scholarly journals Eicosanoid formation by a cytochrome P450 isoform expressed in the pharynx of Caenorhabditis elegans

2011 ◽  
Vol 435 (3) ◽  
pp. 689-700 ◽  
Author(s):  
Mandy Kosel ◽  
Waltraud Wild ◽  
Alexandra Bell ◽  
Michael Rothe ◽  
Carsten Lindschau ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Caenorhabditis Elegans ◽  
C Elegans ◽  
Gfp Reporter ◽  
Cytochrome P450 Genes ◽  
Acid Metabolites ◽  
Pharyngeal Pumping ◽  
Cyp Isoforms ◽  
Marginal Cells ◽  
Eicosanoid Formation

Caenorhabditis elegans harbours several CYP (cytochrome P450) genes that are homologous with mammalian CYP isoforms important to the production of physiologically active AA (arachidonic acid) metabolites. We tested the hypothesis that mammals and C. elegans may share similar basic mechanisms of CYP-dependent eicosanoid formation and action. We focused on CYP33E2, an isoform related to the human AA-epoxygenases CYP2C8 and CYP2J2. Co-expression of CYP33E2 with the human NADPH–CYP reductase in insect cells resulted in the reconstitution of an active microsomal mono-oxygenase system that metabolized EPA (eicosapentaenoic acid) and, with lower activity, also AA to specific sets of regioisomeric epoxy- and hydroxy-derivatives. The main products included 17,18-epoxyeicosatetraenoic acid from EPA and 19-hydroxyeicosatetraenoic acid from AA. Using nematode worms carrying a pCYP33E2::GFP reporter construct, we found that CYP33E2 is exclusively expressed in the pharynx, where it is predominantly localized in the marginal cells. RNAi (RNA interference)-mediated CYP33E2 expression silencing as well as treatments with inhibitors of mammalian AA-metabolizing CYP enzymes, significantly reduced the pharyngeal pumping frequency of adult C. elegans. These results demonstrate that EPA and AA are efficient CYP33E2 substrates and suggest that CYP–eicosanoids, influencing in mammals the contractility of cardiomyocytes and vascular smooth muscle cells, may function in C. elegans as regulators of the pharyngeal pumping activity.

Creation of Low-Copy Integrated Transgenic Lines in Caenorhabditis elegans

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1217-1226 ◽  
Author(s):  
Vida Praitis ◽  
Elizabeth Casey ◽  
David Collar ◽  
Judith Austin
Keyword(s):  
Caenorhabditis Elegans ◽  
Expression Level ◽  
Dna Arrays ◽  
Extrachromosomal Dna ◽  
C Elegans ◽  
Microparticle Bombardment ◽  
Alternative Method ◽  
Extrachromosomal Array ◽  
Gfp Reporter ◽  
Transgenic Lines

Abstract In Caenorhabditis elegans, transgenic lines are typically created by injecting DNA into the hermaphrodite germline to form multicopy extrachromosomal DNA arrays. This technique is a reliable means of expressing transgenes in C. elegans, but its use has limitations. Because extrachromosomal arrays are semistable, only a fraction of the animals in a transgenic extrachromosomal array line are transformed. In addition, because extrachromosomal arrays can contain hundreds of copies of the transforming DNA, transgenes may be overexpressed, misexpressed, or silenced. We have developed an alternative method for C. elegans transformation, using microparticle bombardment, that produces single- and low-copy chromosomal insertions. Using this method, we find that it is possible to create integrated transgenic lines that reproducibly express GFP reporter constructs without the variations in expression level and pattern frequently exhibited by extrachromosomal array lines. In addition, we find that low-copy integrated lines can also be used to express transgenes in the C. elegans germline, where conventional extrachromosomal arrays typically fail to express due to germline silencing.

