protetores contra Radiação/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/efeitos da radiação , Proteínas de Caenorhabditis elegans/genética , Ceramidas/metabolismo , Dano ao DNA , Células Germinativas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Radiação , Espécies Reativas de Oxigênio/metabolismo
2.
Nat Commun ; 12(1): 90, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397943

RESUMO

Enterohemorrhagic Escherichia coli (EHEC) induces changes to the intestinal cell cytoskeleton and formation of attaching and effacing lesions, characterized by the effacement of microvilli and then formation of actin pedestals to which the bacteria are tightly attached. Here, we use a Caenorhabditis elegans model of EHEC infection to show that microvillar effacement is mediated by a signalling pathway including mitotic cyclin-dependent kinase 1 (CDK1) and diaphanous-related formin 1 (CYK1). Similar observations are also made using EHEC-infected human intestinal cells in vitro. Our results support the use of C. elegans as a host model for studying attaching and effacing lesions in vivo, and reveal that the CDK1-formin signal axis is necessary for EHEC-induced microvillar effacement.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ciclo Celular/metabolismo , Escherichia coli Êntero-Hemorrágica/fisiologia , Interações Hospedeiro-Patógeno , Microvilosidades/microbiologia , Microvilosidades/patologia , Actinas/metabolismo , Animais , Células CACO-2 , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/microbiologia , Caenorhabditis elegans/ultraestrutura , Carboidratos Epimerases/metabolismo , Escherichia coli Êntero-Hemorrágica/patogenicidade , Forminas , Humanos , Intestinos/microbiologia , Microvilosidades/metabolismo , Fosforilação , Fosfotreonina/metabolismo , Virulência
3.
Science ; 371(6524): 64-67, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33384372

RESUMO

During cell division, kinetochores couple chromosomes to spindle microtubules. To protect against chromosome gain or loss, kinetochores lacking microtubule attachment locally catalyze association of the checkpoint proteins Cdc20 and Mad2, which is the key event in the formation of a diffusible checkpoint complex that prevents mitotic exit. We elucidated the mechanism of kinetochore-catalyzed Mad2-Cdc20 assembly with a probe that specifically monitors this assembly reaction at kinetochores in living cells. We found that catalysis occurs through a tripartite mechanism that includes localized delivery of Mad2 and Cdc20 substrates and two phosphorylation-dependent interactions that geometrically constrain their positions and prime Cdc20 for interaction with Mad2. These results reveal how unattached kinetochores create a signal that ensures genome integrity during cell division.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas Cdc20/metabolismo , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Cinetocoros/metabolismo , Animais , Biocatálise , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Mitose , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
4.
Sci Total Environ ; 765: 144334, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33385812

RESUMO

Ionic liquids (ILs) become emerging pollutants and their toxicities earn increasing attentions. Yet, their effects were seldom explored on reproduction which connects generations and also effects across generations. In the present study, reproductive effects of 1-ethyl-3-methylimidazolium bromide ([C2mim]Br), one representative IL, were studied on C. elegans with 11 continuously exposed generations (F1 to F11). At 8.20E-5 g/L, the effects on the initial reproduction showed oscillatory changes between stimulation (in F1, F3, F4, F6 and F10) and inhibition (in F2, F5, F7, F8 and F11). At 8.20E-3 g/L, the effects on the reproduction over generations also showed such oscillation despite of different stimulation or inhibition levels, and even opposite influences in F4 and F11. The effects of [C2mim]Br on the total reproduction also showed the concentration-dependent oscillation between stimulation and inhibition over generations, though they had less alteration frequencies than those on the initial reproduction. Biochemical and molecular indicators were further measured in F1, F4, F7 and F11 to explore potential mechanisms. Results showed that the effects on spermatocyte protein 8 (SPE8) showed positive correlation with those on reproduction while the influences on major sperm protein (MSP) and sperm transmembrane protein 9 (SPE9) showed negative correlation with SPE8. Moreover, the dysregulation on expressions of acs-2 and akt-1 indicated the involvement of glucolipid metabolism. The changes in expressions of set-2, met-2, set-25 and mes-4 demonstrated that the long-term reproductive impacts of [C2mim]Br over generations also involved histone methylation at H3K4, H3K9 and H3K36, which also connected with the glucolipid metabolism.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Proteínas de Caenorhabditis elegans/genética , Características da Família , Imidazóis/toxicidade , Reprodução
5.
Science ; 371(6526)2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33446527

