Exploring Target Genes Involved in the Effect of Quercetin on the Response to Oxidative Stress in Caenorhabditis elegans

Quercetin is one the most abundant flavonoids in the human diet. Although it is well known that quercetin exhibits a range of biological activities, the mechanisms behind these activities remain unresolved. The aim of this work is to progress in the knowledge of the molecular mechanisms involved in the biological effects of quercetin using Caenorhabditis elegans as a model organism. With this aim, the nematode has been used to explore the ability of this flavonoid to modulate the insulin/insulin-like growth factor 1(IGF-1) signaling pathway (IIS) and the expression of some genes related to stress response. Different methodological approaches have been used, i.e., assays in knockout mutant worms, gene expression assessment by RT-qPCR, and C. elegans transgenic strains expressing green fluorescent protein (GFP) reporters. The results showed that the improvement of the oxidative stress resistance of C. elegans induced by quercetin could be explained, at least in part, by the modulation of the insulin signaling pathway, involving genes age-1, akt-1, akt-2, daf-18, sgk-1, daf-2, and skn-1. However, this effect could be independent of the transcription factors DAF-16 and HSF-1 that regulate this pathway. Moreover, quercetin was also able to increase expression of hsp-16.2 in aged worms. This observation could be of particular interest to explain the effects of enhanced lifespan and greater resistance to stress induced by quercetin in C. elegans, since the expression of many heat shock proteins diminishes in aging worms.

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Lipopolysaccharide exposure induces oxidative damage in Caenorhabditis elegans: protective effects of carnosine

BMC Pharmacology and Toxicology ◽

10.1186/s40360-020-00455-w ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Jing Ma ◽

Xiaoyuan Xu ◽

Ranran Wang ◽

Haijing Yan ◽

Huijuan Yao ◽

...

Keyword(s):

Oxidative Stress ◽

Caenorhabditis Elegans ◽

Signaling Pathway ◽

P38 Mapk ◽

Mapk Signaling ◽

Protective Effects ◽

Related Gene ◽

Rt Pcr ◽

C Elegans ◽

Apoptosis Related Gene

Abstract Background The present study was designed to investigate the protective effects and mechanisms of carnosine on lipopolysaccharide (LPS)-induced injury in Caenorhabditis elegans. Methods C. elegans individuals were stimulated for 24 h with LPS (100 μg/mL), with or without carnosine (0.1, 1, 10 mM). The survival rates and behaviors were determined. The activities of superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) and levels of malondialdehyde (MDA) and glutathione (GSH) were determined using the respective kits. Reverse transcription polymerase chain reaction (RT-PCR) was performed to validate the differential expression of sod-1, sod-2, sod-3, daf-16, ced-3, ced-9, sek-1, and pmk-1. Western blotting was used to determine the levels of SEK1, p38 mitogen-activated protein kinase (MAPK), cleaved caspase3, and Bcl-2. C. elegans sek-1 (km2) mutants and pmk-1 (km25) mutants were used to elucidate the role of the p38 MAPK signaling pathway. Results Carnosine improved the survival of LPS-treated C. elegans and rescued behavioral phenotypes. It also restrained oxidative stress by decreasing MDA levels and increasing SOD, GR, CAT, and GSH levels. RT-PCR results showed that carnosine treatment of wild-type C. elegans up-regulated the mRNA expression of the antioxidant-related genes sod-1, sod-2, sod-3, and daf-16. The expression of the anti-apoptosis-related gene ced-9 and apoptosis-related gene ced-3 was reversed by carnosine. In addition, carnosine treatment significantly decreased cleaved caspase3 levels and increased Bcl-2 levels in LPS-treated C. elegans. Apoptosis in the loss-of-function strains of the p38 MAPK signaling pathway was suppressed under LPS stress; however, the apoptotic effects of LPS were blocked in the sek-1 and pmk-1 mutants. The expression levels of sek-1 and pmk-1 mRNAs were up-regulated by LPS and reversed by carnosine. Finally, the expression of p-p38MAPK and SEK1 was significantly increased by LPS, which was reversed by carnosine. Conclusion Carnosine treatment protected against LPS injury by decreasing oxidative stress and inhibiting apoptosis through the p38 MAPK pathway.