scholarly journals ATM Induces Cell Death with Autophagy in Response to H2O2 Specifically in Caenorhabditis elegans Nondividing Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Takahito Moriwaki ◽  
Akira Yamasaki ◽  
Qiu-Mei Zhang-Akiyama
Keyword(s):  
Cell Death ◽  
Caenorhabditis Elegans ◽  
Somatic Cells ◽  
Dead Cell ◽  
C Elegans ◽  
Cell Staining ◽  
Dna Damaging Agents ◽  
Gfp Reporter ◽  
Wide Range ◽  
Reporter Assays

Introduction. Ataxia-telangiectasia-mutated (ATM) kinase is a master regulator of the DNA damage response and is directly activated by reactive oxygen species (ROSs) in addition to DNA double-stranded breaks. However, the physiological function of the response to ROSs is not understood. Purpose. In the present study, we investigated how ATM responds to ROSs in Caenorhabditis elegans (C. elegans). Materials and Methods. First, we measured sensitivities of larvae to DNA-damaging agents and ROSs. Next, we analyzed the drug sensitivities of fully matured adult worms, which consist of nondividing somatic cells. Dead cell staining with acridine orange was performed to visualize the dead cells. In addition, we performed GFP reporter assays of lgg-1, an autophagy-related gene, to determine the types of cell death. Results. atm-1(tm5027) larvae showed a wide range of sensitivities to both DNA-damaging agents and ROSs. In contrast, fully matured adult worms, which consist of nondividing somatic cells, showed sensitivity to DNA-damaging agent, NaHSO3, but they showed resistance to H2O2. Dead cell staining and GFP reporter assays of lgg-1 suggest that C. elegans ATM-1 induces the cell death with autophagy in intestinal cells in response to H2O2. Conclusion. We revealed that ATM induces cell death in response to H2O2.

scholarly journals A scalable method for automatically measuring pharyngeal pumping in C. elegans

2016 ◽  
Author(s):  
Monika Scholz ◽  
Dylan J. Lynch ◽  
Kyung Suk Lee ◽  
Erel Levine ◽  
David Biron
Keyword(s):  
Caenorhabditis Elegans ◽  
Food Availability ◽  
High Throughput ◽  
Visual Inspection ◽  
Automated Analysis ◽  
C Elegans ◽  
Automated Method ◽  
Controlled Environments ◽  
Pharyngeal Pumping ◽  
Feeding Environments

We describe a scalable automated method for measuring the pharyngeal pumping of Caenorhabditis elegans in controlled environments. Our approach enables unbiased measurements for prolonged periods, a high throughput, and measurements in controlled yet dynamically changing feeding environments. The automated analysis compares well with scoring pumping by visual inspection, a common practice in the field. In addition, we observed overall low rates of pharyngeal pumping and long correlation times when food availability was oscillated.

scholarly journals Enhanced Healthspan in Caenorhabditis elegans Treated With Extracts From the Traditional Chinese Medicine Plants Cuscuta chinensis Lam. and Eucommia ulmoides Oliv.

2021 ◽  
Vol 12 ◽  
Author(s):  
Shimaa M. A. Sayed ◽  
Karsten Siems ◽  
Christian Schmitz-Linneweber ◽  
Walter Luyten ◽  
Nadine Saul
Keyword(s):  
Caenorhabditis Elegans ◽  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Eucommia Ulmoides ◽  
Pumping Rate ◽  
C Elegans ◽  
Beneficial Effects ◽  
Physiological Fitness ◽  
Pharyngeal Pumping ◽  
Cuscuta Chinensis

To uncover potential anti-aging capacities of Traditional Chinese Medicine (TCM), the nematode Caenorhabditis elegans was used to investigate the effects of Eucommia ulmoides and Cuscuta chinensis extracts, selected by screening seven TCM extracts, on different healthspan parameters. Nematodes exposed to E. ulmoides and C. chinensis extracts, starting at the young adult stage, exhibited prolonged lifespan and increased survival after heat stress as well as upon exposure to the pathogenic bacterium Photorhabdus luminescens, whereby the survival benefits were monitored after stress initiation at different adult stages. However, only C. chinensis had the ability to enhance physical fitness: the swimming behavior and the pharyngeal pumping rate of C. elegans were improved at day 7 and especially at day 12 of adulthood. Finally, monitoring the red fluorescence of aged worms revealed that only C. chinensis extracts caused suppression of intestinal autofluorescence, a known marker of aging. The results underline the different modes of action of the tested plants extracts. E. ulmoides improved specifically the physiological fitness by increasing the survival probability of C. elegans after stress, while C. chinensis seems to be an overall healthspan enhancer, reflected in the suppressed autofluorescence, with beneficial effects on physical as well as physiological fitness. The C. chinensis effects may be hormetic: this is supported by increased gene expression of hsp-16.1 and by trend, also of hsp-12.6.