RESUMO

Multicellular organisms are composed of cells connected by ancestry and descent from progenitor cells. The dynamics of cell birth, death, and inheritance within an organism give rise to the fundamental processes of development, differentiation, and cancer. Technical advances in molecular biology now allow us to study cellular composition, ancestry, and evolution at the resolution of individual cells within an organism or tissue. Here, we take a phylogenetic and phylodynamic approach to single-cell biology. We explain how "tree thinking" is important to the interpretation of the growing body of cell-level data and how ecological null models can benefit statistical hypothesis testing. Experimental progress in cell biology should be accompanied by theoretical developments if we are to exploit fully the dynamical information in single-cell data.


Assuntos
Linhagem da Célula , Filogenia , Análise de Célula Única , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/crescimento & desenvolvimento , Biologia Celular/tendências , Humanos , Células-Tronco/citologia , Células-Tronco/fisiologia
6.
Food Chem ; 346: 128952, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33421900

RESUMO

Practical application of proanthocyanidins (PAs) as antioxidants is limited because of their hard-to-maintained activities during the processes and storage and in severe gastrointestinal environments. To overcome this challenge, we have developed an easy and green method to encapsulate PAs based on casein-maltodextrin Maillard conjugates. The current work entails the systematic study on the antioxidative potentials of fabricated casein-maltodextrin-PAs nanoparticles (CMPNs). In vitro antioxidant activities of CMPNs remained well during storage in 28 days and treatments under 40-80 °C. In vivo Caenorhabditis elegans (C. elegans) model further showed that the CMPNs could prolong the lifespan of nematodes and protected nematodes from oxidative stress and heat shock. Analyses of intracellular superoxide dismutase and catalase activities also confirmed the existence of an antioxidant protective effect. Besides, in vitro release test showed that the encapsulation enhanced the bioaccessibility of PAs. These results have important implications for the development of novel antioxidants in nutraceutical industries.


Assuntos
Antioxidantes/química , Caseínas/química , Polissacarídeos/química , Proantocianidinas/química , Animais , Antioxidantes/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/fisiologia , Catalase/metabolismo , Longevidade/efeitos dos fármacos , Reação de Maillard , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Proantocianidinas/farmacologia , Superóxido Dismutase/metabolismo
7.
Nat Commun ; 12(1): 49, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397961

RESUMO

Aging and fertility are two interconnected processes. From invertebrates to mammals, absence of the germline increases longevity. Here we show that loss of function of sul-2, the Caenorhabditis elegans steroid sulfatase (STS), raises the pool of sulfated steroid hormones, increases longevity and ameliorates protein aggregation diseases. This increased longevity requires factors involved in germline-mediated longevity (daf-16, daf-12, kri-1, tcer-1 and daf-36 genes) although sul-2 mutations do not affect fertility. Interestingly, sul-2 is only expressed in sensory neurons, suggesting a regulation of sulfated hormones state by environmental cues. Treatment with the specific STS inhibitor STX64, as well as with testosterone-derived sulfated hormones reproduces the longevity phenotype of sul-2 mutants. Remarkably, those treatments ameliorate protein aggregation diseases in C. elegans, and STX64 also Alzheimer's disease in a mammalian model. These results open the possibility of reallocating steroid sulfatase inhibitors or derivates for the treatment of aging and aging related diseases.


Assuntos
Doença de Alzheimer/enzimologia , Doença de Alzheimer/patologia , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/fisiologia , Longevidade , Esteril-Sulfatase/metabolismo , Sulfatases/metabolismo , Animais , Modelos Animais de Doenças , Epistasia Genética , Gônadas/metabolismo , Camundongos , Fenótipo , Células Receptoras Sensoriais/metabolismo , Esteroides/metabolismo
8.
Adv Exp Med Biol ; 1293: 321-334, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33398823

RESUMO

With a compact neural circuit consisting of entirely mapped 302 neurons, Caenorhabditis elegans plays an important role in the development and application of optogenetics. Optogenetics in C. elegans offers the opportunity that drastically changes experimental designs with increasing accessibility for neural activity and various cellular processes, thereby accelerating the studies on the functions of neural circuits and multicellular systems. Combining optogenetics with other approaches such as electrophysiology increases the resolution of elucidation. In particular, technologies like patterned illumination specifically developed in combination with optogenetics provide new tools to interrogate neural functions. In this chapter, we introduce the reasons to use optogenetics in C. elegans, and discuss the technical issues raised, especially for C. elegans by revisiting our chapter in the first edition of this book. Throughout the chapter, we review early and recent milestone works using optogenetics to investigate a variety of biological systems including neural and behavioral regulation.