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The DM Domain Transcription Factor MAB-3 Regulates Male Hypersensitivity to Oxidative Stress in Caenorhabditis elegans

Molecular and Cellular Biology ◽

10.1128/mcb.01459-09 ◽

2010 ◽

Vol 30 (14) ◽

pp. 3453-3459 ◽

Cited By ~ 8

Author(s):

Hideki Inoue ◽

Eisuke Nishida

Keyword(s):

Oxidative Stress ◽

Transcription Factor ◽

Caenorhabditis Elegans ◽

Sex Determination ◽

Target Genes ◽

Stress Sensitivity ◽

Gata Factor ◽

X Chromosomes ◽

C Elegans ◽

Dm Domain

ABSTRACT Sex differences occur in most species and involve a variety of biological characteristics. The nematode Caenorhabditis elegans consists of two sexes, self-fertile hermaphrodites (XX) and males (XO). Males differ from hermaphrodites in morphology, behavior, and life span. Here, we find that male C. elegans worms are much more sensitive than hermaphrodites to oxidative stress and show that the DM domain transcription factor MAB-3 plays a pivotal role in determining this male hypersensitivity. The hypersensitivity to oxidative stress does not depend on the dosage of X chromosomes but is determined by the somatic sex determination pathway. Our analyses show that the male hypersensitivity is controlled by MAB-3, one of the downstream effectors of the master terminal switch TRA-1 in the sex determination pathway. Moreover, we find that MAB-3 suppresses expression of several transcriptional target genes of the ELT-2 GATA factor, which is a global regulator of transcription in the C. elegans intestine, and show that RNA interference (RNAi) against elt-2 increases sensitivity to oxidative stress. These results strongly suggest that the DM domain protein MAB-3 regulates oxidative stress sensitivity by repressing transcription of ELT-2 target genes in the intestine.

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New strains for tissue-specific RNAi studies in Caenorhabditis elegans

10.1101/283325 ◽

2018 ◽

Author(s):

Jason S. Watts ◽

Henry F. Harrison ◽

Shizue Omi ◽

Quentin Guenthers ◽

James Dalelio ◽

...

Keyword(s):

Fatty Acid ◽

Caenorhabditis Elegans ◽

Gene Function ◽

Target Genes ◽

Resistant Mutant ◽

Knockout Mutant ◽

Tissue Specific ◽

Double Stranded Rna ◽

C Elegans ◽

Insight Into

AbstractRNA interference is a powerful tool for dissecting gene function. In Caenorhabditis elegans, ingestion of double stranded RNA causes strong, systemic knockdown of target genes. Further insight into gene function can be revealed by tissue-specific RNAi techniques. Currently available tissue-specific C. elegans strains rely on rescue of RNAi function in a desired tissue or cell in an otherwise RNAi deficient genetic background. We attempted to assess the contribution of specific tissues to polyunsaturated fatty acid (PUFA) synthesis using currently available tissue-specific RNAi strains. We discovered that rde-1 (ne219), a commonly used RNAi-resistant mutant strain, retains considerable RNAi capacity against RNAi directed at PUFA synthesis genes. By measuring changes in the fatty acid products of the desaturase enzymes that synthesize PUFAs, we found that the before mentioned strain, rde-1 (ne219) and the reported germline only RNAi strain, rrf-1 (pk1417) are not appropriate genetic backgrounds for tissue-specific RNAi experiments. However, the knockout mutant rde-1 (ne300) was strongly resistant to dsRNA induced RNAi, and thus is more appropriate for construction of a robust tissue-specific RNAi strains. Using newly constructed strains in the rde-1(null) background, we found considerable desaturase activity in intestinal, epidermal, and germline tissues, but not in muscle. The RNAi-specific strains reported in this study will be useful tools for C. elegans researchers studying a variety of biological processes.

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Caenorhabditis elegans: A Useful Model for Studying Metabolic Disorders in Which Oxidative Stress Is a Contributing Factor

Oxidative Medicine and Cellular Longevity ◽

10.1155/2014/705253 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 20

Author(s):

Elizabeth Moreno-Arriola ◽

Noemí Cárdenas-Rodríguez ◽

Elvia Coballase-Urrutia ◽

José Pedraza-Chaverri ◽

Liliana Carmona-Aparicio ◽

...