scholarly journals Some Phenotypic Characteristics of Nematode Caenorhabditis elegans Strains with Defective Functions of the Sestrin (cSesn) gene

2018 ◽  
Vol 11 (2) ◽  
pp. 759-767 ◽  
Author(s):  
A. O. Zeltukhin ◽  
G. V. Ilyinskaya ◽  
A. V. Budanov ◽  
P. M. Chumakov
Keyword(s):  
Caenorhabditis Elegans ◽  
Redox Homeostasis ◽  
Functional Decline ◽  
Extended Period ◽  
Locomotory Activity ◽  
Pumping Rate ◽  
Phenotypic Differences ◽  
C Elegans ◽  
Age Related ◽  
Pharyngeal Pumping

In mammals a small family of genes called Sestrins play important roles in the maintenance of metabolic and redox homeostasis, suggesting that the genes may positively affect the lifespan and counteract the age-related functional decline. The nematode genome contains a single cSesn gene that makes the Caenorhabditis elegans an excellent model for studying functions of the sestrin family. We describe phenotypic differences of worms that have compromised expression of cSesn gene. By comparing three different cSesn-deficient modes with the wild-type C. elegans strain we show that the abrogation of cSesn expression results in an increased body size, an extended period of body growth, a reduces brood size and number of offspring per a single worm, an accelerated decline in muscular functions revealed as a rapid decrease in the pharyngeal pumping rate and in the overall locomotory activity. The results are consistent with the potential roles of cSesn in counteracting the process of aging in C. elegans.

scholarly journals The Marginal Cells of the Caenorhabditis elegans Pharynx Scavenge Cholesterol and Other Hydrophobic Small Molecules

2019 ◽  
Author(s):  
Muntasir Kamal ◽  
Houtan Moshiri ◽  
Lilia Magomedova ◽  
Duhyun Han ◽  
Ken CQ Nguyen ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Small Molecules ◽  
Plasma Membranes ◽  
Bacterial Suspension ◽  
Filter Feeder ◽  
C Elegans ◽  
Sphingomyelin Synthase ◽  
Outer Leaflet ◽  
Marginal Cells

AbstractThe nematode worm Caenorhabditis elegans is a bacterivore filter feeder. Through the contraction of the worm’s pharynx, a bacterial suspension is sucked into the pharynx’s lumen. Excess liquid is then shunted out of the buccal cavity through ancillary channels that are made from specialized pharyngeal cells called marginal cells. Through the characterization of our library of worm-bioactive small molecules (a.k.a. wactives), we found that more than one third of wactives visibly accumulate inside of the marginal cells as crystals or globular spheres. Wactives that visibly accumulate are typically more hydrophobic than those that do not. To understand why wactives accumulate specifically in marginal cells, we performed a forward genetic screen for mutants that resist the lethality associated with one crystallizing wactive. We identified a presumptive sphingomyelin-synthesis pathway that is necessary for crystal and sphere accumulation. Sphingomyelin is a phospholipid that is enriched in the outer leaflet of the plasma membranes of most metazoans. We find that the predicted terminal enzyme of this pathway, sphingomyelin synthase 5 (SMS-5), is expressed in the pharynx, contributes to sphingomyelin abundance, and that its expression in marginal cells is sufficient for wactive accumulation. We also find that the expression of SMS-5 in the marginal cells is necessary for the proper absorption of exogenous cholesterol, without which C. elegans cannot develop. We conclude that the sphingomyelin-rich plasma membrane of the marginal cells acts as a sink to scavenge important hydrophobic nutrients from the filtered liquid that might otherwise be shunted back into the environment.One sentence summaryThe anterior pharynx of C. elegans is a Sink for Hydrophobic Small Molecules

scholarly journals Aqueous Bark Extract of Ceiba speciosa (A. St.-Hill) Ravenna Protects against Glucose Toxicity in Caenorhabditis elegans