Assuntos
Caenorhabditis elegans , Optogenética/métodos , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Neurônios/metabolismo
9.
Nat Commun ; 12(1): 476, 2021 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-33473107

RESUMO

Endonuclease G (ENDOG), a mitochondrial nuclease, is known to participate in many cellular processes, including apoptosis and paternal mitochondrial elimination, while its role in autophagy remains unclear. Here, we report that ENDOG released from mitochondria promotes autophagy during starvation, which we find to be evolutionally conserved across species by performing experiments in human cell lines, mice, Drosophila and C. elegans. Under starvation, Glycogen synthase kinase 3 beta-mediated phosphorylation of ENDOG at Thr-128 and Ser-288 enhances its interaction with 14-3-3γ, which leads to the release of Tuberin (TSC2) and Phosphatidylinositol 3-kinase catalytic subunit type 3 (Vps34) from 14-3-3γ, followed by mTOR pathway suppression and autophagy initiation. Alternatively, ENDOG activates DNA damage response and triggers autophagy through its endonuclease activity. Our results demonstrate that ENDOG is a crucial regulator of autophagy, manifested by phosphorylation-mediated interaction with 14-3-3γ, and its endonuclease activity-mediated DNA damage response.


Assuntos
Autofagia/fisiologia , Dano ao DNA/fisiologia , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Proteínas 14-3-3/metabolismo , Animais , Apoptose , Caenorhabditis elegans , Linhagem Celular , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Drosophila , Técnicas de Inativação de Genes , Células Hep G2 , Humanos , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Fosforilação , Transcriptoma , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo
10.
Nat Commun ; 12(1): 479, 2021 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-33473112

RESUMO

As organisms develop, individual cells generate mitochondria to fulfill physiological requirements. However, it remains unknown how mitochondrial network expansion is scaled to cell growth. The mitochondrial unfolded protein response (UPRmt) is a signaling pathway mediated by the transcription factor ATFS-1 which harbors a mitochondrial targeting sequence (MTS). Here, using the model organism Caenorhabditis elegans we demonstrate that ATFS-1 mediates an adaptable mitochondrial network expansion program that is active throughout normal development. Mitochondrial network expansion requires the relatively inefficient MTS in ATFS-1, which allows the transcription factor to be responsive to parameters that impact protein import capacity of the mitochondrial network. Increasing the strength of the ATFS-1 MTS impairs UPRmt activity by increasing accumulation within mitochondria. Manipulations of TORC1 activity increase or decrease ATFS-1 activity in a manner that correlates with protein synthesis. Lastly, expression of mitochondrial-targeted GFP is sufficient to expand the muscle cell mitochondrial network in an ATFS-1-dependent manner. We propose that mitochondrial network expansion during development is an emergent property of the synthesis of highly expressed mitochondrial proteins that exclude ATFS-1 from mitochondrial import, causing UPRmt activation.


Assuntos
Proteínas de Caenorhabditis elegans/biossíntese , Caenorhabditis elegans/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Biossíntese de Proteínas/fisiologia , Animais , Caenorhabditis elegans/genética , Metabolismo Energético , Regulação da Expressão Gênica , Chaperonas Moleculares , Transporte Proteico , Transdução de Sinais , Fatores de Transcrição/metabolismo , Resposta a Proteínas não Dobradas
11.
J Ethnopharmacol ; 266: 113418, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32991971