Keyword(s):

Oxidative Stress ◽

Caenorhabditis Elegans ◽

Metabolic Disorders ◽

Molecular Mechanisms ◽

Second Messengers ◽

Model Organism ◽

Human Diseases ◽

C Elegans ◽

Molecular Bases

Caenorhabditis elegansis a powerful model organism that is invaluable for experimental research because it can be used to recapitulate most human diseases at either the metabolic or genomic levelin vivo. This organism contains many key components related to metabolic and oxidative stress networks that could conceivably allow us to increase and integrate information to understand the causes and mechanisms of complex diseases. Oxidative stress is an etiological factor that influences numerous human diseases, including diabetes.C. elegansdisplays remarkably similar molecular bases and cellular pathways to those of mammals. Defects in the insulin/insulin-like growth factor-1 signaling pathway or increased ROS levels induce the conserved phase II detoxification response via the SKN-1 pathway to fight against oxidative stress. However, it is noteworthy that, aside from the detrimental effects of ROS, they have been proposed as second messengers that trigger the mitohormetic response to attenuate the adverse effects of oxidative stress. Herein, we briefly describe the importance ofC. elegansas an experimental model system for studying metabolic disorders related to oxidative stress and the molecular mechanisms that underlie their pathophysiology.

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Based on Network Pharmacology Tools to Investigate the Molecular Mechanism of Cordyceps sinensis on the Treatment of Diabetic Nephropathy

Journal of Diabetes Research ◽

10.1155/2021/8891093 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Yan Li ◽

Lei Wang ◽

Bojun Xu ◽

Liangbin Zhao ◽

Li Li ◽

...

Keyword(s):

Oxidative Stress ◽

Insulin Resistance ◽

Diabetic Nephropathy ◽

Inflammatory Response ◽

Signaling Pathway ◽

Molecular Mechanisms ◽

Target Genes ◽

Cordyceps Sinensis ◽

Network Pharmacology ◽

Active Ingredients

Background. Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus and is a major cause of end-stage kidney disease. Cordyceps sinensis (Cordyceps, Dong Chong Xia Cao) is a widely applied ingredient for treating patients with DN in China, while the molecular mechanisms remain unclear. This study is aimed at revealing the therapeutic mechanisms of Cordyceps in DN by undertaking a network pharmacology analysis. Materials and Methods. In this study, active ingredients and associated target proteins of Cordyceps sinensis were obtained via Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and Swiss Target Prediction platform, then reconfirmed by using PubChem databases. The collection of DN-related target genes was based on DisGeNET and GeneCards databases. A DN-Cordyceps common target interaction network was carried out via the STRING database, and the results were integrated and visualized by utilizing Cytoscape software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to determine the molecular mechanisms and therapeutic effects of Cordyceps on the treatment of DN. Results. Seven active ingredients were screened from Cordyceps, 293 putative target genes were identified, and 85 overlapping targets matched with DN were considered potential therapeutic targets, such as TNF, MAPK1, EGFR, ACE, and CASP3. The results of GO and KEGG analyses revealed that hub targets mainly participated in the AGE-RAGE signaling pathway in diabetic complications, TNF signaling pathway, PI3K-Akt signaling pathway, and IL-17 signaling pathway. These targets were correlated with inflammatory response, apoptosis, oxidative stress, insulin resistance, and other biological processes. Conclusions. Our study showed that Cordyceps is characterized as multicomponent, multitarget, and multichannel. Cordyceps may play a crucial role in the treatment of DN by targeting TNF, MAPK1, EGFR, ACE, and CASP3 signaling and involved in the inflammatory response, apoptosis, oxidative stress, and insulin resistance.

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Caenorhabditis elegans Exhibits Positive Gravitaxis

10.1101/658229 ◽

2019 ◽

Author(s):

Wei-Long Chen ◽

Hungtang Ko ◽

Han-Sheng Chuang ◽

Haim H. Bau ◽

David Raizen

Keyword(s):