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Fabrine Bianchin dos Santos ◽  
Caroline Brandão Quines ◽  
Luiz Eduardo Ben Pilissão ◽  
Ana Helena de Castro Dal Forno ◽  
Cristiane Freitas Rodrigues ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Lipid Accumulation ◽  
Biological Activities ◽  
Folk Medicine ◽  
Stem Bark ◽  
Bark Extract ◽  
C Elegans ◽  
Glucose Levels ◽  
Exogenous Glucose ◽  
Pharyngeal Pumping

Plants are widely used in folk medicine because of their pharmacological properties. Ceiba speciosa, popularly known as paineira-rosa or tree-of-wool, is a species found in the Northwest of Rio Grande do Sul, being native of the upper Uruguay River, Brazil. The tea obtained from the stem bark is employed in folk medicine to reduce cholesterol, triacylglycerides, and glucose levels. However, there are no studies in the literature proving its efficacy or the safety of its use. For this study, we used Caenorhabditis elegans as an animal model considering its advantages for risk assessment and pharmacological screenings. For the toxicological tests, C. elegans N2 (wild type) was treated with the aqueous extract of the stem bark of C. speciosa (ECE) at the first larval stage (L1) at concentrations of 5, 25, 50, and 250 μg/mL. To evaluate biological activities, we challenged the extract for oxidative stress resistance in the presence of paraquat (0.5 mM), H2O2 (1 mM), and against glucose-induced toxicity. Our results demonstrated that ECE did not alter survival rate, pharyngeal pumping, and reproduction of the nematodes. The extract was not able to protect the nematodes against the toxicity induced by prooxidants. Notably, ECE protected against glucotoxicity by increasing worms’ life span and by reducing glucose levels. On the other hand, ECE treatment did not reduce lipid accumulation induced by exogenous glucose feeding, as observed in worms which lipid droplets were tagged with GFP. Based on our results, we believe that the extract is indeed promising for further studies focusing on carbohydrates metabolism; however, it needs to be carefully evaluated since the extract does not seem to modulate lipid accumulation.

scholarly journals Lifespan Extending and Oxidative Stress Resistance Properties of a Leaf Extracts from Anacardium occidentale L. in Caenorhabditis elegans

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Chatrawee Duangjan ◽  
Panthakarn Rangsinth ◽  
Xiaojie Gu ◽  
Michael Wink ◽  
Tewin Tencomnao
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Stress Resistance ◽  
Anacardium Occidentale ◽  
Leaf Extracts ◽  
Oxidative Stress Resistance ◽  
C Elegans ◽  
Pharyngeal Pumping ◽  
Antioxidative Stress ◽  
Underlying Mechanisms

Anacardium occidentale (AO) contains a number of polyphenolic secondary metabolites with antioxidant activity. The objectives of this study were aimed at investigating the roles of AO leaf extracts in antioxidative stress and longevity, as well as their underlying mechanisms, in the Caenorhabditis elegans (C. elegans) model. AO extracts mediated the survival rate of nematodes under oxidative stress by attenuating intracellular reactive oxygen species (ROS) via the DAF-16/FoxO and SKN-1/Nrf-2 signaling pathways. AO extracts stimulated the expression of stress response genes including SOD-3 and GST-4. Moreover, AO extracts exhibited antiaging activities and enhanced longevity. We observed improved pharyngeal pumping function, attenuation of pigment accumulation (lipofuscin), and an increased lifespan of the worms. Collectively, our results demonstrated that AO extracts exerted both oxidative stress resistance and antiaging properties in the C. elegans model and may lead to new agents to benefit humans in the near future.

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