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Danshen, is a traditional Chinese medicine obtained from the dried root and rhizome of Salvia miltiorrhiza Bunge. It is known to be used for neurological disorder including for Alzheimer's disease (AD). This study uncovers the effect of Danshen water extract on the Alzheimer's disease model of C.elegans. MATERIAL AND METHODS: The composition of Danshen water extract was determined using (High Performance Liquid Chromatography (HPLC). Then Thioflavin T assay was used to determined if Danshen water extract could prevent the aggregation of amyloid-ß peptide (Aß). Alzheimer's disease C.elegans model was used to determine the effect of Danshen water extract. Finally, the reactive oxygen species (ROS) was determined using the 2,7-dichlorofuorescein diacetate method. RESULTS: In this study, we found that standardized Danshen water extract that contains danshensu (1.26%), salvianolic acid A (0.35%) and salvianolic acid B (2.21%) are able to bind directly to Aß and prevents it from aggregating. The IC50 for the inhibition of Aß aggregation by Danshen water extract was 0.5 mg/ml. In the AD model of C.elegans, Danshen water extract managed to alleviates the paralysis phenotype. Furthermore, the administration of Danshen water extract displayed antioxidant properties toward the Aß-induced oxidative stress. CONCLUSIONS: AD is a widespread neurodegenerative disease attributed to the accumulation of extracellular plaques comprising Aß. Danshen water extract could significantly reduce the progress of paralysis in the AD model of C. elegans, showing promising results with its antioxidant properties. It can be concluded that Danshen water extract could potentially serve as a therapeutic for AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Antioxidantes/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Fármacos Neuroprotetores/farmacologia , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Caenorhabditis elegans/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/isolamento & purificação , Estresse Oxidativo/efeitos dos fármacos , Placa Amiloide/metabolismo , Espécies Reativas de Oxigênio/metabolismo
12.
Food Chem ; 339: 127813, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916401

RESUMO

Bisphenol S (BPS), a structural analog of Bisphenol A (BPA), has been widely used as a substitute for epoxy resin, food packaging materials, and other products due to the limited application of BPA. Studies in vivo and in vitro have indicated that BPA could induce fat accumulation like an obesogen. The main goal of this study was to investigate the role and mechanism of BPS in lipid metabolism using Caenorhabditis elegans (C. elegans) as a model. Results showed that both the overall fat deposition and the triglyceride level were significantly increased in a non-monotonically increasing trend, and the low dose of BPS (0.01 µM) exhibited a stronger influence. Additionally, BPS enhanced fat synthesis depending on daf-16, fat-5, fat-6 and fat-7, and inhibited fatty acid oxidation via nhr-49 and acs-2. This study further indicate that fat accumulation induced by BPS requires nhr-49, which also mediated the nuclear hormone signaling pathway.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Glucose/efeitos adversos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fenóis/toxicidade , Sulfonas/toxicidade , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Dieta/efeitos adversos , Gorduras/metabolismo , Ácidos Graxos/metabolismo , Glucose/administração & dosagem , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Triglicerídeos/metabolismo
13.
Chem Biol Interact ; 334: 109363, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33358771

RESUMO

The effect of the presence of food on the incorporation and excretion of silica particles was studied in this work using the biological model Caenorhabditis elegans and image analysis techniques. The experiment was based on two 24-hour phases: exposure and depuration. During exposure, nematodes were maintained for 24 h in liquid medium with silica particles, but some with and others without food. During depuration, nematodes were transferred to medium without particles. Nematodes were analysed by an image analysis in both phases to quantify the properties of particle distributions in nematodes' bodies with time. No differences were found in the proportion of nematodes carrying particles in the exposure phase when food was present. However in the depuration phase, lack of food generated a high proportion of particle carriers. Particle distribution properties were also similar in the exposure phase. Nevertheless, lack of food produced particle accumulation due to decelerated excretion because digestive tube relaxed under these conditions. Thus after the depuration phase, lack of food led particles to persist in digestive tubes. According to these results, intake of silica particles had no retention effects when a food flux was provided, but particles were not easily excreted when the food flux was interrupted.