Caenorhabditis Elegans ◽

Molecular Mechanisms ◽

Biological Effects ◽

Neural Mechanisms ◽

Mechanistic Studies ◽

Active Behavior ◽

C Elegans ◽

Sensory Cilia ◽

Hydrodynamic Effects ◽

Nematode Ecology

AbstractWhether or not the micro swimmer Caenorhabditis elegans senses and respond to gravity is unknown. We find that C. elegans aligns its swimming direction with that of the gravity vector (positive gravitaxis). When placed in an aqueous solution that is denser than the animals, they still orient downwards, indicating that non-uniform mass distribution and/or hydrodynamic effects are not responsible for animal’s downward orientation. Paralyzed worms and worms with globally disrupted sensory cilia do not change orientation as they settle in solution, indicating that gravitaxis is an active behavior that requires gravisensation. Other types of sensory driven orientation behaviors cannot explain our observed downward orientation. Like other neural behaviors, the ability to respond to gravity declines with age. Our study establishes gravitaxis in the micro swimmer C. elegans and suggests that C. elegans can be used as a genetically tractable system to study molecular and neural mechanisms of gravity sensing and orientation.Significance StatementUnderstanding how animals respond to gravity is not only of fundamental scientific interest, but has clinical relevance, given the prevalence of postural instability in aged individuals. Determining whether C. elegans responds to gravity is important for mechanistic studies of gravity sensing in an experimentally tractable animal, for a better understanding of nematode ecology and evolution, and for studying biological effects of microgravity. Our experiments, which indicate that C. elegans senses and responds to gravity, set the stage for mechanistic studies on molecular mechanisms of gravity sensing.

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New Strains for Tissue-Specific RNAi Studies in Caenorhabditis elegans

G3 Genes|Genome|Genetics ◽

10.1534/g3.120.401749 ◽

2020 ◽

Vol 10 (11) ◽

pp. 4167-4176 ◽

Cited By ~ 1

Author(s):

Jason S. Watts ◽

Henry F. Harrison ◽

Shizue Omi ◽

Quentin Guenthers ◽

James Dalelio ◽

...

Keyword(s):

Fatty Acid ◽

Caenorhabditis Elegans ◽

Gene Function ◽

Target Genes ◽

Resistant Mutant ◽

Knockout Mutant ◽

Tissue Specific ◽

C Elegans ◽

Link Type ◽

Insight Into

RNA interference is a powerful tool for dissecting gene function. In Caenorhabditis elegans, ingestion of double stranded RNA causes strong, systemic knockdown of target genes. Further insight into gene function can be revealed by tissue-specific RNAi techniques. Currently available tissue-specific C. elegans strains rely on rescue of RNAi function in a desired tissue or cell in an otherwise RNAi deficient genetic background. We attempted to assess the contribution of specific tissues to polyunsaturated fatty acid (PUFA) synthesis using currently available tissue-specific RNAi strains. We discovered that rde-1 (ne219), a commonly used RNAi-resistant mutant strain, retains considerable RNAi capacity against RNAi directed at PUFA synthesis genes. By measuring changes in the fatty acid products of the desaturase enzymes that synthesize PUFAs, we found that the before mentioned strain, rde-1 (ne219) and the reported germline only RNAi strain, rrf-1 (pk1417) are not appropriate genetic backgrounds for tissue-specific RNAi experiments. However, the knockout mutant rde-1 (ne300) was strongly resistant to dsRNA induced RNAi, and thus is more appropriate for construction of a robust tissue-specific RNAi strains. Using newly constructed strains in the rde-1(null) background, we found considerable desaturase activity in intestinal, epidermal, and germline tissues, but not in muscle. The RNAi-specific strains reported in this study will be useful tools for C. elegans researchers studying a variety of biological processes.

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Yersinia enterocolitica Infection and tcaA-Dependent Killing of Caenorhabditis elegans

Applied and Environmental Microbiology ◽

10.1128/aem.01274-10 ◽

2010 ◽

Vol 76 (18) ◽

pp. 6277-6285 ◽

Cited By ~ 23

Author(s):

Britta Spanier ◽

Mandy Starke ◽

Fabian Higel ◽

Siegfried Scherer ◽

Thilo M. Fuchs

Keyword(s):