Assuntos
Caenorhabditis elegans/metabolismo , Ingestão de Alimentos/fisiologia , Dióxido de Silício/metabolismo , Animais , Alimentos , Cinética
14.
Food Chem ; 339: 127879, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877814

RESUMO

Qualitative analysis of bound polyphenols from carrot dietary fiber (CDF-PP) was performed by ultra-performance liquid chromatography equipped with an electrospray ionization and quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS/MS). Eleven organic acids, nine hydroxybenzoic acids and derivatives, six hydroxycinnamic acids and derivatives, four phenolic alcohols and derivatives, three flavonoids and derivatives, seven esters and derivatives, two other compounds, were detected by matching their retention times, secondary mass spectrometry fragment information with authentic standards or literature data. Furthermore, in vitro antioxidant activity was determined by different kinds of assays, including DPPH, ORAC, PSC, demonstrated that CDF-PP could scavenge radicals in a dose dependent manner. Moreover, CDF-PP exhibited significantly reactive oxygen species (ROS) scavenging activity in living Caenorhabditis elegans. To our knowledge, this is the first comprehensive research to investigate composition and in vitro/in vivo antioxidant activity of bound polyphenols in CDF, which implied that CDF-PP could be a promising source of antioxidants.


Assuntos
Antioxidantes/química , Daucus carota/química , Fibras na Dieta/análise , Polifenóis/análise , Animais , Antioxidantes/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/metabolismo , Cromatografia Líquida de Alta Pressão , Daucus carota/metabolismo , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologia , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Massas em Tandem
15.
Phytomedicine ; 81: 153439, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33352493

RESUMO

BACKGROUND: Depression and stress-related disorders are leading causes of death worldwide. Standard treatments elevating serotonin or noradrenaline levels are not sufficiently effective and cause adverse side effects. A connection between dopamine pathways and stress-related disorders has been suggested. Compounds derived from herbal medicine could be a promising alternative. We examined the neuroprotective effects of ursolic acid (UA) by focusing on dopamine signalling. METHODS: Trolox equivalent capacity assay was used to determine the antioxidant activities of UA in vitro. C. elegans N2 wildtype and dopamine receptor-knockout mutants (dop1-deficient RB665 and dop3-deficient LX703 strains) were used as in vivo models. H2DCFDA and acute juglone assays were applied to determine the antioxidant activity in dependency of dopamine pathways in vivo. Stress was assessed by heat and acute osmotic stress assays. The influence of UA on overall survival was analyzed by a life span assay. The dop1 and dop3 mRNA expression was determined by real time RT-PCR. We also examined the binding affinity of UA towards C. elegans Dop1 and Dop3 receptors as well as human dopamine receptors D1 and D3 by molecular docking. RESULTS: Antioxidant activity assays showed that UA exerts strong antioxidant activity. UA increased resistance towards oxidative, osmotic and heat stress. Additionally, UA increased life span of nematodes. Moreover, dop1 and dop3 gene expression was significantly enhanced upon UA treatment. Docking analysis revealed stronger binding affinity of UA to C. elegans and human dopamine receptors than the natural ligand, dopamine. Binding to Dop1 was stronger than to Dop3. CONCLUSION: UA reduced stress-dependent ROS generation and acted through Dop1 and to a lesser extent through Dop3 to reduce stress and prolong life span in C. elegans. These results indicate that UA could be a promising lead compound for the development of new antidepressant medications.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/efeitos dos fármacos , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Estresse Fisiológico/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Antioxidantes/farmacologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/metabolismo , Dopamina/metabolismo , Técnicas de Inativação de Genes , Humanos , Longevidade/efeitos dos fármacos , Simulação de Acoplamento Molecular , Mutação , Espécies Reativas de Oxigênio/metabolismo , Receptores de Dopamina D1/química , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/química , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D3/química , Receptores de Dopamina D3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/genética , Triterpenos/química
16.
Mol Cell ; 81(3): 546-557.e5, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33378643

RESUMO

Eukaryotic cells regulate 5'-triphosphorylated RNAs (ppp-RNAs) to promote cellular functions and prevent recognition by antiviral RNA sensors. For example, RNA capping enzymes possess triphosphatase domains that remove the γ phosphates of ppp-RNAs during RNA capping. Members of the closely related PIR-1 (phosphatase that interacts with RNA and ribonucleoprotein particle 1) family of RNA polyphosphatases remove both the ß and γ phosphates from ppp-RNAs. Here, we show that C. elegans PIR-1 dephosphorylates ppp-RNAs made by cellular RNA-dependent RNA polymerases (RdRPs) and is required for the maturation of 26G-RNAs, Dicer-dependent small RNAs that regulate thousands of genes during spermatogenesis and embryogenesis. PIR-1 also regulates the CSR-1 22G-RNA pathway and has critical functions in both somatic and germline development. Our findings suggest that PIR-1 modulates both Dicer-dependent and Dicer-independent Argonaute pathways and provide insight into how cells and viruses use a conserved RNA phosphatase to regulate and respond to ppp-RNA species.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Monoéster Fosfórico Hidrolases/metabolismo , Processamento Pós-Transcricional do RNA , RNA/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Regulação da Expressão Gênica no Desenvolvimento , Monoéster Fosfórico Hidrolases/genética , Fosforilação , RNA/genética , Capuzes de RNA , /metabolismo , Ribonuclease III/genética , Ribonuclease III/metabolismo , Espermatogênese , Especificidade por Substrato
17.
Anal Chem ; 93(3): 1369-1376, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33355449

RESUMO

Recent development in fluorescence-based molecular tools has contributed significantly to developmental studies, including embryogenesis. Many of these tools rely on multiple steps of sample manipulation, so obtaining large sample sizes presents a major challenge as it can be labor-intensive and time-consuming. However, large sample sizes are required to uncover critical aspects of embryogenesis, for example, subtle phenotypic differences or gene expression dynamics. This problem is particularly relevant for single-molecule fluorescence in situ hybridization (smFISH) studies in Caenorhabditis elegans embryogenesis. Microfluidics can help address this issue by allowing a large number of samples and parallelization of experiments. However, performing efficient reagent exchange on chip for large numbers of embryos remains a bottleneck. Here, we present a microfluidic pipeline for large-scale smFISH imaging of C. elegans embryos with minimized labor. We designed embryo traps and engineered a protocol allowing for efficient chemical exchange for hundreds of C. elegans embryos simultaneously. Furthermore, the device design and small footprint optimize imaging throughput by facilitating spatial registration and enabling minimal user input. We conducted the smFISH protocol on chip and demonstrated that image quality is preserved. With one device replacing the equivalent of 10 glass slides of embryos mounted manually, our microfluidic approach greatly increases throughput. Finally, to highlight the capability of our platform to perform longitudinal studies with high temporal resolution, we conducted a temporal analysis of par-1 gene expression in early C. elegans embryos. The method demonstrated here paves the way for systematic high-temporal-resolution studies that will benefit large-scale RNAi and drug screens and in systems beyond C. elegans embryos.


Assuntos
Caenorhabditis elegans/genética , Desenvolvimento Embrionário/genética , Hibridização in Situ Fluorescente , Animais , Caenorhabditis elegans/embriologia , Embrião não Mamífero
18.
Am J Hum Genet ; 108(1): 134-147, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33340455

RESUMO

The ubiquitin-proteasome system facilitates the degradation of unstable or damaged proteins. UBR1-7, which are members of hundreds of E3 ubiquitin ligases, recognize and regulate the half-life of specific proteins on the basis of their N-terminal sequences ("N-end rule"). In seven individuals with intellectual disability, epilepsy, ptosis, hypothyroidism, and genital anomalies, we uncovered bi-allelic variants in UBR7. Their phenotype differs significantly from that of Johanson-Blizzard syndrome (JBS), which is caused by bi-allelic variants in UBR1, notably by the presence of epilepsy and the absence of exocrine pancreatic insufficiency and hypoplasia of nasal alae. While the mechanistic etiology of JBS remains uncertain, mutation of both Ubr1 and Ubr2 in the mouse or of the C. elegans UBR5 ortholog results in Notch signaling defects. Consistent with a potential role in Notch signaling, C. elegans ubr-7 expression partially overlaps with that of ubr-5, including in neurons, as well as the distal tip cell that plays a crucial role in signaling to germline stem cells via the Notch signaling pathway. Analysis of ubr-5 and ubr-7 single mutants and double mutants revealed genetic interactions with the Notch receptor gene glp-1 that influenced development and embryo formation. Collectively, our findings further implicate the UBR protein family and the Notch signaling pathway in a neurodevelopmental syndrome with epilepsy, ptosis, and hypothyroidism that differs from JBS. Further studies exploring a potential role in histone regulation are warranted given clinical overlap with KAT6B disorders and the interaction of UBR7 and UBR5 with histones.