Caenorhabditis Elegans ◽

Life Span ◽

Yersinia Enterocolitica ◽

Yersinia Pseudotuberculosis ◽

Fluorescent Protein ◽

Intestinal Lumen ◽

Knockout Mutant ◽

E Coli ◽

C Elegans ◽

Nematocidal Activity

ABSTRACT Caenorhabditis elegans is a validated model to study bacterial pathogenicity. We report that Yersinia enterocolitica strains W22703 (biovar 2, serovar O:9) and WA314 (biovar 1B, serovar O:8) kill C. elegans when feeding on the pathogens for at least 15 min before transfer to the feeding strain Escherichia coli OP50. The killing by Yersinia enterocolitica requires viable bacteria and, in contrast to that by Yersinia pestis and Yersinia pseudotuberculosis strains, is biofilm independent. The deletion of tcaA encoding an insecticidal toxin resulted in an OP50-like life span of C. elegans, indicating an essential role of TcaA in the nematocidal activity of Y. enterocolitica. TcaA alone is not sufficient for nematocidal activity because E. coli DH5α overexpressing TcaA did not result in a reduced C. elegans life span. Spatial-temporal analysis of C. elegans infected with green fluorescent protein-labeled Y. enterocolitica strains showed that Y. enterocolitica colonizes the nematode intestine, leading to an extreme expansion of the intestinal lumen. By low-dose infection with W22703 or DH5α followed by transfer to E. coli OP50, proliferation of Y. enterocolitica, but not E. coli, in the intestinal lumen of the nematode was observed. The titer of W22703 cells within the worm increased to over 106 per worm 4 days after infection while a significantly lower number of a tcaA knockout mutant was recovered. A strong expression of tcaA was observed during the first 5 days of infection. Y. enterocolitica WA314 (biovar 1B, serovar O:8) mutant strains lacking the yadA, inv, yopE, and irp1 genes known to be important for virulence in mammals were not attenuated or only slightly attenuated in their toxicity toward the nematode, suggesting that these factors do not play a significant role in the colonization and persistence of this pathogen in nematodes. In summary, this study supports the hypothesis that C. elegans is a natural host and nutrient source of Y. enterocolitica.

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Streblus asper Lour. exerts MAPK and SKN-1 mediated anti-aging, anti-photoaging activities and imparts neuroprotection by ameliorating Aβ in Caenorhabditis elegans

Nutrition and Healthy Aging ◽

10.3233/nha-210121 ◽

2021 ◽

pp. 1-17

Author(s):

Mani Iyer Prasanth ◽

James Michael Brimson ◽

Dicson Sheeja Malar ◽

Anchalee Prasansuklab ◽

Tewin Tencomnao

Keyword(s):

Oxidative Stress ◽

Caenorhabditis Elegans ◽

Stress Resistance ◽

Vital Role ◽

Transgenic Strain ◽

Wild Type ◽

Neuroprotective Effects ◽

C Elegans ◽

Streblus Asper

BACKGROUND: Streblus asper Lour., has been reported to have anti-aging and neuroprotective efficacies in vitro. OBJECTIVE: To analyze the anti-aging, anti-photoaging and neuroprotective efficacies of S. asper in Caenorhabditis elegans. METHODS: C. elegans (wild type and gene specific mutants) were treated with S. asper extract and analyzed for lifespan and other health benefits through physiological assays, fluorescence microscopy, qPCR and Western blot. RESULTS: The plant extract was found to increase the lifespan, reduce the accumulation of lipofuscin and modulate the expression of candidate genes. It could extend the lifespan of both daf-16 and daf-2 mutants whereas the pmk-1 mutant showed no effect. The activation of skn-1 was observed in skn-1::GFP transgenic strain and in qPCR expression. Further, the extract can extend the lifespan of UV-A exposed nematodes along with reducing ROS levels. Additionally, the extract also extends lifespan and reduces paralysis in Aβ transgenic strain, apart from reducing Aβ expression. CONCLUSIONS: S. asper was able to extend the lifespan and healthspan of C. elegans which was independent of DAF-16 pathway but dependent on SKN-1 and MAPK which could play a vital role in eliciting the anti-aging, anti-photoaging and neuroprotective effects, as the extract could impart oxidative stress resistance and neuroprotection.

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Caenorhabditis elegans as an in vivo Model to Assess Amphetamine Tolerance

Brain Behavior and Evolution ◽

10.1159/000514858 ◽

2021 ◽

pp. 1-9

Author(s):

Dayana Torres Valladares ◽

Sirisha Kudumala ◽

Murad Hossain ◽

Lucia Carvelli

Keyword(s):

Caenorhabditis Elegans ◽

Molecular Mechanisms ◽

Drugs Of Abuse ◽

Genetic Model ◽

In Vivo Model ◽

C Elegans ◽

Hyperactivity Disorder ◽

In Vitro Data

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.

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