Assuntos
Epilepsia/genética , Hipotireoidismo/genética , Transtornos do Neurodesenvolvimento/genética , Receptores Notch/genética , Transdução de Sinais/genética , Ubiquitina-Proteína Ligases/genética , Animais , Anus Imperfurado/genética , Caenorhabditis elegans/genética , Linhagem Celular , Displasia Ectodérmica/genética , Transtornos do Crescimento/genética , Células HEK293 , Perda Auditiva Neurossensorial/genética , Histonas/genética , Humanos , Deficiência Intelectual/genética , Camundongos , Mutação/genética , Nariz/anormalidades , Pancreatopatias/genética , Complexo de Endopeptidases do Proteassoma/genética
19.
Environ Pollut ; 271: 116337, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33383415

RESUMO

Microplastics pollution is a serious ecological threat, severely affecting environments and human health. Tackling microplastics pollution requires an effective methodology to detect minute polymer particles in environmental samples and organisms. Here were report a novel methodology to visualise and identify nanoscale (down to 100 nm) and microscale synthetic commercially-available uniform spherical polymer particles using dark-field hyperspectral microscopy in visible-near infrared (400-1000 nm) wavelength range. Polystyrene particles with diameters between 100 nm-1 µm, polymethacrylate 1 µm and melamine formaldehyde 2 µm microspheres suspended in pure water samples were effectively imaged and chemically identified based on spectral signatures and image-assisted analysis. We succeeded in visualisation and spectral identification of pure and mixed nano- and microplastics in vivo employing optically-transparent Caenorhabditis elegans nematodes as a model to demonstrate the ingestion and tissue distribution of microplastics. As we demonstrate here, dark-field hyperspectral microscopy is capable for differentiating between chemically-different microplastics confined within live invertebrate intestines. Moreover, this optical technology allows for quantitative identification of microplastics ingested by nematodes. We believe that this label-free non-destructive methodology will find numerous applications in environmental nano- and microplastics detection and quantification, investigation of their biodistribution in tissues and organs and nanotoxicology.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Caenorhabditis elegans , Monitoramento Ambiental , Humanos , Microscopia , Plásticos , Distribuição Tecidual , Poluentes Químicos da Água/análise
20.
Environ Pollut ; 271: 116335, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33383418

RESUMO

The surface modifications of nanoparticles (NPs), are well-recognized parameters that affect the toxicity, while there has no study on toxicity of Al2O3 NPs with different surface modification. Therefore, for the first time, this study pays attention to evaluating the toxicity and potential mechanism of pristine Al2O3 NPs (p-Al2O3), hydrophilic (w-Al2O3) and lipophilic (o-Al2O3) modifications of Al2O3 NPs both in vitro and in vivo. Applied concentrations of 10, 20, 40, 80,100 and 200 µg/mL for 24 h exposure on Caenorhabditis elegans (C. elegans), while 100 µg/mL of Al2O3 NPs significantly decreased the survival rate. Using multiple toxicological endpoints, we found that o-Al2O3 NPs (100 µg/mL) could induce more severe toxicity than p-Al2O3 and w-Al2O3 NPs. After uptake by C. elegans, o-Al2O3 NPs increased the intestinal permeability, easily swallow and further destroy the intestinal membrane cells. Besides, cytotoxicity evaluation revealed that o-Al2O3 NPs (100 µg/mL) are more toxic than p-Al2O3 and w-Al2O3. Once inside the cell, o-Al2O3 NPs could attack mitochondria and induce the over-production of reactive oxygen species (ROS), which destroy the intracellular redox balance and lead to apoptosis. Furthermore, the transcriptome sequencing and RT-qPCR data also demonstrated that the toxicity of o-Al2O3 NPs is highly related to the damage of cell membrane and the imbalance of intracellular redox. Generally, our study has offered a comprehensive sight to the adverse effects of different surface modifications of Al2O3 NPs on environmental organisms and the possible underlying mechanisms.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Óxido de Alumínio/toxicidade , Animais , Apoptose , Caenorhabditis elegans , Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Estresse Oxidativo , Espécies Reativas de Oxigênio
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